[Polyethylene wear and osteolysis in H/G cementless total hip arthroplasty].

OBJECTIVES: To measure the linear polyethylene wear with use of a computer-assisted two-dimensional method, and to evaluate the relationship between wear and long-term clinic-radiological findings. METHODS: Between December 1991 and December 1995, the senior author performed 40 primary total hip arthroplasties with use of H/G porous-coated acetabular component. Radiographs of 40 H/G cementless total hip arthroplasties were examined for osteolysis, radiolucent line, cup migration and so on. To measure the linear polyethylene wear, migration in the femoral head center relative to the cup shell center was calculated on digitized consecutive radiographs with special computer software program. RESULTS: The minimum follow-up was 10 years. Total linear wear was 2-8 mm, the mean rate of linear polyethylene wear was (0.32+/-0.31) mm/year. Twelve acetabular components (30%) were revised at an average follow-up point of 12 years. Three types of polyethylene liner failure were identified: wear-through of the polyethylene liner with resultant metallosis (5 hips), excessive wear necessitating revision (5 hips), and polyethylene liner dissociation without gross evidence of wear (2 hips). CONCLUSIONS: High wear rates and femoral and acetabular osteolysis have been and still are the main problems in uncemented total hip replacement. There is clear relationship between wear and acetabular osteolysis or loosening of the prostheses. The poor long-term results with these uncemented total hip arthroplasties illustrate the necessity of regular radiographic evaluation in order to detect osteolysis and liner failure, which are both generally asymptomatic until catastrophic failure appears.

[Clinical character and treatment of coexistence of cervical spine disease and lumbar spine degenerative disease].

OBJECTIVE: To investigate the clinical character and surgical management in coexistence of cervical and lumbar spine disease. METHODS: 53 cases with coexistence of cervical and lumbar spine disease were analyzed for clinical character and follow-up outcomes. 19 single cervical operation cases, 16 single lumbar operation cases and 7 combined cervical lumbar operation cases, all patients were recorded with JOA score. RESULTS: The cases with cervical and lumbar intervertebral disc showed at least 2 segments. After 6 months follow-up, 35/44 cases symptom were relieved obviously, of which 24/35 cases were single operation, relief rate is 75.9%, satisfactory rate is 80.0%; of which 11/35 cases were continuous cervical lumbar operation, relief rate is 78.4%, satisfactory rate is 78.5%. 6/44 cases' symptom with only cervical or only lumbar operation were relieved incompletely, 3/44 cases' symptom with second operation relieved incompletely. 5 cases missed diagnosis on the first operation. 29 cases with responsible focus, of which 25 cases were followed up, relieved obviously, relief rate is 76.5%, satisfactory rate is 96.0%. CONCLUSION: The cases with cervical and lumbar intervertebral disc showed at least 2 segments, the same basis of the spinal canal stenosis and disc herniation is degeneration of spine. certain responsible focus and correct surgical management can get good treatment results.