title: Symptomatic residual instability with grade II acromioclavicular injury.
abstract: OBJECTIVE
  Our objective was to evaluate the effectiveness of arthroscopic distal clavicle resection in cases presenting with pain and subtle instability after neglected grade II acromioclavicular (AC) joint dislocation.
  
  
  METHODS
  From February 1998 to May 2006, 17 patients with symptomatic AC instability following chronic grade II AC joint injury were studied. Sixteen patients were male and one female, with a mean age of 48 years. An all-arthroscopic procedure comprising disk removal and distal clavicle resection was performed in all cases. All patients were reviewed clinically, preoperatively and at final follow-up (mean 38 months) using the pain score on a visual analog scale and the Constant score. Strength was measured using an Isobex digital strength analyzer. Patient's personal satisfaction after the procedure was documented as excellent, good or poor. Postoperative AC joint radiographs were routinely obtained in all patients to measure the amount of clavicle resection.
  
  
  RESULTS
  Two patients underwent additional reconstructive surgery for disabling pain and dysfunction even after the arthroscopic resection procedure. The remaining 15 patients were analyzed. The pain scores improved significantly (p = 0.03). The mean pain score was 5.8 (range 5-9) before treatment and 1.6 (range 0-3) at follow-up. The Constant scores had improved significantly at the final follow-up (p = 0.001). The median Constant score increased from 46 (range 36-69) preoperatively to 71 (range 48-84) postoperatively. Strength had improved at the last follow-up. Eleven patients were satisfied and six were not satisfied with this procedure at the final follow-up.
  
  
  CONCLUSIONS
  Arthroscopic distal clavicle resection statistically improved the pain score, Constant score and strength for grade II AC injury with subtle distal clavicle instability. However, six patients (33.5 %) were not satisfied subjectively. This procedure seemed to be a reasonable initial treatment option with lower morbidity.
authors.affiliation: Department of Orthopedic Surgery, St. Paul's Hospital, The Catholic University of Korea, Seoul, Korea.
authors.forename: Hyun-Seok
authors.initials: HS
authors.lastname: Song
authors.forename: Si Young
authors.initials: SY
authors.lastname: Song
authors.forename: Yon-Sik
authors.initials: YS
authors.lastname: Yoo
authors.forename: Yong Beom
authors.initials: YB
authors.lastname: Lee
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Seo
mesh_terms: D000173:Acromioclavicular Joint / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D000328:Adult; D001182:Arthroscopy; D003646:Debridement; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery*; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D010147:Pain Measurement; D011859:Radiography; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016896:Treatment Outcome