Fatty Degeneration of Subscapularis Muscle after Total Shoulder Arthroplasty: A CT-scan Analysis from SFI study Group

Arnaud Godeneche; Thierry Joudet; Christophe Charousset; Stephane Audebert; Yves Lefebvre; Johannes Barth; Jerome Garret; David Gallinet; Jacques Guery; SFI; Nicolas Bonnevialle; Hugo Barret

Abstract

Background: Postoperative dysfunction of subscapularis muscle is a well-known cause of failure following anatomic total shoulder arthroplasty surgery (aTSA).Purpose: To evaluate postoperative fatty degeneration of subscapularis muscle following anatomic shoulder replacement.Methods: In a prospective multicenter study, we included patients who underwent aTSA, with preoperative subscapularis fatty degeneration grade 0 (Goutallier classification system) and with CT-scan performed at 12 months postoperative. The fatty degeneration and trophicity of the subscapularis muscle were analysed by two senior surgeons. The subscapularis was divided into an upper and lower part on a sagittal view.Results: From an indexed database comprising 120 patients, 100 patients (104 CT scans) were included. Subscapularis tenotomy (n = 77) or peel-off technic (n = 27) was performed. Tendon repair was performed either by trans osseous fixation with looped sutures (n = 89) or with anchors alone (n = 15). After a mean follow-up of 16 ± 4 months, fatty degeneration of the subscapularis muscle increased in all patients. In the upper part of the subscapularis, the mean Goutallier stage was 2 ± 0.3. In the lower part of the subscapularis, the mean Goutallier stage was 1.2 ± 0.3 (p = 0.01). The trans osseous reinsertion technique provided better protection of the subscapularis than anchors in the upper and lower parts of the subscapularis (1.8 ± 0.7 vs 2.67 ± 1, p = 0.04; and 1 ± 0.8 vs 1.8 ± 1.1, p = 0.01, respectively). Inter- and intra-rater reliability was satisfactory for the assessment of fatty degeneration, while inter- and intra-rater reliability was moderate for trophicity.Conclusion: In short-term follow-up after aTSA without preoperative subscapularis muscle injury, fatty infiltration is greater in the upper subscapularis than in the lower subscapularis, regardless of the surgical technique used. Transosseous reinsertion of the subscapularis tendon appears to cause less damage to the subscapularis muscle in anatomic shoulder arthroplasty. A longer clinical and radiological follow-up is necessary to find the best management of the subscapularis in aTSA.What this study adds: a precise assessment of the subscapularis in anatomical prostheses with a division between the upper and lower subscapularis.Potential impacts on research, practice, or policy: use of transosseous reinsertion of the subscapularis rather than anchors; medium- and long-term follow-up of patients and the subscapularis with precise imaging examinationsStudy Design: Case seriesLevel of evidence: Level IVKeywords: osteoarthritis; anatomic total shoulder arthroplasty, CT scan; fatty degeneration; subscapularis; stemless.https://doi.org/10.70885/hmsj.2025.08.001A correction has been applied to this article on 15.01.2026: https://doi.org/10.70885/hmsj.2026.01.003

References

  1. Best MJ, Aziz KT, Wilckens JH, McFarland EG, Srikumaran U. Increasing incidence of primary reverse and anatomic total shoulderarthroplasty in the United States. J Shoulder Elbow Surg. 2021 May;30(5):1159-1166. doi: 10.1016/j.jse.2020.08.010
  2. Jomaa M, Ingoe H, Hollman F, Pareyón R, Whitehouse SL, Du P, Gill DR, Maharaj J, Gupta A, Cutbush K. Stemless Anatomic and Reverse Shoulder Arthroplasty in Patients under 55 years of age with Primary Glenohumeral Osteoarthritis: An analysis of the Australian Orthopaedic Association National Joint Replacement Registry at five years. J Shoulder Elbow Surg. 2024 Sep 12:S1058-2746(24)00624-4. doi: 10.1016/j.jse.2024.07.032
  3. Khoriati AA, McBride AP, Ross M, Duke P, Hoy G, Page R, Holder C, Taylor F.J Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2023 Oct;32(10):2105-2114. doi: 10.1016/j.jse.2023.03.024
  4. Shields E, Ho A, Wiater JM. Management of the subscapularis tendon during total shoulder arthroplasty. J Shoulder Elbow Surg. 2017 Apr;26(4):723-731. doi: 10.1016/j.jse.2016.11.006
  5. Lapner PL, Sabri E, Rakhra K, Bell K, Athwal GS. Comparison of lesser tuberosity osteotomy to subscapularis peel in shoulder arthroplasty: a randomized controlled trial. J Bone Joint Surg Am. 2012 Dec 19;94(24):2239-46. doi: 10.2106/JBJS.K.01365.
  6. Lapner PL, Sabri E, Rakhra K, Bell K, Athwal GS. Healing rates and subscapularis fatty infiltration after lesser tuberosity osteotomy versus subscapularis peel for exposure during shoulder arthroplasty. J Shoulder Elbow Surg. 2013 Mar;22(3):396-402. doi: 10.1016/j.jse.2012.05.031
  7. Gerber C, Yian EH, Pfirrmann CA, Zumstein MA, Werner CM. Subscapularis muscle function and structure after total shoulder replacement with lesser tuberosity osteotomy and repair. J Bone Joint Surg Am. 2005 Aug;87(8):1739-45. doi: 10.2106/JBJS.D.02788.
  8. Collin P, Lädermann A, Le Bourg M, Walch G. Subscapularis minor--an analogue of the Teres minor? Orthop Traumatol Surg Res. 2013 Jun;99(4 Suppl):S255-8. doi: 10.1016/j.otsr.2013.03.003
  9. Wickham J, Pizzari T, Balster S, Ganderton C, Watson L. The variable roles of the upper and lower subscapularis during shoulder motion. Clin Biomech (Bristol). 2014 Sep;29(8):885-91. doi: 10.1016/j.clinbiomech.2014.07.003
  10. Rathi S, Taylor NF, Green RA. The upper and lower segments of subscapularis muscle have different roles in glenohumeral joint functioning. J Biomech. 2017 Oct 3;63:92-97. doi: 10.1016/j.jbiomech.2017.08.007.
  11. Conboy VB, Morris RW, Kiss J, Carr AJ. An evaluation of the Constant-Murley shoulder assessment. J Bone Joint Surg Br 1996;78(2): 229-32 DOI:10.1302/0301-620X.78B2.0780229
  12. Gilbart MK, Gerber C. Comparison of the subjective shoulder value and the Constant score. J Shoulder Elbow Surg 2007;16(6):717-21 DOI:10.1016/j.jse.2007.02.123
  13. Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res. juill 1994;(304):78 - 83
  14. Miller BS, Joseph TA, Noonan TJ, Horan MP, Hawkins RJ. Rupture of the subscapularis tendon after shoulder arthroplasty: diagnosis, treatment, and outcome. J Shoulder Elbow Surg. 2005 Sep-Oct;14(5):492-6. doi: 10.1016/j.jse.2005.02.013
  15. Scheibel M, Habermeyer P. Subscapularis dysfunction following anterior surgical approaches to the shoulder.J Shoulder Elbow Surg. 2008 Jul-Aug;17(4):671-83. doi: 10.1016/j.jse.2007.11.005
  16. Baumgarten KM, Osborn R, Schweinle WE Jr, Zens MJ. The influence of anatomic total shoulder arthroplasty using a subscapularis tenotomy on shoulder strength. J Shoulder Elbow Surg. 2018 Jan;27(1):82-89. doi: 10.1016/j.jse.2017.06.043
  17. Werner BC, Griffin JW, Thompson T, Lendhey M, Higgins LD, Denard PJ. Biomechanical evaluation of 2 techniques of repair after subscapularis peel for stemless shoulder arthroplasty. J Shoulder Elbow Surg. 2021 Oct;30(10):2240-2246. doi: 10.1016/j.jse.2021.01.037
  18. Savoie FH 3rd, Charles R, Casselton J, O'Brien MJ, Hurt JA 3rd. The subscapularis-sparing approach in humeral head replacement.J Shoulder Elbow Surg. 2015 Apr;24(4):606-12. doi: 10.1016/j.jse.2014.07.020
  19. Simovitch RW, Nayak A, Scalise J, Boudreaux R, Olmscheid N, Worhacz K, Jacofsky M, Vanasse T, Roche C. Biomechanical characteristics of subscapularis-sparing approach for anatomic total shoulder arthroplasty. J Shoulder Elbow Surg. 2018 Jan;27(1):133-140. doi: 10.1016/j.jse.2017.08.022
  20. Ding DY, Mahure SA, Akuoko JA, Zuckerman JD, Kwon YW. Total shoulder arthroplasty using a subscapularis-sparing approach: a radiographic analysis. J Shoulder Elbow Surg. 2015 Jun;24(6):831-7. doi: 10.1016/j.jse.2015.03.009.
  21. De Wilde LF, De Coninck T, De Neve F, Berghs BM. Subscapularis release in shoulder replacement determines structural muscular changes.Clin Orthop Relat Res. 2012 Aug;470(8):2193-201. doi: 10.1007/s11999-012-2291-x
  22. Shi LL, Jiang JJ, Ek ET, Higgins LD. Failure of the lesser tuberosity osteotomy after total shoulder arthroplasty. J Shoulder Elbow Surg. 2015 Feb;24(2):203-9. doi: 10.1016/j.jse.2014.05.006
  23. Levine WN, Munoz J, Hsu S, Byram IR, Bigliani LU, Ahmad CS, Kongmalai P, Shillingford JN. Subscapularis tenotomy versus lesser tuberosity osteotomy during total shoulder arthroplasty for primary osteoarthritis: a prospective, randomized controlled trial. J Shoulder Elbow Surg. 2019 Mar;28(3):407-414. doi: 10.1016/j.jse.2018.11.057
  24. Lapner P, Pollock JW, Zhang T, Ruggiero S, Momoli F, Sheikh A, Athwal GS. A randomized controlled trial comparing subscapularis tenotomy with peel in anatomic shoulder arthroplasty. J Shoulder Elbow Surg. 2020 Feb;29(2):225-234. doi: 10.1016/j.jse.2019.09.028
  25. Lapner PL, Wood KS, Zhang T, Athwal GS. The return of subscapularis strength after shoulder arthroplasty. J Shoulder Elbow Surg. 2015 Feb;24(2):223-8. doi: 10.1016/j.jse.2014.06.042
  26. Werner BC, McClish SJ, Mealey NC, Wijdicks C, Thompson T, Higgins LD. A biomechanical comparison of subscapularis tenotomy repair techniques for stemless shoulder arthroplasty. J Shoulder Elbow Surg. 2022 Apr;31(4):711-717. doi: 10.1016/j.jse.2021.10.017
  27. Werner BC, Griffin JW, Thompson T, Lendhey M, Higgins LD, Denard PJ. Biomechanical evaluation of 2 techniques of repair after subscapularis peel for stemless shoulder arthroplasty. J Shoulder Elbow Surg. 2021 Oct;30(10):2240-2246. doi: 10.1016/j.jse.2021.01.037
  28. Aibinder WR, Bicknell RT, Bartsch S, Scheibel M, Athwal GS. Subscapularis management in stemless total shoulder arthroplasty: tenotomy versus peel versus lesser tuberosity osteotomy. J Shoulder Elbow Surg. 2019 Oct;28(10):1942-1947. doi: 10.1016/j.jse.2019.02.022
  29. Melis B, DeFranco MJ, Lädermann A, Barthelemy R, Walch G. The teres minor muscle in rotator cuff tendon tears. Skeletal Radiol. 2011 Oct;40(10):1335-44. doi: 10.1007/s00256-011-1178-3
  30. Yoon TH, Kim SJ, Choi YR, Oh JH, Chun YM. Comparison of the Goutallier Classification of Fatty Infiltration for the Subscapularis With a Novel Modified Classification. Orthop J Sports Med. 2023 Aug 10;11(8):23259671231174428. doi: 10.1177/23259671231174428

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