ObjectiveTo investigate the effects of the femoral head size on the linear wear rate of highly crosslinked polyethylene (HXLPE) l iner in total hip arthroplasty (THA). MethodsA retrospective analysis was performed on the cl inical data of 41 patients (43 hi ps) who underwent primary THA with HXLPE liner and different sizes of femoral heads between January 2004 and December 2007 for hip diseases. There were 22 males (23 hi ps) and 19 females (20 hi ps) with a mean age of 60.2 years (range, 35-89 years), including femoral neck fracture (26 hi ps), avascular necrosis of femoral head (8 hi ps), osteoarthritis (5 hi ps), rheumatoid arthritis (2 hi ps), and congenital hip dysplasia (2 hi ps). According to the size of the femoral head, the patients were divided into 2 groups: standard head size (26 and 28 mm) was used in 25 cases (26 hi ps, group A) and big head size (32, 36, and 40 mm) in 16 cases (17 hi ps, group B). The cumulative penetration of the femoral head, linear wear rate, and effectiveness were evaluated and compared between 2 groups. ResultsAll the incisions healed by first intention, no complications of infection, deep vein thrombosis, or nerve injury occurred. The patients were followed up 5-9 years (mean, 5.7 years). No two-stage revision was needed. Harris score was significantly improved at 3 months, 6 months, and 1, 2, 3, 4, and 5 years after operation when compared with preoperative score in each group (P < 0.05), but no significant difference was found between different time points after operation in 2 groups (P > 0.05), and between 2 groups at each time point (P > 0.05). Acetabular abduction angle was (31.4±3.8)° in group A and (32.3±4.1)° in group B, showing no significant difference (t=0.482, P=0.621). At last follow-up, no radiographic or cl inical loosening was observed in each group. At 5 years after operation, X-ray results of acetabular components showed radiolucent line ( < 1 mm) in 1 case (1 hi p) and 1 case (1 hi p) of 2 groups respectively; but X-ray results of femoral components showed no radiolucent line. There was no significant difference in the cumulative penetration of the femoral head between 2 groups at 1, 2, 3, 4, and 5 years after operation (P > 0.05). The linear wear rate was (0.026±0.007) mm/year in group A and (0.025±0.007) mm/year in group B, showing no significant difference between 2 groups (t=0.708, P=0.483). ConclusionNo association is found between femoral head size and the linear wear rate of HXLPE liner. It is an ideal interface of THA because of its low linear wear rate.
ObjectiveTo evaluate the clinical results of uncemented total hip arthroplasty (THA) for ultimate hip disease combined with proximal femoral deformity. MethodsBetween February 2005 and June 2013, 48 cases (51 hips) of ultimate hip disease combined with proximal femoral deformity were treated with uncemented THA and osteotomy. There were 14 males (16 hips) and 34 females (35 hips), with an average age of 52 years (range, 19-83 years). Unilateral hip was involved in 45 cases, and bilateral hips in 3 cases. There were 36 cases (39 hips) of developmental dysplasia of hip, 3 cases (3 hips) of traumatic arthritis, 1 case (1 hip) of previous intertrochanteric valgus osteotomy, 4 cases (4 hips) of internal fixation failure, 3 cases (3 hips) of tuberculosis, and 1 case (1 hip) of suppurative infection. Preoperative Trendelenburg sign was positive in all hips. The discrepancy of limbs was observed in 19 patients. According to Berry classification system, deformity located at the greater trochanter in 4 hips, at the femoral neck in 39 hips, at the femur metaphysis in 7 hips, and at femoral shaft in 1 hip. The Harris score was 34.28±3.28 before operation. ResultsHealing of incision by first intention was obtained in all patients. Deep venous thrombosis occurred in 1 patient, and no complications of infection, neurovascular injury, or prosthetic dislocation were found. Forty-seven patients (50 hips) were followed up 3.8 years on average (range, 1-9 years). At last follow-up, the Harris hip score was 92.87±4.57, showing significant difference when compared to preoperative score (t=-213.19, P=0.00). Postoperative Trendelenburg sign was positive in 6 hips. Normal gait was shown in 39 cases, and slight limp in 8 cases. X-ray film results showed complete correction of deformity and bony fusion at the osteotomy sites at 3 to 6 months (mean, 4.4 months) after operation. At last follow-up, all the femoral and acetabulum components showed radiographic evidence of bone ingrowth. Osteolysis was observed in Gruen zones 1 and 7 around the femoral prosthesis of 2 cases. There was no case of prosthesis loosening. ConclusionThe biological fixation of the femoral stem prosthesis combined with corrective osteotomy can attain satisfactory result for ultimate hip disease combined with proximal femoral deformity in THA.
ObjectiveTo analyze the mid-and long-term effectiveness of the 3rd-generation ceramic-on-ceramic (CoC) total hip arthroplasty (THA) in the younger patients. MethodsA retrospective analysis was made on the clinical data of 68 younger patients (73 hips) who accepted the 3rd-generation CoC THA between March 2001 and May 2009. Of 68 cases, 39 was male and 29 was female with the average age of 38.6 years (range, 18-50 years); there were 15 cases (15 hips) of osteonecrosis of the femoral head, 9 cases (9 hips) congenital dysplasia of the hip, 5 cases (8 hips) of ankylosing spondylitis, 10 cases (10 hips) of osteoarthritis of the hip joint, 12 cases (12 hips) of traumatic hip arthritis, 12 cases (12 hips) of femoral neck fracture, 4 cases (6 hips) of rheumatoid hip arthritis, and 1 case (1 hip) of tumor of the femoral neck. The Harris score and University of California Los Angeles (UCLA) score were used to evaluate the hip joint function and activity level respectively. The visual analogue scale (VAS) was used to assess postoperative thigh pain. Radiological signs of osteolysis, loosening, and alumina ceramic related complications were evaluated continuously. And the KaplanMeier survival analysis was used to assess the prosthesis survival. ResultsThe average duration of follow-up was 9.7 years (range, 6-14 years). Sandwich ceramic liners fracture was observed in 3 cases (3 hips), and revision was performed; 1 case had "squeaking" hip because of physical activity. At last follow-up, Harris score and UCLA score were significantly improved when compared with preoperative scores (P<0.05). Bony healing was obtained in all patients, without osteolysis, loosening, and thigh pain. The VAS score was 0. The 5-year and 10-year cumulative survival rates for ceramic fracture revision were 98.6% and 95.9%, and the 5-year and 10-year cumulative survival rates for osteolysis and loosening revision both were 100%. ConclusionThe 3rd-generation CoC prosthesis offer an excellent option for younger patients in THA and the mid-and long-term effectiveness are satisfactory.