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Two-Year Patient-Reported Outcomes for Patients Undergoing Revision Hip Arthroscopy with Capsular Incompetency
Two-Year Patient-Reported Outcomes for Patients Undergoing Revision Hip Arthroscopy with Capsular Incompetency Jourdan M. Cancienne, M.D., Edward C. Beck, M.D., M.P.H., Kyle N. Kunze, B.S., Jorge Chahla, M.D., Sunikom Suppauksorn, M.D., Katlynn Paul, and Shane J. Nho, M.D., M.S.
Purpose: To determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary surgery for femoroacetabular impingement syndrome (FAIS) at a minimum follow up of 2 years. Methods: Data from consecutive patients undergoing revision hip arthroscopy with MRI/arthrogram-confirmed capsular incompetency between January 2012 and June 2016 were analyzed. All revision patients with capsular incompetency was matched 1:1 by age and body mass index to FAIS revision patients without capsular incompetency and primary FAIS patients. Outcomes included the Hip Outcome Score (HOS)eActivities of Daily Living (ADL), HOS-Sports Subscale (SS), Modified Harris Hip Score (mHHS), pain, and satisfaction. The minimal clinically important difference was calculated for HOS-ADL, HOS-SS, and mHHS. Results: In total, 49 patients (54.4%) of 90 undergoing revision hip arthroscopy had MRI evidence of a capsular incompetency. Most patients were female (79.6%), with a mean age of 30 10.5 years and body mass index of 25.7 5.5. The difference among pre- and postoperative HOS-ADL, HOS-SS, mHHS, and visual analog scale score for pain were all statistically significant (P < .05). Analysis of reported outcomes among matched groups demonstrated statistically significant differences, with the group undergoing primary surgery having the greatest 2-year outcomes. Only 66.7% of patients undergoing revision surgery with capsular incompetency achieved a minimal clinically important difference; however, there was no significant difference when compared with revision patients without capsular incompetency. When compared with patients undergoing primary surgery, the difference in frequency was statistically significant (66.7% vs 91.3%; P < .001). Conclusions: More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients. Level of Evidence: Level III, Retrospective Comparative Study.
See commentary on page 137
H
ip arthroscopy continues to rapidly evolve due to advanced instrumentation and surgical technique. However, as with most surgical procedures, these
advancements are accompanied by unanticipated complications. Increasing hip arthroscopy literature has explored the relationship between capsular management
From the Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A. The authors report the following potential conflicts of interest or sources of funding: S.J.N. reports non-financial support from Allosource, other from the American Journal of Orthopedics, other from the American Orthopaedic Society for Sports Medicine, non-financial support from Arthrex, other from the Arthroscopy Association of North America, non-financial support from Athletico, non-financial support from DJ Orthopaedics, nonfinancial support from Linvatec, non-financial support from Miomed, personal fees from Ossur, non-financial support from Smith & Nephew, personal fees and non-financial support from Springer, and non-financial support from Stryker, outside the
submitted work. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Received March 25, 2019; accepted July 22, 2019. Address correspondence to Shane J. Nho, M.D., M.S., Department of Orthopaedics, Rush University Medical Center, 1611 West Harrison St., Suite 300, Chicago, IL 60612. E-mail: [email protected] or nho.research@ rushortho.com Ó 2019 by the Arthroscopy Association of North America 0749-8063/19397/$36.00 https://doi.org/10.1016/j.arthro.2019.07.026
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 36, No 1 (January), 2020: pp 127-136
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(FAIS) surgery at a minimum follow up of 2 years. The hypothesis was that revision hip arthroscopy with capsular repair in patients with capsular incompetency would lead to significantly improved functional outcomes similar to patients undergoing revision hip arthroscopy without capsular incompetency; however, such outcomes would be inferior to patients undergoing primary hip arthroscopy for FAI.
Methods Fig 1. Preoperative bilateral hip MRA. A coronal MRA of a pelvis indicting capsular incompetency in the right hip. The image demonstrates iliofemoral separation and retraction. The unaffected left hip can be used for comparison of an intact capsule. (MRA, magnetic resonance arthrogram.)
and postoperative iatrogenic hip instability and persistent pain as reasons for failure to clinically improve.1-4 Although there have been reports of frank anterior hip dislocations and chronic subluxations due to capsular incompetency following hip arthroscopy, others experience painful atraumatic microinstability that manifests as an overall failure to improve postoperatively.5-7 The ligaments that make up the hip capsule represent one of the primary static restraints that impart hip stability, with the iliofemoral ligament (IFL) being the strongest and most important anterior stabilizer.8 To increase visualization and access in the central compartment during hip arthroscopy, an interportal capsulotomy is typically made across this ligament connecting the anterolateral and anterior portals. Although nearly all surgeons create a capsulotomy, it has been reported that less than one half close the capsule at the conclusion of the case.9 Although the biomechanical importance of the IFL is well established, the clinical importance of its anatomic closure following hip arthroscopy has yet to be fully determined.10-12 Although residual femoroacetabular impingement (FAI) remains the most common diagnosis for revision hip arthroscopy, iatrogenic microinstability due to capsular deficiency is gaining increasing attention as a reason for revision surgery.1,7,13 This may be due to the ease of detection of residual FAI as compared with the challenge of identifying postoperative microinstability. The number of current studies investigating outcomes following revision hip arthroscopy due to capsular incompetency is extremely limited.1 Therefore, the goal of the current study was to determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary femoroacetabular impingement syndrome
Patient Selection The current study received institutional board approval (12022108-IRB01 Hip Injury and Arthritis Repository) to prospectively record and retrospectively analyze the outcomes of patients undergoing revision arthroscopic hip surgery for failure to improve with evidence of a capsular incompetency on postoperative MRI by a sports surgeon fellow and confirmed by a fellowship-trained surgeon (S.J.N.). Consecutive patients were enrolled between January 2012 and June 2016. Inclusion criteria consisted of patients with clinical criteria, physical findings, and imaging consistent with FAIS14; with a previous history of primary ipsilateral hip arthroscopy for femoroacetabular impingement; evidence of capsular incompetency on postoperative MRI; and a lateral center edge angle (LCEA) greater than 20 that failed to clinically improve following their primary surgery. The coronal and axial T1-weighted fat-saturated magnetic resonance arthrogram images taken after the primary surgery and before revision were reviewed and compared with intraoperative fluoroscopic images taken at the time of revision diagnostic hip arthroscopy to confirm capsular incompetency (Figs 1 and 2). Inspection of the capsular area between the anterolateral and anterior portal where previous capsulotomy was performed was inspected, and capsular incompetency was characterized by a gross deficiency of capsule as described previously by McCormick et al.4 Exclusion criteria for the study group included patients undergoing primary surgery, those with congenital or pediatric deformities (developmental dysplasia of the hip, slipped capital femoral epiphysis, and LeggeCalvéePerthes disease), Tönnis grade >1, those who underwent revision surgery without evidence of capsular incompetency, radiographic evidence of hip dysplasia (LCEA <20 ), and those less than 2 years out from the date of the revision surgery. Patients with evidence of capsular incompetency who underwent revision hip arthroscopy were then matched 1:1 by age and body mass index (BMI) to patients who underwent revision hip arthroscopy without MRI or intraoperative evidence of capsular incompetency and 1:1 by age and BMI to patients who underwent primary hip arthroscopy for FAIS.
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Fig 2. Preoperative unilateral MRA. An axial oblique MRA of a left hip demonstrating a capsular defect and extravasation of the dye into the extra-capsular tissue. (MRA, magnetic resonance arthrogram.)
Radiographic Analysis and Matching All patients had a series of preoperative radiographs and a series of final follow-up radiographs.15 Each series consisted of a standing anteroposterior (AP) pelvis radiograph, a false-profile hip radiograph, and a Dunn lateral hip radiograph.16 Alpha angle was measured on the AP, false profile, and Dunn lateral 45 view of the hip.17 Acetabular inclination (Tönnis angle), and LCEA were both measured on the AP hip radiograph.16,18 The Tönnis grade was determined.18,19 Anterior center edge angle (ACEA) was measured in the false-profile radiograph. The LCEA and ACEA was measured from the lateral edge of the bone as previously described.20
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Surgical Technique Revision arthroscopic hip surgery was performed with the patient under general anesthesia in the supine position on a standard traction table. The central compartment was accessed through the anterolateral and modified anterior portals. An interportal capsulotomy was performed as needed based on the amount of residual capsule present, from approximately 12 o’clock to 2 o’clock (Fig 3). A diagnostic arthroscopy was then performed with inspection of the labrum, chondral surfaces, acetabular rim, and remaining capsule. Associated pathology was treated as indicated. Next, traction was released, and the peripheral compartment inspected. All patients underwent a Tcapsulotomy above the zona orbicularis through the distal anterolateral accessory portal to enable appropriate femoral neck visualization for femoral osteochondroplasty. A suture-passing device (SlingShot Suture Manager; Stryker, Greenwood Village, CO) was used to reflect the capsule using a No. 2 highemolecular weight polyethylene sutures in the medial leaflet of the IFL and another in the lateral leaflet of the IFL. Both stitches were retrieved out of the anterolateral portal and tensioned with a hemostat against the skin. With the capsule reflected, any necessary osteochondroplasty of residual cam deformity was performed with excellent visualization of the peripheral compartment. Dynamic examination and fluoroscopic imaging were used to confirm that there was no further impingement and that headeneck offset was restored. Then the capsule was more completely inspected. Any adhesions or scar formation between the capsulolabral junction and capsule muscle intervals were lysed and released and mobility assessed. All of the capsular defects were closed by plication as previously described.21 The previously placed suspension stitches were unclamped and used to repair the interportal capsulotomy using the suture-passing device. All 3 stitches were retrieved and left united until after the vertical aspect of the T-capsulotomy is closed. Based on
Fig 3. Intra-articular arthroscopic images of the central compartment in a right hip demonstrates capsular incompetency. In both intra-articular arthroscopic images, the labrum (L), capsule (C), and femoral head (F) is visualized. In the image on the right, a probe is placed through the defect to point out the defect.
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Table 1. Postoperative Rehabilitation Protocol for Patients With FAIS Phase 1
Goal Protect the joint
Restrictions 20-lb foot-flat weight-bearing at 3 weeks Limit flexion, abduction, extension at 3 wk No active sitting greater than 30 min at 3 wk Work to avoid compensatory or gait
2
Noncompensatory gait progression and active ROM
3
Return to preinjury function
Avoid agility drills until week 10 Avoid hip rotational activities until week 10
4.
Return to sport
Muscle strength and full range of motion goals at week 12.
Techniques Soft-tissue mobilization Isometrics Joint mobilization Gait training Core strengthening/lumbar stabilization Scar mobilization Lumbar stabilization Elliptical at week 6 Single-leg squat Soft-tissue and joint mobilization Core strengthening Joint mobilization Gait training Soft-tissue and joint mobilizations Cardio, strength exercises Agility training Plyometrics Slow progression to return to presurgery level
FAIS, femoroacetabular impingement syndrome; ROM, range of motion.
the senior author’s experience, it is more difficult to pass stitches in the interportal cut after the vertical aspect is closed; therefore, we recommend passing these stitches but not tying until after the vertical capsulotomy is closed. The vertical T-limb of the T-capsulotomy is then closed, beginning at the base of the IFL using suture passing device loaded with a No. 2 highemolecular weight polyethylene suture. The suture passing device loaded with suture is inserted through the cannula in the distal anterolateral accessory portal and a full-thickness pass is made through the medial limb of the T-capsulotomy. The unloaded suture passing device is then reinserted through the distal anterolateral accessory portal, and a larger bite is then made through the lateral limb of the vertical portion at the base of the T-capsulotomy to retrieve the suture and passed it through the medial leaflet. The degree of leaflet overlap in the capsular plication performed depends on the degree of capsular laxity and dynamic intraoperative range of motion. A standard arthroscopic knot is then tied under direct visualization and cut. These steps are then repeated, and 2 more sutures are passed in the vertical portion of the T-capsulotomy. Depending on the size of the incision and integrity of the capsule, the vertical Tlimb is typically closed with 2 to 4 sutures. Lastly, the interportal limb of the T-capsulotomy was untagged, tied, and cut under direct visualization. Postoperative Rehabilitation Rehabilitation started on postoperative day 1 for all patients as previously described and did not differ from therapy indicated for primary FAIS cases.22,23 Patients went through a 4-phase rehabilitation protocol that lasted an average of 16-18 weeks (Table 1).
Functional Outcome Evaluation Before surgery, patient demographics were collected, including sex, age, operative extremity, BMI, sports participation, reason for primary surgery, duration from onset of symptoms to primary surgery, and comorbidities. Range of motion was measured with a goniometer. Patient-reported outcomes obtained preoperatively and at 2-year follow up included the Hip Outcome Score (HOS)dActivities of Daily Living (ADL), HOSdSports Subscale (SS), Modified Harris Hip Score (mHHS), and visual analog scales (VAS) for pain and satisfaction.24 To determine whether there was a difference in meaningful outcome improvement in the patients undergoing revision hip arthroscopy due to capsular incompetency, the minimal clinically important difference (MCID) was calculated. Similar to previous reports in the literature, a distribution based MCID was determined by calculating the ½ standard deviation of the HOS-ADL, HOS-SS, and mHHS in the study patients.25-32 Statistical Analysis Statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics for Windows, Version 22.0; IBM Corp., Armonk, NY). Continuous variables were presented as means with standard deviations. Paired t tests were used to compare preoperative with postoperative changes in patient-reported outcome scores. A c2 analysis was performed to analyze differences in categorical patient characteristics and achieving MCID among the different study groups. Categorical variables were presented as frequencies and percentages. A Tukey post-hoc analysis was used to
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OUTCOMES AFTER REVISION DUE TO CAPSULAR INSUFFICIENCY Table 2. Demographics of Patients Capsular With Incompetency Demographics Total Age, y* BMI* Sex Male Female Operative limb Left Right Procedures Isolated capsular management Labral repair Labral reconstruction Cam resection Microfracture
N/Mean 49 30.0 10.5 25.7 5.5 10 (20.4%) 39 (79.6%) 31 (63.3%) 18 (36.7%) 19 18 2 27 4
(38.8%) (36.7%) (4.1%) (55.1%) (8.2%)
BMI, body mass index. *Reported as mean standard deviation.
compare postoperative outcomes between cohorts. Finally, to control for between-group effects for postoperative patient-reported outcomes, a post-hoc analysis was performed to validate findings from the unmatched analysis. Statistical significance was set at a ¼ 0.05.
Results Baseline Characteristics Of the 90 patients reviewed who underwent revision hip arthroscopy, 49 patients had MRI and intraoperative evidence of a capsular incompetency. Of those, 40 (81.6%) completed 2-year follow up reported outcomes at with a mean time of 25 3.5 months. The majority of these patients were female (79.6%), had a mean age of 30 10.5 years, and had a BMI of 25.7 5.5 (Table 2). Two (4.1%) of the 49 patients with capsular incompetency had the primary surgery performed by the senior author, both of whom underwent partial capsular closure of the vertical portion of the T-capsulotomy. Table 3. Analysis of Pre- and Postoperative Radiographic Parameters Alpha angle (AP) Alpha angle (FP) Alpha angle (Dunn) LCEA ACEA Tönnis angle Tönnis grade 0 1
Preoperative 61.9 19.9 53.9 15.1 57.0 16.0 30.7 5.7 31.7 5.3 7.9 4.1
Postoperative 44.6 10.9 41.8 5.7 39.3 6.4 29.3 5.7 28.7 5.4 9.9 5.7
P Value <.001 <.001 <.001 .275 .014 .051
37 (92.5%) 3 (7.5%)
ACEA, anterior center edge angle; AP, anteroposterior; FP, false profile; LCEA, lateral center edge angle.
Of the 40 patients with 2-year follow up who underwent revision hip arthroscopy for capsular incompetency, 19 of those only required revision surgery for capsular management (debridement of capsular adhesions and capsular closure or capsular reconstruction). In total, 21 of the patients with capsular incompetency had concomitant cam impingement, with 18 having a labral re-tear that required repair. A total of 5 patients had acetabular chondromalacia, with only 1 having grade IV chondromalacia. Of note, 24 (48.9%) had no evidence of capsular closure during their index surgery. Radiographic Parameters Pre- and postoperative radiographic parameters, including the analysis comparing each, are described in Table 3. In brief, there was a statistically significant difference between pre- and postoperative alpha angle averages in each radiographic view (P < .001 for all). Although there was no significant difference in preand postoperative LCEA (30.7 5.7 vs 29.3 5.7; P ¼ .275) or Tönnis angle averages (7.9 4.1 vs 9.9 5.7; P ¼ .051), there was a statistically significant difference in ACEA averages (31.7 5.3 vs 28.7 5.4; P ¼ .014). Of note, there were no patients with hip dysplasia as defined by LCEA or ACEA <20 . Functional Outcomes Preoperatively, the averages for the HOS-ADL, HOSSS, and mHHS were 64.7 19.7, 35.5 28.1, and 51.6 21.0, respectively. Postoperatively, these averages were 77.8 23.3, 57.0 31.6, and 71.9 22.3, respectively. The differences among pre- and postoperative HOS-ADL, HOS-SS, and mHHS were all statistically significant (P < .001). There was also a statistically significant decrease in the VAS pain score (72.8 14.5 vs 27.9 23.0; P < .001) (Table 4). Subanalysis of pre- and postoperative outcomes among revision patients undergoing revision solely due to capsular incompetency versus those with capsular incompetency and concomitant pathology did not show any statistically significant difference (Table 5).
Table 4. Patient-Reported Outcome Measures at a Minimum of 2 Years’ Postoperatively Relative to Preoperative Baseline Scores Preoperative Outcome HOS-ADL HOS-SS mHHS VAS pain VAS satisfaction
64.7 35.5 51.6 72.8
e
19.7 28.1 21.0 14.5
Postoperative
P Value
<.001 <.001 <.001 <.001 e
77.8 57.0 71.9 27.9 73.4
23.3 31.6 22.3 23.0 37.9
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score; VAS, visual analog scale.
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Table 5. Comparison of Pre- and Postoperative Outcomes in Patients With Capsular Incompetency Alone Versus Patients With Other Concomitant Pathology
Preoperative HOS-ADL HOS-SS mHHS VAS pain Postoperative HOS-ADL HOS-SS mHHS VAS pain VAS satisfaction
Revision due to Capsular Incompetency þ Concomitant Pathology e 68.1 17.4 46.47 26.6 60.6 12.1 73.6 13.0 e 78.6 19.5 61.6 29.6 73.3 25.1 25.5 25.3 69.8 36.0
Revision due to Capsular Incompetency e 65.6 16.9 39.1 20.2 58.2 13.3 72.5 14.2 e 76.9 16.2 54.8 29.5 69.2 17.3 31.2 24.3 70.8 36.5
P Value e .767 .126 .404 .528 e .831 .214 .383 .279 .912
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score; VAS, visual analog scale.
Match-Paired Analysis A one-way analysis of variance revealed sufficient matching based off of baseline demographic characteristics. There were no statistically significant differences among the 3 cohorts when comparing preoperative patient-reported outcome measures (Table 6). However, patients who underwent primary hip arthroscopy had significantly superior postoperative outcomes than both revision cohorts. Furthermore, the post-hoc
Table 6. One-way Analysis of Variance for Match-Paired Cohorts Capsular Other Revision Incompetency Causes No./mean Overall 40 Demographics Age 32.4 10.6 BMI 26.14 5.6 Female sex 31 (77.5%) Preoperative HOS-ADL 64.7 19.7 HOS-SS 42.1 27.4 mHHS 59.2 16.5 Pain 72.8 14.5 Postoperative HOS-ADL 77.8 23.3 HOS-SS 57.0 31.6 mHHS 71.9 25.5 Pain 27.9 23.0 satisfaction 70.2 16.3
Primary Cases
No./mean 41
No./mean 40
P Value
33.1 12.3 22.4 8.6 27 (65.9%)
32.3 10.1 25.4 3.9 26 (65%)
.822 .453 .418
60.3 34.7 52.9 73.4
15.9 24.2 17.1 13.9
69.5 43.8 60.4 6.5
15.2 20.8 14.6 1.7
.086 .349 .263 .226
74.7 52.3 64.7 30.9 73.4
23.2 31.9 22.8 28.0 37.9
92.8 83.4 83.9 16.2 82.6
7.7 16.8 12.9 20.4 21.3
<.001 <.001 <.001 <.001 .001
NOTE. Boldface indicates statistical significance. BMI, body mass index; HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score.
Table 7. MCID Rates for Patients With Capsular Incompetency Versus Patients Undergoing Revision for Other Causes
HOS-ADL HOS-SS mHHS Any MCID threshold achieved
Revisions due to Capsular Incompetency 55.6% 37.5% 52.2% 69.7%
Other Revision Causes 60% 52.2% 52.4% 73.1%
P Value .730 .312 .989 .589
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; MCID, minimal clinically important difference; mHHS, Modified Harris Hip Score.
analysis confirmed the finding from the unmatched analysis that there were no statistically significant differences in postoperative patient-reported outcomes between the 3 revision cohorts. MCID Analysis The MCID threshold values for HOS-ADL, HOS-SS, and mHHS specific to the study group with capsular incompetency were 13.6, 16.8, and 11.2, respectively. The change in 2-year patient-reported outcomes for achieving MCID scores in the non-BHD group were 13.1, 17.1, and 11.2, respectively. c2 analysis demonstrated that there was no statistically significant difference between the frequency of patients achieving MCID in both groups (Table 7). The MCID threshold values for HOS-ADL, HOS-SS, and mHHS specific to the matched study group undergoing primary repair were 8.0, 13.3, and 9.4, respectively. c2 analysis demonstrated that patients undergoing primary hip arthroscopy had greater frequency of achieving MCID for all patient-reported outcomes when compared with patients undergoing revisions for capsular incompetency (Table 8). Complications and Reoperations A total of 2 patients (4.1%) developed postoperative complications and 1 patient (2.0%) required a reoperation. One complication included persistent mechanical Table 8. MCID Rates for Patients With Capsular Incompetency Versus Patients Undergoing Primary Hip Arthroscopy
HOS-ADL HOS-SS mHHS Any MCID threshold achieved
Revisions due to Primary Capsular Incompetency Cases P Value 55.6% 88.2% <.001 37.5% 91.4% <.001 52.2% 73.0% <.001 69.7% 89.9% <.001
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; MCID, minimal clinically important difference; mHHS, Modified Harris Hip Score.
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symptoms, and the second was due to development of a peripheral neuropathy of the ipsilateral operative limb that subsequently resolved. One revision surgery was performed within 2 years due to mechanical symptoms and persistent pain following a contact sport injury. Intraoperative findings demonstrated continued capsular incompetency requiring capsular reconstruction with a dermal allograft (ArthroFlex; Arthrex, Napes, FL) augmentation as previously described.33 This represents the only patient in this series who underwent capsular reconstruction.
Discussion The main findings of this study were that revision hip arthroscopy with capsular repair for capsular incompetency resulted in significantly improved 2-year postoperative patient-reported outcomes and achieved MCID at similar rates comparable with patients undergoing revisions without capsular incompetency. However, patients undergoing revision for capsular incompetency have significantly lower 2-year patientreported outcome averages and achieve MCID and lower rates than matched patients undergoing primary hip arthroscopy. In addition, we also found that more than one half (54.4%) of hip arthroscopy patients undergoing revision surgery had evidence of a capsular incompetency on preoperative imaging and at the time of revision surgery. Revision hip arthroscopy is a complex, multifactorial decision that requires a thorough understanding of the etiologies of failure. Some of the factors that must be considered include capsular status, presence of dysplasia, and femoral anteversion, among others. Recent literature has reported success with periacetabular osteotomy following failed hip arthroscopy, and this operation must be considered in the presence of dysplasia.34 Nonetheless, increasing evidence continues to demonstrate that microinstability exists even without dysplasia.35 Therefore, in the current study, we attempted to isolate patients with a structurally incompetent capsule without significant dysplasia who underwent revision arthroscopy and sought to compare clinical outcomes with patients with intact capsules. Over the past couple of years, there has been a shift in the orthopaedic literature toward identifying postsurgical meaningful improvement rather than statistical improvement.25,28-32,36 In this study, the MCID was identified for both patients undergoing revisions for capsular incompetency and for those without using the ½ standard deviation of the change in functional scores over a 2-year period.37,38 Previous literature has demonstrated that meaningful clinical threshold values vary based on disease.37,38 Although the MCID values of patient undergoing revision surgery with and without capsular incompetency were not identical, the difference was very modest and not statistically
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significant. This further provides evidence that patients undergoing revisions for capsular incompetency can achieve similar clinical improvements when compared with revision patients without capsular incompetency. Atraumatic instability following hip arthroscopy is a challenging and likely underrecognized complication of hip arthroscopy that has gained increasing attention in the recent literature.1,3,7,10 Although the most common indication for revision hip arthroscopy remains residual FAI, the current study found that capsular incompetency may be a component of more than one half of the revision surgeries performed by a high-volume, fellowship-trained surgeon.39-42 The mechanism by which capsular incompetency and instability can lead to revision surgery has been previously established. Biomechanical studies have shown that capsulotomy at the time of hip arthroscopy increases motion of the hip in multiple planes, placing increasing stress on the labrum as a secondary stabilizer.43,44 Thus, patients with subtle microinstability due to capsular incompetency may present with recurrent labral tears and failure to improve after primary surgery. Despite the increasing acceptance and awareness of both microinstability and capsular incompetency in hip arthroscopy, the detection of such pathology remains challenging, especially in the absence of bony abnormalities or a connective tissue disorder.35 Recent literature has described 6 specific maneuvers to help evaluate hip stability: the anterior apprehension test, abductioneextensioneexternal rotation test, prone external rotation test, log roll test, axial distraction test, and the posterior apprehension test.35 Although these signs may be present and microinstability may exist, it is difficult to determine whether the presence of capsular competence can equal cause for such instability. In the current study, it is likely that many patients were experiencing components of both microinstability and capsular incompetency, resulting in their failure to improve. Previous studies have demonstrated that evidence of capsular closure is observed in both patients with capsular repair and leaving the capsule intact after interportal capsulotomy. Using MRI, Strickland et al.45 compared 15 hips with capsular closure of interportal capsulotomies with 15 with the capsule intact and demonstrated that both demonstrated healing with a contiguous appearance at 24 weeks after surgery. The limitations of radiographic studies such as this include the underpowered analysis caused by a small number of patients in the study group, and based their findings on radiographic evidence that is unable to capture capsular adhesions and small capsular incompetency that can cause refractory pain.46 Moreover, the impact of radiographic studies such as this is limited by not factoring patient clinical function and outcome. Our study demonstrates that patients undergoing revision
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arthroscopy with both isolated cases of capsular incompetency and concomitant pathology have similar improvement in function compared with patients without capsular incompetency undergoing revision surgery. In recent years, closure continues to gain popularity following primary arthroscopic hip surgery, and evidence on outcomes of revision hip arthroscopy secondary due to capsular incompetency has continued to grow as well. Frank et al.47 demonstrated that patients with complete capsular closure report greater HOS-SS values at 2 years compared with patients with an unrepaired interportal capsulotomy. Wylie et al.1 reviewed a cohort of 1100 patients who underwent primary hip arthroscopy and identified 33 who developed postoperative symptomatic instability due to capsular incompetency requiring revision surgery. Similar to the present study, revision surgery consisted of addressing the untreated bony or labral lesions and capsular repair with nonabsorbable suture. Of these patients, 11 had a minimum 2year follow-up. The group reported significantly improved mHHS, HOS-ADL, and HOS-SS outcome scores following revision capsular closure. Larson et al.41 studied their own cohort of revision hip arthroscopy patients and identified 23 hips (27%) with previous unrepaired capsulotomies. Although the group did not isolate this subset of patients, they reported that capsular closure was an independent predictor of improved outcomes after revision surgery. The present study adds valuable data and insight to revision surgery for capsular incompetency. Our study is one of the largest in the literature to specifically look at revision hip arthroscopy for capsular repair in patients with persistent pain and a capsular incompetency on both preoperative MRI and at the time of surgery. With all patients demonstrating significant postoperative improvements compared with preoperative baseline scores, we further highlight the importance of capsular management and closure. To better understand the effects of capsular repair, we furthered our analysis by comparing our study cohort with revision patients without capsular incompetency and patients undergoing primary surgery. With appropriate capsular management in a revision setting, patients with capsular incompetency can expect similar outcomes at 2 years as their counterparts undergoing revision surgery with an intact, healed capsule. However, as has been previously established, outcomes following revision hip arthroscopy will not produce clinical outcomes equivalent to that of primary hip arthroscopy patients, regardless of capsular integrity at the time of revision surgery. Limitations There are several limitations to the current study. First, an a priori analysis was not performed, and
therefore an effect size has not been established for any variable to calculate the necessary population size for observed power of >0.8. A post-hoc power analysis in this study is dependent on what comparison is chosen to calculate the effect size for determining the observed power. When using the postoperative HOS-ADL score of primary cases and revisions due to capsular defect, the effect size (Cohen’s d) is equal to 0.89086, and the observed power for a 2-tailed hypothesis is 0.992. If the pre- and postoperative HOS-ADL scores for patients undergoing revisions for capsular deficiency were used, the effect size (Cohen’s d) is equal to 0.60.717, and the observed power for a 2-tailed hypothesis is 0.844. However, these power analyses may not be applicable to all the t tests performed in this study, and it may be possible that some of the analysis is underpowered. Second, the number of patients with isolated capsular incompetency undergoing capsular repair was relatively small, and we had to combine them with patients undergoing revision for capsular incompetency and other concomitant pathology for the main analysis of the study including calculation of MCID. In addition, given the limited number of patients available to study, we were unable to exactly sex-match. Although the groups were statistically similar in female predominance, they were not exactly sex-matched, and this may influence our results. Third, although the revision cohort studied showed capsular incompetency on MRI, there was also residual impingement in a large percentage of patients. Although it is beyond the scope of the current study to distinguish whether capsular incompetency or residual impingement resulted in the failure to improve following their primary surgery, the 2 are likely interrelated and each must be considered and treated at the time of revision surgery to improve patient outcomes. Finally, although all of the revision patients had complete capsular management including capsular closure, some required capsular reconstruction due to significant incompetency, whereas most were able to be closed primarily. Unfortunately, the numbers of patients with capsular reconstruction were not enough to compare outcomes with patients who underwent primary closure. This is a substantially greater degree of surgery and one might expect inferior outcomes in these patients, thus skewing our results.
Conclusions More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients.
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References 1. Wylie JD, Beckmann JT, Maak TG, Aoki SK. Arthroscopic capsular repair for symptomatic hip instability after previous hip arthroscopic surgery. Am J Sports Med 2016;44: 39-45. 2. Cvetanovich GL, Weber AE, Kuhns BD, et al. Hip Arthroscopic surgery for femoroacetabular impingement with capsular management: Factors associated with achieving clinically significant outcomes. Am J Sports Med 2018;46:288-296. 3. Domb BG, Philippon MJ, Giordano BD. Arthroscopic capsulotomy, capsular repair, and capsular plication of the hip: Relation to atraumatic instability. Arthroscopy 2013;29:162-173. 4. McCormick F, Slikker W 3rd, Harris JD, et al. Evidence of capsular defect following hip arthroscopy. Knee Surg Sports Traumatol Arthrosc 2014;22:902-905. 5. Benali Y, Katthagen BD. Hip subluxation as a complication of arthroscopic debridement. Arthroscopy 2009;25: 405-407. 6. Mei-Dan O, McConkey MO, Brick M. Catastrophic failure of hip arthroscopy due to iatrogenic instability: Can partial division of the ligamentum teres and iliofemoral ligament cause subluxation? Arthroscopy 2012;28:440-445. 7. Philippon MJ, Schenker ML, Briggs KK, Kuppersmith DA, Maxwell RB, Stubbs AJ. Revision hip arthroscopy. Am J Sports Med 2007;35:1918-1921. 8. Bowman KF Jr, Fox J, Sekiya JK. A clinically relevant review of hip biomechanics. Arthroscopy 2010;26: 1118-1129. 9. Smith KM, Gerrie BJ, McCulloch PC, et al. Arthroscopic hip preservation surgery practice patterns: An international survey. J Hip Preserv Surg 2017;4:18-29. 10. Ortiz-Declet V, Mu B, Chen AW, et al. Should the capsule be repaired or plicated after hip arthroscopy for labral tears associated with femoroacetabular impingement or instability? A systematic review. Arthroscopy 2018;34: 303-318. 11. Westermann RW, Bessette MC, Lynch TS, Rosneck J. Does closure of the capsule impact outcomes in hip arthroscopy? A systematic review of comparative studies. Iowa Orthop J 2018;38:93-99. 12. Chahla J, Mikula JD, Schon JM, et al. Hip capsular closure: A biomechanical analysis of failure torque. Am J Sports Med 2017;45:434-439. 13. Bolia I, Chahla J, Locks R, Briggs K, Philippon MJ. Microinstability of the hip: A previously unrecognized pathology. Muscles Ligaments Tendons J 2016;6:354-360. 14. Griffin DR, Dickenson EJ, O’Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): An international consensus statement. Br J Sports Med 2016;50:1169-1176. 15. Weber AE, Jacobson JA, Bedi A. A review of imaging modalities for the hip. Curr Rev Musculoskelet Med 2013;6: 226-234. 16. Clohisy JC, Carlisle JC, Beaule PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am 2008;90:47-66 (suppl 4). 17. Notzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J. The contour of the femoral head-neck junction
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
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as a predictor for the risk of anterior impingement. J Bone Joint Surg Br 2002;84:556-560. Krych AJ, Thompson M, Knutson Z, Scoon J, Coleman SH. Arthroscopic labral repair versus selective labral debridement in female patients with femoroacetabular impingement: A prospective randomized study. Arthroscopy 2013;29:46-53. Tonnis D, Heinecke A, Nienhaus R, Thiele J. [Predetermination of arthrosis, pain and limitation of movement in congenital hip dysplasia (author’s transl)]. Z Orthop Ihre Grenzgeb 1979;117:808-815. Sakai T, Nishii T, Sugamoto K, Yoshikawa H, Sugano N. Is vertical-center-anterior angle equivalent to anterior coverage of the hip? Clin Orthop Relat Res 2009;467:2865-2871. Levy DM, Grzybowski J, Salata MJ, Mather RC, Aoki SK, Nho SJ. Capsular plication for treatment of iatrogenic hip instability. Arthrosc Tech 2015;4:e625-e630. Malloy P, Gray K, Wolff AB. Rehabilitation after hip arthroscopy: A movement control-based perspective. Clin Sports Med 2016;35:503-521. Leong NL, Clapp IM, Neal WH, Beck E, Bush-Joseph CA, Nho SJ. The influence of pain in other major joints and the spine on 2-year outcomes after hip arthroscopy. Arthroscopy 2018;34:3196-3201. Martin RL, Philippon MJ. Evidence of reliability and responsiveness for the hip outcome score. Arthroscopy 2008;24:676-682. Nwachukwu BU, Fields K, Chang B, Nawabi DH, Kelly BT, Ranawat AS. Preoperative outcome scores are predictive of achieving the minimal clinically important difference after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2017;45:612-619. Levy DM, Cvetanovich GL, Kuhns BD, Greenberg MJ, Alter JM, Nho SJ. Hip arthroscopy for atypical posterior hip pain: A comparative matched-pair analysis. Am J Sports Med 2017;45:1627-1632. Katz NP, Paillard FC, Ekman E. Determining the clinical importance of treatment benefits for interventions for painful orthopedic conditions. J Orthop Surg Res 2015;10:24. Nwachukwu BU, Chang B, Adjei J, et al. Time required to achieve minimal clinically important difference and substantial clinical benefit after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2018;46: 2601-2606. Nwachukwu BU, Chang B, Fields K, et al. Defining the "substantial clinical benefit" after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2017;45:1297-1303. Nwachukwu BU, Chang B, Kahlenberg CA, et al. Arthroscopic treatment of femoroacetabular impingement in adolescents provides clinically significant outcome improvement. Arthroscopy 2017;33:1812-1818. Nwachukwu BU, Chang B, Voleti PB, et al. Preoperative short form health survey score is predictive of return to play and minimal clinically important difference at a minimum 2-year follow-up after anterior cruciate ligament reconstruction. Am J Sports Med 2017;45:2784-2790. Nwachukwu BU, Chang B, Beck EC, et al. How should we define clinically significant outcome improvement on the iHOT-12? HSS J 2019;15:103-108.
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33. Chahla J, Dean CS, Soares E, Mook WR, Philippon MJ. Hip capsular reconstruction using dermal allograft. Arthrosc Tech 2016;5:e365-e369. 34. Novais EN, Coobs BR, Nepple JJ, Clohisy JC, Group AS. Previous failed hip arthroscopy negatively impacts early patient-reported outcomes of the periacetabular osteotomy: An ANCHOR Matched Cohort Study. J Hip Preserv Surg 2018;5:370-377. 35. Safran MR. Microinstability of the hipdgaining acceptance. J Am Acad Orthop Surg 2019;27:12-22. 36. Cvetanovich GL, Weber AE, Kuhns BD, et al. Clinically meaningful improvements after hip arthroscopy for femoroacetabular impingement in adolescent and young adult patients regardless of gender. J Pediatr Orthop 2018;38:465-470. 37. Leopold SS. Editor’s spotlight/take 5: Comparative responsiveness and minimal clinically important differences for idiopathic ulnar impaction syndrome. Clin Orthop Relat Res 2013;471:1403-1405. 38. Kosinski M, Zhao SZ, Dedhiya S, Osterhaus JT, Ware JE Jr. Determining minimally important changes in generic and disease-specific health-related quality of life questionnaires in clinical trials of rheumatoid arthritis. Arthritis Rheum 2000;43:1478-1487. 39. Ross JR, Larson CM, Adeoye O, Kelly BT, Bedi A. Residual deformity is the most common reason for revision hip arthroscopy: A three-dimensional CT study. Clin Orthop Relat Res 2015;473:1388-1395. 40. Sardana V, Philippon MJ, de Sa D, et al. Revision hip arthroscopy indications and outcomes: A systematic review. Arthroscopy 2015;31:2047-2055.
41. Larson CM, Giveans MR, Samuelson KM, Stone RM, Bedi A. Arthroscopic hip revision surgery for residual femoroacetabular impingement (FAI): Surgical outcomes compared with a matched cohort after primary arthroscopic FAI correction. Am J Sports Med 2014;42: 1785-1790. 42. Bogunovic L, Gottlieb M, Pashos G, Baca G, Clohisy JC. Why do hip arthroscopy procedures fail? Clin Orthop Relat Res 2013;471:2523-2529. 43. Bayne CO, Stanley R, Simon P, et al. Effect of capsulotomy on hip stability-a consideration during hip arthroscopy. Am J Orthop (Belle Mead NJ) 2014;43: 160-165. 44. Myers CA, Register BC, Lertwanich P, et al. Role of the acetabular labrum and the iliofemoral ligament in hip stability: an in vitro biplane fluoroscopy study. Am J Sports Med 2011;39:85S-91S (suppl). 45. Strickland CD, Kraeutler MJ, Brick MJ, et al. MRI evaluation of repaired versus unrepaired interportal capsulotomy in simultaneous bilateral hip arthroscopy: A double-blind, randomized controlled trial. J Bone Joint Surg Am 2018;100:91-98. 46. Shin JJ, de Sa DL, Burnham JM, Mauro CS. Refractory pain following hip arthroscopy: Evaluation and management. J Hip Preserv Surg 2018;5:3-14. 47. Frank RM, Lee S, Bush-Joseph CA, Kelly BT, Salata MJ, Nho SJ. Improved outcomes after hip arthroscopic surgery in patients undergoing T-capsulotomy with complete repair versus partial repair for femoroacetabular impingement: A comparative matched-pair analysis. Am J Sports Med 2014;42:2634-2642.
Purpose: To determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary surgery for femoroacetabular impingement syndrome (FAIS) at a minimum follow up of 2 years. Methods: Data from consecutive patients undergoing revision hip arthroscopy with MRI/arthrogram-confirmed capsular incompetency between January 2012 and June 2016 were analyzed. All revision patients with capsular incompetency was matched 1:1 by age and body mass index to FAIS revision patients without capsular incompetency and primary FAIS patients. Outcomes included the Hip Outcome Score (HOS)eActivities of Daily Living (ADL), HOS-Sports Subscale (SS), Modified Harris Hip Score (mHHS), pain, and satisfaction. The minimal clinically important difference was calculated for HOS-ADL, HOS-SS, and mHHS. Results: In total, 49 patients (54.4%) of 90 undergoing revision hip arthroscopy had MRI evidence of a capsular incompetency. Most patients were female (79.6%), with a mean age of 30 10.5 years and body mass index of 25.7 5.5. The difference among pre- and postoperative HOS-ADL, HOS-SS, mHHS, and visual analog scale score for pain were all statistically significant (P < .05). Analysis of reported outcomes among matched groups demonstrated statistically significant differences, with the group undergoing primary surgery having the greatest 2-year outcomes. Only 66.7% of patients undergoing revision surgery with capsular incompetency achieved a minimal clinically important difference; however, there was no significant difference when compared with revision patients without capsular incompetency. When compared with patients undergoing primary surgery, the difference in frequency was statistically significant (66.7% vs 91.3%; P < .001). Conclusions: More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients. Level of Evidence: Level III, Retrospective Comparative Study.
See commentary on page 137
H
ip arthroscopy continues to rapidly evolve due to advanced instrumentation and surgical technique. However, as with most surgical procedures, these
advancements are accompanied by unanticipated complications. Increasing hip arthroscopy literature has explored the relationship between capsular management
From the Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois, U.S.A. The authors report the following potential conflicts of interest or sources of funding: S.J.N. reports non-financial support from Allosource, other from the American Journal of Orthopedics, other from the American Orthopaedic Society for Sports Medicine, non-financial support from Arthrex, other from the Arthroscopy Association of North America, non-financial support from Athletico, non-financial support from DJ Orthopaedics, nonfinancial support from Linvatec, non-financial support from Miomed, personal fees from Ossur, non-financial support from Smith & Nephew, personal fees and non-financial support from Springer, and non-financial support from Stryker, outside the
submitted work. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Received March 25, 2019; accepted July 22, 2019. Address correspondence to Shane J. Nho, M.D., M.S., Department of Orthopaedics, Rush University Medical Center, 1611 West Harrison St., Suite 300, Chicago, IL 60612. E-mail: [email protected] or nho.research@ rushortho.com Ó 2019 by the Arthroscopy Association of North America 0749-8063/19397/$36.00 https://doi.org/10.1016/j.arthro.2019.07.026
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 36, No 1 (January), 2020: pp 127-136
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(FAIS) surgery at a minimum follow up of 2 years. The hypothesis was that revision hip arthroscopy with capsular repair in patients with capsular incompetency would lead to significantly improved functional outcomes similar to patients undergoing revision hip arthroscopy without capsular incompetency; however, such outcomes would be inferior to patients undergoing primary hip arthroscopy for FAI.
Methods Fig 1. Preoperative bilateral hip MRA. A coronal MRA of a pelvis indicting capsular incompetency in the right hip. The image demonstrates iliofemoral separation and retraction. The unaffected left hip can be used for comparison of an intact capsule. (MRA, magnetic resonance arthrogram.)
and postoperative iatrogenic hip instability and persistent pain as reasons for failure to clinically improve.1-4 Although there have been reports of frank anterior hip dislocations and chronic subluxations due to capsular incompetency following hip arthroscopy, others experience painful atraumatic microinstability that manifests as an overall failure to improve postoperatively.5-7 The ligaments that make up the hip capsule represent one of the primary static restraints that impart hip stability, with the iliofemoral ligament (IFL) being the strongest and most important anterior stabilizer.8 To increase visualization and access in the central compartment during hip arthroscopy, an interportal capsulotomy is typically made across this ligament connecting the anterolateral and anterior portals. Although nearly all surgeons create a capsulotomy, it has been reported that less than one half close the capsule at the conclusion of the case.9 Although the biomechanical importance of the IFL is well established, the clinical importance of its anatomic closure following hip arthroscopy has yet to be fully determined.10-12 Although residual femoroacetabular impingement (FAI) remains the most common diagnosis for revision hip arthroscopy, iatrogenic microinstability due to capsular deficiency is gaining increasing attention as a reason for revision surgery.1,7,13 This may be due to the ease of detection of residual FAI as compared with the challenge of identifying postoperative microinstability. The number of current studies investigating outcomes following revision hip arthroscopy due to capsular incompetency is extremely limited.1 Therefore, the goal of the current study was to determine clinical outcomes of patients undergoing revision hip arthroscopy for failure to improve with magnetic resonance imaging (MRI) and intraoperative evidence of a capsular incompetency as compared with (1) patients undergoing revision hip arthroscopy without evidence of a capsular incompetency and (2) patients undergoing primary femoroacetabular impingement syndrome
Patient Selection The current study received institutional board approval (12022108-IRB01 Hip Injury and Arthritis Repository) to prospectively record and retrospectively analyze the outcomes of patients undergoing revision arthroscopic hip surgery for failure to improve with evidence of a capsular incompetency on postoperative MRI by a sports surgeon fellow and confirmed by a fellowship-trained surgeon (S.J.N.). Consecutive patients were enrolled between January 2012 and June 2016. Inclusion criteria consisted of patients with clinical criteria, physical findings, and imaging consistent with FAIS14; with a previous history of primary ipsilateral hip arthroscopy for femoroacetabular impingement; evidence of capsular incompetency on postoperative MRI; and a lateral center edge angle (LCEA) greater than 20 that failed to clinically improve following their primary surgery. The coronal and axial T1-weighted fat-saturated magnetic resonance arthrogram images taken after the primary surgery and before revision were reviewed and compared with intraoperative fluoroscopic images taken at the time of revision diagnostic hip arthroscopy to confirm capsular incompetency (Figs 1 and 2). Inspection of the capsular area between the anterolateral and anterior portal where previous capsulotomy was performed was inspected, and capsular incompetency was characterized by a gross deficiency of capsule as described previously by McCormick et al.4 Exclusion criteria for the study group included patients undergoing primary surgery, those with congenital or pediatric deformities (developmental dysplasia of the hip, slipped capital femoral epiphysis, and LeggeCalvéePerthes disease), Tönnis grade >1, those who underwent revision surgery without evidence of capsular incompetency, radiographic evidence of hip dysplasia (LCEA <20 ), and those less than 2 years out from the date of the revision surgery. Patients with evidence of capsular incompetency who underwent revision hip arthroscopy were then matched 1:1 by age and body mass index (BMI) to patients who underwent revision hip arthroscopy without MRI or intraoperative evidence of capsular incompetency and 1:1 by age and BMI to patients who underwent primary hip arthroscopy for FAIS.
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Fig 2. Preoperative unilateral MRA. An axial oblique MRA of a left hip demonstrating a capsular defect and extravasation of the dye into the extra-capsular tissue. (MRA, magnetic resonance arthrogram.)
Radiographic Analysis and Matching All patients had a series of preoperative radiographs and a series of final follow-up radiographs.15 Each series consisted of a standing anteroposterior (AP) pelvis radiograph, a false-profile hip radiograph, and a Dunn lateral hip radiograph.16 Alpha angle was measured on the AP, false profile, and Dunn lateral 45 view of the hip.17 Acetabular inclination (Tönnis angle), and LCEA were both measured on the AP hip radiograph.16,18 The Tönnis grade was determined.18,19 Anterior center edge angle (ACEA) was measured in the false-profile radiograph. The LCEA and ACEA was measured from the lateral edge of the bone as previously described.20
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Surgical Technique Revision arthroscopic hip surgery was performed with the patient under general anesthesia in the supine position on a standard traction table. The central compartment was accessed through the anterolateral and modified anterior portals. An interportal capsulotomy was performed as needed based on the amount of residual capsule present, from approximately 12 o’clock to 2 o’clock (Fig 3). A diagnostic arthroscopy was then performed with inspection of the labrum, chondral surfaces, acetabular rim, and remaining capsule. Associated pathology was treated as indicated. Next, traction was released, and the peripheral compartment inspected. All patients underwent a Tcapsulotomy above the zona orbicularis through the distal anterolateral accessory portal to enable appropriate femoral neck visualization for femoral osteochondroplasty. A suture-passing device (SlingShot Suture Manager; Stryker, Greenwood Village, CO) was used to reflect the capsule using a No. 2 highemolecular weight polyethylene sutures in the medial leaflet of the IFL and another in the lateral leaflet of the IFL. Both stitches were retrieved out of the anterolateral portal and tensioned with a hemostat against the skin. With the capsule reflected, any necessary osteochondroplasty of residual cam deformity was performed with excellent visualization of the peripheral compartment. Dynamic examination and fluoroscopic imaging were used to confirm that there was no further impingement and that headeneck offset was restored. Then the capsule was more completely inspected. Any adhesions or scar formation between the capsulolabral junction and capsule muscle intervals were lysed and released and mobility assessed. All of the capsular defects were closed by plication as previously described.21 The previously placed suspension stitches were unclamped and used to repair the interportal capsulotomy using the suture-passing device. All 3 stitches were retrieved and left united until after the vertical aspect of the T-capsulotomy is closed. Based on
Fig 3. Intra-articular arthroscopic images of the central compartment in a right hip demonstrates capsular incompetency. In both intra-articular arthroscopic images, the labrum (L), capsule (C), and femoral head (F) is visualized. In the image on the right, a probe is placed through the defect to point out the defect.
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Table 1. Postoperative Rehabilitation Protocol for Patients With FAIS Phase 1
Goal Protect the joint
Restrictions 20-lb foot-flat weight-bearing at 3 weeks Limit flexion, abduction, extension at 3 wk No active sitting greater than 30 min at 3 wk Work to avoid compensatory or gait
2
Noncompensatory gait progression and active ROM
3
Return to preinjury function
Avoid agility drills until week 10 Avoid hip rotational activities until week 10
4.
Return to sport
Muscle strength and full range of motion goals at week 12.
Techniques Soft-tissue mobilization Isometrics Joint mobilization Gait training Core strengthening/lumbar stabilization Scar mobilization Lumbar stabilization Elliptical at week 6 Single-leg squat Soft-tissue and joint mobilization Core strengthening Joint mobilization Gait training Soft-tissue and joint mobilizations Cardio, strength exercises Agility training Plyometrics Slow progression to return to presurgery level
FAIS, femoroacetabular impingement syndrome; ROM, range of motion.
the senior author’s experience, it is more difficult to pass stitches in the interportal cut after the vertical aspect is closed; therefore, we recommend passing these stitches but not tying until after the vertical capsulotomy is closed. The vertical T-limb of the T-capsulotomy is then closed, beginning at the base of the IFL using suture passing device loaded with a No. 2 highemolecular weight polyethylene suture. The suture passing device loaded with suture is inserted through the cannula in the distal anterolateral accessory portal and a full-thickness pass is made through the medial limb of the T-capsulotomy. The unloaded suture passing device is then reinserted through the distal anterolateral accessory portal, and a larger bite is then made through the lateral limb of the vertical portion at the base of the T-capsulotomy to retrieve the suture and passed it through the medial leaflet. The degree of leaflet overlap in the capsular plication performed depends on the degree of capsular laxity and dynamic intraoperative range of motion. A standard arthroscopic knot is then tied under direct visualization and cut. These steps are then repeated, and 2 more sutures are passed in the vertical portion of the T-capsulotomy. Depending on the size of the incision and integrity of the capsule, the vertical Tlimb is typically closed with 2 to 4 sutures. Lastly, the interportal limb of the T-capsulotomy was untagged, tied, and cut under direct visualization. Postoperative Rehabilitation Rehabilitation started on postoperative day 1 for all patients as previously described and did not differ from therapy indicated for primary FAIS cases.22,23 Patients went through a 4-phase rehabilitation protocol that lasted an average of 16-18 weeks (Table 1).
Functional Outcome Evaluation Before surgery, patient demographics were collected, including sex, age, operative extremity, BMI, sports participation, reason for primary surgery, duration from onset of symptoms to primary surgery, and comorbidities. Range of motion was measured with a goniometer. Patient-reported outcomes obtained preoperatively and at 2-year follow up included the Hip Outcome Score (HOS)dActivities of Daily Living (ADL), HOSdSports Subscale (SS), Modified Harris Hip Score (mHHS), and visual analog scales (VAS) for pain and satisfaction.24 To determine whether there was a difference in meaningful outcome improvement in the patients undergoing revision hip arthroscopy due to capsular incompetency, the minimal clinically important difference (MCID) was calculated. Similar to previous reports in the literature, a distribution based MCID was determined by calculating the ½ standard deviation of the HOS-ADL, HOS-SS, and mHHS in the study patients.25-32 Statistical Analysis Statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics for Windows, Version 22.0; IBM Corp., Armonk, NY). Continuous variables were presented as means with standard deviations. Paired t tests were used to compare preoperative with postoperative changes in patient-reported outcome scores. A c2 analysis was performed to analyze differences in categorical patient characteristics and achieving MCID among the different study groups. Categorical variables were presented as frequencies and percentages. A Tukey post-hoc analysis was used to
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OUTCOMES AFTER REVISION DUE TO CAPSULAR INSUFFICIENCY Table 2. Demographics of Patients Capsular With Incompetency Demographics Total Age, y* BMI* Sex Male Female Operative limb Left Right Procedures Isolated capsular management Labral repair Labral reconstruction Cam resection Microfracture
N/Mean 49 30.0 10.5 25.7 5.5 10 (20.4%) 39 (79.6%) 31 (63.3%) 18 (36.7%) 19 18 2 27 4
(38.8%) (36.7%) (4.1%) (55.1%) (8.2%)
BMI, body mass index. *Reported as mean standard deviation.
compare postoperative outcomes between cohorts. Finally, to control for between-group effects for postoperative patient-reported outcomes, a post-hoc analysis was performed to validate findings from the unmatched analysis. Statistical significance was set at a ¼ 0.05.
Results Baseline Characteristics Of the 90 patients reviewed who underwent revision hip arthroscopy, 49 patients had MRI and intraoperative evidence of a capsular incompetency. Of those, 40 (81.6%) completed 2-year follow up reported outcomes at with a mean time of 25 3.5 months. The majority of these patients were female (79.6%), had a mean age of 30 10.5 years, and had a BMI of 25.7 5.5 (Table 2). Two (4.1%) of the 49 patients with capsular incompetency had the primary surgery performed by the senior author, both of whom underwent partial capsular closure of the vertical portion of the T-capsulotomy. Table 3. Analysis of Pre- and Postoperative Radiographic Parameters Alpha angle (AP) Alpha angle (FP) Alpha angle (Dunn) LCEA ACEA Tönnis angle Tönnis grade 0 1
Preoperative 61.9 19.9 53.9 15.1 57.0 16.0 30.7 5.7 31.7 5.3 7.9 4.1
Postoperative 44.6 10.9 41.8 5.7 39.3 6.4 29.3 5.7 28.7 5.4 9.9 5.7
P Value <.001 <.001 <.001 .275 .014 .051
37 (92.5%) 3 (7.5%)
ACEA, anterior center edge angle; AP, anteroposterior; FP, false profile; LCEA, lateral center edge angle.
Of the 40 patients with 2-year follow up who underwent revision hip arthroscopy for capsular incompetency, 19 of those only required revision surgery for capsular management (debridement of capsular adhesions and capsular closure or capsular reconstruction). In total, 21 of the patients with capsular incompetency had concomitant cam impingement, with 18 having a labral re-tear that required repair. A total of 5 patients had acetabular chondromalacia, with only 1 having grade IV chondromalacia. Of note, 24 (48.9%) had no evidence of capsular closure during their index surgery. Radiographic Parameters Pre- and postoperative radiographic parameters, including the analysis comparing each, are described in Table 3. In brief, there was a statistically significant difference between pre- and postoperative alpha angle averages in each radiographic view (P < .001 for all). Although there was no significant difference in preand postoperative LCEA (30.7 5.7 vs 29.3 5.7; P ¼ .275) or Tönnis angle averages (7.9 4.1 vs 9.9 5.7; P ¼ .051), there was a statistically significant difference in ACEA averages (31.7 5.3 vs 28.7 5.4; P ¼ .014). Of note, there were no patients with hip dysplasia as defined by LCEA or ACEA <20 . Functional Outcomes Preoperatively, the averages for the HOS-ADL, HOSSS, and mHHS were 64.7 19.7, 35.5 28.1, and 51.6 21.0, respectively. Postoperatively, these averages were 77.8 23.3, 57.0 31.6, and 71.9 22.3, respectively. The differences among pre- and postoperative HOS-ADL, HOS-SS, and mHHS were all statistically significant (P < .001). There was also a statistically significant decrease in the VAS pain score (72.8 14.5 vs 27.9 23.0; P < .001) (Table 4). Subanalysis of pre- and postoperative outcomes among revision patients undergoing revision solely due to capsular incompetency versus those with capsular incompetency and concomitant pathology did not show any statistically significant difference (Table 5).
Table 4. Patient-Reported Outcome Measures at a Minimum of 2 Years’ Postoperatively Relative to Preoperative Baseline Scores Preoperative Outcome HOS-ADL HOS-SS mHHS VAS pain VAS satisfaction
64.7 35.5 51.6 72.8
e
19.7 28.1 21.0 14.5
Postoperative
P Value
<.001 <.001 <.001 <.001 e
77.8 57.0 71.9 27.9 73.4
23.3 31.6 22.3 23.0 37.9
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score; VAS, visual analog scale.
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Table 5. Comparison of Pre- and Postoperative Outcomes in Patients With Capsular Incompetency Alone Versus Patients With Other Concomitant Pathology
Preoperative HOS-ADL HOS-SS mHHS VAS pain Postoperative HOS-ADL HOS-SS mHHS VAS pain VAS satisfaction
Revision due to Capsular Incompetency þ Concomitant Pathology e 68.1 17.4 46.47 26.6 60.6 12.1 73.6 13.0 e 78.6 19.5 61.6 29.6 73.3 25.1 25.5 25.3 69.8 36.0
Revision due to Capsular Incompetency e 65.6 16.9 39.1 20.2 58.2 13.3 72.5 14.2 e 76.9 16.2 54.8 29.5 69.2 17.3 31.2 24.3 70.8 36.5
P Value e .767 .126 .404 .528 e .831 .214 .383 .279 .912
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score; VAS, visual analog scale.
Match-Paired Analysis A one-way analysis of variance revealed sufficient matching based off of baseline demographic characteristics. There were no statistically significant differences among the 3 cohorts when comparing preoperative patient-reported outcome measures (Table 6). However, patients who underwent primary hip arthroscopy had significantly superior postoperative outcomes than both revision cohorts. Furthermore, the post-hoc
Table 6. One-way Analysis of Variance for Match-Paired Cohorts Capsular Other Revision Incompetency Causes No./mean Overall 40 Demographics Age 32.4 10.6 BMI 26.14 5.6 Female sex 31 (77.5%) Preoperative HOS-ADL 64.7 19.7 HOS-SS 42.1 27.4 mHHS 59.2 16.5 Pain 72.8 14.5 Postoperative HOS-ADL 77.8 23.3 HOS-SS 57.0 31.6 mHHS 71.9 25.5 Pain 27.9 23.0 satisfaction 70.2 16.3
Primary Cases
No./mean 41
No./mean 40
P Value
33.1 12.3 22.4 8.6 27 (65.9%)
32.3 10.1 25.4 3.9 26 (65%)
.822 .453 .418
60.3 34.7 52.9 73.4
15.9 24.2 17.1 13.9
69.5 43.8 60.4 6.5
15.2 20.8 14.6 1.7
.086 .349 .263 .226
74.7 52.3 64.7 30.9 73.4
23.2 31.9 22.8 28.0 37.9
92.8 83.4 83.9 16.2 82.6
7.7 16.8 12.9 20.4 21.3
<.001 <.001 <.001 <.001 .001
NOTE. Boldface indicates statistical significance. BMI, body mass index; HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; mHHS, Modified Harris Hip Score.
Table 7. MCID Rates for Patients With Capsular Incompetency Versus Patients Undergoing Revision for Other Causes
HOS-ADL HOS-SS mHHS Any MCID threshold achieved
Revisions due to Capsular Incompetency 55.6% 37.5% 52.2% 69.7%
Other Revision Causes 60% 52.2% 52.4% 73.1%
P Value .730 .312 .989 .589
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; MCID, minimal clinically important difference; mHHS, Modified Harris Hip Score.
analysis confirmed the finding from the unmatched analysis that there were no statistically significant differences in postoperative patient-reported outcomes between the 3 revision cohorts. MCID Analysis The MCID threshold values for HOS-ADL, HOS-SS, and mHHS specific to the study group with capsular incompetency were 13.6, 16.8, and 11.2, respectively. The change in 2-year patient-reported outcomes for achieving MCID scores in the non-BHD group were 13.1, 17.1, and 11.2, respectively. c2 analysis demonstrated that there was no statistically significant difference between the frequency of patients achieving MCID in both groups (Table 7). The MCID threshold values for HOS-ADL, HOS-SS, and mHHS specific to the matched study group undergoing primary repair were 8.0, 13.3, and 9.4, respectively. c2 analysis demonstrated that patients undergoing primary hip arthroscopy had greater frequency of achieving MCID for all patient-reported outcomes when compared with patients undergoing revisions for capsular incompetency (Table 8). Complications and Reoperations A total of 2 patients (4.1%) developed postoperative complications and 1 patient (2.0%) required a reoperation. One complication included persistent mechanical Table 8. MCID Rates for Patients With Capsular Incompetency Versus Patients Undergoing Primary Hip Arthroscopy
HOS-ADL HOS-SS mHHS Any MCID threshold achieved
Revisions due to Primary Capsular Incompetency Cases P Value 55.6% 88.2% <.001 37.5% 91.4% <.001 52.2% 73.0% <.001 69.7% 89.9% <.001
HOS-ADL, Hip Outcome ScoredActivities of Daily Living; HOS-SS, Hip Outcome ScoredSports Subscale; MCID, minimal clinically important difference; mHHS, Modified Harris Hip Score.
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symptoms, and the second was due to development of a peripheral neuropathy of the ipsilateral operative limb that subsequently resolved. One revision surgery was performed within 2 years due to mechanical symptoms and persistent pain following a contact sport injury. Intraoperative findings demonstrated continued capsular incompetency requiring capsular reconstruction with a dermal allograft (ArthroFlex; Arthrex, Napes, FL) augmentation as previously described.33 This represents the only patient in this series who underwent capsular reconstruction.
Discussion The main findings of this study were that revision hip arthroscopy with capsular repair for capsular incompetency resulted in significantly improved 2-year postoperative patient-reported outcomes and achieved MCID at similar rates comparable with patients undergoing revisions without capsular incompetency. However, patients undergoing revision for capsular incompetency have significantly lower 2-year patientreported outcome averages and achieve MCID and lower rates than matched patients undergoing primary hip arthroscopy. In addition, we also found that more than one half (54.4%) of hip arthroscopy patients undergoing revision surgery had evidence of a capsular incompetency on preoperative imaging and at the time of revision surgery. Revision hip arthroscopy is a complex, multifactorial decision that requires a thorough understanding of the etiologies of failure. Some of the factors that must be considered include capsular status, presence of dysplasia, and femoral anteversion, among others. Recent literature has reported success with periacetabular osteotomy following failed hip arthroscopy, and this operation must be considered in the presence of dysplasia.34 Nonetheless, increasing evidence continues to demonstrate that microinstability exists even without dysplasia.35 Therefore, in the current study, we attempted to isolate patients with a structurally incompetent capsule without significant dysplasia who underwent revision arthroscopy and sought to compare clinical outcomes with patients with intact capsules. Over the past couple of years, there has been a shift in the orthopaedic literature toward identifying postsurgical meaningful improvement rather than statistical improvement.25,28-32,36 In this study, the MCID was identified for both patients undergoing revisions for capsular incompetency and for those without using the ½ standard deviation of the change in functional scores over a 2-year period.37,38 Previous literature has demonstrated that meaningful clinical threshold values vary based on disease.37,38 Although the MCID values of patient undergoing revision surgery with and without capsular incompetency were not identical, the difference was very modest and not statistically
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significant. This further provides evidence that patients undergoing revisions for capsular incompetency can achieve similar clinical improvements when compared with revision patients without capsular incompetency. Atraumatic instability following hip arthroscopy is a challenging and likely underrecognized complication of hip arthroscopy that has gained increasing attention in the recent literature.1,3,7,10 Although the most common indication for revision hip arthroscopy remains residual FAI, the current study found that capsular incompetency may be a component of more than one half of the revision surgeries performed by a high-volume, fellowship-trained surgeon.39-42 The mechanism by which capsular incompetency and instability can lead to revision surgery has been previously established. Biomechanical studies have shown that capsulotomy at the time of hip arthroscopy increases motion of the hip in multiple planes, placing increasing stress on the labrum as a secondary stabilizer.43,44 Thus, patients with subtle microinstability due to capsular incompetency may present with recurrent labral tears and failure to improve after primary surgery. Despite the increasing acceptance and awareness of both microinstability and capsular incompetency in hip arthroscopy, the detection of such pathology remains challenging, especially in the absence of bony abnormalities or a connective tissue disorder.35 Recent literature has described 6 specific maneuvers to help evaluate hip stability: the anterior apprehension test, abductioneextensioneexternal rotation test, prone external rotation test, log roll test, axial distraction test, and the posterior apprehension test.35 Although these signs may be present and microinstability may exist, it is difficult to determine whether the presence of capsular competence can equal cause for such instability. In the current study, it is likely that many patients were experiencing components of both microinstability and capsular incompetency, resulting in their failure to improve. Previous studies have demonstrated that evidence of capsular closure is observed in both patients with capsular repair and leaving the capsule intact after interportal capsulotomy. Using MRI, Strickland et al.45 compared 15 hips with capsular closure of interportal capsulotomies with 15 with the capsule intact and demonstrated that both demonstrated healing with a contiguous appearance at 24 weeks after surgery. The limitations of radiographic studies such as this include the underpowered analysis caused by a small number of patients in the study group, and based their findings on radiographic evidence that is unable to capture capsular adhesions and small capsular incompetency that can cause refractory pain.46 Moreover, the impact of radiographic studies such as this is limited by not factoring patient clinical function and outcome. Our study demonstrates that patients undergoing revision
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arthroscopy with both isolated cases of capsular incompetency and concomitant pathology have similar improvement in function compared with patients without capsular incompetency undergoing revision surgery. In recent years, closure continues to gain popularity following primary arthroscopic hip surgery, and evidence on outcomes of revision hip arthroscopy secondary due to capsular incompetency has continued to grow as well. Frank et al.47 demonstrated that patients with complete capsular closure report greater HOS-SS values at 2 years compared with patients with an unrepaired interportal capsulotomy. Wylie et al.1 reviewed a cohort of 1100 patients who underwent primary hip arthroscopy and identified 33 who developed postoperative symptomatic instability due to capsular incompetency requiring revision surgery. Similar to the present study, revision surgery consisted of addressing the untreated bony or labral lesions and capsular repair with nonabsorbable suture. Of these patients, 11 had a minimum 2year follow-up. The group reported significantly improved mHHS, HOS-ADL, and HOS-SS outcome scores following revision capsular closure. Larson et al.41 studied their own cohort of revision hip arthroscopy patients and identified 23 hips (27%) with previous unrepaired capsulotomies. Although the group did not isolate this subset of patients, they reported that capsular closure was an independent predictor of improved outcomes after revision surgery. The present study adds valuable data and insight to revision surgery for capsular incompetency. Our study is one of the largest in the literature to specifically look at revision hip arthroscopy for capsular repair in patients with persistent pain and a capsular incompetency on both preoperative MRI and at the time of surgery. With all patients demonstrating significant postoperative improvements compared with preoperative baseline scores, we further highlight the importance of capsular management and closure. To better understand the effects of capsular repair, we furthered our analysis by comparing our study cohort with revision patients without capsular incompetency and patients undergoing primary surgery. With appropriate capsular management in a revision setting, patients with capsular incompetency can expect similar outcomes at 2 years as their counterparts undergoing revision surgery with an intact, healed capsule. However, as has been previously established, outcomes following revision hip arthroscopy will not produce clinical outcomes equivalent to that of primary hip arthroscopy patients, regardless of capsular integrity at the time of revision surgery. Limitations There are several limitations to the current study. First, an a priori analysis was not performed, and
therefore an effect size has not been established for any variable to calculate the necessary population size for observed power of >0.8. A post-hoc power analysis in this study is dependent on what comparison is chosen to calculate the effect size for determining the observed power. When using the postoperative HOS-ADL score of primary cases and revisions due to capsular defect, the effect size (Cohen’s d) is equal to 0.89086, and the observed power for a 2-tailed hypothesis is 0.992. If the pre- and postoperative HOS-ADL scores for patients undergoing revisions for capsular deficiency were used, the effect size (Cohen’s d) is equal to 0.60.717, and the observed power for a 2-tailed hypothesis is 0.844. However, these power analyses may not be applicable to all the t tests performed in this study, and it may be possible that some of the analysis is underpowered. Second, the number of patients with isolated capsular incompetency undergoing capsular repair was relatively small, and we had to combine them with patients undergoing revision for capsular incompetency and other concomitant pathology for the main analysis of the study including calculation of MCID. In addition, given the limited number of patients available to study, we were unable to exactly sex-match. Although the groups were statistically similar in female predominance, they were not exactly sex-matched, and this may influence our results. Third, although the revision cohort studied showed capsular incompetency on MRI, there was also residual impingement in a large percentage of patients. Although it is beyond the scope of the current study to distinguish whether capsular incompetency or residual impingement resulted in the failure to improve following their primary surgery, the 2 are likely interrelated and each must be considered and treated at the time of revision surgery to improve patient outcomes. Finally, although all of the revision patients had complete capsular management including capsular closure, some required capsular reconstruction due to significant incompetency, whereas most were able to be closed primarily. Unfortunately, the numbers of patients with capsular reconstruction were not enough to compare outcomes with patients who underwent primary closure. This is a substantially greater degree of surgery and one might expect inferior outcomes in these patients, thus skewing our results.
Conclusions More than one half of patients undergoing revision hip arthroscopy had MRI and intraoperative evidence of capsular incompetency. Revision arthroscopy for capsular incompetency results in significantly improved 2-year outcomes. However, patients undergoing revision for capsular incompetency and intact capsule revision patients reported significantly lower outcomes compared with primary patients.
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References 1. Wylie JD, Beckmann JT, Maak TG, Aoki SK. Arthroscopic capsular repair for symptomatic hip instability after previous hip arthroscopic surgery. Am J Sports Med 2016;44: 39-45. 2. Cvetanovich GL, Weber AE, Kuhns BD, et al. Hip Arthroscopic surgery for femoroacetabular impingement with capsular management: Factors associated with achieving clinically significant outcomes. Am J Sports Med 2018;46:288-296. 3. Domb BG, Philippon MJ, Giordano BD. Arthroscopic capsulotomy, capsular repair, and capsular plication of the hip: Relation to atraumatic instability. Arthroscopy 2013;29:162-173. 4. McCormick F, Slikker W 3rd, Harris JD, et al. Evidence of capsular defect following hip arthroscopy. Knee Surg Sports Traumatol Arthrosc 2014;22:902-905. 5. Benali Y, Katthagen BD. Hip subluxation as a complication of arthroscopic debridement. Arthroscopy 2009;25: 405-407. 6. Mei-Dan O, McConkey MO, Brick M. Catastrophic failure of hip arthroscopy due to iatrogenic instability: Can partial division of the ligamentum teres and iliofemoral ligament cause subluxation? Arthroscopy 2012;28:440-445. 7. Philippon MJ, Schenker ML, Briggs KK, Kuppersmith DA, Maxwell RB, Stubbs AJ. Revision hip arthroscopy. Am J Sports Med 2007;35:1918-1921. 8. Bowman KF Jr, Fox J, Sekiya JK. A clinically relevant review of hip biomechanics. Arthroscopy 2010;26: 1118-1129. 9. Smith KM, Gerrie BJ, McCulloch PC, et al. Arthroscopic hip preservation surgery practice patterns: An international survey. J Hip Preserv Surg 2017;4:18-29. 10. Ortiz-Declet V, Mu B, Chen AW, et al. Should the capsule be repaired or plicated after hip arthroscopy for labral tears associated with femoroacetabular impingement or instability? A systematic review. Arthroscopy 2018;34: 303-318. 11. Westermann RW, Bessette MC, Lynch TS, Rosneck J. Does closure of the capsule impact outcomes in hip arthroscopy? A systematic review of comparative studies. Iowa Orthop J 2018;38:93-99. 12. Chahla J, Mikula JD, Schon JM, et al. Hip capsular closure: A biomechanical analysis of failure torque. Am J Sports Med 2017;45:434-439. 13. Bolia I, Chahla J, Locks R, Briggs K, Philippon MJ. Microinstability of the hip: A previously unrecognized pathology. Muscles Ligaments Tendons J 2016;6:354-360. 14. Griffin DR, Dickenson EJ, O’Donnell J, et al. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): An international consensus statement. Br J Sports Med 2016;50:1169-1176. 15. Weber AE, Jacobson JA, Bedi A. A review of imaging modalities for the hip. Curr Rev Musculoskelet Med 2013;6: 226-234. 16. Clohisy JC, Carlisle JC, Beaule PE, et al. A systematic approach to the plain radiographic evaluation of the young adult hip. J Bone Joint Surg Am 2008;90:47-66 (suppl 4). 17. Notzli HP, Wyss TF, Stoecklin CH, Schmid MR, Treiber K, Hodler J. The contour of the femoral head-neck junction
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
135
as a predictor for the risk of anterior impingement. J Bone Joint Surg Br 2002;84:556-560. Krych AJ, Thompson M, Knutson Z, Scoon J, Coleman SH. Arthroscopic labral repair versus selective labral debridement in female patients with femoroacetabular impingement: A prospective randomized study. Arthroscopy 2013;29:46-53. Tonnis D, Heinecke A, Nienhaus R, Thiele J. [Predetermination of arthrosis, pain and limitation of movement in congenital hip dysplasia (author’s transl)]. Z Orthop Ihre Grenzgeb 1979;117:808-815. Sakai T, Nishii T, Sugamoto K, Yoshikawa H, Sugano N. Is vertical-center-anterior angle equivalent to anterior coverage of the hip? Clin Orthop Relat Res 2009;467:2865-2871. Levy DM, Grzybowski J, Salata MJ, Mather RC, Aoki SK, Nho SJ. Capsular plication for treatment of iatrogenic hip instability. Arthrosc Tech 2015;4:e625-e630. Malloy P, Gray K, Wolff AB. Rehabilitation after hip arthroscopy: A movement control-based perspective. Clin Sports Med 2016;35:503-521. Leong NL, Clapp IM, Neal WH, Beck E, Bush-Joseph CA, Nho SJ. The influence of pain in other major joints and the spine on 2-year outcomes after hip arthroscopy. Arthroscopy 2018;34:3196-3201. Martin RL, Philippon MJ. Evidence of reliability and responsiveness for the hip outcome score. Arthroscopy 2008;24:676-682. Nwachukwu BU, Fields K, Chang B, Nawabi DH, Kelly BT, Ranawat AS. Preoperative outcome scores are predictive of achieving the minimal clinically important difference after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2017;45:612-619. Levy DM, Cvetanovich GL, Kuhns BD, Greenberg MJ, Alter JM, Nho SJ. Hip arthroscopy for atypical posterior hip pain: A comparative matched-pair analysis. Am J Sports Med 2017;45:1627-1632. Katz NP, Paillard FC, Ekman E. Determining the clinical importance of treatment benefits for interventions for painful orthopedic conditions. J Orthop Surg Res 2015;10:24. Nwachukwu BU, Chang B, Adjei J, et al. Time required to achieve minimal clinically important difference and substantial clinical benefit after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2018;46: 2601-2606. Nwachukwu BU, Chang B, Fields K, et al. Defining the "substantial clinical benefit" after arthroscopic treatment of femoroacetabular impingement. Am J Sports Med 2017;45:1297-1303. Nwachukwu BU, Chang B, Kahlenberg CA, et al. Arthroscopic treatment of femoroacetabular impingement in adolescents provides clinically significant outcome improvement. Arthroscopy 2017;33:1812-1818. Nwachukwu BU, Chang B, Voleti PB, et al. Preoperative short form health survey score is predictive of return to play and minimal clinically important difference at a minimum 2-year follow-up after anterior cruciate ligament reconstruction. Am J Sports Med 2017;45:2784-2790. Nwachukwu BU, Chang B, Beck EC, et al. How should we define clinically significant outcome improvement on the iHOT-12? HSS J 2019;15:103-108.
136
J. M. CANCIENNE ET AL.
33. Chahla J, Dean CS, Soares E, Mook WR, Philippon MJ. Hip capsular reconstruction using dermal allograft. Arthrosc Tech 2016;5:e365-e369. 34. Novais EN, Coobs BR, Nepple JJ, Clohisy JC, Group AS. Previous failed hip arthroscopy negatively impacts early patient-reported outcomes of the periacetabular osteotomy: An ANCHOR Matched Cohort Study. J Hip Preserv Surg 2018;5:370-377. 35. Safran MR. Microinstability of the hipdgaining acceptance. J Am Acad Orthop Surg 2019;27:12-22. 36. Cvetanovich GL, Weber AE, Kuhns BD, et al. Clinically meaningful improvements after hip arthroscopy for femoroacetabular impingement in adolescent and young adult patients regardless of gender. J Pediatr Orthop 2018;38:465-470. 37. Leopold SS. Editor’s spotlight/take 5: Comparative responsiveness and minimal clinically important differences for idiopathic ulnar impaction syndrome. Clin Orthop Relat Res 2013;471:1403-1405. 38. Kosinski M, Zhao SZ, Dedhiya S, Osterhaus JT, Ware JE Jr. Determining minimally important changes in generic and disease-specific health-related quality of life questionnaires in clinical trials of rheumatoid arthritis. Arthritis Rheum 2000;43:1478-1487. 39. Ross JR, Larson CM, Adeoye O, Kelly BT, Bedi A. Residual deformity is the most common reason for revision hip arthroscopy: A three-dimensional CT study. Clin Orthop Relat Res 2015;473:1388-1395. 40. Sardana V, Philippon MJ, de Sa D, et al. Revision hip arthroscopy indications and outcomes: A systematic review. Arthroscopy 2015;31:2047-2055.
41. Larson CM, Giveans MR, Samuelson KM, Stone RM, Bedi A. Arthroscopic hip revision surgery for residual femoroacetabular impingement (FAI): Surgical outcomes compared with a matched cohort after primary arthroscopic FAI correction. Am J Sports Med 2014;42: 1785-1790. 42. Bogunovic L, Gottlieb M, Pashos G, Baca G, Clohisy JC. Why do hip arthroscopy procedures fail? Clin Orthop Relat Res 2013;471:2523-2529. 43. Bayne CO, Stanley R, Simon P, et al. Effect of capsulotomy on hip stability-a consideration during hip arthroscopy. Am J Orthop (Belle Mead NJ) 2014;43: 160-165. 44. Myers CA, Register BC, Lertwanich P, et al. Role of the acetabular labrum and the iliofemoral ligament in hip stability: an in vitro biplane fluoroscopy study. Am J Sports Med 2011;39:85S-91S (suppl). 45. Strickland CD, Kraeutler MJ, Brick MJ, et al. MRI evaluation of repaired versus unrepaired interportal capsulotomy in simultaneous bilateral hip arthroscopy: A double-blind, randomized controlled trial. J Bone Joint Surg Am 2018;100:91-98. 46. Shin JJ, de Sa DL, Burnham JM, Mauro CS. Refractory pain following hip arthroscopy: Evaluation and management. J Hip Preserv Surg 2018;5:3-14. 47. Frank RM, Lee S, Bush-Joseph CA, Kelly BT, Salata MJ, Nho SJ. Improved outcomes after hip arthroscopic surgery in patients undergoing T-capsulotomy with complete repair versus partial repair for femoroacetabular impingement: A comparative matched-pair analysis. Am J Sports Med 2014;42:2634-2642.