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

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.

Evaluating Long Term Outcomes and Survivorship of Cruciate Retaining and Sacrificing Knee Replacements Done for Degenerative Arthritis in Patients Under 55 Years

BACKGROUND

Total Knee Arthroplasty (TKA) is the gold standard of treatment for end stage arthritis not responding to conservative treatment. With a recent increase in the younger population presenting with osteoarthritis (OA) we undertook this study to evaluate long-term outcomes and survivorship of TKA in this cohort.

MATERIALS AND METHODS

Our study cohort included 328 patients, < 55 years, with OA, who underwent TKA using Cruciate Retaining (CR), and Posterior Stabilized (PS) implants with a minimum follow up of 15 years. Revision surgery was the end point of our analysis and Kaplan-Meier evaluation of survivorship was measured. Knee Society Scores (KSS) and Range of Motion (ROM) were assessed to evaluate outcomes.

RESULTS

Survivorship of the CR and PS implants with revision as end point, for aseptic loosening was 97.3% and 96%, and revision for all causes was 89.7% and 86.1%, respectively, at 15 years. The outcomes of CR implants were better than the PS cohort in terms of function and survivorship.

CONCLUSION

Long term survivorship and outcome analysis of TKA in patients < 55 years showed good results with excellent survivorship, with both CR and PS implants. The CR cohort demonstrated better long-term survivorship, though the difference was not statistically significant. Deep infection and aseptic loosening were the commonest causes for failure.

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.].

Establishing Age-Specific Cost-Effective Annual Revision Rates for Unicompartmental Knee Arthroplasty: A Meta-Analysis

BACKGROUND

Improved survivorship has contributed to the increased use of unicompartmental knee arthroplasty (UKA) as an alternative to total knee arthroplasty (TKA) for unicompartmental knee osteoarthritis. However, heterogeneity among cost-effectiveness analysis studies comparing UKA to TKA has prevented the derivation of discrete implant survivorship targets. The aim of this meta-analysis was to determine the age-stratified annual revision rate (ARR) threshold for UKA to become consistently cost-effective for unicompartmental knee osteoarthritis.

METHODS

A systematic search was performed for cost-effectiveness analysis studies of UKA vs TKA. Selected publications were rated by evidence level and assessed for methodological quality. Target UKA survivorship values determined by sensitivity analysis were retrieved, converted to ARR, and combined by age category (<65, 65-74, and ≥75 years) to estimate age-specific cost-effectiveness thresholds.

RESULTS

Four studies met all inclusion criteria. All publications were evidence level I-B, with high methodological quality. Combined data indicated median threshold cost-effective ARR of 1.471% (interquartile range [IQR], 1.415-1.833; age <65), 1.135% (IQR, 1.011-1.260; age 65-74), and 1.760% (IQR, 1.660-2.880; age ≥75). Current revision rates are already below the cost-effective threshold for patients aged ≥75, but exceed recommended values in younger patients.

CONCLUSION

The findings indicate that implant survivorship is a limiting factor toward achieving cost-effective UKA in patients aged <65. Strategies to improve UKA survivorship, such as shifting procedures to high-volume centers, may render UKA cost-effective in younger patients. This presents an opportunity for resource reallocation within health systems to achieve cost-effective utilization of UKA across a broader population segment.

Total knee replacement in triple deformity with posterior subluxation of the knee joint

Dislocation or subluxation following total knee arthroplasty has been extensively reported, but vice versa that is total knee replacement for subluxed or dislocated knee has not been published. Triple deformity of knee that is flexion, external rotation, valgus at knee associated with posterior subluxation of tibia occurs in rheumatoid arthritis, advanced tubercular arthritis and neglected posttraumatic residual dislocated knee. A 50 year old female with seropositive rheumatoid arthritis had the above disabling deformity in left lower limb and varus with medial tibial thrust in the other. Bilateral total knee arthroplasty was planned. Conservative method of reduction of left knee posterior subluxation preoperatively by 90-90 skeletal traction failed; hence patient was subjected to a staged bilateral total knee replacement using an innovative technique. The most difficult and determining initial surgical step of knee replacement in such dislocated/subluxed knee is reduction of posterior subluxation and gaining flexion at knee, as only after gaining flexion and reducing dislocated tibia, will we be able to do knee arthroplasty in triple deformity of knee. These knees are grossly unstable as most of the capsule-ligamentous structures are attritioned/non-existent. So, a fine balance of bone cuts and soft-tissue release needs to be done in a sequential manner to fine tune valgus and posterior subluxation correction without jeoparadising neurovascular structures. After 3 years of knee arthroplasty the patient has painless, stable knee with good range of motion and is able to do all her activities, of living in a hilly terrain.

Total knee arthroplasty in patients with juvenile idiopathic arthritis

BACKGROUND

Total knee arthroplasty (TKA) for juvenile idiopathic arthritis is rare but is nonetheless indicated for many patients with this disease. Few reports exist on the results of TKA in patients with juvenile idiopathic arthritis.

QUESTIONS/PURPOSES

It was sought to determine (1) survivorship and (2) functional outcomes of TKAs in patients with juvenile idiopathic arthritis.

METHODS

Results were combined from patients treated by experienced surgeons at five hospitals between 1979 and 2011. Two hundred nineteen patients (349 TKAs) were identified and contacted to survey their outcomes at a minimum followup of 2 years (mean, 12 ± 8 years; range, 2-33 years). The average age at surgery was 28.9 ± 9.7 years (range, 11-58 years). Data on revision surgery and ability to perform daily activities were collected.

RESULTS

The 10-year survivorship was 95%, decreasing to 82% by 20 years. At latest followup, 31 of 349 TKAs (8.9%) had been revised for either polyethylene failure or loosening (18 TKAs), infection (four), stiffness (three), periprosthetic fractures (two), bilateral amputation for vascular reasons (two), patellar resurfacing (one), and instability (one). Walking tolerance was unlimited in 49%, five to 10 blocks in 23%, and less than five blocks in 28%. Eleven percent could not manage stairs, and another 59% depended on railings. A cane was used by 12% and crutches by 7%; 12% were wheelchair-dependent.

CONCLUSIONS

TKA survivorship in patients with juvenile idiopathic arthritis was inferior to that typically seen in younger patients with osteoarthritis or even rheumatoid arthritis confirming results of earlier studies with smaller patient numbers. This is especially disconcerting because younger patients require better durability of their TKAs.

Does cruciate-retaining total knee arthroplasty enhance knee flexion in Western and East Asian patient populations? A meta-analysis

INTRODUCTION

This study analyzed the published data to examine if CR TKAs can enhance the flexion and functional outcomes of the knee in the Western and East Asian populations using a meta-analysis approach.

MATERIALS AND METHODS

A systematic review of literature published through Medline and EMBASE was conducted. The inclusion criteria were: primary TKA, follow up duration greater than one year, a fixed bearing CR prosthesis, and data for maximum pre- and post-operative flexion along with standard deviations or errors. We estimated the weighted mean differences between pre- and post-operative flexion, extension and knee scores (KSS and HSS) via a random effect model.

RESULTS

Seventeen articles were selected and reviewed among 1229 studies that included 1090 knees of the Western and 516 knees of the East Asian. No significant difference was noted in maximal knee flexion pre- and post-operatively, when all the studies were pooled together (-0.17°, p=0.93, post-operative<pre-operative). The mean difference in flexion was -1.87° (p=0.2) and 2.03° (p=0.17), respectively in the both populations. However, the extension angle was significantly improved by -5.49° and -13.05° (p<0.05), respectively. KSS scores were significantly improved by 46.39 and 51.63, and HSS scores by 36.65 and 30.67 (p<0.05), respectively in the both populations.

CONCLUSION

The meta-analysis indicated that contemporary CR TKAs have not been shown to enhance post-operative flexion capability in the Western and East Asian. The extension angles of the knee and the knee scores were significantly improved in both populations.

Cruciate-retaining vs posterior-substituting inserts in total knee arthroplasty: functional outcome comparison

Despite clinical success, it is unclear which one, posterior-substituting (PS) or cruciate-retaining (CR) insert, has superior functional outcomes or longevity. We compared the collected results from 2 institutional review board-approved, multicenter, prospective observational studies following CR (412) and PS inserts (328). Participants were evaluated preoperatively, at 6 weeks, at 3 months, and at 1 and 2 years regarding pain, motion, function (Knee Society Score, Krackow Activity Score, Short Form-36), and procedure variables such as anesthesia and preoperative/perioperative/postoperative complications. Implant longevity was recorded at the 2-year follow-up. Improvement was observed within each group; however, there was no difference between groups in terms of pain, motion, or function at any end point. Two-year survival rate was higher than 95%. A higher incidence of wound hematoma was observed in the PS group. Both inserts can be used expecting satisfactory outcomes and high survival rates at 2 years.

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.

The role of the posterior cruciate ligament in total knee replacement

OBJECTIVES

The purpose of this study was to examine the effect of posterior cruciate ligament (PCL) retention, PCL recession, and PCL excision during cruciate-retaining total knee replacement.

METHODS

A total of 3018 anatomic graduated component total knee replacements were examined; 1846 of these retained the PCL, 455 PCLs were partially recessed, and in 717 the PCL was completely excised from the back of the tibia.

RESULTS

Clinical scores between PCL groups favored excision for flexion (p < 0.0001), and recession and retention for stairs (p < 0.0001). There was a mild difference in long-term all-cause aseptic survivorship between PCL-retained (96.4% at 15 years) combined with PCL-recessed groups (96.6% at 15 years) when compared with the PCL-excised group (95.0% at 15 years) (p = 0.0411, Wilcoxon; p = 0.0042, log-rank), as well as tibial or femoral loosening, which reported prosthesis survival of 97.8% at 15 years for PCL-retained knees, 98.2% for recessed knees, and 96.4% for excised knees (p = 0.0934, Wilcoxon; p = 0.0202, log-rank).

CONCLUSIONS

Despite some trade off in clinical performance, if the PCL is detached at the time of operation, conversion to a posterior-stabilised prosthesis may not be necessarily required as long as stability in the anteroposterior and coronal planes is achieved.

Previous fracture surgery is a major risk factor of infection after total knee arthroplasty

PURPOSE

Total knee arthroplasty (TKA) has been proven to be the most effective treatment for patients with severe joint disease. Although infection is not a frequent complication, it is certainly one of the most dreaded. The purpose of this study was to identify factors associated with infection after TKA.

METHODS

Between 1995 and 2006, 2,022 primary TKAs in 1,146 patients were evaluated. Flexible Nichidai Knee (FNK) was used as a prothesis in all subjects. Twenty-four patient-specific data items were collected via chart review for each patient. Revision arthroplasty procedures and infected knees were excluded. The medical records were reviewed to extract the following information: age, gender, body mass index (BMI), preoperative C-reactive protein (CRP), preoperative erythrocyte sedimentation rate (ESR), preoperative total protein (TP), duration of surgery, operative blood loss, total blood loss, duration of surgical drain, duration of antibiotic prophylaxis, primary diagnoses, smoking, diabetes mellitus, steroid or disease modifying anti-rheumatic drugs (DMARDs) therapy, previous operation around the knee joint, previous arthroscopic surgery, previous non-arthroscopic surgery, previous high tibial osteotomy (HTO) or open reduction internal fixation (ORIF), remnants of previous internal fixation material, bone graft, patella replacement, and bone cement.

RESULTS

The median age of the patients at the time of primary TKA was 72 (range, 26-91) years. The median follow-up period after primary TKA was 42 (range, 6-145) months. During the study period, 17 infected knee arthroplasties in 17 patients were identified. Previous history of ORIF, male gender, remnants of previous internal fixation material, and BMI showed significant correlation with postoperative infection.

CONCLUSION

This study identified previous history of fracture and remnants of internal fixation as major risk factors of infection after TKA. For clinical relevance, surgeons should be aware of potential infection when performing TKA in patients with these risk factors and patients should be informed of the potential risks.

Posterior cruciate ligament-retaining total knee arthroplasty in patients with rheumatoid arthritis: a concise follow-up of a previous report

7We previously reported the minimum eight-year follow-up results of cruciate-retaining total knee arthroplasty in a consecutive series of seventy-two knees in patients with rheumatoid arthritis. In the present study, we evaluated the longer-term outcomes after twenty to twenty-five years of follow-up. Since the publication of our original study, ten knees have been revised: three because of periprosthetic fracture, three because of infection, two because of patellofemoral failure, and two because of posterior instability. The rate of implant survival at twenty years after surgery was 69% (95% confidence interval [CI], 56% to 79%) with revision for any reason as the end point, 81% (95% CI, 69% to 89%) with femoral or tibial component revision for any reason as the end point, and 93% (95% CI, 83% to 97%) with posterior instability as the end point. These long-term results demonstrate that posterior cruciate ligament insufficiency with instability was rarely the cause of failure following cruciate-retaining total knee arthroplasty in patients with rheumatoid arthritis.

Antibiotic bone cement and the incidence of deep infection after total knee arthroplasty

We asked if the use of antibiotic-laden bone cement (ALBC) decreased the deep infection rate after primary total knee arthroplasty as compared to plain bone cement. We surveyed 1625 consecutive patients for relevant covariates. Joint pain and function were assessed at baseline and at 1 year of follow-up with the Western Ontario McMaster University Osteoarthritis Index scores. The incidence of deep infection at 1-year follow-up was recorded. There were no differences in baseline covariates between groups (P > .05). We found a deep infection rate of 2.2% in the ALBC group and 3.1% in the plain bone cement group (P = .27). Adjusted analysis showed that ALBC was not predictive of a lower infection rate at 1 year (P = .84). Antibiotic-laden bone cement did not reduce the incidence of deep infection following primary total knee arthroplasty at 1-year follow-up.

Total knee replacement in the fixed valgus deformity using a lateral approach: role of the automatic iliotibial band release for a successful balancing

The purpose of this work was to document eleven years of experience in knee replacement for fixed knee valgus through a lateral approach with special emphasis on the balancing procedures. At a mean follow-up of seven years, only one revision for sepsis was required in this series of 63 knee replacements. The mean knee score improved from 37 (range 20-45) to 91 (range 65-100) at the last review (p < 0.01) while the function score increased from 29.5 (range 0-50) to 78.7 (range 10-100) (p = 0.01). The mean mechanical axis (HKA) was 14.7 degrees of valgus preoperatively and 1 degrees of valgus postoperatively. After the iliotibial band was automatically released in the approach, only four of 63 knees required additional release for tightness in extension. These results underline the appeal of the lateral approach with the automatic release of the iliotibial band. If required, additional ligament release is recommended step-by-step after bone section to avoid postoperative instability.

Navigation did not improve the precision of minimally invasive knee arthroplasty

Potential advantages of minimally invasive total knee arthroplasty (TKA) include decreased pain, faster recovery, and increased quadriceps muscle strength. Computer-assisted navigation has been associated with more accurate component alignment. We evaluated two groups of 50 patients who had minimally invasive TKAs performed with and without navigation by two surgeons. A comparison of 50 previous TKAs by each of the two surgeons showed similar results. The mean operative times for the navigation and nonnavigation groups were 112 minutes (range, 63-297 minutes) and 54 minutes (range, 35-86 minutes), respectively. The mean estimated blood losses, mean Knee Society pain as well as functional scores and mean component alignments were similar. The number of knees that deviated by more than 3 degrees from the normal anatomic axis was three and one in the navigated and nonnavigated groups, respectively. Complication rates were 6% and 4% in the navigated and nonnavigated groups, respectively. Our data demonstrate no distinct advantage of navigation when combined with a minimally invasive approach.

LEVEL OF EVIDENCE

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

Cruciate ligaments in arthritic knees: a histologic study with radiologic correlation

Anterior cruciate ligaments (ACLs) and posterior cruciate ligaments (PCLs) from 45 osteoarthritic knees were histologically examined to evaluate the frequency and grade the severity of degenerative changes, which were correlated with radiologic grade of arthritis and severity of deformity at the knee. Immunohistochemical staining was used to identify neurofilaments in 10 knees. A histologic score was generated for both cruciates based on changes found on light microscopy. The ACL was severely degenerated, absent, or disrupted in knees with radiologic arthritis higher than grade 3 and varus deformity exceeding 15 degrees . The PCL was moderately degenerated in most knees irrespective of the grade of arthritis and severity of deformity. Neurofilaments were present in all 10 PCLs and absent in 4 ACLs.

Infection after knee arthroplasty a prospective study of 1509 cases

We report a prospective study of 1509 consecutive total knee arthroplasties looking at risk factors for infection in modern surgical practice. The overall deep infection rate was 1%. A further 51 patients had a superficial infection (3.3%). Statistical analysis revealed no correlation between risk of infection and age and sex. Those who had poor health as assessed by the American Society of Anesthesiologists score had no increased risk of infection. Neither did patients undergoing arthroplasty for rheumatoid arthritis. Diabetic patients and those with morbid obesity (body mass index, >40 kg/m(2)) had an increased odds ratio for deep and superficial infection, but these results did not reach statistical significance.

Factors affecting anteroposterior instability following cruciate-retaining total knee arthroplasty in patients with rheumatoid arthritis

Controversy persists concerning around posterior cruciate ligament (PCL) retention in total knee arthroplasty (TKA) for patients with rheumatoid arthritis (RA). This study investigated factors affecting anteroposterior (AP) instability following cruciate-retaining (CR)-TKA. In a consecutive series of 70 knees from 52 RA patients, total displacement (TD) was measured using a KT-2000 arthrometer before and after CR-TKA under anesthesia, and changes in TD were defined as DeltaTD. TD was also measured under anesthesia in 65 knees from 48 RA patients at a mean of 7.5 years after CR-TKA. Mean postoperative TD was 9.4+/-0.95 mm, representing an increase of about 1.5-1.8 mm compared to preoperative TD, and possibly reflecting resection of the anterior cruciate ligament. Correlation analysis revealed significant negative correlations between DeltaTD and both preoperative flexion angle (r=-0.67, p<0.001) and preoperative extension angle (r=-0.63, p<0.001), suggesting that TD in knees with flexion contracture increased postoperatively. At medium-term follow-up, no patients displayed AP instability, and mean TD was 8.3+/-0.48 mm. A significant correlation was found between TD and permissible flexion angle (r=0.61, p<0.001). These results indicate that TD is basically maintained during the course of CR-TKA in RA, but may be slightly affected by factors other than the PCL itself.

Navigated shorter incision or smaller implant in knee arthritis?

Minimally invasive approaches for unicompartmental knee arthroplasty are well-accepted for treating knee arthritis because of the smaller implant size, shorter operative time, and tissue-sparing nature of the procedure. With the introduction of computer alignment systems, a well-aligned and balanced total knee arthroplasty (TKA) can be achieved even with smaller surgical exposures. We hypothesized a unicompartmental knee arthroplasty would provide better midterm outcomes than a computer-assisted minimally invasive TKA in patients with isolated medial compartment knee arthritis. We matched (preoperative arthritis severity, age, gender, and preoperative range of motion) 64 knees that had a medial unicompartmental knee arthroplasty or a mini-incision computer-assisted TKA. All patients had a varus deformity no greater than 8 degrees and a body mass index lower than 30 kg/m. Patients were followed a minimum of 48 months. In the mini-incision computer-assisted TKA group, all the implants were positioned within 4 degrees of ideal alignment. The surgical time and hospital stay were longer in the computer-assisted TKA group. A unicompartmental knee arthroplasty was estimated to cost at least 3100 euros (approximately US $4100) less. The clinical assessment showed higher functional and Italian Orthopaedic UKA Users Group scores for the unicompartmental knee arthroplasty group.

Cemented total knee arthroplasty using a modern prosthesis in young patients with osteoarthritis

Fifty-two consecutive cemented total knee arthroplasties were performed using the Press-Fit Condylar (DePuy, Warsaw, Ind) knee system on patients aged 55 years or younger at Mayo Clinic Rochester from 1988 to 1994. Patients were followed for a minimum of 10 years, with an average follow-up of 12 years (range, 10-15 years). There were 8 total revisions (15%), including 2 revisions before 10 years, one for sepsis at 1 year, and one for instability at 8 years. Six revisions occurred between 10 and 15 years, all associated with polyethylene wear and osteolysis. Implant survival rate was estimated to be 96% at 10 years and 85% at 15 years of follow-up.

Antibiotic-loaded bone cement for infection prophylaxis in total joint replacement

Use of antibiotic-loaded bone cement for prophylaxis against infection is not indicated for patients not at high risk for infection who are undergoing routine primary or revision joint replacement with cement. The mechanical and elution properties of commercially available premixed antibiotic-loaded bone-cement products are superior to those of hand-mixed preparations. Use of commercially available antibiotic-loaded bone-cement products has been cleared by the United States Food and Drug Administration only for use in the second stage of a two-stage total joint revision following removal of the original prosthesis and elimination of active periprosthetic infection. Use of antibiotic-loaded bone cement for prophylaxis against infection in the second stage of a two-stage total joint revision involves low doses of antibiotics. Active infection cannot be treated with commercially available antibiotic-loaded bone cement as such treatment requires higher doses of antibiotics.

Long-term results of total knee arthroplasty in young patients with rheumatoid arthritis

Forty-seven cemented total knee arthroplasties in 32 patients with rheumatoid arthritis who were 55 years or younger (average, 43) were followed until death or a minimum of 15 years. The average follow-up was 18 years. There were 6 revisions; 5 of 6 revisions had severe polyethylene wear and osteolysis. All revisions occurred after 17 years (range, 17-23). Three of these had fracture of the tibial component associated with polyethylene wear through; the remaining 2 had loose tibial and femoral components. One patient sustained a distal femoral periprosthetic fracture requiring revision of the total knee. Cemented total knee arthroplasty in the young patient with rheumatoid arthritis is reliable and durable at an average 18 years of follow-up with an estimated survivorship of 100% at 15 years and 93.7% at 20 years.