Incidence and risk factors of prosthetic joint infection after total hip or knee replacement in patients with rheumatoid arthritis

Objective

Prosthetic joint infection is one of the most dreaded complications after total joint arthroplasty, a common procedure in patients with rheumatoid arthritis (RA). We conducted a study to evaluate potential risk factors of prosthetic joint infection and to clarify if RA is an independent predictor of this complication.

Methods

This study included all patients with RA who underwent total hip or knee replacement at the Mayo Clinic Rochester between January 1996 and June 2004. The association of potential risk factors with prosthetic joint infection was examined using Cox models. A matched cohort of patients with osteoarthritis (OA) was assembled to determine whether RA is an independent risk factor for prosthetic joint infection.

Results

We identified 462 patients with RA who underwent a total of 657 hip or knee replacements. Overall, 23 (3.7%) joint arthroplasties were complicated by an infection during a mean ± SD followup of 4.3 ± 2.4 years. Revision arthroplasty (hazard ratio [HR] 2.99, 95% confidence interval [95% CI] 1.02–8.75) and a previous prosthetic joint infection of the replaced joint (HR 5.49, 95% CI 1.87–16.14) were significant predictors of postoperative prosthetic joint infection. Comparison of RA patients with a matched cohort of OA patients identified an increased risk of prosthetic joint infections (HR 4.08, 95% CI 1.35–12.33) in patients with RA.

Conclusion

Patients with RA who undergo total hip or knee replacement are at increased risk of prosthetic joint infection, which is further increased in the setting of revision arthroplasty and a previous prosthetic joint infection. These findings highlight the importance of perioperative prophylactic measures and vigilance during the postoperative period.     

Sexual difficulties and total hip replacement in rheumatoid arthritis

Fifty-three patients with rheumatoid arthritis were interviewed by questionnaire. All the patients had undergone total hip replacement and were married at the time of operation. They were asked if they had had sexual difficulties because of hip pain or stiffness and if the hip operation had in any way alleviated these problems. Forty-four of the 53 patients answered the questionnaire. Twenty-eight patients had had sexual problems which they attributed to hip symptoms. Following total hip replacement the hips of 27 patients were no longer considered to be the cause of sexual difficulties, but in 10 of those patients other problems still rendered sexual life difficult.     

The impact of total joint replacement in rheumatoid arthritis

Management of the patient with rheumatoid arthritis (RA) requires a multidisciplinary approach, the role of the surgeon being to improve functional ability for the patient by reconstructing a deteriorated joint by total joint arthroplasty (TJA). An advantage of prosthetic evaluation over pharmacological medication evaluations is that the 'compliance' of the patient with the treatment (i.e. the TJA) is 100%, even at long-term follow-up. However, long-term follow-up of prosthesis evaluation is as difficult as the evaluation of any other intervention. Although the goal of any intervention on an RA patient is to improve functional ability, and thus self-support, of the patient, objective evaluation of the surgical procedure, and of its impact on the patient, can be difficult. The potential chronic course of RA makes evaluation of a specific surgical procedure and its effect on the patient difficult to interpret. The success of the TJA is generally judged on a survivorship analysis at 10 or 15 years in national registries (i.e. >40000 implants); revision surgery is used as an end-point for survival of the TJA. With a mean 90% survival at 10-year follow-up, total hip arthroplasty and total knee arthroplasty may be considered gold-standard TJA procedures for the patient. While revision is the end-point, the course to this end-point starts with progressive micromotion of the prosthesis. The effect of prosthetic changes, and of medication on prosthesis migration, can be measured very accurately by radiostereometry. The latter measures the actual performance of the TJA in the bone. Next to these more procedure-oriented evaluations, patient-oriented evaluations (e.g. quality of life, patient expectations) are of importance in judging the impact of the TJA on the RA patient. These evaluations provide evidence that the pre-operative status of the joint/extremity determines the extent of post-operative functional gain. Thus, postponing TJA for too long will give less functional benefit.     

Alignment of lower extremity in rheumatoid arthritis patients with a history of both total hip replacement and total knee replacement]

OBJECTIVE: The following is a retrospective study on lower extremity alignment of rheumatoid arthritis (RA) patients with a history of both Total Hip Replacement (THR) and Total Knee Replacement (TKR). METHODS: From 1992 to 2000, our department had 26 rheumatoid arthritis patients who underwent both THR and TKR. We classified these patients into three groups based on radiographic alignment of the lower extremities in the standing position: Knock-knee (valgus deformity of the knees), Bowleg (varus deformity of the knees) and Windswept Deformity (one knee in severe varus alignment with the other in severe valgus alignment). Furthermore, we identified dominant weight bearing points of the hip as classified by the following new criteria: Central Shift, Lateral Shift, and Upward Shift. Mal-alignment was then evaluated based on these two classification systems. RESULTS: Of the 26 patients, 22 patients met our criteria and 4 did not. In mal-alignment, we had 11 cases in the knock-knee group, 5 cases in the bowleg group, and 6 cases in the Windswept deformity. Using the new criteria, central shift had 6 cases; lateral shift had 6 cases; and upward shift had 10 cases. The groups of Lateral shift and Central shift demonstrated deformities of the lower extremities were influenced by moving weight bearing points, pelvis obliquity, and adduction contractures of the hip joint. In upward shift, weight bearing lines did not change. Consequently, destruction of the joint in this group progressed symmetrically. Windswept deformity was asymmetric and had severe destruction on the other side of the knee and forefoot. DISCUSSION: Moving of weight bearing point, pelvis obliquity, and adduction contractures of the hip joint affected the severity of mal-alignment of the lower extremities.     

Threefold increased risk of hip fractures with rheumatoid arthritis in Central Finland

OBJECTIVES—To evaluate the impact of rheumatoid arthritis (RA) on the incidence of hip fractures.METHODS—All patients with acute hip fractures admitted to Jyväskylä Central Hospital in 1991-93 (n=517) were selected from the hospital discharge register. Medical records of these patients were studied retrospectively for RA fulfilling the American Rheumatism Association criteria. The prevalence of RA in patients with hip fractures was compared with the prevalence rates of RA obtained from the nearby city of Tampere.RESULTS—29 (5.6%; 95% CI 3.8 to 8.0) of the patients with hip fracture in Jyväskylä Central Hospital had RA. The age and sex adjusted risk of hip fractures was increased by RA (risk ratio 3.26; 95% CI 2.26 to 4.70).CONCLUSIONS—Patients with RA are at increased risk of osteoporotic hip fractures.     

Computer aided analysis of total knee replacement in rheumatoid arthritis.

A computer-aided analysis has been carried out on 176 knee replacements performed on 129 patients during the last 12 years. Owing to the variety of knee replacements used, the number of complications seen, and the large quantity of survey data a computer was very helpful in storing this amount of data with facilities for rapid recall of information. The results of the early Shiers knee hinged arthroplasties have been less than 50% good results, and these were followed by many complications. A smaller number of other knee replacements have been analysed, namely, Freeman-Swanson, Gunston, Sheehan, and Attenborough. The best results were obtained using 60 Attenborough knee prostheses, with a low infection rate of 3.3%, a loosening rate of 5%, and good prospects of salvage by fusion of the knee if required.     

Cartilage and bone macromolecules in knee joint synovial fluid in rheumatoid arthritis: relation to development of knee or hip joint destruction

OBJECTIVE—To examine the hypothesis that aggrecan, cartilage oligomeric matrix protein (COMP), and bone sialoprotein (BSP) concentrations in synovial fluid could provide information on variations of progression of joint destruction in rheumatoid arthritis.
METHODS—Aggrecan, COMP, and BSP were quantified by enzyme linked immunosorbent assays in longitudinally collected knee joint synovial fluid samples of patients rapidly developing destruction in knees or hips, the "destructive" group, n = 18, and in patients slowly developing destruction, the "non-destructive" group, n = 25.
RESULTS—The aggrecan concentrations decreased from initially high levels (P << 0.001), and the BSP concentrations increased (P << 0.001) over time in the destructive group, whereas levels of both markers were low and did not change in the non-destructive group. The COMP levels did not change in any of the groups. The aggrecan concentrations were initially highest in the group developing destructions (P << 0.001), whereas no difference between the groups was found regarding levels of COMP or BSP in the first sample.
CONCLUSIONS—A destructive group was characterised by higher initial aggrecan concentrations and rising BSP concentrations in synovial fluid with time. Quantification of cartilage and bone derived macromolecules contributes to the assessment of extent of tissue destruction and may help in the early identification of patients at risk of rapidly progressing destruction.

     

Incidence of hip involvement and need for total hip replacement in rheumatoid arthritis. An eight-year follow-up study

In an 8-year follow-up of a prospective study of recent arthritis, 103 patients were found to have erosive and 97% seropositive rheumatoid arthritis. A 20% incidence of hip joint involvement was observed among them. Moderate radiological changes could be seen in 10%, severe destruction (Larsen 4 or 5) in 3%, and acetabular protrusion in 1% of the patients. It was estimated that the minimum annual need of total hip replacement in rheumatoid arthritis in Finland would be 470. This is about 100 per million in the overall population. At the end of the follow-up the Larsen X-ray index was highly significantly (p less than 0.001), ESR significantly (p less than 0.005), and CRP clearly (p less than 0.03) higher in the 13 patients with radiologically confirmed hip changes than in the 90 without them. Thus their hip destruction is attributable to a more severe disease condition and not to the glucocorticoids administered. Furthermore, HLA-B27 was positive in 69% of the above-mentioned 13 patients compared with 27% of the rest, and this difference (p less than 0.005) may also explain the poor prognosis for true rheumatoid arthritis patients.     

Prosthetic joint infection after total hip or knee arthroplasty in rheumatoid arthritis patients treated with nonbiologic and biologic disease-modifying antirheumatic drugs

The aim of this study was to identify risk factors for acute surgical-site infection (SSI) after total joint arthroplasty in rheumatoid arthritis (RA) patients treated with nonbiologic and biologic disease-modifying antirheumatic drugs (DMARDs). We performed a retrospective study of all consecutive total hip (THA) and total knee (TKA) arthroplasties performed during a 5-year period (THA 81; TKA 339). Multivariate logistic regression analysis was performed to identify SSI risk factors. Of the patients undergoing THA or TKA, 24 cases (5.7%) developed a superficial incisional SSI requiring the use of antibiotics and three cases (0.7%) developed an organ/space SSI necessitating surgical treatment to remove the artificial joint prosthesis. Multivariate logistic regression analysis revealed that the use of biologic DMARDs [P = 0.0007, odds ratio (OR) = 5.69; 95% confidence interval (CI) 2.07–15.61] and longer RA duration (P = 0.0003, OR = 1.09; 95% CI 1.04–1.14) were the only significant risk factors for acute SSI. Furthermore, an analysis that individually evaluated major agents (n > 10) adjusted for disease duration indicated that tumor necrosis factor alpha blockers increased the risk of SSI (infliximab P = 0.001, OR = 9.80, 95% CI 2.41–39.82; etanercept P = 0.0003, OR = 9.16, 95% CI 2.77–30.25). We found that the use of infliximab or etanercept and longer disease duration were associated with an increased risk of acute SSI in RA patients. Prospective studies are thus needed to determine the safety of biologic DMARDs in the perioperative period.     

Physical activity levels after hip and knee joint replacement surgery: an observational study

Clinical Rheumatology - Usual care after hip or knee joint replacement does not adequately address the problem of low physical activity levels. We aimed to determine whether exercise delivered in a...     

Factors influencing surgeons' decisions in the indication for total joint replacement in hip osteoarthritis in real life

OBJECTIVE: To evaluate factors influencing orthopedic surgeons' decision in daily practice to recommend or not recommend total hip arthroplasty (THA) in patients with hip osteoarthritis (OA). METHODS: General practitioners and rheumatologists were asked to prospectively include 1 patient with hip OA for whom a consultation with an orthopedic surgeon was planned to determine whether or not THA was indicated. The following variables were obtained: age, sex, occupational status, body mass index, comorbidities, duration of hip OA, patient's global assessment, Western Ontario and McMaster Universities Osteoarthritis Index pain and functioning subscale scores, New Zealand score, quality of life, and structural parameters on radiographs. The surgeon's decision was obtained by followup questionnaires. Statistical analysis evaluated potential predictors of the surgeon's decision (indication for THA within the next 6 months, yes or no) using univariate and multivariate analysis. RESULTS: A total of 558 patients were included (249 men, 300 women, mean age 68.4 years, mean disease duration 4.9 years). The surgeon's decision, available for 486 patients, was to prescribe THA in 60.7% of patients. On multivariate analysis, the variables related to the surgeon's decision were the presence or absence of severe cardiovascular disease, Short Form 12 physical subscale score, and amount of joint space narrowing. CONCLUSION: While the amount of structural degradation is only slightly or not at all taken into account in numerous criteria and/or recommendations on indications for THA, it is an independent predictor of the surgeon's decision in daily practice. Such a discrepancy should be evaluated and understood in further studies.     

OMERACT/OARSI initiative to define states of severity and indication for joint replacement in hip and knee osteoarthritis

OBJECTIVE: Time to theoretical indication of joint replacement surgery has been proposed as a primary outcome for potential structure-modifying interventions for osteoarthritis (OA). The objectives of this OMERACT/OARSI Working Group were to identify pain, physical function, and structure states that represent the progression from early to late disease for individuals with OA of the hip and knee, and to create a composite measure of these 3 domains to define states of OA severity and a surrogate measure of "need for joint replacement surgery." METHODS: For pain, focus groups and one-on-one interviews were used. For function, Rasch analysis was performed on existing indices the Hip Dysfunction and Osteoarthritis Outcome Score (HOOS) and the Knee injury and Osteoarthritis Outcome Score (KOOS), each of which subsumes the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questions. For structure, a comparison of existing indices (Kellgren-Lawrence, OARSI stages, and joint space width) was performed for the hip and the knee. RESULTS: For pain, key features of pain that are most distressing to people with OA from early to late disease were identified. For function, the reduction of the number of items based on the existing indices continues. For structure, the analysis is also ongoing. CONCLUSION: Preliminary results were presented at OMERACT 8; the final objective will be to combine the 3 domains (pain, function, and structure) and to create a composite index that could define states of severity and "need for total joint replacement," which could be used to evaluate treatment response to disease-modifying drugs in OA clinical trials.