全髋关节表面置换术后股骨近端骨密度的变化

目的评价全髋关节表面置换术对股骨近端骨量变化的影响。方法2002年7月至2005年6月,对行全髋关节表面置换术（表面置换组）和人工全髋关节置换术（全髋置换组）各26例患者作为研究对象,均在术前、术后3、6、12和24个月时对股骨近端按Gruen分区设为7个测量感兴趣区,表面置换组加股骨颈外上和内下区,应用双能X线吸收测定仪测定骨密度,比较两组术前和术后股骨近端骨密度变化。结果术后3、6、12和24个月时,表面置换组股骨近端骨密度分别降低5．8％、4．9％、2．6％和0．4％;测量感兴趣区1的骨密度术后6个月时降至89．7％,至24个月时增至103．8％;测量感兴趣区7的骨密度术后6个月时降至95．1％,24个月时增至103．7％;股骨颈部骨密度在术后6个月时即可恢复至术前水平,股骨颈外上区的骨密度术后3个月时降至97．1％,术后24个月时增至107．4％（P〈0．05）;股骨颈内下区的骨密度术后24个月时增至117．9％（P〈0．05）。全髋置换组股骨近端骨密度分别降低7．0％、10．6％、1．0％和4．1％。测量感兴趣区1的骨密度术后6个月降至90．8％,术后24个月时为94．4％;测量感兴趣区7术后3个月降至94．2％,术后24个月时为96．7％。结论全髋关节表面置换术后股骨近端骨量可以得到有效保存和恢复。     

Cyclic therapy with etidronate has a therapeutic effect against local osteoporosis after cementless total hip arthroplasty

Proximal bone resorption around the femoral stem is one of the major complications of cementless total hip arthroplasty (THA). The potential complications resulting from proximal bone resorption include femoral fracture and late stem loosening. The purpose of this study was to evaluate the effects of cyclic therapy with etidronate on periprosthetic bone mineral density (BMD) after cementless THA. Fifty-two patients who had undergone cementless THA were randomized for this study. Group A consisted of 30 hips in 29 patients without osteoactive drugs. Group B consisted of 23 hips in 23 patients with cyclic therapy with etidronate (i.e., 400 mg/day of oral etidronate for 2 weeks followed by 12 weeks of 500 mg/day of calcium lactate and repeated every 14 weeks), one of whom was excluded from the study because of side effects attributed to the drug. Periprosthetic BMD in seven regions of interest based on the zones of Gruen et al. (Clin. Orthop. 141 (1979), 17-27) was measured with dual energy X-ray absorptiometry (DXA) at 3 weeks, 6 months, and 12 months postoperatively. The postoperative decreases of BMD in group B were significantly lower than those in group A in zones 1 and 7 (P < 0.05 and P < 0.05, respectively) at 6 months and in zones 1, 2, 6, and 7 (P < 0.05, P < 0.05, P < 0.05, and P < 0.001, respectively) at 12 months. The BMD change appeared to be stabilized at 6 months in all zones in group B, while in group A there was a progressive decrease of average BMD (6.1%) in zone 7 between 6 months and 12 months. These findings suggested that cyclic therapy with etidronate may help to reduce the resorptive changes in the proximal part of the femur after cementless THA. Further follow-up study with larger populations will be required to define the potential efficacy of intermittent cyclic etidronate therapy on postoperative bone loss.     

Restoration of proximal periprosthetic bone loss by denosumab in cementless total hip arthroplasty

Summary

Denosumab contributed to the restoration of proximal periprosthetic bone loss around the femoral stem that were measured using a DEXA, especially in zone 7, at 1 year after cementless THA in elderly osteoporotic patients.

Introduction

Although bone quality is an important issue in elderly osteoporotic patients who underwent total hip arthroplasty (THA) with a cementless stem, periprosthetic bone mineral density (BMD) in the proximal femur has been reported to be decreased by 15–40% postoperatively. Some authors have examined the use of several types of bisphosphonates to prevent decreases in BMD in the proximal femur after cementless THA; however, few reports have demonstrated success in restoring BMD in the proximal medial femoral bone, such as zone 7.

Methods

We conducted prospective study comparing patients who underwent cementless THA administered with denosumab (10 patients) and without denosumab (10 patients). BMD around the femoral stem were measured using a DEXA immediately after surgery, and at 6 months and at 1 year after surgery. No difference was found between the two groups referred to the patient’s demographic data.

Results

We found that denosumab displayed definitive effects in increasing the % change in periprosthetic BMD at zone 7 by an average of 7.3% in patients with cementless THA, compared to control group who were given only vitamin D.

Conclusion

Denosumab is one of a number of anti-osteoporotic agents to have a definitive effect on the restoration of proximal periprosthetic bone loss, especially in zone 7, after cementless THA. Denosumab contributed to the restoration of decreased periprosthetic BMD to normal levels. As the decrease in BMD in the proximal femur after THA is considered to be apparent at 6–12 months after surgery, it is believed that prevention of the deterioration of bone quality is important in the proximal femur immediately after cementless THA for elderly female patients with osteoporosis.

     

Periprosthetic bone loss after cemented total hip arthroplasty

In this prospective 5-year study, we determined the periprosthetic bone loss after cemented total hip arthroplasty (THA) in 15 patients using dual energy X-ray absorptiometry (DXA). A reduction in the periprosthetic bone mineral density (BMD) of 5-18% occurred in all Gruen regions, or regions of interest (ROI), during the first 3 months after THA. The bone loss continued up to 6 months in almost all ROIs. From 1 to 5 years, we found only minor changes in BMD in periprosthetic bone. After the follow-up, the mean greatest bone loss (26%) was seen in the femoral calcar area. The reduction in mean BMD was 5% in men, and 16% in women. The lower the preoperative BMD, the higher was the postoperative bone loss. We found that after the phase of acute bone loss, further loss was minimal, reflecting merely the normal ageing of bone after uncomplicated THA.     

Changes in bone mineral density in the proximal femur after hip resurfacing and uncemented total hip replacement: A prospective randomised controlled study

We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p < 0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.     

Changes of the bone mineral density in proximal femur following total hip resurfacing arthroplasty in osteonecrosis of femoral head

Total hip resurfacing arthroplasty (THRA) is being performed with increasing frequency for osteonecrosis of femoral head (ONFH). To evaluate femoral bone remodeling in ONFH after THRA and determine the impact of stem‐neck angle (SNA) of inserted femoral component on bone remodeling, we monitored the changes in BMD in proximal femur in 23 patients with ONFH after surgery. Patients were divided into group A (SNA ≥ 5°) and group B (SNA < 5°). The BMD was measured in seven Gruen zones and two neck zones using dual‐energy X‐ray absorptiometry preoperatively, then at 3, 6, 12, and 24 months after surgery. At all ROIs, the BMD decreased significantly by 3 months postoperatively. The BMD ceased to decrease and reversed by 6 months. The BMD in neck increased significantly in group A, compared with group B at 24 months. The BMD increased 2% at ROI1 at 24 months in both groups, and at ROI7, the BMD in group A reversed to baseline value by 6 months and increased 5.81% at 24 months. These findings implied that the bone stock of proximal femur in ONFH can be well reserved after total hip resurfacing arthroplasty with valgus positioning of the femoral component. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:453–459, 2008     

Risedronate reduces postoperative bone resorption after cementless total hip arthroplasty

Summary Forty-three patients who had undergone cementless THA were randomly assigned to receive no osteoactive drug or oral risedronate for 6 months. Postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1, 2, 3, 6, and 7. Introduction Proximal bone resorption around the femoral stem often has been observed after total hip arthroplasty (THA), could lead to late stem loosening. We previously reported the efficacy of etidronate on periprosthetic bone resorption after cementless THA. Recently risedronate is suggested to be effective for the prevention and treatment of for osteoporosis. The purpose of the present study was to evaluate the effects of risedronate on periprosthetic bone loss after cementless THA. Methods Forty-three patients who had undergone cementless THA were randomly assigned to receive no osteoactive drug (21 patients) or oral risedronate 2.5 mg/day (22 patients) for 6 months. Three patients were eliminated from the risedronate group because of dyspepsia. Periprosthetic bone mineral density (BMD) in seven regions of interest based on the zones of Gruen et al. was measured with dual energy X-ray absorptiometry at 3 weeks and 6 months postoperatively. Results At 6 months after surgery, postoperative decrease of BMD in the risedronate group was significantly lower than that seen in the control group in zones 1, 2, 3, 6, and 7 (p < 0.05, p < 0.01, p < 0.01, p < 0.05, and p < 0.05, respectively). Conclusion These outcomes suggested that risedronate might reduce the periprosthetic bone resorption after cementless THA.     

Femoral neck bone mineral density after resurfacing hip arthroplasty

Introduction: Resurfacing hip arthroplasty (RHA) has been suggested to provide an alternative to conventional total hip arthroplasty in younger, active patients. It seems to have an ability to conserve the bone mass on the femoral side. Some controversy exists regarding to the possible disadvantages of RHA and some of them are connected to poor femoral bone quality after surgery. Hence we wanted to study the bone mineral density changes 3 and 12 months after RHA. Materials and Methods: A total of 26 patients (22 men and 4 women, 28 hips) underwent a hip resurfacing arthroplasty. The mean age of the patients was 55,2 (range 38-69) years. Bone mineral density (BMD) of the proximal femur was measured by using the dual-energy X-ray absorptiometry (DXA) postoperatively and within 3 and 12 months from surgery. For analysis, we divided the femoral neck area into four equal-sized regions of interest ranging from the prosthesis to the trochanter level. Results: At three months follow-up the BMD changes varied between -5.1% (ROI C) and + 1.9% (ROI A), as compared with the immediate postoperative values. After one year follow-up the BMD changes were + 1.1% in the ROI A, + 5.4% in the ROI B, -3.9% in the ROI C and + 1.3% in the ROI D. The changes in BMD were not statistically significant. Discussion: While there is still much debate and room for additional research in this topic, the results suggest that BMD is conserved in the femoral neck one year after hip resurfacing arthroplasty.     

非骨水泥全髋关节置换术治疗股骨头缺血性坏死的疗效观察

[目的]对使用非骨水泥全髋关节置换术治疗股骨头缺血性坏死的患者进行临床及影像学随访,探讨其疗效、并发症及其影响因素。[方法]选取2000年3月~2007年11月以来因股骨头缺血性坏死在本院行非骨水泥全髋关节置换术并具有完整临床及影像资料的76例(91髋)患者进行随访。临床随访包括术前术后Harris评分及各种并发症。影像学评估包括双侧髋关节正位、患髋侧位片,判断股骨及髋臼假体的位置及其周围骨质的变化,并测量髋臼内衬线性磨损量。[结果]截至末次随访时,68例(82髋)获得随访,随访率为90.1%,随访时间平均为48.8个月。术前Harris评分平均为42分(5~86分),末次随访时为93分(53~99分),优良率为90.2%。术后1例患者发生与活动相关的大腿痛,影像学上9髋股骨假体发生早期不稳定,14髋发生应力遮挡,5髋发生异位骨化。无假体松动或翻修病例。[结论]非骨水泥全髋关节置换术治疗晚期股骨头缺血性坏死疗效确切,但存在一过性大腿痛、应力遮挡、异位骨化、假体磨损等并发症,故需长期随访。     

Simultaneous bilateral total hip arthroplasty with a cementless femoral stem

Simultaneous bilateral total hip arthroplasty (THA) is an increasingly common procedure. Although use of a cementless stem can eliminate cement complications, some surgeons limit application of cementless THA because of concerns about early implant loosening. In this article, we report on 30 cementless THA cases (15 patients) followed up for a minimum of 2 years (range, 26-50 months). Despite 73% of femoral bone being type B or type C, all stems showed stable bone ingrowth fixation and no evidence of subsidence. Polyethylene wear rates (left, 0.154 mm/y; right, 0.114 mm/y) did not differ significantly. The excellent clinical results obtained with simultaneous bilateral cementless THA are comparable with those obtained with unilateral THA.     

Changes in tibial bone mass after primary cementless and revision cementless total hip arthroplasty in canine models

The purpose of this study was to examine right-left differences in tibial bone mass after unilateral (left) cementless total hip arthroplasty (THA). Of 39 dogs with THAs, 9 had primary cementless porous-coated femoral stems for 6 months and 15 had similar stems for 2 years. Five dogs had aseptically failed cemented hips, and 10 had aseptically failed cemented hips that were revised with cementless porous-coated femoral stems (5 without bone graft and 5 with autogenous bone graft). These animals were sacrificed 6 months after the revision surgery. The primary cementless dogs showed no right-left difference in tibial bone mineral content (BMC) or cortical bone cross-sectional geometry after 6 months, but after 2 years there was a distal right-left difference in BMC of 6% caused by expansion of the medullary canal in the tibia of the operated limb. Tibial BMC was more than 20% lower in the operated limb of the failed cemented dogs, approximately 15% lower in the nongrafted group, and 7% lower in the grafted group. The right-left tibial difference in BMC in the 2-year primary cementless group is most probably because of subclinical disuse of the operated limb. Among the dogs with failed cemented stems, the lower right-left difference in the two revised groups compared with the non-revised group suggests that improved limb function after cementless revision THA may cause gain of previously lost bone.     

Periprosthetic bone loss after cemented total hip arthroplasty: a prospective 5-year dual energy radiographic absorptiometry study of 15 patients

In this prospective 5-year study, we determined the periprosthetic bone loss after cemented total hip arthroplasty (THA) in 15 patients using dual energy X-ray absorptiometry (DXA). A reduction in the periprosthetic bone mineral density (BMD) of 5-18% occurred in all Gruen regions, or regions of interest (ROI), during the first 3 months after THA. The bone loss continued up to 6 months in almost all ROIs. From 1 to 5 years, we found only minor changes in BMD in periprosthetic bone. After the follow-up, the mean greatest bone loss (26%) was seen in the femoral calcar area. The reduction in mean BMD was 5% in men, and 16% in women. The lower the preoperative BMD, the higher was the postoperative bone loss. We found that after the phase of acute bone loss, further loss was minimal, reflecting merely the normal ageing of bone after uncomplicated THA.     

Changes in Bone Mineral Density of the Acetabulum and Proximal Femur After Total Hip Resurfacing Arthroplasty

Our aim was to investigate the changes in bone mineral density (BMD) of acetabulum and proximal femur after total hip resurfacing arthroplasty. A comparative study was carried out on 51 hips in 48 patients. Group A consisted of 25 patients (26 hips) who had undergone total hip resurfacing and group B consisted of 23 patients (25 hips) who had had large-diameter metal-on-metal total hip arthroplasty (THA). BMDs around the acetabulum and proximal femur were measured using dual-energy x-ray absorptiometry (DEXA) at 2 weeks, 6 months, 1 year and annually thereafter during the 3 years after surgery. At final follow-up, the acetabular net mean BMD decreased by 11% in group A and 10% in group B with no differences between two groups (P = .35). For the femoral side, in Gruen zone 1, the mean BMD increased by 4% in group A, whereas it decreased by 11% in group B (P = .029). In Gruen zone 7, the mean BMD increased by 8% at the final follow-up in group A, whereas it decreased by 13% in group B (P = .02). In both groups the mean BMD increased by 3% in Gruen zones 3, 4, 5, and 6. Stress-related bone loss of the acetabulum was comparable for MOM THA and resurfacing devices, but proximal femoral bone density increased in the resurfacing group and decreased in the THA group.     

Alendronate prevents femoral periprosthetic bone loss following total hip arthroplasty: prospective randomized double-blind study.

Following total hip arthroplasty (THA), femoral periprosthetic bone undergoes a remodeling process that results in bone loss in its proximal regions that may compromise the long-term outcome of THA. Periprosthetic bone loss mainly occurs during the first postoperative months. The question is whether a postoperative treatment with alendronate is effective in reducing periprosthetic bone loss and which doses and duration of treatment are required. In a 12-month prospective, randomized double-blind study, 51 patients undergoing cementless THA were treated postoperatively either with a daily dose of 20 mg alendronate for 2 months and 10 mg for 2 months thereafter (group I), with 20 mg of alendronate for 2 months and 10 mg for 4 months thereafter (group II), or treated with placebo (group III). Proximal femoral bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry (DEXA) and serum biochemical markers of bone turnover bone specific alkaline phosphatase, osteocalcin, and C-terminal telopeptides (CTX-I) were assayed. Six months of alendronate treatment significantly reduced (p<0.001) bone loss in proximal medial region (-10%) compared with placebo (-26%). All biochemical markers of bone turnover were suppressed by alendronate. These data suggest that alendronate administered for the first 6 postoperative months following THA was effective in preventing early periprosthetic bone loss.     

生物型和骨水泥型股骨假体全髋关节置换术治疗老年骨质疏松性股骨颈骨折的临床效果对比

目的：对比老年骨质疏松股骨颈骨折使用生物型股骨假体柄与骨水泥型股骨假体柄行全髋关节置换术治疗效果。方法对本组进行老年骨质疏松股骨颈骨折100例（100髋）进行的全髋关节置换术根据手术方式分为A组（股骨假体柄骨水泥型全髋关节置换术,60髋）, B组（股骨假体柄生物型全髋关节置换术,40髋）。对比两组髋关节功能、关节活动度、髋关节影像学特点及术后疼痛情况。结果老年骨质疏松股骨颈骨折行全髋关节置换术,采用生物型股骨假体柄与骨水泥型股骨假体柄的全髋关节置换术临床疗效对比差异显著（ P＜0.05）。结论对于老年骨质疏松股骨颈骨折行全髋关节置换术,应用骨水泥型者股骨假体柄术后近期疗效明显优于生物型,但它有诱发深静脉血栓栓塞和骨水泥危象的风险。     

Bone mineral density and biochemical markers of bone turnover in aseptic loosening after total hip arthroplasty.

The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6+/-4.3 (mean+/-SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant (n=17) compared to those (n=32) with fixed femoral implants (P<0.05 all comparisons). This BMD difference was greatest (-31%, P=0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N-telopeptides of type-I collagen (P=0.02) than those with a fixed femoral implant. No differences in pelvic BMD or bone turnover markers were found between subjects with loose (n=18) versus fixed (n=31) pelvic implants.This study suggests that failure of femoral components after cemented THA is associated with region-specific decreases in BMD and an increase in urinary excretion of N-telopeptide cross-links of type-I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological.     

The use of a hydroxyapatite-coated primary stem in revision total hip arthroplasty

Proximal ingrowth of femoral components in total hip arthroplasty (THA) is desirable because it minimizes proximal stress shielding associated with distal ingrowth stems and maximizes bone stock. This is a retrospective evaluation of initial results of revision THA using a proximally hydroxyapatite-coated femoral stem nominally designed for primary use. Patients requiring femoral stem revision were included if they had sufficient femoral bone stock to support a proximally fixed prosthesis (n = 33). This represents 53% of the femoral revisions performed during the period of the study. The average follow-up was 5 years (range 48-88 months). The mean Harris hip and Oxford hip scores were 86.5 and 25.2, respectively. Radiographically, 100% of the stems demonstrated bone ingrowth fixation. These results are superior to previous reports of primary cementless stems for revision THA. The use of a cementless nonmodular implant provides a viable option in some patients undergoing revision THA.     

髋臼内陷症的全髋关节置换术

目的 探讨全髋关节置换术治疗髋臼内陷症的手术操作方法和临床疗效.方法 2003年6月至2008年5月,采用全髋关节置换术治疗髋臼内陷症31例35髋,男16例18髋,女15例17髋;年龄36～71岁,平均52.2岁.手术均采用后外侧入路,股骨头取出困难时采用逆行取出法,分别处理髋臼环和髋臼底,取自体松质颗粒骨修复骨缺损,采用压配方式植入非骨水泥型全髋关节假体.术后1、3、6、12个月门诊随访,以后每年随访1次,随访时采用Harris髋关节评分评估髋关节功能,摄X线片观察假体是否有松动和再次内陷,植骨是否愈合.结果 全部病例随访19～152个月,平均46.5个月.1例患者术后第2天出现右下肢深静脉血栓,经抗凝处理后痊愈;1例术后2个月出现轻度大腿痛,无特殊处理,术后6个月消失,无其他并发症发生.术前Harris髋关节评分平均(48.9±6.5)分,末次随访增至平均(91.2±5.7)分,较术前平均改善42.3分.X线片显示所有假体均获得骨性稳定,无松动和再次内陷,术后平均6个月植骨愈合.结论 对于内陷髋臼,采用不同于普通全髋关节置换的手术技术,外移髋臼至旋转中心,用植骨修复骨缺损,选择非骨水泥型假体重建髋臼,可获得较好的临床效果,髋臼松动和再次内陷发生率低.

Abstract：

Objective To evaluate the clinical outcome of total hip arthroplasty (THA) for protrusio acetabuli. Methods Between 2003 to 2008, 31 patients(35 hips) with protrusio acetabuli were treated with THA, including 16 males (18 hips) and 15 females (17 hips). The age ranged from 36 to 71 years (average age 52.2 years). The femoral heads were moved out with retrograde method when necessary via posterior-lateral hip incision. The acetabular loops and bottoms were prepared respectively. Auto-bone grafting was used to repair acetabular defects and cementless prostheses were planted with press-fit skills. At follow-up visit,the hip functions were evaluated by Harris score. The loosening, re-protrusion and the union of graft bone was judged by X-ray. Results The mean follow-up was 46.5 months (19-152 months). One patient developed DVT on the second day post-operatively who recovered well after anticoagulation treatment. One patient complained of gentle thigh pain which disappeared at 6 months. No other complication was found. The mean Harris scores had improved from 48.9±6.5 pre-operatively to 91.2±5.7 post-operatively. All prostheses acquired bone stabilization with no sign of loosening and re-protrusion and the grafts bone were healed at a mean 6 months according to X-ray. Conclusion THA with acetabular bone grafting and cementless component for protrusio acetabuli have acquired excellent results and prevented loosening and re-protrusio effectively.     

陈旧性股骨颈骨折的全髋关节置换术

目的 探讨全髋关节置换术(total hip arthroplasty,THA)治疗陈旧性股骨颈骨折的假体选择与技术特点.方法 2001年10月至2006年11月因陈旧性股骨颈骨折接受THA患者60例,男30例,女30例;年龄30～80岁,平均57.5岁.按骨折后经保守治疗(23例)或内固定治疗(37例)分组.比较两组股骨柄使用类型、髓腔张开指数、骨质疏松程度.分析术前、术后肢体长度差、股骨头加长长度及旋转中心位置.结果 4l例获得随访,平均随访时间为18-4个月(2～48个月).(1)保守治疗与内固定治疗组骨水泥型柄使用率分别为61%、27%(P<0.05);术前患侧股骨髓腔张开指数分别为2.62±0.85、3.23±0.68(P<0.05);Barnett指数分别为0.40±0.15、0.48±0.08(P<0.05);股骨距平均长度为(0.9±0.6)cm;(2)53%的患者术前髋臼侧骨质疏松等级患侧大于健侧;术后Delce 1、2、3区出现透光线的患者分别占33%、15%及17%(P<0.05);(3)术前、术后平均肢体长度差分别为(21.8±13.0)mm、(1.5±6.7)mm,股骨头平均加长(5.4±2.2)mm.结论 经内崮定治疗后的患者骨质及形态优于经保守治疗者.内固定组股骨柄易被置于内翻位.陈旧性股骨颈骨折多伴有骨质疏松,易发生过度磨锉,导致髋臼安置上移.骨折后瘢痕组织弹性差,易过度松解而不得不使用加长股骨头颈,因此术中应注意软组织松解的程序和范围.     

股骨假体周围骨密度定量测定

目的 通过双能X线骨密度仪测定不同情况下股骨假体周围的骨密度变化情况,了解骨丢失与股骨假体松动的关系。方法 分为骨水泥固定的股骨假体组、非骨水泥固定的股骨假体组、股骨假体松动组共3个组,采用LUNAR DPXL-L型双能X线骨密度仅(Lunar Corp Wisconsin,USA)及Orthopaedies软件,分析时用Gruen’s 7区法。结果 骨水泥固定的股骨假体组骨丢失为15．1%～29．3%,非骨水泥固定的股骨假体组骨丢失为13．2％～27．9%,股骨假体松动组骨丢失为25．4％～43．4%,3组均是股骨近端骨丢失明显．骨丢失主要发生在术后8年以内。结论 骨水泥固定的股骨假体和非骨水泥固定的股骨假体周周骨密度降低一样,假体松动者假体周围骨丢失明显增加。股骨近端2个以上区域骨丢失大于35％或术后8年以后突然出现明显的骨丢失,考虑有股骨假体松动存在的可能性。