title: Association of lateral humeral offset with functional outcome and geometric restoration in stemless total shoulder arthroplasty.
abstract: BACKGROUND
  Restoration of shoulder geometry is desirable in total shoulder arthroplasty (TSA) and thought to influence the postoperative clinical outcome. We aimed to study the association of postoperative lateral humeral offset (LHO) changes and clinical outcome, as well as to investigate the ability of stemless anatomic TSA to restore shoulder geometry.
  
  
  METHODS
  In patients with primary shoulder osteoarthritis who underwent stemless anatomic TSA, the preoperative and postoperative clinical outcome was measured. Shoulder geometry was measured on preoperative computed tomography for the osteoarthritic shoulder and contralateral healthy shoulder and on postoperative computed tomography for the operated shoulder.
  
  
  RESULTS
  Forty-four patients with a minimum follow-up of 12 months (range, 12-50 months) were available for the study. Postoperatively, the clinical outcome measures improved. The postoperative difference in LHO between the operated shoulder and contralateral healthy shoulder was 1.3 ± 4.6 mm and was correlated with scores on the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire at 3 months (Pearson correlation = 0.36, P = .01) and visual analog scale for pain at rest (Pearson correlation = 0.30, P = .03) and with exertion (Pearson correlation = 0.34, P = .01) at 3 months. Lengthening of LHO was associated with worsening shoulder function at 3 months but not at 12 months. The postoperative shoulder geometric parameters were restored postoperatively to acceptable ranges.
  
  
  CONCLUSIONS
  The stemless anatomic TSA could restore shoulder geometry in an acceptable manner. At 3 months but not at 12 months, increased LHO had a negative effect on shoulder function and resulted in more shoulder pain at rest and with exertion but did not affect quality of life, health status, or range of motion.
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopaedics-Sundsvall), Umeå University, Umeå, Sweden. Electronic address: baqir_kareem@yahoo.com.
authors.forename: Bakir
authors.initials: B
authors.lastname: Kadum
authors.affiliation: Department of Hand Surgery, Umeå University, Umeå, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Wahlström
authors.affiliation: Department of Orthopaedics, Elisabethsjukhuset, Uppsala, Sweden.
authors.forename: Shwan
authors.initials: S
authors.lastname: Khoschnau
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopaedics-Sundsvall), Umeå University, Umeå, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Sjödén
authors.affiliation: Department of Surgical and Perioperative Sciences (Orthopaedics-Sundsvall), Umeå University, Umeå, Sweden.
authors.forename: Arkan
authors.initials: A
authors.lastname: Sayed-Noor
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072228:Arthroplasty, Replacement, Shoulder; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery; D011446:Prospective Studies; D011474:Prosthesis Design; D012785:Shoulder Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D020069:Shoulder Pain / Q000209:etiology; D000072227:Shoulder Prosthesis; D014057:Tomography, X-Ray Computed; D064232:Visual Analog Scale
keywords: Stemless shoulder prosthesis; TESS shoulder prosthesis; lateral humeral offset; shoulder anatomy restoration; shoulder offset; total shoulder arthroplasty