No abstract

Background Impaction bone grafting has been used for acetabular reconstruction in revision surgery. However, most series do not establish differences in survival in revisions with differing severity of bone loss. Questions/purposes We therefore determined (1) the survival rate for rerevision associated with varying degrees of bone loss; (2) the frequency with which bone graft resorption occurred; and (3) whether the reconstruction restored the anatomic center of rotation of the hip. Methods We retrospectively reviewed 165 patients (181 hips) who underwent rerevision for major bone loss. Using the classification of Paprosky et al. 98 hips had a Grade 3A defect and 83 a Grade 3B. We determined survival rates for revision and graft resorption. Cup position was determined measuring vertical and horizontal positions and the distance from the center of the prosthetic femoral head to the normal center of rotation of the hip in both groups according to Ranawat. The minimum followup until rerevision or the latest evaluation was 0.3 years months (mean, 7.5 years; range, 0.3-17.7 years). Results The survival rate for revision at 8 years was 84% (95% confidence interval: 61-100) for Grade 3A and 82% (95% confidence interval: 68-100) for Grade 3B. Twelve hips were rerevised. Seventeen grafts showed bone resorption. Acetabular cup position was anatomically restored in both Grades 3A and 3B. Conclusions The midterm results for impacted bone allograft and cemented all-polyethylene cups were similar in both Grade 3A and Grade 3B hips. Acetabular reconstruction allows anatomic positioning of the cups and is associated with a low rate of rerevision.

Level II, prognostic study. See Instructions for Authors for a complete description of levels of evidence.

Between 1999 and 2001, 90 patients underwent total hip replacement using the same uncemented acetabular and femoral components with a 28 mm metallic femoral head but with prospective randomisation of the acetabular liner to either Durasul highly cross-linked polyethylene or nitrogen-sterilised Sulene polyethylene. We assessed 83 patients at a minimum follow-up of ten years. Linear penetration of the femoral head was estimated at six weeks, six and 12 months and annually thereafter, using the Dorr method, given the non-spherical shape of the acetabular component. There was no loosening of any component; only one hip in the Sulene group showed proximal femoral osteolysis. The mean penetration of the femoral head at six weeks was 0.08 mm (0.02 to 0.15) for the Durasul group and 0.16 mm (0.05 to 0.28) for the Sulene group (p = 0.001). The mean yearly linear penetration was 64.8% lower for the Durasul group at 0.05 mm/year (sd 0.035) for the Sulene group and 0.02 mm/year (sd 0.016) for the Durasul (p < 0.001). Mean linear femoral head penetration at ten years was 61% less in the Durasul than Sulene group. Highly cross-linked polyethylene gives excellent results at ten years.

With the standard BMC technique performed without monitoring the number of progenitors in the concentrate, we are uncertain to observe a significant decrease in femoral head collapse compared to CD alone. Improved outcomes may require the monitoring of progenitor cells injected into the femoral head, particularly in large lesions.

No abstract

Total hip arthroplasty (THA) in young patients has a high loosening rate, due in part to acetabular deformities that may compromise bone fixation and polyethylene wear. We therefore asked whether wear or osteolysis and loosening differ in patients under 40 years of age with alumina-on-alumina THA compared to those who are older. We prospectively followed 56 patients (63 hips) younger than 40 years (Group 1) and 247 patients (274 hips) older than 40 (Group 2) who had an alumina-on-alumina THA. The minimum followup was 4 years (mean, 5.6 years; range, 4-9 years). The two groups differed in various features: there were no patients with primary osteoarthritis in Group 1 and they had worse preoperative function and range of mobility, while weight, activity level, and implant size were greater in Group 2. The survival rate for cup loosening at 80 months postsurgery was 90.8% (95% confidence interval, 82.9-98.6%) for Group 1 and 96.5% (95% confidence interval, 94.2-98.7%) for Group 2. Cup loosening was less frequent with primary osteoarthritis than with severe developmental dysplasia of the hip. Although an alumina-on-alumina THA provided similar midterm survival and radiographic loosening in both age groups, the preoperative diagnosis seems more important than age for outcome. Continued followup will be required to determine if the alumina-on-alumina bearings in young patients result less risk of osteolysis and loosening.

We report the results of 79 patients (81 hips) who underwent impaction grafting at revision hip replacement using the Exeter femoral stem. Their mean age was 64 years (31 to 83). According to the Endoklinik classification, 20 hips had a type 2 bone defect, 40 had type 3, and 21 had type 4. The mean follow-up for unrevised stems was 10.4 years (5 to 17). There were 12 re-operations due to intra- and post-operative fractures, infection (one hip) and aseptic loosening (one hip). All re-operations affected type 3 (6 hips) and 4 (6 hips) bone defects. The survival rate for re-operation for any cause was 100% for type 2, 81.2% (95% confidence interval (CI) 67.1 to 95.3) for type 3, and 70.8% (95% CI 51.1 to 90.5) for type 4 defects at 14 years. The survival rate with further revision for aseptic loosening as the end point was 98.6% (95% CI 95.8 to 100). The final clinical score was higher for patients with type 2 bone defects than type 4 regarding pain, function and range of movement. Limp was most frequent in the type 4 group (p < 0.001). The mean subsidence of the stem was 2.3 mm (SD 3.7) for hips with a type 2 defect, 4.3 mm (SD 7.2) for type 3 and 9.6 mm (SD 10.8) for type 4 (p = 0.022). The impacted bone grafting technique has good clinical results in femoral revision. However, major bone defects affect clinical outcome and also result in more operative complications.