ABSTRACT
Identifying and promoting resilience factors may offer novel strategies for optimizing the recovery of patients following orthopedic surgery. Prior research has suggested that self-efficacy, positive affect, vigor, and vitality may function as resilience factors in the face of chronic pain. The present study examines these resilience factors in a prospective, cognitive-affective-behavioral pathway to recovery. Patients (n = 110) undergoing unilateral, total knee replacement surgery completed self-report assessments of study variables. Self-efficacy was assessed 2 ½ weeks prior to surgery, positive affect the day after surgery, vitality and vigor one-month following surgery, and post-operative pain at one- and three-months following surgery. Control variables included gender, pain, and depressive symptoms prior to surgery. Path analysis revealed significant coefficients from pre-operative self-efficacy to positive affect during hospitalization (ß = .246, p = .017), as well as to vitality (ß = .323, p = .001) and vigor (ß = .387, p < .001) at one-month following surgery. Both indicators of energy predicted better post-operative recovery (one-month: vitality ß = -.254, p = .016; vigor ß = -.329, p = .002); three-months: vitality ß = -.192, p = .047, vigor ß = -.201, p = .044). Findings support a cognitive-affective-behavioral pathway to recovery.
Subject(s)
Arthroplasty, Replacement, Knee , Osteoarthritis, Knee , Humans , Osteoarthritis, Knee/surgery , Pain , Postoperative Period , Prospective Studies , Recovery of Function , Self ReportABSTRACT
BACKGROUND: Web-based platforms used to enhance patient-provider communication are being explored to improve patient satisfaction and care delivery, and decrease cost. This study tested a web-based interactive patient-provider software platform (IPSP), JointCOACH, which enabled patient communication with their care team and preparatory/recovery guidance. The aims of this study are to compare (1) patient satisfaction and (2) healthcare resource utilization by patients who underwent total knee and hip replacements and added IPSP to standard of care (SOC). METHODS: This study is a prospective, randomized clinical trial at a single large academic healthcare system. Between May 2018 and March 2020, 399 patients undergoing elective total hip or knee arthroplasty were randomized to SOC arm (n = 204) or SOC + IPSP arm (n = 195). Patient demographics, surgical details, and comorbidities were collected. Patient satisfaction was assessed using Visual Analog Scale and the Picker Patient Experience-15. Healthcare utilization was measured using length of stay, emergency department and office visits, office calls, readmissions, and reoperations at 30 and 90 days after surgery. RESULTS: No difference was found in length of stay between SOC and SOC + IPSP. No differences were found in 30-day or 90-day satisfaction or in healthcare resource utilization (P > .05) including number of office and emergency department visits, phone calls, and readmissions. CONCLUSION: Statistical differences were not found in satisfaction and healthcare utilization with the addition of IPSP to SOC. IPSP can be used to reinforce patient education and communication between the patient and provider, and should be evaluated as an element of virtual care rather than supplementing traditional in-office follow-up. CLINICALTRIALS.GOV: More information on this study can be found at clinicaltrials.gov NCT03499028.
Subject(s)
Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Hospitals , Humans , Internet , Length of Stay , Patient Satisfaction , Prospective Studies , SoftwareSubject(s)
Arthroplasty, Replacement/standards , Outcome Assessment, Health Care/standards , Quality of Health Care , Arthroplasty, Replacement/economics , Arthroplasty, Replacement/statistics & numerical data , Centers for Medicare and Medicaid Services, U.S. , Critical Pathways/standards , Health Care Costs , Humans , Models, Theoretical , Treatment Outcome , United StatesABSTRACT
BACKGROUND: Variability in morphologic features of the human lower extremity within and across populations has been reported, but limb asymmetry within individuals is often overlooked. For example, in 19 studies of version of the lower extremity in the literature, 6 document asymmetry in the population, but none of these reports document asymmetry in an individual. The aim of this study was to identify the (a)symmetry and quantify variability in the tibiae and femora of matched pairs of limbs. More specifically, using a computed tomography scan database tool, we (1) identified (a)symmetry between paired left and right legs for angulation, version, and alignment features and (2) calculated the percentage of paired limbs with >1° of (a)symmetry for each evaluated parameter. METHODS: Computerized axial tomographic scans (<1.0 mm slices) from bilateral lower limbs of 361 skeletally mature subjects without bone pathology were prospectively acquired. Bones were segmented and morphologic features were measured. RESULTS: Angular features are symmetric left to right, but rotational features are not, with 7° of mean asymmetry in femoral anteversion (range: 0°-23°) and 3° of asymmetry in tibial version (range: 0°-8°). CONCLUSIONS: This study disproves the hypothesis that human limbs are absolutely symmetric, confirming instead that there is asymmetry in version between left and right paired limbs. Surgeons strive for symmetry in lower extremity reconstruction, and they often compare side to side in outcome studies, believing that normal limbs are absolutely symmetric when this is not necessarily true. These assumptions concerning lower extremity symmetry need to be reassessed.
Subject(s)
Femur/diagnostic imaging , Lower Extremity/diagnostic imaging , Tibia/diagnostic imaging , Bone Malalignment/diagnostic imaging , Femur/anatomy & histology , Humans , Lower Extremity/anatomy & histology , Observer Variation , Tibia/anatomy & histology , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: The severe pain and disability associated with osteoarthritis often motivate individuals to undergo arthroplastic surgery. However, a significant number of surgical patients continue to experience pain following surgery. Prior research has implicated both the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) in the sensitization of pain receptors and chronic pain conditions. This study uses a prospective, observational, cohort design to examine whether physiological stress responses before and after surgery could predict post-operative pain severity. SUBJECTS: Participants included 110 patients undergoing total knee arthroplasty. METHODS: Physiological indices of stress included the measurement of catecholamine and cortisol levels in 15-hour urine samples collected prior to and 1 month following surgery, as well as in-hospital heart rate and blood pressure (before and after surgery), which were abstracted from medical records. Patients completed the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) [Bellamy et al., J Orthop Rheumatol 1: , 95 (1988)] 2.5 weeks prior to surgery and at a 3-month follow-up. RESULTS: Contrary to expectations, lower stress hormone levels at baseline were related to more severe post-operative pain. Data at later time points, however, supported our hypothesis: cardiovascular tone shortly before surgery and urinary levels of epinephrine 1 month following surgery were positively related to pain severity 3 months later. CONCLUSION: Results suggest that the occurrence of post-operative pain can be predicted on the basis of stress physiology prior to and following arthroplastic surgery.
Subject(s)
Arthroplasty, Replacement, Knee/adverse effects , Pain, Postoperative/diagnosis , Pain, Postoperative/psychology , Severity of Illness Index , Stress, Psychological/diagnosis , Stress, Psychological/psychology , Aged , Aged, 80 and over , Arthroplasty, Replacement, Knee/psychology , Cohort Studies , Female , Humans , Male , Middle Aged , Pain Measurement/methods , Pain, Postoperative/etiology , Predictive Value of Tests , Prospective Studies , Stress, Psychological/complications , Treatment OutcomeABSTRACT
UNLABELLED: Research concerning the impact of trauma history on individuals' ability to cope with subsequent events is mixed. While many studies find that trauma history increases vulnerability for conditions such as post-traumatic stress disorder and chronic pain, others reveal that there are benefits associated with moderate levels of stress (e.g. development of coping skills). OBJECTIVE: The present study investigated whether the experience of prior traumatic stressors would serve as a risk or resilience factor based on physical and emotional outcomes among patients recovering from total knee replacement surgery (TKR). DESIGN: 110 patients undergoing unilateral, TKR completed surveys before surgery, as well as one and three months following the procedure. RESULTS: Contrary to hypotheses, patients who reported more prior traumas experienced less severe pain and functional limitations at one- (ß = -.259, p = .006) and three-month follow-up assessments (ß = -.187, p = .04). A similar pattern emerged when specific types of traumas (e.g. interpersonal) were examined in relation to physical recovery. Further, patients' trauma history was negatively related to symptoms of post-traumatic stress three-months following surgery (e.g. Avoidance: ß = -.200, p = .037). CONCLUSION: Trauma history represents a source of resilience, rather than vulnerability, within the context of arthroplastic surgery.
Subject(s)
Adaptation, Psychological , Arthroplasty, Replacement, Knee/psychology , Resilience, Psychological , Stress, Psychological/psychology , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Risk Factors , Stress Disorders, Post-Traumatic/psychologyABSTRACT
The present studies examine whether information contained in medical records can be used to predict outcomes following two orthopedic procedures: repair of hip fracture and total knee replacement. Study 1 reports the acute, in-hospital recovery data from the medical records of 119 hip fracture patients. Study 2 is a prospective, longitudinal investigation of 3-month postoperative recovery of 110 total knee replacement patients. Patients characterized by a greater number of post-traumatic stress risk factors experienced poorer outcomes following orthopedic surgery. Our results suggest that patients at risk for negative outcomes can be identified by information readily available to medical personnel.
Subject(s)
Arthroplasty, Replacement, Hip/psychology , Arthroplasty, Replacement, Knee/psychology , Recovery of Function , Stress Disorders, Post-Traumatic/etiology , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Prospective Studies , Regression AnalysisABSTRACT
The purpose of this study was to evaluate the longitudinal variations in SF-36 physical and mental scores and the effects of demographics and comorbidities after TKA. This prospective study evaluated 108 men and 173 women who had a mean age of 66 years. All patients were followed for a minimum of five years and SF-36 physical and mental component scores were evaluated longitudinally. Physical scores steadily increased during the first year whereas mental component scores initially decreased in the first six weeks and then subsequently increased and both plateaued at one year. Demographic and social factors had a greater effect on physical component scores and comorbidities were more predictive of poor mental scores. Surgeons should counsel their patients that they will likely perceive the full benefit of TKA by one year, but in the first months may perceive worse outcomes.
Subject(s)
Arthroplasty, Replacement, Knee , Osteoarthritis, Knee/surgery , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/surgery , Comorbidity , Databases, Factual , Female , Health Surveys , Humans , Longitudinal Studies , Male , Middle Aged , Osteonecrosis/surgery , Patient Satisfaction , Prospective StudiesABSTRACT
Total knee arthroplasty (TKA) is a cost-effective procedure used to treat degenerative knee disease with excellent long-term outcomes. However, TKA has not always resulted in excellent functional and patient satisfaction outcomes, partly due to the use of prostheses that did not reproduce natural knee kinematics. Due to a paucity of reports on single-radius designs, the authors evaluated the clinical and patient-reported outcomes of primary TKA in patients who had received a single-radius prosthesis. A total of 287 TKAs from 7 centers were prospectively evaluated. Mean follow-up was 5 years, with each patient undergoing year re-evaluation. Kaplan-Meier implant survivorship was 99.7% at a final follow-up of 7 years. The total reoperation rate was 1.4%. Clinical outcomes demonstrated significant improvements in Knee Society, Short Form 36, and activity scores at a mean follow-up of 5 years. The authors believe that various features of this prosthesis may have contributed to these excellent outcomes. Further longer-term studies are necessary to better evaluate these outcomes.
Subject(s)
Arthroplasty, Replacement, Knee/statistics & numerical data , Knee Prosthesis/statistics & numerical data , Osteoarthritis, Knee/epidemiology , Osteoarthritis, Knee/surgery , Patient Satisfaction/statistics & numerical data , Postoperative Complications/epidemiology , Adult , Aged , Aged, 80 and over , Comorbidity , Equipment Failure Analysis , Female , Fracture Healing , Humans , Male , Middle Aged , Osteoarthritis, Knee/diagnosis , Postoperative Complications/diagnosis , Postoperative Complications/prevention & control , Prevalence , Prosthesis Design , Recovery of Function , Risk Factors , Treatment Outcome , United States/epidemiologyABSTRACT
The present study examined whether in-hospital assessments of heart rate and blood pressure predicted symptoms of post-traumatic stress (PTS) in 110 patients undergoing total knee replacement surgery. After controlling for conceptually relevant factors, in-hospital cardiovascular functioning predicted symptoms of PTS three months following surgery. Specifically, lower pre-surgical and post-surgical systolic and diastolic blood pressure predicted more symptoms of avoidance and PTS (total). In contrast, higher heart rate prior to and shortly following surgery predicted marginally more intrusive thoughts. The present findings suggest that routinely collected medical data may provide a means to identify patients at risk for problematic outcomes following surgery.
Subject(s)
Arthroplasty, Replacement, Knee/psychology , Hospitalization , Predictive Value of Tests , Stress Disorders, Post-Traumatic/etiology , Stress Disorders, Post-Traumatic/physiopathology , Aged , Aged, 80 and over , Blood Pressure/physiology , Female , Heart Rate/physiology , Humans , Male , Medical Audit , Middle Aged , Ohio , Orthopedic Procedures/psychology , Retrospective Studies , Surveys and QuestionnairesABSTRACT
During total hip arthroplasty, the biomechanics of the joint may be altered by removal of bone and by a change in the center of rotation of the joint. Joint pathologies existing at the time of reconstruction may also affect post-operative joint motion. In order to achieve optimized biomechanics of the replaced joint, it is important to understand the muscle actions that are involved in joint movement and the forces that are imposed on the construct by patient activity. To ensure survivorship of the replacement, intraoperative and long-term stability of the components making up the joint within host bone must be achieved. The patients receiving total hip replacements in the twenty first century tend to be younger, heavier, more active and longer lived than the patients who first received hip implants. Thus, biomechanical decisions are becoming even more important for long-term survivorship of the reconstruction.
Subject(s)
Arthroplasty, Replacement, Hip/instrumentation , Arthroplasty, Replacement, Hip/methods , Hip Joint/physiopathology , Hip Joint/surgery , Hip Prosthesis , Muscle Contraction , Muscle, Skeletal/physiopathology , Computer-Aided Design , Femur/physiopathology , Femur/surgery , Humans , Models, Biological , Prosthesis Design , Range of Motion, Articular , Stress, MechanicalABSTRACT
OBJECTIVE: Prior research has suggested that posttraumatic stress symptoms may occur in the context of medical events. Further, these symptoms are often comorbid with conditions associated with pain. Therefore, the current study examined the occurrence of distress following arthroplastic surgery and the relationship of these symptoms to postoperative recovery. METHODS: Patients (N =110) undergoing unilateral, total knee replacement (TKR) surgery were assessed at three time points proximal to their surgery: approximately 2 weeks prior to surgery (T1), 1 month following surgery (T2) and 3 months following surgery (T3). Patients completed survey assessments of recovery outcomes (Western Ontario and McMaster Universities Osteoarthritis Index) and distress (The Impact of Event Scale [IES]) following surgery (T2 and T3). RESULTS: A significant percentage (20%) of patients undergoing TKR reported noteworthy levels of postsurgical stress 1 and 3 months following surgery. Further, this distress was associated with a more difficult recovery following TKR, characterized by more severe pain and greater functional limitations. After controlling for potential confounding variables, regression analyses suggested that postsurgical stress was cross-sectionally related to pain perception and longitudinally predicted subsequent functional limitations and global assessments of recovery. DISCUSSION: To our knowledge, this is the first study to examine postoperative distress (using the IES) following TKR. The present study adds to the growing body of literature documenting the impact of psychological processes on postoperative recovery.
Subject(s)
Arthroplasty, Replacement, Knee/psychology , Depression/psychology , Stress, Psychological/psychology , Adult , Humans , Osteoarthritis, Knee/surgery , Pain Perception , Pain, Postoperative/psychology , Postoperative Period , Surveys and Questionnaires , Treatment OutcomeABSTRACT
The purpose of this article is to review the issues regarding preoperative patient expectations for total knee arthroplasty and whether or not these are fulfilled after surgery. The demographics of the typical total knee arthroplasty patient are changing, and the expectations regarding the outcome of the surgery have been changing as well. Patients are younger, heavier, more active, and often come to the surgeon's office with information provided via the Internet that may be inaccurate and/or misleading. Many expect and assume that the operation will return the knee to "normal." Traditional outcomes measures used by orthopedic surgeons to determine the quality of the results achieved are inadequate and do not take into account the higher expectations of current patients. Various strategies have been developed to improve satisfaction after the surgery. These include preoperative patient education, less invasive surgical approaches, advances in prosthetic design, multimodal pain management, and aggressive postoperative rehabilitation. Using these strategies will make preoperative expectations more realistic and improve postoperative satisfaction.
Subject(s)
Arthroplasty, Replacement, Knee , Outcome Assessment, Health Care , Patient Satisfaction , Arthroplasty, Replacement, Knee/rehabilitation , Humans , Knee Prosthesis , Minimally Invasive Surgical Procedures , Pain, Postoperative/prevention & control , Patient Education as Topic , Physical Therapy Modalities , Postoperative Care , Preoperative Care , Prosthesis DesignABSTRACT
The impact of gender and cortisol levels on depression following planned surgery was examined in 95 men and women. Patients were assessed prior to surgery and at one and three months following surgery. Higher cortisol levels conferred greater risk for depression at one and three months following surgery. This effect was stronger for men than women at one month following surgery, but did not differ between genders at three months post-surgery. Results support a mechanistic role of HPA alterations in depression following a surgical stressor that differs in strength between men and women.
Subject(s)
Arousal/physiology , Arthroplasty, Replacement, Knee/psychology , Depressive Disorder/physiopathology , Hydrocortisone/blood , Hypothalamo-Hypophyseal System/physiopathology , Pituitary-Adrenal System/physiopathology , Postoperative Complications/physiopathology , Adult , Aged , Aged, 80 and over , Depressive Disorder/psychology , Disability Evaluation , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pain Measurement/psychology , Postoperative Complications/psychology , Risk Assessment , Risk Factors , Sex FactorsABSTRACT
OBJECTIVE: The objective was to investigate self-efficacy to manage recovery from surgery and perceptions of the spouse's emotional responsiveness of adults recovering from knee surgery as mediators of the association between the quality of support from the spouse following surgery and recovery outcomes. RESEARCH METHOD: In-person interviews of married older adults (N = 134) with osteoarthritis of the knee who underwent total knee replacement surgery were conducted at 1 month before surgery, 1 month after surgery, and at 3 months after surgery. MAIN OUTCOME MEASURES: Outcomes were knee limitations and depressive symptoms. RESULTS: Self-efficacy mediated the associations between emotional support and problematic support and improvement in knee limitations as well as between emotional support and improvement in depressive symptoms. Perceptions of the spouse's emotional responsiveness did not mediate associations between support and recovery outcomes. CONCLUSIONS: Findings suggest that emotional support from the spouse can improve recovery outcomes in part by strengthening efficacy beliefs to manage recovery, and problematic support can hinder optimal recovery in part by weakening efficacy beliefs.
Subject(s)
Arthroplasty, Replacement, Knee/psychology , Arthroplasty, Replacement, Knee/rehabilitation , Caregivers/psychology , Emotions , Self Efficacy , Social Support , Spouses/psychology , Aged , Aged, 80 and over , Culture , Depression/diagnosis , Depression/psychology , Female , Follow-Up Studies , Humans , Male , Marriage/psychology , Middle Aged , Range of Motion, Articular , Recovery of Function , Self Care/psychology , Sick RoleABSTRACT
Behavioral changes observed following immune system activation are similar to many of the hallmark symptoms of major depressive disorder (MDD), including appetite change, lethargy, fatigue, negative mood and anhedonia. Acute phase proteins, such as interleukin-6 (IL-6) and C-reactive protein (CRP) have been implicated in the production of sickness behavior, and research has revealed significant differences in the levels of these acute phase proteins between depressed and non-depressed individuals. The current study examined whether early post-operative IL-6 and CRP levels predicted subsequent depressive symptoms in 110 patients undergoing total knee replacement surgery (TKR). In-hospital levels of IL-6 and CRP predicted depressive symptoms at three-months following surgery, as indicated by significant main effects and a significant interaction term. Specifically, lower levels of in-hospital CRP and higher levels of IL-6 in-hospital predicted more depressive symptoms three-months following surgery. The finding that levels of acute phase proteins soon after surgery predict subsequent depressive symptoms, if replicated, extends prior research on the relationships between IL-6, CRP, and depression. Further, this predictive relationship suggests the possibility of early identification of individuals at risk for the subsequent development of post-operative depression.
Subject(s)
Arthroplasty, Replacement, Knee/psychology , C-Reactive Protein/metabolism , Depression/metabolism , Interleukin-6/blood , Age Factors , Aged , Aged, 80 and over , Chi-Square Distribution , Depression/psychology , Female , Humans , Male , Middle Aged , Patient Selection , Postoperative Period , Predictive Value of Tests , Quality of Life , Regression Analysis , Sex Factors , Surveys and QuestionnairesABSTRACT
OBJECTIVE: The authors investigated health-related effects of social control (influence) that spouses exert in relation to osteoarthritis patients' medical adherence after total knee replacement surgery. Patients' behavioral and emotional responses to control were examined as mediators of associations between spouses' use of two control strategies (pressure, persuasion) and patients' physical and psychological recovery. DESIGN: The authors used a three-wave panel design with assessments at one month before surgery, 1 month and 3 months after surgery. Data were collected during in-person interviews with 70 married, older adult patients. MAIN OUTCOME MEASURES: Recovery outcomes were assessed as improvement in knee limitations and depressive symptoms at the 3 month follow-up. RESULTS: Spousal pressure and persuasion at one month postsurgery were indirectly associated with patients' recovery outcomes through patients' positive emotional responses to control. CONCLUSION: Although there are often immediate behavioral benefits in response to partners' use of both pressure and persuasion, the long-term health effects of these strategies seem to be accounted for by their opposing links to positive emotions. Findings further refine theory on health-related social control in marriage.
Subject(s)
Coercion , Osteoarthritis/surgery , Patient Compliance , Persuasive Communication , Postoperative Care , Spouses , Aged , Female , Humans , Interpersonal Relations , Male , Surveys and QuestionnairesABSTRACT
The present study examines the reasons cited by 103 patients for their electing to undergo total knee arthroplastic surgery and the relationship between these reasons and their post-operative pain and range of motion. Results suggest that individuals who describe different reasons for undergoing surgery vary in their post-operative recovery. Specifically, patients who cite pain as the reason they are undergoing surgery report greater levels of pain during the early post-operative period. In contrast, patients who describe goals of regaining mobility or a specific activity as their reason for undergoing surgery achieve a greater range of motion during early post-operative physical therapy. Individuals who express avoidance goals for undergoing total knee arthroplasty report more severe post-operative pain at 1 and 3 months following surgery compared to patients who express approach goals. Interventions targeted towards patients reporting pre-operative pain or avoidance goals may decrease subsequent post-operative pain and increase mobility.
Subject(s)
Arthroplasty, Replacement, Knee/psychology , Knee/surgery , Motivation , Pain, Postoperative/psychology , Range of Motion, Articular , Aged , Aged, 80 and over , Analysis of Variance , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pain Measurement , Regression Analysis , Treatment OutcomeABSTRACT
The 4-year outcomes of a prospective study of patients undergoing Triathlon total knee arthroplasty (TKA) are presented. There were 2035 consecutive cemented TKAs performed on 1688 patients. Mean follow-up was 21 months, including 713 knees with a follow-up of > or =2 years. In a subgroup of 239 patients, the coverage of the patella cut surface by the patella component was analyzed. To our knowledge, this is the first article to study this issue. Mean Knee Society pain scores improved from 48 to 96, function improved from 63 to 85, and range of motion improved from a mean of -5 degrees to 104 degrees to a mean of -2 degrees to 126 degrees. Coverage of the patella by the prosthesis was full from medial to lateral in 88% and full from proximal to distal in 91% of knees. The implant system has performed well within the follow-up period, with no implant- or design-related failures.
Subject(s)
Arthritis/surgery , Arthroplasty, Replacement, Knee/instrumentation , Knee Prosthesis , Osteonecrosis/surgery , Prosthesis Design , Adult , Aged , Aged, 80 and over , Arthritis/diagnostic imaging , Arthritis/physiopathology , Female , Femur , Follow-Up Studies , Humans , Male , Middle Aged , Osteonecrosis/diagnostic imaging , Osteonecrosis/physiopathology , Radiography , Range of Motion, Articular , Recovery of Function , Time Factors , Treatment OutcomeABSTRACT
Patient expectations after primary total knee arthroplasty (TKA) continue to increase as the arthroplasty population becomes younger. Patients desire more than just pain relief, function, and the ability to return to higher level activities after TKA. Quadriceps muscle function and strength are critical determinants of this outcome. Many factors, including patient specific issues, surgical technique, and implant design, affect this function after TKA. This article will review our current understanding of quadriceps muscle function after TKA and the factors under the surgeon's control to achieve the best outcome.