OBJECTIVETo explore causes of shoulder pain and propose prevention measures in treating acromioclavicular joint dislocation.

METHODSFrom January 2005 to January 2013, 86 patients with acromioclavicular joint dislocation (Tossy III) were treated with hook plate fixation, and were divided into two groups. Bsaed on recovery of shoulder function mostly, the patients who suffered from rest pain, motion pain were named as shoulder pain group, while the patients without pain were named as painless group. In shoulder pain group, there were 21 cases including 15 males and and 6 females ranging the age from 22 to 62 years old with an average of (40.6±11.2) years old. There were 8 cases were on the left side and 13 cases were on the right side. In painless group, there were 65 cases including 36 males and and 29 females ranging the age from 19 to 65 years old with an average of (40.0±11.3) years old. There were 33 cases were on the left side and 32 cases were on the right side. The time from injury to operation ranged from 3 h to 8 d with an average of 34.6 h. Shoulder function of all patients were normal before injuried. Postoperative pain, activity of daily living (ADL), range of motion, deltoid muscle strength were compared. Anteflexion,rear protraction, abduction and upthrow of shoulder joint were also compared. Postoperative complications between two groups were observed and compared.

RESULTSAll patients were followed up from 12 to 48 months with an average of 18.5 months. Constant-Murley score were used to evaluate clinical efficacy at the least following up, and 13 cases got an excellent results, 5 moderate, 2 good and 1 poor in shoulder pain group ; while 61 cases were obtained excellent results, 3 moderate and 1 good in painless group. There were significantly differences between two groups in Constant-Murley score and activity of shoulder joint (P<0.05). In shoulder pain group, 3 cases were disconnected, 1 case occurred stress fracture, 9 cases were subacromial impingement syndrome, 5 cases occurred subluxation, 1 case occurred plate breakage and 11 cases were acromioclavicular arthritis.

CONCLUSIONChosing individual clavicular hook plate, fulfilling anatomic reset, paying attention to the repair of articular capsule ligament, and reducing hook and bone antagonism between stress is the key point of preventing and decreasing postoperative shoulder pain.