5- to 18-year follow-up study of cemented total knee arthroplasty for patients 55 years old or younger

Meta-analysis of outcomes after total knee arthroplasty in patients with rheumatoid arthritis and osteoarthritis

The purpose of this study was to compare the difference in functional scores and the incidence of complications after TKA between RA and osteoarthritis. The PubMed, MedLine, The Cochrane Library, Embase and Web of Science databases were searched for all clinical studies up to 15 March 2023 comparing outcomes after total knee replacement in patients with RA and OA, with two review authors independently screening the literature. A total of 7,820,115 (knee-counted) cases were included in 34 studies. The results of meta-analysis showed that the scores of the RA group were lower than that of the osteoarthritis group in the postoperative knee joint score [MD=-2.72,95%CI(-5.06,-0.38),P=0.02] and the postoperative knee joint function score [MD=-11.47,95%CI(-16.55,-6.39),P<0.00001], and the difference was statistically significant. The incidence of deep venous thrombosis (OR=0.84,95%CI(0.79,0.90),P<0.00001) and pulmonary embolism (OR=0.84,95%CI(0.78,0.91),P<0.00001) were significantly lower in RA than in osteoarthritis (P<0.00001). Compared with patients with osteoarthritis, patients with rheumatoid arthritis have lower knee society scores and functional scores after total knee arthroplasty, and a higher risk of prosthetic infection, loosening, and revision, but TKA can still effectively reduce pain in RA patients, Improve function and quality of life without increasing the risk of lower extremity venous thrombosis and pulmonary embolism. Therefore, total knee replacement can be used as a treatment option for patients with rheumatoid arthritis who have not responded to conservative treatment. Patients should fully understand the benefits and possible risks of total knee replacement and develop an individualized treatment plan.

Long-term Results of Partial Release Versus Nonrelease of the Posterior Cruciate Ligament at Cruciate-Retaining Total Knee Arthroplasty: Minimum 15-Year Follow-up

The goal of this study was to compare the clinical and radiologic results of posterior cruciate ligament (PCL) partial release and PCL nonrelease in performing cruciate-retaining total knee arthroplasty (CR-TKA) for a long-term follow-up period of greater than 15 years. A total of 224 patients underwent CR-TKA in our hospital from June 1996 to April 2002 with greater than 15 years of follow-up. We divided the subjects into 2 groups based on release of the PCL. Group 1 was the PCL partial release group (88 cases), and group 2 was the PCL nonrelease group (136 cases). The mean follow-up period was 16.8 years (range, 15.5-19.5 years). We compared the clinical results by measuring the Knee Society Score (KSS), Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) score preoperatively and at the last follow-up. For radiologic results, the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation and Scoring System was used and stress radiographs were obtained at the last follow-up to evaluate PCL function. There was no statistically meaningful difference in radiologic and clinical results between the 2 groups. Radiolucent lines were found for 13 patients radiologically (6 in group 1 and 7 in group 2). No instability as a result of PCL insufficiency required revision surgery on stress radiography at the last follow-up. If an appropriate procedure is performed according to PCL function intraoperatively, CR-TKA can produce a satisfactory result on long-term follow-up. [Orthopedics. 2022;45(4):233-238.].

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.

Effect of Patient Demographics on Minimally Important Difference of Ankle Osteoarthritis Scale Among End-Stage Ankle Arthritis Patients

BACKGROUND

Ankle replacement and ankle arthrodesis are standard treatments for treating end-stage ankle arthritis when conservative treatment fails. Comparing patient-reported outcome scores to the instrument's minimal important difference (MID) helps physicians and researchers infer whether a meaningful change in health from the patient's perspective has occurred following treatment. The objective of this study was to estimate the MID of the Ankle Osteoarthritis Scale among a cohort of operatively treated end-stage ankle arthritis patients undergoing ankle replacement or arthrodesis.

METHODS

A survey package including the Ankle Osteoarthritis Scale was completed by participants preoperatively and 2 years postoperatively. Distribution and anchor-based approaches to calculating the MID were used to estimate the MID of the Ankle Osteoarthritis Scale and its 2 domains. The distribution-based approaches used were the small and medium effect size methods, while the mean absolute change method and linear regression method were the anchor-based approaches. Bootstrap sampling was used to obtain the variance of MID estimates. The MID was estimated for sex, age, operative, and baseline health subgroups. The cohort comprised 283 participants, totaling 298 ankles.

RESULTS

The MID did not vary with sex or operative procedure. Age-based differences in MID values may exist for the Ankle Osteoarthritis Scale total score, and MID values were generally smallest among the oldest patients. Patients with the best and worst ankle-related health preoperatively had higher MID values than patients reporting mid-range Ankle Osteoarthritis Scale values preoperatively.

CONCLUSION

The best estimate of the MID of the Ankle Osteoarthritis Scale total score is 5.81. Our findings indicate that the MID of the Ankle Osteoarthritis Scale may not vary by sex or operative subgroups but likely varies by age and preoperative Ankle Osteoarthritis Scale score.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Total Knee Arthroplasty in Patients Less Than 50 Years of Age: Results at a Mean of 13 Years

BACKGROUND

Patients between 45 and 54 years old will be the fastest-growing cohort seeking total knee arthroplasty (TKA) over the next 15 years. The purpose of this investigation is to determine the clinical outcomes of TKA in patients less than 50 years old at a minimum of 10 years. We hypothesized that this patient population would have a high rate of survivorship that is similar to that of older patients.

METHODS

We reviewed 298 consecutive TKAs on 242 patients at a minimum of 10 years postoperatively. Twenty patients died and 30 TKAs were lost to follow-up leaving 248 TKAs in 202 patients (91 male, 111 female) with a mean age of 45.7 years (range, 26-49) at the time of surgery. Patient-reported outcomes, survivorship, causes of reoperation, and initial postoperative radiographic parameters were collected.

RESULTS

At a mean of 13.0 years, there were 9 revisions for tibial loosening (3.6%), 8 for deep infection (3.2%), 7 for polyethylene wear (2.8%), and 3 for failed ingrowth of a cementless femoral component (1.2%). Kaplan-Meier analysis demonstrated 92.0% survivorship with failures defined as aseptic component revision and 83.9% survivorship for all-cause reoperation at 13 years. Patients with tibial alignment of 4° or more of varus or 10° or more of posterior slope were found to have increased rate of failure.

CONCLUSION

While overall durability was good in this young patient population, tibial fixation and deep infection were relatively common causes of failure. In addition, increased tibial varus and slope were found to increase the rate of failure. Furthermore, the nearly 3% risk of revision for wear suggests that the use of more wear-resistant bearing surfaces may reduce the risk of failure in this patient population.

Effect of Methylprednisolone in Periarticular Infiltration for Primary Total Knee Arthroplasty on Pain and Rehabilitation

BACKGROUND

Optimal pain management after total knee arthroplasty (TKA) is important to ensure timely rehabilitation and patient satisfaction. This study examines the efficacy of adding corticosteroid in periarticular infiltration cocktail with relation to postoperative pain management and rehabilitation in patients undergoing simultaneous bilateral TKA.

METHODS

Fifty patients with symptomatic end-stage bilateral knee osteoarthritis undergoing bilateral TKA under the same anesthetic were recruited. More painful knee was operated first, and the study solution containing ropivacaine, clonidine, epinephrine, and ketorolac with methylprednisolone was infiltrated in one knee and an identical mixture but without methylprednisolone was infiltrated in the second knee. Outcome measures included comparison of visual analogue scale on movement of each knee and range of motion achieved during the first three days after surgery.

RESULTS

Differences in visual analogue scale score and range of motion at day one and three between the two groups of knees were significant (P < .05). Postoperative inflammation and the ability to straight leg raise showed better trends in the knees receiving prednisolone although this did not reach statistical significance.

CONCLUSION

Addition of methylprednisolone to periarticular infiltration cocktail for patients undergoing TKA has significant influence on reduction of pain in the early postoperative period and patients are able to regain knee flexion more quickly.

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.

Nano-carrier based drug delivery systems for sustained antimicrobial agent release from orthopaedic cementous material

Total joint replacement (TJR), such as hip and knee replacement, is a popular procedure worldwide. Prosthetic joint infections (PJI) after this procedure have been widely reported, where treatment of such infections is complex with high cost and prolonged hospital stay. In cemented arthroplasties, the use of antibiotic loaded bone cement (ALBC) is a standard practice for the prophylaxis and treatment of PJI. Recently, the development of bacterial resistance by pathogenic microorganisms against most commonly used antibiotics increased the interest in alternative approaches for antimicrobial delivery systems such as nanotechnology. This review summarizes the efforts made to improve the antimicrobial properties of PMMA bone cements using nanotechnology based antibiotic and non-antibiotic delivery systems to overcome drawbacks of ALBC in the prophylaxis and treatment of PJIs after hip and knee replacement.

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.

Total knee arthroplasty for posttraumatic osteoarthritis in military personnel under age 50

United States military personnel frequently suffer knee injuries. The resulting progressive posttraumatic osteoarthritis (PTOA) causes significant disability in these young high-demand patients for which total knee arthroplasty (TKA) is the only effective treatment of their pain and impairment. Yet the use of this option for treatment of PTOA has not been studied. This retrospective review identified 74 knees in 64 U.S. military personnel who underwent TKA at ≤50 years of age during an 8-year period at a tertiary-care, academic, military medical center. Fifty-five knees (74.3%) experienced one or more prior ligamentous, meniscal, or chondral injuries prior to arthroplasty. Only one subject had a history of osteochondral intra-articular fracture. The average at injury was 29.2 years (95%CI of ±2.50) with an average age at arthroplasty of 44.3 years (±1.11). The most common injury was anterior cruciate ligament rupture (n = 19) with a mean time to TKA of 23.1 (±10.54) and 18.8 years (±7.01) when concomitant meniscal pathology was noted. Nineteen patients were noted to have radiographic and symptomatic end-stage osteoarthritis without a specified etiology at 41.4 years (±1.47) and underwent subsequent TKA. This is the first study to evaluate treatment of end-stage PT OA in young people treated with TKA, finding that the incidence of PTOA as an indication for arthroplasty is significantly higher than among civilians. In this otherwise healthy, high-demand patient population, the rate of OA progression following knee injury is accelerated and the long term implications can be career and life altering. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:677-681, 2017.

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.

Morphometry of femoral rotation for total knee prosthesis according to gender in a Korean population using three-dimensional magnetic resonance imaging

BACKGROUND

We aimed to evaluate differences in femoral arthometric data for 700 osteoarthritic knees (587 females and 113 males) with respect to gender in a Korean population.

METHODS

We identified and measured the mediolateral (ML) and anteroposterior (AP) lengths, femoral aspect ratio (ML/AP), surgical epicondylar axis (SEA), and Whiteside's line (WL). In addition, the anterior, posterior, and distal bone resections of the implanted femurs were evaluated using SEA and WL as references using a three-dimensional analysis method.

RESULTS

ML and AP lengths significantly differed according to gender. ML dimension and aspect ratio were greater in males than in females for a given AP dimension in the femur. No statistically significant differences in femoral rotation with SEA as a reference were observed between male and female knees; however, a significant difference was shown using WL as a reference and both affected the amount of bone resection irrespective of gender.

CONCLUSION

This study provides important guidelines for gender-specific femoral prosthesis design with different ML and AP aspect ratios and femoral rotation based on SEA and WL for Korean populations.

Physicians' perspectives of adopting computer-assisted navigation in orthopedic surgery

OBJECTIVES

Using Computer-assisted orthopedic navigation surgery system (CAOS) has many advantages but is not mandatory to use during an orthopedic surgery. Therefore, opinions obtained from clinical orthopedists with this system are valuable. This paper integrates technology acceptance model and theory of planned behavior to examine the determinants of continued CAOS use to facilitate user management.

METHODS

Opinions from orthopedists who had used a CAOS for at least two years were collected through a cross-sectional survey to verify the research framework. Follow-up interviews with an expert panel based on their experiences of CAOS were conducted to reason the impacts of factors of the research framework.

RESULTS

The results show that factors of "perceived usefulness" and "facilitating condition" determine the intention to continue using CAOS, and "perceived usefulness" was driving by "complexity of task" and "social influence". Additionally, support in practice from high-level managers had an influence on orthopedists' satisfaction after using a CAOS.

CONCLUSIONS

The aging population is accompanied by the increasing requirements for medical care and medical care attendant expenses, especially in total knee replacement. More precision and improvements on survivorship of patients' artificial joints are needed. This study facilitates suggestions in user management when encountering an obstacle in implementing a CAOS. Based on these findings, scientific and practical implications are then discussed.

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.

Functional outcome of knee arthrodesis with a monorail external fixator

Several methods for obtaining knee arthrodesis have been described in the literature and world; over, the commonest cause for arthrodesis is a failed arthroplasty. Less commonly, as in this series, post-infective or traumatic causes may also require a knee fusion wherein arthroplasty may not be indicated. We present salient advantages along with the radiological and functional outcome of twenty four patients treated with a single monorail external fixator. All patients went on develop fusion at an average of 5.4 months with an average limb length discrepancy of 3 cm (1.5-6 cm). Improvements in functional outcome as assessed by the lower extremity functional score (LEFS), and the SF-36 was significant (p = 0.000). Knee arthrodesis with a single monorail external fixator is a reasonable single-staged salvage option in patients wherein arthroplasty may not be the ideal choice. The outcome, though far from ideal, is definitely positive and predictable.

Ten Year Follow-Up of Gap Balanced, Rotating Platform Total Knee Arthroplasty in Patients Under 60 Years of Age

68 patients (91 primary total knee arthroplasties) were evaluated at a mean 10-year, minimum 5 year follow up in patients younger than sixty years of age utilizing the gap balanced, rotating platform design. Follow up assessment included implant survivorship, adverse events, x-rays, Knee Society rating system and clinical evaluation. Three revisions were performed with only one for aseptic loosening at 45 months. Two manipulations were performed in the early postoperative period. Survivorship of the rotating platform, gap balanced knee was 96.7% using surgical revision for any reason and 98.9% using aseptic loosening as endpoints. The rotating platform design using the gap balancing technique in young patients had excellent survivorship at 10-year mean follow up.

Increased risk of failure following revision total knee replacement in patients aged 55 years and younger

The aims of this retrospective study were to compare the mid-term outcomes following revision total knee replacement (TKR) in 76 patients (81 knees) < 55 years of age with those of a matched group of primary TKRs based on age, BMI, gender and comorbid conditions. We report the activity levels, functional scores, rates of revision and complications. Compared with patients undergoing primary TKR, those undergoing revision TKR had less improvement in the mean Knee Society function scores (8.14 (–55 to +60) vs 23.3 points (–40 to +80), p < 0.001), a similar improvement in UCLA activity level (p = 0.52), and similar minor complication rates (16% vs 13%, p = 0.83) at a mean follow-up of 4.6 years (2 to 13.4). Further revision surgery was more common among revised TKRs (17% vs 5%, p = 0.02), with deep infection and instability being the most common reasons for failure. As many as one-third of patients aged < 55 years in the revision group had a complication or failure requiring further surgery.

Young patients undergoing revision TKR should be counselled that they can expect somewhat less improvement and a higher risk of complications than occur after primary TKR.

Cite this article: Bone Joint J 2014; 96-B:1657–62

Revision total knee arthroplasty in the young patient: is there trouble on the horizon?

BACKGROUND

The volume of total knee arthroplasties, including revisions, in young patients is expected to rise. The objective of this study was to compare the reasons for revision and re-revision total knee arthroplasties between younger and older patients, to determine the survivorship of revision total knee arthroplasties, and to identify risk factors associated with failure of revision in patients fifty years of age or younger.

METHODS

Perioperative data were collected for all total knee arthroplasty revisions performed from August 1999 to December 2009. A cohort of eighty-four patients who were fifty years of age or younger and a cohort of eighty-four patients who were sixty to seventy years of age were matched for the date of surgery, sex, and body mass index (BMI). The etiology of failure of the index total knee arthroplasty and all subsequent revision total knee arthroplasties was determined. Kaplan-Meier survival curves were used to evaluate the timing of the primary failure and the survivorship of revision knee procedures. Finally, multivariate Cox regression was used to calculate risk ratios for the influence of age, sex, BMI, and the reason for the initial revision on survival of the revision total knee arthroplasty.

RESULTS

The most common reason for the initial revision was aseptic loosening (27%; 95% confidence interval [CI] = 19% to 38%) in the younger cohort and infection (30%; 95% CI = 21% to 40%) in the older cohort. Of the twenty-five second revisions in younger patients, 32% (95% CI = 17% to 52%) were for infection, whereas 50% (95% CI = 32% to 68%) of the twenty-six second revisions in the older cohort were for infection. Cumulative six-year survival rates were 71.0% (95% CI = 60.7% to 83.0%) and 66.1% (95% CI = 54.5% to 80.2%) for revisions in the younger and older cohorts, respectively. Infection and a BMI of ≥ 40 kg/m(2) posed the greatest risk of failure of revision procedures, with risk ratios of 2.731 (p = 0.006) and 2.934 (p = 0.009), respectively.

CONCLUSIONS

The survivorship of knee revisions in younger patients is a cause of concern, and the higher rates of aseptic failure in these patients may be related to unique demands that they place on the reconstruction. Improvement in implant fixation and treatment of infection when these patients undergo revision total knee arthroplasty is needed.

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.

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.

Total knee arthroplasty considerations in rheumatoid arthritis

The definitive treatment for advanced joint destruction in the late stages of rheumatoid arthritis can be successfully treated with total joint arthroplasty. Total knee arthroplasty has been shown to be a well-proven modality that can provide pain relief and restoration of mobility for those with debilitating knee arthritis. It is important for rheumatologists and orthopedic surgeons alike to share an understanding of the special considerations that must be addressed in this unique population of patients to ensure success in the immediate perioperative and postoperative periods including specific modalities to maximize success.

Outcome and range of motion using a high-flexion cruciate-retaining TKA

Increased knee flexion after total knee arthroplasty (TKA) may contribute to patients' increased satisfaction and more active lifestyles. This study evaluated a TKA component designed for high flexion (more than 125°). The design features an anatomic sagittal femoral radius with short, flared femoral condyles to allow for femoral rollback. Fifty TKA procedures in 47 patients were evaluated prospectively regarding clinical outcomes using Knee Society knee and function scores, Short Form 12 physical component scores, and flexion measured clinically and by digital lateral supine active flexion radiographs. Preoperative and 1-year postoperative radiographs were analyzed by an independent observer. Mean maximum flexion measured clinically was 115° preoperatively and 120° one year postoperatively, with 76% of TKAs achieving more than 120° and 44% achieving more than 125°. Sex, body mass index, and preoperative flexion were not predictors of postoperative flexion. Mean flexion by radiograph was 108° preoperatively and 111° one year postoperatively, with 31% of knees achieving more than 120° and 14% more than 125°. Mean Knee Society knee and function scores and the Short Form 12 physical component scores were 52, 55, and 32 preoperatively, respectively, and 89, 77, and 40 one year postoperatively, respectively. Of the 50 knees, 84% had improvement in their Knee Society function scores, and 76% had improvement in their Short Form 12 physical component scores. The study revealed evidence of increased early postoperative flexion with the use of a cruciate-retaining high-flexion TKA design.

Relationship between patient-based outcome score and conventional objective outcome scales in post-operative total knee arthroplasty patients

PURPOSE

Evaluations for knee osteoarthritis (OA) or post-operative total knee arthroplasty (TKA) have mainly been assessed by objective scales. Though the Knee injury and Osteoarthritis Outcome Score (KOOS) is attracting attention as a patient-based outcome score, the relationship with conventional objective scales after TKA remains controversial. The purpose of this study was to investigate the relationship between KOOS and conventional objective scales and evaluate the features of patient-based outcome scores.

METHODS

Subjects were 130 post-operative patients involving 186 knees treated with TKA. Their mean age was 74.0 ± 8.0 years, and the follow-up period was 43 months. Japanese Orthopaedic Association (JOA) score, original Knee Society Score (KSS) and surgeon's satisfaction score were scored as conventional objective scales besides KOOS. Spearman's correlation coefficient was estimated between these scales. Comparisons between OA and rheumatoid arthritis (RA) as well as primary and revision surgery were performed by the Mann-Whitney U test.

RESULTS

There were strong correlations between KOOS activities of daily living (ADL) and JOA score (r = 0.806), KSS function score (r = 0.803) and between KOOS pain and KSS knee score (r = 0.689). However, there was a poor correlation between KOOS and surgeon's satisfaction score (r = 0.188-0.321). TKA for RA showed poorer results only in KOOS pain (p = 0.003), and revision surgery showed poorer results in KSS function, KOOS symptoms and KOOS quality of life (QOL).

CONCLUSIONS

This study suggested that conventional objective scales reflected mainly ADL disturbances in post-operative TKA patients. Furthermore, patient-based outcome scores made it possible to evaluate and detect a minute change of knee pain and QOL in TKA patients. The Japanese KOOS was a useful tool to evaluate conditions after 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.

[Importance of SPECT/CT for knee and hip joint prostheses]

CLINICAL/METHODICAL ISSUE

Complications, such as loosening or infections are common problems after hip or knee arthroplasty.

STANDARD RADIOLOGICAL METHODS

If conventional X-rays are equivocal bone scintigraphy is the classical second-line imaging modality.

METHODICAL INNOVATIONS

Single photon emission computed tomography/computed tomography (SPECT/CT) offers metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals.

PERFORMANCE

The SPECT/CT procedure is a promising method and is increasingly being used in daily routine to evaluate joint arthroplasty. The additional benefit compared with classical conventional bone scintigraphy has to be evaluated in further prospective studies.

ACHIEVEMENTS

In our hospital SPECT/CT regularly gives important additional information regarding prosthetic joint complications.

PRACTICAL RECOMMENDATIONS

SPECT/CT is increasingly being used as the second step imaging standard modality if conventional X-rays are equivocal.

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.

Ten-year survival of cemented total knee replacement in patients aged less than 55 years

We report the ten-year survival of a cemented total knee replacement (TKR) in patients aged < 55 years at the time of surgery, and compare the functional outcome with that of patients aged > 55 years. The data were collected prospectively and analysed using Kaplan-Meier survival statistics, with revision for any reason, or death, as the endpoint. A total of 203 patients aged < 55 years were identified. Four had moved out of the area and were excluded, leaving a total of 221 TKRs in 199 patients for analysis (101 men and 98 women, mean age 50.6 years (28 to 55)); 171 patients had osteoarthritis and 28 had inflammatory arthritis. Four patients required revision and four died. The ten-year survival using revision as the endpoint was 98.2% (95% confidence interval 94.6 to 99.4). Based on the Oxford knee scores at five and ten years, the rate of dissatisfaction was 18% and 21%, respectively. This was no worse in the patients aged < 55 years than in patients aged > 55 years. These results demonstrate that the cemented PFC Sigma knee has an excellent survival rate in patients aged < 55 ten years post-operatively, with clinical outcomes similar to those of an older group. We conclude that TKR should not be withheld from patients on the basis of age.

Long-term comparison of fixed-bearing and mobile-bearing total knee replacements in patients younger than fifty-one years of age with osteoarthritis

BACKGROUND

There is limited information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in patients with osteoarthritis who are younger than fifty-one years and who have a fixed-bearing implant in one knee and a mobile-bearing implant in the other. The purpose of this study was to compare our long-term clinical and radiographic results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in a group of patients from this population.

METHODS

We prospectively compared the results of 108 patients with osteoarthritis who were younger than fifty-one years (mean age, forty-five years) who had received a fixed-bearing prosthesis in one knee and a rotating platform mobile-bearing prosthesis in the other. The mean follow-up was 16.8 years (range, fifteen to eighteen years). The patients were assessed clinically and radiographically. Knee motion and function were assessed as a primary outcome. Patients were assessed with questionnaires, and each knee was assessed separately.

RESULTS

Although there was significant improvement in both groups of knees, there was no significant difference between the groups (i.e., fixed-bearing and mobile-bearing knees) with regard to the mean postoperative knee motion (126° and 128°, respectively; p = 0.79), the mean Knee Society knee clinical score (95 and 94 points, respectively; p = 0.79), or the Knee Society knee functional score (84 and 85 points, respectively; p = 0.19) at the latest follow-up. In the fixed-bearing group, one knee was revised because of infection, two for aseptic loosening of the tibial component, and two because of wear of the tibial polyethylene insert. In the rotating platform mobile-bearing group, two knees were revised because of instability and one because of infection. The Kaplan-Meier survivorship for revision at 16.8 years of follow-up was 95% (95% confidence interval, 91 to 100) for the fixed-bearing prosthesis and 97% (95% confidence interval, 93 to 100) for the rotating platform mobile-bearing prosthesis.

CONCLUSIONS

Long-term results of both fixed and mobile-bearing total knee arthroplasties were encouraging in patients who were younger than fifty-one years of age with osteoarthritis. However, we found no superiority of the mobile-bearing total knee prosthesis over the fixed-bearing total knee prosthesis.

Total Knee Arthroplasty in Rheumatoid Arthritis

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

Early range of motion of the scorpio non-restrictive geometry cruciate-retaining total knee system

Flexion following total knee arthroplasty in the US population generally falls between 100° and 120°. Because of these relatively low flexion arcs, total knee arthroplasty prosthetic designs emerged allowing "high flexion" (≥125°). We hypothesized that a high-flexion implant design, Scorpio Non-Restrictive Geometry cruciate-retaining knee prosthesis, would allow clinical early maximum flexion of at least 125°. A prospective observational cohort study enrolled 87 unselected patients (94 knees) evaluated preoperation and 3 months and 1 year postoperation for clinical flexion, arc of motion, and Knee Society scores. At 1 year, 67% of knees had improved flexion and 23% achieved flexion of at least 125°. Clinically, flexion improved by 6.9° and total arc of motion improved by 10.6° from preoperation to 1-year postoperation. Although this high-flexion design allows increased flexion, many patients fail to achieve flexion of at least 125°.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Knee arthroplasty in the young patient: survival in a community registry

Operative options for the younger patient with an arthritic knee remain controversial. We prospectively followed 1047 patients 55 years old or younger who underwent knee arthroplasty in a community joint registry over a 14-year period. Patients were implanted with 1047 joints of three predominant designs by 48 surgeons in four hospitals associated with a community joint registry. The mean age for this cohort was 49.8 years, and 62.8% (657/1047) of the patients were female. There were a total of 73 revisions performed, 5.6% (37/653) in women and 9.2% (36/394) in men. Cemented TKAs performed best, with a cumulative revision rate of 15.5%, compared to 32.3% in unicompartmental knee arthroplasty (UKA) patients and 34.1% in cementless designs. Men had a higher cumulative revision rate than women, 31.9% compared to 20.6%. Adjusting for implant type and gender, there was no difference in cumulative revision rate based on diagnosis (OA versus other) or age group (< or = 40, 41-45, 46-50, 51-55 years) or between cruciate-retaining and -substituting designs. Eighty five percent of cemented TKA implants survived at 14 years in the population under 55 years of age in this community registry. Cementless designs and UKA increased revision risk independently.

LEVEL OF EVIDENCE

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

Total knee arthroplasty for isolated patellofemoral arthritis in younger patients

Are the results of total knee arthroplasty for isolated patellofemoral osteoarthritis (OA) in younger patients as good as with patellofemoral arthroplasty? We retrospectively compared the outcomes of 33 TKAs in 27 patients with patellofemoral OA younger than 60 years of age (average, 52 years) to those for a matched group of patients with primarily tibiofemoral arthritis. A cemented posterior cruciate ligament-retaining prosthesis was used in 26 of the 27 knees. We recorded the intraoperative condition of the cartilage. Patients were followed a minimum of 2 years (average, 6.2 years). Average Knee Society knee scores improved from 49 preoperatively to 88 at final followup. Average pain scores from 5 to 44 with 29 knees rated with minimal or no pain; two patients reported anterior knee pain. There were no infections, revisions, reoperations, manipulations, patellar instabilities, patellar fractures, or component loosenings. The results in these patients were as good as those for younger historical control patients undergoing patellofemoral arthroplasty and the complication rates lower. The data were similar to those for our matched group of patients with primarily tibiofemoral OA. We believe our data should raise doubts about the use of patellofemoral arthroplasty in any patient.

LEVEL OF EVIDENCE

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

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.

Total knee arthroplasty in young active patients using a highly congruent fully mobile prosthesis

A consecutive cohort of 63 young patients (80 knees; mean age, 50.7 years) received a Rotaglide mobile knee (Corin Ltd, Cirencester, UK) prosthesis as a primary procedure by a single UK surgeon. Mean follow-up period is 7.3 years (range, 3-12 years). Patients were assessed using the International Knee Society Score and the Oxford Knee Score. Radiolucency was assessed using the Knee Society roentgenographic system. The patients demonstrated an excellent knee and function International Knee Society Score of 98 and 93.6, respectively, with an Oxford Knee Score of 15.5. One knee was revised for traumatic dislocation of the mobile bearing. There were no revisions for aseptic loosening or deep infection. This study demonstrates encouraging midterm results for this device in a young patient cohort.

Total knee arthroplasty effectiveness in patients 55 years old and younger: osteoarthritis vs. rheumatoid arthritis

In the past, total knee arthroplasty, although very successful, was only indicated for an elderly population. Recently though, several papers have been published confirming that total knee arthroplasty is effective in younger patients. This paper supports the results of those papers. In our study, 207 total knee arthroplasties were performed on patients 55 years old and younger using a posterior cruciate-retaining prosthesis. There was an overall survival rate of 97.6% with an average follow-up of 9.1 years. There were some minor variations in the outcome of the operation based on diagnosis (osteoarthritis vs. rheumatoid arthritis). The success also continued over time with an estimated survival rate of 94.8% at 12 years. Total knee arthroplasty is an effective operation in patients younger then 55 years old.

Five- to 12-year follow-up of a hydroxyapatite-coated, cementless total knee replacement in young, active patients

We carried out a prospective study of 118 hydroxyapatite-coated, cementless total knee replacements in patients who were ≤ 55 years of age and who had primary (92; 78%) or post-traumatic (26; 22%) osteoarthritis. The mean period of follow-up was 7.9 years (5 to 12.5). The Knee Society clinical scores improved from a pre-operative mean of 98 (0 to 137) to a mean of 185 (135 to 200) at five years, and 173 (137 to 200) at ten years. There were two revisions of the tibial component because of aseptic loosening, and one case of polyethylene wear requiring further surgery. There was no osteolysis or progressive radiological loosening of any other component. At 12 years, the overall rate of implant survival was 97.5% (excluding exchange of spacer) and 92.1% (including exchange of spacer).

Cementless total knee replacement can achieve excellent long-term results in young, active patients with osteoarthritis. In contrast to total hip replacement, polyethylene wear, osteolysis and loosening of the prosthesis were not major problems for these patients, although it is possible that this observation could change with longer periods of follow-up.

McKeever hemiarthroplasty of the knee in patients less than sixty years old

BACKGROUND

Knee arthritis in the young patient is a challenging problem that may necessitate surgical treatment. We continue to perform hemiarthroplasty with a metallic tibial implant in selected young patients who, for various reasons, are not candidates for osteotomy, unicompartmental arthroplasty, or total knee arthroplasty. The purpose of the present study was to determine the minimum twelve-year results of this procedure in young patients.

METHODS

The original study group consisted of a consecutive series of twenty-four patients (twenty-six knees) who were managed with McKeever tibial hemiarthroplasty for the treatment of unicompartmental osteoarthritis of the knee. All patients were younger than sixty years of age at the time of the index procedure (average age, 44.6 years). During the study period, two patients died and one was lost to follow-up, leaving twenty-one patients (twenty-three knees) available for review. All patients were followed clinically for a minimum of twelve years or until revision. Knee Society knee and functional scores and Tegner scores were determined, and seven of the ten implants were evaluated radiographically.

RESULTS

Thirteen knees were revised at an average of eight years after the index procedures. All thirteen knees had an uncomplicated revision to either a unicompartmental arthroplasty or total knee arthroplasty. Ten retained implants were available for clinical review after an average duration of follow-up of 16.8 years. The mean Knee Society knee scores, functional scores, and Tegner scores, available for nine of these ten knees, were 80, 97, and 4.2, respectively.

CONCLUSIONS

We believe that the McKeever tibial hemiarthroplasty continues to be a reasonable surgical option for patients who are not candidates for osteotomy and are too young or too active for a unicompartmental or total knee arthroplasty.

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

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

Long-term results of 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.

Arthrodesis of the knee

The most common indication for arthrodesis of the knee is an infection at the site of a total knee arthroplasty. Deficiencies in bone stock and poor bone apposition adversely affect the success of a knee arthrodesis. Arthrodesis of the knee can provide a stable, painless extremity for high-functioning patients who are able to walk. Patient function after arthrodesis of the knee is superior to that after above-the-knee amputation. Conversion of a solid knee fusion to a total knee arthroplasty has a substantial complication rate.

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

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

Knee arthroplasty in octogenarians: results at 10 years

The purpose of this study was to assess the long-term results of total knee arthroplasty (TKA) in octogenarians. Between 1976 and 1989, 1 surgeon at our institution performed 110 TKAs in 90 patients who were 80 years of age or older. No patients were lost to follow-up monitoring; all living patients underwent a minimum of 10 years (range, 10-19 years) followup care. There were 5 (3.4%) surgical complications, but at final follow-up examination, no implants had failed because of aseptic loosening. Of all patients, 96% experienced complete pain relief and 91% showed an excellent knee score (> or = 85) at final follow-up examination. Only 14% of patients had an excellent function score. The 88% death rate for our patient population, the fact that only 14% of patients had an excellent function score after surgery, and the lack of aseptic implant failure by the time of final follow-up examination after an average of 8 years with a conventional TKA raise the question of whether using expensive newer-design implants cost-effectiveness is in octogenarians.

What functional activities are important to patients with knee replacements?

There is interest in quantifying the patient's function and mobility after joint replacement. The current study identified activities important to patients having total knee replacement and the prevalence of limitations to participation in these activities. A Total Knee Function Questionnaire consisting of 55 questions addressing the patient's participation in various activities was developed, validated, and mailed to 367 patients at least 1 year after knee replacement. Patients were asked the frequency with which they did each activity, the activity's importance to them, and the extent to which their participation was limited by their knee replacement. The questionnaire was returned by 176 patients, 40% men and 60% women, with an average age of 70.5 years. The most prevalent activities were stretching exercises (73%), leg strengthening exercises (70%), kneeling (58%), and gardening (57%). The activities most important to the patients were stretching exercises (56%), kneeling (52%), and gardening (50%); those most difficult were squatting (75%), kneeling (72%), and gardening (54%). The current study showed a high correlation between the importance of activities and frequency of patient participation confirming that knee replacement successfully restores a significant degree of function. However, after knee replacement, improvements in knee function still are needed to allow patients to do all activities that they consider important.