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.     

Periacetabular Bone Mineral Density Changes After Resurfacing Hip Arthroplasty Versus Conventional Total Hip Arthroplasty. A Randomized Controlled DEXA Study

A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt–chromium cup (n = 38) or a THA with a threaded titanium cup and polyethylene-metal-inlay insert (n = 33). The BMD in five separate periacetabular regions of interest (ROI) was prospectively quantified preoperative until 24 months. We conclude that, in contrast to our hypothesis, periacetabular BMD was better preserved after RHA than after placement of a conventional THA. Long term follow-up studies are necessary to see whether this benefit in bone preservation sustains over longer time periods and whether it is turned into clinical benefits at future revision surgery.     

Femoral revision in hip resurfacing compared with large-bearing metal-on-metal hip arthroplasty

It has been suggested that revision of the femoral component of hip resurfacing after femoral failure would be straightforward and have an outcome comparable to primary total hip arthroplasty (THA). We have compared the outcome of femoral side-only revision resurfacings to the results of primary modular large-bearing metal-on-metal THA. Fourteen consecutive patients underwent revision surgery of the failed femoral component, to a cemented tapered stem (CPT, Zimmer, Warsaw, Indiana) with a large modular metal head (Smith and Nephew Orthopaedics Ltd, Memphis, Tennessee, or Adept, Finsbury Orthopaedics, Surrey, England). The acetabular component was found to be well fixed, well orientated, and was left in situ. The 14 matched patients in the primary THA group received the same components. At a mean follow-up of 49 months (range, 30-60 months), clinical outcome measured using the Oxford and Harris Hip Scores showed no significant difference (P = .11, P = .45, respectively). Operative time and blood loss were comparable for both groups. We conclude that revision of the failed femoral resurfacing component gives excellent results.     

The effects of technique changes on aseptic loosening of the femoral component in hip resurfacing. Results of 600 Conserve Plus with a 3 to 9 year follow-up

The purpose of the present study was to determine the effectiveness of modifications in the surgical technique on loosening of the femoral component in the first 600 consecutive Conserve Plus metal-on-metal hybrid resurfacings (Wright Medical Technologies, Arlington, Tenn). These modifications were gradually introduced over time, but all the changes were implemented after the first 300 hips. The average age of the patients was 48.9 years, and 74% were male. The average follow-up was 70.5 months for the first 300 hips and 42.4 months for the second 300, and there was a significant improvement (P = .016) of the second 300 hips over the first 300 in a time-dependent analysis using as an end point the time to appearance of a radiolucency, suggesting potential femoral component loosening. None of the components with cemented stems showed femoral radiolucencies or were revised for aseptic loosening. Adding fixation holes in the dome and chamfered areas and cleansing and drying using a suction tip in the dome hole were significantly related to the improvement of the results. Positioning the femoral component in a more valgus position did not show any effect as an independent variable.     

Sequential changes in periprosthetic bone mineral density following total hip arthroplasty: a 3-year follow-up

 We sequentially measured the periprosthetic bone mineral density (BMD) of the femur after cementless total hip arthroplasty, using dual-energy X-ray absorptiometry, over a 3-year period. The periprosthetic bone was divided into three regions (proximo-medial, middle, and distal to the prosthetic stem). After the insertion of a fully porous coated stem in 21 patients, the BMD was measured within 3 weeks, and 6, 12, 24, and 36 months after surgery. At 6 months, all zones showed a decrease in BMD relative to the BMD within 3 weeks, but subsequently the BMD was unchanged. The lower the BMD within 3 weeks of surgery, or the lower the body weight, the higher the percent loss of BMD at 6 months. Received: September 9, 2002 / Accepted: December 12, 2002 RID="*" ID="*" Offprint requests to: H. Ohta     

Five-year results of metal-on-metal resurfacing arthroplasty in Asian patients

Clinical results of 50 metal-on-metal resurfacing arthroplasties in 45 Japanese patients were evaluated to a minimum follow-up of 5 years. The predominant diagnosis was developmental dysplasia or dislocation of the hip (70%). One patient died of an unrelated cause and another was lost to follow-up. Two hips received revision surgery, including 1 femoral neck fracture and 1 septic loosening. In the remaining 46 hips, 1 hip showed femoral component loosening. Clinical scores of the 46 hips were satisfactory at the final follow-up. The survival rate at 5 years was 96% when failure was attributed to revision for any reason. Metal-on-metal resurfacing arthroplasty in Japanese patients, who have a different distribution of hip diseases from European and American patients, showed similarly promising early clinical results.     

Gait symmetry: a comparison of hip resurfacing and jumbo head total hip arthroplasty patients

Proponents of large femoral head total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) have touted the potential for restoration of more normal hip kinematics. This study examined 20 patients (10 THA and 10 HRA patients) approximately 18 months after surgery. Subjects were evaluated at a self-selected pace, while bilateral spatial-temporal gait variables, hip flexion/extension kinematics, and ground reaction forces were collected. For both groups, swing time was increased on the surgical side, whereas peak hip flexion, peak extension, and flexion at heel strike were decreased. Peak hip extension and peak vertical ground reaction forces were decreased in THA subjects compared with HRA subjects. After a large-diameter THA or HRA, subjects do not display symmetric gait approximately 18 months postoperatively. Total hip arthroplasty subjects demonstrated restricted hip extension and reduced limb loading when compared with HRA subjects.     

金属对金属全髋关节表面置换治疗髋关节色素沉着绒毛结节性滑膜炎早期临床效果观察

目的探讨金属对金属全髋关节表面置换术治疗髋关节色素沉着绒毛结节性滑膜炎(PVNS)的可行性及早期临床效果。方法对7例经影像学检查及病理检查确诊的PVNS实施了滑膜切除+全髋关节表面置换术,术后康复锻炼。手术前后行Harris髋关节功能评分。结果7例均获随访,时间12～20(14.6±2.4)个月。患者假体位置良好,无松动、股骨颈骨折及明显骨溶解等并发症,关节活动度90°～130°,可从事日常生活,未出现复发症状。Harris髋关节功能评分由术前(45.2±7.8)分改善至术后(95.8±2.6)分。结论全髋关节表面置换术结合滑膜切除术早期能有效改善髋关节PVNS患者的临床症状、提高生活质量。     

Proximal femoral bone mineral density after resurfacing total hip arthroplasty and after standard stem-type cementless total hip arthroplasty, both having similar neck preservation and the same articulation type

To examine whether the Freeman cementless total hip arthroplasty (THA), with femoral neck preservation and a large metal head, can prevent stress shielding in a manner similar to resurfacing THA, we compared femoral bone mineral density (BMD) change in 10 resurfacing THA patients (group A) and 16 cementless THA patients (group B). Six and twelve months postoperatively, the mean BMD ratio in zone 1 was significantly higher in group A (97% +/- 10%, 95% +/- 11%) than in group B (79% +/- 15%, 77% +/- 20%); at 12 months, the mean BMD ratio in zone 7 was significantly higher in group A (104% +/- 15%) than in group B (84% +/- 21%). The cementless THA might not be a substitute for the resurfacing THA with respect to prevention of proximal femoral bone loss at the femoral neck, although it may prevent some major complications after resurfacing THA such as neck fracture and avascular necrosis of the femoral head.     

Cementless hemispheric acetabular component for acetabular revision arthroplasty: a 5- to 19-year follow-up study

This study evaluated the 5- to 19-year clinical and radiographic results of cementless acetabular revision. Between 1986 and 1998, 130 hips (125 patients) underwent cementless acetabular revisions. Ten patients were lost to follow-up; 6 patients died. One hundred nine patients (114 hips) were reviewed at a mean follow-up of 8.8 years. The mean Harris hip score improved from 62.1 to 90.7 at final follow-up. Two hips underwent repeat revision. Twenty-two hips developed cavitary osteolysis. Kaplan-Meier survivorship at 121 months was 98.2% with repeat revision for any reason as the end point and 89.5% with repeat revision or radiographic loosening as the end point. Cementless acetabular revision provides favorable clinical and radiographic results, and the initial disease and age may adversely affect the outcomes.     

Metal sensitivity as a cause of groin pain in metal-on-metal hip resurfacing

We describe 4 patients pooled from our patient populations who presented with groin pain at different periods postoperatively after implantation of a metal-on-metal hip resurfacing. Each patient underwent exploratory surgery after radiographic imaging, hematologic testing, and microbiological assessment of joint aspirations failed to explain their symptoms. Samples of periprosthetic tissues revealed extensive amounts of lymphocytic infiltrates that were suggestive of an immunologic reaction. The patients obtained complete resolution of symptoms subsequent to revision surgery. The incidence of implant failures resulting from metal sensitivity is unknown owing to the difficulty in making a confirmed diagnosis. The possibility that this is the source of groin pain should be considered when other reasons for symptoms of pain and/or joint effusion in hips with metal-on-metal resurfacing arthroplasties have been discounted.     

Distribution of chromium and cobalt ions in various blood fractions after resurfacing hip arthroplasty

The most appropriate blood fraction for the measurement of metal ions in patients with metal-on-metal implants is controversial. We compared chromium (Cr) and cobalt (Co) ion levels in 29 patients after unilateral hip resurfacing with a size 54-mm femoral Birmingham Hip Resurfacing Prosthesis (Smith and Nephew, London, UK). All had well-functioning arthroplasties between 5 and 59 months after implantation. Ion levels were measured in serum, plasma, red cells, and whole blood in each patient. Our results indicate that only very minor amounts of Cr and Co are associated with red blood cells, with most being associated with serum/plasma. Previous studies using corrosion to produce the ion load have showed a predominance of Cr in the red blood cells. They have also shown that the cellular uptake of Cr is an indicator of its valence. This difference in distribution with our results is indirect evidence that the Cr released from wear of this implant is probably in the more benign trivalent form. It also suggests that most of the metal loss from a normally wearing bearing may be from wear rather than corrosion. If blood is to be used to assess rates of wear and systemic ion levels, then serum gives a better reflection of the true levels than red blood cells.     

Hip squeaking: a 10-year follow-up study

The aim of the study was to analyze the incidence of squeaking with ceramic-on-ceramic total hip arthroplasty (THA) after 10 years of follow-up and the potential complications that could occur related to this phenomenon. One hundred THAs implanted between November 1999 and December 2000 were evaluated. Incidence of squeaking was investigated clinically with a questionnaire. Implant positioning was analyzed on x-rays and computer tomography. Of the 100 THAs, 5 patients presented with squeaking. All of them were active, sporty, and heavy men. Functional scores were comparable with nonsqueaking patients. There was no malpositioning on the x-ray analysis, no wear, and no loosening. We could not demonstrate any relation between squeaking and ceramic fracture. Squeaking noise appeared at a mean of 66 months postsurgery. It appears to be an isolated phenomenon without any consequences at 10-year follow-up.     

Birmingham hip resurfacing versus cementless total hip arthroplasty in patients 55 years or younger: A minimum five-year follow-up

Objective

The optimal reconstructive method for advanced degenerative hip disease in young adults is a topic of ongoing discussion. The purpose of this study is to report the largest single institution experience from the United States on the outcomes of Birmingham hip resurfacing (BHR) vs. cementless total hip arthroplasty (THA) in patients 55 years or younger at a minimum follow-up of five years. Currently, BHR is the only FDA-approved hip resurfacing implant available in the US.

Thermal damage potential during hip resurfacing in osteonecrosis of the femoral head: An experimental study

Hip resurfacing arthroplasty has become an attractive treatment option for young, active patients with femoral head necrosis. However, little information is available about the potential thermal damage to the remaining femoral head when a cemented component is used. We used an experimental model to measure the temperature profile at the cement–bone interface during hip resurfacing. We compared four simulated lesion sizes—15, 25, 33, and 50%—of the femoral head, and a control group with no cystic lesion. Temperatures were measured with the specimens in a 37°C saline bath or with copious pulsed lavage. With specimens tested in the bath, peak temperatures were higher, and durations of temperatures above 50°C were longer, in femoral heads with necrotic lesions (88.8 ± 7.5°C; 17.6 ± 1.1 min for a 15% lesion; 96.2 ± 7.2°C; 22.86 ± 1.3 min for a 25% lesion; 99.7 © 200 ± 9.4°C; 28.6 ± 2.0 min for a 33% lesion; and 97.2 ± 4.2°C; 35.6 ± 2.4 min for a 50% lesion) than those in the control group (65.8 ± 4.9°C; 10.0 ± 1.3 min). The larger the cement‐filled cysts, the longer the temperatures remained above 50°C. Although copious lavage reduced the temperature profile in each group, the temperatures remained above 50°C for 7 to 17 min in specimens with necrotic cysts. The measured temperatures during surface replacement are sufficiently high in magnitude and long in duration to cause thermal damage to the remaining bone in femoral heads with preexisting necrotic lesions. Hip resurfacing for femoral head necrosis should be performed with caution. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1206–1209, 2008     

Computer-assisted vs conventional mechanical jig technique in hip resurfacing arthroplasty

To compare the effectiveness of computer-assisted surgery (CAS) and mechanical jig technique in hip resurfacing arthroplasty, we reviewed 176 hip resurfacing arthroplasty performed in 158 patients. The initial 131 hips were resurfaced using the conventional mechanical jig technique, and the remaining 45 hips with the CAS technique. The demographic data of the patients were similar for both techniques. Follow-up radiographs taken 2 months after the surgery showed patients in the CAS technique having a significantly better alignment of the femoral component on the frontal and sagittal planes. There was no difference in the risk of implant notching on the femoral neck for both techniques. The implant sizes were similar for both techniques; thus, the amount of bone stock preserved was not technique specific.     

Uncemented total ankle arthroplasty in post-traumatic osteoarthritis: 3- to 7-year follow-up

Ankle replacement in post-traumatic arthritis is a challenging procedure, and adequate data are lacking about its results, as most studies are mainly focused on the results of ankle arthroplasty in primary osteoarthritis and rheumatoid arthritis. We present the results of 7 ankle replacements in posttraumatic arthritis with an uncemented total ankle arthroplasty at an average follow-up of 5.1 years (range, 3–7). One ankle had been revised and one ankle showed an unsatisfactory result (with radiographic signs of loosening of the talar component). The average functional score of the 6 surviving prostheses was 68.3 according to Kofoed and 70.8 according to AOFAS. Range of motion averaged 24.1° at follow-up. No infections nor collapse of the talus occurred. No ankles showed areas of periprosthetic osteolysis. Periarticular calcifications were a common finding (3 patients) but not evidently connected to the clinical result. Radiographic signs of progressive degeneration of the neighboring joints were present in three patients at the talonavicular joint and in one patient at the talocalcaneal joint. Ankle arthroplasty with new generation prostheses is a promising procedure but results are still worse than those of replacement of the other major joints of the lower limb. Replacement of the post-traumatic ankle presents particular difficulties and studies should evaluate the results separately from ankles affected by primary osteoarthritis and rheumatoid arthritis.     

全髋关节表面置换治疗成人先天性髋关节发育不良与近期疗效

[目的]探讨全髋关节表面置换术治疗成人髋关节发育不良继发骨关节炎的疗效、安全性和有效性。[方法]2005年5~6月,对12例成人髋关节发育不良继发骨关节炎患者13个髋关节进行全髋关节表面置换术。男性4例,女性8例;年龄30~59岁,平均47岁,所有患者均为半脱位型。髋臼侧采用真臼位置重建,为非骨水泥固定,股骨头假体采用骨水泥固定。[结果]手术时间平均110 m in,术中失血平均387 m l,术后引流量平均200 m l,肢体延长平均9 mm(术前短缩平均14 mm)。所有患者切口均一期愈合,无感染、股骨颈骨折、脱位、松动、神经血管损伤等并发症。全部随访12~13个月,临床效果满意,平均髋关节活动度屈曲由106.7°增加到120°,外展由25.8°增加到46.4°,外旋由20.8°增加到45°,内旋由3.3°增加到28.6°,Harris评分由术前的平均42分增加到术后的平均96分。X线片显示关节假体位置正常,人工髋臼平均外展角为39°,股骨头中心柄与股骨干夹角平均141°,髋关节旋转中心位置平均下移9 mm,内移11.5 mm。宿主骨对臼杯的平均覆盖率为89.5%,宿主骨与假体之间未见透亮线。[结论]全髋关节表面置换术治疗半脱位型的成人髋关节发育不良继发骨关节炎患者具有良好的近期疗效和应用前景,其远期疗效及其他类型髋关节发育不良患者的应用还需进一步研究。     

Serum osteocalcin in relation to calcaneal bone mineral density in elderly men and women: a 5-year follow-up

A 5-year follow-up study investigated serum concentrations of total (tOC) and intact (iOC) osteocalcin in relation to calcaneal bone mineral density (BMD). The study comprised two cohorts, 75- and 80-year-olds, both resident in the city of Jyv?skyl?, Finland. Baseline OC and BMD were obtained for 161 men and 233 women, of whom 83 men and 189 women participated in follow-up bone measurements. The mean concentration of tOC increased from 9.6 ± 4.3 to 13.2 ± 8.5 μg/l (P = 0.001) in men and from 11.2 ± 4.9 to 14.0 ± 6.1 μg/l (P < 0.001) in women, whereas mean iOC decreased from 6.4 ± 3.0 to 5.9 ± 3.0 μg/l (P = 0.273) and from 7.7 ± 3.7 to 6.9 ± 3.4 μg/l (P = 0.021) in men and women, respectively. TOC and iOC levels correlated inversely with BMD and change in BMD in both sexes (r ranged from −0.223 to −0.422 and P = 0.048 ≤ 0.001). When we divided the baseline tOC and iOC values into four quartiles, the decrease in BMD was significantly greater in the third tOC quartiles in women and in the fourth tOC and iOC quartiles in men when compared with the lower quartiles. During the 5-year period, 19 men and 59 women sustained at least one fracture. These individuals with fractures had significantly higher iOC values and tended to have higher tOC values compared with the nonfracture group at baseline (P = 0.038 and 0.087, respectively). Our results indicate that baseline serum tOC and iOC were associated with bone loss and predicted fracture in the two cohorts of independently living elderly men and women. Received: December 16, 2000 / Accepted: July 23, 2001