Comparison of Immediate Effect of New Knee brace and Conventional Three-Points Knee Valgus Brace on Knee Adduction Moment and ROM in Patients with medial Knee Osteoarthritis

The knee unloader brace can change loading on knee which may be effective in reducing symptoms and progression of disease in people with knee osteoarthritis. The purpose of this study was to evaluate the effect of a new knee brace during walking in a patient with medial compartment knee osteoarthritis. Two brace types were used: new brace and conventional brace. A pneumatic cuff of novel brace was fitted in the bottom of the medical slipper that were connected to the cuff section of the knee through the tube. After the knee brace is deployed, its force can vary in different stages of the gait. During the heel strike, the weight of the cuff is compressed on the floor, causing the air to flow inside it and entering the volume of air into the knee pad. The results of using this pneumatic knee brace compared with conventional knee braces on a patient showed that in both cases, the open and closed palatal pump, the adduction moment and ROM was decreased in the stance phase. But the three-point knee pressure, however, was less effective in reducing the adduction moment but also reduced the knee ROM. Using novel brace can eliminate the patient’s need for painful and costly surgery to reduce the symptoms of osteoarthritis.

Medial Unloader Braces and Lateral Heel Wedges Do not Alter Gait Biomechanics in Healthy Young Adults

Context: Orthotic devices such as medial unloader knee braces and lateral heel wedges may limit cartilage loading following trauma or surgical repair. However, little is known regarding their effects on gait biomechanics in young, healthy individuals who are at risk of cartilage injury during physical activity due to greater athletic exposure compared with older adults. Objective: Determine the effect of medial unloader braces and lateral heel wedges on lower-extremity kinematics and kinetics in healthy, young adults. Design: Cross-sectional crossover design. Setting: Laboratory setting. Patients: Healthy, young adults who were recreationally active (30 min/d for 3 d/wk) between 18 and 35 years of age, who were free from orthopedic injury for at least 6 months, and with no history of lower-extremity orthopedic surgery. Interventions: All subjects completed normal over ground walking with a medial unloader brace at 2 different tension settings and a lateral heel wedge for a total of 4 separate walking conditions. Main Outcome Measures: Frontal plane knee angle at heel strike, peak varus angle, peak internal knee valgus moment, and frontal plane angular impulse were compared across conditions. Results: The medial unloader brace at 50% (−2.04° [3.53°]) and 100% (−1.80° [3.63°]) maximum load placed the knee in a significantly more valgus orientation at heel strike compared with the lateral heel wedge condition (−0.05° [2.85°]). However, this difference has minimal clinical relevance. Neither of the orthotic devices altered knee kinematics or kinetics relative to the control condition. Conclusions: Although effective in older adults and individuals with varus knee alignment, medial unloader braces and lateral heel wedges do not influence gait biomechanics in young, healthy individuals.

Unloader Knee Brace Increases Medial Compartment Joint Space During Gait In Knee Osteoarthritis Patients

Objectives: Clinical outcome measures suggest the unloader brace provides small-to-moderate improvements in pain and function in varus knee osteoarthritis (OA) patients. However, controversy still exists as to whether the brace has the real effect of increasing tibiofemoral joint space in the medial compartment during functional activity. As a limitation, the previous studies did not report ground reaction forces (GRF) with and without the brace, which could be a confounding factor affecting joint space. Therefore, the purpose of the present study was to investigate the effect of an unloader brace on dynamic joint space in medial compartment in OA patients while simultaneously recording GRF during gait. The hypotheses were (1) dynamic joint space in the medial compartment would be greater with the unloader brace than without the brace during gait, and (2) GRF during gait would be smaller with the brace than without the brace. Methods: Ten varus knee OA patients were enrolled (Age: 52±8 years). After minimum 2-week daily use of the unloader brace, subjects walked (1.0 m/s) on an instrumented treadmill while biplane radiographs of the OA knees were acquired at 100 Hz. Tibiofemoral motion was determined from the biplane radiographs from initial contact to terminal stance phase (gait cycle: 0-40%) using a previously validated model-based tracking process. Dynamic joint space measurement in the medial compartment was performed using previously reported method. Briefly, the medial tibial plateau was divided into 9 sub-regions (Figure 1A) and the average minimum distance between femur and tibia subchondral bone was calculated in each region. The region with the smallest joint space over the three walking trials was selected for the analysis. GRF during gait were collected at 1000 Hz and normalized by each subject’s body weight. Output parameters were averaged over 10% intervals of the gait cycle. Two-way repeated measures ANOVA (gait cycle x brace condition) was used to explore differences in medial compartment dynamic joint space and GRF between the 2 conditions (unbraced and braced). Post-hoc paired t-tests identified the differences between the 2 conditions during the same gait cycle period. Significance level was set as P < 0.05. A subjective questionnaire for the brace usage was collected at the time of the test. Results: The dynamic joint space in the medial compartment was significantly greater with the unloader brace than without the brace during gait ( P = 0.004) (Table 1, Figure 1B). The average difference between the 2 conditions was 0.27 mm (95% confidential interval: 0.12-0.43). No significant difference was observed in terms of GRF between unbraced and braced conditions. The questionnaire showed participants felt reduced pain (4.1±0.7 out of 5 scale) and were comfortable (3.8±0.8 out of 5) when wearing the brace. Conclusion: The unloader knee brace induced a small but significant increase in medial dynamic joint space during gait. Furthermore, no differences in GRF during gait were found between unbraced and braced conditions, indicating that the increase of medial joint space with bracing was not due to decreased limb-loading during gait, but instead due to the brace use itself. These results suggest that the OA unloader brace may reduce medial compartment joint loading during dynamic loading activities. [Figure: see text][Table: see text]