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Is Arthroscopic Coracoplasty Necessary in Subcoracoid Impingement Syndrome?
Is Arthroscopic Coracoplasty Necessary in Subcoracoid Impingement Syndrome? Jin-Young Park, M.D., Ph.D., Sang-Hoon Lhee, M.D., Ph.D., Kyung-Soo Oh, M.D., Na Ra Kim, M.D., Ph.D., and Jung-Taek Hwang, M.D., Ph.D.
Purpose: The purpose of this study was to analyze the outcomes of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome. Methods: We compared 23 shoulders that underwent arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome with 28 shoulders that did not undergo arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome, which comprised the control group. All the shoulders had subcoracoid and subacromial impingement syndrome with or without rotator cuff tear. Subcoracoid impingement was defined as a coracohumeral distance of less than 6 mm on the preoperative magnetic resonance image with anterior shoulder pain or tenderness. The 2 groups were further divided into several subgroups according to the size of concomitant rotator cuff tear, and a comparative analysis of functional outcomes after surgery among the subgroups was performed. Results: In the 2 groups, the overall functional outcomes improved after surgery. The study group showed a significant increase in internal rotation compared with that in the control group (P ⫽ .001) at the last follow-up. The large to massive rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .017). On the other hand, no significant difference was seen in the subgroups with small to medium rotator cuff tears including isolated subscapularis tears. The no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046). Conclusions: Arthroscopic coracoplasty for subcoracoid impingement syndrome can provide a satisfactory outcome. In particular, a significant increase in internal rotation of the treated group was achieved after surgery in comparison with the untreated group, especially in the large to massive rotator cuff tear subgroup and in the no rotator cuff tear subgroup. Level of Evidence: Level III, retrospective comparative study.
S
From the Glocal Center for Shoulder & Elbow, Department of Orthopedic Surgery (J-Y.P., S-H.L., K-S.O.), and Department of Radiology (N.R.K.), Konkuk University Hospital, Konkuk University School of Medicine, Seoul; and Department of Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University Medical College(J-T.H.), Gangwon-do, South Korea. This work was supported by Konkuk University in 2011. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received January 3, 2012; accepted June 4, 2012. Address correspondence to Jung-Taek Hwang, M.D., Ph.D., Department of Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University Medical College, 153, Gyo-dong, Chuncheon-si, Gangwon-do, 200-704, South Korea. E-mail: drakehjt@ hanmail.net © 2012 by the Arthroscopy Association of North America 0749-8063/0126/$36.00 http://dx.doi.org/10.1016/j.arthro.2012.06.013
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ubcoracoid impingement syndrome with associated subcoracoid stenosis has been known to be a cause of shoulder pain.1-5 The pain is thought to be caused by impingement of the subscapularis between the coracoid and lesser tuberosity when an affected shoulder is flexed, adducted, and internally rotated.1,6 Although some authors have noted that subcoracoid impingement frequently causes anterior shoulder pain and tenderness, there is no effective physical examination to determine the existence of the disease. Although arthroscopic coracoplasty was introduced for the treatment of subcoracoid impingement syndrome, there have been only a few studies examining this surgical technique.1,2,6,7 In 1985 Gerber et al.8 identified the role of the coracoid process in chronic impingement syndrome. Recently, a study reported the outcome of combined
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 28, No 12 (December), 2012: pp 1766-1775
SUBCORACOID IMPINGEMENT SYNDROME arthroscopic acromioplasty, coracoplasty, and rotator cuff repair,1 and another article reported that 13 patients who underwent arthroscopic coracoplasty showed satisfactory results.6 However, these 2 studies did not include a control group in which coracoplasty was not performed for the treatment of subcoracoid impingement syndrome. The aim of this study was to analyze the functional outcomes of arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome by a comparison between the study group and the control group. In addition, we had further divided the 2 groups into several subgroups according to the size of concomitant rotator cuff tear and compared the outcome among the subgroups to remove bias arising from rotator cuff tears. We hypothesized that arthroscopic coracoplasty was necessary for the treatment of subcoracoid impingement syndrome along with the treatment of concomitant diseases. METHODS All procedures described in this study were approved by the international review board of our hospital, and all patients gave written informed consent to participate in this study. Between July 31, 2006, and July 30, 2009, we performed 475 arthroscopic repairs or debridements of rotator cuff tears showing fraying at the least. Among them, 110 rotator cuff tears included subscapularis tears. Forty-four arthroscopic subacromial decompressions for patients who had subacromial impingement and did not have rotator cuff tears were performed. In addition, 1 patient with only subcoracoid impingement syndrome underwent an arthroscopic coracoplasty. Among the 520 patients, 81 who had a coracohumeral distance (CHD) of less than 6 mm with anterior shoulder pain or tenderness were diagnosed as having subcoracoid impingement syndrome.1,6,9 Arthroscopic coracoplasty was performed for 37 patients among the 81 with subcoracoid impingement. The decision of whether to perform an arthroscopic coracoplasty was made randomly by the operating surgeon during the operation regardless of demographic or operative data, such as age, rotator cuff tear, and CHD. We classified a rotator cuff tear with a length smaller than 1 cm as small, a tear measuring 1 to 3 cm as medium, a tear measuring 3 to 5 cm as large, and a tear measuring larger than 5 cm as massive.10 In addition, a massive tear was defined as a detachment of at least 2 entire tendons.11 CHD was defined as the shortest distance between the humeral head and the coracoid process on an axial cut on preoperative mag-
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netic resonance imaging (MRI).9,12 Preoperative MRI was performed with the patient in the supine position with the upper extremity in its anatomic position. For the cases in the study group, the inclusion criteria were as follows: (1) a preoperative MRI study was available, (2) the patient underwent an arthroscopic acromioplasty and coracoplasty, (3) the CHD was less than 6 mm, and (4) the patient presented with anterior shoulder pain or tenderness. Some patients were excluded for the following reasons: (1) the patient had follow-up of less than 24 months, (2) the patient simultaneously underwent an operation for concomitant instability (SLAP lesion or Bankart lesion) or osteosynthesis of os acromiale, (3) the patient had incomplete repairs because of severe retraction or poor tissue quality of the torn rotator cuff, (4) the patient underwent anterior capsulotomy for adhesive capsulitis, (5) the patient had a history of previous shoulder operation, (6) the patient underwent open rotator cuff repairs, (7) the patient had calcific tendinitis, (8) the patient had a concomitant nerve injury around the shoulder, and (9) the patient had a traumatic rotator cuff tear. Among the 37 patients with subcoracoid impingement syndrome who underwent arthroscopic coracoplasty, the case with only subcoracoid impingement who underwent arthroscopic coracoplasty was excluded based on the inclusion criteria and 14 cases were excluded based on the exclusion criteria. The remaining 23 patients, who had undergone arthroscopic coracoplasty during the period, were included in the study group. Among them, the cases with rotator cuff tears had subscapularis pathology of fraying of the leading edge at the least. There were 3 cases without rotator cuff tears. On the other hand, the 44 candidates in the control group were selected based on the previously mentioned inclusion criteria except for the criterion that the shoulder had undergone an arthroscopic coracoplasty. There were 29 cases with a CHD of less than 6 mm and subscapularis pathology more than fraying of the subscapularis tendon. Among them, 4 cases were excluded based on the previously mentioned exclusion criteria. There were 15 cases without rotator cuff tears having a CHD of less than 6 mm and that underwent only acromioplasty. Among them, 12 cases were excluded in a similar manner. In the end, the remaining 28 cases among the 44 patients were enrolled in the control group. Among all the 51 patients of the study and control groups, the cases with rotator cuff tears had subscapularis pathology of fraying of the leading edge at the least.
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J-Y. PARK ET AL. TABLE 1.
Demographic and Operative Characteristics
Factor
Study
Control
No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* Operative data Concomitant rotator cuff tear Small to medium Large to massive Isolated SC No tear SC lesion Debridement Repair LHB pathology Absence Fraying (⬍50%) Partial tear (⬎50%) Subluxation Dislocation Tear with subluxation or dislocation Spontaneous rupture ADCR due to AC arthrosis
23
28
56.8 ⫾ 7.4 (45-72) 13:10 59.8 ⫾ 86.1 (3.0-362.0) 17:6 7.8 ⫾ 1.7 (5.1-11.5) 4.9 ⫾ 0.7 (3.1-5.9)
59.0 ⫾ 10.3 (39-77) 9:19 44.6 ⫾ 43.8 (2.3-133.0) 23:5 6.7 ⫾ 2.2 (1.8-10.9) 5.2 ⫾ 0.6 (3.9-5.9)
8 8 4 3
6 17 2 3
4 16
13 12
9 2 5 1 1 3 2 3
13 2 8 3 3 1 1 4
P Value
.400 .083 .616 .481 .060 .117
NOTE. Fraying was defined as a long head of the biceps lesion of less than 50%. Tenodesis or tenotomy was performed in cases with long head of the biceps dislocation, subluxation, or tear involving more than 50%. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data to evaluate the differences between the mean values of the study group and control group (with the significance level set at P ⬍ .05). Abbreviations: AC, acromioclavicular joint; ADCR, arthroscopic distal clavicle resection; AHI, acromiohumeral interval; LHB, long head of biceps; SC, subscapularis. *Data are presented as mean ⫾ standard deviation (range).
Power analysis indicated that a total sample size of 40 patients (20 patients in each cohort) would provide a statistical power of 90% with a 2-sided ␣ level of .05 to detect significant differences in internal rotation, assuming an effect size of 1.1 (mean difference, 3.3; SD, 2.9). This was based on the mean and standard deviation of internal rotation observed in a pilot study of 20 patients. Internal rotation was measured in an active manner from L5 to T5 in our study, and the range between L5 and T5 was allocated a sequential value between 1 and 13. The symptom duration was defined as the duration of symptoms before surgery. The acromiohumeral interval was measured on the preoperative conventional true anteroposterior radiograph of the shoulder. Adhesive capsulitis was defined as passive forward elevation of less than 100° and passive external rotation at the side of less than 30°.13,14 The overall demographic data, such as mean age, sex, and symptom
duration, showed no statistically significant differences between the study group and the control group (Table 1). The 2 groups were further divided into several subgroups according to the size of concomitant rotator cuff tear to minimize its effect, and the overall demographic data of each subgroup showed no statistically significant differences between the study group and the control group (Table 2). All the patients underwent functional evaluations such as the visual analog scale pain score, American Shoulder and Elbow Surgeons shoulder score, Constant score, rangeof-motion testing, and muscle power assessment before the operation and at 1 year, 2 years, and the last follow-up after surgery. All procedures were performed by a single senior surgeon. Four routine arthroscopic portals (anterior, posterior, lateral, and posterolateral) were used to perform rotator cuff repair, acromioplasty, and coracoplasty.15 A posterior portal was established as the
SUBCORACOID IMPINGEMENT SYNDROME TABLE 2.
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Subgroups According to Size of Concomitant Rotator Cuff Tear
Factor Large to massive rotator cuff tear subgroups No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* Subgroups with small to medium rotator cuff tear including isolated SC tear No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* No rotator cuff tear subgroups No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)*
Study
Control
8
17
57.1 ⫾ 5.8 (50-68) 6:2 57.4 ⫾ 64.7 (5.0-181.0) 6:2 6.7 ⫾ 1.4 (5.1-9.5) 5.3 ⫾ 0.5 (4.5-5.9)
60.2 ⫾ 9.0 (46-76) 6:11 51.4 ⫾ 47.5 (2.3-128.0) 15:2 5.7 ⫾ 1.8 (1.8-9.4) 5.3 ⫾ 0.6 (3.9-5.9)
12
8
58.8 ⫾ 7.7 (47-72) 6:6 60.2 ⫾ 103.0 (5.0-362.0) 10:2 8.75 ⫾ 1.3 (6.9-11.5) 4.6 ⫾ 0.8 (3.1-5.5)
59.6 ⫾ 12.1 (43-77) 1:7 37.4 ⫾ 43.1 (6.0-133.0) 7:1 8.3 ⫾ 2.1 (5.6-10.9) 5.0 ⫾ 0.6 (4.0-5.8)
3
3
48.0 ⫾ 3.6 (45-52) 1:2 64.7 ⫾ 91.7 (3.0-170.0) 1:2 6.7 ⫾ 1.2 (6.0-8.1) 5.0 ⫾ 0.4 (4.7-5.4)
50.3 ⫾ 12.1 (39-63) 2:1 25.3 ⫾ 14.8 (9.0-38.0) 1:2 8.1 ⫾ 2.0 (6.6-10.4) 4.8 ⫾ 0.5 (4.5-5.4)
P Value
.383 .069 .884 .409 .122 .889
.859 .093 .537 .803 .528 .224
.764 .456 .536 ⬎.999 .370 .661
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data to evaluate the differences between the mean values of the study group and control group (with the significance level set at P ⬍ .05). Abbreviations: AHI, acromiohumeral interval; SC, subscapularis. *Data are presented as mean ⫾ standard deviation (range).
primary viewing portal. After bursectomy, arthroscopic subacromial decompression was performed with acromioplasty and spur removal in all patients. An acromioplasty was carefully performed to maintain the continuity of the coracoacromial ligament by preserving the medial band and insertion portion of the coracoacromial ligament.16 While the surgeon was performing coracoplasty, the lateral portal was the viewing portal and the standard anterior portal was the working portal. In the arthroscopic view, the narrowed CHD was checked. In this study a “2-plane” coracoplasty was performed at the bursal side of the rotator cuff. First, the undersurface of the coracoid process was burred to make a flat plane by trimming the distal portion of the curved base of the coracoid including the spur up to 3 to 4 mm. Second, the lateral aspect was also burred by 4 to 5 mm. Finally, the angle of the burred planes underwent smoothening with a bur. Burring was performed carefully to avoid detachment
of the short head of the biceps from the coracoid process (Fig 1). All the large to massive rotator cuff tears were repaired with the suture bridge technique, and the small to medium tears were repaired with the suture bride technique or reinforcement suture.15,17 Reinforcement suture is a simple tendon-to-tendon suture without a suture anchor. Subscapularis tears were repaired with the single-row or suture bridge technique or reinforcement suture.18,19 If there was a partialthickness tear along the leading edge of the articular side with more than 50% depth of the subscapularis tendon, it was repaired in the glenohumeral joint with the single-row technique. If there was a full-thickness tear with more than 30% width of the subscapularis tendon, it was repaired in the subacromial space with the singlerow or suture bridge technique. In the case of intraarticular repair of the subscapularis tear, subscapularis repair was performed first and then acromioplasty was
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J-Y. PARK ET AL.
FIGURE 1. Arthroscopic views of 2-plane coracoplasty from the lateral portal in the left shoulder of a patient in the beach-chair position: (A) preview of coracoplasty; (B) view after resection of the undersurface of the coracoid; (C) view after resection of the lateral aspect of the coracoid; and (D) view after smoothening of the angle of the resected margin of the coracoid. The right side was medial, and the left side was lateral.
performed. After that, coracoplasty was performed, and finally, posterosuperior rotator cuff repair was performed. On the other hand, in the case of extraarticular repair of the subscapularis tear, acromioplasty was performed first and then coracoplasty was performed. Finally, rotator cuff repair including the subscapularis tendon was performed. Tenodesis or tenotomy was performed in cases with long head of the biceps dislocation, subluxation, or tear involving more than 50%.1,18 In the study group, 7 patients underwent tenodesis and 3 patients underwent tenotomy. In the control group, 7 patients underwent tenodesis and 5 patients underwent tenotomy.
Postoperatively, a shoulder-immobilizing sling with an abduction pillow was prescribed to each patient with instruction to maintain the shoulder at 30° to 40° of internal rotation and 20° of abduction. The postoperative rehabilitation was individualized according to the size of rotator cuff tear and the tissue quality of the torn rotator cuff.15 The patients without a rotator cuff tear were allowed passive forward elevation using a pulley within 1 day after surgery. If the pain was tolerable, active range of motion was started from the first postoperative day. A Wilcoxon signed rank test was used to compare the overall preoperative and postoperative data. The
SUBCORACOID IMPINGEMENT SYNDROME TABLE 3.
Overall Clinical Outcome of Study Group and Control Group
Variable Study group (23 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (28 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
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Preoperative
Postoperative (Last Follow-up)
P Value
6.9 ⫾ 2.3 (2-10) 39.2 ⫾ 16.1 (3.0-77.0) 54.2 ⫾ 11.8 (22.4-71.8) 135.0 ⫾ 29.4 (15-150) 56.3 ⫾ 21.5 (10-90) T11 (L4-T6) 2.3 ⫾ 1.5 (0.3-5.0) 4.0 ⫾ 2.0 (1.3-10.1) 5.4 ⫾ 2.7 (1.3-11.6)
1.0 ⫾ 1.6 (0-7) 90.4 ⫾ 16.5 (31.7-100) 83.7 ⫾ 11.1 (46.7-94.5) 146.7 ⫾ 11.0 (100-150) 74.1 ⫾ 11.6 (50-90) T7 (L3-T5) 6.5 ⫾ 2.0 (2.3-10.3) 7.6 ⫾ 2.2 (4.5-12.5) 8.3 ⫾ 2.9 (1.5-15.5)
⬍.001 ⬍.001 ⬍.001 .028 ⬍.001 ⬍.001 ⬍.001 ⬍.001 ⬍.001
6.5 ⫾ 2.7 (2-10) 37.4 ⫾ 19.4 (8.3-73.3) 52.0 ⫾ 10.7 (33.1-75.0) 140.0 ⫾ 17.4 (70-160) 55.9 ⫾ 25.2 (5-85) T10 (L5-T5) 2.0 ⫾ 2.1 (0.0-9.5) 3.0 ⫾ 1.7 (0.0-6.3) 3.7 ⫾ 1.8 (1.2-7.1)
0.9 ⫾ 0.9 (0-3) 88.4 ⫾ 9.4 (60.0-100) 78.5 ⫾ 6.6 (60.6-89.4) 148.4 ⫾ 6.4 (130-160) 70.9 ⫾ 13.8 (15-85) T9 (L3-T7) 5.0 ⫾ 1.3 (2.1-7.2) 5.9 ⫾ 1.6 (2.5-10.0) 6.1 ⫾ 2.2 (3.0-13.1)
⬍.001 ⬍.001 ⬍.001 .004 .004 .233 ⬍.001 ⬍.001 ⬍.001
NOTE. All values are presented as mean ⫾ standard deviation (range), except for internal rotation. This analysis was performed with the Wilcoxon signed ranks test (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; VAS, visual analog scale for pain; kgf, kilo gram force (1 kg ⫻ 9.8 m/s 2 ⫽ 9.8 N).
normally distributed data between the groups was analyzed by use of a t test for independent samples. Otherwise, a nonparametric Mann-Whitney U test was used. Statistical analysis was performed with SPSS software, version 13.0 (SPSS, Chicago, IL). The significance level was set at P ⬍ .05. RESULTS In the study group, the mean patient age was 56.8 ⫾ 7.4 years (range, 45 to 72 years) and the mean follow-up period after surgery was 32.4 ⫾ 1.0 months (range, 19 to 56 months). In the control group, the mean age was 59 ⫾ 10.3 years (range, 39 to 77 years) TABLE 4.
and the mean follow-up was 37.2 ⫾ 12.5 months (range, 24 to 63 months). After surgery, 23 cases in the study group and 28 cases in the control group showed a good functional outcome. However, in the control group, internal rotation did not improve significantly (Table 3). The cases in the study group showed more improvement in internal rotation only compared with that in the cases in the control group (P ⫽ .001) (Table 4). Although the overall functional values except for forward flexion and external rotation improved after surgery with statistical significance in the large to massive rotator cuff tear subgroup of the study group, the overall functional values except for forward flex-
Comparison of Overall Functional Outcome Between Study Group and Control Group P Value
Group
VAS Score
ASES Score
Constant Score
Forward Elevation
External Rotation
Internal Rotation
Abduction Power
External Rotation Power
Internal Rotation Power
Study v control
.631
.879
.384
.640
.413
.001
.058
.268
.369
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data between the differences in the preoperative and postoperative (last follow-up) values in the study and control groups (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; VAS, visual analog scale for pain.
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J-Y. PARK ET AL. TABLE 5.
Overall Clinical Outcome of Subgroups According to Size of Concomitant Rotator Cuff Tear
Variable Large to massive rotator cuff tear subgroups Study group (8 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (17 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Subgroups with small to medium rotator cuff tear including isolated SC tear Study group (12 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (8 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) No rotator cuff tear subgroups Study group (3 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
Preoperative
Postoperative (Last Follow-up)
P Value
7.0 ⫾ 2.5 (4-10) 37.9 ⫾ 20.1 (3.3-68.3) 50.6 ⫾ 15.8 (22.4-71.8) 120.6 ⫾ 46.2 (15-150) 55.0 ⫾ 28.8 (10-90) T11 (L4-T6) 1.9 ⫾ 1.8 (0.3-5.0) 3.7 ⫾ 1.4 (1.3-5.1) 4.5 ⫾ 2.3 (1.3-8.2)
1.6 ⫾ 2.4 (0-7) 82.3 ⫾ 25.5 (31.7-100) 78.2 ⫾ 17.4 (46.7-93.9) 141.3 ⫾ 18.1 (100-150) 70.0 ⫾ 14.1 (50-90) T9 (L3-T5) 6.4 ⫾ 2.4 (2.3-10.3) 7.1 ⫾ 2.4 (4.5-11.2) 8.1 ⫾ 3.7 (1.5-12.6)
6.4 ⫾ 2.4 (2-10) 37.8 ⫾ 18.8 (11.7-73.3) 51.6 ⫾ 9.2 (35.7-66.9) 139.4 ⫾ 20.2 (70-160) 53.5 ⫾ 27.2 (5-80) T10 (L4-T5) 1.6 ⫾ 1.5 (0.1-5.7) 3.0 ⫾ 1.8 (0.0-6.3) 3.5 ⫾ 1.8 (1.2-7.1)
0.8 ⫾ 0.9 (0-3) 90.0 ⫾ 7.7 (78.3-100) 78.9 ⫾ 5.3 (65.1-87.2) 148.2 ⫾ 6.1 (135-160) 68.5 ⫾ 16.7 (15-85) T10 (L3-T7) 5.3 ⫾ 1.1 (3.6-7.2) 6.3 ⫾ 1.7 (4.1-10.0) 6.4 ⫾ 2.3 (4.1-13.1)
⬍.001 ⬍.001 ⬍.001 .064 .020 .719 ⬍.001 .001 ⬍.001
7.0 ⫾ 1.9 (4-10) 37.2 ⫾ 10.9 (16.7-50.0) 55.1 ⫾ 8.8 (37.4-71.6) 141.7 ⫾ 11.5 (115-150) 54.6 ⫾ 18.0 (20-70) T11 (L3-T7) 2.4 ⫾ 1.3 (1.0-4.9) 4.4 ⫾ 2.4 (2.0-10.1) 6.3 ⫾ 2.9 (3.2-11.6)
0.8 ⫾ 0.9 (0-3) 93.5 ⫾ 6.7 (76.7-100) 86.0 ⫾ 4.4 (80.2-94.5) 149.6 ⫾ 1.4 (145-150) 74.2 ⫾ 10.0 (50-85) T6 (T12-T5) 6.2 ⫾ 1.9 (2.5-8.9) 7.9 ⫾ 2.4 (5.7-12.5) 8.6 ⫾ 2.8 (5.7-15.5)
.002 .002 .002 .027 .005 .002 .002 .002 .004
8.0 ⫾ 2.5 (5-10) 26.9 ⫾ 13.8 (8.3-45.0) 46.6 ⫾ 9.1 (33.1-58.9) 138.8 ⫾ 13.6 (115-150) 55.6 ⫾ 25.8 (20-85) T12 (L5-T7) 1.5 ⫾ 1.4 (0.0-3.7) 2.4 ⫾ 1.2 (0.4-4.1) 3.5 ⫾ 1.7 (1.6-7.0)
1.3 ⫾ 0.7 (0-2) 86.5 ⫾ 11.8 (60.0-100) 77.0 ⫾ 7.4 (60.6-85.4) 146.9 ⫾ 7.0 (130-150) 73.1 ⫾ 4.6 (70-80) T8 (T10-T7) 4.4 ⫾ 1.4 (2.5-5.8) 5.2 ⫾ 1.3 (2.5-6.7) 5.2 ⫾ 1.0 (3.2-6.7)
.011 .012 .012 .041 .159 .035 .018 .012 .068
6.3 ⫾ 4.0 (2-10) 50.6 ⫾ 23.4 (31.7-76.7) 60.8 ⫾ 10.0 (50.4-70.4) 146.7 ⫾ 5.8 (140-150) 66.7 ⫾ 15.3 (50-80) T9 (L2-T6) 2.8 ⫾ 2.0 (0.5-3.9) 3.3 ⫾ 2.4 (1.4-6.0) 4.1 ⫾ 1.2 (2.7-5.1)
0.0 ⫾ 0.0 (0-0) 100 ⫾ 0.0 (100-100) 89.3 ⫾ 1.3 (87.9-90.4) 150.0 ⫾ 0.0 (150-150) 85.0 ⫾ 0.0 (85-85) T6 (T9-T5) 7.8 ⫾ 1.2 (7.0-9.2) 7.7 ⫾ 1.3 (6.5-9.1) 7.7 ⫾ 1.0 (6.7-8.7)
.109 .109 .109 .317 .109 .109 .109 .109 .109
.011 .017 .017 .343 .249 .034 .012 .012 .025
SUBCORACOID IMPINGEMENT SYNDROME TABLE 5. Variable Control group (3 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
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Continued
Preoperative
Postoperative (Last Follow-up)
P Value
3.0 ⫾ 1.7 (5-9) 62.8 ⫾ 11.8 (50.0-73.3) 68.8 ⫾ 6.5 (62.1-75.0) 146.7 ⫾ 10.4 (135-155) 70.0 ⫾ 0.0 (70-70) T7 (T7-T7) 5.2 ⫾ 3.9 (2.1-9.5) 4.6 ⫾ 0.7 (4.0-5.3) 4.9 ⫾ 2.0 (3.0-7.0)
1.0 ⫾ 1.0 (0-3) 84.4 ⫾ 13.5 (70.0-96.7) 79.7 ⫾ 12.7 (65.3-89.4) 153.3 ⫾ 5.8 (150-160) 78.3 ⫾ 11.5 (65-85) T8 (T9-T7) 4.9 ⫾ 2.4 (2.1-6.5) 5.8 ⫾ 1.8 (4.0-7.5) 7.1 ⫾ 3.8 (3.0-10.4)
.180 .285 .285 .180 .276 .317 .655 .180 .180
NOTE. All values are presented as mean ⫾ standard deviation (range). This analysis was performed with the Wilcoxon signed ranks test (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; SC, subscapularis; VAS, visual analog scale for pain; kgf, kilo gram force (1 kg ⫻ 9.8 m/s2 ⫽ 9.8 N).
ion and internal rotation improved significantly in the large to massive rotator cuff tear subgroup of the control group. In the study group, the subgroup with small to medium rotator cuff tears including isolated subscapularis tears showed a significant improvement in all the functional values, whereas in the control group, the subgroup with small to medium rotator cuff tears including isolated subscapularis tears showed a significant improvement in the functional values except for external rotation and internal rotation power. Finally, in the no rotator cuff tear subgroups, the mean value of overall functional outcome improved but did not show statistical significance (Table 5). The large to massive rotator cuff tear subgroup of the study group showed a significant improvement in internal rotation after surgery compared with that in the large to massive rotator cuff tear subgroup of the control group (P ⫽ .017). On the other hand, no significant difference was seen in all the functional TABLE 6.
values between the subgroups with small to medium rotator cuff tears including isolated subscapularis tears. The no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046) compared with that in the no rotator cuff tear subgroup of the control group (Table 6). In addition, anterior-superior instability of the shoulder did not occur after surgery. DISCUSSION Subcoracoid impingement syndrome has been recognized as a cause of shoulder pain. Subcoracoid impingement is defined as a mechanical impingement of the subscapularis between the coracoid and lesser tuberosity due to subcoracoid stenosis.1,3-6,8 It is frequently associated with subacromial impingement syndrome and rotator cuff tear, especially subscapularis tear.1,6,20 There have been several reports about
Comparison of Outcome Between Subgroups of Study Group and Control Group P Value
Study v Control Large to massive tear Small to medium tear including isolated SC tear No tear
VAS Score
ASES Score
Constant Score
Forward Elevation
External Rotation
Internal Rotation
Abduction Power
External Rotation Power
Internal Rotation Power
.803
.401
.955
.394
.792
.017
.395
.880
.475
.523 .171
.816 .232
.892 .183
.776 .487
.832 .487
.954 .046
.207 .059
.435 .141
.369 .331
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data between the differences in the preoperative and postoperative (last follow-up) values in the study and control subgroups (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; SC, subscapularis; VAS, visual analog scale for pain.
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the diagnosis and treatment of subacromial impingement syndrome and rotator cuff tear including subscapularis tear.1,18,21 However, subcoracoid impingement syndrome is not a well-known diagnosis, and in addition, many orthopaedic surgeons are not yet familiar with arthroscopic coracoplasty, which has been introduced recently. There are a few studies reporting the results of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome. In 2001 Karnaugh et al.7 reported the results of arthroscopic coracoplasty in 4 patients with subcoracoid impingement syndrome. One study reported the results of 8 arthroscopic operations for combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears.1 Another study showed satisfactory results with arthroscopic coracoplasty performed in conjunction with another procedure in 13 patients with subcoracoid impingement.6 However, none of these studies included a control group with subcoracoid impingement in which arthroscopic coracoplasty was not performed, nor did they analyze all the functional values after surgery, such as internal rotation. In our study subcoracoid impingement was shown in 13% of patients with rotator cuff tears (62 of 475), and of the patients with rotator cuff tears, 23% (110 of 475) had subscapularis tears; subcoracoid impingement was found in 56% (62 of 110) of patients with subscapularis tears and in 41% (18 of 44) of patients with subacromial impingement who had no rotator cuff tears. In addition, there was 1 patient with only subcoracoid impingement. Arai et al.22 reported that among 435 shoulders undergoing arthroscopic rotator cuff repair, 119 (27.4%) showed subscapularis tears. In 2000 one study reported on subcoracoid impingement syndrome in 11 of 216 cases (5.1%) after rotator cuff surgery.23 Another study reported on the relation between a narrowed CHD and subscapularis tears.20 In that study the mean CHD in 35 cases in the torn subscapularis group was 5.0 ⫾ 1.7 mm, which was less than that in the no tear group (10.0 ⫾ 1.33 mm). These studies were closely related to our study. In our study a control group of 28 patients with subcoracoid impingement who had not undergone arthroscopic coracoplasty was included. Internal rotation in the study group increased with statistical significance after surgery more than that in the control group (P ⫽ .001). This was correlated with the pathomechanism of subcoracoid impingement, which might be induced during internal rotation, adduction, and flexion of the shoulder.1,3,4,6
To remove a source of bias arising from concomitant rotator cuff tears, we further divided the study and control groups into several subgroups according to rotator cuff tear size. The large to massive rotator cuff tear subgroup of the study group showed more improvement in internal rotation after surgery than that in the large to massive rotator cuff tear subgroup of the control group (P ⫽ .017). In addition, the no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046) compared with that in the no rotator cuff tear subgroup of the control group. Although the subgroups with small to medium tears including isolated subscapularis tears did not present a significant difference in internal rotation (P ⫽ .954), the mean internal rotation in the study group was improved compared with that in the control group. The mean value for overall functional outcome in the no rotator cuff tear subgroups was improved but did not show statistical significance. This might be because of the small case numbers in the subgroups. The large to massive rotator cuff tear and no rotator cuff tear subgroups of the study group showed a greater increase in internal rotation than that in the large to massive rotator cuff tear and no rotator cuff tear subgroups of the control group compared with the subgroups with small to medium tears including isolated subscapularis tears. This area will be studied in further research. This study had several limitations. Each subgroup included a small number of cases. Although the study group and control group were further divided into several subgroups to remove the bias arising from rotator cuff tears, the number of cases in each subgroup was too small, especially in the no rotator cuff tear subgroup. On the other hand, this study is of significant importance. First, there are few reports on arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome. Second, a control group of patients with subcoracoid impingement who had not undergone arthroscopic coracoplasty was enrolled for the first time in this study. Moreover, the overall demographic data showed no statistical difference between the study group and the control group. Third, the new technique, the 2-plane coracoplasty, was also used with satisfactory results. Finally, the decision of whether to perform an arthroscopic coracoplasty was made randomly by the operating surgeon in the operating field regardless of the patient’s data.
SUBCORACOID IMPINGEMENT SYNDROME CONCLUSIONS The overall clinical outcome of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome patients was good. In particular, a significant increase in internal rotation in the treated group was achieved in comparison with the untreated group. Internal rotation in the large to massive rotator cuff tear subgroup and in the no rotator cuff tear subgroup in the treated group improved significantly after surgery. REFERENCES 1. Lo IK, Parten PM, Burkhart SS. Combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears: An arthroscopic approach. Arthroscopy 2003;19:1068-1078. 2. Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671. 3. Dines DM, Warren RF, Inglis AE, Pavlov H. The coracoid impingement syndrome. J Bone Joint Surg Br 1990;72:314316. 4. Russo R, Togo F. The subcoracoid impingement syndrome: Clinical, semeiologic and therapeutic considerations. Ital J Orthop Traumatol 1991;17:351-358. 5. Gerber C, Terrier F, Zehnder R, Ganz R. The subcoracoid space. An anatomic study. Clin Orthop Relat Res 1987:132138. 6. Garofalo R, Conti M, Massazza G, Cesari E, Vinci E, Castagna A. Subcoracoid impingement syndrome: A painful shoulder condition related to different pathologic factors. Musculoskelet Surg 2011;95:S25-S29 (Suppl 1). 7. Karnaugh RD, Sperling JW, Warren RF. Arthroscopic treatment of coracoid impingement. Arthroscopy 2001;17:784-787. 8. Gerber C, Terrier F, Ganz R. The role of the coracoid process in the chronic impingement syndrome. J Bone Joint Surg Br 1985;67:703-708. 9. Nové-Josserand L, Boulahia A, Levigne C, Noel E, Walch G. Coraco-humeral space and rotator cuff tears. Rev Chir Orthop Reparatrice Appar Mot 1999;85:677-683 (in French). 10. DeOrio JK, Cofield RH. Results of a second attempt at surgical
11. 12.
13. 14. 15.
16. 17.
18. 19.
20. 21. 22. 23.
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repair of a failed initial rotator-cuff repair. J Bone Joint Surg Am 1984;66:563-567. Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2000;82:505515. Tan V, Moore RS Jr, Omarini L, Kneeland JB, Williams GR Jr, Iannotti JP. Magnetic resonance imaging analysis of coracoid morphology and its relation to rotator cuff tears. Am J Orthop (Belle Mead NJ) 2002;31:329-333. Park JY, Pandher DS, Moon GH, Yoo MJ, Lee ST. Comparison of surgical outcome in impingement syndrome with and without stiff shoulder. Indian J Orthop 2008;42:182-187. Hsu JE, Anakwenze OA, Warrender WJ, Abboud JA. Current review of adhesive capsulitis. J Shoulder Elbow Surg 2011; 20:502-514. Park JY, Siti HT, Keum JS, Moon SG, Oh KS. Does an arthroscopic suture bridge technique maintain repair integrity? A serial evaluation by ultrasonography. Clin Orthop Relat Res 2010;468:1578-1587. Lee TQ, Black AD, Tibone JE, McMahon PJ. Release of the coracoacromial ligament can lead to glenohumeral laxity: A biomechanical study. J Shoulder Elbow Surg 2001;10:68-72. Frank JB, ElAttrache NS, Dines JS, Blackburn A, Crues J, Tibone JE. Repair site integrity after arthroscopic transosseous-equivalent suture-bridge rotator cuff repair. Am J Sports Med 2008;36:1496-1503. Adams CR, Schoolfield JD, Burkhart SS. The results of arthroscopic subscapularis tendon repairs. Arthroscopy 2008;24: 1381-1389. Wellmann M, Wiebringhaus P, Lodde I, et al. Biomechanical evaluation of a single-row versus double-row repair for complete subscapularis tears. Knee Surg Sports Traumatol Arthrosc 2009;17:1477-1484. Richards DP, Burkhart SS, Campbell SE. Relation between narrowed coracohumeral distance and subscapularis tears. Arthroscopy 2005;21:1223-1228. Warner JJ, Higgins L, Parsons IM IV, Dowdy P. Diagnosis and treatment of anterosuperior rotator cuff tears. J Shoulder Elbow Surg 2001;10:37-46. Arai R, Sugaya H, Mochizuki T, Nimura A, Moriishi J, Akita K. Subscapularis tendon tear: An anatomic and clinical investigation. Arthroscopy 2008;24:997-1004. Suenaga N, Minami A, Kaneda K. Postoperative subcoracoid impingement syndrome in patients with rotator cuff tear. J Shoulder Elbow Surg 2000;9:275-278.
Purpose: The purpose of this study was to analyze the outcomes of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome. Methods: We compared 23 shoulders that underwent arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome with 28 shoulders that did not undergo arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome, which comprised the control group. All the shoulders had subcoracoid and subacromial impingement syndrome with or without rotator cuff tear. Subcoracoid impingement was defined as a coracohumeral distance of less than 6 mm on the preoperative magnetic resonance image with anterior shoulder pain or tenderness. The 2 groups were further divided into several subgroups according to the size of concomitant rotator cuff tear, and a comparative analysis of functional outcomes after surgery among the subgroups was performed. Results: In the 2 groups, the overall functional outcomes improved after surgery. The study group showed a significant increase in internal rotation compared with that in the control group (P ⫽ .001) at the last follow-up. The large to massive rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .017). On the other hand, no significant difference was seen in the subgroups with small to medium rotator cuff tears including isolated subscapularis tears. The no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046). Conclusions: Arthroscopic coracoplasty for subcoracoid impingement syndrome can provide a satisfactory outcome. In particular, a significant increase in internal rotation of the treated group was achieved after surgery in comparison with the untreated group, especially in the large to massive rotator cuff tear subgroup and in the no rotator cuff tear subgroup. Level of Evidence: Level III, retrospective comparative study.
S
From the Glocal Center for Shoulder & Elbow, Department of Orthopedic Surgery (J-Y.P., S-H.L., K-S.O.), and Department of Radiology (N.R.K.), Konkuk University Hospital, Konkuk University School of Medicine, Seoul; and Department of Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University Medical College(J-T.H.), Gangwon-do, South Korea. This work was supported by Konkuk University in 2011. The authors report that they have no conflicts of interest in the authorship and publication of this article. Received January 3, 2012; accepted June 4, 2012. Address correspondence to Jung-Taek Hwang, M.D., Ph.D., Department of Orthopedic Surgery, Chuncheon Sacred Heart Hospital, Hallym University Medical College, 153, Gyo-dong, Chuncheon-si, Gangwon-do, 200-704, South Korea. E-mail: drakehjt@ hanmail.net © 2012 by the Arthroscopy Association of North America 0749-8063/0126/$36.00 http://dx.doi.org/10.1016/j.arthro.2012.06.013
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ubcoracoid impingement syndrome with associated subcoracoid stenosis has been known to be a cause of shoulder pain.1-5 The pain is thought to be caused by impingement of the subscapularis between the coracoid and lesser tuberosity when an affected shoulder is flexed, adducted, and internally rotated.1,6 Although some authors have noted that subcoracoid impingement frequently causes anterior shoulder pain and tenderness, there is no effective physical examination to determine the existence of the disease. Although arthroscopic coracoplasty was introduced for the treatment of subcoracoid impingement syndrome, there have been only a few studies examining this surgical technique.1,2,6,7 In 1985 Gerber et al.8 identified the role of the coracoid process in chronic impingement syndrome. Recently, a study reported the outcome of combined
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 28, No 12 (December), 2012: pp 1766-1775
SUBCORACOID IMPINGEMENT SYNDROME arthroscopic acromioplasty, coracoplasty, and rotator cuff repair,1 and another article reported that 13 patients who underwent arthroscopic coracoplasty showed satisfactory results.6 However, these 2 studies did not include a control group in which coracoplasty was not performed for the treatment of subcoracoid impingement syndrome. The aim of this study was to analyze the functional outcomes of arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome by a comparison between the study group and the control group. In addition, we had further divided the 2 groups into several subgroups according to the size of concomitant rotator cuff tear and compared the outcome among the subgroups to remove bias arising from rotator cuff tears. We hypothesized that arthroscopic coracoplasty was necessary for the treatment of subcoracoid impingement syndrome along with the treatment of concomitant diseases. METHODS All procedures described in this study were approved by the international review board of our hospital, and all patients gave written informed consent to participate in this study. Between July 31, 2006, and July 30, 2009, we performed 475 arthroscopic repairs or debridements of rotator cuff tears showing fraying at the least. Among them, 110 rotator cuff tears included subscapularis tears. Forty-four arthroscopic subacromial decompressions for patients who had subacromial impingement and did not have rotator cuff tears were performed. In addition, 1 patient with only subcoracoid impingement syndrome underwent an arthroscopic coracoplasty. Among the 520 patients, 81 who had a coracohumeral distance (CHD) of less than 6 mm with anterior shoulder pain or tenderness were diagnosed as having subcoracoid impingement syndrome.1,6,9 Arthroscopic coracoplasty was performed for 37 patients among the 81 with subcoracoid impingement. The decision of whether to perform an arthroscopic coracoplasty was made randomly by the operating surgeon during the operation regardless of demographic or operative data, such as age, rotator cuff tear, and CHD. We classified a rotator cuff tear with a length smaller than 1 cm as small, a tear measuring 1 to 3 cm as medium, a tear measuring 3 to 5 cm as large, and a tear measuring larger than 5 cm as massive.10 In addition, a massive tear was defined as a detachment of at least 2 entire tendons.11 CHD was defined as the shortest distance between the humeral head and the coracoid process on an axial cut on preoperative mag-
1767
netic resonance imaging (MRI).9,12 Preoperative MRI was performed with the patient in the supine position with the upper extremity in its anatomic position. For the cases in the study group, the inclusion criteria were as follows: (1) a preoperative MRI study was available, (2) the patient underwent an arthroscopic acromioplasty and coracoplasty, (3) the CHD was less than 6 mm, and (4) the patient presented with anterior shoulder pain or tenderness. Some patients were excluded for the following reasons: (1) the patient had follow-up of less than 24 months, (2) the patient simultaneously underwent an operation for concomitant instability (SLAP lesion or Bankart lesion) or osteosynthesis of os acromiale, (3) the patient had incomplete repairs because of severe retraction or poor tissue quality of the torn rotator cuff, (4) the patient underwent anterior capsulotomy for adhesive capsulitis, (5) the patient had a history of previous shoulder operation, (6) the patient underwent open rotator cuff repairs, (7) the patient had calcific tendinitis, (8) the patient had a concomitant nerve injury around the shoulder, and (9) the patient had a traumatic rotator cuff tear. Among the 37 patients with subcoracoid impingement syndrome who underwent arthroscopic coracoplasty, the case with only subcoracoid impingement who underwent arthroscopic coracoplasty was excluded based on the inclusion criteria and 14 cases were excluded based on the exclusion criteria. The remaining 23 patients, who had undergone arthroscopic coracoplasty during the period, were included in the study group. Among them, the cases with rotator cuff tears had subscapularis pathology of fraying of the leading edge at the least. There were 3 cases without rotator cuff tears. On the other hand, the 44 candidates in the control group were selected based on the previously mentioned inclusion criteria except for the criterion that the shoulder had undergone an arthroscopic coracoplasty. There were 29 cases with a CHD of less than 6 mm and subscapularis pathology more than fraying of the subscapularis tendon. Among them, 4 cases were excluded based on the previously mentioned exclusion criteria. There were 15 cases without rotator cuff tears having a CHD of less than 6 mm and that underwent only acromioplasty. Among them, 12 cases were excluded in a similar manner. In the end, the remaining 28 cases among the 44 patients were enrolled in the control group. Among all the 51 patients of the study and control groups, the cases with rotator cuff tears had subscapularis pathology of fraying of the leading edge at the least.
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J-Y. PARK ET AL. TABLE 1.
Demographic and Operative Characteristics
Factor
Study
Control
No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* Operative data Concomitant rotator cuff tear Small to medium Large to massive Isolated SC No tear SC lesion Debridement Repair LHB pathology Absence Fraying (⬍50%) Partial tear (⬎50%) Subluxation Dislocation Tear with subluxation or dislocation Spontaneous rupture ADCR due to AC arthrosis
23
28
56.8 ⫾ 7.4 (45-72) 13:10 59.8 ⫾ 86.1 (3.0-362.0) 17:6 7.8 ⫾ 1.7 (5.1-11.5) 4.9 ⫾ 0.7 (3.1-5.9)
59.0 ⫾ 10.3 (39-77) 9:19 44.6 ⫾ 43.8 (2.3-133.0) 23:5 6.7 ⫾ 2.2 (1.8-10.9) 5.2 ⫾ 0.6 (3.9-5.9)
8 8 4 3
6 17 2 3
4 16
13 12
9 2 5 1 1 3 2 3
13 2 8 3 3 1 1 4
P Value
.400 .083 .616 .481 .060 .117
NOTE. Fraying was defined as a long head of the biceps lesion of less than 50%. Tenodesis or tenotomy was performed in cases with long head of the biceps dislocation, subluxation, or tear involving more than 50%. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data to evaluate the differences between the mean values of the study group and control group (with the significance level set at P ⬍ .05). Abbreviations: AC, acromioclavicular joint; ADCR, arthroscopic distal clavicle resection; AHI, acromiohumeral interval; LHB, long head of biceps; SC, subscapularis. *Data are presented as mean ⫾ standard deviation (range).
Power analysis indicated that a total sample size of 40 patients (20 patients in each cohort) would provide a statistical power of 90% with a 2-sided ␣ level of .05 to detect significant differences in internal rotation, assuming an effect size of 1.1 (mean difference, 3.3; SD, 2.9). This was based on the mean and standard deviation of internal rotation observed in a pilot study of 20 patients. Internal rotation was measured in an active manner from L5 to T5 in our study, and the range between L5 and T5 was allocated a sequential value between 1 and 13. The symptom duration was defined as the duration of symptoms before surgery. The acromiohumeral interval was measured on the preoperative conventional true anteroposterior radiograph of the shoulder. Adhesive capsulitis was defined as passive forward elevation of less than 100° and passive external rotation at the side of less than 30°.13,14 The overall demographic data, such as mean age, sex, and symptom
duration, showed no statistically significant differences between the study group and the control group (Table 1). The 2 groups were further divided into several subgroups according to the size of concomitant rotator cuff tear to minimize its effect, and the overall demographic data of each subgroup showed no statistically significant differences between the study group and the control group (Table 2). All the patients underwent functional evaluations such as the visual analog scale pain score, American Shoulder and Elbow Surgeons shoulder score, Constant score, rangeof-motion testing, and muscle power assessment before the operation and at 1 year, 2 years, and the last follow-up after surgery. All procedures were performed by a single senior surgeon. Four routine arthroscopic portals (anterior, posterior, lateral, and posterolateral) were used to perform rotator cuff repair, acromioplasty, and coracoplasty.15 A posterior portal was established as the
SUBCORACOID IMPINGEMENT SYNDROME TABLE 2.
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Subgroups According to Size of Concomitant Rotator Cuff Tear
Factor Large to massive rotator cuff tear subgroups No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* Subgroups with small to medium rotator cuff tear including isolated SC tear No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)* No rotator cuff tear subgroups No. Demographic data Age (yr)* Sex (male-female) Symptom duration (mo)* Side of involvement (dominant-nondominant) AHI (mm)* CHD (mm)*
Study
Control
8
17
57.1 ⫾ 5.8 (50-68) 6:2 57.4 ⫾ 64.7 (5.0-181.0) 6:2 6.7 ⫾ 1.4 (5.1-9.5) 5.3 ⫾ 0.5 (4.5-5.9)
60.2 ⫾ 9.0 (46-76) 6:11 51.4 ⫾ 47.5 (2.3-128.0) 15:2 5.7 ⫾ 1.8 (1.8-9.4) 5.3 ⫾ 0.6 (3.9-5.9)
12
8
58.8 ⫾ 7.7 (47-72) 6:6 60.2 ⫾ 103.0 (5.0-362.0) 10:2 8.75 ⫾ 1.3 (6.9-11.5) 4.6 ⫾ 0.8 (3.1-5.5)
59.6 ⫾ 12.1 (43-77) 1:7 37.4 ⫾ 43.1 (6.0-133.0) 7:1 8.3 ⫾ 2.1 (5.6-10.9) 5.0 ⫾ 0.6 (4.0-5.8)
3
3
48.0 ⫾ 3.6 (45-52) 1:2 64.7 ⫾ 91.7 (3.0-170.0) 1:2 6.7 ⫾ 1.2 (6.0-8.1) 5.0 ⫾ 0.4 (4.7-5.4)
50.3 ⫾ 12.1 (39-63) 2:1 25.3 ⫾ 14.8 (9.0-38.0) 1:2 8.1 ⫾ 2.0 (6.6-10.4) 4.8 ⫾ 0.5 (4.5-5.4)
P Value
.383 .069 .884 .409 .122 .889
.859 .093 .537 .803 .528 .224
.764 .456 .536 ⬎.999 .370 .661
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data to evaluate the differences between the mean values of the study group and control group (with the significance level set at P ⬍ .05). Abbreviations: AHI, acromiohumeral interval; SC, subscapularis. *Data are presented as mean ⫾ standard deviation (range).
primary viewing portal. After bursectomy, arthroscopic subacromial decompression was performed with acromioplasty and spur removal in all patients. An acromioplasty was carefully performed to maintain the continuity of the coracoacromial ligament by preserving the medial band and insertion portion of the coracoacromial ligament.16 While the surgeon was performing coracoplasty, the lateral portal was the viewing portal and the standard anterior portal was the working portal. In the arthroscopic view, the narrowed CHD was checked. In this study a “2-plane” coracoplasty was performed at the bursal side of the rotator cuff. First, the undersurface of the coracoid process was burred to make a flat plane by trimming the distal portion of the curved base of the coracoid including the spur up to 3 to 4 mm. Second, the lateral aspect was also burred by 4 to 5 mm. Finally, the angle of the burred planes underwent smoothening with a bur. Burring was performed carefully to avoid detachment
of the short head of the biceps from the coracoid process (Fig 1). All the large to massive rotator cuff tears were repaired with the suture bridge technique, and the small to medium tears were repaired with the suture bride technique or reinforcement suture.15,17 Reinforcement suture is a simple tendon-to-tendon suture without a suture anchor. Subscapularis tears were repaired with the single-row or suture bridge technique or reinforcement suture.18,19 If there was a partialthickness tear along the leading edge of the articular side with more than 50% depth of the subscapularis tendon, it was repaired in the glenohumeral joint with the single-row technique. If there was a full-thickness tear with more than 30% width of the subscapularis tendon, it was repaired in the subacromial space with the singlerow or suture bridge technique. In the case of intraarticular repair of the subscapularis tear, subscapularis repair was performed first and then acromioplasty was
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J-Y. PARK ET AL.
FIGURE 1. Arthroscopic views of 2-plane coracoplasty from the lateral portal in the left shoulder of a patient in the beach-chair position: (A) preview of coracoplasty; (B) view after resection of the undersurface of the coracoid; (C) view after resection of the lateral aspect of the coracoid; and (D) view after smoothening of the angle of the resected margin of the coracoid. The right side was medial, and the left side was lateral.
performed. After that, coracoplasty was performed, and finally, posterosuperior rotator cuff repair was performed. On the other hand, in the case of extraarticular repair of the subscapularis tear, acromioplasty was performed first and then coracoplasty was performed. Finally, rotator cuff repair including the subscapularis tendon was performed. Tenodesis or tenotomy was performed in cases with long head of the biceps dislocation, subluxation, or tear involving more than 50%.1,18 In the study group, 7 patients underwent tenodesis and 3 patients underwent tenotomy. In the control group, 7 patients underwent tenodesis and 5 patients underwent tenotomy.
Postoperatively, a shoulder-immobilizing sling with an abduction pillow was prescribed to each patient with instruction to maintain the shoulder at 30° to 40° of internal rotation and 20° of abduction. The postoperative rehabilitation was individualized according to the size of rotator cuff tear and the tissue quality of the torn rotator cuff.15 The patients without a rotator cuff tear were allowed passive forward elevation using a pulley within 1 day after surgery. If the pain was tolerable, active range of motion was started from the first postoperative day. A Wilcoxon signed rank test was used to compare the overall preoperative and postoperative data. The
SUBCORACOID IMPINGEMENT SYNDROME TABLE 3.
Overall Clinical Outcome of Study Group and Control Group
Variable Study group (23 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (28 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
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Preoperative
Postoperative (Last Follow-up)
P Value
6.9 ⫾ 2.3 (2-10) 39.2 ⫾ 16.1 (3.0-77.0) 54.2 ⫾ 11.8 (22.4-71.8) 135.0 ⫾ 29.4 (15-150) 56.3 ⫾ 21.5 (10-90) T11 (L4-T6) 2.3 ⫾ 1.5 (0.3-5.0) 4.0 ⫾ 2.0 (1.3-10.1) 5.4 ⫾ 2.7 (1.3-11.6)
1.0 ⫾ 1.6 (0-7) 90.4 ⫾ 16.5 (31.7-100) 83.7 ⫾ 11.1 (46.7-94.5) 146.7 ⫾ 11.0 (100-150) 74.1 ⫾ 11.6 (50-90) T7 (L3-T5) 6.5 ⫾ 2.0 (2.3-10.3) 7.6 ⫾ 2.2 (4.5-12.5) 8.3 ⫾ 2.9 (1.5-15.5)
⬍.001 ⬍.001 ⬍.001 .028 ⬍.001 ⬍.001 ⬍.001 ⬍.001 ⬍.001
6.5 ⫾ 2.7 (2-10) 37.4 ⫾ 19.4 (8.3-73.3) 52.0 ⫾ 10.7 (33.1-75.0) 140.0 ⫾ 17.4 (70-160) 55.9 ⫾ 25.2 (5-85) T10 (L5-T5) 2.0 ⫾ 2.1 (0.0-9.5) 3.0 ⫾ 1.7 (0.0-6.3) 3.7 ⫾ 1.8 (1.2-7.1)
0.9 ⫾ 0.9 (0-3) 88.4 ⫾ 9.4 (60.0-100) 78.5 ⫾ 6.6 (60.6-89.4) 148.4 ⫾ 6.4 (130-160) 70.9 ⫾ 13.8 (15-85) T9 (L3-T7) 5.0 ⫾ 1.3 (2.1-7.2) 5.9 ⫾ 1.6 (2.5-10.0) 6.1 ⫾ 2.2 (3.0-13.1)
⬍.001 ⬍.001 ⬍.001 .004 .004 .233 ⬍.001 ⬍.001 ⬍.001
NOTE. All values are presented as mean ⫾ standard deviation (range), except for internal rotation. This analysis was performed with the Wilcoxon signed ranks test (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; VAS, visual analog scale for pain; kgf, kilo gram force (1 kg ⫻ 9.8 m/s 2 ⫽ 9.8 N).
normally distributed data between the groups was analyzed by use of a t test for independent samples. Otherwise, a nonparametric Mann-Whitney U test was used. Statistical analysis was performed with SPSS software, version 13.0 (SPSS, Chicago, IL). The significance level was set at P ⬍ .05. RESULTS In the study group, the mean patient age was 56.8 ⫾ 7.4 years (range, 45 to 72 years) and the mean follow-up period after surgery was 32.4 ⫾ 1.0 months (range, 19 to 56 months). In the control group, the mean age was 59 ⫾ 10.3 years (range, 39 to 77 years) TABLE 4.
and the mean follow-up was 37.2 ⫾ 12.5 months (range, 24 to 63 months). After surgery, 23 cases in the study group and 28 cases in the control group showed a good functional outcome. However, in the control group, internal rotation did not improve significantly (Table 3). The cases in the study group showed more improvement in internal rotation only compared with that in the cases in the control group (P ⫽ .001) (Table 4). Although the overall functional values except for forward flexion and external rotation improved after surgery with statistical significance in the large to massive rotator cuff tear subgroup of the study group, the overall functional values except for forward flex-
Comparison of Overall Functional Outcome Between Study Group and Control Group P Value
Group
VAS Score
ASES Score
Constant Score
Forward Elevation
External Rotation
Internal Rotation
Abduction Power
External Rotation Power
Internal Rotation Power
Study v control
.631
.879
.384
.640
.413
.001
.058
.268
.369
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data between the differences in the preoperative and postoperative (last follow-up) values in the study and control groups (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; VAS, visual analog scale for pain.
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J-Y. PARK ET AL. TABLE 5.
Overall Clinical Outcome of Subgroups According to Size of Concomitant Rotator Cuff Tear
Variable Large to massive rotator cuff tear subgroups Study group (8 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (17 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Subgroups with small to medium rotator cuff tear including isolated SC tear Study group (12 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) Control group (8 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf) No rotator cuff tear subgroups Study group (3 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
Preoperative
Postoperative (Last Follow-up)
P Value
7.0 ⫾ 2.5 (4-10) 37.9 ⫾ 20.1 (3.3-68.3) 50.6 ⫾ 15.8 (22.4-71.8) 120.6 ⫾ 46.2 (15-150) 55.0 ⫾ 28.8 (10-90) T11 (L4-T6) 1.9 ⫾ 1.8 (0.3-5.0) 3.7 ⫾ 1.4 (1.3-5.1) 4.5 ⫾ 2.3 (1.3-8.2)
1.6 ⫾ 2.4 (0-7) 82.3 ⫾ 25.5 (31.7-100) 78.2 ⫾ 17.4 (46.7-93.9) 141.3 ⫾ 18.1 (100-150) 70.0 ⫾ 14.1 (50-90) T9 (L3-T5) 6.4 ⫾ 2.4 (2.3-10.3) 7.1 ⫾ 2.4 (4.5-11.2) 8.1 ⫾ 3.7 (1.5-12.6)
6.4 ⫾ 2.4 (2-10) 37.8 ⫾ 18.8 (11.7-73.3) 51.6 ⫾ 9.2 (35.7-66.9) 139.4 ⫾ 20.2 (70-160) 53.5 ⫾ 27.2 (5-80) T10 (L4-T5) 1.6 ⫾ 1.5 (0.1-5.7) 3.0 ⫾ 1.8 (0.0-6.3) 3.5 ⫾ 1.8 (1.2-7.1)
0.8 ⫾ 0.9 (0-3) 90.0 ⫾ 7.7 (78.3-100) 78.9 ⫾ 5.3 (65.1-87.2) 148.2 ⫾ 6.1 (135-160) 68.5 ⫾ 16.7 (15-85) T10 (L3-T7) 5.3 ⫾ 1.1 (3.6-7.2) 6.3 ⫾ 1.7 (4.1-10.0) 6.4 ⫾ 2.3 (4.1-13.1)
⬍.001 ⬍.001 ⬍.001 .064 .020 .719 ⬍.001 .001 ⬍.001
7.0 ⫾ 1.9 (4-10) 37.2 ⫾ 10.9 (16.7-50.0) 55.1 ⫾ 8.8 (37.4-71.6) 141.7 ⫾ 11.5 (115-150) 54.6 ⫾ 18.0 (20-70) T11 (L3-T7) 2.4 ⫾ 1.3 (1.0-4.9) 4.4 ⫾ 2.4 (2.0-10.1) 6.3 ⫾ 2.9 (3.2-11.6)
0.8 ⫾ 0.9 (0-3) 93.5 ⫾ 6.7 (76.7-100) 86.0 ⫾ 4.4 (80.2-94.5) 149.6 ⫾ 1.4 (145-150) 74.2 ⫾ 10.0 (50-85) T6 (T12-T5) 6.2 ⫾ 1.9 (2.5-8.9) 7.9 ⫾ 2.4 (5.7-12.5) 8.6 ⫾ 2.8 (5.7-15.5)
.002 .002 .002 .027 .005 .002 .002 .002 .004
8.0 ⫾ 2.5 (5-10) 26.9 ⫾ 13.8 (8.3-45.0) 46.6 ⫾ 9.1 (33.1-58.9) 138.8 ⫾ 13.6 (115-150) 55.6 ⫾ 25.8 (20-85) T12 (L5-T7) 1.5 ⫾ 1.4 (0.0-3.7) 2.4 ⫾ 1.2 (0.4-4.1) 3.5 ⫾ 1.7 (1.6-7.0)
1.3 ⫾ 0.7 (0-2) 86.5 ⫾ 11.8 (60.0-100) 77.0 ⫾ 7.4 (60.6-85.4) 146.9 ⫾ 7.0 (130-150) 73.1 ⫾ 4.6 (70-80) T8 (T10-T7) 4.4 ⫾ 1.4 (2.5-5.8) 5.2 ⫾ 1.3 (2.5-6.7) 5.2 ⫾ 1.0 (3.2-6.7)
.011 .012 .012 .041 .159 .035 .018 .012 .068
6.3 ⫾ 4.0 (2-10) 50.6 ⫾ 23.4 (31.7-76.7) 60.8 ⫾ 10.0 (50.4-70.4) 146.7 ⫾ 5.8 (140-150) 66.7 ⫾ 15.3 (50-80) T9 (L2-T6) 2.8 ⫾ 2.0 (0.5-3.9) 3.3 ⫾ 2.4 (1.4-6.0) 4.1 ⫾ 1.2 (2.7-5.1)
0.0 ⫾ 0.0 (0-0) 100 ⫾ 0.0 (100-100) 89.3 ⫾ 1.3 (87.9-90.4) 150.0 ⫾ 0.0 (150-150) 85.0 ⫾ 0.0 (85-85) T6 (T9-T5) 7.8 ⫾ 1.2 (7.0-9.2) 7.7 ⫾ 1.3 (6.5-9.1) 7.7 ⫾ 1.0 (6.7-8.7)
.109 .109 .109 .317 .109 .109 .109 .109 .109
.011 .017 .017 .343 .249 .034 .012 .012 .025
SUBCORACOID IMPINGEMENT SYNDROME TABLE 5. Variable Control group (3 cases) VAS score ASES score Constant score Forward flexion (°) External rotation (°) Internal rotation (°) Abduction power (kgf) External rotation power (kgf) Internal rotation power (kgf)
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Continued
Preoperative
Postoperative (Last Follow-up)
P Value
3.0 ⫾ 1.7 (5-9) 62.8 ⫾ 11.8 (50.0-73.3) 68.8 ⫾ 6.5 (62.1-75.0) 146.7 ⫾ 10.4 (135-155) 70.0 ⫾ 0.0 (70-70) T7 (T7-T7) 5.2 ⫾ 3.9 (2.1-9.5) 4.6 ⫾ 0.7 (4.0-5.3) 4.9 ⫾ 2.0 (3.0-7.0)
1.0 ⫾ 1.0 (0-3) 84.4 ⫾ 13.5 (70.0-96.7) 79.7 ⫾ 12.7 (65.3-89.4) 153.3 ⫾ 5.8 (150-160) 78.3 ⫾ 11.5 (65-85) T8 (T9-T7) 4.9 ⫾ 2.4 (2.1-6.5) 5.8 ⫾ 1.8 (4.0-7.5) 7.1 ⫾ 3.8 (3.0-10.4)
.180 .285 .285 .180 .276 .317 .655 .180 .180
NOTE. All values are presented as mean ⫾ standard deviation (range). This analysis was performed with the Wilcoxon signed ranks test (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; SC, subscapularis; VAS, visual analog scale for pain; kgf, kilo gram force (1 kg ⫻ 9.8 m/s2 ⫽ 9.8 N).
ion and internal rotation improved significantly in the large to massive rotator cuff tear subgroup of the control group. In the study group, the subgroup with small to medium rotator cuff tears including isolated subscapularis tears showed a significant improvement in all the functional values, whereas in the control group, the subgroup with small to medium rotator cuff tears including isolated subscapularis tears showed a significant improvement in the functional values except for external rotation and internal rotation power. Finally, in the no rotator cuff tear subgroups, the mean value of overall functional outcome improved but did not show statistical significance (Table 5). The large to massive rotator cuff tear subgroup of the study group showed a significant improvement in internal rotation after surgery compared with that in the large to massive rotator cuff tear subgroup of the control group (P ⫽ .017). On the other hand, no significant difference was seen in all the functional TABLE 6.
values between the subgroups with small to medium rotator cuff tears including isolated subscapularis tears. The no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046) compared with that in the no rotator cuff tear subgroup of the control group (Table 6). In addition, anterior-superior instability of the shoulder did not occur after surgery. DISCUSSION Subcoracoid impingement syndrome has been recognized as a cause of shoulder pain. Subcoracoid impingement is defined as a mechanical impingement of the subscapularis between the coracoid and lesser tuberosity due to subcoracoid stenosis.1,3-6,8 It is frequently associated with subacromial impingement syndrome and rotator cuff tear, especially subscapularis tear.1,6,20 There have been several reports about
Comparison of Outcome Between Subgroups of Study Group and Control Group P Value
Study v Control Large to massive tear Small to medium tear including isolated SC tear No tear
VAS Score
ASES Score
Constant Score
Forward Elevation
External Rotation
Internal Rotation
Abduction Power
External Rotation Power
Internal Rotation Power
.803
.401
.955
.394
.792
.017
.395
.880
.475
.523 .171
.816 .232
.892 .183
.776 .487
.832 .487
.954 .046
.207 .059
.435 .141
.369 .331
NOTE. This analysis was performed with the Mann-Whitney U test or t test for independent samples according to the normality of data between the differences in the preoperative and postoperative (last follow-up) values in the study and control subgroups (with the significance level set at P ⬍ .05). Abbreviations: ASES, American Shoulder and Elbow Surgeons; SC, subscapularis; VAS, visual analog scale for pain.
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J-Y. PARK ET AL.
the diagnosis and treatment of subacromial impingement syndrome and rotator cuff tear including subscapularis tear.1,18,21 However, subcoracoid impingement syndrome is not a well-known diagnosis, and in addition, many orthopaedic surgeons are not yet familiar with arthroscopic coracoplasty, which has been introduced recently. There are a few studies reporting the results of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome. In 2001 Karnaugh et al.7 reported the results of arthroscopic coracoplasty in 4 patients with subcoracoid impingement syndrome. One study reported the results of 8 arthroscopic operations for combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears.1 Another study showed satisfactory results with arthroscopic coracoplasty performed in conjunction with another procedure in 13 patients with subcoracoid impingement.6 However, none of these studies included a control group with subcoracoid impingement in which arthroscopic coracoplasty was not performed, nor did they analyze all the functional values after surgery, such as internal rotation. In our study subcoracoid impingement was shown in 13% of patients with rotator cuff tears (62 of 475), and of the patients with rotator cuff tears, 23% (110 of 475) had subscapularis tears; subcoracoid impingement was found in 56% (62 of 110) of patients with subscapularis tears and in 41% (18 of 44) of patients with subacromial impingement who had no rotator cuff tears. In addition, there was 1 patient with only subcoracoid impingement. Arai et al.22 reported that among 435 shoulders undergoing arthroscopic rotator cuff repair, 119 (27.4%) showed subscapularis tears. In 2000 one study reported on subcoracoid impingement syndrome in 11 of 216 cases (5.1%) after rotator cuff surgery.23 Another study reported on the relation between a narrowed CHD and subscapularis tears.20 In that study the mean CHD in 35 cases in the torn subscapularis group was 5.0 ⫾ 1.7 mm, which was less than that in the no tear group (10.0 ⫾ 1.33 mm). These studies were closely related to our study. In our study a control group of 28 patients with subcoracoid impingement who had not undergone arthroscopic coracoplasty was included. Internal rotation in the study group increased with statistical significance after surgery more than that in the control group (P ⫽ .001). This was correlated with the pathomechanism of subcoracoid impingement, which might be induced during internal rotation, adduction, and flexion of the shoulder.1,3,4,6
To remove a source of bias arising from concomitant rotator cuff tears, we further divided the study and control groups into several subgroups according to rotator cuff tear size. The large to massive rotator cuff tear subgroup of the study group showed more improvement in internal rotation after surgery than that in the large to massive rotator cuff tear subgroup of the control group (P ⫽ .017). In addition, the no rotator cuff tear subgroup of the study group showed a significant increase in internal rotation (P ⫽ .046) compared with that in the no rotator cuff tear subgroup of the control group. Although the subgroups with small to medium tears including isolated subscapularis tears did not present a significant difference in internal rotation (P ⫽ .954), the mean internal rotation in the study group was improved compared with that in the control group. The mean value for overall functional outcome in the no rotator cuff tear subgroups was improved but did not show statistical significance. This might be because of the small case numbers in the subgroups. The large to massive rotator cuff tear and no rotator cuff tear subgroups of the study group showed a greater increase in internal rotation than that in the large to massive rotator cuff tear and no rotator cuff tear subgroups of the control group compared with the subgroups with small to medium tears including isolated subscapularis tears. This area will be studied in further research. This study had several limitations. Each subgroup included a small number of cases. Although the study group and control group were further divided into several subgroups to remove the bias arising from rotator cuff tears, the number of cases in each subgroup was too small, especially in the no rotator cuff tear subgroup. On the other hand, this study is of significant importance. First, there are few reports on arthroscopic coracoplasty for the treatment of subcoracoid impingement syndrome. Second, a control group of patients with subcoracoid impingement who had not undergone arthroscopic coracoplasty was enrolled for the first time in this study. Moreover, the overall demographic data showed no statistical difference between the study group and the control group. Third, the new technique, the 2-plane coracoplasty, was also used with satisfactory results. Finally, the decision of whether to perform an arthroscopic coracoplasty was made randomly by the operating surgeon in the operating field regardless of the patient’s data.
SUBCORACOID IMPINGEMENT SYNDROME CONCLUSIONS The overall clinical outcome of arthroscopic coracoplasty in the treatment of subcoracoid impingement syndrome patients was good. In particular, a significant increase in internal rotation in the treated group was achieved in comparison with the untreated group. Internal rotation in the large to massive rotator cuff tear subgroup and in the no rotator cuff tear subgroup in the treated group improved significantly after surgery. REFERENCES 1. Lo IK, Parten PM, Burkhart SS. Combined subcoracoid and subacromial impingement in association with anterosuperior rotator cuff tears: An arthroscopic approach. Arthroscopy 2003;19:1068-1078. 2. Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671. 3. Dines DM, Warren RF, Inglis AE, Pavlov H. The coracoid impingement syndrome. J Bone Joint Surg Br 1990;72:314316. 4. Russo R, Togo F. The subcoracoid impingement syndrome: Clinical, semeiologic and therapeutic considerations. Ital J Orthop Traumatol 1991;17:351-358. 5. Gerber C, Terrier F, Zehnder R, Ganz R. The subcoracoid space. An anatomic study. Clin Orthop Relat Res 1987:132138. 6. Garofalo R, Conti M, Massazza G, Cesari E, Vinci E, Castagna A. Subcoracoid impingement syndrome: A painful shoulder condition related to different pathologic factors. Musculoskelet Surg 2011;95:S25-S29 (Suppl 1). 7. Karnaugh RD, Sperling JW, Warren RF. Arthroscopic treatment of coracoid impingement. Arthroscopy 2001;17:784-787. 8. Gerber C, Terrier F, Ganz R. The role of the coracoid process in the chronic impingement syndrome. J Bone Joint Surg Br 1985;67:703-708. 9. Nové-Josserand L, Boulahia A, Levigne C, Noel E, Walch G. Coraco-humeral space and rotator cuff tears. Rev Chir Orthop Reparatrice Appar Mot 1999;85:677-683 (in French). 10. DeOrio JK, Cofield RH. Results of a second attempt at surgical
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