唑来膦酸对全髋置换术后假体周围骨密度的影响

目的评价唑来膦酸对骨质疏松患者全髋置换术后假体周围骨密度影响。 方法检索主要数据库从建库至2019年11月10日唑来膦酸对骨质疏松患者全髋置换术后应用并评价假体周围骨密度结局指标的随机对照试验,筛选合格研究进行分析。偏倚风险评价应用Cochrane评价员手册,质量评价应用Jadad评分法。应用Rev Man 5.3软件对假体周围骨密度指标进行Meta分析。 结果符合纳入标准的文献共5篇。Meta分析结果显示,术后3个月假体周围骨密度Gruen 2区均数差(MD)＝0.11,95%可信区间(CI)(0.01,0.21),治疗组与对照组比较,假体周围骨密度Gruen 2区差异有统计学意义(Z ＝2.21,P＝0.03);Gruen 3区MD＝0.11,95%CI (0.01,0.21),治疗组与对照组比较,假体周围骨密度Gruen 3区差异有统计学意义(Z＝2.24,P＝0.03);Gruen 6区MD＝0.12,95%CI(0.04,0.21),治疗组与对照组比较,假体周围骨密度Gruen 6区差异有统计学意义(Z＝2.76,P＝0.006)。术后6个月假体周围骨密度Gruen 1区MD＝0.05,95%CI(0.01,0.09),治疗组与对照组比较,假体周围骨密度Gruen 1区差异有统计学意义(Z＝2.20,P＝0.03);Gruen 2区MD＝0.08,95%CI(0.03,0.14),治疗组与对照组比较,假体周围骨密度Gruen 2区差异有统计学意义(Z＝3.03,P＝0.002);Gruen 3区MD＝0.05,95%CI (0.00,0.10),治疗组与对照组比较,假体周围骨密度Gruen 3区差异有统计学意义(Z＝2.10,P＝0.04);Gruen 4区MD＝0.10,95%CI(0.04,0.15),治疗组与对照组比较,假体周围骨密度Gruen 4区差异有统计学意义(Z＝3.46,P＝0.0005);Gruen 5区MD＝0.08,95% CI(0.03,0.14),治疗组与对照组比较,假体周围骨密度Gruen 5区差异有统计学意义(Z＝2.87,P＝0.004)。术后12个月假体周围骨密度Gruen 1区MD＝0.09,95%CI(0.05,0.14),治疗组与对照组比较,假体周围骨密度Gruen 1区差异有统计学意义(Z＝4.22,P<0.0001);Gruen 2区MD＝0.11,95%CI(0.05,0.16),治疗组与对照组比较,假体周围骨密度Gruen 2区差异有统计学意义(Z＝3.91,P<0.0001);Gruen 3区MD＝0.08,95%CI(0.03,0.13),治疗组与对照组比较,假体周围骨密度Gruen 3区差异有统计学意义(Z＝3.42,P＝0.0006);Gruen 4区MD＝0.15,95%CI(0.09,0.20),治疗组与对照组比较,假体周围骨密度Gruen 4区差异有统计学意义(Z＝5.01,P<0.00001);Gruen 5区MD＝0.10,95%CI(0.05,0.16),治疗组与对照组比较,假体周围骨密度Gruen 5区差异有统计学意义(Z＝3.77,P＝0.0002)。纳入研究均无重大不良反应发生。 结论唑来膦酸能有效延缓全髋置换术后假体周围骨密度的降低,增加假体生物学稳定性,且临床应用安全,但需要更多高质量、多中心严格设计的随机对照试验进一步验证。     

唑来膦酸对绝经后骨质疏松症患者假体周围骨密度的影响

目的研究唑来膦酸对绝经后骨质疏松症患者假体周围骨密度的影响。方法选取2015年11月至2016年4月符合入组标准的32例绝经后骨质疏松症患者,随机分成对照组(16例,年龄74.4岁±5.7岁)和治疗组(16例,年龄73.3岁±6.6岁),进行为期一年的随访研究。于术后1周、3个月、6个月、12个月通过双能X线扫描(DEXA)测定假体周围骨密度值,于术前、术后3个月、6个月、12个月通过血清学检查测定相关骨代谢标志物的水平。结果两组患者术后3个月、6个月、12个月与术后1周(基线)相比,Gruen1-7区骨密度均呈不同程度下降。术后6个月对照组在Gruen1、4、6、7区及术后12个月在Gruen1、2、4、6、7区的骨密度丢失明显高于治疗组。术后3个月、6个月、12个月对照组的骨吸收标志物(β-CTX)水平明显高于治疗组,两组的骨形成标志物(TP1NP)水平仅在术后12个月具有统计学意义(对照组高于治疗组),两组的25(OH)D水平在术后3个月、6个月、12个月均无统计学意义。结论绝经后骨质疏松症妇女行全髋关节置换术后使用5 mg唑来膦酸能有效预防假体周围的骨密度丢失及改善骨的重建。     

唑来膦酸对非骨水泥型全髋假体周围骨密度的早期影响

目的研究唑来膦酸对非骨水泥型全髋术后髋臼及股骨侧假体周围骨密度的早期影响。方法自2013-05—2014-08将50例符合纳入标准的行全髋置换的骨质疏松患者随机分为试验组(术后应用唑来膦酸)与对照组(术后应用生理盐水),试验组于术后10 d注射唑来膦酸5 mg,对照组术后10 d予注射生理盐水100 ml,2组均分别于术后1周、3个月、6个月及1年应用双能X线骨密度仪测定股骨及髋臼假体周围各个分区的骨密度。结果试验组22例获得随访平均23(18~33)个月,对照组23例获得随访平均26(20~35)个月。在术后3个月、6个月及1年,所有患者股骨侧除1区骨密度增加,在股骨假体周围其余各区的骨密度均有不同程度下降;但试验组在7区骨密度于术后6个月及1年时显著高于对照组,差异有统计学意义(P0.05),在其余各区差异无统计学意义(P0.05)。髋臼假体Ⅰ区骨密度于术后均呈较早期升高,Ⅱ区于术后3个月2组均有轻微上升,之后降低外,Ⅲ区骨密度始终呈下降趋势,试验组在Ⅲ区骨密度于术后6个月及1年时显著高于对照组,差异有统计学意义(P0.05)。其余两区骨密度差异无统计学意义(P0.05)。结论应用唑来膦酸能有效防止非骨水泥型髋臼及股骨假体周围骨量减少。     

短柄股骨假体全髋关节置换术后股骨近端骨改建及有限元分析

目的通过观察股骨假体周围骨密度改变情况来分析短柄股骨假体全髋关节置换术后股骨近端骨改建情况。方法纳入自2011-06—2016-06完成的71例全髋关节置换术,35例(37髋)采用短柄股骨假体(短柄组),36例(37髋)采用常规股骨假体(常规组)。比较两组术后1年疼痛VAS评分、髋关节功能Harris评分、股骨假体周围骨密度。采用有限元法分析两种股骨假体置入后的应力遮挡情况。结果 71例均获得随访,随访时间13～15(13.2±0.8)个月。短柄组与常规组术后1年疼痛VAS评分、髋关节功能Harris评分差异无统计学意义(P0.05)。与术后1周比较,术后1年短柄组股骨假体周围Gruen 1区和5区骨密度无明显变化,Gruen 4区骨密度降低,而Gruen 2、3、6、7区骨密度增加;常规组术后1年股骨假体周围Gruen 1、2、3、5、6、7区骨密度降低,而Gruen 4区骨密度升高。术后1年短柄组股骨假体周围所有Gruen分区骨密度均高于常规组,差异有统计学意义(P0.05)。有限元分析结果显示常规组股骨近端内侧与外侧均出现应力遮挡,而短柄组仅在股骨近端外侧出现应力遮挡。结论短柄股骨假体具有良好的力学传导特性,全髋关节置换术中使用短柄股骨假体可促进股骨近端骨改建并减少应力遮挡。     

阿仑膦酸钠预防非骨水泥型假体周围早期骨丢失的临床研究

目的 探讨阿仑膦酸盐对非骨水泥型人工假体周围早期骨量的影响.方法 50例患者随机分为对照组和治疗组,术后1周对照组予以口服钙尔奇D1片,治疗组予以固邦10mg＋钙尔奇D片.连续服用3周.休息2周.5周为1疗程,连续5个疗程.分别于术后7天、3个月、6个月行假体周围骨密度（DEXA）检测.结果 50例病例中,45例获得完整随访.术后3个月、6个月假体周围骨量（ROI1区和ROI7区）对照组与治疗组相比有显著性差异（P＜0.01）.结论 阿仑膦酸钠能有效预防假体周围早期骨量减少.     

经皮椎体后凸成形术联合唑来膦酸治疗骨质疏松性椎体压缩骨折的疗效观察

目的 观察经皮椎体后凸成形术联合唑来膦酸治疗骨质疏松性胸腰椎压缩骨折的安全性及临床疗效。方法 选取自2019-12—2020-10接受经皮椎体后凸成形术治疗的50例骨质疏松性胸腰椎压缩骨折作为研究对象,纳入术后3 d内接受唑来膦酸治疗的30例作为观察组,单纯采用经皮椎体后凸成形术治疗的20例纳入对照组。比较两组术后疼痛VAS评分、ODI指数、Beck值、伤椎矢状面Cobb角、骨密度。结果 50例术后均获得至少1年随访。观察组静脉滴注唑来膦酸治疗后16例出现发热,7例出现便秘,对症治疗后恢复正常,未出现急性肾功能损伤、下颌骨坏死等并发症。观察组随访期间出现3例（10%）邻近椎体骨折,对照组出现7例（35%）邻近椎体骨折,观察组邻近椎体骨折发生率明显低于对照组,差异有统计学意义（P<0.05）。观察组术后6个月、术后1年骨密度高于对照组,术后1年疼痛VAS评分、ODI指数均低于对照组,差异有统计学意义（P<0.05）;而两组术后第2天、术后1个月、术后6个月、术后1年Beck值、伤椎矢状面Cobb角比较差异无统计学意义（P>0.05）。结论 经皮椎体后凸成形术联合唑来膦酸...     

地舒单抗对绝经后骨质疏松性股骨颈骨折全髋关节置换术后股骨近端假体周围骨密度的影响

目的:研究地舒单抗对绝经后骨质疏松性股骨颈骨折患者全髋关节置换术后(total hip arthroplasty,THA)股骨近端假体周围骨密度的影响。方法:选取2020年10月至2021年10月绝经后女性骨质疏松性股骨颈骨折行THA术后54例,治疗组25例接受地舒单抗治疗,年龄(74.3±6.2)岁;对照组29例未接受地舒单抗治疗,年龄(75.2±4.8)岁。术后1周及3、6及12个月各个时间点,通过双能X线骨密度仪(DEXA型)测定股骨近端假体周围骨密度,并在不同时间点测量骨转换各项指标。结果:术后3、6及12个月对照组的抗酒石酸酸性磷酸酶(tartrate resistant acid phosphatase,TRACP-5b)高于治疗组(P<0.05);对照组术后12个月骨特异性碱性磷酸酶(bone-specific alkaline phosphatase,BALP)高于治疗组(P<0.05)。两组患者Gruen 1、7区的骨密度在术后3、6及12个月较术后1周(基线)均下降(P<0.05);对照组Gruen 7区术后各时间点比较,差异有统计学意义(P<0.05);治疗组各时间点比较,差异无统计学意义(P>0.05)。两组术后3个月Gruen 1、7区比较,差异无统计学意义(P>0.05);术后6个月Gruen 1、7区和术后12个月Gruen 1、7区,治疗组骨密度均明显高于对照组(P<0.05)。两组术后3个月Gruen 1、7区骨密度下降百分比比较,差异无统计学意义(P>0.05)。对照组术后6个月Gruen 1、7区,术后12个月Gruen 1、7区骨密度下降百分比明显高于治疗组(P<0.05)。提示在使用地舒单抗6个月后,即可降低骨密度丢失幅度,并且该效应可达至术后12个月。结论:绝经后骨质疏松性股骨颈骨折患者在THA术后,使用地舒单抗可减少股骨近端假体周围骨密度丢失,有效抑制骨吸收。     

唑来膦酸缓解骨质疏松性椎体骨折经皮椎体成形术后疼痛的临床研究

目的研究唑来膦酸缓解骨质疏松性椎体压缩骨折经皮椎体成形术后残余疼痛的效果。方法回顾性分析自2012-01—2014-01采用经皮椎体成形术治疗的骨质疏松性胸腰椎压缩骨折64例,唑来膦酸组34例,对照组30例术后拒绝使用唑来膦酸。结果 64例均随访至术后12个月。唑来膦酸组术后12个月VAS评分明显低于对照组,差异有统计学意义(t=-1.81,P=0.03)。唑来膦酸组术后12个月VAS评分较术前及术后3 d均有明显改善;对照组术后12个月VAS评分较术前明显改善,但与术后3 d比较有所增加。唑来膦酸组术后12个月腰椎(t=4.71,P0.01)及股骨近端(t=4.34,P0.01)的骨密度较对照组高,差异有统计学意义(P0.05)。结论唑来膦酸对骨质疏松性椎体压缩骨折经皮椎体成形术后疼痛具有明显的缓解作用。     

利塞膦酸钠对非骨水泥型全髓关节置换术后早期股骨假体周围骨密度的影响

目的 探讨利塞膦酸钠对非骨水泥型全髋关节置换术后早期股骨假体周围骨密度的影响及治疗作用,以其为临床提供防止假体周围骨丢失和松动的预防措施和处理方法.方法 2011年3月～2012年5月于本院行非骨水泥型人工全髋关节置换术中符合纳入标准的患者共26例随机分成利塞膦酸钠组与对照组;试验组术后每日口服利塞膦酸钠5 mg+钙剂600 mg,而对照组仅服用钙剂600 mg;分别于术后1周、3、6个月测定股骨近端各感兴趣区(ROI)的骨密度.结果 获得完整病例24例,术后3、6个月各区骨密度均呈持续下降趋势,和对照组相比,术后3个月利塞膦酸钠组股骨假体(ROI1、ROI7)的差异有统计学意义(P＜0.01),其余各测量区骨密度2组相比差异无统计学意义(P＞0.05).与对照组相比,术后6个月利塞膦酸钠组股骨假体(ROI1、ROI7)的差异有统计学意义(P＜0.01),其余各测量区骨密度2组相比差异无统计学意义(P＞0.05).结论 利塞膦酸钠能够有效的减少非骨水泥型全髋关节置换术后假体周围的骨丢失,从而减缓假体松动,延长假体使用寿命.     

唑来膦酸预防全髋关节置换术后早期骨丢失的初步临床研究

目的观察唑来膦酸注射液(密固达)防治全髋关节置换术后假体柄周围骨丢失的近期临床疗效。方法 2012年5月-2012年6月接受单侧全髋关节置换术患者,共20例,随机分为唑来膦酸组(观察组)和对照组。观察组术后1周接受唑来膦酸注射液静脉滴注,5 mg/次,共1次;对照组不接受唑来膦酸注射液治疗。术前、术后1年分别运用双能X骨密度仪测量股骨柄周围骨密度,分析骨量变化情况。结果共入选20例患者,两组各10例,随访1年;术后1年两组股骨假体周围平均骨密度均有所下降,I区和VII区下降显著,观察组IV区骨密度增高趋势。观察组股骨侧骨密度由术前平均1.523±0.325降至1.463±0.376,对照组由平均1.579±0.286降至1.295±0.357。术后3天两组钙、磷水平较术前稍下降,1年后均维持在术前水平。两组术后短期内ALP稍有所下降,与术前水平比较无显著差异;术后1年,对照组ALP恢复术前水平,观察组ALP处于较低水平,与术前及对照组比较具有显著差异。观察组用药后2-3天内有8例患者出现不同程度发热或肌肉酸痛,经服用乙酰氨基酚(泰诺林)缓解。结论唑来膦酸注射液可有效预防全髋关节置换术后早期假体柄周围骨量丢失,具有良好的依从性,但存在流感样副作用,术后1周内难以与手术相关发热相鉴别,故建议手术1周后,待全身情况稳定后使用,出现发热等症状时,给予乙酰氨基酚等消炎止痛类药物可缓解,未见其他不良反应。     

Periprosthetic bone mineral density changes with femoral components of differing design philosophy

We measured the bone mineral density in 22 patients with the cylindrical stemmed cobalt-chrome AML prosthesis (collared) and in 22 patients with the tapered stem titanium CLS prosthesis (collarless). DEXA scanning was undertaken at a mean of 40 months in the AML and 52 months in the CLS group from the time of implant insertion. In both groups the greatest mean loss of BMD was found in Gruen zone 7 and the least change in Gruen zone 5. In all zones the BMD loss was greater in the AML group but only statistically significant in zones 6 (P<0.05) and 7 (P<0.01). Although numerous factors affect BMD changes around cementless implants, this study suggests that less bone loss can be associated with the titanium CLS stem.     

Periprosthetic bone remodelling of two types of uncemented femoral implant with proximal hydroxyapatite coating: a 3-year follow-up study addressing the influence of prosthesis design and preoperative bone density on periprosthetic bone loss

Periprosthetic bone loss is a major cause of concern in patients undergoing total hip arthroplasty (THA). Further studies are required to identify the factors determining the pattern of bone remodelling following THA and obtain improvements in the design and durability of prostheses. In this study, we monitored periprosthetic bone loss around two different types of hydroxyapatite coated femoral implant over a 3-year period to evaluate their design and investigate the relationship with the preoperative bone mineral density (BMD) at the spine, hip and forearm. Sixty patients (35 F, 25 M, mean age 63 years, range 46–75 years) undergoing THA were randomised to either the Anatomic Benoist Girard (ABG) or Mallory-Head (MH) femoral stem. Preoperative dual-energy X-ray absorptiometry (DXA) scans were acquired of the posteroanterior (PA) and lateral lumbar spine, the contralateral hip and the non-dominant forearm. Postoperative DXA scans were performed to measure periprosthetic BMD at 10 days (treated as baseline), 6 weeks, and 3, 6, 12, 24 and 36 months after THA using a standard Gruen zone analysis. Results were expressed as the percentage change from baseline and the data examined for the differences in bone loss between the different Gruen zones, between the ABG and MH stems, and the relationship with preoperative BMD. A total of 50 patients (24 ABG, 26 MH) completed the study. Three months after THA there was a statistically significant BMD decrease in every Gruen zone that varied between 5.6% and 13.8% for the ABG prosthesis and between 3.8% and 8.7% for the MH prosthesis. Subsequently, in most zones BMD reached a plateau or showed a small recovery. However, BMD continued to fall in Gruen zones 1 and 7 in ABG patients and Gruen zone 1 in MH patients. Bone loss was less in every Gruen zone in MH patients compared with ABG with the largest difference (10%, P=0.018) in Gruen zone 7. Highly significant relationships were found between periprosthetic bone loss and preoperative BMD measured at the PA spine (P<0.001), total hip (P=0.004) and total distal radius (P<0.001). This study showed differences between two different designs of hydroxyapatite-coated implant that confirmed that prosthesis design influences periprosthetic bone loss. The study also showed that patients bone density measured at the spine, hip or forearm at the time of operation was a major factor influencing bone loss around the femoral stem.     

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.     

Cemented versus cementless revision femoral stems using morselized allograft--a prospective, randomized study with 5 years follow-up

BACKGROUND: There are only few studies on hip revision using the impaction grafting technique. Furthermore, data on cementless femoral stems as compared to cemented and polished femoral stems are lacking. We wanted to determine whether cementless femoral stems were equally good in preserving bone mineral density around the femoral stem and in functional outcome. METHOD: Consecutively 14 patients needing hip revisions for aseptic loosening in the stem with bone stock deficiency Paparowsky grade II were randomized into two groups intraoperatively. Morselized fresh-frozen bone allografts were impacted in both groups. The cemented group received polished Landos Fjord-CrCo stems and the uncemented group received the hydroxyapatite-coated Landos Corail-Titan stems. The dual energy X-ray absorptiometry was used to measure bone mineral density around the femoral stem according to Gruen zones. Function was measured by Merle d'Aubigné score. Patients were controlled at 0.5, 3, 6, 9, 12, 18, 24, 36 and 60 months postoperatively. RESULTS: There was no statistical difference between the BMD loss in the cemented vs. the uncemented group. The BMD loss was between 0-10 % in distal Gruen zones and was between 10-20 % in proximal Gruen zones. Functional scores were similar and reached a plateau of 16 in the Merle d'Aubigné score after 6 months. CONCLUSIONS: Cemented technique in hip revisions using morselized bone allograft is as good as uncemented technique in preserving BMD measured by the DEXA method and restoring function in a 5 years follow-up.     

Continuous bone loss around a tapered uncemented femoral stem: a long-term evaluation with DEXA

Background Periprosthetic bone loss is a well-docu-mented phenomenon after uncemented total hip arthroplasty (THA); however, little is known about how bone mineral density (BMD) changes after 2 years.

Patients and methods 14 patients with hip arthrosis (group A) were operated with a proximally porous- and hydroxyapatite-coated stem and followed for 10 years with DEXA, radiographs and Harris hip score (HHS). Another group of 14 patients (group B) was evaluated at 6 and 14 years using the same prosthesis and protocol.

Results No stem was revised and all stems were well-Fixed. At final follow-up, HHS was 97 points in group A after 10 years and 94 points in group B after 14 years. Bone mineral changes in group A were greatest in Gruen zones 1 and 7, where the losses were 31% and 26%, respectively, after 2 years on the operated side. The decrease in BMD continued after 2 years and in Gruen zone 7 it was faster than the rate of bone loss on the control side. In group B, the annual change in BMD on the operated side was not significantly different from the bone loss in group A.

Interpretation Up to 14 years after implantation of a tapered uncemented stem, the BMD in the calcar region continues to decrease faster than would be expected from normal ageing.     

Bone loss around failed femoral implant measured by dual-energy X-ray absorptiometry

Periprosthetic bone mineral density (BMD) and its changes after primary total hip arthroplasty (THA) have been studied extensively, but quantitative data on BMD around loosened prostheses are still lacking. In this study, using dual-energy X-ray absorptiometry (DXA), we determined periprosthetic BMD in 19 patients with failed primary THA. There was a decrease in BMD (8.8%–25.5%) in every Gruen zone as compared with the patient's non-operated (control) side. Although the bone loss was most significant in the proximal femur, as in primary THA, the pattern of bone loss around the failed THA differred from the typical remodeling seen after successful THA. We suggest that quantitation of bone mass around the failed femoral stem is possible. Remarkable generalized bone loss around the stem is associated with a loosened prosthesis. Received: November 12, 1999 / Accepted: December 24, 1999     

Continuous bone loss around a tapered uncemented femoral stem: A long-term evaluation with DEXA

Background?Periprosthetic bone loss is a well-docu-mented phenomenon after uncemented total hip arthroplasty (THA); however, little is known about how bone mineral density (BMD) changes after 2 years.

Patients and methods?14 patients with hip arthrosis (group A) were operated with a proximally porous- and hydroxyapatite-coated stem and followed for 10 years with DEXA, radiographs and Harris hip score (HHS). Another group of 14 patients (group B) was evaluated at 6 and 14 years using the same prosthesis and protocol.

Results?No stem was revised and all stems were well-Fixed. At final follow-up, HHS was 97 points in group A after 10 years and 94 points in group B after 14 years. Bone mineral changes in group A were greatest in Gruen zones 1 and 7, where the losses were 31% and 26%, respectively, after 2 years on the operated side. The decrease in BMD continued after 2 years and in Gruen zone 7 it was faster than the rate of bone loss on the control side. In group B, the annual change in BMD on the operated side was not significantly different from the bone loss in group A.

Interpretation?Up to 14 years after implantation of a tapered uncemented stem, the BMD in the calcar region continues to decrease faster than would be expected from normal ageing.     

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.