Enoxaparin for VTE thromboprophylaxis during inpatient rehabilitation care: assessment of the standard fixed dosing regimen.

BACKGROUND: We aimed to examine the efficiency of fixed daily dose enoxaparin (40 mg) thromboprophylaxis strategy for patients undergoing inpatient rehabilitation. METHODS: This was an observational, prospective, cohort study that included 63 hospitalized patients undergoing rehabilitative treatment following sub-acute ischemic stroke (SAIS) or spinal cord injury (SCI), with an indication for thromboprophylaxis. Anti-Xa level measured three hours post-drug administration (following three consecutive days of enoxaparin treatment or more) was utilised to assess in vivo enoxaparin activity. An anti-Xa level between 0.2-0.5 U/ml was considered evidence of effective antithrombotic activity. RESULTS: We found sub-prophylactic levels of anti-Xa (<0.2 U/ml) in 19% (12/63). Results were within the recommended prophylactic range (0.2-0.5 U/ml) in 73% (46/63) and were supra-prophylactic (>0.5 U/ml) in 7.9% (5/63) of patients. Anti-Xa levels were found to inversely correlate with patients' weight and renal function as defined by creatinine clearance (CrCl) (p<0.05). CONCLUSIONS: Our study confirmed that a one-size-fits-all approach for venous thromboembolism (VTE) prophylaxis may be inadequate for rehabilitation patient populations. The efficacy of fixed-dose enoxaparin prophylaxis is limited and may be influenced by renal function and weight. This study suggests that anti-Xa studies and prophylactic enoxaparin dose adjustments should be considered in certain patients, such as those who are underweight, overweight and or have suboptimal renal function. TRIAL REGISTRATION: No. NCT103593291, registered August 2018.

The effect of center of pressure alteration on the ground reaction force during gait: A statistical model.

BACKGROUND: Foot problems and lower-limb diseases (e.g., foot ulcers, osteoarthritis, etc.), are presented with a ground reaction force (GRF) that may deviate substantially from the normal. Thus, GRF manipulation is a key parameter when treating symptoms of these diseases. In the current study, we examined the impact of footwear-generated center of pressure (COP) manipulations on the GRF components, and the ability to predict this impact using statistical models. METHODS: A foot-worn biomechanical device which allows manual manipulation of the COP location was utilized. Twelve healthy young men underwent gait analysis with the device set to convey seven COP conditions: (1) a neutral condition, (2) lateral and (3) medial offset along the medio-lateral foot axis, (4) anterior and (5) posterior offset along the antero-posterior foot axis, and (6) a dorsi-flexion and (7) plantar-flexion condition. Changes in the magnitude and the early stance-phase impulse of the GRF components across COP conditions were observed. Linear models were used to describe relationships between COP conditions and GRF magnitude and impulse. RESULTS: With respect to ANOVA, the vertical and antero-posterior components of the GRF were significantly influenced by the COP configuration throughout the different stages of the stance-phase, whereas the medio-lateral components were not. The models of vertical, antero-posterior and medio-lateral GRF components were statistically significant. SIGNIFICANCE: The study results are valuable for the development of a method and means for efficient treatment of foot and lower-limb pathologies. The ability to predict and control the GRF components along three orthogonal axes, for a given COP location, provides a strong tool for efficient treatment of foot and lower-limb diseases and may also have relevant implications in sports shoe design. This study is a preliminary investigation for our ultimate goal to develop an effective treatment method by developing an autonomous GRF manipulations device based on closed-loop feedback.

Reduction of hip joint reaction force via medio-lateral foot center of pressure manipulation in bilateral hip osteoarthritis patients.

Loading/excessive loading of the hip joint has been linked to onset and progression of hip osteoarthritis. Footwear-generated biomechanical manipulation in the frontal plane has been previously shown in a cohort of healthy subjects to cause a specific gait adaption when the foot center of pressure trajectory was shifted medially, which thereby significantly reduced hip joint reaction force. The objective of the present study was to validate these results in a cohort of female bilateral hip osteoarthritis patients. Sixteen patients underwent gait analysis while using a footworn biomechanical device, allowing controlled foot center of pressure manipulation, in three para-sagittal configurations: medial, lateral, and neutral. Hip osteoarthritis patients exhibited similar results to those observed in healthy subjects in that a medial center of pressure led to an increase in inter-maleolar distance while step width (i.e., distance between right and left foot center of pressure) remained constant. This adaptation, which we speculate subjects adopt to maintain base of support, was associated with significantly greater hip abduction, significantly decreased hip adduction moment, and significantly reduced joint reaction force compared to the neutral and lateral configurations. Recommendations for treatment of hip osteoarthritis emphasize reduction of loads on the pathological joint(s) during daily activities and especially in gait. Our results show that a medially deviated center of pressure causes a reduction in hip joint reaction force. The present study does not prove, but rather suggests, clinical significance, and further investigation is required to assess clinical implications. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1762-1771, 2016.

Alteration of the foot center of pressure trajectory by an unstable shoe design.

BACKGROUND: Unstable sole designs have been used as functional or therapeutic tools for improving body stability during locomotion. It has been suggested that the narrow base of support under the feet generate perturbations that challenge the instability of different joints during motion, thereby forcing the body to modify its movement in order to maintain a stable gait. The purpose of the present study was to explore the correlation between the stability of the footwear-device and the magnitude of perturbation conveyed during gait. METHODS: Various levels of dynamic instability were achieved using a novel foot-worn platform with two adjustable convex rubber elements attached to its sole. A total of 20 healthy male adults underwent direct in-shoe pressure measurements while walking with the footwear device. Foot center of pressure (COP) and stride to stride variability measures were extracted to examine the correlation between the magnitude of the instability and the imposed perturbations during gait. RESULTS: A counterintuitive but significant correlation was found between stride to stride variability and the instability of the biomechanical elements. Moreover, there was significant correlation between the instability of the elements and the perturbations found in the COP trajectory. The linear model describing this correlation was found to be statistically significant. CONCLUSION: There was significantly negative correlation between the level of instability induced by the shoe design and the amount of perturbations conveyed during gait. This suggests that the external perturbation must remain within a certain range limit. Exceeding this limit can negatively affect the treatment and probably lead to opposite results.

Gait characteristics and quality of life perception of patients following tibial plateau fracture.

INTRODUCTION: The purpose of the current study was to evaluate the long-term functional outcome as measured by gait patterns and quality of life assessment of patients with high-energy tibial plateau fracture compared to matched controls. MATERIALS AND METHODS: Thirty-eight patients were evaluated in a case-controlled comparison. Twenty-two patients with tibial plateau fracture were evaluated after 3.1 (1.63) years (sd) from injury. Patients underwent a computerized spatiotemporal gait test and completed the SF-12 health survey. 16 healthy subjects, matched for age and gender served as a control group. The main outcome measures for this study were spatiotemporal gait characteristics, physical quality of life and mental quality of life. RESULTS: Significant differences were found in all gait parameters between patients with tibial plateau fracture and healthy controls. Patients with tibial plateau fracture walked slower by 18% compared to the control group (p < 0.001), had slower cadence by 8% compared (p = 0.002) to the control group and had shorter step length in the involved leg by 11% and in the uninvolved leg by 12% compared to the control group (p = 0.006 and p = 0.003, respectively). Patients with tibial plateau fracture also showed shorter single limb support (SLS) in the involved leg by 12% compared to the uninvolved leg and 5% in the uninvolved leg compared to the control group (p < 0.001 and p = 0.017, respectively). Significant differences were found in the Short Form (SF)-12 scores. Physical Health Score of patients with tibial plateau fracture was 65% lower compared to healthy controls (p < 0.001), and Mental Health Score of the patients was 40% lower compared to healthy controls (p < 0.001). Finally, significant correlations were found between SF-12 and gait patterns. CONCLUSION: Long-term deviations in gait and quality of life exist in patients following tibial plateau fracture. Patients following tibial plateau fracture present altered spatiotemporal gait patterns compared to healthy controls, as well as self-reported quality of life.

Frontal plane biomechanics of the operated and non-operated knees before and after unilateral total knee arthroplasty.

BACKGROUND: After unilateral total knee arthroplasty, frontal plane loading patterns on the operated knee remain pathological in the long term, but it is unclear how they change in the early postoperative period. Additionally, researchers have suggested that the non-operated knee bears greater frontal plane loads postoperatively, but this effect is unclear. The objective of the present study was to compare the preoperative and early postoperative frontal plane loading patterns of both knees after unilateral total knee arthroplasty. METHODS: Fifty patients with end-stage knee osteoarthritis were examined prior to and six weeks after surgery. Patients underwent a three-dimensional gait analysis that determined the frontal plane loading patterns of knee varus angle and knee adduction moment during gait, and completed self-evaluative questionnaires and functional tests. FINDINGS: There were no significant loading differences between limbs preoperatively. The operated knee showed large reductions in varus angle and adduction moment after surgery (all p<0.001). The non-operated knee showed no increases in varus angle or adduction moment, but did show a small reduction in the adduction moment (p<0.001). Both knees showed reduction in pain after surgery (p<0.001) and the operated Knee Society Score improved after surgery (p=0.01). INTERPRETATION: Total knee arthroplasty reduces frontal plane loading in the operated knee and does not worsen frontal plane loading in the non-operated knee. Therapy after surgery should focus on retaining the reduction in knee adduction moment in the operated knee and preventing further worsening loading patterns in the non-operated knee.

Deviations in gait metrics in patients with chronic ankle instability: a case control study.

BACKGROUND: Gait metric alterations have been previously reported in patients suffering from chronic ankle instability (CAI). Previous studies of gait in this population have been comprised of relatively small cohorts, and the findings of these studies are not uniform. The objective of the present study was to examine spatiotemporal gait metrics in patients with CAI and examine the relationship between self-reported disease severity and the magnitude of gait abnormalities. METHODS: Forty-four patients with CAI were identified and compared to 53 healthy controls. Patients were evaluated with spatiotemporal gait analysis via a computerized mat and with the Short Form (SF) - 36 health survey. RESULTS: Patients with CAI were found to walk with approximately 16% slower walking velocity, 9% lower cadence and approximately 7% lower step length. Furthermore, the base of support, during walking, in the CAI group was approximately 43% wider, and the single limb support phase was 3.5% shorter compared to the control group. All of the SF-36 8-subscales, as well as the SF-36 physical component summary and SF-36 mental component summary, were significantly lower in patients with CAI compared to the control group. Finally, significant correlations were found between most of the objective gait measures and the SF-36 mental component summary and SF-36 physical component summary. CONCLUSIONS: The results outline a gait profile for patients suffering from CAI. Significant differences were found in most spatiotemporal gait metrics. An important finding was a significantly wider base of support. It may be speculated that these gait alterations may reflect a strategy to deal with imbalance and pain. These findings suggest the usefulness of gait metrics, alongside with the use of self-evaluation questionnaires, in assessing disease severity of patients with CAI.

The correlation between radiographic knee OA and clinical symptoms--do we know everything?

UNLABELLED: This study aims to evaluate the correlations between common clinical osteoarthritis (OA) diagnostic tools in order to determine the value of each. A secondary goal was to investigate the influence of gender differences on the findings. Five hundred and eighteen patients with knee OA were evaluated using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire, short form 36 (SF-36) Health Survey, and plain radiographs. Analysis of variance (ANOVA) was used to compare the different domains of the WOMAC and SF-36 questionnaires between genders and the radiographic scale. Higher knee OA x-ray grade were associated with worse clinical outcome: for women, higher scores for the WOMAC pain, function and final scores and lower scores in the SF-36 final score; in men, lower SF-36 overall and physical domains scores. Gender differences were found in all clinical scores that were tested, with women having worse clinical scores for similar radiographic grading (p values <0.001). Knee radiographs for OA have an important role in the clinical evaluation of the patient. Patients with higher levels of knee OA in x-ray have a higher probability of having a worse clinical score in the WOMAC and SF-36 scores. The gender differences suggest that for similar knee OA x-ray grade, women's clinical scores are lower. TRIAL REGISTRATION: NCT00767780.

Alterations in sagittal plane knee kinetics in knee osteoarthritis using a biomechanical therapy device.

Knee frontal (adduction/abduction) and sagittal (flexion/extension) moments have been implicated in the pathomechanics of knee osteoarthritis (OA). The aim of this study was to evaluate the change in the knee sagittal moment in a cohort of patients with knee OA undergoing a biomechanical training program. Twenty-five female patients with symptomatic medial compartment knee OA were enrolled in a customized biomechanical intervention program. All patients underwent consecutive gait analyses prior to treatment initiation, and after 3 months and 9 months of therapy. Self-evaluative questionnaires, spatiotemporal gait parameters, peak knee sagittal moments, knee sagittal impulses, and duration of knee moments were compared throughout the duration of therapy. Differences between baseline and follow-up values were examined using nonparametric tests. Peak knee flexion moment (KFM) at loading response decreased significantly with therapy (p = 0.001). Duration of KFM and impulse of knee flexion also decreased significantly (p = 0.024 and p = 0.029, respectively). These changes were accompanied by increased walking velocity, significant pain reduction, and increased functional activity. Post-training kinetic evaluation demonstrated profound alterations of knee sagittal moments at the loading response KFM. We speculate that knee sagittal moments can potentially be improved in patients with knee OA over time with a biomechanical training program.

Reduction of frontal-plane hip joint reaction force via medio-lateral foot center of pressure manipulation: a pilot study.

Footwear-generated biomechanical manipulation of lower-limb joints has been shown to influence lower-limb biomechanics. Numerous studies report the influence of such interventions on the knee, however little is known about the influence of these interventions on the hip. The present study analyzed kinetic and kinematic changes about the hip of 12 healthy young males who underwent biomechanical manipulation utilizing the APOS biomechanical device (APOS-Medical and Sports Technologies Ltd., Herzliya, Israel) allowing controlled foot center of pressure manipulation. Subjects underwent gait testing in four para-sagittal device configurations: Medial, lateral, neutral, and regular shoes. In the medial configuration, subjects demonstrated no change in step width (i.e., distance between right and left foot center of pressure), however inter-malleolar distance significantly increased. Likewise with the medial setting, greater hip abduction was recorded, while hip adduction moment and joint reaction force decreased significantly. We speculate that subjects adopt a modified gait pattern aimed to maintain constant base of support. As a result, hip abductor muscle moment arm increases and adduction moment and joint reaction force decreases. To the best of our knowledge this is the first study to show this relationship. These results contribute to the understanding of lower-limb biomechanics and warrant further investigation.

Mortality and reoperations following lower limb amputations.

BACKGROUND: Above-the-knee amputations (AKA) and below-the-knee amputations (BKA) are commonly indicated in patients with ischemia, extensive tissue loss, or infection. AKA were previously reported to have better wound-healing rates but poorer rehabilitation rates than BKA. OBJECTIVES: To compare the outcomes of AKA and BKA and to identify risk factors for poor outcome following leg amputation. METHODS: This retrospective cohort study comprised 188 consecutive patients (mean age 72 years, range 25-103, 71 males) who underwent 198 amputations (91 AKA, 107 BK 10 bilateral procedures) between February 2007 and May 2010. Included were male and female adults who underwent amputations for ischemic, infected or gangrenotic foot. Excluded were patients whose surgery was performed for other indications (trauma, tumors). Mortality and reoperations (wound debridement or need for conversion to a higher levelof amputation) were evaluated as outcomes. Patient- and surgery-related risk factors were studied in relation to these primary outcomes. RESULTS: The risk factors for mortality were dementia [hazard ratio (HR) 2.769], non-ambulatory status preoperatively (HR 2.281), heart failure (HR 2.013) and renal failure (HR 1.87). Resistant bacterial infection (HR 3.083) emerged as a risk factor for reoperation. Neither AKA nor BKA was found to be an independent predictor of mortality or reoperation. CONCLUSIONS: Both AKA and BKA are associated with very high mortality rates. Mortality is most probably related to serious comorbidities (renal and heart disease) and to reduced functional status and dementia. Resistant bacterial infections are associated with high rates of reoperation. The risk factors identified can aid surgeons and patients to better anticipate and possibly prevent severe complications.

Foot center of pressure trajectory alteration by biomechanical manipulation of shoe design.

BACKGROUND: Footwear-generated biomechanical manipulations have been shown to alter lower limb kinetics. It has been suggested that this is due to altered trajectory of the foot's center of pressure (COP), conveying a shift in location of the ground reaction force and modifying moments and forces acting on proximal body segments. However, past studies have focused on qualitative association between footwear design and the COP locus. Moreover, this association was calculated via indirect analysis. The purpose of the present study was to directly examine and quantify the correlation between measured footwear biomechanical manipulation and the location of the COP trajectory during gait. METHODS: A novel biomechanical device allowing flexible positioning of 2 convex-shaped elements attached to its sole was utilized. A total of 20 healthy male adults underwent direct in-shoe pressure measurements while walking with the device set at 7 mediolateral configurations. COP data were collected during gait and analyzed with respect to different stance subphases. RESULTS: COP location significantly correlated with a shift of the elements medially or laterally. The linear model describing this correlation was found to be statistically significant. CONCLUSION: There was significant correlation between the plantar orientation of the shoe device configuration and the COP. CLINICAL RELEVANCE: Changes in COP trajectory may be valuable in patients suffering from multiple foot disorders elevating pressure on the foot. Accurate COP control could aid in the manipulation of the forces acting on the proximal joints during gait. In addition, these findings may have implications in the field of biomechanical apparatus design and practice.

The outcome of a novel biomechanical therapy for patients suffering from anterior knee pain.

BACKGROUND: This study was devised to examine the effect of a novel biomechanical therapy for patients suffering from anterior knee pain (AKP). METHODS: A retrospective analysis of 48 patients suffering from AKP was performed. Patients underwent a gait evaluation, using an electronic walkway mat, and completed the SF-36 health survey and the WOMAC questionnaire at baseline and after 3 and 6months of therapy. A special biomechanical device was individually calibrated for each patient. AposTherapy is a functional, non-invasive rehabilitation therapy consisting of a biomechanical foot-worn device that is used during activities of daily living. Repeated measures analyses were performed to compare gait parameters and self-evaluation questionnaires between baseline, 3months and 6months. RESULTS: Walking velocity significantly increased by 5.7cm/s, cadence increased by 1.6 steps/minute, and stride length increased by 3.4cm in relation to pretreatment testing (p<0.001 for all). End-point evaluation revealed additional improvement of these parameters; however these did not significantly differ from that of mid-treatment. Pain decreased by 36.6% and 49.2% following 13 and 26 weeks of treatment, respectively (P<0.01) and function improved by 25.2% and 41.7% following 13 and 26 weeks of treatment, respectively (P=0.01). CONCLUSIONS: Based on the current study's results it may be concluded that this therapy might have a positive effect for patients with AKP.

Gait metric profile of 157 patients suffering from anterior knee pain. A controlled study.

PURPOSE: Gait metric alterations have been previously reported in patients suffering from anterior knee pain (AKP). Characterization of simple and measureable gait parameters in these patients may be valuable for assessing disease severity as well as for follow-up. Previous gait studies in this population have been comprised of relatively small cohorts and the findings of these studies are not uniform. The objective of the present study was to examine spatio-temporal gait parameters in patients with AKP in comparison to symptom-free controls. Furthermore, the study aimed to examine the relationship between self-reported disease severity and the magnitude of gait abnormalities. METHODS: 157 patients with AKP were identified and compared to 31 healthy controls. Patients were evaluated with a spatiotemporal gait analysis via a computerized mat, the Western Ontario and McMaster Osteoarthritis Index (WOMAC) questionnaire and the Short Form (SF)-36 health surveys. RESULTS: AKP patients walked with significantly lower velocity (15.9%) and cadence (5.9%), shorter step length (9.5%), stride length (9.6%), and showed significant differences in all gait cycle phases (P<0.05 for all). Study group reported higher levels of pain (96%), functional limitation (94%), and poorer perception of mental quality of life (30%) (P<0.05 for all). CONCLUSION: Significant differences were found between the spatiotemporal gait profile of AKP patients and symptom-free matched controls. In addition, an association was found between subjective disease severity and gait abnormalities. These findings suggest the usefulness of gait parameters, alongside with the use of self-evaluation questionnaires, in identifying deviations of these patients from healthy population.

In-shoe center of pressure: indirect force plate vs. direct insole measurement.

BACKGROUND: In-shoe center of pressure (COP) measurement is essential in biomechanics. COP can be measured directly utilizing pressure-sensitive insoles, or calculated indirectly via force plate-generated data. While the latter does not require the use of additional measurement hardware (shoe insoles), its precision at calculating in-shoe COP has not been determined. Our purpose was to ascertain the precision of force plate in-shoe COP calculations and enhance their accuracy through a mathematical algorithm. METHODS: Twelve male students participated in the study. In-shoe COP was measured synchronously via the Pedar-X insole system and AMTI force plates, comparing the measurements of both systems. A mathematical algorithm was created to improve agreement between the systems and comparisons were recalculated. RESULTS: The two methods showed different measurements of in-shoe COP. The medio-lateral (ML) and anterior-posterior (AP) Pearson correlation coefficients between systems were 0.44 ± 0.35 and 0.99 ± 0.01, and the ML and AP RMS errors were 6.3 ± 3.0 mm and 43.0 ± 12.5 mm, respectively. Using a mathematical algorithm, the differences between the measurements of each system could be reduced significantly (all P<0.001). CONCLUSIONS: Without adjustment, force plates give an approximate location of the COP. Using an adjustment model greatly improves the accuracy of the COP trajectory during stance.

Detecting and quantifying global instability during a dynamic task using kinetic and kinematic gait parameters.

OBJECTIVES: Instability during gait can be identified in many different ways. Recent studies have suggested utilizing spatiotemporal parameters to detect instability during gait. Detecting instability using kinetic and kinematic gait parameters has not yet been examined fully. In addition, these studies have not yet identified measures that are capable of assessing the magnitude of instability. The objective of the present study was to identify kinetic and kinematic gait parameters that can best identify instability and quantify its magnitude. METHODS: Ten healthy men underwent successive gait analysis testing under three controlled settings: (1) Stage 0 instability (control setting), (2) Stage 1 instability and (3) Stage 2 instability. The levels of instability were precisely applied with the use of a controlled perturbation device (AposTherapy System). Differences between all stages and between stages were identified using Friedman and Wilcoxon tests. RESULTS: Stride-to-stride variability (STSV) in kinetic and kinematic measures increased significantly between stages 0 and 1 or between stages 0 and 2 for almost all parameters (all P<0.05). A significant increase between stage 0 and both stages 1 and 2 was found for knee flexion moment, knee varus moment, knee flexion angle and hip adduction angle. The increase between stages 1 and 2 was variable. Only the knee varus moment parameter showed a significant increase in STSV between stages 1 and 2 (P=0.026). CONCLUSIONS: Almost all kinetic and kinematic gait parameters are sensitive to changes in global instability in a dynamic task. The most sensitive are parameters measured at the knee. Of these, STSV in knee varus moment can be used to quantify the magnitude of dynamic instability.

Reduction in knee adduction moment via non-invasive biomechanical training: a longitudinal gait analysis study.

Biomechanical non-invasive interventions have been previously reported to reduce pain and facilitate superior levels of function in patients with medial knee osteoarthritis [OA]. One such treatment is the AposTherapy, a customized program utilizing a foot-worn biomechanical device allowing center of pressure modification and continuous perturbation during gait. The influence of this intervention on objective gait metrics has yet to be determined. The aim of the current study was to prospectively examine changes in kinetic and kinematic parameters in patients enrolled in this treatment program. Twenty-five females with symptomatic bilateral medial compartment knee OA were enrolled in the customized daily treatment program. All patients underwent barefoot gait analysis testing and completed subjective questionnaires prior to treatment initiation and on two follow-up visits. Significantly reduced knee adduction moment (KAM) magnitude was noted during barefoot walking after three and nine months of treatment. On average, the knee adduction impulse and the 1st and 2nd KAM peaks were reduced by 13%, 8.4%, and 12.7%, respectively. Furthermore, moment reduction was accompanied by elevated walking velocity, significant pain reduction, and increased functional activity. In addition to symptomatic improvement, our results suggest that this treatment program can alter kinetic gait parameters in this population. We speculate that these adaptations account for the symptomatic and functional improvement reported for this intervention.

Can single limb support objectively assess the functional severity of knee osteoarthritis?

There is a lack in objective measurements that can assess the symptoms of knee osteoarthritis (KOA). In a previous study it was shown that pain and function are in higher correlation with the single-limb support gait parameter than with radiographic KOA stage. Single limb support represents a phase in the gait cycle when the body weight is entirely supported by one limb, while the contra-lateral limb swings forward. The purpose of this study was to further examine the relationship between single-limb support and the level of pain and function in patients with KOA. 125 adults with bilateral KOA underwent a physical and radiographic evaluation, and completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the SF-36 health survey. Patients walked barefoot at a self-selected speed on a computerized mat. Statistical analysis was used to divide the patients into quintiles based on single-limb support phase value and determine the differences in WOMAC and SF-36 scores between quintiles. Significant differences were found in WOMAC and SF-36 sub-category scores between the single-limb support quintiles. The means of the WOMAC-pain and WOMAC-function sub-categories decreased gradually over single-limb support quintiles (P<0.001), and the means of the SF-36 sub-categories increased gradually over the quintiles (P<0.001). Results show that single-limb support quintiles can help determine the level of pain, function and quality of life in patients with KOA. These results suggest that single-limb support quintiles may be added as an additional scale for generally assessing the symptomatic stage of KOA.

Extensor mechanism reconstruction: a novel technique for bone patella allograft post partial patellectomy failure.

Extensor mechanism disruption, whether due to patella fracture or tendon rupture, generally occurs after low-energy trauma and frequently involves an indirect mechanism. When the fracture is comminuted and reconstruction is impossible, a partial or total patellectomy may be indicated. Although some authors advocate total patellectomy, partial patellectomy remains the standard treatment, especially for young and active patients. In the rare instance of a failed tendon repair after partial or total patellectomy, inadequate tissue is usually available for adequate restoration of the extensor mechanism. Extensor mechanism allograft, using the tibial tuberosity, patellar tendon, patella, and quadriceps tendon in continuity or the Achilles' tendon with calcaneal bone-block in continuity has been reported for extensor mechanism repair after total knee arthroplasty in patients who did not undergo patellectomy. We present a novel technique, using the bone patellar tendon bone allograft to reconstruct a posttraumatic defect of the extensor mechanism in a 28-year-old, active patient with a failed partial patellectomy following fracture of his patella. Union of the allograft was seen on x-ray after 4 months. After 6 months, the patient reached full range of motion and returned to his previous sporting activities.