Survival of primary total hip arthroplasty in rheumatoid arthritis patients

Contemporary outcomes of primary total hip arthroplasty in patients with inflammatory arthritis

Aims

Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis.

Methods

We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).

Results

The ten-year cumulative incidence of any revision was 3%, and was highest in psoriatic arthritis patients (16%). The most common indications for the 15 revisions were dislocations (n = 8) and periprosthetic joint infections (PJI; n = 4, all on disease-modifying antirheumatic drugs (DMARDs)). The ten-year cumulative incidence of reoperation was 6.1%, with the most common indications being wound infections (six cases, four on DMARDs) and postoperative periprosthetic femur fractures (two cases, both uncemented femoral components). The ten-year cumulative incidence of complications not requiring reoperation was 13.1%, with the most common being intraoperative periprosthetic femur fracture (15 cases, 14 uncemented femoral components; p = 0.13). Radiological evidence of early femoral component subsidence was observed in six cases (all uncemented). Only one femoral component ultimately developed aseptic loosening. Harris Hip Scores substantially improved (p < 0.001).

Conclusion

Contemporary primary THAs with HXLPE in patients with inflammatory arthritis had excellent survivorship and good functional outcomes regardless of fixation method. Dislocation, PJI, and periprosthetic fracture were the most common complications in this cohort with inflammatory arthritis.

Non-drug and surgical treatment algorithm and recommendations for the 2020 update of the Japan College of Rheumatology clinical practice guidelines for the management of rheumatoid arthritis-secondary publication

OBJECTIVES

The aim of this study was to update the Japan College of Rheumatology (JCR) clinical practice guidelines (CPGs) for the management of rheumatoid arthritis (RA) and prepare an algorithm for non-drug and surgical treatments. This article is a digest version of the guidelines.

METHODS

The Japanese Ministry of Health, Labour and Welfare's research group, in collaboration with the JCR, used the Grading of Recommendations, Assessment, Development, and Evaluation method to update the 2014 JCR CPG for RA. The consensus was formed by CPG panel members.

RESULTS

We raised 19 clinical questions regarding non-drug and surgical treatments for RA and developed recommendations. The treatments included exercise therapy; occupational therapy; joint injection of corticosteroids; and orthopaedic surgeries including cervical spine surgery, wrist and foot arthroplasty, ankle arthrodesis, and replacement arthroplasty of the shoulder, elbow, finger, hip, knee, and ankle. Recommendations regarding the risks of surgery and perioperative discontinuation of medications have also been developed. Based on these recommendations, we created an original algorithm for the non-drug and surgical treatment of RA.

CONCLUSIONS

These recommendations are expected to serve rheumatologists, health care professionals, and patients with RA as tools for shared decision-making to treat residual limb joint symptoms and functional impairment.

Total Hip Replacement in Patients with Rheumatoid Arthritis: Trends in Incidence and Complication Rates Over 35 Years

INTRODUCTION

Advances in rheumatoid arthritis (RA) management have made disease remission achievable. We evaluated trends in total hip replacement (THR) and postoperative outcomes in patients with RA in Western Australia (WA) over more than three decades.

METHODS

This was a retrospective analysis of routinely collected prospective data from a state-wide registry containing longitudinally linked administrative health data based on International Classification of Diseases (ICD) diagnostic and procedural codes. We included patients with two or more diagnostic codes for RA (between 1980 and 2015) and studied THR incidence rates (THR IR) and complication rates (revision, peri-prosthetic fracture, infection, venous thrombosis, and mechanical loosening). Survival rates were estimated by Kaplan-Meier method and predictors analyzed by Cox regression.

RESULTS

We followed 9201 RA patients over 111,625 person-years, during which 1560 patients (16.9%) underwent THR. From 1985 to 2015, THR IR (per 1000 RA patient-years) decreased from 20.8 (95% CI 20.1-21.5) to 7.3 (95% CI 7.2-7.5), and 5-year THR-free survival increased from 84.3 to 95.3% (1980-2015). Ten-year prosthetic survival was 91.2%. Complication rates in the first 5 years post-THR decreased significantly from 13.1 to 3.7% (p < 0.001). Mechanical complications such as loosening and periprosthetic fracture rates decreased significantly (> 35%, P < 0.05), while infection and revision did not change over the observation period (p > 0.05).

CONCLUSIONS

Over the last 30 years in RA patients, THR IR and mechanical complication rates decreased significantly, but the medical complication of infection has not changed significantly.

Bone mineral density assessment by DXA in rheumatic patients with end-stage osteoarthritis undergoing total joint arthroplasty

BACKGROUND

Patients with rheumatic diseases have a high risk for joint destruction and secondary osteoarthritis (OA) as well as low bone mineral density (BMD, i.e., osteoporosis). While several factors may lead to low BMD in these patients, the value of BMD measurements in rheumatic patients with end-stage OA scheduled for total joint arthroplasty is unknown.

METHODS

In this retrospective cross-sectional study of 50 adults with secondary OA due to rheumatic diseases, we evaluated dual energy X-ray absorptiometry (DXA) measurements of both hips and the spine performed within 3 months prior to arthroplasty (n = 25 total hip arthroplasty, THA; n = 25 total knee arthroplasty, TKA). We analyzed various demographic and disease-specific characteristics and their effect on DXA results by using group comparisons and multivariate linear regression models.

RESULTS

Although patients undergoing TKA were younger (63.2 ± 14.2 vs. 71.0 ± 10.8 yr., p = 0.035), osteoporosis was observed more frequently in patients scheduled for TKA than THA (32% vs. 12%). Osteopenia was detected in 13/25 patients (52%) in both the THA and TKA cohort. In the THA cohort, female sex, lower BMI and prednisolone use were associated with lower T-score in the hip. In TKA patients, higher OA grade determined by Kellgren-Lawrence score was associated with lower T-score in the hip of the affected side.

CONCLUSIONS

Osteoporosis is present in a considerable frequency of rheumatic patients with end-stage OA, and THA and TKA patients show distinct frequencies and risk factors of low BMD. Our findings point to a potential value of DXA regarding preoperative evaluation of bone status.

Incidence and Complication Rates for Total Hip Arthroplasty in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis Across Four Decades

INTRODUCTION

Over the past several decades, management of rheumatoid arthritis (RA) has evolved significantly, but few studies have examined the real-world impact of these changes on orthopaedic surgery in patients with RA. This systematic review assessed total hip arthroplasty (THA) incidence and postoperative complication rates across the past four decades.

METHODS

This is a systematic literature review sourcing data on THA in patients with RA from the electronic databases MEDLINE, EMBASE, Scopus, and Cochrane between January 1, 1980 and December 31, 2019.

RESULTS

The search retrieved 1715 articles of which 44 were included for quantitative synthesis. The rate for THA decreased by almost 40% from 11/1000 patient years (PY) in the 2000s to 7/1000 PY in the 2010s, while the overall complication rate decreased from 9.9% in the 1990s to 5.3% in the 2010s. Throughout the duration of the study, THA incidence and overall complication rate decreased. However, not all individual complication rates decreased. For example, revision and periprosthetic fracture decreased, infection and aseptic loosening remained constant, and dislocation increased.

CONCLUSION

Medical management of patients with RA has reduced the need for THA, while postoperative medical and surgical management has improved some postoperative outcomes. Nevertheless, there remains room for further improvement to postoperative outcomes through RA-specific management.

Acetabular cup migration after primary cementless total hip arthroplasty in rheumatoid arthritis and its influencing factors: a comparative study with osteoarthritic hip

PURPOSE

To compare the radiographic migration profiles of primary cementless total hip arthroplasty (THA) between patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA).

METHODS

A total of 197 patients (215 hips) who underwent cementless THA for RA or OA between January 2001 and January 2013 and followed up for a minimum of 5.5 years were included. Ninety-four RA patients (109 hips) were compared with 103 OA patients (106 hips). Radiological evaluation was performed for acetabular cup loosening, and cup migration was measured using Einzel-Bild-Röntgen-Analyse (EBRA) software. Multiple variables were assessed to identify influencing factors for cup migration.

RESULTS

Early cup migration was observed in 13 hips (11.9%) in the RA group and four hips (3.8%) in the OA group, showing a significant difference (p = 0.041). Acetabular cup loosening occurred in three cups (2.8%) in the RA group and in one cup (0.9%) in the OA group, showing no significant difference (p = 0.321). Total cup migration was higher in the RA group (2.62 mm) than in the OA group (1.44 mm, p = 0.005). Total cup migration was significantly higher in patients aged < 50 years than in those aged > 50 years (p = 0.005). Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody influenced total cup migration. Patients with seropositive RA showed significantly higher total cup migration and early cup migration incidence than those with seronegative RA (p = 0.005, p = 0.038, respectively).

CONCLUSIONS

Acetabular cups in primary cementless THAs of RA patients were less stable in terms of cup migration compared with that of OA patients.

Rheumatoid arthritis disease activity and the risk of aseptic arthroplasty loosening

OBJECTIVES

To assess the influence of rheumatoid arthritis (RA) disease activity (DA) on the risk of aseptic loosening after total hip/knee arthroplasty (THA/TKA).

METHODS

We identified RA patients who underwent THA/TKA and determined their DA using the simplified disease activity index (SDAI). The risk of aseptic loosening was estimated using radiographic signs of component loosening (RCL). We performed Cox regression to estimate RCL based on SDAI, adjusting for therapy. We also investigated a cohort of 2:1 matched osteoarthritis (OA) patients as a control group without systemic inflammation.

RESULTS

We identified 49 RA patients with a history of THA/TKA, of whom 18 (36.7%) showed RCL. SDAI over time was significantly higher in patients with RCL (median; 25th and 75th percentile: 10.8 months; 8.6 and 15.8; vs 7.0 months; 2.7 and 15.5;p = 0.043). In the regression model, each unit of mean SDAI over time significantly increased the risk of RCL (HR 1.125, 95% CI 1.021-1.241;p = 0.018). Patients treated with biological had a lower risk of RCL than those treated with traditional DMARDs (HR 0.192, 95% CI 0.042-0.891;p = 0.035). In the 88 matched OA patients, the RCL rate was significantly lower than in the RA group (13.6%;p = 0.002).

CONCLUSION

Higher inflammatory DA increases the risk for radiographic loosening after THA/TKA in patients with RA. The significantly lower risk in patients with OA further underlines the potential role of inflammatory DA. In the context of treating RA to target, the presence of an arthroplasty might be considered as an indication for more stringent control of DA.

Risk Factors Associated With Short-term Clinical Results After Total Hip Arthroplasty for Patients With Rheumatoid Arthritis

Clinical outcomes of total hip arthroplasty for rheumatoid arthritis are reportedly worse than those of total hip arthroplasty for osteoarthritis of the hip. The authors examined pre- and postoperative factors associated with the modified Harris hip score (mHHS). Fifty-one joints of 48 rheumatoid arthritis patients who underwent total hip arthroplasty were studied retrospectively. The authors examined the correlation between preoperative rheumatoid arthritis disease activity (Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein) and mHHS at 1 year after total hip arthroplasty. Furthermore, pre- and postoperative mHHS values were compared between patients with other affected joints and patients with no affected joints in the lower limbs. The mean mHHS improved to 73.5 points postoperatively from 36.4 points preoperatively. Preoperative Disease Activity Score in 28 joints-C-reactive protein and C-reactive protein values were negatively correlated with pre- and postoperative mHHS values. Preoperative mHHS was not significantly different between the affected and not affected groups; however, postoperative mHHS was significantly lower in the affected group than in the not affected group. Total hip arthroplasty showed good clinical results for rheumatoid arthritis at short-term follow-up. However, pre- and postoperative mHHS values were influenced by preoperative rheumatoid arthritis disease activity. Moreover, the presence of additional affected joints in the lower limbs preoperatively resulted in a lower postoperative mHHS. Unlike patients with osteoarthritis, patients with rheumatoid arthritis often have multiple affected joints, which may contribute to a lower mHHS. Comprehensive treatment, including surgery for the other affected joints in the lower limbs, may improve a patient's postoperative mHHS. [Orthopedics. 2018; 41(6):e772-e776.].

[Change in rheumatic hip surgery]

There is a trend towards a reduction in joint-preserving hip surgery, such as synovectomy and total hip joint replacement in rheumatic patients. This is mostly due to the success of biological disease-modifying antirheumatic drugs (bDMARD) in systemic anti-rheumatic therapy. The results of hip surgery in rheumatic patients are comparable to those in non-rheumatic patients, except for prosthetic joint infections, which are higher in patients with rheumatoid arthritis. Especially in hip surgery there was a big evolution in the last few years including a broad range of minimally invasive surgical methods, such as hip arthroscopy, mini-open hip surgery and minimally invasive hip arthroplasty with bone preservation or short femoral shafts. These surgical methods also have an advantage in the treatment of typical rheumatoid pathologies and have the benefit of a rapid recovery.

Mid-term clinical outcome of constrained condylar knee prosthesis for patients with rheumatoid arthritis

Objectives: This study retrospectively investigated the mid-term outcome of Legacy constrained condylar knee (LCCK) prosthesis in patients with rheumatoid arthritis (RA) having severe varus/valgus deformity, instability, and/or bone loss. Methods: Between January 2000 and December 2015, LCCK prostheses had been performed in 32 knees of 25 patients with RA, and 23 knees of 17 patients of the postoperative follow-up minimum 2 years were analyzed in this study (Primary: 14 knees, Revision: 9 knees). The average of follow-up duration was 6.9 ± 2.7 years, all were female, and the average of age and RA duration at the surgery was 59.0 ± 9.5 years and 26.6 ± 13.5 years, respectively. Clinical result was analyzed by Knee Society Score (KSS) knee and function at preoperative time and final visit. Imaging outcome was investigated by femoral tibial angle (FTA), four component alignment angles, and radiolucent line at pre-/postoperative time. Results: KSS knee/function scores and radiographic FTAs were improved after operation. Radiolucent lines around components were seen in 17 knees (73.9%), of which only one knee (4.3%) has shown aseptic loosening. The seven-year Kaplan-Meier survivorship analysis resulted in 91.7%. Conclusion: LCCK prosthesis in RA patients was achieved to the excellent mid-term clinical and radiographic result.

The impact of rheumatoid arthritis on the risk of adverse events following joint replacement: a real-world cohort study

Purpose

To assess whether rheumatoid arthritis (RA) is associated with a greater risk of adverse events following total knee replacement (TKR) and total hip replacement (THR) than osteoarthritis (OA).

Patients and methods

Individuals with a diagnosis of RA or OA were identified using primary care records. TKR and THR following diagnosis were identified using linked hospital records. Myocardial infarction (MI), prosthetic joint infection (PJI), venous thromboembolism (VTE), and death were identified within 90 days following surgery, and revision procedures over 10 years following surgery. The impact of RA compared to OA on the risk for these adverse events was assessed using Cox proportional hazard models. Univariable models, with diagnosis as the only explanatory variable, and multivariable models, with age, gender, and year of surgery first added and then a measure of other comorbidities also included, were estimated.

Results

In all 20,763 individuals, with 10,260 TKR and 10,961 THR, were included in the analysis. Compared to those with OA, individuals with a diagnosis of RA had a greater incidence of MI over 90 days following TKR (OA: 0.28%, RA: 0.75%) and revision over 10 years following THR (OA: 5.55%, RA: 8.68%). Both of these differences were statistically significant with, for example, hazard ratios of 3.54 (1.44 to 8.73) for MI and 1.61 (1.06 to 2.46) for revision after controlling for age, gender, year of surgery, and other comorbidities.

Conclusion

These findings suggest that, compared to individuals with OA, those with RA have an increased short-term risk of MI following TKR. While risk of MI remains below 1%, this does underline the importance of the management of cardiovascular risk factors for those with RA. RA was also associated with an increased long-term risk of revision following THR, which strengthens the argument for investing in therapies which may prevent the need for joint replacement.

Predictors of revision, prosthetic joint infection and mortality following total hip or total knee arthroplasty in patients with rheumatoid arthritis: a nationwide cohort study using Danish healthcare registers

OBJECTIVES

To investigate predictors of 10-year risk of revision and 1-year risk of prosthetic joint infection (PJI) and death following total hip/total knee arthroplasty (THA/TKA) in (1) patients with rheumatoid arthritis (RA) compared with patients with osteoarthritis (OA); and (2) patients with RA treated with biological disease-modifying antirheumatic drugs (bDMARD) within 90 days preceding surgery compared with non-treated.

METHODS

Register-based cohort study using the Danish National Patient Register, the DANBIO rheumatology register (RA-specific confounders and treatment episodes) and the Danish Hip and Knee Arthroplasty Registers. Survival analyses were used to calculate confounder-adjusted sub-HRs (SHR) and HRs.

RESULTS

In total, 3913 patients with RA with THA/TKA were compared with 120 499 patients with OA. Patients with RA had decreased risk of revision (SHR 0.71 (0.57-0.89)), but increased risk of PJI (SHR=1.46 (1.13-1.88)) and death (HR=1.25 (1.01-1.55)). In DANBIO, 345 of 1946 patients with RA with THA/TKA had received bDMARD treatment within 90 days preceding surgery. bDMARD-treated patients did not have a statistically significant increased risk of revision (SHR=1.49 (0.65-3.40)), PJI (SHR=1.61 (0.70-3.69)) nor death (HR=0.75 (0.24-2.33)) compared with non-treated. Glucocorticoid exposure (HR=2.87 (1.12-7.34)) and increasing DAS28 (HR=1.49 (1.01-2.20)) were risk factors for mortality.

CONCLUSION

Patients with RA had a decreased 10-year risk of revision while the risk of death and PJI was increased compared with patients with OA following THA/TKA. bDMARD exposure was not associated with statistically significant increased risk of neither PJI nor death in this study. Glucocorticoid exposure and increased disease activity were associated with an increased risk of death.

Clinical Factors, Disease Parameters, and Molecular Therapies Affecting Osseointegration of Orthopedic Implants

Total hip and knee arthroplasty are effective interventions for management of end-stage arthritis. Indeed, about 7 million Americans are currently living with artificial hip and knee joints. The majority of these individuals, however, will outlive their implants and require revision surgeries, mostly due to poor implant osseointegration and aseptic loosening. Revisions are potentially avoidable with better management of patient-related risk factors that affect the osseointegration of orthopedic implants. In this review, we summarize the published clinical literature on the role of demographics, biologic factors, comorbidities, medications and aseptic loosening risk. We focus on several systemic and local factors that are particularly relevant to implant osseointegration. Examples include physiological and molecular processes that are linked to hyperglycemia, oxidative stress, metabolic syndrome and dyslipidemia. We discuss how orthopedic implant osseointegration can be affected by a number of molecular therapies that are antiresorptive or bone anabolic (i.e. calcium, vitamin D, bisphosphonates, calcitonin, strontium, hormone replacement therapy, selective estrogen-receptor modulators).

A review of UHMWPE wear-induced osteolysis: the role for early detection of the immune response

In a world where increasing joint arthroplasties are being performed on increasingly younger patients, osteolysis as the leading cause of failure after total joint arthroplasty (TJA) has gained considerable attention. Ultra-high molecular weight polyethylene wear-induced osteolysis is the process by which prosthetic debris mechanically released from the surface of prosthetic joints induces an immune response that favors bone catabolism, resulting in loosening of prostheses with eventual failure or fracture. The immune response initiated is innate in that it is nonspecific and self-propagating, with monocytic cells and osteoclasts being the main effectors. To date, detecting disease early enough to implement effective intervention without unwanted systemic side effects has been a major barrier. These barriers can be overcome using newer in vivo imaging techniques and modules linked with fluorescence and/or chemotherapies. We discuss the pathogenesis of osteolysis, and provide discussion of the challenges with imaging and therapeutics. We describe a positron emission tomography imaging cinnamoyl-Phe-(D)-Leu-Phe-(D)-Leu-Phe-Lys module, specific to macrophages, which holds promise in early detection of disease and localization of treatment. Further research and increased collaboration among therapeutic and three-dimensional imaging researchers are essential in realizing a solution to clinical osteolysis in TJA.

Cementless total hip arthroplasty for patients with rheumatoid arthritis: a more than 10-year follow-up

BACKGROUND/PURPOSE

In this study, cementless THA was performed for RA patients, and its clinical outcomes, as well as radiographic findings and implant survival rates, were examined more than 10 years after surgery in comparison with the outcomes of the same procedure performed for patients with hip osteoarthritis (OA) during the same period.

METHOD

We studied 28 cases of THA for RA clinically and radiologically at a minimum follow-up duration of 10 years. The patients consisted of 4 males and 22 females, with a mean age at the time of surgery of 53.1. The clinical and radiographic results were compared with an age-matched and sex-matched group of patients who had undergone THA for the diagnosis of primary or secondary OA.

RESULTS

In the RA group, the mean Harris hip score was 48.3 before surgery, and improved to 76.8 at the time of the final survey. In the control group, the score also improved from 46.8 before to 86.5 after surgery, while revealing significant differences between the groups (p = 0.0002). In the RA group, 2 joints required revision THA on the acetabular side due to aseptic loosening, while such revision was not performed on the femoral side despite the presence of more than 2 mm of subsidence in 2 joints. The implant survival rate was 92.9 and 100 % in the RA and control groups, respectively, without significant differences (p = 0.493).

CONCLUSIONS

Although its clinical outcomes were significantly different from those for OA, a satisfactory implant survival rate was achieved, at 92.9 % in RA patients.

Similar effect of stem geometry on radiological changes with 2 types of cemented straight stem: The Müller stem and the Virtec stem compared in 711 hips

BACKGROUND AND PURPOSE

There are 2 basic principles in cemented stem fixation: shape-closed and force-closed. We investigated 2 shape-closed straight stems, the Müller (MSS) and the Virtec (VSS), which differ only in geometrical cross section, to determine whether the difference in stem shape would affect the radiological results or long-term survival.

PATIENTS AND METHODS

We included 711 hips (in 646 patients) that were operated on between July 1996 and July 2003. Patients randomly received either an MSS (n = 356) or a VSS (n = 355) and were followed prospectively. Radiographs taken at a follow-up of > 10 years were analyzed for osteolysis. Kaplan-Meier (KM) survival analysis was performed using various endpoints. We also performed Cox regression analysis to identify risk factors for aseptic loosening and osteolysis of the stem.

RESULTS

After 10 years, KM survival with "revision of any component for any reason" was 92% (95% CI: 88-95) for the MSS and 95% (CI: 92-97) for the VSS (p = 0.1). With "revision for aseptic loosening of the stem" as the endpoint, KM survival was 96% (CI: 9-98) for the MSS and 98% (CI: 97-100) for the VSS (p = 0.2). Cox regression showed that none of the risk factors analyzed were independent regarding aseptic loosening of the stem or regarding osteolysis.

INTERPRETATION

The MSS and the VSS showed excellent survival for aseptic loosening after 10 years. For the 2 different stem designs, we did not find any independent risk factors for aseptic loosening or development of osteolysis.

Brief Report: Methotrexate Prevents Wear Particle-Induced Inflammatory Osteolysis in Mice Via Activation of Adenosine A2A Receptor

OBJECTIVE

Adenosine, acting at the A2A receptor, mediates the antiinflammatory effects of methotrexate (MTX) in models of inflammation. We previously reported that A2A receptor ligation diminishes wear particle-driven osteolysis. The aim of this study was to investigate whether MTX treatment could prevent bone resorption caused by inflammatory osteolysis.

METHODS

C57BL/6 mice (6-8 weeks old) received intraperitoneal injections of 1 mg/kg MTX (n = 20) or 0.9% saline (n = 10), starting 2 weeks prior to surgical implantation of 3 mg of wear particles (ultrahigh molecular weight polyethylene [UHMWPE] particles). The MTX-treated mice received daily injections of vehicle or ZM241385 at the surgical site until they were killed, 14 days later. XenoLight RediJect Bone Probe 680 was injected intravenously, and fluorescence analysis of the calvaria using an IVIS imaging system was performed to assess bone formation. Micro-computed tomography (micro-CT) and immunostaining for osteoclast and osteoblast markers were performed.

RESULTS

Implantation of wear particles induced bone pitting and thinning, as shown by micro-CT. MTX treatment markedly reduced osteolysis, and this effect was abrogated by treatment with the A2A receptor antagonist ZM241385. Implantation of UHMWPE reduced new bone formation, and MTX treatment restored new bone formation, an effect that was completely reversed by treatment with ZM241385. Histologic examination of particle-exposed calvariae demonstrated that MTX prevented accumulation of an inflammatory infiltrate at the site of particle implantation, increased the number of osteoblasts, and reduced the number of osteoclasts at the site of inflammation, an effect that was reversed by treatment with ZM241385.

CONCLUSION

MTX reduces inflammatory osteolysis indirectly via stimulation of A2A receptor and may represent a novel approach to enhance orthopedic implant survival, delaying or eliminating the need for revision arthroplasty surgery.

Total hip replacement and surface replacement for the treatment of pain and disability resulting from end-stage arthritis of the hip (review of technology appraisal guidance 2 and 44): systematic review and economic evaluation

BACKGROUND

Total hip replacement (THR) involves the replacement of a damaged hip joint with an artificial hip prosthesis. Resurfacing arthroplasty (RS) involves replacement of the joint surface of the femoral head with a metal surface covering.

OBJECTIVES

To undertake clinical effectiveness and cost-effectiveness analysis of different types of THR and RS for the treatment of pain and disability in people with end-stage arthritis of the hip, in particular to compare the clinical effectiveness and cost-effectiveness of (1) different types of primary THR and RS for people in whom both procedures are suitable and (2) different types of primary THR for people who are not suitable for hip RS.

DATA SOURCES

Electronic databases including MEDLINE, EMBASE, The Cochrane Library, Current Controlled Trials and UK Clinical Research Network (UKCRN) Portfolio Database were searched in December 2012, with searches limited to publications from 2008 and sample sizes of ≥ 100 participants. Reference lists and websites of manufacturers and professional organisations were also screened.

REVIEW METHODS

Systematic reviews of the literature were undertaken to appraise the clinical effectiveness and cost-effectiveness of different types of THR and RS for people with end-stage arthritis of the hip. Included randomised controlled trials (RCTs) and systematic reviews were data extracted and risk of bias and methodological quality were independently assessed by two reviewers using the Cochrane Collaboration risk of bias tool and the Assessment of Multiple Systematic Reviews (AMSTAR) tool. A Markov multistate model was developed for the economic evaluation of the technologies. Sensitivity analyses stratified by sex and controlled for age were carried out to assess the robustness of the results.

RESULTS

A total of 2469 records were screened of which 37 were included, representing 16 RCTs and eight systematic reviews. The mean post-THR Harris Hip Score measured at different follow-up times (from 6 months to 10 years) did not differ between THR groups, including between cross-linked polyethylene and traditional polyethylene cup liners (pooled mean difference 2.29, 95% confidence interval -0.88 to 5.45). Five systematic reviews reported evidence on different types of THR (cemented vs. cementless cup fixation and implant articulation materials) but these reviews were inconclusive. Eleven cost-effectiveness studies were included; four provided relevant cost and utility data for the model. Thirty registry studies were included, with no studies reporting better implant survival for RS than for all types of THR. For all analyses, mean costs for RS were higher than those for THR and mean quality-adjusted life-years (QALYs) were lower. The incremental cost-effectiveness ratio for RS was dominated by THR, that is, THR was cheaper and more effective than RS (for a lifetime horizon in the base-case analysis, the incremental cost of RS was £11,284 and the incremental QALYs were -0.0879). For all age and sex groups RS remained clearly dominated by THR. Cost-effectiveness acceptability curves showed that, for all patients, THR was almost 100% cost-effective at any willingness-to-pay level. There were age and sex differences in the populations with different types of THR and variations in revision rates (from 1.6% to 3.5% at 9 years). For the base-case analysis, for all age and sex groups and a lifetime horizon, mean costs for category E (cemented components with a polyethylene-on-ceramic articulation) were slightly lower and mean QALYs for category E were slightly higher than those for all other THR categories in both deterministic and probabilistic analyses. Hence, category E dominated the other four categories. Sensitivity analysis using an age- and sex-adjusted log-normal model demonstrated that, over a lifetime horizon and at a willingness-to-pay threshold of £20,000 per QALY, categories A and E were equally likely (50%) to be cost-effective.

LIMITATIONS

A large proportion of the included studies were inconclusive because of poor reporting, missing data, inconsistent results and/or great uncertainty in the treatment effect estimates. This warrants cautious interpretation of the findings. The evidence on complications was scarce, which may be because of the absence or rarity of these events or because of under-reporting. The poor reporting meant that it was not possible to explore contextual factors that might have influenced study results and also reduced the applicability of the findings to routine clinical practice in the UK. The scope of the review was limited to evidence published in English in 2008 or later, which could be interpreted as a weakness; however, systematic reviews would provide summary evidence for studies published before 2008.

CONCLUSIONS

Compared with THR, revision rates for RS were higher, mean costs for RS were higher and mean QALYs gained were lower; RS was dominated by THR. Similar results were obtained in the deterministic and probabilistic analyses and for all age and sex groups THR was almost 100% cost-effective at any willingness-to-pay level. Revision rates for all types of THR were low. Category A THR (cemented components with a polyethylene-on-metal articulation) was more cost-effective for older age groups. However, across all age-sex groups combined, the mean cost for category E THR (cemented components with a polyethylene-on-ceramic articulation) was slightly lower and the mean QALYs gained were slightly higher. Category E therefore dominated the other four categories. Certain types of THR appeared to confer some benefit, including larger femoral head sizes, use of a cemented cup, use of a cross-linked polyethylene cup liner and a ceramic-on-ceramic as opposed to a metal-on-polyethylene articulation. Further RCTs with long-term follow-up are needed.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013003924.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

An Insight into Methods and Practices in Hip Arthroplasty in Patients with Rheumatoid Arthritis

Total hip arthroplasty (THA) has improved the quality of life of patients with hip arthritis. Orthopedic community is striving for excellence to improve surgical techniques and postoperative care. Despite these efforts, patients continue facing postoperative complications. In particular, patients with rheumatoid arthritis display a higher risk of certain complications such as dislocation, periprosthetic infection, and shorter prosthesis durability. In this review we present the current knowledge of hip arthroplasty in patients with rheumatoid arthritis with more insight into common practices and interventions directed at enhancing recovery of these patients and current shortfalls.

Increased risk of revision for infection in rheumatoid arthritis patients with total hip replacements

BACKGROUND AND PURPOSE

Medical treatment of rheumatoid arthritis (RA) has changed dramatically over the last 15 years, including immune modulation. We investigated the risk of revision for infection after primary total hip replacement (THR) in patients with rheumatoid arthritis over a 16-year period, and compared it with that in THR patients with osteoarthritis (OA).

PATIENTS AND METHODS

We identified 13,384 THRs in RA patients and 377,287 THRs in OA patients from 1995 through 2010 in a dataset from the Nordic Arthroplasty Register Association (NARA). Kaplan-Meier survival curves, with revision for infection as the endpoint, were constructed. Cox regression analyses were performed to calculate the relative risk (RR) of revision for infection adjusted for age, sex, fixation technique, and year of primary surgery.

RESULTS

RA patients had a 1.3 times (95% CI 1.0-1.6) higher risk of revision for infection. After 2001, this risk increased more for RA patients than for OA patients. During the first 3 months and from 8 years postoperatively, the risk of revision for infection was higher in RA patients with THRs fixated with antibiotic-loaded cement than in corresponding OA patients.

INTERPRETATION

We found a slightly higher overall risk of revision for infection in RA patients than in OA patients, but this difference was only present after 2001. In THRs with antibiotic-loaded cement, the risk of very early and late infections leading to revision was higher in RA patients than in OA patients.

Cemented total hip arthroplasty in rheumatoid arthritis. A systematic review of the literature

BACKGROUND

Cemented total hip arthroplasty (THA) in rheumatoid arthritis (RA) is allegedly associated with increased rates of infection, dislocation and aseptic loosening of cup and stem.

METHOD

Systematic review of the literature on clinical and radiological results of cemented THA in RA.

RESULTS

Twenty-one case series and eight reports on four implant registries were included. The quality of most studies was judged to be poor. The reported rates of infection and dislocation in the case series were conflicting with a risk of bias due to under-registration. The registries proved unsuitable for providing reliable data on the incidence of these two complications. Increased rates of aseptic loosening were reported in 10 out of 20 case series on the cup and in six out of 19 on the stem. Nearly all of these were based on series implanted before 1980. None of the registries reported a significantly increased risk of aseptic loosening of cup or stem.

CONCLUSIONS

Considering the relatively frequent reports of increased infection rates in combination with the potential under-registration of complications, RA patients have to be considered to have a mild increased risk of postoperative infection. Case series and registries cannot answer the question of whether RA is a risk factor for dislocation as multivariate analysis is required. Increased rates of cup and stem failure due to aseptic loosening in RA patients are found in older but not in more recent studies.

Risk factors for aseptic loosening of Müller-type straight stems: a registry-based analysis of 828 consecutive cases with a minimum follow-up of 16 years

Background and purpose Even small differences in design variables for the femoral stem may influence the outcome of a hip arthroplasty. We performed a risk factor analysis for aseptic loosening of 4 different versions of cemented Müller-type straight stems with special emphasis on design modifications (2 shapes, MSS or SL, and 2 materials, CoNiCrMo (Co) or Ti-6Al-7Nb (Ti)). Methods We investigated 828 total hip replacements, which were followed prospectively in our in-house register. All stems were operated in the same setup, using Sulfix-6 bone cement and a second-generation cementing technique. Demographic and design-specific risk factors were analyzed using an adjusted Cox regression model. Results The 4 versions showed marked differences in 15-year stem survival with aseptic loosening as the endpoint: 94% (95% CI: 89-99) for MSS Co, 83% (CI: 75-91) for SL Co, 81% (CI: 76-87) for MSS Ti and 63% (CI: 56-71) for SL Ti. Cox regression analysis showed a relative risk (RR) for aseptic loosening of 3 (CI: 2-5) for stems made of Ti and of 2 (CI: 1-2) for the SL design. The RR for aseptic stem loosening increased to 8 (CI: 4-15) when comparing the most and the least successful designs (MSS Co and SL Ti). Interpretation Cemented Müller-type straight stems should be MSS-shaped and made of a material with high flexural strength (e.g. cobalt-chrome). The surface finish should be polished (Ra < 0.4 µm). These technical aspects combined with modern cementing techniques would improve the survival of Müller-type straight stems. This may be true for all types of cemented stems.

Medical comorbidity is associated with persistent index hip pain after total hip arthroplasty

OBJECTIVE

To characterize whether medical comorbidity predicts persistent moderate-severe pain after total hip arthroplasty (THA).

METHODS

We analyzed the prospectively collected data from the Mayo Clinic Total Joint Registry for patients who underwent primary or revision THA between 1993 and 2005. Using multivariable-adjusted logistic regression analyses, we examined whether certain medical comorbidities were associated with persistent moderate-severe hip pain 2 or 5 years after primary or revision THA. Odds ratios (ORs), along with 95% confidence intervals (CIs) and P value, are presented.

RESULTS

The primary THA cohort consisted of 5,707 THAs and 3,289 THAs at 2 and 5 years, and revision THA, 2,687 and 1,627 THAs, respectively. In multivariable-adjusted logistic regression models, in the primary THA cohort, renal disease was associated with lower odds of moderate-severe hip pain (OR 0.6; 95% CI 0.3, 1.0) at 2 years. None of the comorbidities were significantly associated at 5 years. In the revision THA cohort, heart disease was significantly associated with higher risk (OR 1.7; 95% CI 1.1, 2.6) at 2 years and connective tissue disease with lower risk (OR 0.5; 95% CI 0.3, 0.9) of moderate-severe hip pain at 5-year follow-up.

CONCLUSION

This study identified new correlates of moderate-severe hip pain after primary or revision THA, a much-feared outcome of hip arthroplasty. Patients with these comorbidities should be informed regarding the risk of moderate-severe index hip pain, so that they can have a fully informed consent and realistic expectations.

Hip score and disease activity correlation in patients with rheumatoid arthritis after total hip arthroplasty

PURPOSE

The disease activity score including 28 joints (DAS28), the simplified disease activity index and the clinical disease activity index (CDAI) were developed in order to provide a quantifiable measure of rheumatoid arthritis (RA) activity. Although inflamed hip joints greatly impact activities of daily living (ADL) and walking ability, the hip joint was not included in the DAS28, SDAI or CDAI assessments. Although excellent clinical results have been reported for total hip arthroplasty (THA) in RA patients, correlations between disease activity and hip function in RA patients after THA remain unknown.

METHODS

We analysed the effect of RA disease activity on a hip function score in an observational cohort of RA patients after THA. Twenty-five registered RA patients who had undergone THA (33 joints) were included. Hip function was recorded and RA disease activity was measured on the same day. The mean age of the patients was 65.17 years. They were followed up for a mean of 5.24 years after surgery. The mean duration of disease following RA diagnosis for this patient group was 19.47 years. The Japanese Orthopaedic Association (JOA) hip score was used as a clinical outcome measure for hip dysfunction. RA disease activity and health-related quality of life were measured using the DAS28, SDAI, CDAI and the modified health assessment questionnaire (MHAQ).

RESULTS

The mean JOA score for hip function was 80.48 at the final follow-up. The mean DAS28-ESR, DAS28-CRP, SDAI, CDAI and MHAQ measuring RA disease activity levels were 3.38, 2.65, 9.59, 8.63 and 0.44, respectively, at the final follow-up. There was a significant negative correlation between the JOA hip score and all disease activity assessments observed after THA (DAS-ESR [P = 0.0067], DAS-CRP [P = 0.0008]), SDAI [P = 0.0034], CDAI [P = 0.0003]) and MHAQ [P = 0.0002]).

CONCLUSION

We found significant negative correlations between JOA hip scores and all disease activity assessments in RA patients treated with THA.

A systematic review and meta-analysis comparing complications following total joint arthroplasty for rheumatoid arthritis versus for osteoarthritis

OBJECTIVE

Most of the evidence regarding complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA) is based on studies of patients with osteoarthritis (OA), with little being known about outcomes in patients with rheumatoid arthritis (RA). The objective of the present study was to review the current evidence regarding rates of THA/TKA complications in RA versus OA.

METHODS

Data sources used were Medline, EMBase, Cinahl, Web of Science, and reference lists of articles. We included reports published between 1990 and 2011 that described studies of primary total joint arthroplasty of the hip or knee and contained information on outcomes in ≥200 RA and OA joints. Outcomes of interest included revision, hip dislocation, infection, 90-day mortality, and venous thromboembolic events. Two reviewers independently assessed each study for quality and extracted data. Where appropriate, meta-analysis was performed; if this was not possible, the level of evidence was assessed qualitatively.

RESULTS

Forty studies were included in this review. The results indicated that patients with RA are at increased risk of dislocation following THA (adjusted odds ratio 2.16 [95% confidence interval 1.52-3.07]). There was fair evidence to support the notion that risk of infection and risk of early revision following TKA are increased in RA versus OA. There was no evidence of any differences in rates of revision at later time points, 90-day mortality, or rates of venous thromboembolic events following THA or TKA in patients with RA versus OA. RA was explicitly defined in only 3 studies (7.5%), and only 11 studies (27.5%) included adjustment for covariates (e.g., age, sex, and comorbidity).

CONCLUSION

The findings of this literature review and meta-analysis indicate that, compared to patients with OA, patients with RA are at higher risk of dislocation following THA and higher risk of infection following TKA.

Intermediate- to long-term results after hybrid total hip arthroplasty in patients with rheumatoid arthritis

There have been few reports describing intermediate- to long-term results after hybrid total hip arthroplasty in patients with rheumatoid arthritis. We followed up 52 hips in 44 patients aged 5 men and 39 women, with a mean of 11.5 years (range, 5-23.5 years). Revisions had been performed in 6 hips in 6 patients: 1 both acetabular and femoral components for infection, 1 acetabular component for aseptic loosening, 3 acetabular components for recurrent dislocation, and 1 acetabular component for dislodgement of the polyethylene liner from the metal shell. None of other acetabular or femoral components were revised or found to be loose at the final follow-up. Although postoperative dislocation remains a concern, hybrid total hip arthroplasty had an acceptable result in patients with rheumatoid arthritis.

Risk factors for revision of primary total hip arthroplasty: a systematic review

BACKGROUND

Numerous papers have been published examining risk factors for revision of primary total hip arthroplasty (THA), but there have been no comprehensive systematic literature reviews that summarize the most recent findings across a broad range of potential predictors.

METHODS

We performed a PubMed search for papers published between January, 2000 and November, 2010 that provided data on risk factors for revision of primary THA. We collected data on revision for any reason, as well as on revision for aseptic loosening, infection, or dislocation. For each risk factor that was examined in at least three papers, we summarize the number and direction of statistically significant associations reported.

RESULTS

Eighty-six papers were included in our review. Factors found to be associated with revision included younger age, greater comorbidity, a diagnosis of avascular necrosis (AVN) as compared to osteoarthritis (OA), low surgeon volume, and larger femoral head size. Male sex was associated with revision due to aseptic loosening and infection. Longer operating time was associated with revision due to infection. Smaller femoral head size was associated with revision due to dislocation.

CONCLUSIONS

This systematic review of literature published between 2000 and 2010 identified a range of demographic, clinical, surgical, implant, and provider variables associated with the risk of revision following primary THA. These findings can inform discussions between surgeons and patients relating to the risks and benefits of undergoing total hip arthroplasty.

Tibial component designs in primary total knee arthroplasty: should we reconsider all-polyethylene component?

PURPOSE

Despite the frequency with which total knee arthroplasties (TKAs) are performed, whether they are best performed using all-polyethylene or metal-backed tibial components remains a controversy. The aim of the present study was to determine the advantages and disadvantages of metal-backed compared with all-polyethylene tibial components during TKAs through an evaluation of current literature.

METHODS

A meta-analysis and systematic review of randomized and non-randomized comparative studies comparing metal-backed with all-polyethylene tibial components during TKAs were performed. The focus of the analysis was on the outcomes of knee score, range of motion (ROM), quality of life, implant alignment, tibial migration, radiolucent line, complication, reoperation, and implant survivorship.

RESULTS

A total of 10 randomized/quasi-randomized controlled trials and 13 non-randomized comparative studies assessing 19,767 TKAs were eligible. On the basis of these studies, no significant differences were found between the 2 groups with regard to knee score, ROM, quality of life, complication, and reoperation. The findings indicated that using all-polyethylene tibial components is associated with lower continuous migration rate compared with metal-backed tibial components. Only 13 studies provided adequate data on implant survivorship during intermediate or long-term follow-up. Of these, 9 found that no statistical significance existed between the 2 groups. The other 3 studies found that using all-polyethylene components yielded a higher survival rate than using metal-backed components.

CONCLUSIONS

Metal-backed tibial components had no obvious advantages over all-polyethylene tibial components in TKAs. However, this finding should be interpreted with caution due to publication bias, low methodological quality of the included studies, and different surgical interventions.

LEVEL OF EVIDENCE

Therapeutic study (systematic review and meta-analysis), Level III.

Cementless total hip arthroplasty in rheumatoid arthritis: a systematic review of the literature

BACKGROUND

Compromised rheumatic bone is a potential risk factor for mechanical complications in cementless total hip arthroplasty (THA) in cases of rheumatoid arthritis (RA). Increased rates of intra-operative fractures, component migration and (early) aseptic loosening are to be expected. Despite this, cementless THA is performed in cases of RA.

METHODS

A literature search on cementless THA in RA was performed in EMBASE (1993-2011), Medline (1966-2011) and the Cochrane Library. A systematic review was conducted with a special emphasis on mechanical complications.

RESULTS

Twenty-three case series and five studies of implant registries were included. Acetabular fractures and/or migration of the cup were reported in 9 out of 22 studies of the cup. Proximal femoral fractures and/or subsidence of the stem were reported in 14 out of 20 studies of the stem. Six studies compared failure rates of uncemented and cemented components due to aseptic loosening. The overall failure rate ratio (uncemented/cemented) for the cup was 0.6 (95% CI: 0.14-2.60) and for the stem 0.71 (95% CI: 0.06-8.55), both favoring uncemented fixation. The failure rates in case series without a control group were compared to the NICE criteria (failure rate/1). The overall failure rate for the cup was 0.97 (95% CI: 0.50-1.88) and for the stem 0.79 (95% CI: 0.44-1.41). Failure rates of aseptic loosening of higher than 1 (favoring cemented fixation) were reported in 6 out of 26 studies of the cup and in 2 out of 25 studies of the stem. In all these studies, the inferior implant designs were blamed, and not the type of fixation or the quality of the bone.

CONCLUSIONS

Despite substantial rates of mechanical stem complications, no evidence was found to establish that cementless components perform less well than cemented components. The results justify the use of cementless THA in RA patients.

[Endoprostheses of the hip joint]

In many cases rheumatoid arthritis leads to functional disturbances and deformities of the hip joint despite intensive conservative treatment. Joint replacement becomes necessary to preserve mobility and independence. The choice of implant and fixation system depends on the results of clinical and radiological examinations and the individual patient situation (e.g. age, bone quality, deformities of adjacent joints). The procedure, pre-operative and postoperative treatment, all require special expertise. If possible surgical procedures should be carried out in specialized surgical institutions by surgeons experienced in rheumatology and orthopedics.

Metal-on-metal hip resurfacing in rheumatoid patients. A report on thirteen hips with minimum 3 year follow-up

Rheumatoid disease can be extremely debilitating due to progressive joint destruction and multiple joint involvement. While there are varying results for THR in patients with RA, there is only one report of metal-on-metal resurfacing for rheumatoid patients with hip arthritis. We present preoperative and latest follow-up UCLA scores, SF-12 scores, HHS and range of motion in a series of 13 hips (10 patients). The patients experienced no complications associated with their resurfacing procedure and there have been no failures 3 to 13 years after surgery. Our results show that rheumatoid arthritis patients with hip involvement treated with metal-on-metal resurfacing can have extremely good outcomes.