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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. 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. 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

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.

We report our experience with the Minimally Invasive Chevron Akin (MICA) technique for correcting hallux valgus, and evaluate its effectiveness and associated complications.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)).Mean HVA and IMA decreased from 30.4° and 13.9°-10.9° and 10.2° respectively (p0.05). The mean AOFAS score improved from an average of 59.0-93.7 (p0.05). All patients reported a VAS score of 0 post-operatively, and the 4 SF-36 domains improved significantly (p0.05).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.

ObjectivesPain sensitization could be a risk factor for poor outcomes after knee replacement surgery (KR) for knee osteoarthritis (KOA). We aimed to evaluate the association between pre-operative central and peripheral pain sensitization measured using a digital pressure algometer and KR outcomes.MethodsConsecutive patients with severe KOA listed for KR were recruited. Sociodemographic and symptoms data were collected prior to surgery. Pre-operative pressure pain thresholds (PPTs) were measured using a digital pressure algometer at the index knee and forearm. Patient satisfaction at 6 and 12 months after KR was assessed using a 4-point Likert scale, and dichotomized to satisfied and dissatisfied to KR. Western Ontario and McMaster Universities Index (WOMAC) Pain and function was assessed. The associations between pre-operative PPTs with KR outcomes at 6 and 12 months were evaluated.ResultsOf the 243 patients recruited, response rate at 6 and 12 months were 95.5% and 96.7%. The dissatisfaction rates were 8.2% and 5.1% at 6 and 12 months. There was no statistically significant association between pre-operative index knee or forearm PPTs and patient satisfaction. PPTs measured at the knee, but not the forearm, were weakly associated with change in the WOMAC pain score at 12 months, after adjustment for confounding factors.ConclusionPre-operative central sensitization, measured by handheld digital algometry, was not statistically significantly associated with satisfaction or change in pain after KR. Pre-operative peripheral sensitization was associated with change in pain symptoms after KR; however, this association was weak and unlikely to be a meaningful predictor of KR outcome in clinical practice.

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. 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. 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%). 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. III.

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.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.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.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.

Background Although isokinetic dynamometry often serves as a reference to assess the concurrent validity of weight-machine isotonic strength testing, it is unknown whether isokinetic knee strength is associated with knee function and activity level more strongly than isotonic knee strength in patients with an anterior cruciate ligament reconstruction (ACLR). This study aimed to compare the associations of isokinetic and isotonic knee strength with knee function and work-and-sports activity levels in patients with ACLR. Methods One-hundred and six patients with a unilateral ACLR participated. At three months post-ACLR, isokinetic quadriceps and hamstrings strength was measured using an isokinetic dynamometer whilst isotonic strength was measured using weight machines. At six months post-ACLR, patients performed the single-leg hop-for-distance test. Self reported knee function and work-and-sports activity levels were assessed by the Lysholm Knee Score and Tegner Activity Score, respectively. Results In multivariable analyses, isotonic and isokinetic quadriceps strength limb symmetry indices (LSIs) were significantly associated with all outcomes ( P ≤ 0.03) and had comparable predictive performance. Isotonic and isokinetic hamstrings strength LSIs were significantly associated with Lysholm scores ( P ≤ 0.03) and isotonic hamstrings strength was additionally significantly associated with hop-for-distance LSI ( P = 0.01). Conclusions Weight machine-derived isotonic quadriceps strength was independently and consistently associated with knee function and work-and-sport activity level post-ACLR. Isokinetic knee strength was not more strongly associated than isotonic knee strength with the various outcomes. These findings have logistic and economic implications because the isokinetic dynamometer system is relatively expensive and its operation requires more logistic effort and technical skills.

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.

Background Studies regarding postoperative outcomes after primary total hip arthroplasty (THA) in patients who have comorbid factors tend to focus on medical diseases. However, there is a paucity of literature examining the effect of a patient's orthopedic surgical history on outcomes after THA. Significantly, there are currently no studies on the effect of spinal fusion surgery on THA outcomes. Methods A review of 82 consecutive patients who had prior spinal fusion surgery who underwent elective THA from January 1, 2006 to December 31, 2015, was conducted. A matching cohort of 82 patients was selected from the remaining THA patients to maintain a 1:1 ratio control group. This cohort of 82 patients was matched for age, gender, body mass index ±5, preoperative Oxford score ±10, total Short Form-36 score ±10, and total Western Ontario and McMaster Universities Arthritis Index (WOMAC) score ±50. Data on the same functional outcomes were prospectively collected at 6-month and 2-year follow-up for comparison. Results Patients without spinal fusion had better outcome scores than patients with prior spinal fusion, specifically in their 6-month WOMAC scores (253.33-225.07; P = .046), their 2-year Short Form-36 total scores (79.71-69.21; P = .041), and their 2-year WOMAC scores (213.5-267.41; P = .054). Conclusion This study demonstrates that patients with prior spinal fusion had worse outcomes after THA than patients without prior spinal fusion. This has clinical significance in counseling patients with previous spinal fusion undergoing THA.

Summary Background Rehabilitation is widely advocated and provided as a standard of care for patients with total knee arthroplasty (TKA) but its effects on intermediate- to longer-term physical function is unclear. Also unknown is the relationship between the number of rehabilitation sessions attended and functional outcomes. Methods We conducted a prospective cohort study of 1540 patients who had undergone TKA and were referred for rehabilitation. Physical function was indexed by the Short-Form 36 (SF-36) physical function score at 6 months post-TKA. We used multivariable linear regression to assess the association between rehabilitation attendance and Month-6 physical function. Among patients who attended rehabilitation, multivariable linear regression was used to examine the dose–response association between the number of sessions attended and Month-6 physical function. Results Of the 1540 patients, 68 patients did not attend rehabilitation, 86 patients attended one session, and 1386 patients attended two or more sessions. Adjusted for the propensity to attend rehabilitation, rehabilitation attendance was independently associated with better Month-6 SF-36 physical function (point estimate, 5.0 points; 95% CI, 0.5–9.5; P = 0.028 compared with patients with no rehabilitation). Among patients who attended rehabilitation, attending five sessions was associated with a 3.6-point increase in SF-36 scores (95% CI, 0.8–6.5; P = 0.01) relative to patients who attended one session. Conclusions Rehabilitation attendance post-TKA is associated with an increase in self-report physical function. Among patients who attended rehabilitation, a modest dose–response relationship was observed between the number of sessions and functional outcomes.

Summary Background The role of laminar flow (LAF) is contradictory with several studies failing to replicate risk reduction. The 2016 World Health Organization guidelines identified this lack of good comparative studies. Aim To analyse the use of LAF and the incidence of prosthetic joint infections (PJIs) in Asian patients undergoing total knee replacement (TKR). Methods Patients who underwent standard cemented posterior-stabilized TKR from 2004 to 2014 were reviewed from a prospectively collected single-surgeon database. Revision, traumatic and/or inflammatory cases were excluded. The type of airflow used was identified. The technique and surgical protocol for all procedures were similar. Tourniquets and inserted drains were routinely used. Patellar resurfacing was not performed. Patients were followed up at the outpatient clinics at regular intervals up to two years. At each visit, the patient was assessed for the occurrence of PJI. Findings Of the 1028 procedures, 453 (44.1%) were performed in an LAF operating theatre (OT) whereas 575 (55.9%) were performed in a non-LAF OT. There were no significant differences between the two groups in terms of age, gender, or side of procedure. The overall incidence of PJI was 0.6% (N = 6). Three (50%) occurred in an LAF OT whereas three (50%) occurred in a non-LAF OT. This was not statistically significant. Conclusion Laminar flow systems are costly to procure and maintain. With modern aseptic techniques, patient optimization, and use of prophylactic antibiotics, laminar flow does not appear to further reduce risk of PJI in Asian patients after TKR.

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.

Purpose To identify predictors for rehabilitation outcome in Asian geriatric hip fracture patients. Methods Records of 153 consecutive Asian patients aged 61 to 99 years who underwent surgery for hip fracture and were followed up for at least one year were reviewed. They were stratified into 4 age-groups: 60–69 years (n=27), 70–79 years (n=70), 80–89 years (n=50), and ≥90 years (n=6). Any comorbidity, regardless of severity, was recorded. Pre-injury and postoperative functional status was evaluated using the 36-item Short Form Health Survey. Relative functional gain (RFG) is equal to absolute functional gain (physical component summary [PCS] score at one year minus PCS score at 6 weeks) divided by the maximum potential gain (maximum PCS score minus PCS score at 6 weeks). RFG of Results In univariate analysis, age 80–89 years (p=0.026), arthritis (p=0.082), and hypercholesterolaemia (p=0.014) were predictors for RFG. In multivariate analysis, age 80–89 years (p=0.016) remained a predictor for poor RFG, and hypercholesterolaemia remained a predictor for good RFG. Conclusion Poor rehabilitation outcome was associated with patient age of 80–89 years; an orthogeriatric approach may be beneficial in optimising rehabilitation outcome in elderly hip fracture patients.

The Knee Society Clinical Rating System (KS) is one of the most popular tools used to assess patient outcome after total knee arthroplasty (TKA), but its minimal clinically important difference (MCID) has not been identified. This study aims to identify the MCID of KS function score (KS-FS) and knee score (KS-KS) after TKA in patients with primary knee osteoarthritis.The authors retrospectively analysed patients who underwent TKA for primary knee osteoarthritis between 2005 and 2015 in a single institution. KS-FS, KS-KS, and Oxford Knee Score (OKS) were collected pre-operatively and 2 years post-operatively. Patient satisfaction with TKA at 2 years was also collected. Anchor-based approach with 2 external indicators was used. The MCID for KS-FS and KS-KS was determined using simple linear regression according to patient satisfaction with TKA and the MCID of OKS.The mean age of the 550 subjects studied was 66 ± 8 years. There were 373 (67.8 %) female subjects. The KS-FS improved by 22.8 (95 % CI 20.9-24.6) points, and the KS-KS improved by 44.4 (95 % CI 42.6-46.3) points. The MCID identified for KS-FS is between 6.1 (95 % CI 5.1-7.1) and 6.4 (95 % CI 4.4-8.4) and between 5.3 (95 % CI 4.3-6.3) and 5.9 (95 % CI 3.9-7.8) for KS-KS.This is the first study, to the knowledge of the authors, to identify the MCID of KS. This will allow future trials to have an accurate prediction of sample size. Clinically, physicians will be able to better interpret outcomes of TKA studies to guide a treatment option.IV.

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.

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.

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

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.

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.

Primary constrained condylar knee arthroplasty does not affect clinical and functional outcomes at 2 years when 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.

Introduction: Patients suffering from bilateral knee osteoarthritis often require bilateral total knee arthroplasty (TKA) to alleviate symptoms. There is controversy surrounding the approach to the surgical treatment of such patients. We asked if Asian patients undergoing staged-bilateral TKA had any difference in their short-term functional outcomes, comparing the first TKA to the second one and if the interval between the 2 surgeries had any impact of functional outcomes. Materials and Methods: We identified 100 patients from a single surgeon from 2006 to 2010 who had staged-bilateral TKA and had at least 2 years of follow-up for each TKA. The time interval between the first and second TKA ranged from 6 months to 1 year. Range of motion, Oxford knee questionnaire scores, knee scores and function scores at 6 months and 2 years of follow-up were then compared between the first and second TKA using the Student’s T-test. Results: Although length of stay was reduced and time to ambulation was shorter for the second TKA, there were no significant differences in functional outcomes at 2 years. There was also no difference in outcome when patients were stratified according to time interval between TKAs. Conclusion: Staged-bilateral TKA continues to be a good option for patients presenting with severe bilateral knee osteoarthritis. The second arthroplasty has similar functional outcomes as the first arthroplasty. Our results can be used in preoperative counselling of patients undergoing staged-bilateral TKA. Key words: Counselling, Orthopaedic surgery, Osteoarthritis

A 24-month prospective follow-up study was carried out to compare perioperative clinical outcomes, radiographic limb alignment, component positioning, as well as functional outcomes following total knee arthroplasty (TKA) between patient-specific instrumentation (PSI) and conventional instrumentation (CI). Ninety consecutive patients, satisfying the inclusion and exclusion criteria, were scheduled to undergo TKA with either PSI or CI. A CT-based PSI was used in this study, and a senior surgeon performed all surgeries. Patients were clinically and functionally assessed preoperatively, 6 and 24 months post-operatively. Perioperative outcomes were also analysed, including operating time, haemoglobin loss, the need for blood transfusion, length of hospitalisation, and radiographic features. At 24-month follow-up, clinical and functional outcomes were comparable between the two groups. PSI performed no better than CI in restoring lower limb mechanical alignment or improving component positioning. There were no differences in operating time, haemoglobin loss, transfusion rate, or length of hospitalisation between PSI and CI. No significant clinical benefit could be demonstrated in using PSI over CI after 24 months, and routine use of PSI is not recommended in non-complicated TKA. II.

Objective Quadriceps strength deficits and gait speed limitations remain significant issues after total knee arthroplasty (TKA), yet detailed longitudinal data characterizing these measures and their predictors are limited. This study aimed to describe the time course of knee range of motion, quadriceps strength, and gait speed post-TKA, and to assess whether sex and body mass index (BMI) influenced the time recovery of these measures. Methods A total of 1,025 patients (mean ± SD age 67 ± 8 years) undergoing primary TKA participated. At 4-, 8-, 12-, and 16-weeks postsurgery, knee range of motion, quadriceps strength, and gait speed were quantified. The associations of the knee and gait measures profile over time with sex and BMI were assessed using generalized least squares modeling. Results The various knee and gait measures improved nonlinearly over time, with substantial improvements observed in the first 8–10 weeks postsurgery. Sex and BMI influenced the time course of quadriceps strength (P < 0.001 for all interactions): improvements in quadriceps strength over time were slower in women and in patients with higher BMI. Post-TKA gait speed was consistently lower in women than in men, while BMI was negatively and nonlinearly related to gait speed. Conclusion Although the various knee and gait measures improved over time, women and patients with higher BMI had poorer functional outcomes. The present study highlights the need for a mechanistic understanding of the results and targeted management of these patient subgroups.

Background:Metatarsus adductus (MA) increases the risk of developing symptomatic hallux valgus (HV). This study aimed to determine the prevalence of MA in patients with symptomatic HV and to evaluate how it affected the functional outcome after scarf osteotomy.Methods:Between January 2007 and June 2012, a total of 206 patients who underwent scarf osteotomy for symptomatic HV at a tertiary hospital were included. The metatarsus adductus angle (MAA) was determined using the Modified Sgarlato method, and these patients were categorized into 2 groups: MA (MAA > 20 degrees); and Control (MAA ≤ 20 degrees). The patients were prospectively followed for 2 years.Results:The prevalence of MA was 33% (68/206) with a mean MAA of 24 ± 4 degrees (range = 20-39). There was a 21 ± 12 degrees and 18 ± 9 degrees improvement in hallux valgus angle for the MA and Control groups, respectively ( P = .061), whereas there was a 6 ± 4 degrees and 6 ± 3 degrees improvement in intermetartarsal angle for the MA and Control groups, respectively ( P = .475). The visual analog scale, AOFAS Hallux Metatarsophalangeal-Interphalangeal Scale, and Physical and Mental Component Scores were comparable between the 2 groups both preoperatively and at 2 years’ follow-up (all P > .05). Two patients in the control group required revision surgery for recurrence symptomatic HV.Conclusion:The authors conclude that MA did not predispose the patient to poorer functional outcome after scarf osteotomy with the advent of good operative techniques.Level of Evidence:Level II, prospective comparative study.

Background: Obesity is a global epidemic, but its effect on foot and ankle surgeries is not well defined. This study aimed to investigate the influence of obesity on functional outcome scores, incidence of postoperative surgical site infection (SSI), and repeat surgery after hallux valgus (HV) corrective surgery. Methods: Between January 2007 and December 2011, 452 patients who underwent HV corrective surgery at a tertiary hospital were evaluated. They were categorized into 2 groups based on their body mass index (BMI): (1) BMI less than 30 kg/m2 (control); (2) BMI 30 kg/m2 or more (obese). The patients were prospectively followed for 2 years. Results: Patients in the obese group were significantly older by 4 years (95% CI, 1-7 years) ( P = .043). The preoperative American Orthopaedic Foot & Ankle Society Hallux Metatarsophalangeal-Interphalangeal (AOFAS Hallux MTP-IP) Scale and Physical Component Score were 6 points (95% CI, 1-11 points) and 3 points (95% CI, 1-6 points) poorer, respectively, in the obese group ( P = .014 and P = .032, respectively). However, the Visual Analog Scale, AOFAS Hallux MTP-IP Scale, Physical Component Score, and Mental Component Score were comparable between the 2 groups at 6 months and 2 years of follow-up (all P > .05). Eleven patients (3%) in the control group and 1 patient in the obese group (2%) developed postoperative SSI ( P = .777). Nine patients (2%) in the control group and 7 patients in the obese group (14%) required repeat surgery for complications ( P < .001). Conclusion: The authors conclude that while it is important to warn obese patients of the significantly higher risk of repeat surgery, these patients should not be excluded from undergoing HV surgery. Level of Evidence: Level III, retrospective comparative series.

Anesthetic technique affects perioperative outcomes, but less was known in simultaneous bilateral total knee arthroplasty (BTKA). A single center, retrospective analysis was carried out to prove the hypothesis that utilization of regional anesthesia would result in favorable perioperative outcomes. Medical records of patients admitted for simultaneous BTKA between 2004 and 2013 were analyzed. Two groups, the general anesthesia (GA) and regional anesthesia (RA) group, were identified. Patient preoperative characteristics were compared. Perioperative outcomes measured included blood loss, transfusion requirement, length of hospitalization, operating time, and 30-day perioperative complications. A total of 513 patients were identified, 54.6 % were performed under GA, and 45.4 % under RA. Patient characteristics were similar between the two groups, except that patients operated under GA were younger than those under RA. RA was associated with significantly less perioperative blood loss (981 vs. 1075 mL, p = 0.017) and 30-day complications (6.4 vs. 13.2 %, p = 0.016). Systemic and organ specific infections were particularly lower in the RA group (0.4 vs. 3.9 %, p = 0.009). Transfusion requirement, length of hospitalization, and operating time were similar between the two groups. After correcting for covariates, RA offered a 92 mL (p = 0.023) reduction in blood loss and 49 % less overall complications (p = 0.047), compared to GA. Patients who underwent simultaneous BTKA under RA had lesser blood loss and lower complication rate than GA. The impact of RA can be further exploited to improve perioperative outcomes of simultaneous BTKA in addition to various other interventions.

Introduction: Up to 20% of patients who underwent total knee arthroplasty (TKA) reported dissatisfaction with surgical outcome. Despite the multiple studies looking into the factors contributing to patients' dissatisfaction, little research has been done to examine the subjective reasons and complaints patients have post-arthroplasty. This study aimed to look at an Asian patient population which underwent TKA and examine the factors contributing to patient dissatisfaction and the reasons they were dissatisfied with their surgery. Materials and Methods: A total of 3069 TKAs were performed between January 2011 to April 2013 in a single institution. Preoperative and postoperative variables were prospectively captured, such as standardised knee scores, knee range of motion and patient satisfaction scores. These variables were then analysed with a multiple logistic regression model to determine the statistically significant factors that contribute to patients' satisfaction. Dissatisfied patients were individually interviewed to find the reasons for their unhappiness. Preoperative variables were then analysed to identify the statistically significant factors associated with these subjective complaints. Results: Minimum duration of follow-up was 2 years, with an overall patient satisfaction rate of 91.3%. Preoperative variables contributing to patient dissatisfaction included female gender and better knee flexion. Postoperative variables included lesser improvement in knee flexion at 6 months postoperatively, as well as poorer scores in various validated knee scores at both 6 months and 2 years postoperatively. The top reason for dissatisfaction was pain. Weakness, another reason for patient dissatisfaction, had statistically significant preoperative predictors of increased age and poorer Short-Form 36 Physical Component Score. Conclusion: Although TKA has an impressive patient satisfaction rate in this Asian population, factors contributing to postoperative dissatisfaction suggest a targeted group of patients would benefit from preoperative counselling. The top reason for postoperative dissatisfaction in the study was pain. Key words: Outcomes, Quality of life, Satisfaction

Background: Current literature reporting on the impact of BMI on outcomes of orthopaedic surgical procedures is varied and inconsistent. The purpose of our study was to evaluate if body mass index (BMI) affects outcomes of primary anterior cruciate ligament reconstruction (ACLR) in an Asian population. Methods: We retrospectively reviewed prospectively collected data of 141 consecutive patients who underwent primary ACLR by a single surgeon, the senior author of this study. Flexion range, International Knee Documentation Committee (IKDC) score, KT-1000 translation, Tegner activity level scale, Lysholm score and satisfaction were assessed preoperatively and at 2 years postoperatively. The patients were then stratified into two groups: normal-BMI and high-BMI in accordance with WHO classification. Outcomes were then compared between the two groups. All statistical analysis were performed on IBM SPSS Statistics 20. Results: There were 81 patients in the normal-BMI group (BMI 18.5 to 24.9) and 60 patients in the high-BMI group (BMI ≥25). Preoperatively, the only differences were in the gender proportions as well as the pre-injury Tegner score. 2-years postoperatively, patients in the normal-BMI group had better flexion (139° versus 130°; P=0.0001), Tegner scores (5.7 versus 4.8; P=0.005) and satisfaction rate (99% versus 90%; P=0.041). There were no differences in graft failure or complication rates. Conclusions: Obese patients had poorer range of motion and Tegner scores as compared to their nonobese counterparts following primary ACLR.

Background:Recent studies have shown a correlation between scapular geometry and the development of atraumatic rotator cuff tears. However, a paucity of literature is available on the effects of critical shoulder angle (CSA) and acromial index (AI) on functional outcomes after arthroscopic rotator cuff repair.Hypothesis/Purpose:The purpose was to investigate the influence of CSA and AI on 24-month functional outcomes after arthroscopic rotator cuff repair. The hypothesis was that a larger CSA or AI would result in poorer postoperative outcomes.Study Design:Cohort study; Level of evidence, 3.Methods:The study included 147 patients who underwent arthroscopic double-row rotator cuff repair for radiologically documented full-thickness supraspinatus tears. An independent reviewer measured the CSA and AI on preoperative radiographs. These patients were prospectively enrolled and were evaluated preoperatively as well as at 3, 6, 12, and 24 months postoperatively. Functional outcome was assessed with the Constant Shoulder Score (CSS), Oxford Shoulder Score (OSS), and University of California at Los Angeles (UCLA) Shoulder Rating Scale. The patients were first divided based on CSA: (1) ≤35° (control CSA) and (2) >35° (increased CSA); and then based on AI: (1) ≤0.7 and (2) >0.7. The Student unpaired t test, Pearson chi-square test, and Pearson correlation were performed to examine the influence of CSA and AI on postoperative functional outcome scores.Results:At 6 months of follow-up, the CSS, OSS, and UCLA Shoulder Rating Scale were 10 ± 1, 4 ± 2, and 3 ± 1 points poorer in the increased CSA group compared with the control CSA group ( P = .005, P = .030, and P = .035, respectively). These scores were not significantly different between both AI groups. By 24 months of follow-up, all outcome scores were comparable between both CSA groups as well as between both AI groups. No significant correlation was found between either CSA or AI when compared with CSS, OSS, or UCLA Shoulder Rating Scale at 24 months of follow-up.Conclusion:CSA and AI do not appear to influence 24-month functional outcomes postoperatively and hence are not contraindications to arthroscopic rotator cuff repair.

Background older adults with total knee arthroplasty (TKA) frequently undergo rehabilitation to address limited knee flexion range-of-motion, quadriceps weakness and gait speed limitations. This study aimed to develop age- and sex-specific recovery curves of knee flexion range-of-motion, quadriceps strength and fast gait speed post-TKA. Methods a population-based sample of 2,987 patients undergoing primary TKA participated, of whom 2015 (68%) were 65 years of age or older. At 4, 8 and 12 weeks post surgery, knee flexion range-of-motion, quadriceps strength and fast gait speed were quantified. Quantile regression was used to determine the percentiles of the knee and gait measures. Results the various knee and gait measures improved nonlinearly over time, with substantial improvements observed in the 1st 8-10 weeks post surgery. Age-specific, sex-specific recovery curves were developed to show the recovery patterns at multiple percentile levels. A web interface was created to facilitate easy computation of the percentile rank for a given outcome value. Conclusions we have provided reference percentile values for knee flexion range-of-motion, quadriceps strength and gait speed recovery post-TKA. Such information may assist rehabilitation professionals in interpreting outcomes and quantifying deviations from the expected recovery pattern.

The objective of this study is to evaluate the prevalence of patients who lost or gained weight following unicompartmental knee arthroplasty (UKA), the effect of post-operative body mass index (BMI) changes on functional outcomes and quality of life (QoL), and predictive factors associated with BMI changes. Prospectively collected data of 1043 patients who underwent UKA between 2000 and 2014 were reviewed. BMI, Knee Society Knee Score and Function Score, Oxford Knee Score (OKS), Short-Form 36 (SF-36) Physical Component Score (PCS) and Mental Component Score and proportion of patients attaining OKS/SF-36 minimal clinically important differences (MCID) were recorded preoperatively and at 2 years post-operatively. The patients were stratified into three groups based on weight changes for further analysis. Following UKA, 138 (13.3%) patients had lost weight, 695 (66.6%) maintained their weight, and 210 (20.1%) gained weight. Patients in all groups demonstrated significant improvements in functional and SF-36 PCS scores at 2 years post-operatively. There were no significant differences in functional outcomes, QoL or revision rate between the groups. Post-operative BMI changes were not correlated with any outcome scores or attainment of MCID (n.s.). This is the first study that evaluates change in BMI following UKA. It demonstrated a higher proportion of patients who gained weight as compared to those who lost weight. Post-operative BMI changes did not appear to affect outcomes of UKA. These findings will provide important information to surgeons when counselling patients regarding BMI change and its effect on outcomes after UKA. Level III.

Study Design Prospective cohort study. Background Optimal management of patients with low back pain (LBP) relies on accurate prognosis of future clinical outcomes. The STarT Back Screening Tool (SBT), a prognostic index developed and validated in the primary care setting, has 3 scoring measures: SBT overall, psychosocial, and categorical scores. Objective Our study aimed to compare the predictive validity of 3 SBT measures with future pain intensity in patients receiving physical therapy for LBP. Methods Two hundred seven patients with LBP receiving physical therapy completed the SBT at initial (baseline) evaluation and were evaluated 12 weeks later for their pain intensity. Multivariable proportional odds regression was used to evaluate the associations of the various SBT measures with pain intensity at follow-up. Results Adjusting for covariates, all SBT measures were positively and significantly associated with the odds of greater pain intensity at follow-up evaluation (P

A precept of a successful total knee arthroplasty (TKA) would be a well balanced, stable knee. We analyzed the effects of medial-lateral (ML) stability on functional outcome at 2years post-operatively. Prospectively collected Joint Registry data of all unilateral primary TKAs between 2004 and March 2008 were used. ML stability (Group 1

This study aimed to investigate the clinical outcome of total knee arthroplasty (TKA) after previous high tibial osteotomy (HTO) using cruciate retaining (CR) versus posterior stabilized (PS) prostheses. Between 2001 and 2010, 133 patients who underwent TKA after previous HTO were included in this study and prospectively followed up for two years. Two independent assessors recorded the range of motion of the operated knee, anterior–posterior (AP) laxity, medial–lateral (ML) laxity, Oxford Knee Score (OKS), Knee Society Function Score (KSFS) and Knee Society Knee Score (KSKS). Thirty-three patients received CR prostheses, while 100 patients received PS prostheses. The median (inter-quartile range) knee flexion at 6 months and 2 years post-TKA was 101° (90, 116) and 110° (90, 118), respectively for the CR group, compared to 115° (100, 121) and 118° (108, 125) for the PS group (p = 0.010 and p = 0.009, respectively). AP and ML laxities were comparable in both groups of patients. While both groups of patients showed improvement in OKS, KSFS and KSKS at 6 months and 2 years post-TKA, there was no significant difference in these clinical scores between the two groups at both time points of follow-up. None of the 133 patients required revision surgery. Although PS prostheses offer better knee flexion in TKA after previous HTO, the knee stability, clinical scores and revision rate at 6 months and 2 years post-TKA are comparable between CR and PS prostheses. The authors conclude that CR is an alternative to PS prostheses in patients undergoing TKA after previous HTO. III.

We aim to compare the patient profile and outcomes after TKA between the different racial groups in Singapore. Prospective data were collected from 364 patients who underwent TKA in Singapore General Hospital from January 2006 to May 2010. Patients were stratified according to ethnicity and we compared their preoperative demographic data, Short-Form 36 (SF-36), Oxford Knee (OKS) as well as Knee Society Scores (KSS). Malays were younger (62.0 ± 5.3) at time of surgery (p=0.05) and the body mass index of Chinese (27.9 ± 4.7) was lower than Malay (30.4 ± 5.0) and Indian (31.5 ± 4.5) patients (P0.005). Malay (40.3 ± 11.0) and Indian (39.2 ± 9.3) patients had less favourable preoperative OKS than Chinese (35.9 ± 7.8) patients (P0.05). All 3 ethnic groups achieved statistically significant improvements in outcome measures but did not differ significantly between the ethnicities.

Objective To evaluate whether preoperative range of motion is a key determinant of postoperative range of motion in Asian patients undergoing conventional total knee arthroplasty. Methods A retrospective review of 302 patients who underwent primary total knee arthroplasty performed by a single surgeon was conducted. Patients who had a fixed flexion deformity of ≥15° were excluded. Postoperative range of motion (ROM) was measured prospectively. Patients were stratified into two groups: preoperative ROM < 110° and preoperative ROM ≥ 110°. Postoperative ROM and mean change in ROM at 6 months and 2 years of follow-up were then compared using Student's t-test. Results Group of ROM < 110° had a poorer postoperative range of motion at both 6-months and 2-years of follow-up than Group of ROM ≥ 110° (P < 0.001). Postoperatively, Group of ROM < 110° had gained range of motion whereas Group of ROM ≥ 110° had lost range of motion (P < 0.001). Conclusions Similar to the Western population, preoperative range of motion is a key determinant of postoperative range of motion in Asian patients. This should be taken into consideration by surgeons during preoperative planning and in managing patients’ expectations.

Background Restoration of the native joint line in total knee arthroplasty is important in restoring ligamentous balance and normal knee kinematics. Failure to achieve this could lead suboptimal outcomes. The purpose of this study was to analyze the clinical and functional outcome of patients who demonstrated joint line changes after computer-assisted (CAS) total knee arthroplasty (TKA). Methods One hundred sixty-eight patients (168 knees) underwent CAS TKA by two surgeons at a single institution with 2 years follow-up. The final change in joint line was calculated from the verified tibial resection and distal femoral cuts. Group A patients had joint line changes of less than 4 mm and Group B patients had joint line changes of more than 4 mm. Post-operative Oxford scores, Knee scores, Function scores and SF-36 scores were obtained at 6 months and 2 years post TKA. Results There was significant linear correlation between joint line changes and Oxford scores (P = 0.0001), Function scores (P = 0.0001) and Knee scores (P = 0.0001) at 6 months and Oxford scores (P = 0.0001) alone at 2 years with increasing joint line changes having poorer outcome scores. Group A compared to Group B patients demonstrated better Oxford scores (P = 0.0001), Function scores (P = 0.0001), Knee scores (P = 0.0001) and total SF-36 scores (P = 0.003) at 6 months as well as better Oxford scores (P = 0.0001) and Knee scores (P = 0.014) at 2 years. Conclusions CAS is a useful intra-operative tool for assessing the final joint line in TKA. Outliers in joint line changes of ≥ 4 mm are associated with poorer clinical outcome scores. Level of evidence: Prognostic Study, Level II-1.

In Asia, obesity has reached epidemic proportions and physicians are likely to face a burden of obesity-related disorders, of which osteoarthritis of the knee is one. However, it is unclear whether obesity affects improvement of conventional TKAs in Asian patients.We therefore asked whether obese patients with a BMI of 30 kg/m(2) or greater would have worse ROM and function after TKA compared with their nonobese counterparts and whether they would have less improvement preoperatively to postoperatively.We retrospectively reviewed 369 patients who underwent TKAs from 2006 to 2010. We stratified patients into four groups: (1) 98 patients with BMIs less than 25 kg/m(2); (2) 158 patients with BMIs between 25 kg/m(2) and 29.9 kg/m(2); (3) 87 patients with BMIs between 30 kg/m(2) and 34.9 kg/m(2); and (4) 26 patients with BMIs greater than 35 kg/m(2). We then compared ROM, function score, Knee Society score, Oxford Knee Questionnaire, and SF-36 questionnaire(®) across the four groups at 6- and 12-month follow-ups.At the 6-month followup, we found a difference only in the ROM. At the 2-year followup, there were no differences in any functional scores across the four groups. Severely obese patients had greater improvement in postoperative ROM than the other groups but did not have any greater improvement in function.BMI had little clinical impact on short-term outcomes of conventional TKAs in Asian patients. The data suggest that BMI should not be used as a major determinant to exclude obese patients from surgery with the presumption of poorer outcomes.

STUDY DESIGN This is a prospective study. OBJECTIVE A 2-year outcome of erectile dysfunction (ED) in patients younger than 50 years with fracture-unrelated lumbar spine disease requiring surgical decompression for ED is evaluated. Risk factors for ED were also evaluated. SUMMARY OF BACKGROUND DATA There is no literature documenting 2-year follow-up of ED status in young patients with atraumatic lumbar spine disease. METHODS All male patients younger than 50 years who underwent lumbar spine surgery between June 2006 and November 2007 without risk factors for ED were included. Patient demographics, neurological dysfunction, visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index, North American Spine Society score for neurogenic symptoms, and the international index of erectile function-5 scores were recorded preoperatively and at 2 years. Patients who did not complete a 2-year follow-up were excluded. RESULTS.: A total of 75 patients were eligible for the study. Nineteen patients did not complete a 2-year follow-up giving a response rate of 75%. There were 56 patients in the study with a mean age of 38.4 (SD, 7.2; range, 20-49). The most common diagnosis was prolapsed intervertebral disc (77%) for which patients underwent discectomy. Preoperatively, 21 of 56 (37.5%) patients had ED. Despite significant improvement in mean VAS scores for back pain and leg pain, Oswestry Disability Index, and North American Spine Society score for neurogenic symptoms at 2 years (P < 0.01), the mean international index of erectile function-5 scores remained stable. Patients with ED at 2 years had greater back pain (mean VAS score 3.4) compared with patients without back pain (mean VAS score, 1.6; P ≤ 0.01). CONCLUSION Despite excellent outcome in most spine scores postoperatively after lumbar spine surgery, one has to be less optimistic about any improvement in the ED status of patients after surgery. ED is still a problem 2 years after surgery. Back pain reduction may have a significant role in dealing with ED at 2 years postoperatively. LEVEL OF EVIDENCE 2.