Physical Function After Total Knee Replacement: An Observational Study Describing Outcomes in a Small Group of Women From China and the United States.

OBJECTIVE: To describe physical function before and six months after Total Knee Replacement (TKR) in a small sample of women from China and the United States. DESIGN: Observational. SETTING: Community environment. OUTCOMES: Both groups adhered to the Osteoarthritis Research Society International (OARSI) protocols for the 6-minute walk and 30-second chair stand. We compared physical function prior to TKR and 6 months after using linear regression adjusted for covariates. PARTICIPANTS: Women (N=60) after TKR. INTERVENTIONS: Not applicable. RESULTS: Age and body mass index in the China group (n=30; 66y and 27.0kg/m2) were similar to those in the U.S. group (n=30; 65y and 29.6kg/m2). Before surgery, the China group walked 263 (95% confidence interval [CI], -309 to -219) less meters and had 10.2 (95% CI, -11.8 to -8.5) fewer chair stands than the U.S. group. At 6 months when compared with the U.S. group, the China group walked 38 more meters, but this difference did not reach statistical significance (95% CI, -1.6 to 77.4), and had 3.1 (95% CI, -4.4 to -1.7) fewer chair stands. The China group had greater improvement in the 6-minute walk test than did the U.S. group (P<.001). CONCLUSIONS: Despite having worse physical function before TKR, the China group had greater gains in walking endurance and similar gains in repeated chair stands than did the U.S. group after surgery.

Biomechanical Gait Variable Estimation Using Wearable Sensors after Unilateral Total Knee Arthroplasty.

Total knee arthroplasty is a common surgical treatment for end-stage osteoarthritis of the knee. The majority of existing studies that have explored the relationship between recovery and gait biomechanics have been conducted in laboratory settings. However, seamless gait parameter monitoring in real-world conditions may provide a better understanding of recovery post-surgery. The purpose of this study was to estimate kinematic and kinetic gait variables using two ankle-worn wearable sensors in individuals after unilateral total knee arthroplasty. Eighteen subjects at least six months post-unilateral total knee arthroplasty participated in this study. Four biomechanical gait variables were measured using an instrumented split-belt treadmill and motion capture systems. Concurrently, eleven inertial gait variables were extracted from two ankle-worn accelerometers. Subsets of the inertial gait variables for each biomechanical gait variable estimation were statistically selected. Then, hierarchical regressions were created to determine the directional contributions of the inertial gait variables for biomechanical gait variable estimations. Selected inertial gait variables significantly predicted trial-averaged biomechanical gait variables. Moreover, strong directionally-aligned relationships were observed. Wearable-based gait monitoring of multiple and sequential kinetic gait variables in daily life could provide a more accurate understanding of the relationships between movement patterns and recovery from total knee arthroplasty.

Arthrofibrosis Associated With Total Knee Arthroplasty.

BACKGROUND: Arthrofibrosis is a debilitating postoperative complication of total knee arthroplasty (TKA). It is one of the leading causes of hospital readmission and a predominant reason for TKA failure. The prevalence of arthrofibrosis will increase as the annual incidence of TKA in the United States rises into the millions. METHODS: In a narrative review of the literature, the etiology, economic burden, treatment strategies, and future research directions of arthrofibrosis after TKA are examined. RESULTS: Characterized by excessive proliferation of scar tissue during an impaired wound healing response, arthrofibrotic stiffness causes functional deficits in activities of daily living. Postoperative, supervised physiotherapy remains the first line of defense against the development of arthrofibrosis. Also, adjuncts to traditional physiotherapy such as splinting and augmented soft tissue mobilization can be beneficial. The effectiveness of rehabilitation on functional outcomes depends on the appropriate timing, intensity, and progression of the program, accounting for the patient's ability and level of pain. Invasive treatments such as manipulation under anesthesia, debridement, and revision arthroplasty improve range of motion, but can be traumatic and costly. Future studies investigating novel treatments, early diagnosis, and potential preoperative screening for risk of arthrofibrosis will help target those patients who will need additional attention and tailored rehabilitation to improve TKA outcomes. CONCLUSION: Arthrofibrosis is a multi-faceted complication of TKA, and is difficult to treat without an early, tailored, comprehensive rehabilitation program. Understanding the risk factors for its development and the benefits and shortcomings of various interventions are essential to best restore mobility and function.

Association of Psychosocial Factors With Physical Activity and Function After Total Knee Replacement: An Exploratory Study.

OBJECTIVES: To examine the association between self-efficacy, social support, and fear of movement with physical activity and function at baseline and after 12 weeks of physical therapy. DESIGN: Nonrandomized cohort study, repeated-measures design. SETTING: Outpatient rehabilitation clinic within the general community. PARTICIPANTS: Adults (N=49) undergoing outpatient physical therapy for total knee replacement (TKR). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Self-efficacy for exercise (SEE), fear of movement, leisure-time physical activity (LTPA), 6-minute walk test (6MWT), and Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) were assessed at baseline and 12 weeks. RESULTS: Mean functional change scores significantly increased at 12 weeks for the 6MWT (95% confidence interval [CI], 42.3-106.2), KOS-ADLS (95% CI, 12.7-23.3), and LTPA (95% CI, 6.5-26.1). Self-efficacy and fear of movement were not significantly associated with function at baseline or 12 weeks. Participants with lower SEE had 6 fewer metabolic equivalents per week of improvement in LTPA than those with high self-efficacy (95% CI, -27.9 to 14.8), and those with high fear of movement had 26.1m less improvement in the 6MWT than those with low fear of movement (95% CI, -42.2 to 94.5). Most participants reported having no family or peer support for exercise. CONCLUSIONS: Physical therapy for TKR improves physical function and self-reported physical activity. High fear of movement and low SEE may be associated with less improvement in physical activity and function over time.

Quadriceps strength asymmetry predicts loading asymmetry during sit-to-stand task in patients with unilateral total knee arthroplasty.

PURPOSE: This study aimed to examine interlimb differences in muscle strength and sit-to-stand (STS) kinetics in persons who underwent unilateral total knee arthroplasty (TKA) and to determine whether knee pain, quadriceps or hip abductor weakness contributes to altered STS performance. It was hypothesized that the operated limb would have weaker muscles, lower mechanical loading and that operated knee pain and muscle strength symmetry would predict loading symmetry between limbs during STS. METHODS: One hundred and forty-two patients, 6 or 12 months post-unilateral TKA, underwent 3D motion analysis (VICON) of the STS task and isometric strength testing of the quadriceps and hip abductors. Knee pain was also quantified using a question from the Knee Outcome Survey-Activities of Daily Living Scale. RESULTS: The operated limb had weaker quadriceps (P < 0.001), lower hip (P = 0.004) and knee extension moments (P < 0.001), and lower vertical ground reaction forces (P < 0.001). Operated knee pain and quadriceps strength symmetry were related to symmetry in knee extension moment (P < 0.04), and vertical ground reaction forces (P < 0.02) 6 months after surgery, while quadriceps strength symmetry was related to symmetry in vertical ground reaction forces (P = 0.03), 1 year after surgery. CONCLUSION: Patients with unilateral TKA unload the operated limb and shift the mechanical load to the joints of the contralateral limb even 1 year after surgery. Knee pain and quadriceps strength asymmetry may play a role in the asymmetrical loading during STS post-TKA. Clinicians should consider addressing these modifiable impairments to resolve the loading asymmetry. LEVEL OF EVIDENCE: III.

The Effect of Surgical Approach on Strength and Function after Total Hip Arthroplasty.

BACKGROUND: Although total hip arthroplasty (THA) has become standard procedure to manag the symptoms of end-stage osteoarthritis (OA), there are multiple surgical approaches to acceE the hip joint. To date, there is limited information on the effect of surgical approach on muscle strength and performance-based measures of functional ability after THA. QUESTIONS/PURPOSES: The purpose of this study was to compare the effect of posterior or anterolateral surgical approaches on strength and function after THA. We hypothesized that individuals who underwent a posterior approach would have greater strength and performance-based measures of function than individuals who underwent an anterolateral approach one year after surgery. We also hypothesized that there would be no difference in pain or self-reported outcomes at follow-up. METHODS: 63 subjects were tested two to four weeks prior to THA and then three months and 12 months after THA. Subjects were divided into a posterior approach and lateral approac groups. Patients completed functional testing, strength measures, as well as self-reported questionnaires at each time point. Repeated-measures analysis of variance (ANOVA) tests were performed to test the change between the pre-operative and one year time point. Descriptive data were reported for all three time points. RESULTS: There was a significant interaction effect for hip abduction strength (p=0.025) and the lateral group was significantly weaker at one year (p=0.018). No other variable demonstrated a significant interaction effect; however, all other variables with the exception of hip abductor strength (p=0.883) and pain on the non-operated side (p=0.527) demonstrated a significant main effect of time (p≤0.01) in which there was significant improvement at 1 year. CONCLUSION: The lateral surgical approaches result in weaker hip abduction one year after THA; however significant and clinically meaningful improvements in functional ability were seen for most subiects. regardless of surgical approach.

Sit-To-Stand Biomechanics Before and After Total Hip Arthroplasty.

The purpose of this study was to evaluate changes in movement patterns during a sit-to-stand (STS) task before and after total hip arthroplasty (THA), and to compare biomechanical outcomes after THA to a control group. Forty-five subjects who underwent THA and twenty-three healthy control subjects participated in three-dimensional motion analysis. Pre-operatively, subjects exhibited inter-limb movement asymmetries with lower vertical ground reaction force (VGRF) and smaller moments on the operated limb. Although there were significant improvements in movement symmetry 3 months after THA, patients continued to demonstrate lower VGRF and smaller moments on the operated limb compared to non-operated and to control limbs. Future studies should identify the contributions of physical impairments and the influence of surgical approach on STS biomechanics.

Sex differences in patients with different stages of knee osteoarthritis.

OBJECTIVE: To quantify the differences in physical impairments and in performance-based measures and patient-reported outcomes in men and women seeking nonoperative management of symptomatic moderate knee osteoarthritis (OA) and those with symptomatic end-stage knee OA scheduled for total knee arthroplasty compared with healthy controls. DESIGN: Cross-sectional analysis of individuals referred to physical therapy, community participants, and subjects from a 2-year longitudinal study. SETTING: University research department. PARTICIPANTS: Cross-sectional analysis of participants (N=289) consisting of a moderate OA group (n=83), a severe OA group (n=143), and a healthy control group (n=63). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Quadriceps strength, timed Up and Go test, stair-climbing test, 6-minute walk test, Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS), and Physical Component Summary (PCS) of the Medical Outcomes Study 36-Item Short-Form Health Survey. RESULTS: Women had worse scores than men for physical impairment and performance-based measures (P<.001). In the moderate OA group, women had significantly lower KOS-ADLS (P=.007) and PCS (P=.026) scores than men, with no differences seen between sexes in the other 2 groups for patient-reported measures. CONCLUSIONS: Differences between women and men with knee OA on physical impairments and performance-based measures are not echoed in the differences seen in patient-reported measures. These measures signal different domains of knee function in patients with knee OA and should be used as part of a comprehensive functional evaluation.

Simple Mobility Tests Predict Use of Assistive Devices in Older Adults.

BACKGROUND: Assistive devices (ADs) for ambulation are commonly provided to improve safety and independence in older adults. Despite the common use of these devices, there are no standard prescribing guidelines, and non-health care providers, including caregivers and family members, often make decisions about the need for ADs. Identifying factors or a single screening test associated with AD use would benefit clinicians and non-health care caregivers in making decisions to adopt an AD for patients, clients, and family members. PURPOSE/OBJECTIVES: The purpose of this cross-sectional study was to identify the test that best predicts ADs for ambulation and non-AD use among community-dwelling individuals. METHODS: Eighty-five older adults (81.6 ± 8.2 years old) who underwent outpatient physical therapy participated in this study. They participated in a series of tests, including the Timed Up and Go, handgrip and quadriceps strength, the 30-second chair-rise test, the 5-m fast gait speed, the Functional Independence Measure, the locomotive syndrome tests (stand-up test, 2-step test [2ST], and the Locomo-5 Checklist), and numeric pain scales. Mann-Whitney U tests were used to identify differences between those who did and did not use an AD for ambulation. Logistic regression analyses were used to examine which test best predicted AD use. RESULTS: 80% of participants (n = 68) used an AD for ambulation. There were significant differences in all test variables between users and nonusers (P = .033 to P < .001), except for quadriceps strength, age, and pain (all P > .05). Only the 2ST was a significant predictor of AD use, with a cutoff distance of the toe-to-toe stride shorter than 93% of body height (sensitivity: 72%, and specificity: 82%, P = .048). DISCUSSION: Simple functional measures differed between those who did and did not use ADs for ambulation; however, only the 2ST predicted AD status. Individuals who cannot step 93% of their body height may be appropriate for an AD. CONCLUSIONS: If comprehensive clinical evaluations are not available to make decisions about AD use, the 2ST can be used to make clinical recommendations for an AD for ambulation.

Factors Related to Expectations in Individuals Waiting for Total Knee Arthroplasty.

Purpose: There is no consensus on how age and expectations influence planning for total knee arthroplasty (TKA). This study developed and evaluated a new expectation questionnaire and assessed the relationship between preoperative expectations and patient characteristics. Method: The questionnaire evaluated expectations for mobility, pain, participation, and rate of recovery after surgery. Fifty-five participants completed a 6-minute walk test and expectation questionnaire prior to TKA; 17 participants repeated the questionnaire one week later for reliability testing. Analysis of the questionnaire included intra-class correlation coefficient (ICC), homoscedasticity, skewness, kurtosis, multicollinearity, and descriptive measures. A four-step hierarchical linear regression was completed to determine the relationship of patient age, BMI, previous contralateral TKA, and 6-minute walk test scores to expectations. Results: The questionnaire showed good/high test-retest reliability (ICC 0.84; 95% CI: 0.57, 0.94; p > 0.001). The final model was significant in predicting expectation scores R2 = 0.19 (p = 0.017). Conclusions: This questionnaire reliably measures patient expectations before TKA; however, further research is needed. Although we anticipated younger age to be related to higher expectations, higher function prior to TKA appears to be more strongly associated with higher expectations.

Objectif: il n'y a pas de consensus quant à l'influence de l'âge et des attentes sur la planification d'une arthroplastie totale du genou (ATG). La présente étude a porté sur l'élaboration et l'évaluation d'un nouveau questionnaire des attentes et a évalué le lien entre les attentes préopératoires et les caractéristiques des patients. Méthodologie: le questionnaire évaluait les attentes en matière de mobilité, de douleur, de participation et de taux de rétablissement après l'opération. Au total, 55 patients ont effectué un test de marche de six minutes et ont rempli un questionnaire sur leurs attentes avant l'ATG; 17 participants ont rempli de nouveau le questionnaire une semaine plus tard en vue d'un test de fiabilité. L'analyse du questionnaire incluait le coefficient de corrélation intraclasse (CCI), l'homoscédasticité, l'asymétrie, la multicolinéarité et des mesures descriptives. Une régression linéaire hiérarchique en quatre étapes a permis de déterminer la relation entre, d'une part, l'âge des patients, leur indice de masse corporelle, leur ATG contralatérale antérieure et les scores de marche de six minutes et, d'autre part, les attentes. Résultats: le questionnaire avait une fiabilité test-retest bonne à élevée (CCI de 0,84, IC à 95 % de 0,57 à 0,94; p > 0,001). Le modèle définitif pouvait prédire de manière significative les scores d'attentes de R2 = 0,19 (p = 0,017). Conclusions: le présent questionnaire mesure avec fiabilité les attentes des patients avant l'ATG, mais d'autres recherches s'imposent. Les chercheurs croyaient qu'un plus jeune âge serait associé à des attentes plus élevées, mais un meilleur fonctionnement avant l'ATG semblait être lié davantage à des hautes attentes.

Management of a pelvic mass following a worn uncemented total hip arthroplasty.

Intrapelvic granulomatous masses from polyethylene wear debris can easily be misdiagnosed if orthopaedic etiology is not considered. This article presents the case of a 50 year old woman with history of hip joint trauma and total hip arthroplasty (THA) revisions who presented to her gynecologist with a large intrapelvic cyst. Prolonged use of an indwelling drain and failure to recognize the orthopaedic origin of the mass resulted in articular infection that required an antibiotic spacer and subsequent THA revision. This patient did not have pain or evidence of medial wall defects, but did have a history of trauma, revision arthroplasty and acetabular allograft. In the presence of these findings, wear-induced polyethylene debris should be considered in the differential diagnosis of the pelvic mass.

Preoperative predictors for noncopers to pass return to sports criteria after ACL reconstruction.

Less than 50% of athletes pass criteria to return to sports (RTS) 6 months after ACL reconstruction (ACLR). Using data on 38 noncopers, we hypothesized that preoperative age, quadriceps strength index (QI), and knee flexion moments (KFM) during gait would predict the ability to pass/fail RTS criteria and that preoperative quadriceps strength gains would be predictive of passing RTS criteria. Gait analysis and strength data were collected before and after a preoperative intervention and 6 months after ACLR. Age, QI, and KFM each contributed to the predictability to pass or fail RTS criteria 6 months after ACLR. Collectively, the variables predict 69% who would pass and 82% who would fail RTS criteria 6 months after ACLR. Younger athletes who have symmetrical quadriceps strength and greater KFM were more likely to pass RTS criteria. Further, 63% of those who increased preoperative quadriceps strength passed RTS criteria, whereas 73% who did not failed. Increasing quadriceps strength in noncopers before ACLR seems warranted.

Concurrent Validity Between Potential Screening Tests for Early Mobility Decline in Independent Community Dwellers.

BACKGROUND AND PURPOSE: Standardized screening tests that detect early mobility decline, regardless of etiology, are needed for healthy aging. The locomotive syndrome (LS) tests are designed to identify stages of mobility decline and inform appropriate levels of intervention. The long-term goal of this research is to develop standardized mobility screening tests that can be used across health care settings and throughout a patient's lifespan to guide appropriate medical care. As the first step in this process, this study examines the concurrent validity between the reference and the LS tests. METHODS: This cross-sectional study examined correlations between the LS functional tests and a set of reference tests and the ability to differentiate the 3 stages of mobility decline. The reference tests included the stair-climbing test, the 30-second chair rise test, the 6-minute walk test, the Global Physical Health (GPH) portion of the PROMIS, and the Lower Extremity Functional Scale (LEFS). The LS tests included the Stand-Up Test, the 2-Step Test, and the 25-question Geriatric Locomotive Function Scale (25-GLFS). A total of 115 community dwellers of 61.2 years old on average (±10.0 years), with n = 71 (61%) older than 60 years, voluntary participated in this prospective study. Nonparametric analyses of variance and correlations were used to examine the concurrent validity. RESULTS AND DISCUSSION: Performance-based tests were significantly correlated (| r | = 0.38-0.61, P < .001) with LS tests. The LEFS was correlated with all LS tests, but the GPH was only correlated with the 25-GLFS. Also, significant differences were found in reference test scores between the 3 LS stages ( P < .05). CONCLUSIONS: The LS tests and reference tests demonstrated significant correlations, and participants performed significantly worse on reference tests as LS severity increased. Given these results, it is possible that the LS standardized tests may play an important role in mobility screening. Future research should investigate feasibility, sensitivity, and specificity of these tests.

Knee biomechanics and contralateral knee osteoarthritis progression after total knee arthroplasty.

BACKGROUND: Despite the success rate of Total Knee Arthroplasty (TKA), many patients undergo contralateral TKA. It is possible that altered gait mechanics after unilateral TKA play a role in the progression of contralateral OA progression. RESEARCH QUESTION: The purpose of this study was to identify biomechanical predictors of radiographic OA progression in the contralateral (non-surgical) knee after unilateral (primary/initial) TKA. In addition, this study quantified for patients who had contralateral OA progression. METHODS: Biomechanical outcomes were collected 6-24 months after unilateral primary TKA and were used to predict changes in contralateral OA severity at follow-up. Participants were divided into "Progressor" and "Non-Progressor" groups based on changes in Kellgren-Lawrence (KL) OA grade and Joint Space Width (JSW) between baseline and follow-up testing sessions. Biomechanical factors during walking were peak knee adduction moment, knee flexion/extension excursions, knee angle at initial foot contact, and peak knee flexion/extension. Multiple independent t-tests were used to examine the magnitude of differences in biomechanical variables between the groups. Logistic regression was used to examine the association between the biomechanical predictors and change in KL scores and JSW. RESULTS: The mean time between surgery and follow-up x-rays was 8.8 (2.4) years. Of 40 participants, 62.5-78% had contralateral radiographic knee OA progression by follow-up. There were no significant differences in the biomechanical variables between groups. For the regression analysis, none of the biomechanical variables were found to be predictors for contralateral OA progression. SIGNIFICANCE: Although abnormal biomechanics are known risk factors for primary knee OA, it is possible that the mechanisms that result in OA progression of the contralateral limb are different than primary knee OA progression. Future work should evaluate other objective measures of OA progression and determine if cumulative measures of joint loading are related to OA worsening.

Measuring functional improvement after total knee arthroplasty requires both performance-based and patient-report assessments: a longitudinal analysis of outcomes.

The purpose was to explore the responsiveness of both patient-report and performance-based outcome measures to determine functional changes during the acute and long-term postoperative recovery after total knee arthroplasty (TKA). One hundred patients scheduled for unilateral TKA underwent testing preoperatively and at 1 and 12 months postoperatively using the Delaware Osteoarthritis Profile. All physical performance measures decreased initially after surgery then increased in the long term; however, the perceived function did not follow the same trend, and some showed an increase immediately after surgery. Patient-report measures were variable, with no to small response early, but had excellent long-term responsiveness that was twice as large as performance measures. Patient perception fails to capture the acute functional declines after TKA and may overstate the long-term functional improvement with surgery.

Falling risk in patients with end-stage knee osteoarthritis.

Although 25% of patients with end-stage knee osteoarthritis (OA) have reported a fall, there is limited information about risk factors for falling in patients awaiting total knee arthroplasty (TKA). The purpose of this study was to identify clinical and functional measures related to fall risk. A total of 259 participants awaiting TKA for OA participated in this secondary cross-sectional study. Participants were divided into fallers and non-fallers based on falling history in the prior 6 months. Clinical measures (hip and knee pain, neck and low back pain (LBP), knee range of motion, and quadriceps strength) and functional measures (six-minute walk test (6MWT), timed up and go test, and Knee Injury and Osteoarthritis Outcome Score (KOOS)) were assessed in patients 2-4 weeks prior to TKA. Independent t tests were used to examine differences between groups. Odds ratio was calculated to identify clinical risk factors for falling. Of all participants, 47 (18%) reported a fall in the previous 6 months. Fallers had 30% greater LBP (3.0 ± 2.5 vs. 2.1 ± 2.6; p = 0.025). Fallers walked 12% shorter distance in the 6MWT than non-fallers (378 ± 100 vs. 422 ± 105 m; p = 0.010). For every 1-point increase in LBP on a 0-10 scale, there was a 14% greater risk of falling (p = 0.028). For every 10-m increase in 6MWT, there was a 3.8% reduction in fall risk (p = 0.011). Greater LBP and worse walking endurance are associated with falls in individuals with end-stage OA. Future studies should determine if interventions that reduce LBP and improve walking performance also reduce the chance of falling.

Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty.

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post-TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self-reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross-sectionally at 6-24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (ß = .245, p = .044), knee extension moment (ß = .283, p = .049), and knee extension excursion (ß = .298, p = .038). Older age (ß = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (ß = -.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (ß = -.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (ß = .585, p < .001), knee extensor moment (ß = .481, p < .001), and knee flexion excursion (ß = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post-TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post-TKA.

Clinical predictors of elective total joint replacement in persons with end-stage knee osteoarthritis.

BACKGROUND: Arthritis is a leading cause of disability in the United States. Total knee arthroplasty (TKA) has become the gold standard to manage the pain and disability associated with knee osteoarthritis (OA). Although more than 400,000 primary TKA surgeries are performed each year in the United States, not all individuals with knee OA elect to undergo the procedure. No clear consensus exists on criteria to determine who should undergo TKA. The purpose of this study was to determine which clinical factors will predict the decision to undergo TKA in individuals with end-stage knee OA. Knowledge of these factors will aid in clinical decision making for the timing of TKA. METHODS: Functional data from one hundred twenty persons with end-stage knee OA were obtained through a database. All of the individuals complained of knee pain during daily activities and had radiographic evidence of OA. Functional and clinical tests, collectively referred to as the Delaware Osteoarthritis Profile, were completed by a physical therapist. This profile consisted of measuring height, weight, quadriceps strength and active knee range of motion, while functional mobility was assessed using the Timed Up and Go (TUG) test and the Stair Climbing Task (SCT). Self-perceived functional ability was measured using the activities of daily living subscale of the Knee Outcome Survey (KOS-ADLS). A logistic regression model was used to identify variables predictive of TKA use. RESULTS: Forty subjects (33%) underwent TKA within two years of evaluation. These subjects were significantly older and had significantly slower TUG and SCT times (p < 0.05). Persons that underwent TKA were also significantly weaker, had lower self-reported function and had less knee extension than persons who did not undergo TKA. No differences between groups were seen for BMI, gender, knee flexion ROM and unilateral versus bilateral joint disease. Using backward regression, age, knee extension ROM and KOS-ADLS together significantly predicted whether or not a person would undergo TKA (p

Clinical outcomes after simultaneous bilateral total knee arthroplasty: comparison to unilateral total knee arthroplasty and healthy controls.

The purpose of this study was to evaluate the functional outcomes of persons who underwent simultaneous bilateral total knee arthroplasty (TKA) compared to subjects who underwent unilateral TKA and a healthy control group. Fifteen subjects who underwent primary bilateral TKA and 15 sex, age, and body mass index-matched subjects who underwent primary unilateral TKA were observed prospectively for 2 years. Subjects in both surgical groups showed significant improvement in Knee Outcome Scores, Short Form 36 physical component scores, Timed Up and Go, and stair-climbing tasks (P