A conservative femoral replacement for total hip arthroplasty

Abstract

Between 1985 and 1993, 146 patients (162 hips) had total hip replacement (THR) using a conservative uncemented femoral component. The mean age of the patients was 50.8 years and the mean follow-up was 6.2 years (2 to 13). One patient was lost to follow-up, one died within two years of surgery and one had a revision procedure after a fracture sustained in a road-traffic accident.For the remaining 159, Kaplan-Meier survival analysis was calculated for the incidence of revision because of mechanical loosening or osteolysis. Survival without mechanical loosening at both five and ten years was 98.2%. Survival without osteolysis was 99% at five and 91% at ten years. The Harris hip score improved from a mean of 66.3 before to 90.4 at follow-up. Of particular note is the lack of thigh pain in this group. Radiological analysis showed that 139 stems (88%) had no measurable subsidence, 8 (5%) had less than 2 mm and 12 (7%) had more than 2 mm. Two of the eight and one of the 12 were revised for mechanical loosening. Nine hips were revised for late loosening associated with osteolysis. No reaming of the femoral canal was associated with statistically significant less blood loss compared with a comparable control group of uncemented implants (p < 0.0001).Our study suggests that using a conservative femoral implant does not protect against wear debris but the reliable mechanical stability (98.2%) makes this an attractive design of implant particularly for young patients.

Periprosthetic proximal bone loss after uncemented hip arthroplasty is related to stem size: DXA measurements in 138 patients followed for 2–7 years

“…A well-fixed stem distally seems to cause stress-shielding, with proximal bone resorption (Engh et al 1992, Kilgus et al 1993. Prosthetic designs with only proximal coating (Khalily and Whiteside 1998), iso-elastic materials (Jacobsson et al 1993, Ang et al 1997) and short femoral components (Morrey et al 2000) have all been designed to reduce this remodeling.…”

Frequent Femoral Neck Osteolysis With Birmingham Mid-head Resection Resurfacing Arthroplasty in Young Patients

“…It differs from other neck-preserving prostheses in that its resection level runs through the middle of the femoral head rather than the head-neck junction. This design sought to overcome the problems of other short-stemmed hip implants, especially proximal femoral neck stress-shielding [7,18,23,30,35,36,38,45]. In this study we set out to assess the performance of BMHR at mid-term followup.…”

“…Patients' median OHS (using the 48-point OHS) improved from 26 (range, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] preoperatively to 46 (range, [35][36][37][38][39][40][41][42][43][44][45][46][47][48], and UCLA score improved from 5 (range, 2-8) to 8 (range, 4-10) at latest review (paired t-test p \ 0.001 for both). There was no difference in median [35][36][37][38][39][40][41][42][43][44][45][46][47][48] or in the median postoperative UCLA scores between males (8; range, 5-10) and females (8; range, 4-10) (Mann-Whitney U p = 0.293 and p = 0.115, respectively).…”

“…There was no difference in median [35][36][37][38][39][40][41][42][43][44][45][46][47][48] or in the median postoperative UCLA scores between males (8; range, 5-10) and females (8; range, 4-10) (Mann-Whitney U p = 0.293 and p = 0.115, respectively).…”

“…It differs from other neck-preserving prostheses in that its resection level runs through the middle of the femoral head rather than the head-neck junction. Allowing the load to go through the conically shaped headneck junction would theoretically prevent stress shielding in the femoral neck [15,35,36], a complication reported in other neck-preserving hip implants [7,18,23,30,38,45].…”