Side to side kinematic gait differences within patients and spatiotemporal and kinematic gait differences between patients with severe knee osteoarthritis and controls measured with inertial sensors.

BACKGROUND: Kinematic changes associated with knee osteoarthritis (OA) have been traditionally measured with camera-based gait analysis. Lately, inertial sensors have become popular for gait analysis with the advantage of being less time consuming and not requiring a dedicated laboratory. RESEARCH QUESTION: Do spatiotemporal and discrete kinematic gait parameters measured with the inertial sensor system RehaGait® differ between the affected and unaffected side in patients with unilateral knee OA and between patients with severe knee OA and asymptomatic control subjects? Do these differences have a similar magnitude as those reported in the literature? METHODS: Twenty-two patients with unilateral knee OA scheduled for total knee replacement and 46 age matched control subjects were included in this study. Spatiotemporal parameters and sagittal kinematics at the hip, knee, and ankle joint were measured using the RehaGait® system while walking at a self-selected speed for a distance of 20 m and compared between groups. RESULTS: Patients with knee OA had slower walking speed, longer stride duration, shorter stride length and lower cadence (P < 0.001). Peak knee flexion during stance and swing was lower in the affected than the unaffected leg (-4.8° and -6.1°; P < 0.01). Peak knee flexion during stance and swing (-5.2° and -8.8°; P < 0.01) and knee range of motion during loading response and swing (-3.6° and -4.4°; P < 0.01) were lower than in the control group. SIGNIFICANCE: These side to side differences within patients and differences between patients with knee OA and control subjects agree with known gait alterations measured with camera-based systems. The RehaGait® inertial sensor system can detect gait alterations in patients with knee OA and is suitable for gait analysis in a clinical environment.

Kinematic changes in patients with severe knee osteoarthritis are a result of reduced walking speed rather than disease severity.

BACKGROUND: Kinematic changes in patients with knee osteoarthritis (OA) have been extensively studied. Concerns have been raised whether the measured spatiotemporal and kinematic alterations are associated with disease progression or merely a result of reduced walking speed. RESEARCH QUESTION: The purpose of this study was to investigate the effect of walking speed on kinematic parameters in patients with knee OA using statistical parametric mapping (SPM). METHODS: Twenty-three patients with unilateral knee OA scheduled for a total knee replacement and 28 age matched control subjects were included in this study. Spatiotemporal parameters and sagittal plane kinematics were measured in the hip, knee, and ankle using the inertial sensors system RehaGait® while walking at a self-selected normal (patients and controls) and slow walking speed (controls) for a distance of 20 m. Gait parameters were compared between groups for self-selected walking speed and for matched walking speed using SPM with independent sample t tests. RESULTS: At self-selected walking speed, patients had significantly lower knee flexion during stance (maximum difference, -6.8°) and during swing (-11.0°), as well as higher ankle dorsiflexion during stance phase (+12.5°) and lower peak hip extension at the end of stance compared to controls (+4.2°). At matched speed, there were no significant differences in joint kinematics between groups. SIGNIFICANCE: Differences in sagittal plane gait kinematics between patients with knee OA and asymptomatic controls appear to be mainly a result of reduced walking speed. These results emphasize the importance of considering walking speed in research on gait kinematics in patients with knee OA and in clinical trials using gait parameters as outcome measures.

Clinical and Biomechanical Outcomes of One-Stage Treatment of a Simultaneous Ipsilateral Patellar Tendon and ACL Tear Combined with a Tibial Plateau Fracture: A Case Study.

Simultaneous ipsilateral patellar tendon (PT) and anterior cruciate ligament (ACL) tear is a rare injury. Associated meniscal and ligamentous injuries are common but frequently initially missed. In contrast, to date, there is no report of associated fractures. We report on a 40-year-old female Caucasian patient presenting with a ski injury resulting in simultaneous ipsilateral patellar tendon and ACL tear combined with a tibia plateau fracture and a medial and lateral meniscus lesion. ORIF of the tibia as well as one-stage primary reconstruction of the PT and ACL and suturing of the menisci was conducted. The final follow-up was 2 years postoperatively. Lower extremity kinematic, kinetic, and muscle activity measurements were conducted. Although the clinical result was excellent, altered joint kinematics went along with large side-to-side difference in hip and knee joint moments during midstance and terminal stance. During weight acceptance, vastus medialis and hamstring muscles showed greater relative activity in the injured than the uninjured side. This case demonstrates the possibility of excellent early and midterm results with a one-stage approach and suitable rehabilitation scheme. Biomechanical measurements could further help evaluate the outcome of the treatments and implications for the development of potential secondary damage.

Total Knee Arthroplasty in Severe Valgus Osteoarthritis Excellent Early Results in a 90-Year-Old Patient with a Valgus Deformity of 47°.

Grade III valgus deformity (tibiofemoral alignment > 20°) is present in only 0.5% of patients receiving total knee arthroplasty. Furthermore, cases with a valgus deformity exceeding 40° are even rarer. Since they mostly affect elderly, polymorbid patients, successful outcome means a great challenge. We report on a case of a 90-year-old patient with a valgus deformity of 47°. The patient was preoperatively restricted to a wheel chair, unable to walk, and only able to stand for a few seconds. The maximal knee flexion was 100°, and there was an extension deficit of 15°. The WOMAC score was 91; the EQ-5D-5L Index was 0.048. She was treated with a constrained hinged prosthesis. Postoperatively, the axis was 6° valgus. After 3 months of rehabilitation, she was independent using a wheeled walker. The maximal flexion of the knee was 110° and there was no extension deficit. The WOMAC score was 45; the EQ-5D-5L Index was 0.813. This case demonstrates the possibility of a satisfactory result and an improvement in quality of life and mobility with a plausible timetable and with reasonable use of resources even in advanced age and severe valgus deformity.