|Year : 2018 | Volume
| Issue : 1 | Page : 26-31
Evaluation of Short-Term Outcomes of Arthroscopic Bursectomy Without Acromioplasty for Shoulder Impingement Syndrome With Type I and Type II Acromia
Nishit Bhatnagar1, Rajat Gupta2, Deepak Gupta1, Anurag Tiwari3, Yugal Karkhur4
1 Department of Orthopedics, Maulana Azad Medical College and Lok Nayak Hospital, New Delhi, India
2 Department of Orthopaedics, Fortis Hospital, Mohali, Punjab, India
3 Department of Orthopedics, All India Institute of Medical Sciences, Bhopal, Madhya Pradesh
4 Department of Orthopaedics, Max Smart Hospital, New Delhi, India
|Date of Web Publication||27-Mar-2018|
7 Godavari Apartments, Alaknanda, New Delhi 110019
Source of Support: None, Conflict of Interest: None
Purpose: To evaluate the efficacy of arthroscopic bursectomy in impingement syndrome with type I and type II acromia. Materials and Methods: Patients of shoulder impingement syndrome that did not improve on 6 weeks of conservative treatment were included. Patients with hooked acromion and full thickness rotator cuff tear were excluded based on radiological and ultrasonographic assessment. Arthroscopic bursectomy was performed in the selected patients. Constant–Murley score was used for evaluation preoperatively and at fixed intervals till 12 weeks postoperatively. Wilcoxon signed ranks test was performed for statistical analysis of nonparametric data. Results: The average age of patients was 40.5 years. The majority of the patients were males (70%) with involvement of dominant side, and seven had involvement of the nondominant side. Type I acromion and type II acromion were seen in 10 patients each. Ultrasound was able to detect all patients who had rotator cuff tear (20%), as confirmed during diagnostic arthroscopy. Type II acromion was found in three out of these four patients. All parameters of the Constant–Murley score worsened at 2 weeks postoperatively but showed statistically significant improvement during subsequent follow-up. Eight patients (40%) were rated as having excellent result, four patients (20%) as having good result, four (20%) as having fair result. These 16 patients (80%) were satisfied with the overall result. Four patients had a partial thickness rotator cuff tear. Out of these, three had poor outcome and one had fair outcome. Conclusions: Satisfactory outcomes were achieved in 80% of our patients. However, four patients in our study did not show encouraging results, thereby stressing the role of extrinsic factors also in the pathogenesis of impingement syndrome. Hence we recommend arthroscopic busrectomy for patients with shoulder impingement syndrome after exhausting conservative treatment, excluding a hooked acromion and rotator cuff tear. Level of Evidence: Level II − prospective interventional study.
Keywords: Arthroscopic bursectomy, impingement syndrome, shoulder
|How to cite this article:|
Bhatnagar N, Gupta R, Gupta D, Tiwari A, Karkhur Y. Evaluation of Short-Term Outcomes of Arthroscopic Bursectomy Without Acromioplasty for Shoulder Impingement Syndrome With Type I and Type II Acromia. MAMC J Med Sci 2018;4:26-31
|How to cite this URL:|
Bhatnagar N, Gupta R, Gupta D, Tiwari A, Karkhur Y. Evaluation of Short-Term Outcomes of Arthroscopic Bursectomy Without Acromioplasty for Shoulder Impingement Syndrome With Type I and Type II Acromia. MAMC J Med Sci [serial online] 2018 [cited 2018 Dec 16];4:26-31. Available from: http://www.mamcjms.in/text.asp?2018/4/1/26/228661
| Introduction|| |
Impingement syndrome, also called painful arc syndrome, occurs when the rotator cuff tendons become irritated and inflamed as they pass through the subacromial space. This results in pain most commonly in an arc between 60–120°, weakness, and loss of movement. The pain is referred to the insertion of deltoid muscle. There are two schools of thought regarding the etiology of impingement syndrome. Extrinsic theory best defined as impingement syndrome, implicates trauma to the tendons between the humeral head and coracoacromial arch as being important in causation of tendon tearing and hence forms the rationale of doing acromioplasty. Intrinsic theory claims that symptoms are a result of tensile forces caused by degenerative tendinopathy of rotator cuff leading to subacromial inflammatory reaction. Tendon degeneration and eventual tearing are fostered by the intrinsic biology of the tendon structure, and they point to the anatomic and microvascular studies, showing that the changes occur most commonly in the areas of hypovascularity. This forms the basis of offering bursectomy as a treatment option.
Bigliani et al., identified three acromial shapes from cadaver studies flat (17%), curved (43%) and hooked (40%). The third type is most commonly associated with painful arc syndrome. Arthroscopic acromioplasty can produce pain relief and functional improvement in recalcitrant cases but is technically difficult. Bursectomy without acromioplasty has shown excellent results in a few studies. But due to paucity of studies evaluating the efficacy of arthroscopic bursectomy on Indian population, patients are treated surgically with a combined procedure, which may be an unnecessary overkill. The aim of our study was to evaluate the efficacy of arthroscopic bursectomy in impingement syndrome with type I and type II acromia. There were no conflicts of interests of any of the authors.
| Materials and Methods|| |
The study was conducted at a tertiary level referral center in India from September 2013 to December 2014. Patients having shoulder symptoms of painful arc, restricted active range of motion (ROM) or night pain for more than 6 weeks duration were screened and evaluated in detail [Figure 1]. Patients with positive Hawkins–Kennedy sign, Neer impingement sign, Neer impingement test and full passive ROM were classified as impingement syndrome. They underwent further clinical testing, radiological imaging (antero-posterior and scapular-Y views) and ultrasonographic assessment to exclude patients with gleno-humeral instability, type III acromion, full thickness rotator cuff tear and acromioclavicular joint arthritis. Conservative therapy in the form of analgesics, subacromial steroid injection, physiotherapy alone or in combination was given for 6 weeks before surgical intervention. Patients that did not improve were included in the study for surgical treatment. Appropriate written informed consent was obtained from the patients. Preoperative evaluation of shoulder function was performed by Constant–Murley Scale (CMS).
|Figure 1: Methodology of selection of cases. ROM = range of motioin, AC = acromioclavicular|
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Patients were operated in a beach chair position. The arm was draped free so that full extension, external and internal rotation was possible. A pillow was placed along the medial border of scapula to rotate the torso internally (away from surgeon) since this gave an outlet view of shoulder. The bony landmarks, scapular spine, acromial borders, acromioclavicular joint, and clavicle and coracoid processes were identified and marked. In the study, a single surgeon, with more than 15 years experience in arthroscopic surgeries, operated upon all patients. A standard posterior portal was established at the posterior soft spot approximately at 2 cm medial and 2–3 cm distal to the posterolateral angle of the acromion. After diagnostic arthroscopy of shoulder joint, the scope was redirected to subacromial space. A lateral portal was established to access the subacromial space. A subacromial pump and 1.5% glycine were used for distension of the joint. Anterior portal was also established in some cases by “inside-out” technique if required. Thorough debridement of the subacromial bursa was performed using a motorized shaver. After bursal excision, hemostasis was achieved by electrocautery probe. A catheter was placed in the subacromial space through the posterior portal for postoperative analgesia.
Arm was kept in cuff and collar sling. Through the subacromial catheter 10 ml of 0.25% bupivacaine was instilled every 12 h. Cold therapy in the form of ice packs was given for the first 24 h, and the catheter was removed after 48 h. Pendulum exercises, passive ROM exercises in the form of supine forward flexion, and supine passive external rotation exercises with arm at that side were started on the first postoperative day. Cuff and collar sling were discontinued as soon as the patient felt comfortable. Active ROM exercises were started as soon as the patient became pain free. Once resisted manual testing of the operated shoulder muscles became painless, active strengthening exercises were initiated.
Postoperative evaluation using CMS was performed at 2, 4, 8, and 16 weeks postoperatively. The CMS is based on a 100-point scale. Subjective characteristics are responsible for 35 points. An absence of pain is worth 15 points, whereas functional characteristics such as ability to work can be awarded as many as 25 points. Objective measurements are awarded a maximum of 65 points, with 40 points possible for the ROM and 25 points possible for strength. Final results were graded with normalized 100 point Constant shoulder score as excellent (90–100), good (80–89), fair (70–79), or poor (<70). Score greater than or equal to 70 was considered satisfactory. Two independent orthopedic surgeons did postoperative assessment. The average score of their assessment was taken to be the result of the assessment. Wilcoxon signed ranks test was used to analyze nonparametric data and significance level was taken as P < 0.05.
| Results|| |
During the period of study, 50 patients of impingement syndrome were diagnosed. Fourteen were discovered to have type III acromion, four had full thickness supraspinatus tear and two had acromioclavicular joint arthritis. These had to be excluded from the study. Out of the rest, nine patients had symptomatic improvement following 6 weeks of conservative treatment and one patient refused surgical treatment [Figure 2]. Thus, 20 patients were finally included in the study and underwent arthroscopic bursectomy.
|Figure 2: Exclusion of patients to arrive at final study population. AC = acromioclavicular|
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The age of patients ranged from 21 to 60 years, with an average age of 40.5 years. The majority of the patients were males (70%). Of the 20 patients, one had bilateral involvement, 11 had involvement of the dominant side and seven had involvement of the nondominant side. Ten patients were involved in moderately heavy work, one in heavy manual work and the rest had a sedentary lifestyle. Type I acromion and type II acromion were seen in 10 patients each.
Ultrasonographic examination revealed partial thickness tear in 20% of the patients. Ultrasound was able to detect all patients who had rotator cuff tear, as confirmed during diagnostic arthroscopy. Type II acromion was found in three out of these four patients. Duration of symptoms ranged from 2.5 months to 2 years, with average duration being 12.3 months.
The results of treatment were assessed using the Constant–Murley score at 2, 4, 8, and 16 weeks [Table 1]. Postoperatively, mean pain score worsened at 2 weeks but subsequently there was statistically significant sequential improvement. Similarly score of activities of daily living also did not improve at 2 weeks, but subsequent improvement was statistically significant. Positioning of arm, forward flexion, abduction, internal rotation, and power also followed the trend of deterioration at 2 weeks followed subsequently by statistically significant improvement. Mean external rotation score, after deterioration at 2 weeks returned to preoperative status at 4 weeks and then subsequently showed statistically significant improvement.
|Table 1: Mean values of components of Constant–Murley score before and after surgery|
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The lowest preoperative total Constant–Murley score was 34, which dropped to as low as 23 at 2 weeks, but showed improvement of up to 100 at 16 weeks postoperatively [Table 2]. Final Constant–Murley score at 16 weeks was used for assigning the overall results. Eight patients (40%) were rated as having excellent result, four patients (20%) as having good result, four (20%) as having fair result. These 16 patients (80%) were satisfied with the overall result.
|Table 2: Range and mean values of total Constant–Murley score before and after surgery|
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The four unsatisfied patients also had significant pain relief but did not have significant improvement in power. Subjectively, one patient believed that the arm was even weaker than before. This patient had type II acromion with partial thickness tear and was noncompliant on rehabilitative regime in the postoperative period.
Four patients had a partial thickness rotator cuff tear. Out of these, three had poor outcome and one had fair outcome.
| Discussion|| |
Classically, the subacromial impingement syndrome has been divided into stages, with stage I representing edema and hemorrhage; stage II representing fibrosis and tendonitis; and stage III representing bone spurs and tendon rupture. However, Neer has placed all tears in stage III. Olsewski and Depew and Fukuda et al. have placed partial thickness tears in a modified stage II. We would tend to agree that stage I involvement should include not only the edema and hemorrhage but also chronic fibrosis and tendonitis; stage II would include demonstrable evidence of tendon damage in the form of partial thickness tendon tearing; and stage III would define full thickness tendon tearing. This modification of the classic staging classification would more closely reflect in our minds the treatment decision-making process, because almost all of those in stage I according to this modification would be best treated by conservative methods. For those in stage II with partial thickness tendon tearing, surgery would be a better treatment option if the symptoms were severe, and nonoperative measures had been exhausted. Then in stage III or full thickness tendon tears, surgical treatment would be a definite treatment option.
The exact staging and diagnosis of the patients with impingement syndrome can be challenging; the symptoms and signs of the rotator cuff disease are similar throughout the entire spectrum of impingement. Park et al. showed that most of the clinical tests for shoulder were sensitive but not specific and suggested using a combination of tests to increase the specificity. A combination of Hawkins–Kennedy impingement sign, painful arc sign, and infraspinatus test yield the best post-test probability for any degree of impingement syndrome., A combination of painful arc sign, drop arm sign, and infraspinatus muscle test produced the best post-test probability for full thickness tears.,
Although conventional plain radiography offers little diagnostic help, we observed that the shape of acromion, as seen on supraspinatus outlet view, correlates with the presence of impingement syndrome. Adjunctive imaging techniques such as arthrography, ultrasonography or magnetic resonance imaging (MRI) can be used to provide further information. Ultrasound is less helpful in diagnosing small tears and its overall accuracy in delineating lesions of the rotator cuff is less than that of other modalities. But in experienced hands, ultrasonography can reveal not only the integrity of the rotator cuff but also the thickness of its various components tendons.
Naqvi et al. compared ultrasonography and MRI for the detection of cuff tears in 91 patients. They concluded that ultrasonography was comparable to MRI for the detection of full thickness tear. Middleton et al. and Stiles and Otte also concluded that the accuracy of ultrasound in experienced hands was at least as good as that of MRI. In our study ultrasonography was used to evaluate the patient preoperatively. Ultrasonography was able to pick up two of the three partial thickness tears, confirmed by MRI and preoperative findings. Ultrasonography also picked up all of the cases of sub-acromial bursitis.
The most common conservative interventional modalities include modification of activity, the use of nonsteroidal anti-inflammatory medications, subacromial injections of steroids, and physical therapy programs. Morrison reported the results of nonoperative treatment in a study of 616 patients who had isolated subacromial impingement syndrome. He concluded that patients who had a type-I acromion were more likely to have a satisfactory result. If nonoperative treatment fails to reduce symptoms, operative intervention may be indicated.
Neer recommended anterior acromioplasty along with rotator cuff repair as the procedure of choice. The approach however, included detachment of part of deltoid leading to a protracted rehabilitation time. Arthroscopic techniques have given comparable outcomes but the procedures are technically demanding. Adolfsson and Lysholm reported unsatisfactory outcome in 33% of seventy-nine patients who were managed with arthroscopic acromioplasty for the treatment of subacromial impingement syndrome. Schneider et al. reported unsatisfactory outcome of arthroscopic acromioplasty in 23% of the 52 patients who had stage I or stage II impingement syndrome. Roye et al. recently reported unsatisfactory results in 20% patients of arthroscopic acromioplasty who had stage II impingement syndrome. The reason cited by the above researchers and also seconded by Jobe’s theory is that glenohumeral instability causes secondary impingement and hence poor outcomes. Hawkins et al. reported even worse results of arthroscopic acromioplasty. Only 48% patients had satisfactory outcomes in their series.
Ellman first described arthroscopic subacromial decompression as an alternative to open acromioplasty in 1987. He reported satisfactory outcome in 88% of the forty-nine patients who underwent arthroscopic subacromial decompression. Six out of 49 patients had an unsatisfactory result. Two of these patients had had a previous open acromioplasty and two had either a massive tear of the rotator cuff. Gartsman et al. performed the first anatomical study to compare this technique with open acromioplasty and suggested that arthroscopic subacromial decompression is at least as good as the open technique for the treatment of impingement.
Gartsman later reported satisfactory outcome in 85% of patients who underwent arthroscopic subacromial decompression in a clinical study of 126 patients (129 shoulders) who had stage II impingement. The only factor that appeared to be associated with the unsatisfactory outcome was patient’s workers’ compensation status. Esch et al. also obtained similar rates of satisfactory outcome (82%). Budoff et al. also reported excellent or good results of arthroscopic debridement without acromioplasty for partial thickness rotator cuff tears. Henkus et al. in their prospective randomized study showed comparable good clinical outcomes of arthroscopic subacromial bursectomy alone and debridement of the subacromial bursa followed by acromioplasty.
Assessment of shoulder function is crucial to effective outcomes research for shoulder conditions. The commonly used assessment tools are University of California at Los Angeles (UCLA) shoulder scoring scale, the Constant–Murley shoulder scoring scale and the American shoulder and elbow surgeons scoring., Advantages of the CMS include its widespread use and prolonged existence, allowing for comparisons across procedure and time.
In our study, we removed the subacromial bursa arthroscopically thereby removing the stimulus causing degenerative tendinopathy. The overall results of the surgery were encouraging because 80% patients were subjectively better and satisfied with the outcome of surgery. Both the unsatisfied patients had type II acromion and partial thickness tear, thereby supporting the fact that some extrinsic mechanisms are also responsible for the impingement and some additional procedure in the form of acromioplasty was required in these cases. These patients were unsatisfied with the lack of improvement in power, but the patients had significant pain relief.
In our study, all the comparative parameters deteriorated at 2 weeks of follow-up, which was mainly because of apprehension and inadequate postoperative physiotherapy compliance on the part of the patient. On the reinforcement of importance of rehabilitative exercises at 2 weeks, patients showed improvement in all parameters at 4 weeks as compared to their status at 2 weeks and reached approximately to their preoperative status at 4 weeks. From there on all patients showed serial improvement in all aspects of their function, both subjective and objective.
A consistent pathologic finding was the prominent anterior acromion in patients with rotator cuff tear. Preoperatively the acromion was evaluated using the supraspinatus outlet view, a lateral view in the scapular plane with 5–10° of caudal tilt. In our study also, out of the four patients who had partial thickness tear, three had type II acromion.
Our study was limited by a small sample size due to the short period during which the study was conducted. A larger sample size would have increased the power of the study and added weightage to the results obtained. Follow-up duration of 4 months was again limited by the time period available for the study. MRI was not a part of the study protocol, although it has become the prime imaging investigation for impingement and rotator cuff pathologies. However, this limitation was partly negated by the fact that all four patients who were detected to have rotator cuff tear arthroscopically had already been diagnosed with the same by ultrasonography.
| Conclusions|| |
The present study evaluates the role of arthroscopic bursectomy in the management of impingement syndrome with type I and type II acromia. We found that impingement syndrome was more common in the fifth decade of life in males and was more common in the dominant shoulder. Satisfactory outcomes were achieved in 80% of our patients. These findings support the intrinsic theory in the pathogenesis of impingement syndrome. However, four patients in our study did not show encouraging results, thereby stressing the role of extrinsic factors also in the pathogenesis of impingement syndrome. Hence we recommend arthroscopic bursectomy for patients with shoulder impingement syndrome after exhausting conservative treatment, excluding a hooked acromion and rotator cuff tear.
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| References|| |
Neer CS 2nd. Impingement lesions. Clin Orthop Relat Res 1983;173:70-7.
Michener LA, McClure PW, Karduna AR. Anatomical and biomechanical mechanisms of subacromial impingement syndrome. Clin Biomech (Bristol, Avon) 2003;18:369-79.
Chansky HA, Iannotti JP. The vascularity of the rotator cuff. Clin Sports Med 1991;10:807-22.
Sano H, Ishii H, Trudel G, Uhthoff HK. Histologic evidence of degeneration at the insertion of 3 rotator cuff tendons: A comparative study with human cadaveric shoulders. J Shoulder Elbow Surg 1999;8:574-9.
Bigliani LU, Morrison DS, April EW. The morphology of the acromion and its relationship to cuff tears. Orthop Trans 1986;10:228.
Bigliani LU, Ticker JB, Flatow EL, Soslowsky LJ, Mow VC. The relationship of acromial architecture to rotator cuff disease. Clin Sports Med 1991;10:823-38.
Budoff JE, Rodin D, Ochiai D, Nirschl RP. Arthroscopic rotator cuff debridement without decompression for the treatment of tendinosis. Arthroscopy 2005;21:1081-9.
Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop 1987;214:160-4.
Neer CS 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: A preliminary report. J Bone Joint Surg Am 1972;54:41-50.
Olsewski JM, Depew AD. Arthrscopic subacromial decompression and rotator cuff debridement for stage II and stage III impingement. Arthroscopy 1994;10:61-8.
Fukuda H, Mikasa M, Ogawa K, Yamanaka K, Hamada K. The partial thickness tear of the rotator cuff. Orthop Trans 1983;7:137.
Park HB, Yokota A, Gill HS, El Rassi G, McFarland EG. Diagnostic accuracy of clinical tests for the different degrees of subacromial impingement syndrome. J Bone Joint Surg Am 2005;87:1446-55.
Calis M, Akgun K, Birtane M, Karacan I, Calis H, Tuzun F. Diagnostic values of clinical diagnostic tests in subacromial impingement syndrome. Ann Rheum Dis 2000;59:44-7.
Leroux JL, Thomas E, Bonnet F, Blotman F. Diagnostic value of clinical tests for shoulder impingement syndrome. Rev Rhum Engl Ed 1995;62:423-8.
Lenza M, Buchbinder R, Takwoingi Y, Johnston RV, Hanchard NC, Faloppa F. Magnetic resonance imaging, magnetic resonance arthrography and ultrasonography for assessing rotator cuff tears in people with shoulder pain for whom surgery is being considered. Cochrane Database Syst Rev 2013;24:CD009020.
Read JW, Perko M. Shoulder ultrasound: Diagnostic accuracy for impingement syndrome, rotator cuff tear, and biceps tendon pathology. J Shoulder Elbow Surg 1998;7:264-71.
Naqvi GA, Jadaan M, Harrington P. Accuracy of ultrasonography and magnetic resonance imaging for detection of full thickness rotator cuff tears. Int J Shoulder Surg 2009;3:94-7.
] [Full text]
Middleton WD, Edelstein G, Reinus WR, Melson GL, Totty WG, Murphy WA. Sonographic detection of rotator cuff tears. Am J Roentgenol 1985;144:349-53.
Stiles RG, Otte MT. Imaging of the shoulder. Radiology 1993;188:603-13.
Morrison DS. Conservative management of partial-thickness rotator cuff lesions. In: Burkhead WZ Jr, editor. Rotator Cuff Disorders. Baltimore: Williams & Wilkins; 1996. p. 249-57.
Adolfsson L, Lysholm J. Results of arthroscopic acromioplasty related to rotator cuff lesions. Int Orthop 1993;17:228-31.
Schneider T, Strauss JM, Hoffstetter I, Jerosch J. Shoulder joint stability after arthroscopic subacromial decompression. Arch Orthop Trauma Surg 1994;113:129-33.
Roye RP, Grana WA, Yates CK. Arthroscopic subacromial decompression: Two- to seven-year follow-up. Arthroscopy 1995;11:301-6.
Jobe CM, Pink MM, Jobe FW, Shaffer B. Anterior shoulder instability, impingement, and rotator cuff tear: Theories and concepts. In: Jobe FW, editor. Operative Techniques in Upper Extremity Sports Injuries. St. Louis, MO: CV Mosby; 1996. p. 164-76.
Hawkins RJ, Plancher KD, Saddemi SR, Brezenoff LS, Moor JT. Arthroscopic subacromial decompression. J Shoulder Elbow Surg 2001;10:225-30.
Ellman H. Diagnosis and treatment of incomplete rotator cuff tears. Clin Orthop Relat Res 1990;64-74.
Gartsman GM, Blair ME, Noble PC, Bennett JB, Tullos HS. Arthroscopic subacromial decompression. An anatomical study. Am J Sports Med 1988;16:48-50.
Gartsman GM. Arthroscopic acromioplasty for lesions of the rotator cuff. J Bone Joint Surg Am 1990;72:169-80.
Esch JC, Ozerkis LR, Helgager JA, Kane N, Lilliott N. Arthroscopic subacromial decompression: Results according to the degree of rotator cuff tear. Arthroscopy 1988;4:241-9.
Budoff JE, Nirschl RP, Guidi EJ. Débridement of partial-thickness tears of the rotator cuff without acromioplasty. Long-term follow-up and review of the literature. J Bone Joint Surg Am 1998;80:733-48.
Henkus HE, de Witte PB, Nelissen RG, Brand R, van Arkel ER. Bursectomy compared with acromioplasty in the management of subacromial impingement syndrome: A prospective randomised study. J Bone Joint Surg Br 2009;91:504-10.
Amstutz HC, Sew Hoy AL, Clarke IC. UCLA anatomic total shoulder arthroplasty. Clin Orthop Relat Res 1981;155:7-20.
Richards RR, An KN, Bigliani LU, Friedman RJ, Gartsman GM, Gristina AG et al.
A standardized method for the assessment of shoulder function. J Shoulder Elbow Surg 1994;3:347-52.
Wylie JD, Beckmann JT, Granger E, Tashjian RZ. Functional outcomes assessment in shoulder surgery. World J Orthop 2014;5:623-33.
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[Table 1], [Table 2]