title: Deltoid muscle volume affects clinical outcome of reverse total shoulder arthroplasty in patients with cuff tear arthropathy or irreparable cuff tears.
abstract: We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA.
authors.affiliation: Department of Orthopaedic Surgery, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Jong Pil
authors.initials: JP
authors.lastname: Yoon
authors.affiliation: Institute of Advanced Convergence Technology, Kyungpook National University, Daegu, Korea.
authors.forename: Anna
authors.initials: A
authors.lastname: Seo
authors.affiliation: Institute of Advanced Convergence Technology, Kyungpook National University, Daegu, Korea.
authors.forename: Jeong Jun
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Chang-Hwa
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Orthopaedic Surgery, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Seung-Hun
authors.initials: SH
authors.lastname: Baek
authors.affiliation: Department of Orthopaedic Surgery, Kyungpook National University College of Medicine, Daegu, Korea.
authors.forename: Shin Yoon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Eun Taek
authors.initials: ET
authors.lastname: Jeong
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Kyung-Soo
authors.initials: KS
authors.lastname: Oh
authors.affiliation: Department of Orthopaedic Surgery, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Seok Won
authors.identifier: http://orcid.org/0000-0002-8221-9289
authors.initials: SW
authors.lastname: Chung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072228:Arthroplasty, Replacement, Shoulder; D057645:Deltoid Muscle / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D009929:Organ Size; D016059:Range of Motion, Articular; D020127:Recovery of Function; D000070656:Rotator Cuff Tear Arthropathy / Q000000981:diagnostic imaging / Q000601:surgery*; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome