Alendronate reduces periprosthetic bone loss after uncemented primary total hip arthroplasty - a 5-year follow-up of 16 patients.

BACKGROUND AND AIMS: Periprosthetic bone loss, especially in the proximal part of the femur, is common after cemented and uncemented total hip arthroplasty (THA). Short-term studies suggest that bisphosponates can minimize this bone loss related to stress-shielding phenomenon. The aim of the present randomized study was to investigate whether the positive effect of a 6 months alendronate treatment postoperatively still exists at five-year follow up. MATERIALS AND METHODS: Sixteen uncemented primary THA patients were randomized to receive either 10mg alendronate + 500 mg calcium (n = 7) or 500 mg calcium only (n = 9) daily for 6 months postoperatively. Periprosthetic bone mineral density (BMD) was measured with the dual X-ray absorptiometry (DXA) postoperatively and at 6, 12, 24, 36 and 60 months follow-up. RESULTS: At the 5-year follow up, the calcium group showed mean BMD decreases of 23.1% (SD 14.6) in the proximal part of the femur (prROI) and 9.6% (SD 14.9) in total femoral regions of interest (totROI). In the alendronate group the corresponding BMD decreases were 13.6% (SD 19.0) and 3.9% (SD 7.6) respectively. The positive effect of alendronate was already demonstrated during the first six months postoperatively. Subsequently the bone loss was equal in both groups, and the 5-year BMD changes were not significantly different between the groups. CONCLUSIONS: Alendronate seems to decrease early periprosthetic bone loss after arthroplasty but this pilot study could not provide enough evidence that the positive effect noted in the early postoperative period is still maintained 5 years after the operation.

Alendronate reduces periprosthetic bone loss after uncemented primary total hip arthroplasty: a prospective randomized study.

Periprosthetic bone loss, especially in the proximal part of the femur, is common after cemented and uncemented total hip arthroplasty (THA). Bone loss can be progressive and, in the extreme, may threaten survival of the prosthesis. To study whether alendronate therapy can reduce bone loss adjacent to prostheses, 13 uncemented primary THA patients were randomized to the study. They received 10 mg alendronate + 500 mg calcium (n = 8) or 500 mg calcium only (n = 5) daily for 6 months follow-up after THA. Periprosthetic bone mineral density (BMD) was measured with dual energy X-ray absorptiometry (DXA). Decreases in periprosthetic BMD in the alendronate-treated group were lower compared with the changes in the calcium-only group in the same regions of interest at the same follow-up time. In the proximal femur, the mean BMD decrease was 17.1% in the calcium-only group, whereas in the alendronate-treated group the decrease was only 0.9% (p = 0.019). The mean periprosthetic BMD change was also significantly different in the total periprosthetic area between the study groups at the end of the follow-up (calcium-only group -9.9% vs. alendronate-treated group -2.6%; p = 0.019). Alendronate therapy led to a significant reduction in periprosthetic bone loss after primary uncemented THA compared with the changes found in patients without therapy. This kind of bone response may improve the support of the prosthesis and may result in better survival of the prosthesis. However, in this study the follow-up time was too short and the study population was too small to make any long-term conclusions as to the prognosis for THA patients treated with alendronate.

Monitoring of periprosthetic BMD after uncemented total hip arthroplasty with dual-energy X-ray absorptiometry--a 3-year follow-up study.

Insertion of a metallic implant into the femur changes bone loading conditions and results in remodeling of femoral bone. To quantify changes in bone mass after uncemented total hip arthroplasty (THA), we monitored femoral bone with dual-energy X-ray absorptiometry (DXA). The periprosthetic bone mineral density (BMD) was measured with Lunar DPX densitometry in seven Gruen zones and the total periprosthetic area at scheduled time intervals in 22 patients during a 3-year follow-up. BMD decreased significantly almost in all Gruen zones during the first 3 months, ranging from 3.4% to 14.4% (p < 0.05 top < 0.001). At the end of the first year, the most remarkable decrease in BMD was found in the calcar (zone 7; -22.9%). During the second postoperative year, a slight restoration of periprosthetic bone mass was recorded. During the third year, no significant changes in BMD were found. The preoperative BMD was the only factor that was significantly related to the periprosthetic bone loss. Clearly, the early periprosthetic bone loss noticed during the 3 months after THA is caused by mainly limited weight bearing to the operated hip and stress shielding. We suggest that the restoration of bone mass is a sign of successful osteointegration between bone and metallic implant. DXA is a suitable tool to follow the bone response to prosthetization and will increase our knowledge on the behavior of bone after THA.

Factors influencing the success of microsurgery for distal tubal occlusion.

Ninety-three infertile women with distal tubal occlusion were subjected to salpingostomy in 1982-1984. In 78 of them follow-up data were available for 2-5 years. Second look laparoscopy was performed in 47 patients at a median of 4 months postoperatively. It showed one or both tubes patent in 45 (96%). In the total series of 93 patients, 13% had live births, 7.5% spontaneous abortions, and 13% ectopic pregnancies. Severe adnexal adhesions and the extent of fimbrial damage found at operation or at second look laparoscopy were the most significant factors related to the poor outcome of microsurgery. Our experience suggests that cases with severe adhesions and poor tubal status should be primarily directed to in vitro fertilization program rather than to microsurgery.