PMID- 38294257 OWN - NLM STAT- MEDLINE DCOM- 20240304 LR - 20240304 IS - 1552-3365 (Electronic) IS - 0363-5465 (Print) IS - 0363-5465 (Linking) VI - 52 IP - 3 DP - 2024 Mar TI - Anterior Latissimus Dorsi Transfer for Irreparable Subscapularis Tears Improves Shoulder Kinematics in a Dynamic Biomechanical Cadaveric Shoulder Model. PG - 624-630 LID - 10.1177/03635465231223514 [doi] AB - BACKGROUND: In young patients with irreparable subscapularis deficiency (SSC-D) and absence of severe osteoarthritis, anterior latissimus dorsi transfer (aLDT) has been proposed as a treatment option to restore the anteroposterior muscular force couple to regain sufficient shoulder function. However, evidence regarding the biomechanical effect of an aLDT on glenohumeral kinematics remains sparse. PURPOSE/HYPOTHESIS: The purpose of this study was to investigate the effects of an aLDT on range of glenohumeral abduction motion, superior migration of the humeral head (SM), and cumulative deltoid force (cDF) in a simulated SSC-D model using a dynamic shoulder model. It was hypothesized that an aLDT would restore native shoulder kinematics by reestablishing the insufficient anteroposterior force couple. STUDY DESIGN: Controlled laboratory study. METHODS: Eight fresh-frozen cadaveric shoulders were tested using a validated shoulder simulator. Glenohumeral abduction angle (gAA), SM, and cDF were compared across 3 conditions: (1) native, (2) SSC-D, and (3) aLDT. gAA and SM were measured using 3-dimensional motion tracking, while cDF was recorded in real time during dynamic abduction motion by load cells connected to actuators. RESULTS: The SSC-D significantly decreased gAA (Delta-9.8 degrees ; 95% CI, -14.1 degrees to -5.5 degrees ; P < .001) and showed a significant increase in SM (Delta2.0 mm; 95% CI, 0.9 to 3.1 mm; P = .003), while cDF was similar (Delta7.8 N; 95% CI, -9.2 to 24.7 N; P = .586) when compared with the native state. Performing an aLDT resulted in a significantly increased gAA (Delta3.8 degrees ; 95% CI, 1.8 degrees to 5.7 degrees ; P < .001), while cDF (Delta-36.1 N; 95% CI, -48.7 to -23.7 N; P < .001) was significantly reduced compared with the SSC-D. For the aLDT, no anterior subluxation was observed. However, the aLDT was not able to restore native gAA (Delta-6.1 degrees ; 95% CI, -8.9 degrees to -3.2 degrees ; P < .001). CONCLUSION: In this cadaveric study, performing an aLDT for an irreparable subscapularis insufficiency restored the anteroposterior force couple and prevented superior and anterior humeral head migration, thus improving glenohumeral kinematics. Furthermore, compensatory deltoid forces were reduced by performing an aLDT. CLINICAL RELEVANCE: Given the favorable effect of the aLDT on shoulder kinematics in this dynamic shoulder model, performing an aLDT may be considered as a treatment option in patients with irreparable SSC-D. FAU - Berthold, Daniel P AU - Berthold DP AUID- ORCID: 0000-0001-6630-6406 AD - Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany. AD - Department of Sports Orthopaedics, Technical University of Munich, Munich, Germany. FAU - Rupp, Marco-Christopher AU - Rupp MC AD - Department of Sports Orthopaedics, Technical University of Munich, Munich, Germany. FAU - Obopilwe, Elifho AU - Obopilwe E AD - Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, USA. FAU - Siebenlist, Sebastian AU - Siebenlist S AD - Department of Sports Orthopaedics, Technical University of Munich, Munich, Germany. FAU - Elhassan, Bassem T AU - Elhassan BT AD - Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA. FAU - Mazzocca, Augustus D AU - Mazzocca AD AD - Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA. FAU - Muench, Lukas N AU - Muench LN AD - Department of Sports Orthopaedics, Technical University of Munich, Munich, Germany. AD - Department of Trauma Surgery, Armed Klinikum Munchen Sud, Munich, Germany. LA - eng PT - Journal Article DEP - 20240131 PL - United States TA - Am J Sports Med JT - The American journal of sports medicine JID - 7609541 SB - IM MH - Humans MH - Shoulder/surgery MH - Rotator Cuff/surgery MH - Biomechanical Phenomena MH - *Superficial Back Muscles/surgery MH - *Bursitis MH - Cadaver PMC - PMC10905977 OTO - NOTNLM OT - irreparable subscapularis tear OT - latissimus dorsi transfer OT - muscular force couple OT - shoulder kinematics OT - subscapularis deficiency OT - tendon transfer COIS- One or more of the authors has declared the following potential conflict of interest or source of funding: S.S. has received consulting fees from Arthrex GmbH, Medi GmbH & Co, and KLS Martin Group. A.D.M. has received consulting fees from Arthrex and Astellas Pharma, speaking fees from Kairos Surgical, and honoraria from Arthrosurface. The University of Connecticut Health Center/UConn Musculoskeletal Institute has received direct funding and material support from Arthrex Inc. The company had no influence on study design, data collection, or interpretation of the results or the final manuscript. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto. EDAT- 2024/01/31 12:44 MHDA- 2024/03/04 06:49 PMCR- 2024/03/01 CRDT- 2024/01/31 09:13 PHST- 2024/03/04 06:49 [medline] PHST- 2024/01/31 12:44 [pubmed] PHST- 2024/01/31 09:13 [entrez] PHST- 2024/03/01 00:00 [pmc-release] AID - 10.1177_03635465231223514 [pii] AID - 10.1177/03635465231223514 [doi] PST - ppublish SO - Am J Sports Med. 2024 Mar;52(3):624-630. doi: 10.1177/03635465231223514. Epub 2024 Jan 31.