Clinical Interpretability of Quadriceps Strength and Gait Speed Performance in Total Knee Arthroplasty: A Longitudinal Study.

OBJECTIVE: After a total knee arthroplasty, physical assessments of quadriceps strength and gait speed performance are often undertaken during rehabilitation. Our study aimed to improve their clinical interpretability by examining trajectory curves across levels of self-reported walking and stair climbing function. DESIGN: A sample of 2624 patients with primary total knee arthroplasty participated in this retrospective longitudinal study. Monthly, for 4 mos after surgery, quadriceps strength and gait speed were quantified. At the month-6 time point, self-reported walking and stair climbing function was measured. RESULTS: All physical measures improved nonlinearly over time. In mixed-effects models, greater quadriceps strength and gait speed over time were associated with higher month-6 self-reported walking and stair climbing function ( P < 0.001). Steeper gains in quadriceps strength and gait speed were associated with higher levels of walking and stair-climbing function (interaction P < 0.001). Among female patients who had great difficulty with stair ascent and ambulation, quadriceps strength trajectory curves plateaued after 8 wks after total knee arthroplasty. CONCLUSIONS: By stratifying trajectory curves across clinically interpretable functional levels, our findings potentially provide patients and clinicians a means to better interpret the continuous-scaled quadriceps strength and gait speed values. This information may be valuable when engaging patients in shared decision making and expectation setting. TO CLAIM CME CREDITS: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME. CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Understand how self-reported walking and stair climbing abilities improved from baseline before total knee arthroplasty (total knee arthroplasty) to 6 mos postoperatively; (2) Describe the time course of the 2 performance-based measures of quadriceps strength and walking speed after a total knee arthroplasty; and (3) Relate the trajectories of post-total knee arthroplasty quadriceps strength and walking speed measurements across distinct levels of self-reported walking and stair climbing function. LEVEL: Advanced. ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Machine learning methods are comparable to logistic regression techniques in predicting severe walking limitation following total knee arthroplasty.

PURPOSE: Machine-learning methods are flexible prediction algorithms with potential advantages over conventional regression. This study aimed to use machine learning methods to predict post-total knee arthroplasty (TKA) walking limitation, and to compare their performance with that of logistic regression. METHODS: From the department's clinical registry, a cohort of 4026 patients who underwent elective, primary TKA between July 2013 and July 2017 was identified. Candidate predictors included demographics and preoperative clinical, psychosocial, and outcome measures. The primary outcome was severe walking limitation at 6 months post-TKA, defined as a maximum walk time ≤ 15 min. Eight common regression (logistic, penalized logistic, and ordinal logistic with natural splines) and ensemble machine learning (random forest, extreme gradient boosting, and SuperLearner) methods were implemented to predict the probability of severe walking limitation. Models were compared on discrimination and calibration metrics. RESULTS: At 6 months post-TKA, 13% of patients had severe walking limitation. Machine learning and logistic regression models performed moderately [mean area under the ROC curves (AUC) 0.73-0.75]. Overall, the ordinal logistic regression model performed best while the SuperLearner performed best among machine learning methods, with negligible differences between them (Brier score difference, < 0.001; 95% CI [- 0.0025, 0.002]). CONCLUSIONS: When predicting post-TKA physical function, several machine learning methods did not outperform logistic regression-in particular, ordinal logistic regression that does not assume linearity in its predictors. LEVEL OF EVIDENCE: Prognostic level II.

Satisfaction Rates Are Low following Revision Total Knee Arthroplasty in Asians Despite Improvements in Patient-Reported Outcome Measures.

With the aging population in Asia and increase in total knee arthroplasty (TKA) utilization rates, the number of patients requiring revision TKA (rTKA) are expected to increase as well. The purpose of this study was to evaluate outcomes and satisfaction rates following rTKA in an Asian population that has unique cultural demands. Registry data of patients who underwent rTKA from 2006 to 2010 and had completed 5 years of follow-up were analyzed. Flexion range, Oxford Knee score (OKS), Knee Society score (KSS), the Short-Form 36 (SF-36), and satisfaction rates were assessed for improvement from preoperative values, as well as by the minimum clinically important difference (MCID) criterion. rTKA was performed in 163 patients. There were significant improvements seen at 2 years postoperatively and these were sustained up to 5 years. The minimal clinically important difference (MCID) criterion for KSS, OKS, and SF-36 physical component score (PCS) was met at 2 and 5 years postoperatively. The overall complication rate was 3.7% at a mean follow-up of 8.4 years. A total of 121 patients (74.2%) were satisfied at 5 years postoperatively. Within our cohort, rTKA results in significantly improved patient-reported outcome measures with a low complication rate of 3.7% at a minimum of 5-year follow-up. Despite these encouraging results, satisfaction rates remain low.

Functional outcome and quality of life in patients with hip fracture after total knee arthroplasty.

INTRODUCTION: Hip fractures are a cause of significant morbidity. While rare, ipsilateral hip fractures within 12 months after total knee arthroplasty (TKA) can negatively affect the functional outcome and the quality of life for patients who have had TKA. This aim of this study is to investigate (1) the incidence of hip fracture within 12 months after TKA and (2) the influence of hip fracture after TKA on functional outcome and quality of life in patients. METHODS: Between March 1999 and February 2012, 25 patients who sustained an ipsilateral hip fracture within 12 months after TKA were included in this study. A propensity score matching algorithm was used to select a 1:3 control group without hip fracture. All patients were assessed using the Oxford Knee Score (OKS), Knee Society Function Score (KSFS), Knee Society Knee Score (KSKS), Physical Component Score (PCS) and Mental Component Score (MCS) of SF-36®. RESULTS: The incidence of hip fracture was 0.16% among male patients and 0.20% for female patients. At 24 months after TKA, the OKS was 36 ± 7 in the hip fracture group versus 41 ± 5 in the control group (p = 0.003). The KSFS was 50 ± 24 in the hip fracture group versus 68 ± 21 in the control group (p = 0.001), while the KSKS was 83 ± 12 and 87 ± 8, respectively (p = 0.166). The PCS was 37 ± 12 in the hip fracture group versus 47 ± 11 in the control group (p < 0.001), while the MCS was 55 ± 10 and 54 ± 11, respectively (p = 0.664). CONCLUSION: Although hip fracture during the rehabilitation period after TKA is uncommon, these patients have poorer functional outcome and quality of life. We recommend additional caution against hip fracture after TKA.

Predicting Mobility Limitations in Patients With Total Knee Arthroplasty in the Inpatient Setting.

OBJECTIVE: To develop a prediction model for postoperative day 3 mobility limitations in patients undergoing total knee arthroplasty (TKA). DESIGN: Prospective cohort study. SETTING: Inpatients in a tertiary care hospital. PARTICIPANTS: A sample of patients (N=2300) who underwent primary TKA in 2016-2017. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Candidate predictors included demographic variables and preoperative clinical and psychosocial measures. The outcome of interest was mobility limitations on post-TKA day 3, and this was determined a priori by an ordinal mobility outcome hierarchy based on the type of the gait aids prescribed and the level of physiotherapist assistance provided. To develop the model, we fitted a multivariable proportional odds regression model with bootstrap internal validation. We used a model approximation approach to create a simplified model that approximated predictions from the full model with 95% accuracy. RESULTS: On post-TKA day 3, 11% of patients required both walkers and therapist assistance to ambulate safely. Our prediction model had a concordance index of 0.72 (95% confidence interval, 0.68-0.75) when evaluating these patients. In the simplified model, predictors of greater mobility limitations included older age, greater walking aid support required preoperatively, less preoperative knee flexion range of movement, low-volume surgeon, contralateral knee pain, higher body mass index, non-Chinese race, and greater self-reported walking limitations preoperatively. CONCLUSION: We have developed a prediction model to identify patients who are at risk for mobility limitations in the inpatient setting. When used preoperatively as part of a shared-decision making process, it can potentially influence rehabilitation strategies and facilitate discharge planning.

Predicting individual knee range of motion, knee pain, and walking limitation outcomes following total knee arthroplasty.

Background and purpose - Up to 20% of patients are dissatisfied after total knee arthroplasty (TKA), mainly because of pain and restricted physical function. We developed a prediction model for 6-month knee range of motion, knee pain, and walking limitations in patients undergoing TKA surgery. Patients and methods - We performed a prospective cohort study of 4,026 patients who underwent elective, primary TKA between July 2013 and July 2017. Candidate predictors included demographic, clinical, psychosocial, and preoperative outcome measures. The outcomes of interest were (i) knee extension and flexion range of motion, (ii) knee pain rated on a 5-point ordinal scale, and (iii) self-reported maximum walk time at 6 months post TKA. For each outcome, we fitted a multivariable proportional odds regression model with bootstrap internal validation. Results - At 6 months post TKA, around 5% to 20% of patients had a flexion contracture ³ 10°, range of motion < 90°, moderate to severe knee pain, or a maximum walk time £â€¯15 minutes. The model c-indices (the probabilities to correctly discriminate between 2 patients with different levels of follow-up TKA outcomes) when evaluating these patients were 0.71, 0.79, 0.65, and 0.76, respectively. Each postoperative outcome was strongly influenced by the same outcome measure obtained preoperatively (all p-values < 0.001). Additional statistically significant predictors were age, sex, race, education level, diabetes mellitus, preoperative use of gait aids, contralateral knee pain, and psychological distress (all p-values < 0.001). Interpretation - We have developed models to predict, for individual patients, their likely post-TKA levels of knee extension and flexion range of motion, knee pain, and walking limitations. After external validation, they can potentially be used preoperatively to identify at-risk patients and to help patients set more realistic expectations about surgical outcomes.

Diabetes mellitus does not negatively impact outcomes and satisfaction following unicompartmental knee arthroplasty in well-controlled disease.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) has gained popularity in recent years in view of its minimally invasive nature and proven benefits over the traditional total knee arthroplasty (TKA) in terms of superior knee range of motion and kinametics, faster recovery, lower blood loss, shorter hospital stay and ease of revision with the preservation of bone stock.With the increasing incidence of diabetes mellitus (DM) worldwide and an increased risk of deep infection, wound complications and early failure previously shown in diabetic patients undergoing TKA, it is prudent that we establish the impact of DM on the outcomes and complications of UKA given that there is little on the topic in the current literature.This is especially significant in Asia as Asia is home to more than 60% of the world's population of diabetic patients with estimates of more than 200 million people having the condition. Type 2 DM in particular, is an increasing epidemic with projections to increase by more than 150% between year 2000 and 2035.The purpose of this study is to evaluate the impact of diabetes mellitus on the outcomes and satisfaction of UKA at 2 years postoperatively. We hypothesize that diabetes mellitus does not affect the outcomes and satisfaction following UKA in Asians at 2 years postoperatively. METHODS: We conducted a retrospective review of prospectively collected registry data of 1075 UKAs performed in a multiethnic Asian population between 2006 and 2013 at our institution. Outcomes assessed included flexion range, Knee Society Score (KSS), Oxford Knee Score (OKS), Short-Form 36 (SF-36) and satisfaction scores.All patients with DM were identified and matched with patients without DM for age, gender and body mass index. Outcomes, satisfaction, complication and revision rates were then compared between the two groups up to 2 years postoperatively. Preoperative HbA1c was used to assess the patients' blood glucose control in the DM group. RESULTS: A total of 104 patients (9.7%) had DM, close to the national prevalence (11.3%). At 2 years postoperatively, DM patients had better improvement in their SF-36 Mental Component Score (MCS) (p = 0.015) despite poorer preoperative scores (DM group = 70 ±â€¯23, non-DM group = 77 ±â€¯17, p = 0.013), and were in 1° more varus (p = 0.005) when compared to patients without DM.There was no significant difference in the proportion of patients achieving the minimal clinically important difference for knee-specific outcomes (DM:90%, non-DM:96%) or the satisfaction rates between the groups (DM:92%, non-DM:94%). Complication rates were similar (DM:5.8%, non-DM:4.8%). There were no venous thromboembolic events, deaths or revisions during the follow-up period in both groups. The mean preoperative HbA1c in our DM group was 6.6%. CONCLUSION: In this matched-pair study of diabetic versus non-diabetic patients undergoing surgery for UKA, DM does not have a clinically significant negative impact on the outcomes and satisfaction following UKA in patients with well-controlled disease.

Achieving Minimum Clinically Important Difference in Oxford Knee Score and Short Form-36 Physical Component Summary Is Less Likely with Single-Radius Compared with Multiradius Total Knee Arthroplasty in Asians.

Single-radius (SR) and multiradius (MR) total knee arthroplasties (TKAs) have produced similar outcomes, albeit most studies originate from Western nations. There are known knee kinematic differences between Western and Asian patients after TKA. The aim of this study is to compare the short-term patient-reported outcome measures (PROMs) of SR-TKA versus MR-TKA in Asians. Registry data of 133 SR-TKA versus 363 MR-TKA by a single surgeon were analyzed. Preoperative and 2-year postoperative range of motion (ROM) and PROMs were compared with Student's t-test and Mann-Whitney U-test. Logistic regression model was used to evaluate the odds of SR-TKA or MR-TKA achieving the minimum clinically important difference (MCID) of studied outcomes. Patients in both groups had similar age (65.7 ± 7.6 vs. 65.8 ± 8.2 years; p = 0.317), gender proportion (71% females vs. 79% females; p = 0.119), and ethnic distribution (80% Chinese vs. 84% Chinese; p = 0.258). Preoperatively, there were no statistically significant differences between both groups for ROM, Knee Society Score (KSS), Oxford Knee Score (OKS), and Short Form (SF)-36 scores. At 2 years, all outcomes were statistically similar or failed to achieve a difference of MCID. Controlling for all preoperative variables, SR-TKA has significantly lower odds of achieving MCID for OKS (odds ratio [OR]: 0.275, 95% confidence interval [CI]: 0.114-0.663; p = 0.004) and SF-36 Physical Component Summary (PCS) (OR: 0.547; 95% CI: 0.316-0.946; p = 0.031) compared with MR-TKA. In conclusion, there are no significant differences in the absolute PROMs between SR-TKA and MR-TKA at 2 years following TKA in Asians. However, SR-TKA has significantly lower odds of achieving the MCID for OKS and SF-36 PCS.

Two year outcomes of minimally invasive hallux valgus surgery.

BACKGROUND: We report our experience with the Minimally Invasive Chevron Akin (MICA) technique for correcting hallux valgus, and evaluate its effectiveness and associated complications. METHODS: Case series of 13 feet with mild to moderate symptomatic hallux valgus treated surgically from July 2013 to December 2014, with at least 48-months follow-up. Patients were assessed pre-operatively and post-operatively with radiographical measurements (Hallux Valgus Angle (HVA) and Intermetatarsal Angle (IMA)) and clinical scores (American Orthopaedic Foot and Ankle Society (AOFAS), 36-Item Short Form Health Survery (SF-36), Visual Analog Scale (VAS)). RESULTS: Mean HVA and IMA decreased from 30.4° and 13.9°-10.9° and 10.2° respectively (p<0.05). The mean AOFAS score improved from an average of 59.0-93.7 (p<0.05). All patients reported a VAS score of 0 post-operatively, and the 4 SF-36 domains improved significantly (p<0.05). CONCLUSIONS: The MICA technique is a safe and effective method in the surgical correction of mild to moderate hallux valgus deformity, and continued use is justified.

Pre-existing patellofemoral disease does not affect 10-year survivorship in fixed bearing unicompartmental knee arthroplasty.

PURPOSE: The purpose of this study was to assess 10-year functional outcome and survivorship analysis of patients with significant radiographic evidence of patellofemoral joint arthritis treated with fixed bearing unicompartmental knee arthroplasty. METHODS: Two hundred and sixteen patients (263 knees) that underwent UKA from 2003 to 2005 for a mean of 10.5 ± 2.1 years were prospectively followed up. Preoperative radiological assessment of the patellofemoral joint state was assessed according to the Ahlback classification by an independent assessor and radiographically significant patellofemoral disease was defined as grade 2 or more. Patients with significant bone-on-bone contact in the patellofemoral joint were excluded. RESULTS: Of the 263 knees, 222 (84.4%) had normal patellofemoral joint state and 41 (15.6%) radiologically significant patellofemoral disease. At 10 years' follow-up, the normal and patellofemoral groups had similar OKS (20 ± 7 vs 20 ± 8, n.s.) and KSS scores (79 ± 20 vs 81 ± 20, n.s.), respectively. There were 12 revision surgeries in the normal group and the most common indication for revision was progression of contralateral compartment osteoarthritis (6 of 12 cases). There was only one revision in the patellofemoral group and it was due to progression of contralateral compartment osteoarthritis (n.s.). When all secondary surgeries to the operated knee were considered as failures, the 10-year survival rate was 95.1% (CI 95%: 92.2-97.7%). CONCLUSION: The presence of significant preoperative radiological patellofemoral disease does not affect long-term implant survival and patients have excellent functional outcomes 10 years postoperatively. These patients should not be contraindicated from undergoing unicompartmental knee arthroplasty. LEVEL OF EVIDENCE: III.

Clinical and Functional Outcomes: Primary Constrained Condylar Knee Arthroplasty Compared With Posterior Stabilized Knee Arthroplasty.

INTRODUCTION: Constrained condylar knee (CCK) prostheses are commonly used in difficult primary total knee arthroplasty and revision total knee arthroplasty. We postulate that the use of CCK prostheses in primary knee arthroplasty may result in decreased range of motion but with better patient-reported functional scores compared with primary posterior stabilized (PS) knee prostheses because of increased varus and valgus stability from increased constraint. METHODS: We conducted a case-control study using prospectively collected data on functional outcome scores and range of motion preoperatively and at 6 months and at 2 years. Thirty-eight patients with primary CCK arthroplasty were matched with 38 patients with primary PS knee arthroplasty treated by a single surgeon. Institutional review board approval was obtained. Analysis was done using the independent t-test. RESULTS: Total 76 patients with 61 (80.3%) female patients, 30 (39.5%) left knees, and 9 (11.8%) valgus knees. There was no significant difference in preoperative age (CCK arthroplasty 70.7 ± 6.0 years versus PS knee arthroplasty 68.5 ± 5.2 years; P < 0.085), body mass index (27.2 ± 4.4 versus 26.3 ± 5.2; P < 0.44), Oxford Knee Score (35.8 ± 7.8 versus 36.0 ± 7.6; P < 0.92), and Medical Outcomes Study 12-Item Short Form (SF-36) scores and knee extension (8.0° ± 6.7° versus 7.7° ± 7.6°; P < 0.84). There was no significant difference in preoperative knee flexion (106.0° ± 22.9° versus 117.3° ± 20.1°; P < 0.026). There was no significant difference in 6-month knee extension (4.5° ± 6.8° versus 4.1° ± 4.5°; P < 0.80), knee flexion (110.5° ± 15.8° versus 110.9° ± 15.5°; P < 0.92), Oxford Knee Score (18.9° ± 3.4° versus 20.1° ± 5.3°; P < 0.27), and SF-36 scores. There was no significant difference in 2-year knee extension (1.8° ± 5.7° versus 1.5° ± 4.0°; P < 0.82), knee flexion (111.3° ± 13.6° versus 115.0° ± 16.5°; P < 0.30), Oxford Knee Score (18.5° ± 3.7° versus 18.2° ± 4.2°; P < 0.77), and SF-36 scores. CONCLUSION: The use of CCK prostheses in primary knee arthroplasty gives similar clinical and functional outcomes at 2 years as those of PS knee prostheses, despite increased constraint.

Acceptable Functional Outcomes and Patient Satisfaction Following Total Knee Arthroplasty in Asians with Severe Knee Stiffness: A Matched Analysis.

BACKGROUND: This study evaluated outcomes following total knee arthroplasty for severely stiff knees in Asians. METHODS: Registry data of patients undergoing primary total knee arthroplasty between 2004 and 2013 were collected and retrospectively reviewed. Sociodemographic and anthropometric data together with the Oxford Knee Score and the Knee Society Score (Knee Society Knee Score and the Knee Society Function Score) were collected both preoperatively and postoperatively for up to 2 years. Case subjects consisted of patients with a preoperative flexion range of ≤ 20°. Control subjects consisted of patients with a preoperative flexion range of > 90°. Patients were matched for age, sex, and all preoperative scores in a 2:1 fashion. Two-year outcomes and 5-year revision rates were then compared between cases and controls. RESULTS: There were 28 cases and 56 controls. Cases had a significantly lower body mass index than the controls (p = 0.003) and had a longer hospital stay (p < 0.0001). At 2 years, cases had a significantly lower flexion range (p < 0.001) and a lower Knee Society Function Score (p = 0.020) than the controls. Cases had a significantly greater improvement in the flexion range (p < 0.001) postoperatively than controls. The mean change in functional outcomes at 2 years was comparable between the two groups. Seventy-one percent of the cases and 88% of controls were satisfied. There was a significant difference in the 5-year revision rate (10% vs 0%, p = 0.013). More cases were discharged to a rehabilitation facility compared to controls (p = 0.011). There were no differences in inpatient complication rates. CONCLUSIONS: Functional outcomes and patient satisfaction were acceptable following total knee arthroplasty in Asian patients with severe knee stiffness.

The Role of Prefracture Health Status in Physical and Mental Function After Hip Fracture Surgery.

OBJECTIVES: To examine the associations of 3 measures of prefracture health status (physical function, mental function, and comorbidity count) with trajectories of physical and mental function at 1.5, 3, 6, and 12 months after hip fracture surgery. DESIGN: Single-center observational study. SETTING: Singapore General Hospital (an acute hospital). PARTICIPANTS: Patients aged ≥60 years who underwent first hip fracture surgery between June 2011 and July 2016 (N = 928). INTERVENTION: None. MEASUREMENTS: We used data collected prospectively from the hospital's hip fracture registry. We used the Short Form-36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) as indicators of physical and mental function, respectively, collected at admission and at 1.5, 3, 6, and 12 months after hip fracture surgery. Comorbidity count at admission was the sum from a list of 10 common diseases associated with poorer physical function. RESULTS: Prefracture physical function and prefracture mental function demonstrated time-varying associations (interaction P < .001 and P = .001, respectively) with postfracture physical function; the associations were small initially but increased in strength up to 6 months and stabilized thereafter. In contrast, the strength of the association between comorbidity count and postfracture physical function were time-invariant (-0.52, P = .027). The strength of the associations between all 3 measures of prefracture health status and postfracture mental function were also constant over time (0.09, P = .004, for physical function; 0.38, P < .001, for mental function; -0.70, P = .034, for comorbidity count). CONCLUSIONS/IMPLICATIONS: The time-varying associations between prefracture health status and postfracture physical function suggest that even for patients with good prefracture health status, initial recovery may be slow. Our findings can be useful to clinicians and therapists in their prognostic evaluations and in management of patients' expectation for recovery.

Surgical site infection after primary total knee arthroplasty is associated with a longer duration of surgery.

PURPOSE: Surgical site infection (SSI) is a serious complication following total knee arthroplasty (TKA) leading to considerable morbidity. The incidence is reported to be up to 2%. Risk factors continue to be an area of intense debate. Our study aims to report the incidence of SSI and identify possible risk factors in our patients undergoing TKA. METHODS: Prospectively collected data for 905 patients who underwent elective unilateral TKA by a single surgeon from February 2004 to July 2014 were reviewed. Patient demographics and relevant co-morbidities such as diabetes and heart disease were analysed. The presence of superficial wound infections and/or prosthetic joint infections was included. RESULTS: The overall infection rate was 1.10% (10 of 905 patients). Six patients (0.66%) were diagnosed with superficial infections and four with PJI (0.44%). The mean operative duration for TKA with SSI was significantly longer at 90.5 ± 28.2 min, compared to 72.2 ± 20.3 min in TKA without SSI ( p = 0.03). All superficial infections occurred within the first month post-surgery and were self-limiting with oral antibiotics. The four patients with PJI required repeated procedures following TKA, including debridement, implant removal and/or revision arthroplasty. None of the 10 patients had a history of diabetes. There were no significant differences in demographics and co-morbidities between those who developed infection after TKA and those who did not. CONCLUSION: An overwhelming majority had good outcomes with only four deep infections resulting in revision surgery. We report that the risk of infection in TKA was significantly associated with a longer operative duration.

The Impact of Diabetes on Patient Outcomes After Total Knee Arthroplasty in an Asian Population.

BACKGROUND: Diabetes is implicated with poorer outcomes and more complications after total knee arthroplasty (TKA). We aim to determine whether diabetes affects infection risk, functional outcomes, patient-reported outcome measures, and patient satisfaction in Asian patients after TKA. METHODS: Prospectively collected data for 905 patients who underwent unilateral TKA by a single surgeon from February 2004 to July 2014 were reviewed, of which 123 (13.6%) patients suffered from diabetes. At 2-year follow-up, the change in range of motion of the operated knee, body mass index, Knee Society Score, Oxford Knee Score (OKS), and Short Form-36 from baseline was compared between diabetic and nondiabetic patients. We also analyzed the length of hospitalization stay, infection risk, and patient satisfaction between the 2 groups. RESULTS: Compared with nondiabetic patients, diabetic patients had significantly poorer preoperative OKS (37.6 on 8.3 to 35.8 .38.0, P = .02) and Short Form-36 Mental Component Score (48.3 Me11.2 to 51.7 1.10.7, P = .01). At 2-year follow-up, diabetes continued to be associated with poorer OKS of 21.2 018.4 and Knee Society Score Function score of 64.7 Fu20.9 compared to 19.1 0.6.2 (P = .02) and 71.8 0220.1 (P = .01) respectively in nondiabetic patients. Interestingly, the difference in mental well-being was no longer significant after TKA. A significantly larger proportion of diabetic patients (50%) had a reduction in body mass index after TKA compared to 36% in nondiabetic patients (P < .01). There was no difference in range of motion, length of hospitalization stay, infection risk, and patient satisfaction. CONCLUSION: Despite poorer physical scores throughout, diabetic patients are no less satisfied and had significantly greater improvement in mental well-being and weight reduction after surgery.

Comparative performance of isometric and isotonic quadriceps strength testing in total knee arthroplasty.

BACKGROUND: Early quadriceps muscle strength assessment after a total knee arthroplasty (TKA) provides timely information on progress, but little is known about the pain profile and predictive validity associated with common clinical muscle strength tests. This study aimed to, in patients with a recent TKA, examine the associations of isometric and isotonic quadriceps strength with gait speed, accounting for knee pain experienced during testing. METHODS: A sample of 76 patients (mean age 68 years; 46 women) with a recent TKA (median, 1.5 months) participated. Quadriceps strength was measured on both limbs using a knee extension machine. Isotonic strength was assessed with a one-repetition maximum test. Isometric strength was measured at 40° and 70° of knee flexion using a custom-built load cell. To allow for valid comparisons between the tests, quadriceps strength symmetry ratios were calculated. Knee pain during testing was measured using an 11-point pain scale. Fast gait speed was measured using the 10-m walk test. RESULTS: Compared with isotonic test, quadriceps strength ratio was higher for the 40° flexion isometric test (P = 0.01), and this difference may be explained by the lower knee pain intensity elicited during the isometric tests (P's < 0.001). All strength measures were closely associated with fast gait speed after adjustment for knee pain and covariates (P's < 0.001). CONCLUSIONS: Early in the post-TKA period, isometric and isotonic strength tests may be used to assess quadriceps strength but these tests are not interchangeable. Isometric quadriceps testing may be preferable to isotonic testing as it was associated with lower knee pain intensity.

Comparative study on clinical results of arthroscopic repair of anteroinferior, superior, and combined glenoid labral tear.

BACKGROUND: The purpose of this prospective study is to compare and correlate the clinical results of arthroscopic repair of a combined anteroinferior and superior labral lesion with those of an isolated anteroinferior labral lesion or type II superior labral tear from anterior to posterior (SLAP) lesion. METHODS: A comparative study involving patients who underwent arthroscopic labral repairs in a tertiary hospital between 2010 and 2014 was conducted. A total of 96 patients were divided into three groups: Group A consisted of 61 patients with the anteroinferior labral lesion, group B consisted of 16 patients with the type II SLAP lesion, and group C consisted of 19 patients with the combined anteroinferior and superior labral lesion. Patient demographics, preoperative and postoperative pain scores, shoulder functional scores (Constant Shoulder Score, UCLA (University of California at Los Angeles) Shoulder Score, and Oxford Instability Score), and shoulder ranges of motion were measured and compared. RESULTS: Except that patients from group B were generally older (28.8 vs. 22.2 for group A and 22.0 for group C, p = 0.04) at the time of surgery, no significant differences exist among the three groups in patient demographics and relevant clinical data. Preoperative and 2-year postoperative clinical outcomes, as well as the improvements, were comparable among the three groups. Low failure rates were observed for all three groups (6% vs. 10% vs. 11%, p = 0.999). CONCLUSIONS: Patients with the type II SLAP lesion underwent surgery at an older age. With appropriate surgical procedures, equivalent postoperative results can be expected for combined anteroinferior and superior labral lesion repair compared to isolated labral lesion repair.

Clinical and radiological outcomes of concomitant endoscopic gastrocnemius release with scarf osteotomy.

BACKGROUND: Studies showed patients with hallux valgus also have tight gastrocnemius concomitantly. This study aims to investigate (1) prevalence of tight gastrocnemius in symptomatic hallux valgus (2) clinical and radiological outcomes of concomitant endoscopic gastrocnemius release with scarf osteotomy. METHODS: Between January 2011 to December 2013, 224 patients underwent hallux valgus surgery were evaluated. They were categorized into 2 groups: scarf osteotomy (n=195), scarf and endoscopic gastrocnemius release (combine, n=29). Clinical outcome measures assessed included VAS, AOFAS Hallux MTP-IP and SF-36 scores. Radiological outcomes included HVA, IMA, HVI and TSP. All patients were prospectively followed up for 6 and 24 months. RESULTS: The prevalence of ipsilateral gastrocnemius tightness in symptomatic hallux valgus is 12.9%. No significant difference in preoperative clinical outcomes between the two groups (all p>.05). Although AOFAS was 6±2 points poorer in the combine group compared to the scarf group at 6 months follow up (p=0.021), at 24 months, all clinical outcomes were comparable between the two groups (all p>0.05). Significant difference in the HVA change between the groups were observed but comparable radiological outcomes in IMA, TSP and HVI at 24 months follow up. CONCLUSIONS: We conclude clinical and radiological outcomes of concomitant endoscopic gastrocnemius release and scarf osteotomy are comparable with scarf osteotomy alone at 24 months.

No Difference in Functional Outcomes after Total Knee Arthroplasty with or without Pinless Navigation.

This study aims to investigate the functional outcomes of pinless navigation (BrainLAB VectorVision Knee 2.5 navigation system; Munich, Germany) as an intraoperative alignment guide in total knee arthroplasty (TKA). A prospective, 24-month follow-up study of 100 patients who were scheduled and randomized into two groups, the pinless navigation and conventional surgery, was conducted. All TKAs were performed with the surgical aim of achieving neutral coronal alignment with the 180-degree mechanical axis. The outcomes measured in this study were Oxford Knee Score (OKS), Knee Society Score (KSS), Short Form-36 (SF-36), and range of motion (ROM). At 24-month postoperatively, four and two patients were lost to follow-up from the pinless navigation group and conventional group, respectively. There were no significant differences in absolute scores of the OKS, KSS, and ROM, as well as changes from preoperative baseline, between pinless navigation and conventional groups at both 6 and 24 months postoperatively. Pinless navigation results in comparable functional outcomes as conventional TKA at 6 and 24 months postoperatively.