ObjectiveTo evaluate three commonly used internal fixations for general floating shoulder injury by biomechanical testing, in order to provide biomechanics basis for surgical choices. MethodsThe superior shoulder suspensory complex (SSSC) was anatomized from 7 cases of antisepsis cadaveric specimens including collarbone and scapula. In the man-made damage models, 4 statuses including prefixation, pure acromioclavicular joint fixation, acromioclavicular joint fixation with scapula neck single plate fixation, and acromioclavicular joint fixation with scapula neck double plate fixation were tested to measure the range of motion (ROM) and neutral zone (NZ) of scapula neck under different statuses by spinal motion analysis system, and stabilizing function of different fixations for instable SSSC were compared. ResultsThe biomechanical testing showed that the NZs of acromioclavicular joint fixation with scapula neck double plate fixation were respectively flexion-extension (3.88±1.71)°, lateral-bending (1.89±0.21)°, and axial-torque (3.13±1.37)°, and the ROMs were respectively flexion-extension (12.91±4.82)°, lateral-bending (18.44±4.43)°, and axial-torque (11.27±4.41)°, which decreased more evidently than other fixation groups (P<0.05). ConclusionAcromioclavicular joint fixation with scapula neck double plate fixation is the best treatment for floating shoulder injury, which can restore the stability of the shoulder effectively.
ObjectiveTo investigate the effectiveness of double internal fixations of clavicle and scapula and intraoperative reduction of glenopolar angle in the treatment of floating shoulder injuries.MethodsBetween January 2010 and June 2019, 13 patients with floating shoulder injury were treated with double internal fixation of clavicle and scapula and intraoperative reduction of glenopolar angle. There were 11 males and 2 females with an average age of 48 years (range, 25-65 years). The causes of injury included falling from height in 2 cases, traffic accident injury in 3 cases, heavy object injury in 2 cases, and other injuries in 6 cases. There were 2 cases of Ⅰ-B-3 type, 1 case of Ⅰ-C-2 type, 1 case of Ⅰ-C-3 type, 3 cases of Ⅱ-B-2 type, 1 case of Ⅱ-B-3 type, 1 case of Ⅱ-B-4 type, 2 cases of Ⅱ-C-2 type, 1 case of Ⅱ-C-4 type, and 1 case of Ⅱ-D-3 type according to the classification of floating shoulder injury. All patients had unilateral clavicle fracture with scapular neck fracture, 1-4 superior shoulder suspensory complex (SSSC) injuries. The time from injury to operation was 7-17 days, with an average of 12 days. The glenopolar angle, subacromail space, anteroposterior inclination angle of scapular glenoid, scapular glenoid up and down angle were measured before and after operation; Constant-Murly score and Herscovici score were used to evaluate the recovery of shoulder joint function.ResultsAll incisions healed by first intention, and there was no early postoperative complications such as infection. All 13 cases were followed up 12-48 months, with an average of 25.2 months. Both the clavicle and the scapula had bone union, and the average healing time was 6 months and 4 months respectively. There were no complications such as nonunion, shoulder deformity, plate fracture or failure of internal fixation, acromion impingement syndrome, and frozen shoulder. At last follow-up, the glenopolar angle, subacromail space, anteroposterior inclination angle of scapular glenoid, and scapular glenoid up and down angle were all corrected significantly (P<0.05). The pain, function, activity, muscle strength scores, and total score in Constant-Murly score were significantly improved when compared with preoperative scores (P<0.05). According to the Herscovici scoring standard, the shoulder joint function was evaluated as excellent in 8 cases, good in 3 cases, and fair in 2 cases. The excellent and good rate was 84.6%.ConclusionDouble internal fixation of clavicle and scapula to stabilize SSSC and reduct glenopolar angle during operation is an effective method for treating the floating shoulder injury.