title: Prevalence of neurologic lesions after total shoulder arthroplasty.
abstract: BACKGROUND
  Clinically evident neurologic injury of the involved limb after total shoulder arthroplasty is not uncommon, but the subclinical prevalence is unknown. The purposes of this prospective study were to determine the subclinical prevalence of neurologic lesions after reverse shoulder arthroplasty and anatomic shoulder arthroplasty, and to evaluate the correlation of neurologic injury to postoperative lengthening of the arm.
  
  
  METHODS
  All patients undergoing either a reverse or an anatomic shoulder arthroplasty were included during the period studied. This study focused on the clinical, radiographic, and preoperative and postoperative electromyographic evaluation, with measurement of arm lengthening in patients who had reverse shoulder arthroplasty according to a previously validated protocol.
  
  
  RESULTS
  Between November 2007 and February 2009, forty-one patients (forty-two shoulders) underwent reverse shoulder arthroplasty (nineteen shoulders) or anatomic primary shoulder arthroplasty (twenty-three shoulders). The two groups were similar with respect to sex distribution, preoperative neurologic lesions, and Constant score. Electromyography performed at a mean of 3.6 weeks postoperatively in the reverse shoulder arthroplasty group showed subclinical electromyographic changes in nine shoulders, involving mainly the axillary nerve; eight resolved in less than six months. In the anatomic shoulder arthroplasty group, a brachial plexus lesion was evident in one shoulder. The prevalence of acute postoperative nerve injury was significantly more frequent in the reverse shoulder arthroplasty group (p = 0.002), with a 10.9 times higher risk (95% confidence interval, 1.5 to 78.5). Mean lengthening (and standard deviation) of the arm after reverse shoulder arthroplasty was 2.7 ± 1.8 cm (range, 0 to 5.9 cm) compared with the normal, contralateral side.
  
  
  CONCLUSIONS
  The occurrence of peripheral neurologic lesions following reverse shoulder arthroplasty is relatively common, but usually transient. Arm lengthening with a reverse shoulder arthroplasty may be responsible for these nerve injuries.
authors.affiliation: Division of Orthopaedics and Trauma Surgery, Department of Surgery, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 4, CH-1211 Geneva 14, Switzerland. alexandre.laedermann@hcuge.ch
authors.forename: A
authors.initials: A
authors.lastname: Lädermann
authors.forename: A
authors.initials: A
authors.lastname: Lübbeke
authors.forename: B
authors.initials: B
authors.lastname: Mélis
authors.forename: R
authors.initials: R
authors.lastname: Stern
authors.forename: P
authors.initials: P
authors.lastname: Christofilopoulos
authors.forename: G
authors.initials: G
authors.lastname: Bacle
authors.forename: G
authors.initials: G
authors.lastname: Walch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019643:Arthroplasty, Replacement / Q000009:adverse effects* / Q000379:methods; D004576:Electromyography; D005260:Female; D005599:Fractures, Ununited / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000453:epidemiology; D059348:Peripheral Nerve Injuries; D011183:Postoperative Complications / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D011859:Radiography; D000070636:Rotator Cuff Injuries; D012785:Shoulder Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D014947:Wounds and Injuries / Q000453:epidemiology