[Orthopaedic robot assisted closed reduction and cannulated screw internal fixation for the treatment of femoral neck fractures].

OBJECTIVE: To investigate the preliminary clinical effect of closed reduction and cannulated nail internal fixation for femoral neck fracture assisted by robot navigation and positioning system. METHODS: From July 2019 to January 2020, 16 cases of femoral neck fracture （navigation group） were treated with closed reduction and internal fixation guided by robot system, including 7 males and 9 females, aged 25 to 72 years old with an average of （53.61±5.45） years old；Garden classification of fracture：3 cases of typeⅠ, 3 cases of typeⅡ, 8 cases of type Ⅲ, 2 cases of type Ⅳ. Non navigation group （control group）：20 cases of femoral neck fracture were treated with closed reduction and hollow nail internal fixation, 8 males and 12 females, aged 46 to 70 years old with an average of （55.23±4.64） years old；Garden typeⅠin 2 cases, typeⅡin 4 cases, type Ⅲ in 11 cases, type Ⅳ in 3 cases. The operation time, fluoroscopy times, guide needle drilling times, screw adjustment times, intraoperative bleeding volume and other indicators of two groups were evaluated. RESULTS: Both groups were followed up for 12 to 18 months with an average of （15.6±2.8） months. The fractures of both groups were healed without delayed union and nonunion. There was no significant difference in healing time between two groups（P=0.782）. There was no significant difference in Harris scores between two groups at the last follow-up（P=0.813）. There was no significant difference in operation time between two groups（P>0.05）. There were significant differences between two groups in fluoroscopy times, guide needle drilling times, hollow screw replacement times, and intraoperative bleeding volume（P<0.05）. CONCLUSION: Closed reduction and hollow screw internal fixation assisted by robot navigation system for femoral neck fracture has the advantages of minimally invasive operation, precise screw placement, and reduction of X-ray radiation damage during operation.

[CT measurement and clinical application of double-row suture anchor reconstruction for the treatment of Tossy type III acromioclavicular joint dislocation].

OBJECTIVE: To study feasibility and reliability of reconstruction of the acromioclavicular ligament with double-row suture anchor for the treatment of acromioclavicular joint dislocation through coracoid coronal CT measurement, and to provide a new operation method for treating acromioclavicular joint dislocation. METHODS: Total 60 healthy people received CT examination of shoulder joint, including 30 males and 30 females, ranging in age from 18 to 50 years old. The coronal width, thickness and 20 degree camber angle in the medial part of the toot of coronal were measured using CT scan. The results were applied to clinical treatment for 12 patients with acromioclavicular joint dislocation of Tossy III type. RESULTS: The width in the medial part of the root of the coracoid was(17.65±1.82) mm(left side) and (17.67±1.80) mm(right side) in males; (16.55±1.78) mm(left side) and (16.52±1.74) mm (right side) in females. The vertical thickness of the roots of the coracoid: (13.11±2.11) mm(left side) and (13.16±2.09) mm(right side) in males;(12.79±2.21) mm(left side) and (12.76±2.19) mm (right side) in females. The thickness of 20 degrees camber angle of the coracoid roots: (16.32±1.74) mm (left side) and (16.30±1.69) mm(right side) in males; (15.68±1.44) mm(left side) and (15.67±1.43) mm(right side) in females. Total 12 patients were treated with anchor nail with extraversion 20 degrees. The postoperative X-ray films showed bone anchors were located in the coracoid process, no bone splitting. CONCLUSIONS: Double-row suture anchor of 5 mm diameter nails can be placed into coracoid with extraversion 20 degrees, which is safety.