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

Outcome measures analysis following total knee arthroplasty in patients with severe haemophilic arthropathy of the knee

Total knee arthroplasty (TKA) has been the gold standard for treating severe haemophilic arthropathy of the knee when all conservative measures fail. However, performing a TKA in patients with haemophilic arthropathy is difficult due to severe joint deformity and destruction, and poor bone quality. The aim of the present study was to evaluate the short-term results of TKA in the treatment of knee haemophilic arthropathy in a tertiary referral centre, with an emphasis on health-related quality of life and knee function. A prospective study was conducted that included 19 male patients with end-stage haemophilic knee arthropathy who underwent TKA in a tertiary referral centre. Clinical outcome and health-related quality of life were assessed by the Western Ontario and McMaster Universities Arthritis (WOMAC) index and the Short Form-36 (SF-36) both pre-operatively and at 1-year post-operatively. The mean age of the patients was 50.37±7.63 years (range, 40-65 years). Pre-operative health-related quality of life was impaired in all patients in all SF-36 domains but was markedly improved after TKA. Knee function in all dimensions (pain, stiffness and physical function), as measured by the WOMAC questionnaire, significantly improved after TKA. Pre-operative pain, stiffness and function, along with total WOMAC score, were strongly and negatively correlated with pre-operative SF-36. Overall, the present study indicated a significant improvement in quality of life and clinical outcome after TKA in patients with advanced haemophilic arthropathy. More studies with longer follow-up periods in a larger population are needed to fully elucidate the mid- and long-term values of TKA in haemophilic patients.

Impacts of Knee Arthroplasty on Activity Level and Knee Function in Young Patients: A Systematic Review

The annual demand for knee arthroplasty has been steadily rising, particularly in younger patients. The primary objective of this systematic review was to determine the impact of knee arthroplasties on knee function and activity levels in young (≤55 years) patients. A PubMed search from inception (1977) to March 2022 to identify eligible studies produced 640 peer-reviewed studies for consideration. A total of 18 studies including 4,186 knee arthroplasties in 3,200 patients (mean patient age at the time of surgery: 47.4 years, range: 18-55 years) were ultimately included for analysis. Mean final follow-up (FFU) duration was 5.8 years (range: 2-25.1 years). Mean FFU improvement in Knee Society Clinical Score was 48.0 (1,625 knees, range: 20.9-69.0), Knee Society Function Score was 37.4 (1,284 knees, range: 20-65). Mean FFU for the Tegner and Lysholm activity scale was 2.8 (4 studies, 548 knees, range: 0.7-4.2); University of California Los Angeles Physical Activity Questionnaire score was 2.8 (3 studies, 387 knees, range: 1.2-5); lower extremity activity scale was 1.84 (529 knees). The available evidence suggest that young patients typically realize sustained improvements in knee function compared to preoperative levels; however, these improvements do not typically translate into a return to desired activity levels or quality of life, and this patient population should expect a higher and earlier risk for revision than their older counterparts. Further research, including robust registry data, is needed to establish evidence-based indications, expectations, and prognoses for outcomes after knee arthroplasty in young and active patients.

Total knee arthroplasty survivorship and outcomes in young patients: a review of the literature and 40-year update to a longitudinal study

INTRODUCTION

Growing numbers of younger patients are electing to undergo total knee arthroplasty (TKA) for end-stage osteoarthritis. The purpose of this study was to compare established literature regarding TKA outcomes in patients under age 55, to data from an ongoing longitudinal young patient cohort curated by our study group. Further, we aimed to provide a novel update on survivorship at 40 years post-TKA from our longitudinal cohort.

METHODS

A literature search was conducted using the electronic databases PubMed, Embase, and Cochrane Library, using terms related to TKA, patients under age 55, and osteoarthritis. Demographic and outcome data were extracted from all studies that met the inclusion criteria. Data were divided into the "longitudinal study (LS) group," and the "literature review (LR) group" based on the patient population of the study from which it came.

RESULTS

After screening, 10 studies met the inclusion criteria; 6 studies comprised the LR group, and 4 studies comprised the LS group. 2613 TKAs were performed among the LR group, and 114 TKAs were longitudinally followed in the LS group. The mean patient ages of the LR and LS groups were 46.1 and 51, respectively. Mean follow-up was 10.1 years for the LR group. Mean postoperative range of motion was 113.6° and 114.5° for the LR and LS groups, respectively. All-cause survivorship reported at 10 years or less ranged from 90.6% to 99.0%. The LS cohort studies reported survivorship ranges of 70.1-70.6% and 52.1-65.3% at 30 and 40 years, respectively.

CONCLUSIONS

Young TKA patients demonstrated improved functionality at each follow-up time point assessed. Survivorship decreased with increasing lengths of follow-up, ultimately ranging from 52.1-65.3% at 40 years post-TKA. The paucity of literature on long-term TKA outcomes in this patient population reinforces the necessity of further research on this topic.

What Are the All-Cause Survivorship Rates and Functional Outcomes in Patients Younger Than 55 Years Undergoing Primary Knee Arthroplasty? A Systematic Review

BACKGROUND

Approximately one-fourth of TKAs will be performed in patients 55 years or younger within the next decade. Postoperative outcomes for younger patients who had a knee arthroplasty were systematically reviewed in 2011; however, numerous studies evaluating young patients who had both a TKA and unicompartmental knee arthroplasty (UKA) have been reported in the past decade. Therefore, to better counsel this growing population of young patients undergoing knee arthroplasty, an updated understanding of their expected postoperative outcomes is warranted.

QUESTIONS/PURPOSES

In this systematic review, we evaluated (1) all-cause survivorship, (2) reasons for revision, (3) patient-reported outcomes, and (4) return to physical activity and sport in patients 55 years or younger undergoing primary TKA or UKA.

METHODS

A comprehensive search of PubMed, Medline, SportDiscus, and CINAHL was performed to identify all original studies evaluating outcomes after primary knee arthroplasty for young patients (55 years of age or younger) from inception until March 2021. The following keywords were used: knee, arthroplasty, replacement, pain, function, revision, survivorship, sport, physical activity, and return to play. Only original research studies that were related to knee arthroplasty and reported postoperative outcomes with a minimum 1-year follow-up for patients 55 years or younger were included. Unpublished materials, publications not available in English, and studies with a primary diagnosis of rheumatoid arthritis were excluded. The Methodological Index for Non-Randomized Studies (MINORS) score was used to evaluate the study quality of case series and comparative studies, while the Cochrane Risk of Bias tool and the Jadad scale were used for randomized studies. The primary outcomes of interest for this study were all-cause survivorship rate, reasons for all-cause revision, Knee Society and Knee Society Function scores (minimum clinically important difference [MCID] 7.2 and 9.7, respectively), WOMAC scores (MCID 10), Tegner scores (no reported MCID for knee arthroplasty), and return to physical activity or sport. Knee Society and Knee Society Function scores range from 0 to 100, with scores from 85 to 100 considered excellent and below 60 representing poor outcomes. All-cause survivorship rate and reasons for revision were both reported in 17 total studies. Knee Society scores were presented in 19 and Knee Society Function scores were reported in 18 included studies. WOMAC scores and Tegner scores were each found in four included studies, and return to physical activity and return to sport analyses were performed in seven studies. Overall, 21 TKA studies and five UKA studies were included in this analysis, featuring 3095 TKA knees and 482 UKA knees.

RESULTS

Kaplan-Meier estimates of all-cause survivorship ranged from 90% to 98% at 5 to 10 years of follow-up after TKA and from 84% to 99% (95% CI 93% to 98%) at 10 years to 20 years post-TKA. All-cause UKA survivorship was 90% at 10 years and 75% at 19 years in the largest Kaplan-Meier estimate of survivorship for patients younger than 55 who underwent UKA. Common reasons for revision in TKA patients were polyethylene wear/loosening, aseptic tibial loosening, and infection, and in UKA patients the common reasons for revision were knee pain, aseptic loosening, progression of knee osteoarthritis, and polyethylene wear/loosening. Knee Society scores ranged from 85 to 98 for 5-year to 10-year follow-up and ranged from 86 to 97 at 10-year to 20-year follow-up in TKA patients. Knee Society Function scores ranged from 70 to 95 for 5-year to 10-year follow-up and ranged from 79 to 86 at 10-year to 20-year follow-up. Return to physical activity and sport was reported variably; however, most patients younger than 55 have improved physical activity levels after knee arthroplasty relative to preoperative levels.

CONCLUSION

Although all-cause survivorship rates were frequently above 90% and patient-reported outcome scores were generally in the good to excellent range, several studies reported long-term survivorship rates from 70% to 85% and fair patient-reported outcome scores, which must be factored into any preoperative counseling with patients. We could not control for surgeon volume in this report, and prior research suggests that increasing volume is associated with less frequent complications; in addition, the studies we included were variably affected by selection bias, transfer bias, and assessment bias, which makes it likely that the findings of our review represent best-case estimates. To limit the frequency of revision in patients younger than 55 years undergoing TKA, clinicians should be cautious of polyethylene wear/loosening, aseptic tibial loosening, and infection, while knee pain and progression of knee osteoarthritis are also common reasons for revision in patients younger than 55 undergoing UKA. Further research should isolate younger knee arthroplasty patients and evaluate postoperative activity levels while accounting for preoperative physical activity and sport participation.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

3D-printed porous tantalum: recent application in various drug delivery systems to repair hard tissue defects

INTRODUCTION

The treatment of hard tissue defects, especially those of bone and cartilage, induced by infections or tumors remains challenging. Traditional methods, including debridement with systematic chemotherapy, have shortcomings owing to their inability to eliminate infections and high systematic toxicity.

AREA COVERED

This review comprehensively summarizes and discusses the current applications of 3D-printed porous tantalum (3D-P-p-Ta), a novel drug delivery strategy, in drug delivery systems to repair hard tissue defects, as well as the limitations of existing data and potential future research directions.

EXPERT OPINION

Drug delivery systems have advanced medical treatments, with the advantages of high local drug concentration, long drug-release period, and minimal systematic toxicity. Due to its excellent biocompatibility, ideal mechanical property, and anti-corrosion ability, porous tantalum is one of the most preferable loading scaffolds. 3D printing allows for freedom of design and facilitates the production of regular porous implants with high repeatability. There are several reports on the application of 3D-P-p-Ta in drug delivery systems for the management of infection- or tumor-associated bone defects, yet, to the best of our knowledge, no reviews have summarized the current research progress.

Can Octogenarians Undergoing Total Knee Arthroplasty Experience Similar Functional Outcomes, Quality of Life, and Satisfaction Rates as Their Younger Counterparts? A Propensity Score Matched Analysis of 1188 Patients

BACKGROUND

Current literature lacks consensus regarding the impact of advanced age on the clinical outcomes of total knee arthroplasty (TKA). Moreover, there is paucity of literature on the subjective benefit reported by elderly patients. We compared the functional outcomes, quality of life, and satisfaction rates between octogenarians and age-appropriate controls undergoing primary TKA with a minimum follow-up of 2 years.

METHODS

Prospectively collected registry data of 594 patients aged ≥80 years (n = 594) and a propensity score matched cohort of 594 patients aged 65-74 years who underwent primary TKA at a single institution were reviewed. The range of motion, clinical outcome scores, and satisfaction rates were assessed at 6 months and 2 years. Revision rates were also recorded.

RESULTS

Octogenarians had a significantly lower Knee Society Function Score, Oxford Knee Score, and SF-36 Physical Component Summary at 6 months and 2 years (P < .05 for each). Furthermore, a lower proportion of octogenarians achieved the minimal clinically important difference for each score (P < .05 for each). Although the rates were similar at 6 months (P = .853), octogenarians were less satisfied at 2 years compared to age-appropriate controls (89.3% vs 93.3%, P = .042), and there was a trend toward poorer expectation fulfillment (88.4% vs 92.1%, P = .062).

CONCLUSION

Octogenarians undergoing TKA had a relatively lower rate of satisfaction and clinically meaningful improvement compared to younger controls. Nevertheless, elderly patients still experienced a successful outcome after surgery. The clinical trajectory outlined may help clinicians provide valuable prognostic information to elderly patients and guide preoperative counseling.

Long-term results of total knee arthroplasty in hemophilic arthropathy

PURPOSE

Knee arthropathy is a frequent complication affecting hemophilic patients, which can cause severe pain and disability. When conservative measures fail, total knee arthroplasty (TKA) may be performed.

METHODS

Eighteen TKA were performed in 15 patients with hemophilia during a 24-year period in a Hemophilia Comprehensive Care Center. All patients were evaluated by a multidisciplinary team constituted by a hematologist, an orthopedic surgeon, and a physical medicine and rehabilitation physician. Mean follow-up was 11.3 years.

RESULTS

Ten-year survival rate with prosthesis removal as end point was 94.3%. At last, follow-up visual analog pain scale score was 3.2 points, knee osteoarthritis outcome scale was 86.7 points, and mean range of motion was 88°. Only two patients required perioperative transfusion. Complication rate was 27.8% and included two infections, two prosthesis stiffness, and one case of recurrent hemarthrosis.

CONCLUSION

After appropriate medical optimization and with prompt rehabilitation, TKA can be performed in hemophilic patients with good clinical results and survivor rates comparable to nonhemophilic patients.

Does Robotic-assisted TKA Result in Better Outcome Scores or Long-Term Survivorship Than Conventional TKA? A Randomized, Controlled Trial

BACKGROUND

Robotic-assisted TKA was introduced to enhance the precision of bone preparation and component alignment with the goal of improving the clinical results and survivorship of TKA. Although numerous reports suggest that bone preparation and knee component alignment may be improved using robotic assistance, no long-term randomized trials of robotic-assisted TKA have shown whether this results in improved clinical function or survivorship of the TKA.

QUESTIONS/PURPOSES

In this randomized trial, we compared robotic-assisted TKA to manual-alignment techniques at long-term follow-up in terms of (1) functional results based on Knee Society, WOMAC, and UCLA Activity scores; (2) numerous radiographic parameters, including component and limb alignment; (3) Kaplan-Meier survivorship; and (4) complications specific to robotic-assistance, including pin-tract infection, peroneal nerve palsy, pin-site fracture, or patellar complications.

METHODS

This study was a registered prospective, randomized, controlled trial. From January 2002 to February 2008, one surgeon performed 975 robotic-assisted TKAs in 850 patients and 990 conventional TKAs in 849 patients. Among these patients 1406 patients were eligible for participation in this study based on prespecified inclusion criteria. Of those, 100% (1406) patients agreed to participate and were randomized, with 700 patients (750 knees) receiving robotic-assisted TKA and 706 patients (766 knees) receiving conventional TKA. Of those, 96% (674 patients) in the robotic-assisted TKA group and 95% (674 patients) in the conventional TKA group were available for follow-up at a mean of 13 (± 5) years. In both groups, no patient older than 65 years was randomized because we anticipated long-term follow-up. We evaluated 674 patients (724 knees) in each group for clinical and radiographic outcomes, and we examined Kaplan-Meier survivorship for the endpoint of aseptic loosening or revision. Clinical evaluation was performed using the original Knee Society knee score, the WOMAC score, and the UCLA activity score preoperatively and at latest follow-up visit. We also assessed loosening (defined as change in the position of the components) using plain radiographs, osteolysis using CT scans at the latest follow-up visit, and component, and limb alignment on mechanical axis radiographs. To minimize the chance of type-2 error and increase the power of our study, we assumed the difference in the Knee Society score to be 25 points to match the MCID of the Knee Society score with a SD of 5; to be able to detect a difference of this size, we calculated that a total of 628 patients would be needed in each group in order to achieve 80% power at the α = 0.05 level.

RESULTS

Clinical parameters at the latest follow-up including the Knee Society knee scores (93 ± 5 points in the robotic-assisted TKA group versus 92 ± 6 points in the conventional TKA group [95% confidence interval 90 to 98]; p = 0.321) and Knee Society knee function scores (83 ± 7 points in the robotic-assisted TKA group versus 85 ± 6 points in the conventional TKA group [95% CI 75 to 88]; p = 0.992), WOMAC scores (18 ± 14 points in the robotic-assisted TKA group versus 19 ± 15 points in the conventional TKA group [95% CI 16 to 22]; p = 0.981), range of knee motion (125 ± 6° in the robotic-assisted TKA group versus 128 ± 7° in the conventional TKA group [95% CI 121 to 135]; p = 0.321), and UCLA patient activity scores (7 points versus 7 points in each group [95% CI 5 to 10]; p = 1.000) were not different between the two groups at a mean of 13 years' follow-up. Radiographic parameters such as the femorotibial angle (mean 2° ± 2° valgus in the robotic-assisted TKA group versus 3° ± 3° valgus in the conventional TKA group [95% CI 1 to 5]; p = 0.897), femoral component position (coronal plane: mean 98° in the robotic-assisted TKA group versus 97° in the conventional TKA group [95% CI 96 to 99]; p = 0.953; sagittal plane: mean 3° in the robotic-assisted TKA group versus 2° in the conventional TKA group [95% CI 1 to 4]; p = 0.612) and tibial component position (coronal plane: mean 90° in the robotic-assisted TKA group versus 89° in the conventional TKA group [95% CI 87 to 92]; p = 0.721; sagittal plane: 87° in the robotic-assisted TKA group versus 86° in the conventional TKA group [95% CI 84 to 89]; p = 0.792), joint line (16 mm in the robotic-assisted TKA group versus 16 mm in the conventional TKA group [95% CI 14 to 18]; p = 0.512), and posterior femoral condylar offset (24 mm in the robotic-assisted TKA group versus 24 mm in the conventional TKA group [95% CI 21 to 27 ]; p = 0.817) also were not different between the two groups (p > 0.05). The aseptic loosening rate was 2% in each group, and this was not different between the two groups. With the endpoint of revision or aseptic loosening of the components, Kaplan-Meier survivorship of the TKA components was 98% in both groups (95% CI 94 to 100) at 15 years (p = 0.972). There were no between-group differences in terms of the frequency with which complications occurred. In all, 0.6% of knees (four) in each group had a superficial infection, and they were treated with intravenous antibiotics for 2 weeks [corrected]. No deep infection occurred in these knees. In the conventional TKA group, 0.6% of knees (four) had motion limitation (< 60°) [corrected].

CONCLUSIONS

At a minimum follow-up of 10 years, we found no differences between robotic-assisted TKA and conventional TKA in terms of functional outcome scores, aseptic loosening, overall survivorship, and complications. Considering the additional time and expense associated with robotic-assisted TKA, we cannot recommend its widespread use.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Cementless versus cemented total knee arthroplasty in young patients: a meta-analysis of randomized controlled trials

Purpose

Optimal type of prosthesis in total knee arthroplasty (TKA) remains controversial for young patients. The objective of this meta-analysis is to compare cementless and cemented fixation in TKA.

Methods

In this meta-analysis, we conducted electronic searches of PubMed, Embase, Cochrane Library, and Web of Science in December 2018. We collected randomized controlled trials (RCTs) comparing cementless and cemented TKA in young patients. The outcome measurements consisted of functional outcomes, Knee Society Score, range of motion, radiological outcomes, pain score, and complications. Stata 12.0 software was used for our meta-analysis. Quality assessment for RCTs was conducted according to the Cochrane Handbook for systematic review of interventions.

Results

Four RCTs met our inclusion criteria with 255 patients in cemented groups and 229 patients in cementless groups. The present meta-analysis indicated that there was a significant difference between the groups in terms of radiological outcomes and pain score. No significant difference was found regarding KSS, range of motion, or complications.

Conclusion

Cementless TKA was associated with superior outcomes in terms of radiological outcomes and pain score compared with cemented fixation. We found no significant difference regarding the functional outcome or aseptic loosening between groups. High-quality RCTs were still required for further investigation.

Outcome of knee arthroplasty in patients aged 65 years or less: a prospective study of 232 patients with 2-year follow-up

BACKGROUND AND AIMS

Previous studies have reported lower implant survival rates, residual pain, and higher patient dissatisfaction rates following knee arthroplasty in younger knee arthroplasty patients. We aimed to assess the real-world effectiveness of knee arthroplasty in a prospective non-selected cohort of patients aged 65 years or less with 2-year follow-up.

MATERIAL AND METHODS

In total, 250 patients (272 knees) aged 65 years or less were enrolled into this prospective cohort study. Patient-reported outcome measures were used to assess the outcome.

RESULTS

The mean Oxford Knee Score and all Knee Injury and Osteoarthritis Outcome Score subscales increased significantly (p < 0.001) from preoperative situation to the 2-year follow-up. Significant increase (p < 0.001) in physical activity was detected in High-Activity Arthroplasty Score and RAND-36 Physical Component Score (PCS). Pain was also significantly (p < 0.001) relieved during the follow-up. Total disappearance of pain was rare at 2 years. Patients with milder (Kellgren-Lawrence grade 2) osteoarthritis were less satisfied and reported poorer patient-reported outcome measure than those with advanced osteoarthritis (Kellgren-Lawrence grade 3-4). There was no difference in the outcome (any patient-reported outcome measure) between patients who underwent total knee arthroplasty and those who received unicondylar knee arthroplasty.

CONCLUSION

We found that measured with a wide set of patient-reported outcome measures, both total knee arthroplasty and unicondylar knee arthroplasty resulted in significant pain relief, as well as improvement in physical performance and quality of life in patients aged 65 years or less. Real-world effectiveness of these procedures seems to be excellent. 15% of patients still had residual symptoms and were dissatisfied with the outcome at 2 years after the operation.

Preoperative tibial mechanical axis orientation and articular surface design influence on the coronal joint line orientation relative to the ground during gait after total knee arthroplasties

PURPOSE

Neutral lower limb alignment does not necessarily produce a horizontal joint line after total knee arthroplasty (TKA). The orientation of the pre- and postoperative tibial mechanical axes (TMAs-G), tibial component, and joint line relative to the ground were evaluated.

METHODS

The study group included 46 knees, 23 posterior-stabilized (PS) and 23 bicruciate-stabilized (BCS) TKAs. Using whole-leg standing radiographs, the static orientation of the pre- and postoperative TMAs-G and the tibial component as well as the postoperative alignment were measured. Applying image-matching techniques, the dynamic coronal orientation of the tibial component and joint line over the stance phase of gait were analysed. The correlation between static and dynamic orientation of the tibial component and differences in the joint line between the PS and BCS TKAs were evaluated.

RESULTS

In standing, the postoperative TMA-G (0.8° ± 2.8°) and tibial component (1.5° ± 2.4°) were laterally tilted with a strong correlation. The preoperative lateral tilt of the TMA-G (7.9° ± 5.1°) was a significant predictor of the postoperative TMA-G. The lateral tilt of the tibial component increased to 5.1° ± 2.4° on dynamic analysis, and was moderately correlated to static orientation. The dynamic orientation of the joint line was smaller for the BCS (1.8° ± 2.4°) compared to the PS (5.5° ± 2.7°) TKA.

CONCLUSION

Even with a mechanically well-aligned TKA, a lateral tilt of the tibial component was identified due to the lateral tilt of the postoperative TMA-G and the stance phase of gait. The BCS can better accommodate the residual lateral tilt of the joint line due to the 3° medial inclination of the joint surfaces of the implant. This study increases the awareness of surgeons regarding the possibility of the coronal joint line orientation to influence preoperative TMA-G and be accommodated by articular surface design, even in mechanically aligned TKA.

LEVEL OF EVIDENCE

IV.

The projected burden of complex surgical site infections following hip and knee arthroplasties in adults in the United States, 2020 through 2030

BACKGROUND

As the US population ages, the number of hip and knee arthroplasties is expected to increase. Because surgical site infections (SSIs) following these procedures contribute substantial morbidity, mortality, and costs, we projected SSIs expected to occur from 2020 through 2030.

METHODS

We used a stochastic Poisson process to project the number of primary and revision arthroplasties and SSIs. Primary arthroplasty rates were calculated using annual estimates of hip and knee arthroplasty stratified by age and gender from the 2012-2014 Nationwide Inpatient Sample and standardized by census population data. Revision rates, dependent on time from primary procedure, were obtained from published literature and were uniformly applied for all ages and genders. Stratified complex SSI rates for arthroplasties were obtained from 2012-2015 National Healthcare Safety Network data. To evaluate the possible impact of prevention measures, we recalculated the projections with an SSI rate reduced by 30%, the national target established by the US Department of Health and Human Services (HHS).

RESULTS

Without a reduction in SSI rates, we projected an increase in complex SSIs following hip and knee arthroplasty of 14% between 2020 and 2030. We projected a total burden of 77,653 SSIs; however, meeting the 30% rate reduction could prevent 23,297 of these SSIs.

CONCLUSIONS

Given current SSI rates, we project that complex SSI burden for primary and revision arthroplasty may increase due to an aging population. Reducing the SSI rate to the national HHS target could prevent 23,000 SSIs and reduce subsequent morbidity, mortality, and Medicare costs.

Comparison of High-Flexion Fixed-Bearing and High-Flexion Mobile-Bearing Total Knee Arthroplasties-A Prospective Randomized Study

BACKGROUND

There is none, to our knowledge, about comparison of high-flexion fixed-bearing and high-flexion mobile-bearing total knee arthroplasties (TKAs) in the same patients. The purpose of this study was to determine whether clinical results; radiographic and computed tomographic scan results; and the survival rate of a high-flexion mobile-bearing TKA is better than that of a high-flexion fixed-bearing TKA.

METHODS

The present study consisted of 92 patients (184 knees) who underwent same-day bilateral TKA. Of those, 17 were men and 75 were women. The mean age at the time of index arthroplasty was 61.5 ± 8.3 years (range 52-65 years). The mean body mass index was 26.2 ± 3.3 kg/m² (range 23-34 kg/m²). The mean follow-up was 11.2 years (range 10-12 years).

RESULTS

The Knee Society knee scores (93 vs 92 points; P = .531) and function scores (80 vs 80 points; P = 1.000), WOMAC scores (14 vs 15 points; P = .972), and UCLA activity scores (6 vs 6 points; P = 1.000) were not different between the 2 groups at 12 years follow-up. There were no differences in any radiographic and CT scan parameters between the 2 groups. Kaplan-Meier survivorship of the TKA component was 98% (95% confidence interval, 93-100) in the high-flexion fixed-bearing TKA group and 99% (95% confidence interval, 94-100) in the high-flexion mobile-bearing TKA group 12 years after the operation.

CONCLUSION

We found no benefit to mobile-bearing TKA in terms of pain, function, radiographic and CT scan results, and survivorship. Longer-term follow-up is necessary to prove the benefit of the high-flexion mobile-bearing TKA over the high-flexion fixed-bearing TKA.

2017 Chitranjan S. Ranawat Award: Does Computer Navigation in Knee Arthroplasty Improve Functional Outcomes in Young Patients? A Randomized Study

BACKGROUND

Proponents of computer-assisted TKA suggest that better alignment of the TKAs will lead to improved long-term patient functional outcome and survivorship of the implants. However, there is little evidence about whether the improved position and alignment of the knee components obtained using computer navigation improve patient function and the longevity of the TKA.

QUESTIONS/PURPOSES

The purpose of this study was to determine whether (1) clinical results; (2) radiographic and CT scan results; and (3) the survival rate of TKA components would be better in patients having computer-assisted TKA than results of patients having TKA without computer-assisted TKA. In addition, we determined whether (4) complication rates would be less in the patients with computer-assisted TKA than those in patients with conventional TKA.

METHODS

We performed a randomized trial between October 2000 and October 2002 in patients undergoing same-day bilateral TKA; in this trial, one knee was operated on using navigation, and the other knee was operated on without navigation. All 296 patients who underwent same-day bilateral TKA during that period were enrolled. Of those, 282 patients (95%) were accounted for at a mean of 15 years (range, 14-16 years). A total of 79% (223 of 282) were women and the mean age of the patients at the time of index arthroplasty was 59 ± 7 years (range, 48-64 years). Knee Society knee score, WOMAC score, and UCLA activity score were obtained preoperatively and at latest followup. Radiographic measurements were performed including femorotibial angle, position of femoral and tibial components, level of joint line, and posterior condylar offset. Aseptic loosening was defined as a complete radiolucent line > 1 mm in width around any component or migration of any component. Assessors and patients were blind to treatment assignment.

RESULTS

The Knee Society knee (92 ± 8 versus 93 ± 7 points; 95% confidence interval [CI], 92-98; p = 0.461) and function scores (80 ± 11 versus 80 ± 11 points; 95% CI, 73-87; p = 1.000), WOMAC score (14 ± 7 versus 15 ± 8 points; 95% CI, 14-18; p = 0.991), range of knee motion (128° ± 9° versus 127° ± 10°; 95% CI, 100-140; p = 0.780), and UCLA patient activity score (6 versus 6 points; 95% CI, 4-8; p = 1.000) were not different between the two groups at 15 years followup. There were no differences in any radiographic parameters of alignment (on radiography or CT scan) between the two groups. The frequency of aseptic loosening was not different between the two groups (p = 0.918). Kaplan-Meier survivorship of the TKA components was 99% in both groups (95% CI, 93-100) at 15 years as the endpoint of revision or aseptic loosening (p = 0.982). Anterior femoral notching was observed in 11 knees (4%) in the computer-assisted TKA group and none in the conventional TKA group (p = 0.046).

CONCLUSIONS

In this randomized trial, with data presented at a minimum of 14 years of followup, we found no benefit to computer navigation in TKA in terms of pain, function, or survivorship. Unless another study at long-term followup identifies an advantage to survivorship, pain, and function, we do not recommend the widespread use of computer navigation in TKA because of its risks (in this series, we observed femoral notching; others have observed pin site fractures) and attendant costs.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Outcomes of a newer-generation cementless total knee arthroplasty design in patients less than 50 years of age

Background

Younger patients undergoing cemented total knee arthroplasty (TKA) may be at risk for lower implant survivorship and higher revision rates due to the historical increased prevalence of aseptic loosening and instability in this cohort. The recent advances of cementless TKAs may mitigate some of these complications. However, there is a paucity of studies reporting on patients who are under 50 years who have undergone a cementless TKA. Therefore, this study evaluated: (I) implant survivorship; (II) functional outcomes and complications; and (III) radiographic outcomes in patients who were less than 50 years of age and underwent cementless TKA.

Methods

A total of 29 patients (31 knees) younger than 50 years who underwent primary TKA at a single institution (Mount Sinai Beth Israel, New York, New York, USA) from June 2008 to May 2014 were included. Their mean follow-up was 4 years (range, 2 to 6 years). The cohort included 20 women and 9 men who had a mean age of 45 years (range, 34 to 49 years), and a mean body mass index (BMI) of 33 kg/m² (range, 22 to 54 kg/m²). The preoperative knee diagnoses were osteoarthritis (n=24), osteonecrosis (n=5), and rheumatoid arthritis (n=2). A Kaplan-Meier analysis was used to calculate the all cause implant survivorship. Functional outcomes and all complications were recorded for each patient. Additionally, radiographic evaluation using the new Knee Society Radiographic Evaluation and Scoring System was performed.

Results

The overall implant survivorship was 100%; there were no failures or revision surgeries performed as of the latest follow-up visit. At the latest follow-up, the mean Knee Society pain score was 92 points (range, 80 to 95 points) and the mean Knee Society function score was 84 points (range, 70 to 90 points). Additionally, the mean knee extension was 1 degree (range, 0 to 5 degrees) and the mean knee flexion was 125 degrees (range, 95 to 140 degrees). Furthermore, at the latest follow-up, on radiographic evaluation, there was no evidence of component loosening, subsidence, radiolucency, gap formation, or reactive changes, and there were no postoperative complications.

Conclusions

Cementless fixation of TKAs had excellent survivorship and functional and radiographic outcomes at midterm follow-up in patients younger than 50 years. Although longer follow-up is needed, these cementless TKA implants appear to provide promising results in younger patient populations.

Long-term results of total knee arthroplasty in haemophilic patients: an 18-year follow-up

PURPOSE

Total knee arthroplasty (TKA) for patients with end-stage haemophilic arthropathy is considered to be a successful procedure with satisfying mid- to long-term results. It was the purpose of this study to provide clinical and radiological long-term results of TKAs implanted in a consecutive cohort of haemophilic patients.

METHODS

Primary TKA was performed in 43 consecutive knees in 30 haemophilic patients. After a mean of 18 (SD ± 4) years, 15 patients (21 knees) with a mean age of 58 (SD ± 8) years were available for follow-up. The outcome was assessed using the Knee Society score, WOMAC, SF-36, Kaplan-Meier survivorship analysis as well as radiographic evaluation of radiolucency.

RESULTS

In 13 (30%) of the 43 consecutive knees, revision surgery was necessary due to infection or aseptic loosening, among which eight (19%) due to aseptic loosening and five (12%) due to haematogenous infection. The calculated 20-year survival rates with revision for any reason or infection as the end points were 59 and 82%, respectively. All patients with the primary TKA in situ observed progressive radiolucent lines around the implants at the final follow-up. The Knee Society clinical and functional score significantly improved from pre- (36 points; SD ± 16 and 62 points; SD ± 19) to post-operatively (73 points; SD ± 15 and 78 points; SD ± 18; p < 0.001). Eighty-six per cent rated their result as either good or excellent. Whereas flexion did not improve, flexion contracture could be reduced significantly from 18° (SD ± 12) to 6° (SD ± 5; p < 0.001) post-operatively.

CONCLUSION

Total knee arthroplasty in haemophilic patients is associated with high revision, loosening and infection rates after 18 years. However, if revision can be avoided, joint replacement in haemophilic patients helps to relieve pain, achieve higher subjective satisfaction and to restore knee function. Level of evidence IV.

Total Knee Arthroplasty for Osteoarthritis in Patients Less Than Fifty-Five Years of Age: A Systematic Review

BACKGROUND

The proportion of younger patients undergoing total knee arthroplasty (TKA) is increasing and predictions state that the <55 age group will be the fastest growing group by 2030. We aim to collate data across studies to assess functional outcomes following TKA in patients <55 years of age using a systematic review.

METHODS

The search identified 980 studies for title and abstract review. Forty-three full texts were then assessed. Thirteen studies underwent quality assessment and data extraction. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed throughout. Outcomes extracted included pre-operative and post-operative functional scores, range of motion, and patient satisfaction. Clinical complications and survival were also recorded.

RESULTS

Across 13 studies we were able to demonstrate 54-point improvement in clinical Knee Society Score and a 46-point improvement on functional Knee Society Score. A 2.9° improvement in range of motion was found at final follow-up. Satisfaction rate was 85.5%. Cumulative percentage all-cause revision rate was 5.4% across 1283 TKAs at a mean 10.8 years of follow-up. Ten-year survival, for aseptic loosening alone, was 98.2%.

CONCLUSION

TKA is an excellent treatment option for the young osteoarthritic knee with a >50% improvement in functional knee scores. Satisfaction is high and the revision rate remains 0.5% per year.

No difference between cemented and cementless total knee arthroplasty in young patients: a review of the evidence

PURPOSE

The present piece of work provides improved knowledge about the evidence related to TKA in patients 60 years of age or younger, with special focus on fixation methods. Main concern of the review is to analyse the difference of survival rate and complications of cemented and cementless implants.

METHODS

An electronic search was carried out between October and December 2015, through CINAHL, PubMed and the Cochrane Central Registry of Controlled Trials web databases. Articles in English, Italian, French and Spanish were considered for inclusion. Only peer-reviewed studies with adult patients aged 60 years or less, with diagnosis of osteoarthritis in more than 90% of the subjects, were considered for inclusion. All studies had to report outcomes after TKA with either cemented or cementless fixation technique.

RESULTS

No significant differences in terms of clinical, functional and radiological outcomes were found between cemented and cementless implants. Good clinical and functional results were obtained in terms of the Knee Society score and Western Ontario and McMaster Universities Osteoarthritis Index for both techniques. Radiographic results showed that radiolucent lines of <2 mm in width were detected at radiographs, without difference between cemented or cementless implants. Well-conducted trials on cemented versus cementless TKA were carried out in few papers. A survival rate of over 90% was reported in the majority of the studies at a mean follow-up of 8.6 years (range 5-18 years).

CONCLUSION

Similar results were observed in terms of functional outcome and survival rates for both cemented and cementless TKAs. High survival rates were reported for both operative techniques and cemented TKA did not offer additional benefit. Assuming that cementless prosthesis allows a stable fixation and reduces the time of operation, the authors recommend the cementless fixation as a primary choice in the investigated patient population. However, evidence is low, and further research is needed.

LEVEL OF EVIDENCE

IV.

Patient-Reported Outcomes, Quality of Life, and Satisfaction Rates in Young Patients Aged 50 Years or Younger After Total Knee Arthroplasty

BACKGROUND

Recent studies have shown a discrepancy between traditional functional outcomes and patient satisfaction, with some reporting less than 85% satisfaction in older patients undergoing total knee arthroplasty (TKA). As native knee biomechanics are not completely replicated, the resulting functional limitations may cause dissatisfaction in higher-demand individuals. Few studies have recorded patient-reported outcomes, health-related quality of life scores, and patient satisfaction in a young population undergoing TKA.

METHODS

One hundred thirty-six primary TKAs were performed in 114 patients aged 50 years or younger (mean age, 47.0 years; range, 30-50 years) at a single institution. The main diagnoses were osteoarthritis (85%) and rheumatoid arthritis (10%).

RESULTS

The range of motion, Knee Society Score, Oxford Knee Score, and Physical and Mental Component Scores of Short Form-36 increased significantly (P < .001). At 2 years, 85.3% of patients had good/excellent knee scores, 71.3% had good/excellent function scores, 94.9% met the minimal clinically important difference for the Oxford Knee Score, and 84.6% met the minimal clinically important difference for the Physical Component Score. We found that 88.8% of patients were satisfied with their surgeries, whereas 86.8% had their expectations fulfilled. Survivorship using revision as an end point was 97.8% at a mean of 7 years (range, 3-16 years).

CONCLUSION

Patients aged 50 years or younger undergoing TKA can experience significant improvements in their quality of life, have their expectations met, and be satisfied with their surgeries, at rates similar to those of non-age-restricted populations. Surgeons should inform them of these benefits and the potential risk of revision surgery in the future, albeit increasingly shown to be low.

Functional outcome of total knee arthroplasty in patients with haemophilia

INTRODUCTION

Haemophilic arthropathy (HA) is a debilitating complication of haemophilia which leads to TKA in severe cases.

AIM

We conducted a prospective study of the outcome of TKA in our haemophilia cohort to define the outcomes in this population and increase the cost effectiveness of the procedure in our developing country.

METHODS

We reviewed patients with haemophilia who underwent TKA between April 2010 and April 2014. Patients with at least 6 months of follow-up were included. Preoperative knee scores (KSS and WOMAC) and the scores of the quality of life were recorded. Radiographic indices were registered pre- and postoperatively. Any complications were recorded. The patients underwent TKA with medial parapatellar approach. We had a low threshold for quadriceps snip when exposure was difficult. As our routine we did not use suction drains postoperatively.

RESULTS

We included 83 patients (all males, 103 knees). The mean age of the patients was 35.8 years. The mean follow-up period was 45.1 months. Three patients (3.6%) had factor inhibitors. Twenty patients (24.1%) underwent bilateral simultaneous TKA. The mean admission time was 13.87 days. We had two cases of wound infection and one case of haematoma. None of our patients needed transfusion. All knee scores were significantly improved (P < 0.000).

CONCLUSION

Total knee replacement is an effective procedure in treatment of HA. Definition of standards of care for this procedure, which are tailored for resources of a developing country, can have major impact in improving outcomes while maximizing cost effectiveness of this surgery.

Competing Risk of Death When Comparing Tibial Implant Types in Total Knee Arthroplasty

BACKGROUND

In the presence of a competing risk of death, the Kaplan-Meier method is known to overestimate the probability of implant failure. To our knowledge, the magnitude of the competing risk of death in survivorship analyses in total knee arthroplasty has not been studied. The purpose of this study was to determine the extent of the competing risk of death in different age groups during a long-term follow-up of patients who had undergone primary total knee arthroplasty.

METHODS

The study population comprised 22,864 primary total knee arthroplasties at a large medical center in the United States. We compared the overall revision outcomes estimated using the Kaplan-Meier method and the cumulative incidence function over a mean follow-up of 7.8 years (range, 0.1 to 26.3 years).

RESULTS

The risk of death exceeded the risk of revision by a factor of 4 at twelve years following the surgical procedure. The Kaplan-Meier method overestimated the risk of revision by 3% at five years, 14% at ten years, 32% at fifteen years, and 57% at twenty years. At ten years after the surgical procedure, the risk of death exceeded the risk of revision by a factor of 15 in the all-polyethylene group and by a factor of 3.5 in the metal modular group. The Kaplan-Meier method overestimated the ten-year risk of revision by 18% in the all-polyethylene group and by 11% in the metal modular group. After accounting for the higher competing risk of death in the all-polyethylene group, the cumulative incidence of revision in the metal modular group was about 2.5 to three times higher than that in the all-polyethylene group at ten years.

CONCLUSIONS

Although the Kaplan-Meier and cumulative incidence methods yielded different implant survival estimates beyond ten years (Kaplan-Meier overestimates implant failure), the size of the bias was small at earlier time points. The extent of overestimation depends on the duration of follow-up and the magnitude of the competing risk of death.

CLINICAL RELEVANCE

This study examines the clinical relevance of the competing risk of death in total knee arthroplasty.

Long-term results of total knee arthroplasty in young and active patients with posterior stabilized design

BACKGROUND

The aim of this study was to evaluate long-term quality and performance of cemented posterior-stabilized (PS) total knee arthroplasty (TKA) in young and active patients with gap balancing technique.

METHODS

Between January 2000 and October 2001, 55 TKAs (21 rotating platform [RP] and 34 fixed bearing [FB]) in 41 patients, 60 years and younger, with University of California Los Angeles (UCLA) activity score of five and above were included in this study and prospectively followed. Clinical assessments included Western Ontario and McMaster Universities (WOMAC), Knee Society, UCLA activity score, and Patient Administered Questionnaire (PAQ). Radiographic measurements included component positioning, patellar tilt and thickness, radiolucency, loosening or osteolysis.

RESULTS

At a mean follow-up of 12.3±0.5 years (11 to 13), there was no instability, malalignment, or patellofemoral maltracking. Sixty eight percent of patients were still participating in regular recreational activities at the final follow-up. The mean satisfaction score was 9.1±1.9 and 8.5±2.1 in RP-PS and FB-PS groups, respectively. There was no malalignment or osteolysis, no revision for osteolysis or loosening. One patient in the FB-PS group underwent open reduction and internal fixation for a peri-prosthetic fracture. Overall Kaplan-Meier survivorship was 98%.

CONCLUSION

The PS TKA in young and active patients can provide long-term durability and high quality of function.

LEVEL OF EVIDENCE

III.

Instrumented knee joint implants: innovations and promising concepts

This article focuses on in vivo implementations of instrumented knee implants and recent prototypes with highly innovative potential. An in-depth analysis of the evolution of these systems was conducted, including three architectures developed by two research teams for in vivo operation that were implanted in 13 patients. The specifications of their various subsystems: sensor/transducers, power management, communication and processing/control units are presented, and their features are compared. These systems were designed to measure biomechanical quantities to further assist in rehabilitation and physical therapy, to access proper implant placement and joint function and to help predicting aseptic loosening. Five prototype systems that aim to improve their operation, as well as include new abilities, are also featured. They include technology to assist proper ligament tensioning and ensure self-powering. One can conclude that the concept of instrumented active knee implant seems the most promising trend for improving the outcomes of knee replacements.

Development of a cartilage composite utilizing porous tantalum, fibrin, and rabbit chondrocytes for treatment of cartilage defect

Objective

Functional tissue engineering has emerged as a potential means for treatment of cartilage defect. Development of a stable cartilage composite is considered to be a good option. The aim of the study was to observe whether the incorporation of cultured chondrocytes on porous tantalum utilizing fibrin as a cell carrier would promote cartilage tissue formation.

Methods

Rabbit articular chondrocytes were cultured and seeded onto tantalum with fibrin as temporary matrix in a composite, which was divided into three groups. The first group was kept in vitro while a total of 12 constructs were implanted into the dorsum of mice for the second and third groups. The implanted tissues were harvested after 4 weeks (second group) and after 8 weeks (third group). Specific characteristic of cartilage growth were studied by histological and biochemical assessment, immunohistochemistry, and quantitative PCR analysis.

Results

Histological and biochemical evaluation of the formed cartilage using hematoxylin and eosin and Alcian blue staining showed lacunae chondrocytes embedded in the proteoglycan rich matrix. Dimethylmethylene blue assay demonstrated high glycosaminoglycans content in the removed tissue following 8 weeks of implantation. Immunohistochemistry results showed the composites after implantation expressed high collagen type II. Quantitative PCR results confirmed a significant increase in cartilage associated genes expression (collagen type II, AggC, Sox 9) after implantation.

Conclusion

Tantalum scaffold with fibrin as cell carrier promotes chondrocyte proliferation and cartilaginous tissue formation. Producing hyaline cartilage within a stable construct of tantalum and fibrin has a potential for treatment of cartilage defect.

Total knee replacement in young, active patients: long-term follow-up and functional outcome: a concise follow-up of a previous report

Concern exists regarding the long-term durability and effectiveness of total knee arthroplasty in young patients. We reviewed our experience with total knee arthroplasty in patients fifty-five years old and younger with severe osteoarthritis to determine the long-term outcomes. One hundred and fourteen total knee arthroplasties were performed in eighty-eight patients at an average patient age of fifty-one years. Clinical outcomes, survival analysis, and radiographs were all reviewed at the most recent follow-up. One hundred and eight knees (eighty-four patients) were followed up from May 2011 to 2012. At thirty years, survivorship without revision for any cause was 70.1% (twenty-five revisions) and survivorship with failure defined as aseptic revision of the tibial or femoral components was 82.5%. At thirty years, a significant difference existed in the survivorship free from tibial or femoral aseptic revision (p = 0.003) between the non-modular Insall-Burstein I component (92.3%) and the modular Insall-Burstein II component (68.3%). All patients were evaluated at an average time from the index total knee arthroplasty to the latest follow-up of 25.1 years (range, twenty to thirty-five years). Clinical evaluation was obtained in thirty-six patients with forty-five total knee arthroplasties. The average Hospital for Special Surgery score had improved from 57.9 points preoperatively to 85.3 points. The average Knee Society score was 87.4 points and the average Knee Society functional score was 62.1 points; the average knee motion was 110°. The mean Tegner and Lysholm activity score improved from 1.5 points preoperatively to 3.0 points. Radiographic review of forty-two knees that had undergone total knee arthroplasty demonstrated a mean 3.2° of valgus, with no cases of radiographically loose components. Total knee arthroplasty with use of a cemented posterior stabilized system, particularly a non-modular Insall-Burstein I design, was an effective treatment option with durable results for end-stage symptomatic osteoarthritis in this young cohort. These data should provide comparison for modern total knee arthroplasties and alternative procedures in young patients.

Similar survival between screw cementless and cemented tibial components in young patients with osteoarthritis

PURPOSE

The aim of this study was to compare the outcomes of tibial fixation with either a cemented or cementless with screw augmentation component in young patients with non-inflammatory arthritis.

METHODS

Ninety-three patients aged 55 or younger with non-inflammatory arthritis were randomized to compare outcomes between cemented tibial fixation (48 patients) and cementless fixation with screw augmentation (45 patients). The femoral component was cementless in both groups. Post-operative evaluation was assessed by the clinical and radiological criteria of The Knee Society and WOMAC questionnaire.

RESULTS

The median follow-up was 6.7 (5-12) years. Significant differences were found for knee score (p = 0.02), range of motion (p = 0.04), and WOMAC score (p = 0.03). In the cemented group, there was one deep wound infection, four tibial aseptic loosening, and one polyethylene wear, all of which were revised. In the cementless group there was one tibial aseptic loosening and one polyethylene wear, both being revised. There was no difference in revision rate, and the cumulative survival at 9-year for aseptic reason was 93.7 % (95 % CI, 82-100 %) in the cementless group and 90.0 % (95 % CI, 80-100 %) in the cemented group (n.s.).

CONCLUSIONS

Cementless total knee arthroplasty was found to be a reliable option in younger patients with osteoarthritis. Although the revision rate and survival were similar in both groups, better clinical outcomes were obtained with cementless tibial components.

Arthroplasty in young adults: options, techniques, trends, and results

Total knee arthroplasty (TKA) has been established as a very successful and commonly performed procedure for primary and secondary osteoarthritis, and also for inflammatory arthropathies of the knee in all age groups and both genders. It has predominantly been used as a procedure in the age group of patients 65 years and above. Consequently, the literature is replete with data relevant to various issues associated with TKA in the above 65 years age group population. Although there is reasonable clarity and consensus on the broad parameters of the use of TKA in the above 65 years age group (older), this cannot be said for the same issue as relevant to the below 65 years age group (young adults). Over the last 2 decades there has been an increasing tendency toward the use of TKA in young adults, with some countries reporting a 5-fold increase in the last 10 years [1]. The present article is designed to review the most recent literature specific to this subject and assess it vis-à-vis various issues as listed in the subsequent text, with the aim of highlighting evolving thoughts and trends, which could be useful for decision making by clinicians practicing in the community.

Are younger patients undergoing TKAs appropriately characterized as active?

BACKGROUND

The use of TKAs in young patients is increasing. Demographic characteristics and activity levels among this patient group may affect implant selection, performance, and survivorship. Patient age (≤ 55 years) and preoperative diagnosis have been used to define this patient group, with the presumption that these patients are more active than older patients with similar indications for TKA.

QUESTIONS/PURPOSES

We questioned whether (1) demographic features of young patients support high activity expectations after TKA, and (2) preoperative or postoperative functional activity measures support projections that young patients are active after TKA.

METHODS

We retrospectively compared demographic characteristics (gender, BMI, diagnosis) and functional activity profile (as determined by preoperative and postoperative UCLA activity score and functional subscores of The Knee Society and WOMAC instruments) for 150 patients 55 years old or younger (181 TKAs) and 262 patients who were between 65 to 75 years old (314 TKAs) at the time of surgery.

RESULTS

Younger patients having TKAs were significantly more likely than older patients to be female (74% versus 60%, p < 0.001) and to have diagnoses other than osteoarthritis (18% versus 3%, p < 0.001). BMI was significantly greater among younger female patients than among other age and gender combinations (35 kg/m(2) versus 31 kg/m(2), p < 0.001). Male patients had higher mean postoperative UCLA activity scores (5.5 versus 4.4, p < 0.001), Knee Society function subscores (80.2 versus 66.4, p < 0.001), and WOMAC function subscores (82.8 versus 74.2, p < 0.01) compared with female patients, but these were not different in older versus younger patients.

CONCLUSIONS

Sustained high activity levels are not likely to be a principal cause of revision TKAs among younger patients when considering age and diagnosis alone. Determining the effect of activity on survivorship of prosthetic designs and techniques should be based on measured functional activity instead of using age and diagnosis as surrogates for activity.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

The effect of rotating platform TKA on strain distribution and torque transmission on the proximal tibia

Limited experimental data exist comparing the mechanical response of the tibial cortex between fixed and rotating platform (RP) total knee arthroplasty (TKA), particularly in the revision setting. We asked if RP-TKA significantly affects tibiofemoral torque and cortical stain response in both the primary and revision settings. Fixed and RP tibial trays were implanted into analogue tibias and biomechanically tested under axial and torsional loading. Torque and strain response were analyzed using digital image correlation. Fixed bearing designs exhibited 13.8 times greater torque (P<0.01), and 69% (P<0.01) higher cortical strain than RP designs. Strain response was similar in the primary and revision cohorts. The decrease in torque transfer could act as a safeguard to reduce stress, micromotion and torsional fatigue in scenario of poor bone stock.

Cementless and cemented total knee arthroplasty in patients younger than fifty five years. Which is better?

PURPOSE

The purpose of this prospective, randomised study was to evaluate long-term clinical results, radiographic findings, complications and revision and survivorship rates in patients <55 years at a minimum of 16 years after undergoing bilateral, sequential, simultaneous, cemented and cementless total knee arthroplasties (TKAs) in the same patients.

METHODS

Bilateral, sequential, simultaneous TKAs were performed in 80 patients (160 knees). There were 63 women and 17 men with a mean age of 54.3 years (range 49-55), who received a cementless prosthesis in one knee and a cemented prosthesis in the other. The mean follow-up was 16.6 years (range 16-17).

RESULTS

At final review, the mean Knee Society (KS) knee scores (95.8 versus 96.9), Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index (25.4 versus 25.9), range of motion (ROM) (125° versus 128°), patient satisfaction (8.1 versus 8.3) and radiological results were similar in both groups. Femoral component survival rate was 100% in both groups at 17 years; at 17 years, the cemented tibial component survival rate was 100% and the cementless tibial component 98.7%. No osteolysis was identified in either group.

CONCLUSION

Long-term results of both cementless and cemented TKAs were encouraging in patients with OA who were <55 years. However, we found no evidence to prove the superiority of cementless over cemented TKAs.

Haemophilic arthropathy: long-term outcomes in 107 primary total knee arthroplasties

BACKGROUND

Arthropathy of the knee is a frequent complication in patients with severe bleeding disorders leading to considerable pain and disability. Total knee arthroplasty (TKA) provides marked pain relief. However, a modest functional outcome and a high number of complications due to prosthetic infection and loosening are reported. Data on long-term outcomes are scarce, and most case series include few patients. We have studied clinical outcomes and complications of TKAs with special emphasis on prosthetic survival and periprosthetic infection.

METHODS

A consecutive series of 107 TKAs in 74 patients with haemophilic arthropathy were retrospectively reviewed. Follow-up was mean 11.2 years (range 0.8-33.1 years).

RESULTS

Five- and 10-year survival rates, with component removal for any reason as the end point, were 92% and 88%, respectively. Twenty-eight TKAs were removed after median 10 years (range 0.8-28 years). The most common cause of failure was aseptic loosening (14 knees) and periprosthetic infection (seven knees). The overall infection rate was 6.5%. The mean postoperative drop in haemoglobin levels was 4.3 g/dL (range 0.5-9.4) with a significant difference between haemophilia A patients with and without inhibitor (6.3 g/dL (range 3.6-9.4) versus 3.7 g/dL (range 0.5-8.1) (p<0.001). A painless knee was reported in 93% of the TKAs at the latest follow-up.

CONCLUSIONS

The medium and long-term results of primary TKA in a large haemophilic population show good prosthetic survival at five and 10 years with an excellent relief of pain. Periprosthetic infection is still a major concern compared to the non-haemophilic population.

LEVEL OF EVIDENCE

Level IV.

Total knee arthroplasty at 15-17 years: does implant design affect outcome?

Purpose

A study was conducted to compare minimum 15-year survivorship and outcome of the Genesis I and II implants for total knee arthroplasty (TKA).

Methods

We retrospectively reviewed 245 consecutive TKA implanted between January 1995 and October 1997. Genesis I was implanted in 156 knees and Genesis II in 89 knees.

Results

At 15–17 years, 75 patients (31 %) had died, 28 patients (11 %) were lost to follow-up and 11 TKA were revised (4.6 %), including ten Genesis I (6.4 %) and one Genesis II (1.1 %); 131 TKA (53 %) were available for follow-up. Cumulative survivorship was 92.4 % at 15.7 years. Survival in patients <69 years at surgery was lower (88.0 %) compared with patients ≥69 years (98.5 %; p = 0.023). In patients <69 years, Genesis I survival (84.3 %) was worse compared with Genesis II (97.1 %) (p = 0.018). Polyethylene (PE) Insert thickness ≤11 mm had significantly better survivorship (97.1 %) compared with PE >11 mm (56.7 %) (p < 0.0001)

Conclusions

At a minimum of 15 years, the overall (92.4 %) survivorship of Genesis TKA was good, with excellent (98.1 %) survivorship of the Genesis II design. Revision rates were higher with Genesis I in the younger age group and with insert thickness >11 mm, possibly due to longer shelf life of less frequently used sizes.

Five year survival analysis of an oxidised zirconium total knee arthroplasty

BACKGROUND

Zirconium total knee arthroplasties theoretically have a low incidence of failure as they are low friction, hard wearing and hypoallergenic. We report the five year survival of 213 Profix zirconium total knee arthroplasties with a conforming all polyethylene tibial component.

METHODS

Data was collected prospectively and multiple strict end points were used. SF12 and WOMAC scores were recorded pre-operatively, at three months, at twelve months, at 3 years and at 5 years.

RESULTS

Eight patients died and six were "lost to follow-up". The remaining 199 knees were followed up for five years. The mean WOMAC score improved from 56 to 35 and the mean SF12 physical component score improved from 28 to 34. The five year survival for failure due to implant related reasons was 99.5% (95% CI 97.4-100). This was due to one tibial component becoming loose aseptically in year zero.

CONCLUSIONS

Our results demonstrate that the Profix zirconium total knee arthroplasty has a low medium term failure rate comparable to the best implants. Further research is needed to establish if the beneficial properties of zirconium improve long term implant survival.

Anthropometric measurements of the human distal femur: a study of the adult Malay population

The distal femurs of 100 subjects (50 men, 50 women) from the Malay population aged between 19 and 38 years were scanned to measure the anterior-posterior (AP) and medial-lateral (ML) width. The mean AP values were 64.02 ± 3.38 mm and 57.33 ± 3.26 mm for men and women, respectively, and the mean ML values were 74.91 ± 3.52 mm and 64.53 ± 3.07 mm. We compared our data to that published previously for the Chinese and Indian populations. It was found that the Malay population had smaller distal femur than that of the Chinese but was larger than that of the Indian population (P < 0.05). In conclusion, although it is well established that Asians have a smaller distal femur size than that of the Western population, the variations in different Asian ethnicities may need to be considered when designing the appropriate knee implant.

Trabecular metal in total knee arthroplasty associated with higher knee scores: a randomized controlled trial

BACKGROUND

Porous tantalum is an option of cementless fixation for TKA, but there is no randomized comparison with a cemented implant in a mid-term followup.

QUESTIONS/PURPOSES

We asked whether a tibial component fixed by a porous tantalum system might achieve (1) better clinical outcome as reflected by the Knee Society Score (KSS) and WOMAC Osteoarthritis Index, (2) fewer complications and reoperations, and (3) improved radiographic results with respect to aseptic loosening compared with a conventional cemented implant.

METHODS

We randomized 145 patients into two groups, either a porous tantalum cementless tibial component group (Group 1) or cemented conventional tibial component in posterior cruciate retaining TKA group (Group 2). Patients were evaluated preoperatively and 15 days, 6 months, and 5 years after surgery, using the KSS and the WOMAC index. Complications, reoperations, and radiographic failures were tallied.

RESULTS

At 5-year followup the KSS mean was 90.4 (range, 68-100; 95% CI, ± 1.6) for Group 1, and 86.5 (range, 56-99; 95% CI, ± 2.4) for Group 2. The effect size, at 95% CI for the difference between means, was 3.88 ± 2.87. The WOMAC mean was 15.1 (range, 0-51; 95% CI, ± 2.6) for the Group 1, and 19.1 (range, 4-61; 95% CI, ± 2.9) for Group 2. The effect size for WOMAC was -4.0 ± 3.9. There were no differences in the frequency of complications or in aseptic loosening between the two groups.

CONCLUSIONS

Our data suggest there are small differences between the uncemented porous tantalum tibial component and the conventional cemented tibial component. It currently is undetermined whether the differences outweigh the cost of the implant and the results of their long-term performance.

Comparison of cementless and hybrid cemented total knee arthroplasty

Cementless total knee arthroplasty (TKA) implants were designed to provide long-term fixation without the risk of cement-associated complications. The purpose of this study was to evaluate the outcome of titanium-coated cementless implants compared with hybrid TKA implants with a cemented tibial and a cementless femoral component. The authors performed a case-control, single-center study of 120 TKAs performed between 2003 and 2007, including 60 cementless and 60 hybrid cemented TKAs. The authors prospectively analyzed the radiographic and clinical data and the survivorship of the implants at a minimum follow-up of 5 years. Ninety patients who underwent TKA completed the 5-year assessment. Knee Society Scores increased significantly in both groups (P<.001). In both groups, 2 patients underwent revision due to aseptic tibial component loosening, resulting in a 96% implant survival rate. Radiographs showed significantly less radiolucent lines around the tibial baseplate in the cementless group (n=12) than in the hybrid cemented group (n=26) (P=.009).At 6-year mean follow-up, no significant difference existed between the cementless and hybrid cemented tibial components in TKA in terms of clinical and functional results and postoperative complications. The significantly smaller number of radiolucent lines in the cementless group is an indicator of primary stability with the benefit of long-term fixation durability of TKA.

The effects of age on patient-reported outcome measures in total knee replacements

We present a comparison of patient-reported outcomes (PROMs) in relation to patient age, in patients who had received a total (TKR) or unicompartmental knee replacement (UKR). The outcome was evaluated using the Oxford knee score (OKS), EuroQol (EQ-5D) and satisfaction scores. Patients aged 65 to 84 years demonstrated better pre-operative function scores than those aged < 65 years (OKS, p = 0.03; EQ-5D, p = 0.048) and those aged ≥ 85 years (OKS, p = 0.03). Post-operative scores were comparable across age groups, but a linear trend for greater post-operative improvement in OKS and EQ-5D was seen with decreasing age (p < 0.033). The overall mean satisfaction score at six months was 84.9, but those aged < 55 years exhibited a lower mean level of satisfaction (78.3) compared with all other age groups (all p < 0.031). The cumulative overall two-year revision rate was 1.3%. This study demonstrates that good early outcomes, as measured by the OKS and EQ-5D, can be anticipated following knee replacement regardless of the patient's age, although younger patients gain greater improvement. However, the lower satisfaction in those aged < 55 years is a concern, and suggests that outcome is not fully encapsulated by the OKS and EQ-5D evaluation, and raises the question whether the OKS alone is an appropriate measure of pain and function in younger, more active individuals.

Mid term results of LCS knee: The Indian experience

BACKGROUND

The low contact stress rotating platform (LCS RP) knee (DePuy Orthopedics, Inc, Warsaw, Indiana), in use for last four decades in Western population, is reported to have a survival of more than 95% at 15 to 20 years. The reported Indian experience of this knee is limited to 5 years. Our aim was to report the clinical and radiological results of the LCS RP TKA design in the Indian population with a minimum followup of 10 years.

MATERIALS AND METHODS

Fifty-five LCS knees (45 patients) operated between February 1997 and October 2001 were evaluated retrospectively. LCS design was generally selected if the patient was young (≤65 years of age), active and had no severe deformity. There were 40 female (88.9%) and 5 male (11.1%) patients; 47 knees had osteoarthritis (85.5%) and 8 knees had rheumatoid arthritis (14.5%). Knee Society Scores (KSS) and outcome questionnaire were filled at followup and radiographs were analyzed using Knee Society radiographic evaluation and scoring system.

RESULTS

Of 45 patients (55 knees) enrolled, 37 patients (44 knees; 80%) were available for followup at 10 years. Average age was 59.6 years (range 40 to 77). Minimum followup was 10 years (average 12.3 years; range 10 to 15.3 years.). Three knees (6.8%) had been revised, one each for aseptic loosening, bearing dislocation and infection. Mean preoperative KSS of 33 improved to 91 postoperatively. Mean preoperative functional score of 45 improved to 76 postoperatively. Mean preoperative flexion of 113° (90°-140°) reduced to 102° (80°-135°) postoperatively. Erratic femoral rollback and tighter flexion gap to prevent spin out are the probable factors for decreased postoperative range of motion. Five (12%) patients could sit cross-legged and sit on the floor. Anterior knee pain was present in 4.6% (2/44 knees). The survival was 93.2% at 12.3 years. One patient (1.8%) had spin-out of the rotating bearing. No knee had osteolysis or progressive radiolucent lines on X-rays.

CONCLUSION

LCS implant has given good survival (93.2% at 12.3 years) with low rates of spin-out and anterior knee pain and no incidence of osteolysis. Limited flexion post surgery (104°) with only 12% managing to sit cross legged on the floor is a drawback.

Is socioeconomic status a risk factor for stiffness after total knee arthroplasty? A multicenter case-control study

Socioeconomic factors may play a role in the development of arthrofibrosis following total knee arthroplasty. Using manipulation following total knee arthroplasty as a surrogate for stiffness, this multicenter case-control study found that African American and young patients (<45 years of age) had twice the odds for manipulation compared with Caucasian and older-age patients.

Imaging periprosthetic osteolysis around total knee arthroplasties using a human cadaver model

We examined the sensitivity and accuracy of measuring osteolysis around total knee arthroplasty (TKA) on radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) in a cadaver model. Fifty-four simulated osteolytic defects ranging from 0.7 to 14 cm(3) were created in 6 cadaver knees implanted with either a cemented or an uncemented TKA. Three blinded investigators assessed the presence, location, and volume of defects on radiographs and CT and MRI scans with metal reduction protocols. Both CT and MRI had significantly higher sensitivities and specificities than did plain radiographs (P < .005). Overall, there was no difference in the accuracy of defect volume measurements between CT and MRI (P = .574). This study demonstrates the limitations of radiographs and the high sensitivity and specificity of both CT and MRI in assessing osteolysis around TKA.

Update in surgery for osteoarthritis of the knee

Osteoarthritis is a leading cause of disability with incidence and prevalence rising in most nations. Management to address the degenerative joint is stratified according to degree of severity of involvement and always begins with non-surgical modalities before progressing through a range of surgeries, including arthroscopy, osteotomy, unicompartmental and total knee replacement. Predictability of results depends on the type of procedure with total joint replacement giving the most sustainable relief from symptoms, improvement of function and longevity of construct. Obesity is a health priority in developed countries where it is overrepresented in patients presenting for joint replacement. Complications, poor patient satisfaction and joint function can be directly attributable to obesity. Efforts to address obesity should be considered as part of the approach to managing osteoarthritis.

A pre-clinical test platform for the functional evaluation of scaffolds for musculoskeletal defects: the meniscus

In an attempt to delay the progression of osteoarthritis from an index injury, early intervention via repair of injured musculoskeletal soft tissue has been advocated. Despite the development of a number of scaffolds intended to treat soft tissue defects, information about their functional performance is lacking. The goal of this study was to consolidate a suite of in vitro and in vivo models into a pre-clinical test platform to assess the functional performance of meniscal repair scaffolds. Our objective was to assess the ability of a scaffold (Actifit™; Orteq, UK) to carry load without detrimentally abrading against articular cartilage. Three test modules were used to assess the functional performance of meniscal repair scaffolds. The first module tested the ability of the scaffold to carry load in an in vitro model designed to measure the change in normal contact stress magnitude on the tibial plateau of cadaveric knees after scaffold implantation. The second module assessed the in vitro frictional coefficient of the scaffold against cartilage to assess the likelihood that the scaffold would destructively abrade against articular cartilage in vivo. The third module consisted of an assessment of functional performance in vivo by measuring the structure and composition of articular cartilage across the tibial plateau 12 months after scaffold implantation in an ovine model. In vitro, the scaffold improved contact mechanics relative to a partly meniscectomized knee suggesting that, in vivo, less damage would be seen in the scaffold implanted knees vs. partly meniscectomized knees. However, there was no significant difference in the condition of articular cartilage between the two groups. Moreover, in spite of the high coefficient of friction between the scaffold and articular cartilage, there was no significant damage in the articular cartilage underneath the scaffold. The discrepancy between the in vitro and in vivo models was likely influenced by the abundant tissue generated within the scaffold and the unexpected tissue that regenerated within the site of the partial meniscectomy. We are currently augmenting our suite of tests so that we can pre-clinically evaluate the functional performance at time zero and as a function of time after implantation.

What is the evidence for total knee arthroplasty in young patients?: a systematic review of the literature

BACKGROUND

TKA is commonly performed to treat advanced inflammatory and degenerative knee arthritis. With increasing use in younger patients, it is important to define the best practices to enhance clinical performance and implant longevity.

QUESTIONS/PURPOSES

We systematically reviewed the literature to assess: (1) how TKAs perform in young patients; (2) whether the TKA is a durable procedure for young patients, and (3) what guidance the literature outlines for TKA in young patients.

METHODS

We searched the literature between 1950 and 2009 for all studies reporting on TKAs for patients younger than 55 years that documented clinical and radiographic assessments with a minimum 2-year followup. Thirteen studies, reporting on 908 TKAs performed for 671 patients, met these criteria.

RESULTS

Mean Knee Society clinical and functional scores increased by 47 and 37 points, respectively. Implant survivorship was reported between 90.6% and 99% during the first decade and between 85% and 96.5% during the second decade of followup. The literature does not direct specific techniques for TKA for young patients.

CONCLUSIONS

TKA provides surgeon-measured clinical and functional improvements with a moderate increase in second-decade implant failures. Improvements in study design and reporting will be beneficial to guide decisions regarding implant selection and surgical technique.

LEVEL OF EVIDENCE

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

Wear and lysis is the problem in modular TKA in the young OA patient at 10 years

BACKGROUND

Most long-term followup studies of younger patients who underwent TKA include a relatively high percentage of rheumatoid patients, whose function and implant durability may differ from those with osteoarthritis (OA).

QUESTIONS/PURPOSES

The purpose of this study was to evaluate the minimum 10 year followup of TKA performed in more active patients with OA, using modular tibial components, to determine the durability of that construct. Specifically, we determined (1) survivorship; (2) revision rates; (3) functional scores; and (4) rates of radiographic failure at a minimum 10 year followup.

METHODS

We retrospectively reviewed 59 patients (67 knees) with OA who underwent primary total knee arthroplasty with posterior cruciate retaining (27%) or posterior cruciate substituting (73%) components which had modular tibial trays. Patients were evaluated clinically for need of revision and Knee Society, SF-36 and WOMAC scores as well as UCLA and Tegner activity scores. Radiographs were evaluated for loosening and osteolysis. The minimum followup of living patients was 10 years (mean, 12.4 years; range, 10 to 18.4 years). Ten patients (11 knees) died; two patients (2 knees) were lost to followup.

RESULTS

Ten patients (11 knees; 16%) had revisions for aseptic loosening and/or osteolysis. Thirty-one patients (65%) were still performing moderate labor or sports activities. The average UCLA score was 5.5 (range, 2-9). No nonrevised knee demonstrated radiographic loosening.

CONCLUSION

Most patients in this active patient population continued to have acceptable function although 16% underwent revision for wear and/or osteolysis. Isolated tibial insert exchange alone was performed in four of the 11 (36%) revised knees. These data should provide comparison for total knee arthroplasties performed in younger patients with newer designs and newer bearing materials.

LEVEL OF EVIDENCE

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

Total knee arthroplasty in younger patients: a 13-year follow-up study

Total knee arthroplasty (TKA) is a well-established treatment at the end stage of a degenerated knee joint. This operative treatment generally relieves pain, improves physical function, and has a high level of patient satisfaction, especially in the elderly. Younger patients, however, are demanding and have a higher level of physical activity compared to elderly patients. One could therefore expect more mechanical problems such as prosthetic loosening and polyethylene wear after long-term follow-up. The goal of this retrospective cohort study was to determine the survival and long-term results of TKA in young patients. Patients who received a TKA at age 60 years or younger for any reason were included. Minimum follow-up was 10 years. Thirty-nine TKAs (Anatomic Graduate Components; Biomet, Warsaw, Indiana) in 31 patients were included. Average patient age was 52.6 years. There were 3 revisions because of infection; in 1 knee the patella was revised because of aseptic loosening. After an average 13-year follow-up, the survival rate was 89.7% and function scores showed a reasonably functioning TKA. There was no difference in survival rate and function scores between patients with rheumatoid arthritis and those with primary or secondary (posttraumatic) osteoarthritis. Our experience with TKA in a younger patient population has been encouraging. The risk of loosening and wear of the implant in our study is low, and this type of TKA also seems to be an effective and safe treatment for younger patients.

Custom-made lateral femoral condyle replacement for traumatic bone loss: a case report

We report the case of a 24 year-old patient who underwent a novel treatment for a lateral femoral condyle fracture. The fracture was associated with extensive joint line depression and not considered suitable for conventional fixation techniques. Existing reconstructive options for such situations include unicondylar osteoarticular allograft, arthrodesis and arthroplasty. However, these techniques all present significant disadvantages, particularly in the management of active patients. We report our medium-term results following reconstruction using a custom-made lateral femoral condyle hemiarthroplasty replacement. Follow-up at 48 months revealed an excellent, pain-free level of function, with an Oxford Knee Score of 46/48, a Knee Society knee score of 87/100 and a functional score of 100/100. Radiographs demonstrated no evidence of prosthesis loosening or migration and no erosion of the lateral tibial plateau. The technique allows preservation of the remaining normal joint surface of the femur that may promote earlier and better restoration of function. Furthermore, the isolated condyle hemi-replacement maximises bone preservation, facilitating future anticipated revisions. The procedure presents an attractive alternative to other surgical options and their attendant problems. Further investigation into this technique is required before widespread adoption, though such studies will be compromised by the relative rarity of patients in whom the technique is indicated.