- Email: [email protected]
Preoperative Duration of Symptoms Is Associated With Outcomes 5 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome
Preoperative Duration of Symptoms Is Associated With Outcomes 5 Years After Hip Arthroscopy for Femoroacetabular Impingement Syndrome Kyle N. Kunze, B.S., Benedict U. Nwachukwu, M.D., M.B.A., Edward C. Beck, M.D., M.P.H., Jorge Chahla, M.D., Ph.D., Anirudh K. Gowd, M.D., Jonathan Rasio, B.S., and Shane J. Nho, M.D., M.S.
Purpose: To determine the effect of the preoperative duration of femoroacetabular impingement syndrome (FAIS)e associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy. Methods: We identified FAIS patients who underwent primary hip arthroscopy between January 2012 and January 2014 with a minimum of 5 years’ follow-up. Patient demographic characteristics and clinical outcomes, comprising the Hip Outcome ScoreeActivities of Daily Living (HOS-ADL), Hip Outcome ScoreeSports Subscale (HOS-SS), modified Harris Hip Score (mHHS), pain score, and satisfaction score, were analyzed. The minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit were calculated. Patients were stratified based on the preoperative duration of symptoms: less than 2 years versus 2 years or longer. Multivariate regressions were constructed to determine the association between the preoperative symptom duration and clinical outcomes at 5 years after hip arthroscopy. Results: A total of 310 patients were included with a mean age (standard deviation) of 34.1 11.9 years and body mass index of 25.3 5.1. The study group showed statistically significant improvements in the HOS-ADL, HOS-SS, mHHS, pain score, and satisfaction score (P < .001 for all). A preoperative duration of symptoms of 2 or more years was an independent predictor of worse HOS-ADL, HOS-SS, mHHS, and pain score (P < .05 for all). Furthermore, a longer duration of symptoms was associated with a lower likelihood of achieving the minimal clinically important difference for the HOSADL (odds ratio [OR], 0.53; P ¼ .037), HOS-SS (OR, 0.38; P ¼ .003), and mHHS (OR, 0.43; P ¼ .009); the patient acceptable symptomatic state for the HOS-SS (OR, 0.44; P ¼ .006) and mHHS (OR, 0.46; P ¼ .006) but not the HOS-ADL despite trending toward significance (OR, 0.59; P ¼ .098); and substantial clinical benefit for the HOS-ADL (OR, 0.50; P ¼ .011), HOS-SS (OR, 0.52; P ¼ .020), and mHHS (OR, 0.47; P ¼ .007). Conclusions: Patients with a preoperative duration of FAIS-associated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up. Level of Evidence: Level III, retrospective comparative trial.
A
rthroscopic hip-preservation surgery for the treatment of femoroacetabular impingement syndrome (FAIS) is now an increasingly common intervention that has been shown to confer
improvements in functional status and patient-reported pain in multiple contexts.1-7 FAIS has been defined as symptomatic hip pain and dysfunction due to osseous abnormalities of the hip joint. With the adoption of hip
From the Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center (K.N.K., B.U.N., E.C.B., J.C., J.R., S.J.N.), Chicago, Illinois; and Department of Orthopaedic Surgery, Wake Forest School of Medicine (A.K.G.), Winston-Salem, North Carolina, U.S.A. The authors report the following potential conflicts of interest or sources of funding: B.U.N. receives hospitality payments from Stryker, Wright Medical Technology, and Zimmer Biomet. S.J.N. receives research support from Allosource, Arthrex, Athletico, DJ Orthopaedics, Linvatec, Miomed, Smith & Nephew, and Stryker; serves on the editorial/governing board of the American Journal of Orthopedics; is a board/committee member of the American Orthopaedic Society for Sports Medicine and Arthroscopy Association of North America; receives IP royalties from and is a paid consultant for Ossur; and
receives publishing royalties and financial/material support from Springer. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Paper previously presented at: International Society of Hip Arthroscopy Annual Conference, Madrid, Spain, October 17e19, 2019. Received May 8, 2019; accepted August 19, 2019. Address correspondence to Shane J. Nho, M.D., M.S., Department of Orthopaedics, Rush University Medical Center, 1611 W Harrison St, Ste 300, Chicago, IL 60612, U.S.A. E-mail: [email protected] Ó 2019 by the Arthroscopy Association of North America 0749-8063/19584/$36.00 https://doi.org/10.1016/j.arthro.2019.08.032
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol
-,
No
-
(Month), 2019: pp 1-8
1
2
K. N. KUNZE ET AL.
arthroscopy as a common means of treating FAIS, midto long-term outcomes are now being reported, which have reinforced the durability of clinical improvement.8-13 Many clinical variables shown to influence outcomes at 2 years after hip arthroscopy for FAIS have yet to be studied at these longer postoperative intervals, and their effect remains unknown. One such clinical consideration is the duration of FAIS-associated symptoms prior to arthroscopic intervention. Basques et al.14 performed a retrospective cohort study of 624 patients with FAIS and stratified them based on a preoperative duration of symptoms of less than 24 months versus 24 months or longer. They showed that patients who experienced a longer preoperative duration of symptoms had significantly worse patient-reported outcomes and higher rates of reoperation at 2 years than patients with a shorter preoperative symptom duration. Given this clinical significance, it is important to determine whether such a relationship is maintained at longer-term follow-up. The purpose of this study was to determine the effect of the preoperative duration of FAIS-associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy. We hypothesized that patients with a longer duration of symptoms would experience worse clinical outcomes and more pain and would achieve a lower rate of clinically significant outcome improvement at a minimum of 5 years after hip arthroscopy.
Methods Patient Selection This study received institutional review board approval to record and retrospectively analyze the clinical outcomes of patients who underwent hip arthroscopy for FAIS. All patients were treated by the senior author (S.J.N.) at a large, tertiary center dedicated to arthroscopic hip-preservation surgery. All patients undergoing primary hip arthroscopy for the treatment of FAIS between January 1, 2012, and January 31, 2014, were included in this study. The inclusion criteria consisted of a clinical and radiographic diagnosis of symptomatic FAIS,15 failure of conservative management (physical therapy, activity modification, oral anti-inflammatories, and intra-articular cortisone injections), and a minimum of 5 years’ follow-up. The exclusion criteria consisted of patients with congenital hip conditions (slipped capital femoral epiphysis, developmental hip dysplasia, avascular necrosis, and so on), patients undergoing concomitant gluteus medius repairs, patients who underwent prior ipsilateral hip surgery, patients with signs of osteoarthritis (Tönnis grade >1), and patients with hip dysplasia (lateral center-edge angle <20 ). Patients were stratified based on whether they had experienced FAIS-related symptoms for 2 or more years
prior to hip arthroscopy. We chose a 2-year symptom duration because this has been used for stratification previously in the literature on femoroacetabular impingement.14 Related symptoms in both cohorts included primary hip complaints such as hip pain with active and passive range of motion, limitations of daily activities, decreased range of motion, mechanical symptoms, and pain with palpation to osseous structures such as the sacroiliac joint and the pubic symphysis on physical examination. Surgical Technique All hip arthroscopies were performed by a single fellowship-trained hip surgeon (S.J.N.) at a highvolume academic hospital using a technique that has been well described in the literature.16-18 In brief, an interportal capsulotomy was created, and pathology in the central compartment was addressed; the procedures included acetabuloplasty, labral debridement in cases of salvageable labral tissue, or labral repair for significant tears. A vertical T-capsulotomy was performed to address cam pathology in the peripheral compartment. On completion, a dynamic examination of the operative leg was performed to confirm appropriate resolution of impingement. The capsule was then repaired using a suture shuttling system, and plication was performed depending on the degree of capsular laxity. Rehabilitation was started on postoperative day 1 in all patients as previously described.19,20 Clinical Outcome Evaluation Patients completed hip-specific outcome instruments at preoperative visits and at a minimum of 5 years postoperatively. Hip outcome instruments included the Hip Outcome ScoreeActivities of Daily Living (HOSADL),21 Hip Outcome ScoreeSports Subscale (HOSSS),22 modified Harris Hip Score (mHHS),23 visual analog scale (VAS) for pain, and VAS for satisfaction. To determine clinically significant outcome improvement, the minimal clinically important difference (MCID) for the HOS-ADL, HOS-SS, and mHHS was calculated based on one-half of the standard deviation of the entire study cohort for the HOS-ADL, HOS-SS, and mHHS, respectively.24-26 The patient acceptable symptomatic state (PASS)27 and substantial clinical benefit (SCB)28 for the HOS-ADL, HOS-SS, and mHHS were calculated using anchor-based methods and receiver operating characteristic curves. The anchor question for the PASS was as follows: “Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?” The PASS value was then identified using receiver operating characteristic curve analysis as has been shown to be feasible in the literature.27,29 Sensitivity and specificity values of 0.80 were used as the
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME
cutoff values for determining the threshold cutoff scores. SCB was calculated similarly to the PASS using an anchor-based method. Patients were asked the following question: “Since your surgery, has there been any change in your daily functioning and non-sporting activities related to your treated hip?” The available choices were as follows: "a very great deal better," "a great deal better," "a good deal better," "moderately better," "a little better," "somewhat better," "almost the same/hardly any better," "no change," "almost the same/hardly any worse," "somewhat worse," "a little worse," "moderately worse," "a good deal worse," "a great deal worse," and "a very great deal worse." Patients responding "a very great deal better," "a great deal better," or "a good deal better" were classified as the “much improved group,” whereas patients responding “almost the same/hardly any better," "no change," or "almost the same/hardly any worse" were classified as the “no change group.” As shown in previous studies, pain and physical anchor questions are useful for psychometric analysis to identify clinically meaningful improvements in function.28,30,31 As with prior psychometric studies in the orthopaedic literature, an area under the curve greater than 0.8 was considered acceptably predictive.28 Statistical Analysis Continuous variables were presented as means with standard deviations and ranges, whereas categorical variables were presented as frequencies with percentages. Data were analyzed for normality of distribution prior to analysis, and appropriate parametric or nonparametric tests were used to compare variables at baseline. Paired t tests were performed to determine whether mean patient-reported outcome scores significantly differed at latest follow-up relative to preoperative values. Multivariate linear regression models were constructed controlling for age, body mass index (BMI), sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade) to determine statistically significant associations between the preoperative symptom duration and the (1) HOS-ADL (2) HOS-SS, (3) mHHS, (4) VAS pain score, and (5) VAS satisfaction score postoperatively at a minimum of 5 years. Multivariate logistic regression models controlling for the same covariates were performed to determine associations between the preoperative symptom duration and (1) the MCID for the HOS-ADL, HOS-SS, and mHHS; (2) the PASS for the HOS-ADL, HOS-SS, and mHHS; and (3) SCB for the HOS-ADL, HOS-SS, and mHHS at a minimum of 5 years postoperatively. All statistical analyses were performed using Stata software (version 15.1; StataCorp, College Station, TX). Statistical significance was set at P < .05.
3
Results Of the 425 patients for whom the perioperative pain duration was recorded, 310 (79.7%) met the inclusion criteria and were included in the final analysis; a total of 79 patients did not fill out the questionnaire (Fig 1). The study group had a mean age (standard deviation) of 34.1 11.9 years and BMI of 25.3 5.1. Of the 310 patients, 190 (61.3%) were female patients and 198 (63.9%) were involved in sports activity (Table 1). All of the patients included in the study underwent femoroplasty, acetabuloplasty or rim trimming, and capsular closure. The rest of the procedures are summarized in Table 2. The study group showed statistically significant improvements at 5 years after hip arthroscopy in average values for the HOS-ADL (83.7 19.9 vs 67.3 19.6, P < .001), HOS-SS (73.5 28.8 vs 45.9 23.8, P < .001), mHHS (77.3 22.7 vs 58.2 15.6, P < .001), and VAS pain score (74.2 18.6 vs 29.8 29.8, P < .001). Preoperative Symptom Duration and Stratification A total of 120 patients (38.7%) reported experiencing symptoms for a duration of 2 or more years (Table 1). Patients with a duration of preoperative FAIS-related symptoms of 2 or more years were older (P ¼ .014) and had greater BMI values (P ¼ .002) than patients with a shorter duration of symptoms when the 2 cohorts were compared. No significant differences in patient-reported outcome measures were found preoperatively; however, patients with FAIS-associated symptoms for 2 or more years had significantly greater HOS-ADL (88.1 16.5 vs 79.6 21.9, P ¼ .001), HOS-SS (79.1 25.9 vs 65.0 32.2, P < .001), and mHHS (81.3 21.5 vs 72.0 24.7, P ¼ .005) values, as well as a significantly lower VAS pain score (24.8 25.6 vs 34.7 31.1, P ¼ .012), at a minimum of
Fig 1. Flowchart describing patient population in final analysis, including exclusion and inclusion criteria. (FAIS, femoroacetabular impingement syndrome.)
4
K. N. KUNZE ET AL.
Table 1. Baseline Patient Characteristics No. of patients Demographic characteristics Age, yr BMI Female Sports activity Smoking Workers’ Compensation Pain duration, mo Radiographic parameters Alpha angle, LCEA, Tönnis grade 1
Preoperative Symptoms <2 yr 190
Preoperative Symptoms 2 yr 120
All Patients 310
P Value
32.3 12.0 24.5 4.5 115 (60.5) 131 (68.9) 11 (5.8) 14 (7.4) 9.8 5.3
36.2 11.4 26.4 5.8 75 (62.5) 97 (80.8) 14 (11.7) 2 (1.7) 54.7 49.2
34.1 11.9 25.3 5.1 190 (61.3) 198 (63.9) 25 (8.1) 16 (5.2) 27.0 37.6
.014* .002* .89 .52 .07 .06 <.001*
59.2 9.8 33.4 6.8 13 (6.8)
61.9 10.1 33.8 7.6 21 (17.5)
60.7 10.1 33.6 7.1 34 (11)
.81 .61 .07
NOTE. Baseline Characteristics Were Analyzed Using Independent t Tests or the c2 Test of Association When Appropriate. Continuous Variables are Reported as Mean Standard Deviation, Whereas Categorical Variables are Reported as Number (Frequency). BMI, body mass index; LCEA, lateral center-edge angle. *Statistically significant at P < .05 level.
5 years postoperatively (Table 3). No statistically significant difference was found in VAS satisfaction scores. A series of multivariate linear regression models were subsequently constructed controlling for baseline covariates to determine whether symptom duration was independently associated with postoperative outcomes at 5 years. These models indicated that a preoperative symptom duration of 2 or more years was significantly and independently associated with worse HOS-ADL, HOS-SS, mHHS, and VAS pain scores at a minimum of 5 years postoperatively (Table 4). Binary logistic regression models were constructed to determine whether the preoperative symptom duration was predictive of achieving meaningful clinical outcomes as defined by the MCID, PASS, or SCB (Table 5). These analyses revealed that patients with a preoperative symptom duration of 2 or more years were less likely to reach the HOS-ADL (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.29-0.96; P ¼ .037), HOS-SS (OR, 0.38; 95% CI, 0.2-0.72; P ¼ .003), and mHHS (OR, 0.43; 95% CI, 0.23-0.81 P ¼ .009) threshold scores for achieving the MCID. A preoperative symptom duration of 2 or more years was also independently associated with a lower likelihood of reaching the HOS-SS (OR, 0.44; 95% CI, 0.25-0.79;
Table 2. Operative Procedures Acetabuloplasty or rim trimming Femoroplasty Labral repair Labral debridement Excision of os acetabuli Removal of loose body Trochanteric bursectomy Microfracture Capsular closure
n (%) 310 (100) 310 (100) 302 (97.4) 8 (2.6) 2 (0.6) 1 (0.3) 2 (0.6) 1 (0.3) 310 (100)
P ¼ .006) and mHHS (OR, 0.46; 95% CI, 0.27-0.81; P ¼ .006) threshold scores for achieving the PASS. Regarding SCB, patients with a preoperative symptom duration of 2 or more years were less likely to reach the HOS-ADL (OR, 0.50; 95% CI, 0.3-0.86; P ¼ .011), HOSSS (OR, 0.52; 95% CI, 0.3-0.9; P ¼ .020), and mHHS (OR, 0.47; 95% CI, 0.27-0.81; P ¼ .007) threshold scores for achieving SCB. Among the entire cohort of 310 patients, a total of 4 revisions (1.3%) had been performed at 5 years postoperatively. In the cohort with a symptom duration of 2 or more years, there were 2 revisions (1.9%); likewise, in the control cohort, there were 2 revisions (1.2%). In a multivariate logistic regression analysis, the duration of symptoms was not independently associated with revision hip arthroscopy at 5 years (OR, 1.5; 95% CI, 0.22-11.5; P ¼ .64).
Discussion The primary findings of this study were that patients who experienced FAIS-associated symptoms for 2 or more years prior to hip arthroscopy had worse clinical outcomes as determined by inferior HOS-ADL (88.1 vs 79.6), HOS-SS (79.1 vs 65.0), and mHHS (81.3 vs 72.0) values and VAS satisfaction scores (75.3 vs 69.7), as well as more pain (34.8 vs 34.7), at a minimum of 5 years postoperatively. Furthermore, patients who experienced a symptom duration of 2 or more years showed less clinically significant outcome improvement as determined by the lower proportion of MCID, PASS, and SCB achievement by this cohort for the HOS-ADL, HOS-SS, and mHHS. In addition, we found an independent association between a symptom duration of 2 or more years and a lower likelihood of achieving the MCID and SCB for the HOS-ADL, HOS-SS, and mHHS, as well as the PASS for the HOS-SS and mHHS, at 5 years after hip arthroscopy.
5
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME Table 3. Comparison of Preoperative and Postoperative Outcome Scores Between Patient Groups Preoperative Symptom Duration <2 yr Preoperative outcome scores HOS-ADL HOS-SS mHHS VAS pain score 5-yr outcome scores HOS-ADL HOS-SS mHHS VAS pain score VAS satisfaction score
Preoperative Symptom Duration 2 yr
All Patients
P Value
68.9 46.0 58.2 75.2
18.4 23.6 14.3 15.7
65.0 43.4 55.8 71.9
20.7 25.7 16.7 21.0
67.4 45.0 57.3 73.9
19.3 24.4 15.2 18.0
.11 .42 .24 .21
88.1 79.1 81.3 24.8 75.3
16.5 25.9 21.5 25.6 31.3
79.6 65.0 72.0 34.7 69.7
21.9 32.2 24.7 31.1 34.9
84.5 73.1 77.4 28.7 73.1
19.4 29.5 23.3 28.3 32.8
.001* <.001* .005* .012* .2
NOTE. Data are presented as mean standard deviation. HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; mHHS, modified Harris Hip Score; VAS, visual analog scale. *Statistically significant at P < .05 level.
A variety of preoperative clinical variables have been investigated with respect to their potential influence on postoperative outcomes at 5 years after hip arthroscopy for FAIS. Indeed, factors such as the Tönnis grade,8 age,12,32 borderline hip dysplasia,9 concomitant periacetabular osteotomy33 or microfracture,34 femoral head osteochondral lesions,10 and obesity13 have been studied within the context of mid-term outcomes. The evolution of literature seeking to describe the influence of such factors is essential as patients become further removed from arthroscopic intervention and need to be counseled on expectations. Despite the continued identification of prognostic factors, many factors that have been shown to influence short-term outcomes after hip arthroscopy remain poorly understood.
Table 4. Multivariate Linear Regression Model for Influence of Preoperative Duration of FAIS-Associated Symptoms on 5-Year Outcome Scores, With Preoperative Symptom Duration less than 2 Years as Reference Variable Outcome HOS-ADL HOS-SS mHHS VAS pain score VAS satisfaction score
b* e5.5 e12.1 e9.6 9.6 e6.5
95% CI e10.7 to e0.22 e20.7 to e3.6 e16.9 to e2.2 1.3 to 17.9 e16.0 to 3.09
P Value .041y .006y .011y .023y .18
CI, confidence interval; FAIS, femoroacetabular impingement syndrome; HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; mHHS, modified Harris Hip Score; VAS, visual analog scale. *The multivariate linear regression model controlled for age, body mass index, sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade). The b value describes the magnitude of change that the independent effect of symptom duration has on each outcome variable relative to patients with a shorter symptom duration. y Statistically significant at P < .05 level.
Our study examined the influence of the duration of preoperative FAIS-associated symptoms on postoperative outcomes in the medium to long term. A longer duration of preoperative symptoms, specifically 2 or more years prior to hip arthroscopy, is known to predispose patients to worse clinical outcomes and a lower rate of clinically significant outcome improvement at 2 years after hip arthroscopy.14 It appears that this effect persists in the medium to long term. Our study showed that patients with a preoperative duration of symptoms of 2 or more years prior to hip arthroscopy experienced inferior clinical outcomes and persistently greater pain at a minimum of 5 years after hip arthroscopy compared with patients with a shorter duration of symptoms. Despite this finding, it should be noted that symptom duration was a self-reported variable and is inherently subjective, which may introduce bias. Together, these data hold potential clinical implications for prognosticating, counseling patients on expectations, and potentially expediting arthroscopic intervention; however, it is important to acknowledge that basic statistical comparisons of absolute patientreported outcome measures may be subject to confounding. Furthermore, it is often unclear to the treating surgeon and patient how relevant these absolute outcome scores are because they do not necessarily reflect the patient’s perception of his or her improvement. For these reasons, this study performed multivariate logistic regression models that controlled for potential confounding variables, which may influence outcomes, and examined psychometric measures (MCID, PASS, and SCB), which more appropriately indicate the clinical significance of improvement for each patient. Such models minimize statistical bias and provide an inherently more reliable assessment of outcome. The results of these additional analyses indicated that a preoperative symptom duration of 2 or more years was a risk factor for
6
K. N. KUNZE ET AL.
Table 5. Multivariate Logistic Regression Model for Influence of Preoperative Duration of FAIS-Associated Symptoms on 5-Year Rates of Clinically Significant Outcome Improvement, With Preoperative Symptom Duration less than 2 Years as Reference Variable
Outcome MCID HOS-ADL HOS-SS mHHS PASS HOS-ADL HOS-SS mHHS SCB HOS-ADL HOS-SS mHHS
Multivariate Logistic Regression*
Preoperative Symptom Duration <2 yr, n (%)
Preoperative Symptom Duration 2 yr, n (%)
All Patients, n (%)
OR
P Value
144 (75.8) 152 (80.0) 154 (81.1)
80 (66.7) 84 (70.0) 87 (72.5)
224 (72.3) 236 (76.1) 241 (77.7)
0.53 0.38 0.43
.037y .003y .009y
145 (76.3) 138 (72.6) 125 (65.8)
81 (67.5) 75 (62.5) 65 (54.2)
226 (72.9) 213 (68.7) 190 (61.3)
0.59 0.44 0.46
.098 .006y .006y
105 (55.2) 130 (68.4) 114 (60.0)
52 (43.3) 71 (59.2) 58 (48.3)
157 (50.6) 201 (64.8) 172 (55.5)
0.50 0.52 0.47
.011y .020y .007y
FAIS, femoroacetabular impingement syndrome; HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; MCID, minimal clinically important difference; mHHS, modified Harris Hip Score; OR, odds ratio; PASS, patient acceptable symptomatic state; SCB, substantial clinical benefit. *Multivariate logistic regression model controlling for age, body mass index, sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade). y Statistically significant at P < .05 level.
less frequent clinically significant outcome improvement in terms of the MCID, PASS, and SCB; this finding is in accordance with the findings of a short-term study performed by Basques et al.14 Specifically, a symptom duration of 2 or more years portended a lower likelihood for all included psychometric measures with the exception of the PASS for the HOS-ADL, suggesting that this aspect of a patient’s history holds significant clinical implications. It is possible that compensatory changes to the symptomatic hip and subsequent intra-articular damage associated with a longer duration of symptoms result in damage and/or an altered intra-articular environment that predisposes to worse outcomes despite the benefits observed after hip arthroscopy. The data from our study serve as important prognostic evidence that may encourage shorter trials of nonsurgical treatment recommended by treating surgeons to avoid suboptimal outcomes in the medium term. Limitations A few limitations are important to consider in the context of the results presented in this study. Pain duration prior to hip arthroscopy was self-reported and therefore is not an objective measure, potentially subjecting the study to recall bias. Furthermore, at baseline, patients with a duration of symptoms of 2 or more years prior to hip arthroscopy had greater BMI values and were older on average than those with a shorter symptom duration; however, we performed rigorous statistical modeling controlling for 8 additional covariates, which reduced the amount of confounding and identified the duration of symptoms as an independent
predictor of outcomes. Despite this model, certain factors including femoral version, psychiatric history, back-pain screening, and distance to the treatment site were not controlled for and may have potentially influenced outcomes. Although many statistically significant differences were identified when the 2 cohorts were compared, there were only 120 patients in the cohort with a duration of symptoms of 2 or more years, and certain analyses may have been underpowered. All patients were treated at a large, tertiary center dedicated to arthroscopic hip-preservation surgery, and the current sample of patients only represents 1 series of patients; this may limit the external validity of the results. However, the consistently inferior findings observed for most outcomes in the cohort with a greater duration of pain advocates for the accuracy of results. It is also important to consider that our assessment of all the patients included in this studydand in generaldis limited to a physical examination, history, and imaging of the symptomatic and contralateral hips. Examples of symptoms observed in both cohorts included pain, limited range of motion, mechanical symptoms, and pain with flexion, adduction, and internal rotation and flexion, abduction, and external rotation testing, as well as palpation of the hip joint and surrounding osseous structures such as the pubic symphysis and sacroiliac joint. The examination does not include an examination of the lumbar spine, nor does it include a consistent assessment of femoral version; however, we do agree that these are important considerations in select patients and should be the subject of future study.
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME
Conclusions Patients with a preoperative duration of FAISassociated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up.
12.
13.
References 1. Lansdown DA, Kunze K, Ukwuani G, Waterman BR, Nho SJ. The importance of comprehensive cam correction: Radiographic parameters are predictive of patient-reported outcome measures at 2 years after hip arthroscopy. Am J Sports Med 2018;46:2072-2078. 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. Kuhns BD, Hannon CP, Makhni EC, et al. A comparison of clinical outcomes after unilateral or bilateral hip arthroscopic surgery: Age- and sex-matched cohort study. Am J Sports Med 2017;45:3044-3051. 4. Levy DM, Kuhns BD, Frank RM, et al. High rate of return to running for athletes after hip arthroscopy for the treatment of femoroacetabular impingement and capsular plication. Am J Sports Med 2017;45:127-134. 5. Kunze KN, Leong NL, Beck EC, Bush-Joseph CA, Nho SJ. Hip arthroscopy for femoroacetabular impingement improves sleep quality postoperatively. Arthroscopy 2019;35: 461-469. 6. Menge TJ, Briggs KK, Dornan GJ, McNamara SC, Philippon MJ. Survivorship and outcomes 10 years following hip arthroscopy for femoroacetabular impingement: Labral debridement compared with labral repair. J Bone Joint Surg Am 2017;99:997-1004. 7. Griffin DR, Dickenson EJ, Wall PDH, et al. Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): A multicentre randomised controlled trial. Lancet 2018;391:2225-2235. 8. Domb BG, Chaharbakhshi EO, Rybalko D, Close MR, Litrenta J, Perets I. Outcomes of hip arthroscopic surgery in patients with Tönnis grade 1 osteoarthritis at a minimum 5-year follow-up: A matched-pair comparison with a Tönnis grade 0 control group. Am J Sports Med 2017;45: 2294-2302. 9. Ashberg L, Charharbakhshi EO, Perets I, Yuen LC, Walsh JP, Domb BG. Hip arthroscopic surgery with labral preservation and capsular plication in patients with borderline hip dysplasia: Minimum 5-year patientreported outcomes: Response. Am J Sports Med 2019;47: NP32-NP33 (letter). 10. Ashberg L, Close MR, Perets I, et al. Do femoral head osteochondral lesions predict a poor outcome in hip arthroscopy patients? A matched control study with minimum 5-year follow-up. Arthroscopy 2019;35:419-431. 11. Perets I, Chaharbakhshi EO, Mu B, et al. Hip arthroscopy in patients ages 50 years or older: Minimum 5-year
14.
15.
16.
17.
18.
19.
20.
21.
22.
23. 24.
25.
26.
7
outcomes, survivorship, and risk factors for conversion to total hip replacement. Arthroscopy 2018;34:3001-3009. Perets I, Chaharbakhshi EO, Shapira J, Ashberg L, Mu BH, Domb BG. Hip arthroscopy for femoroacetabular impingement and labral tears in patients younger than 50 years: Minimum five-year outcomes, survivorship, and risk factors for reoperations. J Am Acad Orthop Surg 2019;27:e173-e183. Perets I, Rybalko D, Chaharbakhshi EO, Mu BH, Chen AW, Domb BG. Minimum five-year outcomes of hip arthroscopy for the treatment of femoroacetabular impingement and labral tears in patients with obesity: A match-controlled study. J Bone Joint Surg Am 2018;100: 965-973. Basques BA, Waterman BR, Ukwuani G, et al. Preoperative symptom duration is associated with outcomes after hip arthroscopy. Am J Sports Med 2019;47:131-137. 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. 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. Slikker W III, Van Thiel GS, Chahal J, Nho SJ. The use of double-loaded suture anchors for labral repair and capsular repair during hip arthroscopy. Arthrosc Tech 2012;1:e213-e217. Harris JD, Slikker W III, Gupta AK, McCormick FM, Nho SJ. Routine complete capsular closure during hip arthroscopy. Arthrosc Tech 2013;2:e89-e94. 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, Kelly BT, Philippon MJ. Evidence of validity for the hip outcome score. Arthroscopy 2006;22: 1304-1311. Martin RL, Philippon MJ. Evidence of reliability and responsiveness for the hip outcome score. Arthroscopy 2008;24:676-682. Byrd JW. Hip arthroscopy: Patient assessment and indications. Instr Course Lect 2003;52:711-719. 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. 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. 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
8
27.
28.
29.
30.
K. N. KUNZE ET AL. femoroacetabular impingement. Am J Sports Med 2017;45: 612-619. Chahal J, Van Thiel GS, Mather RC III, et al. The patient acceptable symptomatic state for the modified Harris Hip Score and Hip Outcome Score among patients undergoing surgical treatment for femoroacetabular impingement. Am J Sports Med 2015;43: 1844-1849. 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. 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. Michener LA, Snyder Valier AR, McClure PW. Defining substantial clinical benefit for patient-rated outcome tools
31.
32.
33.
34.
for shoulder impingement syndrome. Arch Phys Med Rehabil 2013;94:725-730. 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. Litrenta JM, Mu BH, Chen AW, Perets I, Ortiz-Declet V, Domb BG. Arthroscopic labral treatment in adolescents: Clinical outcomes with minimum 5-year follow-up. Am J Sports Med 2019;47:870-875. Maldonado DR, LaReau JM, Perets I, et al. Outcomes of hip arthroscopy with concomitant periacetabular osteotomy, minimum 5-year follow-up. Arthroscopy 2019;35: 826-834. Domb BG, Rybalko D, Mu B, Litrenta J, Chen AW, Perets I. Acetabular microfracture in hip arthroscopy: Clinical outcomes with minimum 5-year follow-up. Hip Int 2018;28:649-656.
Purpose: To determine the effect of the preoperative duration of femoroacetabular impingement syndrome (FAIS)e associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy. Methods: We identified FAIS patients who underwent primary hip arthroscopy between January 2012 and January 2014 with a minimum of 5 years’ follow-up. Patient demographic characteristics and clinical outcomes, comprising the Hip Outcome ScoreeActivities of Daily Living (HOS-ADL), Hip Outcome ScoreeSports Subscale (HOS-SS), modified Harris Hip Score (mHHS), pain score, and satisfaction score, were analyzed. The minimal clinically important difference, patient acceptable symptomatic state, and substantial clinical benefit were calculated. Patients were stratified based on the preoperative duration of symptoms: less than 2 years versus 2 years or longer. Multivariate regressions were constructed to determine the association between the preoperative symptom duration and clinical outcomes at 5 years after hip arthroscopy. Results: A total of 310 patients were included with a mean age (standard deviation) of 34.1 11.9 years and body mass index of 25.3 5.1. The study group showed statistically significant improvements in the HOS-ADL, HOS-SS, mHHS, pain score, and satisfaction score (P < .001 for all). A preoperative duration of symptoms of 2 or more years was an independent predictor of worse HOS-ADL, HOS-SS, mHHS, and pain score (P < .05 for all). Furthermore, a longer duration of symptoms was associated with a lower likelihood of achieving the minimal clinically important difference for the HOSADL (odds ratio [OR], 0.53; P ¼ .037), HOS-SS (OR, 0.38; P ¼ .003), and mHHS (OR, 0.43; P ¼ .009); the patient acceptable symptomatic state for the HOS-SS (OR, 0.44; P ¼ .006) and mHHS (OR, 0.46; P ¼ .006) but not the HOS-ADL despite trending toward significance (OR, 0.59; P ¼ .098); and substantial clinical benefit for the HOS-ADL (OR, 0.50; P ¼ .011), HOS-SS (OR, 0.52; P ¼ .020), and mHHS (OR, 0.47; P ¼ .007). Conclusions: Patients with a preoperative duration of FAIS-associated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up. Level of Evidence: Level III, retrospective comparative trial.
A
rthroscopic hip-preservation surgery for the treatment of femoroacetabular impingement syndrome (FAIS) is now an increasingly common intervention that has been shown to confer
improvements in functional status and patient-reported pain in multiple contexts.1-7 FAIS has been defined as symptomatic hip pain and dysfunction due to osseous abnormalities of the hip joint. With the adoption of hip
From the Section of Young Adult Hip Surgery, Division of Sports Medicine, Department of Orthopedic Surgery, Rush University Medical Center (K.N.K., B.U.N., E.C.B., J.C., J.R., S.J.N.), Chicago, Illinois; and Department of Orthopaedic Surgery, Wake Forest School of Medicine (A.K.G.), Winston-Salem, North Carolina, U.S.A. The authors report the following potential conflicts of interest or sources of funding: B.U.N. receives hospitality payments from Stryker, Wright Medical Technology, and Zimmer Biomet. S.J.N. receives research support from Allosource, Arthrex, Athletico, DJ Orthopaedics, Linvatec, Miomed, Smith & Nephew, and Stryker; serves on the editorial/governing board of the American Journal of Orthopedics; is a board/committee member of the American Orthopaedic Society for Sports Medicine and Arthroscopy Association of North America; receives IP royalties from and is a paid consultant for Ossur; and
receives publishing royalties and financial/material support from Springer. Full ICMJE author disclosure forms are available for this article online, as supplementary material. Paper previously presented at: International Society of Hip Arthroscopy Annual Conference, Madrid, Spain, October 17e19, 2019. Received May 8, 2019; accepted August 19, 2019. Address correspondence to Shane J. Nho, M.D., M.S., Department of Orthopaedics, Rush University Medical Center, 1611 W Harrison St, Ste 300, Chicago, IL 60612, U.S.A. E-mail: [email protected] Ó 2019 by the Arthroscopy Association of North America 0749-8063/19584/$36.00 https://doi.org/10.1016/j.arthro.2019.08.032
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol
-,
No
-
(Month), 2019: pp 1-8
1
2
K. N. KUNZE ET AL.
arthroscopy as a common means of treating FAIS, midto long-term outcomes are now being reported, which have reinforced the durability of clinical improvement.8-13 Many clinical variables shown to influence outcomes at 2 years after hip arthroscopy for FAIS have yet to be studied at these longer postoperative intervals, and their effect remains unknown. One such clinical consideration is the duration of FAIS-associated symptoms prior to arthroscopic intervention. Basques et al.14 performed a retrospective cohort study of 624 patients with FAIS and stratified them based on a preoperative duration of symptoms of less than 24 months versus 24 months or longer. They showed that patients who experienced a longer preoperative duration of symptoms had significantly worse patient-reported outcomes and higher rates of reoperation at 2 years than patients with a shorter preoperative symptom duration. Given this clinical significance, it is important to determine whether such a relationship is maintained at longer-term follow-up. The purpose of this study was to determine the effect of the preoperative duration of FAIS-associated symptoms on clinical outcomes at a minimum of 5 years after hip arthroscopy. We hypothesized that patients with a longer duration of symptoms would experience worse clinical outcomes and more pain and would achieve a lower rate of clinically significant outcome improvement at a minimum of 5 years after hip arthroscopy.
Methods Patient Selection This study received institutional review board approval to record and retrospectively analyze the clinical outcomes of patients who underwent hip arthroscopy for FAIS. All patients were treated by the senior author (S.J.N.) at a large, tertiary center dedicated to arthroscopic hip-preservation surgery. All patients undergoing primary hip arthroscopy for the treatment of FAIS between January 1, 2012, and January 31, 2014, were included in this study. The inclusion criteria consisted of a clinical and radiographic diagnosis of symptomatic FAIS,15 failure of conservative management (physical therapy, activity modification, oral anti-inflammatories, and intra-articular cortisone injections), and a minimum of 5 years’ follow-up. The exclusion criteria consisted of patients with congenital hip conditions (slipped capital femoral epiphysis, developmental hip dysplasia, avascular necrosis, and so on), patients undergoing concomitant gluteus medius repairs, patients who underwent prior ipsilateral hip surgery, patients with signs of osteoarthritis (Tönnis grade >1), and patients with hip dysplasia (lateral center-edge angle <20 ). Patients were stratified based on whether they had experienced FAIS-related symptoms for 2 or more years
prior to hip arthroscopy. We chose a 2-year symptom duration because this has been used for stratification previously in the literature on femoroacetabular impingement.14 Related symptoms in both cohorts included primary hip complaints such as hip pain with active and passive range of motion, limitations of daily activities, decreased range of motion, mechanical symptoms, and pain with palpation to osseous structures such as the sacroiliac joint and the pubic symphysis on physical examination. Surgical Technique All hip arthroscopies were performed by a single fellowship-trained hip surgeon (S.J.N.) at a highvolume academic hospital using a technique that has been well described in the literature.16-18 In brief, an interportal capsulotomy was created, and pathology in the central compartment was addressed; the procedures included acetabuloplasty, labral debridement in cases of salvageable labral tissue, or labral repair for significant tears. A vertical T-capsulotomy was performed to address cam pathology in the peripheral compartment. On completion, a dynamic examination of the operative leg was performed to confirm appropriate resolution of impingement. The capsule was then repaired using a suture shuttling system, and plication was performed depending on the degree of capsular laxity. Rehabilitation was started on postoperative day 1 in all patients as previously described.19,20 Clinical Outcome Evaluation Patients completed hip-specific outcome instruments at preoperative visits and at a minimum of 5 years postoperatively. Hip outcome instruments included the Hip Outcome ScoreeActivities of Daily Living (HOSADL),21 Hip Outcome ScoreeSports Subscale (HOSSS),22 modified Harris Hip Score (mHHS),23 visual analog scale (VAS) for pain, and VAS for satisfaction. To determine clinically significant outcome improvement, the minimal clinically important difference (MCID) for the HOS-ADL, HOS-SS, and mHHS was calculated based on one-half of the standard deviation of the entire study cohort for the HOS-ADL, HOS-SS, and mHHS, respectively.24-26 The patient acceptable symptomatic state (PASS)27 and substantial clinical benefit (SCB)28 for the HOS-ADL, HOS-SS, and mHHS were calculated using anchor-based methods and receiver operating characteristic curves. The anchor question for the PASS was as follows: “Taking into account all the activities you have during your daily life, your level of pain, and also your functional impairment, do you consider that your current state is satisfactory?” The PASS value was then identified using receiver operating characteristic curve analysis as has been shown to be feasible in the literature.27,29 Sensitivity and specificity values of 0.80 were used as the
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME
cutoff values for determining the threshold cutoff scores. SCB was calculated similarly to the PASS using an anchor-based method. Patients were asked the following question: “Since your surgery, has there been any change in your daily functioning and non-sporting activities related to your treated hip?” The available choices were as follows: "a very great deal better," "a great deal better," "a good deal better," "moderately better," "a little better," "somewhat better," "almost the same/hardly any better," "no change," "almost the same/hardly any worse," "somewhat worse," "a little worse," "moderately worse," "a good deal worse," "a great deal worse," and "a very great deal worse." Patients responding "a very great deal better," "a great deal better," or "a good deal better" were classified as the “much improved group,” whereas patients responding “almost the same/hardly any better," "no change," or "almost the same/hardly any worse" were classified as the “no change group.” As shown in previous studies, pain and physical anchor questions are useful for psychometric analysis to identify clinically meaningful improvements in function.28,30,31 As with prior psychometric studies in the orthopaedic literature, an area under the curve greater than 0.8 was considered acceptably predictive.28 Statistical Analysis Continuous variables were presented as means with standard deviations and ranges, whereas categorical variables were presented as frequencies with percentages. Data were analyzed for normality of distribution prior to analysis, and appropriate parametric or nonparametric tests were used to compare variables at baseline. Paired t tests were performed to determine whether mean patient-reported outcome scores significantly differed at latest follow-up relative to preoperative values. Multivariate linear regression models were constructed controlling for age, body mass index (BMI), sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade) to determine statistically significant associations between the preoperative symptom duration and the (1) HOS-ADL (2) HOS-SS, (3) mHHS, (4) VAS pain score, and (5) VAS satisfaction score postoperatively at a minimum of 5 years. Multivariate logistic regression models controlling for the same covariates were performed to determine associations between the preoperative symptom duration and (1) the MCID for the HOS-ADL, HOS-SS, and mHHS; (2) the PASS for the HOS-ADL, HOS-SS, and mHHS; and (3) SCB for the HOS-ADL, HOS-SS, and mHHS at a minimum of 5 years postoperatively. All statistical analyses were performed using Stata software (version 15.1; StataCorp, College Station, TX). Statistical significance was set at P < .05.
3
Results Of the 425 patients for whom the perioperative pain duration was recorded, 310 (79.7%) met the inclusion criteria and were included in the final analysis; a total of 79 patients did not fill out the questionnaire (Fig 1). The study group had a mean age (standard deviation) of 34.1 11.9 years and BMI of 25.3 5.1. Of the 310 patients, 190 (61.3%) were female patients and 198 (63.9%) were involved in sports activity (Table 1). All of the patients included in the study underwent femoroplasty, acetabuloplasty or rim trimming, and capsular closure. The rest of the procedures are summarized in Table 2. The study group showed statistically significant improvements at 5 years after hip arthroscopy in average values for the HOS-ADL (83.7 19.9 vs 67.3 19.6, P < .001), HOS-SS (73.5 28.8 vs 45.9 23.8, P < .001), mHHS (77.3 22.7 vs 58.2 15.6, P < .001), and VAS pain score (74.2 18.6 vs 29.8 29.8, P < .001). Preoperative Symptom Duration and Stratification A total of 120 patients (38.7%) reported experiencing symptoms for a duration of 2 or more years (Table 1). Patients with a duration of preoperative FAIS-related symptoms of 2 or more years were older (P ¼ .014) and had greater BMI values (P ¼ .002) than patients with a shorter duration of symptoms when the 2 cohorts were compared. No significant differences in patient-reported outcome measures were found preoperatively; however, patients with FAIS-associated symptoms for 2 or more years had significantly greater HOS-ADL (88.1 16.5 vs 79.6 21.9, P ¼ .001), HOS-SS (79.1 25.9 vs 65.0 32.2, P < .001), and mHHS (81.3 21.5 vs 72.0 24.7, P ¼ .005) values, as well as a significantly lower VAS pain score (24.8 25.6 vs 34.7 31.1, P ¼ .012), at a minimum of
Fig 1. Flowchart describing patient population in final analysis, including exclusion and inclusion criteria. (FAIS, femoroacetabular impingement syndrome.)
4
K. N. KUNZE ET AL.
Table 1. Baseline Patient Characteristics No. of patients Demographic characteristics Age, yr BMI Female Sports activity Smoking Workers’ Compensation Pain duration, mo Radiographic parameters Alpha angle, LCEA, Tönnis grade 1
Preoperative Symptoms <2 yr 190
Preoperative Symptoms 2 yr 120
All Patients 310
P Value
32.3 12.0 24.5 4.5 115 (60.5) 131 (68.9) 11 (5.8) 14 (7.4) 9.8 5.3
36.2 11.4 26.4 5.8 75 (62.5) 97 (80.8) 14 (11.7) 2 (1.7) 54.7 49.2
34.1 11.9 25.3 5.1 190 (61.3) 198 (63.9) 25 (8.1) 16 (5.2) 27.0 37.6
.014* .002* .89 .52 .07 .06 <.001*
59.2 9.8 33.4 6.8 13 (6.8)
61.9 10.1 33.8 7.6 21 (17.5)
60.7 10.1 33.6 7.1 34 (11)
.81 .61 .07
NOTE. Baseline Characteristics Were Analyzed Using Independent t Tests or the c2 Test of Association When Appropriate. Continuous Variables are Reported as Mean Standard Deviation, Whereas Categorical Variables are Reported as Number (Frequency). BMI, body mass index; LCEA, lateral center-edge angle. *Statistically significant at P < .05 level.
5 years postoperatively (Table 3). No statistically significant difference was found in VAS satisfaction scores. A series of multivariate linear regression models were subsequently constructed controlling for baseline covariates to determine whether symptom duration was independently associated with postoperative outcomes at 5 years. These models indicated that a preoperative symptom duration of 2 or more years was significantly and independently associated with worse HOS-ADL, HOS-SS, mHHS, and VAS pain scores at a minimum of 5 years postoperatively (Table 4). Binary logistic regression models were constructed to determine whether the preoperative symptom duration was predictive of achieving meaningful clinical outcomes as defined by the MCID, PASS, or SCB (Table 5). These analyses revealed that patients with a preoperative symptom duration of 2 or more years were less likely to reach the HOS-ADL (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.29-0.96; P ¼ .037), HOS-SS (OR, 0.38; 95% CI, 0.2-0.72; P ¼ .003), and mHHS (OR, 0.43; 95% CI, 0.23-0.81 P ¼ .009) threshold scores for achieving the MCID. A preoperative symptom duration of 2 or more years was also independently associated with a lower likelihood of reaching the HOS-SS (OR, 0.44; 95% CI, 0.25-0.79;
Table 2. Operative Procedures Acetabuloplasty or rim trimming Femoroplasty Labral repair Labral debridement Excision of os acetabuli Removal of loose body Trochanteric bursectomy Microfracture Capsular closure
n (%) 310 (100) 310 (100) 302 (97.4) 8 (2.6) 2 (0.6) 1 (0.3) 2 (0.6) 1 (0.3) 310 (100)
P ¼ .006) and mHHS (OR, 0.46; 95% CI, 0.27-0.81; P ¼ .006) threshold scores for achieving the PASS. Regarding SCB, patients with a preoperative symptom duration of 2 or more years were less likely to reach the HOS-ADL (OR, 0.50; 95% CI, 0.3-0.86; P ¼ .011), HOSSS (OR, 0.52; 95% CI, 0.3-0.9; P ¼ .020), and mHHS (OR, 0.47; 95% CI, 0.27-0.81; P ¼ .007) threshold scores for achieving SCB. Among the entire cohort of 310 patients, a total of 4 revisions (1.3%) had been performed at 5 years postoperatively. In the cohort with a symptom duration of 2 or more years, there were 2 revisions (1.9%); likewise, in the control cohort, there were 2 revisions (1.2%). In a multivariate logistic regression analysis, the duration of symptoms was not independently associated with revision hip arthroscopy at 5 years (OR, 1.5; 95% CI, 0.22-11.5; P ¼ .64).
Discussion The primary findings of this study were that patients who experienced FAIS-associated symptoms for 2 or more years prior to hip arthroscopy had worse clinical outcomes as determined by inferior HOS-ADL (88.1 vs 79.6), HOS-SS (79.1 vs 65.0), and mHHS (81.3 vs 72.0) values and VAS satisfaction scores (75.3 vs 69.7), as well as more pain (34.8 vs 34.7), at a minimum of 5 years postoperatively. Furthermore, patients who experienced a symptom duration of 2 or more years showed less clinically significant outcome improvement as determined by the lower proportion of MCID, PASS, and SCB achievement by this cohort for the HOS-ADL, HOS-SS, and mHHS. In addition, we found an independent association between a symptom duration of 2 or more years and a lower likelihood of achieving the MCID and SCB for the HOS-ADL, HOS-SS, and mHHS, as well as the PASS for the HOS-SS and mHHS, at 5 years after hip arthroscopy.
5
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME Table 3. Comparison of Preoperative and Postoperative Outcome Scores Between Patient Groups Preoperative Symptom Duration <2 yr Preoperative outcome scores HOS-ADL HOS-SS mHHS VAS pain score 5-yr outcome scores HOS-ADL HOS-SS mHHS VAS pain score VAS satisfaction score
Preoperative Symptom Duration 2 yr
All Patients
P Value
68.9 46.0 58.2 75.2
18.4 23.6 14.3 15.7
65.0 43.4 55.8 71.9
20.7 25.7 16.7 21.0
67.4 45.0 57.3 73.9
19.3 24.4 15.2 18.0
.11 .42 .24 .21
88.1 79.1 81.3 24.8 75.3
16.5 25.9 21.5 25.6 31.3
79.6 65.0 72.0 34.7 69.7
21.9 32.2 24.7 31.1 34.9
84.5 73.1 77.4 28.7 73.1
19.4 29.5 23.3 28.3 32.8
.001* <.001* .005* .012* .2
NOTE. Data are presented as mean standard deviation. HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; mHHS, modified Harris Hip Score; VAS, visual analog scale. *Statistically significant at P < .05 level.
A variety of preoperative clinical variables have been investigated with respect to their potential influence on postoperative outcomes at 5 years after hip arthroscopy for FAIS. Indeed, factors such as the Tönnis grade,8 age,12,32 borderline hip dysplasia,9 concomitant periacetabular osteotomy33 or microfracture,34 femoral head osteochondral lesions,10 and obesity13 have been studied within the context of mid-term outcomes. The evolution of literature seeking to describe the influence of such factors is essential as patients become further removed from arthroscopic intervention and need to be counseled on expectations. Despite the continued identification of prognostic factors, many factors that have been shown to influence short-term outcomes after hip arthroscopy remain poorly understood.
Table 4. Multivariate Linear Regression Model for Influence of Preoperative Duration of FAIS-Associated Symptoms on 5-Year Outcome Scores, With Preoperative Symptom Duration less than 2 Years as Reference Variable Outcome HOS-ADL HOS-SS mHHS VAS pain score VAS satisfaction score
b* e5.5 e12.1 e9.6 9.6 e6.5
95% CI e10.7 to e0.22 e20.7 to e3.6 e16.9 to e2.2 1.3 to 17.9 e16.0 to 3.09
P Value .041y .006y .011y .023y .18
CI, confidence interval; FAIS, femoroacetabular impingement syndrome; HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; mHHS, modified Harris Hip Score; VAS, visual analog scale. *The multivariate linear regression model controlled for age, body mass index, sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade). The b value describes the magnitude of change that the independent effect of symptom duration has on each outcome variable relative to patients with a shorter symptom duration. y Statistically significant at P < .05 level.
Our study examined the influence of the duration of preoperative FAIS-associated symptoms on postoperative outcomes in the medium to long term. A longer duration of preoperative symptoms, specifically 2 or more years prior to hip arthroscopy, is known to predispose patients to worse clinical outcomes and a lower rate of clinically significant outcome improvement at 2 years after hip arthroscopy.14 It appears that this effect persists in the medium to long term. Our study showed that patients with a preoperative duration of symptoms of 2 or more years prior to hip arthroscopy experienced inferior clinical outcomes and persistently greater pain at a minimum of 5 years after hip arthroscopy compared with patients with a shorter duration of symptoms. Despite this finding, it should be noted that symptom duration was a self-reported variable and is inherently subjective, which may introduce bias. Together, these data hold potential clinical implications for prognosticating, counseling patients on expectations, and potentially expediting arthroscopic intervention; however, it is important to acknowledge that basic statistical comparisons of absolute patientreported outcome measures may be subject to confounding. Furthermore, it is often unclear to the treating surgeon and patient how relevant these absolute outcome scores are because they do not necessarily reflect the patient’s perception of his or her improvement. For these reasons, this study performed multivariate logistic regression models that controlled for potential confounding variables, which may influence outcomes, and examined psychometric measures (MCID, PASS, and SCB), which more appropriately indicate the clinical significance of improvement for each patient. Such models minimize statistical bias and provide an inherently more reliable assessment of outcome. The results of these additional analyses indicated that a preoperative symptom duration of 2 or more years was a risk factor for
6
K. N. KUNZE ET AL.
Table 5. Multivariate Logistic Regression Model for Influence of Preoperative Duration of FAIS-Associated Symptoms on 5-Year Rates of Clinically Significant Outcome Improvement, With Preoperative Symptom Duration less than 2 Years as Reference Variable
Outcome MCID HOS-ADL HOS-SS mHHS PASS HOS-ADL HOS-SS mHHS SCB HOS-ADL HOS-SS mHHS
Multivariate Logistic Regression*
Preoperative Symptom Duration <2 yr, n (%)
Preoperative Symptom Duration 2 yr, n (%)
All Patients, n (%)
OR
P Value
144 (75.8) 152 (80.0) 154 (81.1)
80 (66.7) 84 (70.0) 87 (72.5)
224 (72.3) 236 (76.1) 241 (77.7)
0.53 0.38 0.43
.037y .003y .009y
145 (76.3) 138 (72.6) 125 (65.8)
81 (67.5) 75 (62.5) 65 (54.2)
226 (72.9) 213 (68.7) 190 (61.3)
0.59 0.44 0.46
.098 .006y .006y
105 (55.2) 130 (68.4) 114 (60.0)
52 (43.3) 71 (59.2) 58 (48.3)
157 (50.6) 201 (64.8) 172 (55.5)
0.50 0.52 0.47
.011y .020y .007y
FAIS, femoroacetabular impingement syndrome; HOS-ADL, Hip Outcome ScoreeActivities of Daily Living; HOS-SS, Hip Outcome ScoreeSports Subscale; MCID, minimal clinically important difference; mHHS, modified Harris Hip Score; OR, odds ratio; PASS, patient acceptable symptomatic state; SCB, substantial clinical benefit. *Multivariate logistic regression model controlling for age, body mass index, sex, Workers’ Compensation status, smoking status, sporting activity, and disease severity (alpha angle, lateral center-edge angle, and Tönnis grade). y Statistically significant at P < .05 level.
less frequent clinically significant outcome improvement in terms of the MCID, PASS, and SCB; this finding is in accordance with the findings of a short-term study performed by Basques et al.14 Specifically, a symptom duration of 2 or more years portended a lower likelihood for all included psychometric measures with the exception of the PASS for the HOS-ADL, suggesting that this aspect of a patient’s history holds significant clinical implications. It is possible that compensatory changes to the symptomatic hip and subsequent intra-articular damage associated with a longer duration of symptoms result in damage and/or an altered intra-articular environment that predisposes to worse outcomes despite the benefits observed after hip arthroscopy. The data from our study serve as important prognostic evidence that may encourage shorter trials of nonsurgical treatment recommended by treating surgeons to avoid suboptimal outcomes in the medium term. Limitations A few limitations are important to consider in the context of the results presented in this study. Pain duration prior to hip arthroscopy was self-reported and therefore is not an objective measure, potentially subjecting the study to recall bias. Furthermore, at baseline, patients with a duration of symptoms of 2 or more years prior to hip arthroscopy had greater BMI values and were older on average than those with a shorter symptom duration; however, we performed rigorous statistical modeling controlling for 8 additional covariates, which reduced the amount of confounding and identified the duration of symptoms as an independent
predictor of outcomes. Despite this model, certain factors including femoral version, psychiatric history, back-pain screening, and distance to the treatment site were not controlled for and may have potentially influenced outcomes. Although many statistically significant differences were identified when the 2 cohorts were compared, there were only 120 patients in the cohort with a duration of symptoms of 2 or more years, and certain analyses may have been underpowered. All patients were treated at a large, tertiary center dedicated to arthroscopic hip-preservation surgery, and the current sample of patients only represents 1 series of patients; this may limit the external validity of the results. However, the consistently inferior findings observed for most outcomes in the cohort with a greater duration of pain advocates for the accuracy of results. It is also important to consider that our assessment of all the patients included in this studydand in generaldis limited to a physical examination, history, and imaging of the symptomatic and contralateral hips. Examples of symptoms observed in both cohorts included pain, limited range of motion, mechanical symptoms, and pain with flexion, adduction, and internal rotation and flexion, abduction, and external rotation testing, as well as palpation of the hip joint and surrounding osseous structures such as the pubic symphysis and sacroiliac joint. The examination does not include an examination of the lumbar spine, nor does it include a consistent assessment of femoral version; however, we do agree that these are important considerations in select patients and should be the subject of future study.
PREOPERATIVE SYMPTOMS AND 5-YEAR FAIS OUTCOME
Conclusions Patients with a preoperative duration of FAISassociated symptoms of 2 or more years prior to hip arthroscopy experience inferior outcomes and a lower frequency of clinically significant outcome improvement than patients with a shorter duration of symptoms at medium-to long-term follow-up.
12.
13.
References 1. Lansdown DA, Kunze K, Ukwuani G, Waterman BR, Nho SJ. The importance of comprehensive cam correction: Radiographic parameters are predictive of patient-reported outcome measures at 2 years after hip arthroscopy. Am J Sports Med 2018;46:2072-2078. 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. Kuhns BD, Hannon CP, Makhni EC, et al. A comparison of clinical outcomes after unilateral or bilateral hip arthroscopic surgery: Age- and sex-matched cohort study. Am J Sports Med 2017;45:3044-3051. 4. Levy DM, Kuhns BD, Frank RM, et al. High rate of return to running for athletes after hip arthroscopy for the treatment of femoroacetabular impingement and capsular plication. Am J Sports Med 2017;45:127-134. 5. Kunze KN, Leong NL, Beck EC, Bush-Joseph CA, Nho SJ. Hip arthroscopy for femoroacetabular impingement improves sleep quality postoperatively. Arthroscopy 2019;35: 461-469. 6. Menge TJ, Briggs KK, Dornan GJ, McNamara SC, Philippon MJ. Survivorship and outcomes 10 years following hip arthroscopy for femoroacetabular impingement: Labral debridement compared with labral repair. J Bone Joint Surg Am 2017;99:997-1004. 7. Griffin DR, Dickenson EJ, Wall PDH, et al. Hip arthroscopy versus best conservative care for the treatment of femoroacetabular impingement syndrome (UK FASHIoN): A multicentre randomised controlled trial. Lancet 2018;391:2225-2235. 8. Domb BG, Chaharbakhshi EO, Rybalko D, Close MR, Litrenta J, Perets I. Outcomes of hip arthroscopic surgery in patients with Tönnis grade 1 osteoarthritis at a minimum 5-year follow-up: A matched-pair comparison with a Tönnis grade 0 control group. Am J Sports Med 2017;45: 2294-2302. 9. Ashberg L, Charharbakhshi EO, Perets I, Yuen LC, Walsh JP, Domb BG. Hip arthroscopic surgery with labral preservation and capsular plication in patients with borderline hip dysplasia: Minimum 5-year patientreported outcomes: Response. Am J Sports Med 2019;47: NP32-NP33 (letter). 10. Ashberg L, Close MR, Perets I, et al. Do femoral head osteochondral lesions predict a poor outcome in hip arthroscopy patients? A matched control study with minimum 5-year follow-up. Arthroscopy 2019;35:419-431. 11. Perets I, Chaharbakhshi EO, Mu B, et al. Hip arthroscopy in patients ages 50 years or older: Minimum 5-year
14.
15.
16.
17.
18.
19.
20.
21.
22.
23. 24.
25.
26.
7
outcomes, survivorship, and risk factors for conversion to total hip replacement. Arthroscopy 2018;34:3001-3009. Perets I, Chaharbakhshi EO, Shapira J, Ashberg L, Mu BH, Domb BG. Hip arthroscopy for femoroacetabular impingement and labral tears in patients younger than 50 years: Minimum five-year outcomes, survivorship, and risk factors for reoperations. J Am Acad Orthop Surg 2019;27:e173-e183. Perets I, Rybalko D, Chaharbakhshi EO, Mu BH, Chen AW, Domb BG. Minimum five-year outcomes of hip arthroscopy for the treatment of femoroacetabular impingement and labral tears in patients with obesity: A match-controlled study. J Bone Joint Surg Am 2018;100: 965-973. Basques BA, Waterman BR, Ukwuani G, et al. Preoperative symptom duration is associated with outcomes after hip arthroscopy. Am J Sports Med 2019;47:131-137. 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. 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. Slikker W III, Van Thiel GS, Chahal J, Nho SJ. The use of double-loaded suture anchors for labral repair and capsular repair during hip arthroscopy. Arthrosc Tech 2012;1:e213-e217. Harris JD, Slikker W III, Gupta AK, McCormick FM, Nho SJ. Routine complete capsular closure during hip arthroscopy. Arthrosc Tech 2013;2:e89-e94. 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, Kelly BT, Philippon MJ. Evidence of validity for the hip outcome score. Arthroscopy 2006;22: 1304-1311. Martin RL, Philippon MJ. Evidence of reliability and responsiveness for the hip outcome score. Arthroscopy 2008;24:676-682. Byrd JW. Hip arthroscopy: Patient assessment and indications. Instr Course Lect 2003;52:711-719. 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. 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. 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
8
27.
28.
29.
30.
K. N. KUNZE ET AL. femoroacetabular impingement. Am J Sports Med 2017;45: 612-619. Chahal J, Van Thiel GS, Mather RC III, et al. The patient acceptable symptomatic state for the modified Harris Hip Score and Hip Outcome Score among patients undergoing surgical treatment for femoroacetabular impingement. Am J Sports Med 2015;43: 1844-1849. 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. 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. Michener LA, Snyder Valier AR, McClure PW. Defining substantial clinical benefit for patient-rated outcome tools
31.
32.
33.
34.
for shoulder impingement syndrome. Arch Phys Med Rehabil 2013;94:725-730. 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. Litrenta JM, Mu BH, Chen AW, Perets I, Ortiz-Declet V, Domb BG. Arthroscopic labral treatment in adolescents: Clinical outcomes with minimum 5-year follow-up. Am J Sports Med 2019;47:870-875. Maldonado DR, LaReau JM, Perets I, et al. Outcomes of hip arthroscopy with concomitant periacetabular osteotomy, minimum 5-year follow-up. Arthroscopy 2019;35: 826-834. Domb BG, Rybalko D, Mu B, Litrenta J, Chen AW, Perets I. Acetabular microfracture in hip arthroscopy: Clinical outcomes with minimum 5-year follow-up. Hip Int 2018;28:649-656.