Surgical treatment for atlas fractures combined with noncontiguous lower cervical fracture-dislocation

English Keywords:Atlas  Fracture  Fracture fixation  Lower cervical spine  Surgical treatment

English Abstract:

  【Abstract】 Objectives: To investigate the clinical features and surgical treatment of atlas fractures combined with noncontiguous lower cervical fracture-dislocation. Methods: A retrospective study was performed on 20 patients with atlas fractures combined with noncontiguous lower cervical fracture-dislocation treated by one-stage operation from October 2005 to May 2011. Five patients suffered from comminuted fracture of the lateral mass associated with bony avulsion of the medial tubercle and transverse ligament (Dickman transverse ligament type II injury), three from bilateral fractures of anterior arch (pre-half Jefferson fractures), five from anterior arc fracture associated with unilateral posterior arc fracture(half-ring Jefferson fracture), two from anterior 3/4 Jefferson fracture(two fracture lines in anterior arch, one fracture line in posterior arch), five from posterior 3/4 Jefferson fracture(one fracture line in anterior arch, two fracture lines in posterior arch). Five cases underwent C1-C2 fusion, seven cases underwent transoral osteosynthesis of the atlas, five cases were performed posterior osteosynthesis of the atlas. For the lower cervical fracture-dislocation, according to Allen classification: five cases had compression-flexion, three cases had compression-extension, eight cases had vertical-compression, two cases had distraction-flexion, two cases had distraction-extension. There were 13 males and 7 females with the mean age of 36 years. All of the 20 cases underwent surgery on both sites simultaneously. Lower cervical fracture-dislocation responsible for neurological deficit was stabilized firstly in 4 cases. For the other 16 cases without neurological involvement, stabilization was performed in atlas alone. Results: All patients were followed up for an average of 26 months(range, 8 to 42 months). According to Frankel grade, there were 1 grade B, 3 grade C, 5 grade D, 11 grade E before operation, and 1 grade C, 3 grade D, 16 grade E after operation respectively. Four cases with neurological defect had neurofunction improved 1 Frankel scale. The operative time ranged from 180 to 240 min with an average of 200min． The intra- operative blood loss ranged from 500 to 1600ml with an average of 760ml． No surgery-related complications were noted. Two cases had venous plexus ruptured due to the use of electrocautery, which ceased by using hemostatic sponge and cotton piece without causing cerebral hemodynamic deficit． No screw looseness or breakage occurred． All cases obtained solid fusion at both atlas fractures and lower cervical fracture-dislocation. Conclusions: Atlas fractures combined with noncontiguous lower cervical fracture-dislocation often lead to the utmost instability of the cervical spine. Surgery at early stage can decrease the rate of complication as well as ensure recovery．