[Objective]To investigate the late results of pedicle screw system and cage fixation for lumbar broken isthmus spondylolisthesis.[Method]Totally 86 patients with broken isthmus spondylolisthesis were collected and analyzed from October 1996 to October 2002,they were all reduced and fixed with pedicle screw system and cage.Group 1,62 patients were put one cage in the interbody at an angle of 45 degree from posterior to anterior,while Group 2,24 patients were put two cages in the interbody vertically from posterior to anterior.The height of interbody and the most proximal interbody' s height were measured,the rate was calculated.These rate were acquired preoperatively,2 weeks postoperatively and follow-up period respectively.[Result]The follow-up period was 24~96 months,averaged 35 months.The excellent and good rates were 80.23 per cent,according to Nakai standard.Ninteen patients with one degree spondylolisthesis were reduced anatomically after surgery.Fifty-one patients with two degree spondylolisthesis were reduced anatomically except 5 patients with one degree spondylolisthesis left.Sixteen patients with three degree spondylolisthesis were reduced anatomically except 4 patients with one degree spondylolisthesis left.There were loss of spondylolisthesis reduction at follow-up period comparing with 2 weeks postoperatively in two groups.However there was no statistical significance between the two groups.[Conclusion]Lumbar spondylolisthesis should be treated with pedicle screw system and cage,which may decrease the complications such as broken screw and spondylolisthesis recurrency postoperatively.One piece of cage is enough to make interbody stable.It is also an ideal procedure for lumbar spondylolisthesis.

[Objective] To evaluate the efficiency of Halovest external immobilization on the treatment of traumatic cervical fracture or dislocation.[Method]From February 1997 to July 2005,129 patients with cervical fracture or dislocation were treated in our hospital;all the patients were divided into two groups randomly.First group: 70 patients were treated with Halo-vest traction,among them 31 patients were treated with Halo vest combined jacket orthosis;others were treated with Halo vests and surgery(anterior route approach 18 cases,posterior route approach 17 cases,4 patients operated by anterior and posterior approach).The second group: 59 patients were treated with skull traction.Among them 13 patients were treated with skull traction and orthosis,others were treated with skull traction and surgery(anterior route approach 22 cases,posterior route approach 20 cases,4 patients operated by anterior and posterior approach).[Result]All the patients were followed 6~48 months(average 12 months).There was no statistical significance in two groups with reduction of upper cervical spine fracture and dislocation.However on the reduction of lower cervical injury groups,the prognosis with Halo-vest is significantly better than the other group.And the time for bed rest was much less than the skull traction.All the patients' spinal cord function improved obviously after treatment.[Conclusion]Halo-vest external fixation is an easy and effective way to treat cervical injuries.It can improve the reduction of the cervical injuries and it's capability of reduction and maintenance are much better than skull traction.