Long-term results of total knee arthroplasty in class 3 and 4 rheumatoid arthritis

Early appearance of radiolucent lines around total knee arthroplasty in rheumatoid arthritis patients. How does it impact the aseptic failure rate and functional outcomes at 13 years of follow-up?

INTRODUCTION

Aseptic total knee arthroplasty (TKA) failure has been associated with radiolucent lines. This study aimed to determine the impact of the early appearance of radiolucent lines (linear images of 1, 2, or >2mm at the cement-bone interface) around the TKA on prosthetic survival and functional outcomes in rheumatoid arthritis (RA) patients during a 2-20 years follow-up.

METHODS

We retrospectively analyzed a consecutive series of RA patients treated with TKA between 2000 and 2011. We comparatively analyzed patients with and without radiolucent lines around implants. Clinical outcomes were assessed with the knee society score (KSS) collected before surgery, at years 2, 5, and 10, and at the last postoperative follow-up. The knee society roentgenographic evaluation system was used to analyze the impact of radiolucent lines around the implants at 1, 2, 5, and more than ten years of follow-up. The reoperation and prosthetic survival rates were calculated at the end of the follow-up.

RESULTS

The study series included 72 TKAs with a median follow-up of 13.2 years (range: 4.0-21.0), of which 16 (22.2%) had radiolucent lines. We did not observe aseptic failure, and prosthetic survival at the end of the study was 94.4% (n=68). The KSS improved significantly (p<0.001) between preoperative values at 2, 5, and 10 years and the end of follow-up, with no differences between patients with and without radiolucent lines.

CONCLUSIONS

Our study demonstrates that the early appearance of radiolucent lines around a TKA in RA patients does not significantly impact prosthetic survival or long-term functional outcomes at 13 years of follow-up.

Early appearance of radiolucent lines around total knee arthroplasty in rheumatoid arthritis patients. How does it impact the aseptic failure rate and functional outcomes at 13 years of follow-up?

INTRODUCTION

Aseptic total knee arthroplasty (TKA) failure has been associated with radiolucent lines. This study aimed to determine the impact of the early appearance of radiolucent lines (linear images of 1, 2, or > 2mm at the cement-bone interface) around the TKA on prosthetic survival and functional outcomes in rheumatoid arthritis (RA) patients during a 2-20 years follow-up.

METHODS

We retrospectively analyzed a consecutive series of RA patients treated with TKA between 2000 and 2011. We comparatively analyzed patients with and without radiolucent lines around implants. Clinical outcomes were assessed with the knee society score (KSS) collected before surgery, at years 2, 5, and 10, and at the last postoperative follow-up. The knee society roentgenographic evaluation system was used to analyze the impact of radiolucent lines around the implants at 1, 2, 5, and more than ten years of follow-up. The reoperation and prosthetic survival rates were calculated at the end of the follow-up.

RESULTS

The study series included 72 TKAs with a median follow-up of 13.2 years (range: 4.0-21.0), of which 16 (22.2%) had radiolucent lines. We did not observe aseptic failure, and prosthetic survival at the end of the study was 94.4% (n=68). The KSS improved significantly (p<0.001) between preoperative values at 2, 5, and 10 years and the end of follow-up, with no differences between patients with and without radiolucent lines.

CONCLUSIONS

Our study demonstrates that the early appearance of radiolucent lines around a TKA in RA patients does not significantly impact prosthetic survival or long-term functional outcomes at 13 years of follow-up.

Inferior outcomes of primary total knee arthroplasty in patients with rheumatoid arthritis compared to patients with osteoarthritis

PURPOSE

The purpose of this study was to compare the functional outcomes, activity levels, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) with those in patients with osteoarthritis (OA) over a minimum 10-year follow-up period.

METHODS

Between January 2007 and December 2009, 90 TKAs performed in 57 patients with RA (RA group) were retrospectively reviewed and matched with a control group of 180 TKAs performed in 114 patients with OA. The functional outcomes (Knee Society Score), activity levels (Koval grade), mortalities, implant survival rates, and complications were compared between the two groups with a minimum 10-year follow-up period. The mean follow-up periods were 12.3 years in the RA group and 12.6 years in the OA group.

RESULTS

The mean Knee Society knee scores in the RA and OA groups improved from 37.7 ± 5.4 to 38.2 ± 5.3 preoperatively to 72.9 ± 22.8 to 83.1 ± 11.0 points, respectively, at the final follow-up (p < 0.05). At the final follow-up, 38 of 48 (79.2%) in the RA group and 105 of 109 (96.3%) in the OA group (p < 0.05) were outdoor ambulatory patients. The cumulative mortality rates in the RA and OA groups were 15.8% (9/57) and 4.4% (5/114) (p < 0.05) at the final follow-up, respectively. Kaplan-Meier survivorship analysis with revision of either component as an endpoint in the RA and OA groups estimated 94.4% and 98.3% chance of survival for 10 years, respectively.

CONCLUSION

TKA in patients with RA had worse functional outcomes and higher mortality over a minimum 10-year follow-up period, compared with TKA in patients with OA.

LEVEL OF EVIDENCE

IV.

Changes in perioperative C-reactive protein levels in patients with rheumatoid arthritis undergoing total knee arthroplasty in the biologic era

This study aimed to investigate changes in and factors associated with perioperative serum C-reactive protein (CRP) levels in rheumatoid arthritis (RA) patients undergoing total knee arthroplasty (TKA) in the biologic era. A total of 173 patients (228 knees) with RA underwent elective primary TKA at our institute between January 1, 2006 and December 31, 2018. Of these, 214 cases among 161 patients were examined in this retrospective study after excluding 3cases among 3 patients who developed postoperative complications and 11 cases among 9 patients who were treated with tocilizumab. Factors associated with changes in CRP levels between baseline (preoperative) and day 7 after TKA [ΔCRP (0-7days)] were assessed by multiple regression analysis. Median (interquartile range) CRP levels were 0.69 (0.21, 1.82) mg/dl preoperatively, 5.66 (4.21, 7.61) mg/dl on postoperative day 1, 12.75 (9.79, 16.74) mg/dl on postoperative days 3-4, 3.26 (2.21, 4.85) mg/dl on postoperative day 7, and 0.87 (0.45, 1.81) mg/dl on postoperative day 14. Multivariate regression analysis revealed that body mass index ≥25 [partial regression coefficient (B)=1.03, P=0.012] and use of glucocorticoids (B=-0.86, P=0.017) were independently associated with ΔCRP (0-7days), whereas use of methotrexate and targeted drug modifying antirheumatic drugs and preoperative CRP levels (an objective biomarker of RA activity) were not. In conclusion, serum CRP levels increased rapidly after TKA and peaked on postoperative days 3-4, followed by a return to preoperative levels by postoperative day 14 in patients with RA. Obesity and the use of glucocorticoids were independently associated with changes in CRP levels.

Long-term outcomes and duration of outdoor ambulation following primary total knee arthroplasty in patients with rheumatoid arthritis

BACKGROUND

The medical treatment of rheumatoid arthritis (RA) has made remarkable progress with the introduction of methotrexate and biological agents. However, there have been few reports of long-term results of total knee arthroplasty (TKA) for RA since the introduction of these drugs. Ambulation is an important form of exercise for maintaining health. We investigated the long-term outcomes and the ability to walk outdoors following TKA in patients with RA.

METHODS

We retrospectively reviewed 142 patients with RA (201 knees) who had undergone primary TKA. The mean follow-up was 10.6 years.

RESULTS

Markers of RA disease activity all improved significantly postoperatively. Mean Japanese Orthopedic Association scores improved from 49.3 points before surgery to 81.8 at follow-up. The mean maximum flexion angle improved from 107.8° to 112.9°. The causes of TKA revision comprised 2 mechanical loosening, 1 late infection, and 1 fracture of the femoral condyle. The survival rate of TKA was 96.6% at 15 years. Fifty-five patients were not able to walk outdoors. The rate of inability to ambulate outdoors was 38.3 per 1000 person-years. The survival rate of ability to ambulate outdoors were 48.8% at 15 years. Preoperative advanced age, low body weight, steroid use and non-use of biologics were identified as risk factors for inability to ambulate outdoors.

CONCLUSIONS

Although the cumulative survival rate of TKA implants was as good as 96.6% in 15 years, the cumulative rate of ability to ambulate outdoors was only 48.8%. The reason for the inability to walk outdoors was thought to be mainly due to deterioration of RA, comorbidity or muscular weakness associated with aging, rather than knee dysfunction.

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.

Functional outcome of total knee replacement for inflammatory arthritis of knee

Introduction:

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disorder that involves symmetrical small and large joints. Despite DMARDs, biological agents and anti-inflammatory agents, severe damage to the joint cartilage occurs, mainly due to the growing synovium. Total knee replacement in RA has been an enormous boon to those who are suffering from pain and deformity because of severe restriction of knee joint movement.

Objectives:

To evaluate the clinical, functional and radiological outcomes after TKR for inflammatory arthropathy and to identify potential factors that affect the functional outcome after TKR for Rheumatoid Arthritis.

Materials and Methods:

Patients who underwent total knee arthroplasty for rheumatoid arthritis during the period 2011–2018 were recruited for the study after informed consent. The American Knee Society scores and functional scores were used for the functional outcome and assessment. Preoperative scores were obtained from previous medical records. Paired t test was done to determine the significance in changes between the preoperative and postoperative scores. Bivariate analysis using Spearman correlation and logistic regression analysis was performed to assess the influence of various factors on the postoperative knee scores.

Results:

The average age of patients at the time of TKR was 54 years, all were in stage IV disease, and the majority were women (n = 20). The significant improvement (p = 0.000) was observed between the preoperative (57.3) and postoperative (97.4) Knee Society scores, as well as improvement in functional scores from 36.3 preoperative to 85.2 points postoperatively after TKR. Steroid usage had a significant positive correlation. The duration of disease and involvement of the other joint had a significant negative correlation to postoperative functional scores.

Conclusion:

Total Knee Replacement has been proved as one of the most successful surgical interventions for reducing pain and enhancing physical function in inflammatory arthritis patients.

Total Knee Arthroplasty in Ochronosis Arthropathy: A Case Report and Systematic Review

INTRODUCTION

Ochronosis arthropathy (OcA) is a rare condition which may be treated with total knee arthroplasty (TKA) at the end stage. The condition is often discovered only intraoperatively and the ideal choice of TKA is unknown.

CASE PRESENTATION

A 54-year-old male with worsening chronic bilateral mechanical knee pain had failed conservative therapy. Posterior stabilised (PS), cemented TKA and patella resurfacing was performed. Intraoperatively, collagenous structures such as the menisci and cartilage were noted to be black. Histological examination showed deposition of large amorphous brown material suggestive of ochronosis. He recovered well and underwent TKA of the contralateral knee the following year. At 2 years postindex TKA, his outcome scores improved and he was satisfied.

DISCUSSION AND CONCLUSION

With increasing TKA performed worldwide, a surgeon may eventually be surprised by the above findings once in their lifetime. However, OcA may be considered a likely diagnosis and it is safe to proceed with TKA. There is no particular TKA design that proved to be superior in our systematic review of 19 publications regarding TKA as all reported good outcomes. However, as the pathogenesis of OcA appears to be inflammatory in nature, we suggest using cemented PS TKA with resurfacing of the patella.

Cementless femoral components in bicondylar hybrid knee arthroplasty in patients with rheumatoid arthritis: A 10-year survivorship analysis

BACKGROUND

Total knee arthroplasty (TKA) has been established as a successful surgical treatment in the late stages of rheumatoid joint destruction. The purpose of this study was to review the clinical outcome and survivorship in rheumatoid arthritis (RA) patients undergoing TKA in hybrid technique with a cementless fixation of the femoral component.

METHODS

We analysed retrospectively 66 RA patients who underwent 72 TKAs (P.F.C. Sigma®). Mean follow-up time was 124 ± 41 months. To evaluate postoperative clinical outcome, knee injury and osteoarthritis outcome score (KOOS) and Oxford knee score (OKS) were assessed. Kaplan-Meier analysis was used to calculate survivorship. The primary outcome was revision for any reason.

RESULTS

Thirty-four patients (36 knees) died and two patients (2 knees) were lost to follow-up. Three patients (four knees) did not agree to participate. Twenty-seven patients (30 knees) were available for assessing clinical scores. The average scores were 85 ± 14 for KOOS and 34 ± 10 for OKS. In three patients (three knees), revision was necessary, including restricted range of motion ( n = 1), instability ( n = 1), and infection ( n = 1). There were no cases of loosening in this cohort study. The survival rates were 100% at 5 years, 97.1% at 10 years (95% CI 89.0-99.2%) and 95.6% at 15 years (95% CI 86.9-98.5%).

CONCLUSIONS

This study confirms that excellent clinical results and a good 10-year survivorship can be obtained with hybrid fixation technique in TKA in the unique population of RA patients.

Outcomes of Cementless Total Knee Arthroplasty in Patients With Rheumatoid Arthritis

The objective of this study was to evaluate implant survivorship, clinical outcomes, postoperative complications, and radiographic outcomes of cementless total knee arthroplasty (TKA) in patients who have rheumatoid arthritis (RA). Patients who underwent a primary cementless posterior-stabilized TKA and who had RA were reviewed. A total of 126 TKAs in 122 patients who had a mean follow-up of 4 years were analyzed. Implant survivorship was calculated. Postoperative clinical and radiographic follow-up was performed at approximately 6 weeks and 3 months and then annually. Changes in range of motion and Knee Society scores were noted. Radiographic evaluation was conducted as part of the follow-up process. Implant survivorship was 99.2%, with 1 aseptic failure. At final follow-up, mean extension and flexion were 2° (range, 0°-10°) and 124° (range, 95°-140°), respectively. Mean Knee Society pain and function scores were 92 points (range, 80-100 points) and 84 points (range, 70-90 points), respectively. There were no surgical complications. No progressive radiolucencies, loosening, or subsidence were noted except from the single aseptic failure reported. This study reports excellent survivorship and clinical and radiographic outcomes of cementless TKAs in RA patients. Although the decision regarding whether to use cemented or cementless TKAs in these patients should be based on surgeon experience and patient characteristics, the recent advances in implant fixation of cementless TKAs indicate no salient contraindications for RA patients. [Orthopedics. 2018; 41(2):103-106.].

Skeletal complications of rheumatoid arthritis

Rheumatoid arthritis (RA) is associated with local and systemic inflammation that induces many changes in the skeletal health. Locally, periarticular bone loss and juxta-articular bone erosions may occur while joint ankylosis, generalized bone loss, osteoporosis, and fractures may develop secondary to inflammation. The aim of this narrative review is to summarize the clinical evidence for abnormal skeletal health in RA, the effects of disease modifying anti-rheumatic drugs (DMARDS) on bone health, and the effects of drugs for the prevention or treatment of osteoporosis in the RA population.

Total knee arthroplasty for rheumatoid arthritis

Abstract Total knee arthroplasty is a proven technique for the management of deformity and unremitting pain in the rheumatoid arthritic knee. Many important considerations must be taken into account in order to maximize the results of total knee replacement in this challenging patient population.

The long-term outcome of uncemented Low Contact Stress total knee replacement in patients with rheumatoid arthritis

We reviewed the long-term clinical and radiological results of 63 uncemented Low Contact Stress (LCS) total knee replacements (TKRs) in 47 patients with rheumatoid arthritis. The mean age of the patients at the time of surgery was 69 years (53 to 81). At a mean follow-up of 22 years (20 to 25), 12 patients were alive (17 TKRs), 27 had died (36 TKRs), and eight (ten TKRs) were lost to follow-up.

Revision was necessary in seven patients (seven TKRs, 11.1%) at a mean of 12.1 years (0 to 19) after surgery. In the surviving ten patients who had not undergone revision (15 TKRs), the mean Oxford knee score was 30.2 (16 to 41) at a mean follow-up of 19.5 years (15 to 24.7) and mean active flexion was 105° (90° to 150°). The survival rate was 88.9% at 20 years (56 of 63) and the Kaplan–Meier survival estimate, without revision, was 80.2% (95% confidence interval 37 to 100) at 25 years.

Cite this article: Bone Joint J 2013;95-B:1497–9.

Does the method of component fixation influence clinical outcomes after total knee replacement? A systematic literature review

A systematic literature review was conducted to identify the best available evidence describing the differences in clinical outcome associated with the different methods of total knee replacement (TKR) fixation. Randomized trials published between 1980 and January 2011 comparing differences in clinical outcome scores between groups allocated to either cemented or uncemented fixation for TKR were included. Nine of the 11 studies included in the review reported no significant differences in clinical outcomes between groups with either cemented or uncemented prosthesis components. Critical appraisal of methodological bias revealed consistent shortcomings in study design and execution. It is apparent that more rigorous studies with longer follow-up periods are required to verify which method of fixation may be preferable in enhancing clinical outcomes.

Effects of a less-invasive surgical technique on cement mantle quality in total knee arthroplasty

The purpose of this study was to assess the effects of a less-invasive midvastus exposure during total knee arthroplasty (TKA) on cement mantle grade compared with a standard parapatellar arthrotomy and standard TKA. Fifty consecutive cemented minimally invasive TKAs using a midvastus approach, patellar subluxation without eversion, and less-invasive instrumentation were compared radiographically with a control cohort of 50 consecutive cemented standard TKAs. To eliminate patient selection bias, the standard cohort included consecutive surgeries completed before 2004, prior to the advent of minimally invasive techniques in TKA. Analog supine anteroposterior and lateral radiographs were evaluated using Ewald's criteria. Lucent lines, cement voids, and cement debris were recorded for each group. Radiographic analysis revealed compromised femoral component cement mantle grades in the minimally invasive group. The number of anterior femoral cement voids (zone 1) was significantly higher in the minimally invasive group, and peripatellar and tibial cement debris was also more common in the minimally invasive group. Based on these findings, the midvastus approach compromises the surgeon's ability to duplicate a consistent femoral cement mantle obtained using a standard exposure.

Lower limb joint replacement in rheumatoid arthritis

Introduction

There is limited literature regarding the peri-operative and surgical management of patients with rheumatoid disease undergoing lower limb arthroplasty. This review article summarises factors involved in the peri-operative management of major lower limb arthroplasty surgery for patients with rheumatoid arthritis.

Methods

We performed a search of the medical literature, using the PubMed search engine (http://www.pubmed.gov). We used the following terms: ‘rheumatoid’ ‘replacement’ ‘arthroplasty’ and ‘outcome’.

Findings

The patient should be optimised pre-operatively using a multidisciplinary approach. The continued use of methotrexate does not increase infection risk, and aids recovery. Biologic agents should be stopped pre-operatively due the increased infection rate. Patients should be made aware of the increased risk of infection and periprosthetic fracture rates associated with their disease. The surgical sequence is commonly hip, knee and then ankle. Cemented total hip replacement (THR) and total knee replacement (TKR) have superior survival rates over uncemented components. The evidence is not clear regarding a cruciate sacrificing versus retaining in TKR, but a cruciate sacrificing component limits the risk early instability and potential revision. Patella resurfacing as part of a TKR is associated with improved outcomes. The results of total ankle replacement remain inferior to THR and TKR. RA patients achieve equivalent pain relief, but their rehabilitation is slower and their functional outcome is not as good. However, the key to managing these complicated patients is to work as part of a multidisciplinary team to optimise their outcome.

Total Knee Arthroplasty in Rheumatoid Arthritis

The course of rheumatoid arthritis varies from mild disease to severe joint destructive variant that progresses rapidly, eventually leading to unremitting pain and joint deformity. In advanced disease, total knee arthroplasty has proven to be the most successful intervention that reduces knee pain and improves physical function in rheumatoid arthritis patients. However, as rheumatoid arthritis patients carry additional potential for late complications, many important considerations regarding preoperative evaluation and surgical technique must be taken into account in order to improve the results of total knee arthroplasty in this subgroup of patients.

Clinical results of Hi-tech Knee II total knee arthroplasty in patients with rheumatoid athritis: 5- to 12-year follow-up

BACKGROUND

Total knee arthroplasty (TKA) is a common form of treatment to relieve pain and improve function in cases of rheumatoid arthritis (RA). Good clinical outcomes have been reported with a variety of TKA prostheses. The cementless Hi-Tech Knee II cruciate-retaining (CR)-type prosthesis, which has 6 fins at the anterior of the femoral component, posterior cruciate ligament (PCL) retention, flat-on-flat surface component geometry, all-polyethylene patella, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra high molecular weight polyethylene (UHMWPE), is appropriate for TKA in the Japanese knee.The present study was performed to evaluate the clinical results of primary TKA in RA using the cementless Hi-Tech Knee II CR-type prosthesis.

MATERIALS AND METHODS

We performed 32 consecutive primary TKAs using cementless Hi-Tech Knee II CR-type prosthesis in 31 RA patients. The average follow-up period was 8 years 3 months. Clinical evaluations were performed according to the American Knee Society (KS) system, knee score, function score, radiographic evaluation, and complications.

RESULTS

The mean postoperative maximum flexion angle was 115.6°, and the KS knee score and function score improved to 88 and 70 after surgery, respectively. Complications, such as infection, occurred in 1 patient and revision surgery was performed. There were no cases of loosening in this cohort, and prosthesis survival rate was 96.9% at 12 years postoperatively.

CONCLUSION

These results suggest that TKA using the cementless Hi-Tech Knee II CR-type prosthesis is a very effective form of treatment in RA patients at 5 to 12 years postoperatively. Further long-term follow-up studies are required to determine the ultimate utility of this type of prosthesis.

All-polyethylene tibial components in TKA in rheumatoid arthritis: a 25-year follow-up study

Purpose

There is renewed interest in the all-polyethylene tibial component in total knee arthroplasty (TKA). Long-term results of this prosthesis in rheumatoid arthritis (RA) patients, however, are limited. Therefore, we studied 104 primary cemented all-polyethylene tibial TKA in 80 consecutive RA patients for up to 25 years to determine the long-term survival of all-polyethylene tibial components in patients suffering from end stage RA.

Methods

We estimated revision rates according the revision rate per 100 observed component years used in national joint registries. Kaplan–Meier was used to estimate survival curves.

Results

During the 25-year follow-up, three revisions for tibial component loosening were performed. The mean revision rate of all-polyethylene tibial components with revision for aseptic loosening as the endpoint was 0.09 per 100 observed component years. This corresponds to a revision rate of 0.9% after ten years and 2.25% after 25 years. Survivorship according to Kaplan–Meier was 100% at ten years and 87.5% at 25 years [95% confidence interval (CI) 64.6–100)].

Conclusion

This study shows good long-term results of all-polyethylene tibial TKA in patients with RA. RA patients with multiple-joint inflammation may be less physically active than osteoarthritis patients, resulting in a lower demand on the prosthesis, and these patients may, indeed, be good candidates for all-polyethylene tibial TKA. Our results suggest that all-polyethylene tibial TKA could be a successful and cost-saving treatment for end-stage knee arthritis in RA patients.

Average 10.1-year follow-up of cementless total knee arthroplasty in patients with rheumatoid arthritis

BACKGROUND

Total knee arthroplasty (TKA) using a cemented technique has been recommended in patients with rheumatoid arthritis owing to the initial stability of the fixation and long-term durability of the components; however, similar long-term follow-up results have been reported in patients who have undergone cementless TKA. The purpose of this study was to evaluate the radiologic and clinical outcomes of cementless TKA in patients with rheumatoid arthritis.

METHODS

We enrolled patients undergoing cementless TKA from March 1990 to February 2000. Clinical and radiologic evaluations were performed using the Knee Society clinical rating system and radiographic evaluation and scoring system.

RESULTS

We included the cases of 112 patients who underwent 179 cementless TKA procedures in our analysis. Their mean age was 62.3 years, and the mean follow-up period was 10.1 years. The final survival rate was 0.968 at the 15.5-year follow-up. Regarding radiologic results after surgery, the mean total valgus angle was 6.7°, the mean femoral flexion angle was 97.5° and the mean tibial angle was 89.2° on the anteroposterior radiographs. On the lateral films, the mean femoral flexion angle was 1.6° and the mean tibial angle was 89.2°. At the last follow-up, the mean total valgus angle was 6.5°, the mean femoral flexion angle was 97.4° and the mean tibial angle was 89.1°, as seen on the anteroposterior view. On the lateral views, the mean femoral flexion angle was 1.4° and the mean tibial angle was 89.0°. Regarding the clinical outcome, the mean knee score and function score on the Knee Society clinical rating system were also enhanced from 47.5 and 43.6, respectively, before the operation to 91.2 and 82.3, respectively, at the last follow-up.

CONCLUSION

On radiologic and clinical follow-up of cementless TKA for patients with rheumatoid arthritis, there were no serious complications, and the results of the operation were satisfactory with improvement in range of motion and clinical symptoms.

Revision total knee arthroplasty for aseptic and septic causes in patients with rheumatoid arthritis

Revision total knee arthroplasty in patients with rheumatoid arthritis can be challenging. We asked whether we could confirm previously reported high failure rates following revision total knee arthroplasty in patients with rheumatoid arthritis. We therefore determined the Knee Society knee score and function scores, radiographic evidence of failure, and overall survival of the revision procedure in these patients. We retrospectively reviewed 39 patients with rheumatoid arthritis who underwent 45 TKA revisions from 1994 to 2006. Twenty-seven of the 45 TKA revisions were for mechanical failure of the prosthetic components and 18 for infection. Five of the 27 knees (19%) revised for mechanical failure subsequently failed a second time. Five of the 18 patients who underwent revision for infection died within 6 months and three of the remaining knees failed secondary to reinfection. Excluding the knees that failed, the average Knee Society knee score and function score improved in both subgroups. Two knees had radiographic evidence of nonprogressive tibial radiolucencies. The probability of survival for all knees (revision as the end point) was 76% +/- 9% at 5 years. We confirmed the previously reported high mortality and subsequent failure rates following revision total knee arthroplasty for both mechanical issues and infection in patients with rheumatoid arthritis and emphasize the potential difficulties in treating these patients.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Clinical results of bone ingrowth TKA in patients with rheumatoid arthritis

Patients with rheumatoid arthritis (RA) often are not considered for TKA with bone ingrowth fixation because of poor bone quality, but we asked whether implants with sintered metal bead surfaces could be used to durably fix implants in this group of patients. We prospectively evaluated a consecutive series of 47 patients (64 knees) between January 1, 1994, and December 30, 2001, in two separate medical centers using one TKA system. Standard primary implants were used in all knees except those with major bone defects, and in these patients we used long diaphyseal stems to stabilize the implants. Minimum followup was 61 months (mean +/- standard deviation, 83 +/- 6 months; range, 61-124 months). Survivorship was 98.4% at 10 years postoperatively. No components failed because of loosening. One femoral component was revised for fracture because of a massive intraosseous rheumatoid cyst. No knees had radiographic evidence of migration or widening radiolucent lines. Knee Society clinical, pain, and function scores improved after surgery and were maintained throughout followup. These data suggest bone ingrowth implants can provide durable fixation in patients with RA.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

A comparison of survival of moulded monoblock and modular tibial components of 751 AGC total knee replacements in the treatment of rheumatoid arthritis

We evaluated the survival of moulded monoblock and modular tibial components of the AGC total knee replacement in patients with rheumatoid arthritis. Between 1985 and 1995, 751 knees with this diagnosis were replaced at our institution. A total of 256 tibial components were of the moulded design and 495 of the modular design. The mean follow-up of the moulded subgroup was 9.6 years (0.5 to 14.7), and that of the modular group 7.0 years (0.1 to 14.7). The groups differed significantly from each other in Larsen grade, cementing of components and patellar resurfacing, but no statistically significant difference between the survival of the components was found (Log rank test, p = 0.91). The cumulative success rate of the moulded group was 96.8% (95% confidence interval 93.6% to 98.4%) at five years and 94.4% (95% confidence interval 90.4% to 96.7%) at ten years, and of the modular group 96.2% (95% confidence interval 94% to 97.6%) and 93.6% (95% confidence interval 89.7% to 96%), respectively. Revision was required in 37 total knee replacements, the main causes were infection, pain, loosening of the tibial component and patellar problems. Survival rates for both components were satisfactory.

Modern management of haemophilic arthropathy

Currently available factor concentrates for treatment of patients with haemophilia are virally inactivated or are made by recombinant technology and their broad use in developed nations has resulted in the dramatic elimination of the treatment-related viral illnesses that decimated the haemophilia community in the late 20th century. The major morbidity experienced by patients with haemophilia today is joint disease, a result of repeated bleeding episodes into joint spaces. Although administration of factor concentrates to prevent bleeding has been demonstrated to prevent haemophilic joint disease when applied assiduously, repeated bleeding episodes induce synovitis that is irreversible and may progress despite subsequent prophylaxis. Surgical and nuclear medicine interventions are available to reduce the pain of haemophilic arthropathy and to reduce further bleeding episodes. Patients with high titre inhibitors are at great risk for the development of joint disease and present the greatest therapeutic challenges when joint surgery is needed.

Retention of the patella in total knee arthroplasty for rheumatoid arthritis

AIM

To determine whether retention of the native patella during total knee arthroplasty is appropriate in patients with rheumatoid arthritis.

METHODS

All patients undergoing total knee arthroplasty with a diagnosis of rheumatoid arthritis were identified between January 1997 and December 2000. Subsequently, each individual underwent both radiological and clinical assessments at a designated follow-up clinic.

RESULTS

A total of 30 total knee arthroplasties were studied in 28 patients. Twenty-six patients (93%) were female with a mean age of 74.7 years (range 60-83 years). The average post-operative interval was 59.4 months (range 46-82 months). All individuals were noted to have satisfactory patellar tracking and bone stock at the time of surgery. No patient subsequently underwent revision surgery during follow-up and no episodes of implant sepsis were identified. The mean Patellar Score at final follow-up was 26.2 (range 22-30) with an average anterior knee pain score of 14.2 (range 10-15). The mean Oxford Knee Score was 18.7 (range 16-23) with a mean pain score component of 5.9. Patients were finally assessed with respect to the Knee Society Score. The mean Knee Score was 83.8 (range 71-96) with a mean Function Score of 79.7 (range 40-90).

CONCLUSION

By retaining the native patella we were still able to obtain highly satisfactory medium-term results in terms of pain relief and function. In addition, the potential complications associated with prosthetic replacement of the patella were avoided.

Revision total knee arthroplasty with the Total Condylar III system in inflammatory arthritis

We report a consecutive series of 16 revision total knee arthroplasties using the Total Condylar III system in 14 patients with inflammatory arthritis which were performed between 1994 and 2000. There were 11 women and three men with a mean age of 59 years (36 to 78). The patients were followed up for 74 months (44 to 122). The mean pre-operative Knee Society score of 37 points (0 to 77) improved to 88 (61 to 100) at follow-up (t-test, p < 0.001) indicating very good overall results. The mean range of flexion improved from 62 degrees (0 degrees to 120 degrees) to 98 degrees (0 degrees to 145 degrees) (t-test, p < 0.05) allowing the patients to stand from a sitting position. The mean Knee Society pain score improved from 22 (10 to 45) to 44 (20 to 50) (t-test, p < 0.05). No knee had definite loosening, although five showed asymptomatic radiolucent lines. Complications were seen in three cases, comprising patellar pain, patellar fracture and infection. These results suggest that the Total Condylar III system can be used successfully in revision total knee arthroplasty in inflammatory arthritis.

Long-term results of the uncemented Low Contact Stress total knee replacement in patients with rheumatoid arthritis

We analysed the long-term clinical and radiological results of 63 uncemented Low Contact Stress total knee replacements in 47 patients with rheumatoid arthritis. At a mean follow-up of 12.9 years (10 to 16), 36 patients (49 knees) were still alive; three patients (five knees) were lost to follow-up. Revision was necessary in three knees (4.8%) and the rate of infection was 3.2%. The mean clinical and functional Knee Society scores were 90 (30 to 98) and 59 (25 to 90), respectively, at final follow-up and the mean active range of movement was 104° (55° to 120°). The survival rate was 94% at 16 years but 85.5% of patients lost to follow-up were considered as failures. Radiological evidence of impending failure was noted in one knee.

Knee and hip arthroplasty infection rates in persons with haemophilia: a 27 year single center experience during the HIV epidemic

Total joint replacement (TJR) is an option for the management of chronic haemophilic arthropathy. Because surgery is technically challenging, there is a high rate of deep prosthetic infections, particularly in human immunodeficiency virus (HIV)-infected individuals. We determined the incidence of deep infection rates following total knee and hip arthroplasties in HIV-seropositive and HIV-seronegative persons with haemophilia. Fifty-one primary joint replacements were performed on 32 patients seen at a regional comprehensive haemophilia care center from 1975 to 2002. Thirty prostheses were placed in patients who were HIV-seropositive prior to surgery (n = 14) or seroconverted later (n = 16). Median age at the time of surgery was 33 years (range: 20-61) among 19 HIV-seropositive patients and 35 years (range: 26-74) among 13 HIV-negative patients. Median duration of follow-up was 83 months (range: 2-323). Rate of primary joint infection per artificial joint-year by HIV status was compared by Poisson regression. Main outcome measures were the incidence of primary replacement joint infections by HIV status. Deep infections developed in five (9.8%) of 51 replacement joints. There were two infections during 204.15 joint-years without HIV infection and three infections during 205.28 joint-years with HIV infection. The incidence rate of joint infection (0.98 vs. 1.46 per 100 joint-years) was not increased with HIV (relative risk, RR: 1.49, 95% CI: 0.25-8.93, P = 0.66). We conclude that HIV infection is not a contraindication to knee or hip replacement arthroplasty in the appropriate clinical setting.

Revision surgery for patellar dislocation after primary total knee arthroplasty

This study evaluated risk factors for patellar dislocation after primary total knee arthroplasty and determined functional outcomes in patients following revision. Thirty-nine knees in 39 patients averaging 68 years (range, 27-91 years) at the time of revision were evaluated at a mean of 3.2 years (range, 2-7 years). Mean Knee Society and Function scores significantly improved from 34 and 35 to 77 and 54, respectively. Patellar dislocation most commonly resulted from errors in technique such as soft-tissue imbalance and malaligned components that led to poor tracking of the patella. Patellar tracking only improved after soft-tissue realignment in combination with revision of malaligned or loose components. Although revision significantly improved active knee extension and Knee Scores, two thirds of the patients had residual disabilities and pain.

Long-term followup of posterior-cruciate-retaining TKR in patients with rheumatoid arthritis

A consecutive series of 220 primary posterior-cruciate ligament-retaining total knee replacements were done in 148 patients with rheumatoid arthritis. From this group, 212 total knee replacements (141 patients) were followed up for an average of 10 years. Average knee scores at 5, 10, 15, and 20 years after operation improved to 86, 83, 88, and 89, respectively, and average function scores improved to 70, 72, 64, and 88, respectively. Five knees (2.4%) were revised for deep infection. Posterior instability, recurvaum, or mediolateral instability, combined or otherwise, occurred in 15% (32 knees; in 31 patients). Three tibial components (1.4%) were revised: one for suspected aseptic loosening and two for instability. Excluding infections and failed metal-backed patellas, Kaplan-Meier survival rates were 99.5%, 97.9%, and 96.5%, respectively. Favorable long-term results may be achieved with posterior-cruciate ligament-retaining total knee replacements in patients with rheumatoid arthritis. Concern remains, however, about rotational instability in certain cases associated with preoperative genu-valgum and ipsilateral planovalgus deformity.

Posterior cruciate ligament-substituting total knee arthroplasty in young rheumatoid patients with advanced knee involvement

The integrity and strength of the posterior cruciate ligament (PCL) in the rheumatoid knee are known to be suboptimal. However, the results of PCL-substituting total knee arthroplasty in rheumatoid patients are not well documented. We reviewed 86 PCL-substituting total knee arthroplasties in 52 rheumatoid patients with grade IV or V radiographic disease. The mean age at surgery was 41.9 years. All patients underwent follow-up evaluation for an average of 7.8 years. Revision was performed for 1 knee because of aseptic loosening of the tibial component, and for 3 knees because of deep infection. An isolated insert exchange was performed on one knee. Using revision of any component for aseptic loosening or radiographic loosening as the end point, the mean 10-year survival rate was 94.0%.

15-year follow-up study of total knee arthroplasty in patients with rheumatoid arthritis

In 25 patients with rheumatoid arthritis, 36 cases of cemented Kinematic total knee arthroplasty were reviewed clinically and radiographically at 13 to 19 years after surgery. The mean age at the time of surgery was 51.6 +/- 8.9 years. According to the follow-up results evaluated with the Hospital for Special Surgery knee scoring system, 28 knees (77.7%) were classified as good or excellent. The mean flexion angle at follow-up evaluation was 99 degrees +/- 24 degrees (10 degrees -140 degrees ). At the tibial or femoral bone-cement interfaces, a radiolucent line was seen in 10 of 36 knees (27.8%) at follow-up evaluation. The survival rate of prostheses with revision as the endpoint was estimated to be 93.7% at 15 years. Kinematic total knee arthroplasty in rheumatoid arthritis patients provided a good long-term outcome.

Total knee arthroplasty in young patients with juvenile rheumatoid arthritis

BACKGROUND

Juvenile rheumatoid arthritis is a disabling and destructive condition that commonly affects the knee during childhood. Total knee arthroplasty occasionally may be necessary for the treatment of end-stage disabling arthritis of the knee in young patients. There is a paucity of available data on the results of total knee arthroplasty in adolescents. We report our experience with total knee arthroplasty in patients under the age of twenty years who had juvenile rheumatoid arthritis.

MATERIALS AND METHODS

We reviewed the results of twenty-five consecutive total knee arthroplasties that had been performed at our institution between 1982 to 1997 in thirteen patients (mean age, seventeen years) with juvenile rheumatoid arthritis. The average duration of clinical follow-up was 10.7 years, and the average duration of radiographic follow-up was 6.5 years.

RESULTS

The mean Knee Society pain score improved markedly from 27.6 to 88.3 points, and the mean Knee Society function score improved modestly from 14.8 to 39.2 points. There was a slight improvement in the range of motion. Symptomatic and progressive radiolucent lines were noted in two knees, one of which was revised. Two knees (one patient) required exchange of the polyethylene liner at thirteen years. There were four additional reoperations, including manipulation under general anesthesia (two knees in one patient), lysis of adhesions (one knee), and extensor mechanism realignment (one knee).

CONCLUSIONS

Despite a substantial number of postoperative complications, total knee arthroplasty provided excellent relief of pain and improvement in function in this group of adolescent patients with juvenile rheumatoid arthritis.

Enhancement of bone growth in titanium fiber mesh by surface modification with hydrogen peroxide solution containing tantalum chloride

A tight fixation between bone and implant materials is of great importance for a successful outcome of procedures such as total knee arthroplasty (TKA) and total hip arthroplasty (THA). Surface modification of titanium metal and titanium alloy is one of the attractive methods to improve the biological affinity of orthopedic prostheses. Recent studies reported that titanium substrates were provided with bone-bonding ability, that is, osteoconductivity, through a chemical treatment with hydrogen peroxide solution containing tantalum chloride. The present study investigated the histological and mechanical effects of such treatment of the surface of titanium fiber mesh. Titanium alloy rods of 7.6 x 7.6 x 20 mm that had a titanium fiber mesh of 250 microm were implanted bilaterally into the distal aspect of the femur of adult beagle dogs. At 3, 5, and 8 weeks after implantation, the rods were removed to examine their bonding strength and histological compatibility with bone. Bonding strength was evaluated by the pull-out test. The bonding strength of the treated specimen with bone increased with time, and was faster than that of untreated specimens. At 8 weeks postoperative, the bonding strength of both the treated and untreated specimens became almost equal. The amount of newly formed bone on and in the titanium fiber mesh was significantly increased by the chemical treatment (p<0.05). The rate of bone formation in the fiber mesh was accelerated after chemical treatment. These results indicated that the surface treatment enhanced bone formation in the initial stage thank to the osteoconductive property of the titanium fiber mesh conferred by the chemical treatment so that faster bonding strength was achieved. Surface treatment providing titanium mesh with osteoconductivity has the advantages of the fast healing and tight bonding for prostheses in TKA and THA.

An algorithm for the posterior cruciate ligament in total knee arthroplasty

The fate of the posterior cruciate ligament in primary total knee arthroplasty is controversial. An algorithmic approach is presented that is based on pathologic criteria for evaluating and treating patients with primary total knee arthroplasty that will aid in the posterior cruciate ligament decision-making process, producing more predictable procedures and outcomes. A consecutive series of the first 120 patients (171 knees) who had primary posterior cruciate-retaining arthroplasty and the first 120 patients (180 knees) who had primary posterior-stabilized arthroplasty with a minimum 5-year followup in which the Maxim Complete Total Knee System and the algorithmic approach were used were compared. No statistically significant differences in outcome between the groups were observed. Among the patients who had posterior cruciate-retaining arthroplasty, no revisions attributable to aseptic loosening have been reported at an average followup of 6.39 years. The average followup Knee Society total score was 162.16 points, with 91 (54.8%) knees having excellent outcome ratings. No revisions attributable to aseptic loosening have been reported among the patients who had posterior-stabilized arthroplasty at an average followup of 5.98 years. The average followup Knee Society total score was 158.05 points, with excellent outcome ratings reported in 96 (54.9%) knees. The use of a standardized algorithm has streamlined the treatment of patients having primary total knee arthroplasty, consistently providing excellent clinical results when either retaining or sacrificing the posterior cruciate ligament.

Results at 11.5 years of a series of 376 posterior stabilized HLS1 total knee replacements. Survivorship analysis, and risk factors for failure

Of 376 cemented posterior stabilized HLS1 TKRs inserted in 329 patients (mean age 70) between 1984 and 1988, information was available on 306 (81.4%) at the third follow-up in 1998: 118 patients deceased; 163 followed up clinically (Knee Society score) and radiographically; 25 revised (15 infections; 10 mechanical failures). At a mean follow-up of 11.5 years, the mean pain score was 43/50, and the mean ROM score 21/25 (both unchanged since 1989). The function score had declined linearly, from 70/100 in 1989 to 60/100 in 1998. Forty percent had tibial radiolucencies correlating with the extent of preoperative bone wear. Polyethylene wear (seen in 35% of knees) was always < 3 mm. The implant survival rate (infections included) was 93.7% (+/- 1.4%) after 10 years. All the mechanical failures were in advanced-OA patients with ACL-deficient knees and major bony deficiencies.

Total condylar knee replacement: a 20-year followup study

Between 1976 and 1979, 220 total knee replacements were done on 164 patients using the Total Condylar Knee replacement. The diagnosis was rheumatoid arthritis in 111 knees and osteoarthritis in 109 knees. Patients with 157 knees are known to have died as of December 1998, leaving 63 knees in patients who are still alive. Twelve patients with 18 knees were lost to followup. The average 20-year followup data (range, 18-22 years) are presented for 45 knees in 30 patients using Knee Society evaluations. The average Knee Society clinical score for the surviving patients was 88 points, and the average functional score was 58 points. The radiographic followup averaged 19 years. The average overall alignment was 3 degrees valgus. Femoral lucencies were present in 17 of 40 adequate lateral views, most commonly about the anterior and posterior surfaces. Two femoral components were loose. Twenty-two tibial components had radiolucencies; four radiolucencies were circumferential. The remaining 41 knees retained a well-fixed cemented central peg despite proximal interface lucencies. From the group of 220 knees, 14 revisions have been done at an average of 11.4 years postoperative. Two knee replacements were revised for isolated tibial loosening, whereas one knee replacement had isolated femoral loosening. Three knee replacements were revised for loosening of both components, and one was revised for isolated patellar loosening. Four patients had sepsis develop; three of these four patients were treated with two-stage revision, and one underwent fusion. Three patients were treated for supracondylar fractures. The Total Condylar Knee replacement maintains excellent durability at 20-years followup.

Infections in systemic lupus erythematosus and rheumatoid arthritis

Patients with systemic lupus erythematosus have a higher infection rate than the general population. It is estimated that at least 50% of them will suffer a severe infectious episode during the course of the disease. Improvements in the control of the disease are discussed in this article.

Posterior cruciate-sacrificing versus posterior cruciate-substituting total knee arthroplasty: a study of clinical and functional outcomes in matched patients

Since the introduction of the Total Condylar Prosthesis (TCP) in 1974, concomitant improvements in surgical technique and prosthetic design have occurred. The individual effects of each of these variables have not been investigated, however. This study evaluates 2 different knee designs using the same operative technique by a single surgeon. All primary total knee arthroplasties performed between 1986 and 1989 were entered into a database of 2 cohorts, TCP and Press Fit Condylar (PFC) knees, matched for age, gender, body weight, and diagnosis. Follow-up data within 12 months of each other were used, evaluating patients clinically and using a self-administered questionnaire. In each cohort, 74 knees were matched by these criteria. Follow-up time was 4.04 and 4.45 years for the TCP and PFC cohorts. Range of motion averaged 107 degrees and 112 degrees for the TCP and PFC cohorts. This difference was statistically significant. Total knee score and functional score improved significantly. Anterior knee pain was present in 9 TCP and 3 PFC knees. Lateral release was performed in 30 TCP and 18 PFC knees. The PFC showed an advantage in ROM, stair function, anterior knee pain, and use of lateral release. Both designs showed comparable pain relief and walking ability.

The knee joint in rheumatoid arthritis

Rheumatoid arthritis may present in the knee within a wide spectrum of manifestations. Disease progression, treatment protocols, surgical treatments and the possible complications of these treatments differ distinctly from those of osteoarthritis.

Total knee arthroplasty in patients with rheumatoid arthritis. An overview

Total knee arthroplasty in patients with rheumatoid arthritis presents several unique challenges. Patients with rheumatoid arthritis often have additional medical, anesthetic, and global musculoskeletal problems that are not present in the patient with osteoarthritis. In terms of the knee, these patients usually have osteopenia and may present with an array of bone and soft tissue deformities, each of which can impact the initial success and long term durability of a total knee replacement. Despite these potential difficulties, the early and long term results of total knee arthroplasty in patients with rheumatoid arthritis have proven to be excellent.

Total knee arthroplasty with retention of both cruciate ligaments. A nine to eleven-year follow-up study

BACKGROUND

Although many early designs of total knee arthroplasty allowed the retention of both cruciate ligaments, in most current designs of knee replacement systems, either both cruciate ligaments are removed or the posterior cruciate ligament alone is retained. This report is a review of a series of total knee arthroplasties in which both cruciate ligaments were retained.

METHODS

The results of 163 total knee arthroplasties (130 patients) in which both cruciate ligaments were retained were assessed prospectively. One hundred and seven knees (eighty-nine patients) were followed for an average of ten years. There were thirty-four men and ninety-six women, and the average age at the time of the index arthroplasty was sixty-seven years (range, forty-two to eighty-four years). The diagnosis was osteoarthritis in 122 (75 percent) of the knees and rheumatoid arthritis in forty-one (25 percent). Twenty-six knees had a valgus deformity, 109 had a varus deformity, and twenty-eight had a normal alignment of 5 to 10 degrees of valgus. The anterior cruciate ligament was relatively normal in ninety-six knees and was partly degenerated in sixty-seven knees. With use of the rating system of the Knee Society, all 163 knees were prospectively evaluated at yearly intervals; fifty-six of these knees (in forty-one patients) were followed in this manner until the patient died or was lost to follow-up.

RESULTS

One hundred and four (97 percent) of the 107 knees available for study at an average of ten years had an excellent or good result. At the time of the latest follow-up, pain was adequately relieved in ninety-seven knees (91 percent) and the average range of flexion was 107+/-12.6 degrees (range, 65 to 135 degrees). Ninety-five knees (89 percent) had normal anteroposterior stability (less than five millimeters of movement in this plane), and twelve knees (11 percent) had five to ten millimeters of movement as demonstrated by the drawer sign. Ninety-six knees (90 percent) had normal mediolateral stability, and eleven (10 percent) had 5 to 10 degrees of laxity. Ninety-four knees (88 percent) had valgus alignment of 5 to 10 degrees. The average knee score was 91+/-8.4 points (range, 54 to 100 points), and the average functional score was 82+/-21 (range, 10 to 100 points). The survival rate at ten years, with revision as the end point, was 95+/-2.0 percent. Seven (4 percent) of the 163 knees in this series were revised. There were no revisions for patellar problems or aseptic loosening of the tibial component.

CONCLUSIONS

The good anteroposterior stability in this series after an average follow-up period of ten years indicates that both the anterior and the posterior cruciate ligaments, even when partly degenerated, remain functional when they are preserved in a total knee arthroplasty.

The long-term outcomes of rheumatoid arthritis: a 23-year prospective, longitudinal study of total joint replacement and its predictors in 1,600 patients with rheumatoid arthritis

OBJECTIVE

Although total joint arthroplasty (TJA) is a common procedure and an important outcome in rheumatoid arthritis (RA), little is known about its prevalence, failure rate, or predictors over the course of the illness. The current study evaluated these factors in 1,600 consecutive RA patients seen during a period of observation that extended 23 years.

METHODS

Beginning in 1974, data from 34,040 RA patient visits were entered prospectively into a computer databank. Data consisted of laboratory, radiographic, physical examination, and self-report questionnaires. At each assessment, we also noted a complete surgical history. Patients were also followed up by questionnaires that were mailed at 6-month intervals.

RESULTS

Kaplan-Meier life-table estimates indicated that 25% of RA patients will undergo total joint arthroplasty (TJA) within 21.8 years of disease onset. For patients with 1 TJA, 25% had a TJA in a different joint within 0.92 years and 50% within 7.0 years. Ten years after TJA, approximately 6% of implanted knees and 4% of implanted hips had been replaced with a second TJA, and 12% and 13% of the joints had either a second TJA or a TJA-related operation, respectively. In Cox regressions, a large series of clinical and laboratory variables, which primarily reflected disease activity, predicted TJA. Smoking, either past or present, had a protective effect. Patients with highly abnormal values on the Health Assessment Questionnaire Disability Scale, global severity, and erythrocyte sedimentation rate had a 3-6 times increased risk of TJA.

CONCLUSION

TJA, a marker of joint failure and of RA outcome, is predicted by self-report assessments of severity and function, and by a series of laboratory, radiographic, and clinical variables. Prediction improves with the extent of observation, and 2-year observations approach full-study observations in their accuracy. Most TJAs survive for a long time in RA.

The knee joint in rheumatoid arthritis

The knee joint is commonly damaged in polyarticular rheumatoid arthritis. Surgical management depends on the preservation of the articular cartilage and degree of synovitis. Arthroscopic synovectomy is performed in intractable synovitis with cartilage sparing. Technique of total knee replacement is more complex because of bone and soft-tissue damage in rheumatoid arthritis, and complications are more common, particularly infection. Overall, long-term results with knee arthroplasty have been excellent in rheumatoid arthritis, with improved function and reduction in pain in the vast majority of patients.

The press-fit condylar modular total knee system. Four-to-six-year results with a posterior-cruciate-substituting design

One hundred and eighteen patients who had had 150 consecutive primary total knee replacements (sixteen bilateral procedures) between February 1988 and February 1990, with insertion of the press-fit condylar modular total knee system with cement, were enrolled in a prospective study. Ninety-six patients (125 knees) were followed for an adequate interval (mean, 4.8 years; range, 3.8 to 6.2 years). Thirteen patients (fifteen knees) died, and nine patients (ten knees) were lost to follow-up. The mean age of the patients at the time of the index arthroplasty was seventy years (range, twenty-nine to eighty-five years). The patients were evaluated clinically and radiographically, according to the scoring system of the Knee Society, and the results on a self-administered questionnaire were used to evaluate pain, function, satisfaction, and patellofemoral symptoms. A Kaplan-Meier survivorship analysis was performed with a revision operation as the end point. The mean functional and clinical scores, according to the system of the Knee Society, were 78 and 93 points, respectively, at the most recent follow-up examination. The result was excellent for 103 knees, good for thirteen, fair for three, and poor for six. Three revision operations were necessary: two because of infection and one because of instability. The over-all rate of patellofemoral symptoms was 8 per cent (ten knees). Three knees had tibiofemoral instability; subsequent modification of the design of the tibial cam decreased the prevalence of this problem. Non-progressive radiolucent lines were present at the cement-bone interface in 39 per cent (thirty-nine) of the ninety-nine knees that had complete radiographic follow-up. No prosthesis had loosened by the time of the most recent follow-up examination. The rate of survival of the implant was 97 per cent at six years, and the standard error of the mean was 1.6 per cent. In the present series, total knee arthroplasties with the press-fit condylar modular knee system resulted in excellent relief of pain, an excellent range of motion, and restoration of function. They were also associated with a low prevalence of patellofemoral problems.