Total Hip Replacement in Inflammatory Hip Disease using the Charnley Prosthesis

The Charnley low-friction arthroplasty was performed on 73 hips in 55 patients with inflammatory joint disease, usually for intolerable pain. Sixty-five of these operations were reviewed at a special clinic or by postal questionnaire; 57 hips were painfree or gave rise to only occasional discomfort, in 58 there was an increased range of movement, and in 46 of the 59 hips assessed clinically, the results were excellent or good. The most serious complication was deep infection, which occurred in 7 operations.     

Friction in Total Hip Joint Prosthesis Measured In Vivo during Walking

Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al₂O₃ ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was calculated in 3D throughout the whole gait cycle, and average values of the friction-induced power dissipation in the joint were determined. On average, peak contact forces of 248% of the bodyweight and peak friction moments of 0.26% bodyweight times meter were determined. However, contact forces and friction moments varied greatly between individuals. The friction moment increased during the extension phase of the joint. The average coefficient of friction also increased during this period, from 0.04 (0.03 to 0.06) at contralateral toe off to 0.06 (0.04 to 0.08) at contralateral heel strike. During the flexion phase, the coefficient of friction increased further to 0.14 (0.09 to 0.23) at toe off. The average friction-induced power throughout the whole gait cycle was 2.3 W (1.4 W to 3.8 W). Although more parameters than only the synovia determine the friction, the wide ranges of friction coefficients and power dissipation indicate that the lubricating properties of synovia are individually very different. However, such differences may also exist in natural joints and may influence the progression of arthrosis. Furthermore, subjects with very high power dissipation may be at risk of thermally induced implant loosening. The large increase of the friction coefficient during each step could be caused by the synovia being squeezed out under load.     

人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床分析

目的:探讨人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床疗效。方法:对2009年7月至2012年7月入住我院的60例成人髋关节发育不良并骨性关节炎患者行人工全髋关节置换术治疗。分析治疗优良率、手术前后不同Crowe分型Harris评分、手术前后行走及疼痛情况、手术前后生活质量。结果:1根据Harris评分,本组治疗优良率91.67%(55/60);2术后各Crowe分型患者Harris评分均显著高于术前,差异均具有统计学意义(P<0.05);3本组术前自行行走及辅助行走例数分别为23及37例,术后分别为39例及21例;术前疼痛情况:无、轻、中及重度疼痛例数分别为1例、6例、22例及31例,术后分别为18例、28例、12及2例,手术前后行走情况及疼痛情况差异均具有统计学意义(P<0.05);4根据SF-36生活质量评价标准,术后生活质量评分为(142.16±10.32)分,显著高于术前(115.24±7.34)分,差异具有统计学意义(P<0.05)。结论:人工全髋关节置换治疗成人髋关节发育不良并骨性关节炎的临床疗效显著,术后患者髋关节功能及生活质量明显改善,应在临床上加以推广。     

Postoperative Changes in In Vivo Measured Friction in Total Hip Joint Prosthesis during Walking

Loosening of the artificial cup and inlay is the most common reasons for total hip replacement failures. Polyethylene wear and aseptic loosening are frequent reasons. Furthermore, over the past few decades, the population of patients receiving total hip replacements has become younger and more active. Hence, a higher level of activity may include an increased risk of implant loosening as a result of friction-induced wear. In this study, an instrumented hip implant was used to measure the contact forces and friction moments in vivo during walking. Subsequently, the three-dimensional coefficient of friction in vivo was calculated over the whole gait cycle. Measurements were collected from ten subjects at several time points between three and twelve months postoperative. No significant change in the average resultant contact force was observed between three and twelve months postoperative. In contrast, a significant decrease of up to 47% was observed in the friction moment. The coefficient of friction also decreased over postoperative time on average. These changes may be caused by ‘running-in’ effects of the gliding components or by the improved lubricating properties of the synovia. Because the walking velocity and contact forces were found to be nearly constant during the observed period, the decrease in friction moment suggests an increase in fluid viscosity. The peak values of the contact force individually varied by 32%-44%. The friction moment individually differed much more, by 110%-129% at three and up to 451% at twelve months postoperative. The maximum coefficient of friction showed the highest individual variability, about 100% at three and up to 914% at twelve months after surgery. These individual variations in the friction parameters were most likely due to different ‘running-in’ effects that were influenced by the individual activity levels and synovia properties.     

Pain Threshold Analysis in Patients with Osteoarthrosis of Hip

The pain threshold was measured in patients with osteoarthrosis of the hip. The pain threshold was significantly lower in patients who required surgery than in controls. After successful surgery the threshold rose to normal levels. In patients with few or no symptoms from their osteoarthritic hips the pain threshold was high. Insensitivity to pain does not predispose towards osteoarthrosis of the hip. Indeed, the severity of symptoms can be directly related to an increased sensitivity to pain in osteoarthritic subjects.     

Fenoprofen in Treatment of Osteoarthrosis of Hip and Knee

Two studies on 41 patients with osteoarthrosis of the hip or knee have shown fenoprofen—a compound with analgesic and anti-inflammatory properties—to be an effective addition to the drug treatment of these conditions. It was found to be superior to paracetamol but no statistically significant difference was shown in a comparison with phenylbutazone.     

大直径陶瓷假体用于全髋关节置换术的稳定性和安全性

目的:探讨大直径陶瓷-陶瓷假体对髋关节置换患者术后假体磨损,稳定性和髋关节功能的影响。方法:选取我院2010年1月-2014年1月间采用大直径陶瓷-陶瓷假体行关全髋置换的股骨头坏死患者46例作为研究组。另选40例采用标准金属-聚乙烯假体手术患者作为对照组。观察并比较两组患者假体磨损情况、髋关节稳定性和功能评分。结果:研究组患者术后无一例脱位,发生假体松动1例,Harris评分为(82.04±1.92)分;对照组术后发生假体脱位4例,松动4例,Harris评分为(81.37±1.27)分;研究组假体稳定性和磨损程度优于对照组,差异具有统计学意义(P0.05),但两组髋关节功能评分无显著差异(P0.05)。发生假体松动的患者术后血沉、IL-1和IL-6浓度均高于正常值,差异具有统计学意义(P0.05)。结论:与标准假体相比,大直径陶瓷-陶瓷假体稳定性好,磨损率低,是全髋置换手术的良好假体。     

Total Hip Replacement for the Treatment of End Stage Arthritis of the Hip: A Systematic Review and Meta-Analysis

Background

Evolvements in the design, fixation methods, size, and bearing surface of implants for total hip replacement (THR) have led to a variety of options for healthcare professionals to consider. The need to determine the most optimal combinations of THR implant is warranted. This systematic review evaluated the clinical effectiveness of different types of THR used for the treatment of end stage arthritis of the hip.

Methods

A comprehensive literature search was undertaken in major health databases. Randomised controlled trials (RCTs) and systematic reviews published from 2008 onwards comparing different types of primary THR in patients with end stage arthritis of the hip were included.

Results

Fourteen RCTs and five systematic reviews were included. Patients experienced significant post-THR improvements in Harris Hip scores, but this did not differ between impact types. There was a reduced risk of implant dislocation after receiving a larger femoral head size (36 mm vs. 28 mm; RR = 0.17, 95% CI: 0.04, 0.78) or cemented cup (vs. cementless cup; pooled odds ratio: 0.34, 95% CI: 0.13, 0.89). Recipients of cross-linked vs. conventional polyethylene cup liners experienced reduced femoral head penetration and revision. There was no impact of femoral stem fixation and cup shell design on implant survival rates. Evidence on mortality and complications (aseptic loosening, femoral fracture) was inconclusive.

Conclusions

The majority of evidence was inconclusive due to poor reporting, missing data, or uncertainty in treatment estimates. The findings warrant cautious interpretation given the risk of bias (blinding, attrition), methodological limitations (small sample size, low event counts, short follow-up), and poor reporting. Long-term pragmatic RCTs are needed to allow for more definitive conclusions. Authors are encouraged to specify the minimal clinically important difference and power calculation for their primary outcome(s) as well CONSORT, PRISMA and STROBE guidelines to ensure better reporting and more reliable production and assessment of evidence.     

Concentration of Wear Products in Hair,Blood, and Urine after Total Hip Replacement

Raised levels of cobalt and chromium are found in the blood and urine of patients with metallic total hip replacements. When one of the hip components is made of polyethylene much less metal seems to be released from the joint. The long-term effects of the accumulation of chromium in the body need to be studied further.     

Cost-Effectiveness of Five Commonly Used Prosthesis Brands for Total Knee Replacement in the UK: A Study Using the NJR Dataset

Background

There is a lack of evidence on the effectiveness or cost-effectiveness of alternative brands of prosthesis for total knee replacement (TKR). We compared patient-reported outcomes, revision rates, and costs, and estimated the relative cost-effectiveness of five frequently used cemented brands of unconstrained prostheses with fixed bearings (PFC Sigma, AGC Biomet, Nexgen, Genesis 2, and Triathlon).

Methods

We used data from three national databases for patients who had a TKR between 2003 and 2012, to estimate the effect of prosthesis brand on post-operative quality of life (QOL) (EQ-5D-3L) in 53 126 patients at six months. We compared TKR revision rates by brand over 10 years for 239 945 patients. We used a fully probabilistic Markov model to estimate lifetime costs and quality-adjusted life years (QALYs), incremental cost effectiveness ratios (ICERs), and the probability that each prosthesis brand is the most cost effective at alternative thresholds of willingness-to-pay for a QALY gain.

Findings

Revision rates were lowest with the Nexgen and PFC Sigma (2.5% after 10 years in 70-year-old women). Average lifetime costs were lowest with the AGC Biomet (£9 538); mean post-operative QOL was highest with the Nexgen, which was the most cost-effective brand across all patient subgroups. For example, for 70-year-old men and women, the ICERs for the Nexgen compared to the AGC Biomet were £2 300 per QALY. At realistic cost per QALY thresholds (£10 000 to £30 000), the probabilities that the Nexgen is the most cost-effective brand are about 98%. These results were robust to alternative modelling assumptions.

Conclusions

AGC Biomet prostheses are the least costly cemented unconstrained fixed brand for TKR but Nexgen prostheses lead to improved patient outcomes, at low additional cost. These results suggest that Nexgen should be considered as a first choice prosthesis for patients with osteoarthritis who require a TKR.     

Orudis in Management of Rheumatoid Arthritis and Osteoarthrosis of the Hip: Comparison with Indomethacin

In double-blind cross-over studies in 46 patients with rheumatoid arthritis and in 42 patients with osteoarthrosis of the hip, Orudis—a new non-steroidal anti-inflammatory agent—has been shown to be well tolerated and to have comparable therapeutic efficacy with indomethacin when given in equal dosage. Side effects were less severe with Orudis. The results suggest that Orudis will prove valuable in the clinical management of rheumatic diseases.     

髋关节假体脱位分析软件的设计与开发

目的研发了髋关节假体脱位分析软件。软件基于ADAMS/VIEW软件进行二次开发,能够可视化的构建三维参数化的髋关节假体模型,模型能够模拟假体的六种运动。应用此软件可以为病人更好的选择和植入假体,评估各种髋关节假体的安全活动范围,用来设计新的关节假体。     

Peri-implant Bone Remodeling after Total Hip Replacement Combined with Systemic Alendronate Treatment: A Finite Element Analysis

In order to decrease the peri-implant bone loss during the life-time of the implant, oral use of anti-osteoporosis drugs (like bisphosphonates) has been suggested.

In this study, bone remodeling parameters identified from clinical trials of alendronate were used to simulate the effect of those drugs used after total hip arthroplasty on the peri-implant bone density. Results of the simulation show that the oral administrated drugs increase bone density around the implant and decreases, at the same time, the micromovements between the implant and the surrounding bone tissue.

Incorporation of drug effect in numerical studies of bone remodeling is a promising tool especially to predetermine safe bisphosphonate doses that could be used with orthopedic implants.     

Association between Apoptotis and CD4+/CD8+ T-Lymphocyte Ratio in Aseptic Loosening after Total Hip Replacement

Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. While the osteolytic cascade initiated by cytokine release from macrophages has been studied extensively, the involvement of T-lymphocytes in this context is controversial and has been addressed by only a few authors. In a former study we detected that the quantity of T-lymphocytes may be influenced by apoptosis in patients with aseptic loosening. In this study we intended to find out more details about the apoptosis-induced shifting of the T-cell number. We focused our interest on the CD4⁺ and CD8⁺ T-cells and their relative ratio. Caspase-3 cleaved was evaluated immunohistochemically to detect apoptotic T-cells in capsules and interface membranes from patients with aseptic hip implant loosening and a varying degree of caspase-3 cleaved expression in CD4⁺ and CD8⁺ T-lymphocytes was detected. Moreover, a relationship between the intensity of the apoptotic reactions and the radiological extent of osteolysis was observed. The number of CD4⁺ cells was decreased in the presence of strong apoptotic reactions, respectively extensive osteolysis, while CD8⁺ cells were affected to a much lower degree. Thus, the CD4⁺/CD8⁺ ratio changed from 1.0 in cases with only small areas of periprosthetic osteolysis and minimally intense apoptosis to 0.33 in cases with large areas of osteolysis. This may suggest a causal relationship between the apoptosis-induced shift in the CD4⁺/CD8⁺ ratio and the osteolysis respectively aseptic loosening. It is possible that these findings may lead to a new understanding of particle-induced osteolysis.     

Age Related Macular Degeneration and Total Hip Replacement Due to Osteoarthritis or Fracture: Melbourne Collaborative Cohort Study

Osteoarthritis is the leading cause of total hip replacement, accounting for more than 80% of all total hip replacements. Emerging evidence suggests that osteoarthritis has a chronic inflammatory component to its pathogenesis similar to age-related macular degeneration. We evaluated the association between age-related macular degeneration and total hip replacement as proxy for severe osteoarthritis or fractured neck of femur in the Melbourne Collaborative Cohort Study. 20,744 participants had complete data on both age-related macular degeneration assessed from colour fundus photographs taken during 2003–2007 and total hip replacement. Total hip replacements due to hip osteoarthritis and fractured neck of femur during 2001–2011 were identified by linking the cohort records to the Australian Orthopedic Association National Joint Replacement Registry. Logistic regression was used to examine the association between age-related macular degeneration and risk of total hip replacement due to osteoarthritis and fracture separately, adjusted for confounders. There were 791 cases of total hip replacement for osteoarthritis and 102 cases of total hip replacement due to fractured neck of femur. After adjustment for age, sex, body mass index, smoking, and grouped country of birth, intermediate age-related macular degeneration was directly associated with total hip replacement for osteoarthritis (odds ratio 1.22, 95% CI 1.00–1.49). Late age-related macular degeneration was directly associated with total hip replacement due to fractured neck of femur (odds ratio 5.21, 95% CI2.25–12.02). The association between intermediate age-related macular degeneration and an increased 10-year incidence of total hip replacement due to osteoarthritis suggests the possibility of similar inflammatory processes underlying both chronic diseases. The association of late age-related macular degeneration with an increased 10-year incidence of total hip replacement due to fractured neck of femur may be due to an increased prevalence of fractures in those with poor central vision associated with the late complications of age-related macular degeneration.     

Bone Allograft in Revision Total Knee Replacement

Revision total knee replacement (TKR) is often associated with the necessity to reconstruct a certain amount of bone loss. In a retrospective study we reviewed the records of 137 patients who had undergone revision TKR in our department between 1990 and 1996, due to loosening or inflection. Bone allografts were used in 91 patients (67%) to accomplish stable, new prostheses. Three types of bone loss were identified in this group: Type I - minor, Type II – moderate, and Type III – large bone defects, located on either side of the knee joint – A, or both sides – B.The treatment results of these 91 patients, according to the type of bone loss, are presented, showing good functional outcome when utilizing bone allografts in revision TKR. However, careful preoperative planning, identification of bone loss type, and a well-equipped bone bank are mandatory to the success of the operation.