The Effect of Total Knee Replacement on Dual-Task Gait Performance in Older Adults.

OBJECTIVE: Total knee replacement (TKR) is a common solution for patients with advanced knee osteoarthritis. Still, fall rates remain relatively high after surgery. TKR may alter pain and knee function, balance control, and proprioception. However, given the role of complex (dual-task) walking in fall prediction for older adults, it is unknown how TKR alters the attentional demand of walking in older adults. The goal of this study was to examine the effect of TKR on dual-task walking among older adults. METHODS: Participants were evaluated 1 month before surgery and 4.5 months after surgery. Participants walked along an instrumented 7-meter path for 1 minute with and without a cognitive task (serial-3 subtraction). Pain and knee function, knee proprioception, dynamic balance, and balance confidence, as well as dual-task costs (DTC) were compared before and after the surgery and factors associated with change in gait DTCs were assessed. RESULTS: Thirty-eight participants completed the study (age 72.6 years, SD = 4.9; 11 men). A significant decrease in pain was found following TKR, with no change in balance, balance confidence, or proprioception. There were no differences in gait DTCs before and after the surgery. However, change in dynamic balance, specifically reactive postural control and dynamic gait, predicted changes in gait speed and stride time DTCs. CONCLUSION: The absence of an effect of TKR on gait DTCs can potentially underlie increased fall risk after TKR. Results from this study emphasize the significance of balance as a measure and focal point for rehabilitation after TKR. IMPACT: This study contributes to our understanding of the attentional cost of walking in people before and after TKR, as well as to factors associated with it. Results from this work can assist formulation of rehabilitation programs for people with knee osteoarthritis.

Outcomes of Osteoid Osteoma Treated by Percutaneous CT-Guided Radiofrequency Ablation.

Introduction Osteoid osteomas are the most frequent true benign bone tumor in the adolescent age group and the third most prevalent benign bone tumor overall. This study was designed to assess the effectiveness of the procedure and correlate it with the analgesia offered because of the significant burden of this illness and new literature supporting the successful outcomes of image-guided percutaneous radiofrequency ablation (RFA) in osteoid osteoma. Methodology  This hospital-based interventional trial was carried out in a tertiary care referral center. Forty-two patients with osteoid osteoma, ranging in age from 9 to 30, were included in the study. The patients received RFA guided by computed tomography (CT), and they were postoperatively monitored at one, two, and four weeks and three, six months, and 12 months. A numerical pain scale (NPS) was used to evaluate the patient's pain both before and after the procedure. The preoperative and postoperative results were contrasted. Results A total of 42 participants were enrolled in the study. Eight (19.05%) women and 34 (80.95%) men made up the group. Complete pain alleviation (NPS=0) was attained in 42.8% and 96.4% of the study group in the first and second weeks post-procedure. Almost all patients began protected weight-bearing at one week, according to their level of pain tolerance. Osteoid osteoma of the talus was a remnant lesion in one patient that required further treatment after two weeks. During the duration of the follow-up, no problems were recorded. Conclusion Percutaneous CT-guided RFA of osteoid osteoma is a safe, minimally invasive procedure and greatly reduces the duration of hospitalization. It has excellent functional outcomes and no known complications.

Association Between Knee Osteoarthritis and Functional Changes in Ankle Joint and Achilles Tendon.

Increasing evidence has shown that biomechanical forces often drive the progression of knee osteoarthritis (OA). Attention should be given to the changes in adjacent joints and their relation to knee OA. The purpose of the present study was to examine the changes in Achilles tendon thickness of individuals with knee OA and to evaluate the correlation between Achilles tendon thickness and knee OA severity in a case-control prospective observational study. A total of 93 participants with no previous ankle injuries were recruited. Of the 93 participants, 63 had knee OA of the medial compartment and 30 served as controls. The subjects underwent a clinical examination that included measurements of weight, height, Achilles tendon thickness, and 1-leg heel rise. The subjects also underwent a computerized gait test and completed the Hebrew version of the Western Ontario and McMaster Osteoarthritis Index and 36-item short-form (SF-36) health survey. Significant difference was found in Achilles tendon thickness between the subjects with knee OA and the healthy controls (17.1 ± 3.4 versus 15.1 ± 3.1; p = .009). Significant differences were also found between the 2 groups in the 1-leg heel rise test, Western Ontario and McMaster Osteoarthritis Index scores, SF-36 scores, and all gait measures. Significant correlations were found between the Achilles tendon thickness and the following measures: weight (r = 0.46), body mass index (r = 0.55), Kellgren and Lawrence OA severity grade (r = 0.25), 1-leg heel rises (r = -0.50), and SF-36 score (r = -0.25). Subjects with knee OA presented with a thicker Achilles tendon compared with the healthy controls. Furthermore, a significant correlation between Achilles tendon thickness and knee OA severity was found. A comprehensive assessment of the Achilles tendon and ankle joint should be a part of the knee OA evaluation process.

A non-invasive, home-based biomechanical therapy for patients with spontaneous osteonecrosis of the knee.

BACKGROUND: The purpose of the current study was to examine the effect of a non-invasive, home-based biomechanical treatment program for patients with spontaneous osteonecrosis of the knee (SONK). METHODS: Seventeen patients with SONK, confirmed by MRI, participated in this retrospective analysis. Patients underwent a spatiotemporal gait analysis and completed the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the Short-Form-36 (SF-36). Following an initial assessment, patients commenced the biomechanical treatment (AposTherapy). All patients were reassessed after 3 and 6 months of treatment. RESULTS: A significant reduction in pain and improvement in function was seen after 3 months of therapy with additional improvement after 6 months of therapy. Pain was reduced by 53% and functional limitation reduced by 43%. Furthermore, a significant improvement was also found in the SF-36 subscales, including the summary of physical and mental scores. Significant improvements were found in most of the gait parameters including a 41% increase in gait velocity and a 22% increase in step length. Patients also demonstrated improvement in limb symmetry, especially by increasing the single limb support of the involved limb. CONCLUSIONS: Applying this therapy allowed patients to be active, while walking more symmetrically and with less pain. With time, the natural course of the disease alongside the activity of the patients with the unique biomechanical device led to a significant reduction in pain and improved gait patterns. Therefore, we believe AposTherapy should be considered as a treatment option for patients with SONK. TRIAL REGISTRATION: Assaf Harofeh Medical Center Institutional Helsinki Committee Registry, 141/08; ClinicalTrials.gov NCT00767780 .

Lower Extremity Kinematic Profile of Gait of Patients After Ankle Fracture: A Case-Control Study.

The present study examined the differences in the lower extremity gait kinematic profile of patients recovering from ankle fracture compared with healthy controls. In addition, we inquired whether the profile would differ among fracture severity groups. A total of 48 patients participated in the present prospective, case-control study. The gait of 24 patients recovering from an ankle fracture injury and 24 healthy matched controls was examined using an inertial measurement unit sensor system. The following gait parameters were evaluated: knee range of motion (ROM) during the swing phase, maximum knee flexion angle during stance, thigh and calf ROM, and stride duration. Statistically significant differences were found between the ankle fracture group and the control group for all parameters. The patients with ankle fracture had a lower knee ROM during swing phase compared with the control group (mean ± standard deviation 43.0° ± 15.5° compared with 66.7° ± 5.1°, respectively; p < .001). The maximum knee flexion angle during stance was lower in the patients with ankle fracture than in the control group (mean ± standard deviation 10.5° ± 6.1° compared with 21.2° ± 4.5°, respectively; p < .001). Patients with ankle fracture also had lower gait cycle thigh and calf ROM angles (p < .001) and a longer stride duration (p < .001) compared with the control group. No statistically significant differences were found among the severity groups. These results suggest that the gait kinematic characteristics vary between healthy people and patients recovering from an ankle fracture injury during the short-term period after injury.

A Novel Non-Invasive Adjuvant Biomechanical Treatment for Patients with Altered Rehabilitation after Total Knee Arthroplasty: Results of a Pilot Investigation.

BACKGROUND: Many factors contribute to suboptimal results after total knee arthroplasty (TKA) but little is known regarding the value of postsurgical rehabilitation after TKA. We examined the effects of an enhanced closed kinematic chain exercises program (AposTherapy) on gait patterns and clinical outcomes among patients with a lack of progress in their postsurgical rehabilitation. METHODS: Twenty-two patients were prospectively followed during the study. Gait spatiotemporal parameters were measured at the initial evaluation, after 15 minutes of therapy, and after 3 months of therapy. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the short form (SF) 36 health survey were completed by patients before treatment and after 3 months of treatment. RESULTS: The WOMAC and SF-36 scores improved significantly after 3 months of treatment. Gait velocity, single limb support, and step length of the operated leg improved significantly even after a single 15 minutes treatment. Normal gait velocity was observed in 36% of patients after 3 months of treatment. CONCLUSIONS: A physiotherapy program that included enhanced closed kinematic chain biomechanical therapy was beneficial for patients who experienced a suboptimal rehabilitation course after TKA.

Patients with knee osteoarthritis demonstrate improved gait pattern and reduced pain following a non-invasive biomechanical therapy: a prospective multi-centre study on Singaporean population.

BACKGROUND: Previous studies have shown the effect of a unique therapy with a non-invasive biomechanical foot-worn device (AposTherapy) on Caucasian western population suffering from knee osteoarthritis. The purpose of the current study was to evaluate the effect of this therapy on the level of symptoms and gait patterns in a multi-ethnic Singaporean population suffering from knee osteoarthritis. METHODS: Fifty-eight patients with bilateral medial compartment knee osteoarthritis participated in the study. All patients underwent a computerized gait test and completed two self-assessment questionnaires (WOMAC and SF-36). The biomechanical device was calibrated to each patient, and therapy commenced. Changes in gait patterns and self-assessment questionnaires were reassessed after 3 and 6 months of therapy. RESULTS: A significant improvement was seen in all of the gait parameters following 6 months of therapy. Specifically, gait velocity increased by 15.9%, step length increased by 10.3%, stance phase decreased by 5.9% and single limb support phase increased by 2.7%. In addition, pain, stiffness and functional limitation significantly decreased by 68.3%, 66.7% and 75.6%, respectively. SF-36 physical score and mental score also increased significantly following 6 months of therapy (46.1% and 22.4%, respectively) (P < 0.05 for all parameters). CONCLUSIONS: Singaporean population with medial compartment knee osteoarthritis demonstrated improved gait patterns, reported alleviation in symptoms and improved function and quality of life following 6 months of therapy with a unique biomechanical device. TRIAL REGISTRATION: Registration number NCT01562652.

A noninvasive biomechanical treatment as an additional tool in the rehabilitation of an acute anterior cruciate ligament tear: A case report.

OBJECTIVES: Conservative treatments for anterior cruciate ligament (ACL) tears may have just as good an outcome as invasive treatments. These include muscle strengthening and neuromuscular proprioceptive exercises to improve joint stability and restore motion to the knee. The Purpose of the current work presents was to examine the feasibility of a novel non-invasive biomechanical treatment to improve the rehabilitation process following an ACL tear. This is a single case report that presents the effect of this therapy in a patient with a complete ACL rupture who chose not to undergo reconstructive surgery. METHODS: A 29-year old female athlete with an acute indirect injury to the knee who chose not to undergo surgery was monitored. Two days after injury the patient began AposTherapy. A unique biomechanical device was specially calibrated to the patient's feet. The therapy program was initiated, which included carrying out her daily routine while wearing the device. The subject underwent a gait analysis at baseline and follow-up gait analyses at weeks 1, 2, 4, 8, 12 and 26. RESULTS: A severe abnormal gait was seen immediately after injury, including a substantial decrease in gait velocity, step length and single limb support. In addition, limb symmetry was substantially compromised following the injury. After 4 weeks of treatment, patient had returned to normal gait values and limbs asymmetry reached the normal range. CONCLUSIONS: The results of this case report suggest that this conservative biomechanical therapy may have helped this patient in her rehabilitation process. Further research is needed in order to determine the effect of this therapy for patients post ACL injuries.

A non-invasive biomechanical device and treatment for patients following total hip arthroplasty: results of a 6-month pilot investigation.

BACKGROUND: The purpose of the study was to examine the effect of a foot-worn biomechanical device on the clinical measurements and gait patterns of patients with total hip arthroplasty (THA). METHODS: Nineteen patients, up to 3 months post-THA, were enrolled to the study. Patients underwent a computerized gait analysis to calculate spatiotemporal parameters and completed the Western Ontario and McMaster Universities osteoarthritis index and the SF-36 health survey. Patients then began therapy with a non-invasive foot-worn biomechanical device coupled with a treatment methodology (AposTherapy). Patients received exercise guidelines and used the device daily during their regular activities at their own environment. Follow-up examinations were conducted after 4, 12, and 26 weeks of therapy. Repeated measures ANOVA was used to evaluate changes over time. The clinical significance of the treatment effect was evaluated by computing the Cohen's effect sizes (ES statistic). RESULTS: After 26 weeks of therapy, a significant improvement was seen in gait velocity (50.3%), involved step length (22.9%), and involved single limb support (16.5%). Additionally, a significant reduction in pain (85.4%) and improvement in function (81.1%) and quality of life (52.1%) were noted. CONCLUSIONS: Patients following THA demonstrated a significant improvement in gait parameters and in self-assessment evaluations of pain, function, and quality of life. We recommend further RCTs to examine the effect of this therapy compared to other rehabilitation modalities following THA and compared to healthy matched controls. TRIAL REGISTRATION: Clinical trial registration number NCT01266382.

A unique foot-worn device for patients with degenerative meniscal tear.

PURPOSE: The purpose of the current study was to assess the effects of a new foot-worn device on the gait, physical function and pain in patients suffering from knee osteoarthritis (OA) who had a low-impact injury to the medial meniscus causing a degenerative meniscal tear. METHODS: A retrospective analysis of 34 patients with knee OA and a degenerative medial meniscal tear 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 12 months of therapy. AposTherapy is a functional, biomechanical, non-invasive rehabilitation therapy consisting of a foot-worn device that is individually calibrated to each patient and is used during activities of daily living. Repeated-measures analyses were performed to compare gait parameters and self-evaluation questionnaires between baseline, and 3 and 12 months. RESULTS: Significant improvements were found in gait velocity, step length and single-limb support of the involved knee following 12 weeks of therapy (all p < 0.01), alongside an improvement in limb symmetry. These results were maintained at the 12-month follow-up examination. Significant improvements were also found in all three domains of the WOMAC index (pain, stiffness and physical function) and in the SF-36 Physical Health Scale and the SF-36 Mental Health Scale (all p < 0.01). CONCLUSIONS: Patients with knee OA and a degenerative medial meniscal tear using a biomechanical foot-worn device for a year showed improvement in gait, physical function and pain. Based on the findings of this study, it can be postulated that this biomechanical device might have a positive effect on this population. LEVEL OF EVIDENCE: Therapeutic study, Level IV.

Mimicking the structure of the V3 epitope bound to HIV-1 neutralizing antibodies.

The third variable region (V3) of the HIV-1 envelope glycoprotein gp120 is a target for virus neutralizing antibodies. The V3 sequence determines whether the virus will manifest R5 or X4 phenotypes and use the CCR5 or CXCR4 chemokine coreceptor, respectively. Previous NMR studies revealed that both R5- and X4-V3 peptides bound to antibodies 0.5beta and 447-52D form beta-hairpin conformations with the GPGR segment at the turn. In contrast, in their free form, linear V3 peptides and a cyclic peptide consisting of the entire 35-residue V3 loop were highly unstructured in aqueous solution. Herein we evaluated a series of synthetic disulfide constrained V3-peptides in which the position of the disulfide bonds, and therefore the ring size, was systematically varied. NMR structures determined for singly and doubly disulfide constrained V3-peptides in aqueous solution were compared with those found for unconstrained V3(JRFL) and V3(IIIB) peptides bound to 447-52D and to 0.5beta, respectively. Our study indicated that cyclic V3 peptides manifested significantly reduced conformational space compared to their linear homologues and that in all cases cyclic peptides exhibited cross-strand interactions suggestive of beta-hairpin-like structures. Nevertheless, the singly constrained V3-peptides retained significant flexibility and did not form an idealized beta-hairpin. Incorporation of a second disulfide bond results in significant overall rigidity, and in one case, a structure close to that of V3(MN) peptide bound to 447-52D Fab was assumed and in another case a structure close to that formed by the linear V3(IIIB) peptide bound to antibody 0.5beta was assumed.