Strength testing after third-degree acromioclavicular dislocations.

Twenty male patients with a grade III acromioclavicular joint dislocation were evaluated more than 2 years after their injury; the average followup was 4.5 years. Strength testing was performed with a Cybex II dynamometer in three planes evaluating flexion, extension, internal rotation, external rotation, abduction, and adduction at 60 and 120 deg/sec. Subjective complaints were minor and neither daily activities nor athletic participation were impaired. Objectively, only one patient had tenderness over the acromioclavicular joint. All patients had full motion and negative impingement signs. Strength testing with the Cybex II dynamometer showed no significant difference (P less than 0.05) between the injured and uninjured shoulder for strength in internal rotation, external rotation, abduction, adduction, extension, or flexion at speeds of 60 and 120 deg/sec. This study shows that the strength of the shoulder is not significantly affected by conservative treatment of grade III acromioclavicular dislocations. Conservative treatment results in minimal or no functional deficit. The authors recommend that grade III acromioclavicular dislocations be treated nonoperatively.