The effect of preemptive middle glenohumeral ligament release in arthroscopic rotator cuff repair to reduce postoperative stiffness: A retrospective comparative study

DOI: https://doi.org/10.21203/rs.3.rs-2514420/v1

Abstract

Background: This study aimed to evaluate the efficacy of preemptive middle glenohumeral ligament (MGHL) release in arthroscopic rotator cuff repair (ARCR) to reduce postoperative stiffness.

Methods: Patients who underwent ARCR were enrolled and allocated into two groups retrospectively: the preemptive MGHL release group (n=44) and the preemptive MGHL non-release group (n=42). Clinical outcomes were assessed and compared between the two groups, including the range of motion, Japanese Orthopedic Association Shoulder Score, Constant Shoulder Score, and the University of California, Los Angeles Score preoperatively and 3 months, 6 months, and 12 months postoperatively and complications. The integrity of the repaired tendon was assessed at the 12-month follow-up using magnetic resonance imaging.

Results: There were no significant differences between the groups in all range of motion and all functional scores at any of the assessed time points. There was also no significant difference in the healing failure rate 2.3% in the preemptive MGHL group and 2.4% in the preemptive MGHL non-release group (p=.97), and postoperative stiffness was 2.3% in the preemptive MGHL group and 7.1% in the preemptive MGHL non-release group (p=.28). There was no postoperative instability in both group.

Conclusion: ARCR effectively facilitates the recovery of range of motion and function in patients with a rotator cuff tear. However, preemptive MGHL release could not be an effective method to reduce postoperative stiffness.

Introduction

Although arthroscopic rotator cuff repair (ARCR) is a minimally invasive procedure, postoperative stiffness may still develop and lead to less functional outcomes (13). Surgeons have made several efforts to prevent postoperative stiffness; however, the efforts remain controversial and lack consensus (49).

The main causes of shoulder stiffness have been reported to be the thickening of the coracohumeral ligament (CHL) and joint capsule in the rotator interval (RI) or obliteration of the fat triangle between the coracoid process and the CHL (810). Postoperative stiffness has a greater component of intra-articular causes, predominantly capsular fibrosis and adhesions arising from the bodily reactions to the damaged glenohumeral ligaments (3, 11, 12). Nevertheless, there have been few studies on intraoperative surgical procedures to reduce postoperative stiffness after ARCR in patients with no preoperative stiffness (8, 9).

Although the RI capsule containing the CHL is considered the predominant area of the stiffed shoulder (810), it is difficult to gain a full ROM after the release of only the RI capsule based on our clinical experience. Holloway et al. reported that wide arthroscopic capsule release is necessary for regaining the full ROM in a stiffed shoulder, which indicates that the capsule, including the glenohumeral ligaments, is one of the main causes of the restricted ROM (13). We hypothesized that patients who underwent ARCR with preemptive middle glenohumeral ligament (MGHL) release would experience reduced postoperative stiffness than patients who underwent ARCR without MGHL release. To our knowledge, there has been only one study on whether preemptive MGHL release as an intraoperative procedure would reduce postoperative stiffness (8). Therefore, this study aimed to evaluate the efficacy and safety of MGHL release in ARCR to reduce postoperative stiffness.

Materials And Methods

Inclusion and Exclusion Criteria

Between January 2018 and May 2021, 280 consecutive patients underwent ARCR at our hospital. We enrolled patients who met the following inclusion criteria: presence of complete rotator cuff tears, including the supraspinatus tendon as verified by preoperative magnetic resonance imaging (MRI); experience with complete rotator cuff repair; and follow-up for at least one year after ARCR with an evaluation of successful repair using MRI. The exclusion criteria were as follows: irreparable rotator cuff tears, experience with partial repair, preoperative shoulder stiffness, and revision surgery. Patients were divided into two groups: ARCR without MGHL release from January 2018 to December 2019 (MGHL- group) and ARCR with MGHL release from January 2020 to May 2021 (MGHL + group). The tear size of the rotator cuff was evaluated using MRI. We measured the longitudinal and transverse dimensions of the tear on preoperative MRI along the oblique coronal and sagittal planes, respectively (14). The tear size was categorized as small (< 1 cm), medium (1–3 cm), large (3–5 cm), or massive (> 5 cm), according to Cofield (15). We defined shoulder stiffness as limited shoulder ROM (passive forward flexion less than or equal to 120°and/or external rotation less than or equal to 30°), as previously described (16). Patients who met these criteria were considered to have preoperative stiffness. A total of 280 ARCRs were performed during the study period. After the exclusion of 194 patients, the remaining 86 patients were included in this study (Fig. 1).

Surgical Technique

All operations were performed uniformly under general anesthesia and in a beach chair position by a single skilled surgeon. The arthroscope was inserted through the posterior portal, and a standard anterior portal was made a working portal in the RI capsule. After visualization, all hypertrophic synovial tissues were cleared as needed. In the MGHL + group, MGHL was released from the undersurface of the glenoid using a radiofrequency device through the anterior portal (Fig. 2). Then, the CHL release was performed until the base of the coracoid process and the coracoacromial ligament was exposed in both groups. Following the removal of the subacromial bursal tissue and bone spur, a standard ARCR was performed using suture anchors. The number of anchors was decided according to the size of the tear and repair configuration in the suture-bridge repair. In patients who also required the subscapularis tendon repair, the subscapularis tendon was repaired using the suture anchor by a single row technique. Tenotomy or tenodesis was performed in case of a biceps long head lesion.

All patients received the same postoperative rehabilitation (17). The shoulder was immobilized for four weeks for small-to-medium tears and six weeks for large-to-massive tears using an abduction brace (Global Sling; COSMOS, Sapporo, Japan). The elbow, wrist, and fingers exercises were started immediately after surgery. Passive forward flexion exercises were initiated from the day after surgery. An active-assisted motion exercise was initiated at four weeks for small-to-medium tears and six weeks for large-to-massive tears postoperatively. An active motion was allowed at six weeks for small-to-medium tears and eight weeks for large-to-massive tears postoperatively. A strengthening exercise program was allowed at eight weeks for small-to-medium tears and 12 weeks for large-to-massive tears postoperatively. Rehabilitation was performed at least three months after surgery with the assistance of a physical therapist. Full return to sports or heavy labor was allowed after six months.

Clinical Outcomes

Clinical outcomes were evaluated between the two groups, including the ROM, Japanese Orthopedic Association (JOA) Shoulder Score, Constant Shoulder Score, and the University of California, Los Angeles (UCLA) Score preoperatively and 3 months, 6 months, and 12 months postoperatively and complications. Active ROM (forward flexion, ER, and internal rotation [IR]) were measured with the scapular in a fixed position. IR was defined as the highest vertebral body the patient could reach with the thumb of the affected arm. IR was scored in accordance with the JOA shoulder score as follows: above Th12, 6 points; above L5, 4 points; at the buttocks, 2 points; and below the buttocks, 0 points. The integrity of the repaired tendon was assessed at the 12-month follow-up using MRI. Repair integrity after ARCR was classified into five categories according to the Sugaya classification using oblique coronal, oblique sagittal, and transverse views of T2-weighted images (18). Types 4 and 5 were considered retears using this classification system.

Statistical Analysis

All statistical analyses were performed using the SPSS software (ver.18.0, SPSS Inc, Chicago, IL, USA). The chi-squared test was used to analyze categorical variables to compare patients’ gender ratio, affected side, tear size, the number of rotator cuff tears, the procedure of biceps long head, the presence of diabetes mellitus, and complications between two groups. Student’s t-test was used to compare age, ROM, and functional scores between the two groups, and the paired t-test was used to compare these variables between two consecutive periods in each group. Statistical significance was set at p < 0.05.

Results

A total of 280 ARCRs were performed during the study period. After excluding 194 patients, the remaining 86 were included in this study. The mean age of all patients was 62.2 ± 9.4 years and the mean follow-up period was 15.6 ± 3.5 months. Forty-four patients underwent ARCR with MGHL release (MGHL + group; 32 males and 12 females, mean age was 62.8 ± 8.9 years), and 42 underwent ARCR without MGHL release (MGHL- group; 23 males and 19 females, mean age was 61.7 ± 9.9 years).

The demographic characteristics of the patients are presented in Table 1. There were no significant differences in gender, mean age, affected side, tear size, the number of rotator cuff tears, the procedure of biceps long head, the presence of diabetes mellitus, ROM, and functional scores between the two groups. There were no significant differences between the groups in all ROM and all functional scores at any of the assessed time points (Table 2, 3). There was also no significant difference in the healing failure rate 2.3% in the MGHL + group and 2.4% in the MGHL- group (p = .97), and postoperative stiffness was 2.3% in the MGHL + group and 7.1% in the MGHL- group (p = .28) There was no postoperative instability in both group. (Table 4).

Table 1

Patient’s demographics at baseline

Variables

MGHL + group

MGHL- group

P-value

Number of shoulders

44

42

 

Male / Female (n)

32/12

23/19

.08

Age (years)

62.8 ± 8.9

61.7 ± 9.9

.28

Affected side (right /left) (n)

29/15

21/21

.14

Tear size (n)

   

.95

below medium-sized

41

39

 

above larger-sized

3

3

 

The number of rotator cuff tear (n)

   

.39

SSP only

36

31

 

SSP + ISP

1

1

 

SSP + SSC

6

8

 

SSP + SSC + ISP

1

2

 

Procedure of biceps long head (n)

   

.27

tenotomy

21

20

 

tenodesis

5

4

 

nothing

18

16

 

The presence of diabetes mellitus (n)

8

13

.17

SSP: Supraspinatus
ISP: Infraspinatus
SSC: Subscapularis

Table 2

Comparison of preoperative and postoperative ROM

Variables

MGHL + group

MGHL- group

P-value

ROM

     

forward flexion (°)

     

Preop

157.9 ± 12.6

160.7 ± 15.6

.18

POD 3M

139.5 ± 20.3

142.1 ± 20.4

.27

POD 6M

160.5 ± 17.4

162.1 ± 13.3

.32

POD 12M

167.2 ± 11.2

169.2 ± 10.4

.19

ER (°)

     

Preop

52.9 ± 8.5

55.4 ± 6.7

.07

POD 3M

37.3 ± 10.1

40.2 ± 13.6

.14

POD 6M

50.3 ± 8.8

52.9 ± 11.1

.11

POD 12M

55.3 ± 7.4

56.9 ± 8.3

.18

IR (point)

     

Preop

4.0 ± 1.8

4.2 ± 1.7

.31

POD 3M

3.3 ± 1.5

3.2 ± 1.5

.43

POD 6M

4.5 ± 1.4

4.6 ± 1.2

.33

POD 12M

5.5 ± 0.9

5.6 ± 0.8

.18

Table 3

Comparison of preoperative and postoperative functional scores

Variables

MGHL + group

MGHL- group

P-value

JOA score (point)

     

Preop

64.5 ± 11.9

68.3 ± 12.5

.08

POD 3M

78.1 ± 5.6

80.1 ± 6.1

.07

POD 6M

86 ± 8.1

88.2 ± 7.8

.09

POD 12M

94 ± 5.3

94.2 ± 8.1

.42

Constant Shoulder score (point)

     

Preop

61.1 ± 11

63.1 ± 11.9

.25

POD 3M

78.1 ± 5.6

80.1 ± 6.1

.26

POD 6M

80.6 ± 8.1

83 ± 7.8

.08

POD 12M

89.5 ± 5.9

89.4 ± 8.3

.46

UCLA score (point)

     

Preop

18.5 ± 3.7

19.8 ± 4.7

.16

POD 3M

22.6 ± 2.5

21.9 ± 2.7

.10

POD 6M

26.3 ± 3.5

26.4 ± 3.5

.44

POD 12M

30.7 ± 3.2

29.8 ± 3.6

.11

Table 4

Complications

 

MGHL + group

MGHL- group

P-value

Re-tear

1 (2.3%)

1 (2.4%)

.97

Postoperative stiffness

1 (2.3%)

3 (7.1%)

.28

Postoperative instability

0

0

1.0

Discussion

The main finding of this study was that the MGHL + group did not experience more reduced postoperative stiffness than the MGHL- group. Postoperative shoulder stiffness is a prevalent adverse event after ARCR that is associated with major limitations in daily activities and prolonged rehabilitaion (6, 19, 20).

The incidence of postoperative stiffness after ARCR has been reported to range from 4.91–32.7% and, if left untreated, may lead to substantial morbidity (19, 21, 22). The exact etiology of postoperative stiffness has not been established yet; capsular contractures and postsurgical adhesion to the surrounding soft tissues are considered responsible for causing postoperative stiffness (20). Preoperative risk factors for developing postoperative shoulder stiffness after ARCR have been reported to be preoperative shoulder stiffness, age less than 50 years, workers compensation, diabetes, hypothyroidism, and coexisting diagnosis of calcific tendonitis or adhesive capsulitis (6, 19, 23). Intraoperative risk factors reported include single-tendon tears, partial articular-sided tears, and concomitant labral repair (19). Several studies have reported that associated procedures, including long head of biceps tenotomy or tenodesis, acromioplasty, capsulotomy, and glenohumeral/acromioclavicular osteoarthritis, could also increase the rate of postoperative shoulder stiffness (2426).

The CHL has been reported to originate from the base and horizontal limb of the coracoid process, enclosing the subscapularis, supraspinatus, and infraspinatus tendons (27). In this study, it enveloped vaster areas of the subscapularis than previously reported (28). A thickened CHL at the RI has been well known to be one of the most specific manifestations of a stiff shoulder and the primary restraint against ER (29). Neer et al. reported that ER could be increased up to an average of 32° when sectioning CHL (30). Harryman et al. reported that the sectioning of the RI increased the ROM of the shoulder (31). Tsai et al. reported that arthroscopic extended RI release for patients with refractory adhesive capsulitis improved the shoulder ROM (32). Furthermore, Jazrawi et al. examined the effects of arthroscopic RI closure and found that imbrication of the RI resulted in a loss of approximately 11° of ER (33). Mologne et al. also reported that arthroscopic RI closure significantly reduced ER in both neutral and abducted arm positions (34). These studies suggested that the RI is closely associated with the ROM of the shoulder.

If postoperative stiffness is not resolved, additional procedures such as manipulation under anesthesia or arthroscopic capsular release could be considered (5, 7, 35). Although many trials have been conducted on these clinical factors, only a few studies have investigated intraoperative procedures to prevent postoperative stiffness (8, 9). Kim et al. reported that preemptive RI release in ARCR presented significantly better ROM and functional scores at postoperative 3 months than in the RI non-release group (8). However, the functional scores and ROM were not significantly different between the two groups at postoperative 6 or 12 months or the final follow-up. Park et al. reported that concomitant CHL release in ARCR presented significantly better ER in the early postoperative period than in the CHL non-release group, which was effective in patients with a small-to-medium-sized rotator cuff tear (9). They concluded that CHL release in ARCR can be used as a selective procedure to prevent postoperative stiffness in patients that may benefit from this procedure with decreased preoperative ER compared to the normal side.

Capsulectomy is considered to be an effective procedure for patients with preoperative stiffness (32, 36, 37). Moreover, as previously mentioned, it has been reported that the capsule, including the glenohumeral ligaments, is one of the main causes of a restricted ROM (13). Therefore, we hypothesized that preemptive MGHL release could prevent postoperative stiffness after ARCR. However, there were no significant differences between the groups in all ROM and all functional scores at any of the assessed time points.

There is no consensus in the literature regarding the optimal extent of a glenohumeral ligament release. Bowen et al., in their cadaveric study, showed that releasing the superior glenohumeral ligament, the MGHL, the RI, and the CHL resulted in increased ER of the shoulder joint. Releasing the anteroinferior glenohumeral ligament and the anteroinferior capsule increased elevation, and releasing the posterior-superior capsule increased IR (38). Further comparative studies are needed according to the optimal extent of a glenohumeral ligament release, including with or without the CHL release.

Our study has several limitations. First, the study design was retrospective. Second, the number of enrolled patients was relatively small. Third, the mean follow-up period of 15.6 months was relatively short. Finally, the MGHL has the greatest variation in its shape and size among all the ligaments of the shoulder joint (3941). The common variations of MGHL include a sublabral foramen, cord-like MGHL, and the Buford complex (40, 41). The incidence rate is reported to range from 8–12% for the sublabral foramen, 1.5–5% for the Buford complex, and 19–23% for the cord-like MGHL. We could not evaluate the variation of the MGHL in this study.

Conclusions

ARCR with preemptive MGHL release could not be an effective method to reduce postoperative stiffness.

Abbreviations

MGHL: middle glenohumeral ligamentrelease

ARCR: arthroscopic rotator cuff repair 

ROM: range of motion

CHL: coracohumeral ligament

RI: rotator interval 

ER: external rotation

IR: internal rotation

MRI: magnetic resonance imaging

JOA score: Japanese Orthopedic Association Shoulder Score

UCLA score: the University of California, Los Angeles Score 

Declarations

Ethics approval and consent to participate

The Institutional Review Board of the Ichinomiya Nishi Hospital approved this study. All methods in this study were performed in accordance with the ethical standards of the Institutional Review Board of the Ichinomiya Nishi Hospital, the 1964 Declaration of Helsinki and its subsequent amendments. Informed consent was obtained from all particilants and their parents.

Consent for publication

Not applicable.

Availability of data and materials

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.

Competing interests

The authors declare that they have no competing interests.

Funding

The authors did not receive any funding or grants in support of this study.

Authors’ contributions

All authors contributed to the study’s conception and design. YK, YH, and YI designed the study, drafted the manuscript, and designed the figures. YK and YH collected the clinical data and performed the analysis. YK and YI aided in interpreting the results, supervised the work, and performed corrections of the first draft. All authors have read and approved the final submitted manuscript.

Acknowledgements

Not applicable

References

  1. Tauro JC. Stiffness and rotator cuff tears: incidence, arthroscopic findings, and treatment results. Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association. 2006 Jun;22(6):581–6.
  2. Brislin KJ, Field LD, Savoie FH 3. rd. Complications after arthroscopic rotator cuff repair.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2007Feb;23(2):124–8.
  3. Chang KV, Hung CY, Han DS, Chen WS, Wang TG, Chien KL. Early Versus Delayed Passive Range of Motion Exercise for Arthroscopic Rotator Cuff Repair: A Meta-analysis of Randomized Controlled Trials.The American journal of sports medicine2015May;43(5):1265–73.
  4. Chan K, MacDermid JC, Hoppe DJ, Ayeni OR, Bhandari M, Foote CJ, Athwal GS. Delayed versus early motion after arthroscopic rotator cuff repair: a meta-analysis.Journal of shoulder and elbow surgery2014Nov;23(11):1631–9.
  5. Cho NS, Rhee YG. Functional outcome of arthroscopic repair with concomitant manipulation in rotator cuff tears with stiff shoulder.The American journal of sports medicine2008Jul;36(7):1323–9.
  6. Denard PJ, Ladermann A, Burkhart SS. Prevention and management of stiffness after arthroscopic rotator cuff repair: systematic review and implications for rotator cuff healing.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2011Jun;27(6):842–8.
  7. Hsu SL, Ko JY, Chen SH, Wu RW, Chou WY, Wang CJ. Surgical results in rotator cuff tears with shoulder stiffness.Journal of the Formosan Medical Association = Taiwan yi zhi2007 Jun;106(6):452–61.
  8. Kim JH, Ha DH, Kim SM, Kim KW, Han SY, Kim YS. Does arthroscopic preemptive extensive rotator interval release reduce postoperative stiffness after arthroscopic rotator cuff repair?: a prospective randomized clinical trial.Journal of shoulder and elbow surgery2019Sep;28(9):1639–46.
  9. Park JH, Yang SH, Rhee SM, Oh JH. The effect of concomitant coracohumeral ligament release in arthroscopic rotator cuff repair to prevent postoperative stiffness: a retrospective comparative study. Knee surgery, sports traumatology, arthroscopy: official journal of the ESSKA2019 Dec;27(12):3881–9.
  10. Mengiardi B, Pfirrmann CW, Gerber C, Hodler J, Zanetti M. Frozen shoulder: MR arthrographic findings.Radiology2004Nov;233(2):486–92.
  11. Neviaser RJ, Neviaser TJ. The frozen shoulder. Diagnosis and management.Clinical orthopaedics and related research1987 Oct(223):59–64.
  12. Parker RD, Froimson AI, Winsberg DD, Arsham NZ. Frozen shoulder. Part II: Treatment by manipulation under anesthesia.Orthopedics1989Jul;12(7):989–90.
  13. Holloway GB, Schenk T, Williams GR, Ramsey ML, Iannotti JP. Arthroscopic capsular release for the treatment of refractory postoperative or post-fracture shoulder stiffness.The Journal of bone and joint surgery American volume2001Nov;83(11):1682–7.
  14. Manaka T, Ito Y, Matsumoto I, Takaoka K, Nakamura H. Functional recovery period after arthroscopic rotator cuff repair: is it predictable before surgery?Clinical orthopaedics and related research2011Jun;469(6):1660–6.
  15. Cofield RH, Parvizi J, Hoffmeyer PJ, Lanzer WL, Ilstrup DM, Rowland CM. Surgical repair of chronic rotator cuff tears. A prospective long-term study.The Journal of bone and joint surgery American volume2001Jan;83(1):71–7.
  16. Giuseffi S, Field LD, Giel TV 3rd, Brislin BT, Savoie FH. 3rd. Arthroscopic Rotator Cuff Repair With Concomitant Capsular Release.Arthroscopy techniques2016Aug;5(4):e833-e7.
  17. Kajita Y, Iwahori Y, Harada Y, Takahashi R, Sagami R, Deie M. Clinical outcome and repair integrity after arthroscopic full-thickness rotator cuff repair: Triple-row versus suture-bridge techniques.Journal of orthopaedic science: official journal of the Japanese Orthopaedic Association2022 Jun7.
  18. Sugaya H, Maeda K, Matsuki K, Moriishi J. Repair integrity and functional outcome after arthroscopic double-row rotator cuff repair. A prospective outcome study.The Journal of bone and joint surgery American volume2007May;89(5):953–60.
  19. Huberty DP, Schoolfield JD, Brady PC, Vadala AP, Arrigoni P, Burkhart SS. Incidence and treatment of postoperative stiffness following arthroscopic rotator cuff repair.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2009Aug;25(8):880–90.
  20. Itoi E, Arce G, Bain GI, Diercks RL, Guttmann D, Imhoff AB, Mazzocca AD, Sugaya H, Yoo YS. Shoulder Stiffness: Current Concepts and Concerns.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2016Jul;32(7):1402–14.
  21. Seo SS, Choi JS, An KC, Kim JH, Kim SB. The factors affecting stiffness occurring with rotator cuff tear.Journal of shoulder and elbow surgery2012Mar;21(3):304–9.
  22. Warner JJ, Greis PE. The treatment of stiffness of the shoulder after repair of the rotator cuff. Instr Course Lect. 1998;47:67–75.
  23. Cucchi D, Marmotti A, De Giorgi S, Costa A, D'Apolito R, Conca M, Russo A, Saccomanno MF, de Girolamo L, Committee SR. Risk Factors for Shoulder Stiffness: Current Concepts.Joints2017Dec;5(4):217–23.
  24. Ansok CB, Muh SJ. Optimal management of glenohumeral osteoarthritis. Orthop Res reviews. 2018;10:9–18.
  25. Eraghi AS. Acromioplasty in the surgical operations of partial-thickness rotator cuff tears: A comprehensive review.Journal of family medicine and primary care2020Feb;9(2):520–5.
  26. Guity MR, Eraghi AS. Open Rotator Cuff Tear Repair Using Deltopectoral Approach.Medical archives2015Oct;69(5):298–301.
  27. Clark JM, Harryman DT 2. nd. Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy.The Journal of bone and joint surgery American volume1992Jun;74(5):713–25.
  28. Arai R, Nimura A, Yamaguchi K, Yoshimura H, Sugaya H, Saji T, Matsuda S, Akita K. The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle.Journal of shoulder and elbow surgery2014Oct;23(10):1575–81.
  29. Ozaki J, Nakagawa Y, Sakurai G, Tamai S. Recalcitrant chronic adhesive capsulitis of the shoulder. Role of contracture of the coracohumeral ligament and rotator interval in pathogenesis and treatment.The Journal of bone and joint surgery American volume1989Dec;71(10):1511–5.
  30. Neer CS 2nd, Satterlee CC, Dalsey RM, Flatow EL. The anatomy and potential effects of contracture of the coracohumeral ligament.Clinical orthopaedics and related research1992 Jul(280):182–5.
  31. Harryman DT 2nd, Sidles JA, Harris SL, Matsen FA 3. rd. The role of the rotator interval capsule in passive motion and stability of the shoulder.The Journal of bone and joint surgery American volume1992Jan;74(1):53–66.
  32. Tsai MJ, Ho WP, Chen CH, Leu TH, Chuang TY. Arthroscopic extended rotator interval release for treating refractory adhesive capsulitis.Journal of orthopaedic surgery2017Jan;25(1):2309499017692717.
  33. Plausinis D, Bravman JT, Heywood C, Kummer FJ, Kwon YW, Jazrawi LM. Arthroscopic rotator interval closure: effect of sutures on glenohumeral motion and anterior-posterior translation.The American journal of sports medicine2006Oct;34(10):1656–61.
  34. Mologne TS, Zhao K, Hongo M, Romeo AA, An KN, Provencher MT. The addition of rotator interval closure after arthroscopic repair of either anterior or posterior shoulder instability: effect on glenohumeral translation and range of motion.The American journal of sports medicine2008Jun;36(6):1123–31.
  35. Oh JH, Kim SH, Lee HK, Jo KH, Bin SW, Gong HS. Moderate preoperative shoulder stiffness does not alter the clinical outcome of rotator cuff repair with arthroscopic release and manipulation.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2008Sep;24(9):983–91.
  36. Cvetanovich GL, Leroux TS, Bernardoni ED, Hamamoto JT, Saltzman BM, Verma NN, Romeo AA. Clinical Outcomes of Arthroscopic 360 degrees Capsular Release for Idiopathic Adhesive Capsulitis in the Lateral Decubitus Position.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2018Mar;34(3):764–70.
  37. Hagiwara Y, Kanazawa K, Ando A, Sekiguchi T, Yabe Y, Takahashi M, Koide M, Takahashi N, Sugaya H. Clinical outcomes of arthroscopic pan-capsular release with or without entire coracohumeral ligament release for patients with frozen shoulder.JSES international2020Dec;4(4):826–32.
  38. Bowen MK, Warren RF. Ligamentous control of shoulder stability based on selective cutting and static translation experiments.Clinics in sports medicine1991Oct;10(4):757–82.
  39. Collotte P, Nove-Josserand L. Arthroscopic anatomy of the middle glenohumeral ligament.Surgical and radiologic anatomy: SRA2018Dec;40(12):1363–70.
  40. Ilahi OA, Labbe MR, Cosculluela P. Variants of the anterosuperior glenoid labrum and associated pathology.Arthroscopy: the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association2002Oct;18(8):882–6.
  41. Lee BI, Kim YB, Won SH, Hwang SC, Choi SW, Nho JH, Chun DI. Isolated tear of the cord-like middle glenohumeral ligament in Buford complex: A case report.Medicine2017Nov;96(45):e8604.