[Treatment of osteoarthritis secondary to acetabular dysplasia by total hip arthroplasty].

OBJECTIVE: To evaluate the flexibility of the treatment of osteoarthritis secondary to acetabular dysplasia by total hip arthroplasty (THA), in which the acetabular component is placed in the true acetabulum and femoral osteotomy is not performed. METHODS: From January 1999 to December 2005, 35 THA procedures were performed in 32 patients with 35 hips, including 6 males with 7 hips and 26 females with 28 hips, with the average age of 53 years (ranging from 28 years to 72 years). On the basis of Crowe classification, type I included 10 patients with 11 hips, type II included 14 patients with 15 hips, type III included 5 patients with 6 hips, and type IV included 3 patients with 3 hips. All patients experienced severe pain and dysfunction. In 19 cases, the leg length discrepancy was from 3 cm to 6 cm. The Harris score was 41.49 +/- 10.13 before the operation. In all procedures, the soft tissue was released entirely and the acetabular component was placed in the true acetabulum, but femoral osteotomy was not performed. RESULTS: The average operation time of unilateral THA was 50 minutes. All patients were given transfusion from 2 U to 4U. All incisions healed at the first stage. After the operation, the leg was lengthened 2-6 cm, and the two legs were equally long. The follow-up lasted for 12 to 60 months. The Harris score was 84.71 +/- 9.34 after the operation, showing statistically significant difference (P < 0.05). According to clinical outcomes and X-ray films, no dislocation, femoral fracture, femoral or sciatic nerve palsy was detected. CONCLUSION: It is effective to use THA procedures for osteoarthritis secondary to acetabular dysplasia. If the soft tissue is released entirely, the leg will be lengthened 4-6 cm without nerve palsy.

[Effect of blocking screws on breakage of interlocking intramedullary nails].

OBJECTIVE: To explore the effect of blocking screws on the breakage of interlocking intramedullary nails. METHODS: From January 2003 to August 2005, 56 patients with fresh and close fracture of long shafts were treated by interlocking intramedullary nails. Among them, there were 32 males and 24 females, including 26 femoral fracture and 30 tibial fracture. Fracture of femoral and tibial shaft was fixed with interlocking intramedullary nails normally in group I (n=32). And long oblique, spiral, proximal or distal fracture of bone shaft was fixed with interlocking intramedullary nails and blocking screws in group II (n=24). RESULTS: All cases were followed up 12 to 21 months (16 months on average). In group I, fracture healing failed and the intramedullary nails broke in 3 cases, breakage site was the middle femoral fracture area in 1 case and the first distal interlocking nail hole in 2 cases of distal 1/3 tibial fracture. Fractures healed 6 to 12 months after operations in the other cases, but more bony callus occurred in fracture area. In group II, fractures healing and good alignment were achieved, and no breakage was found in all 24 cases. CONCLUSION: The use of blocking screws added to interlocking intramedullary nails could improve the stability of fracture areas distinctively, and hence reduce the breakage of intramedullary nails.