Ultrasound measures of muscle thickness may be superior to strength testing in adults with knee osteoarthritis: a cross-sectional study.

BACKGROUND: Evaluation of muscle strength as performed routinely with a dynamometer may be limited by important factors such as pain during muscle contraction. Few studies have compared formal strength testing with ultrasound to measure muscle bulk in adults with knee osteoarthritis (OA). METHODS: We investigated the muscle bulk of lower limb muscles in adults with knee OA using quantitative ultrasound. We analyzed the relationship between patient reported function and the muscle bulk of hip adductors, hip abductors, knee extensors and ankle plantarflexors. We further correlated muscle bulk measures with joint torques calculated with a hand held dynamometer. We hypothesized that ultrasound muscle bulk would have high levels of interrater reliability and correlate more strongly with pain and function than strength measured by a dynamometer. 23 subjects with unilateral symptomatic knee OA completed baseline questionnaires including the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Lower Extremity Activity Scale. Joint torque was measured with a dynamometer and muscle bulk was assessed with ultrasound. RESULTS: Higher ultrasound measured muscle bulk was correlated with less pain in all muscle groups. When comparing muscle bulk and torque measures, ultrasound-measured muscle bulk of the quadriceps was more strongly correlated with measures of pain and function than quadriceps isometric strength measured with a dynamometer. CONCLUSIONS: Ultrasound is a feasible method to assess muscle bulk of lower limb muscles in adults with knee OA, with high levels of interrater reliability, and correlates negatively with patient reported function. Compared with use of a hand held dynamometer to measure muscle function, ultrasound may be a superior modality.

Fundamental Considerations for Ultrasound-Guided Musculoskeletal Interventions.

Ultrasound can be used to guide joint and soft tissue interventions to improve accuracy, efficacy, patient satisfaction, and to minimize complications. This article summarizes the rationale supporting ultrasound-guided injections and explains how to safely and effectively set up and perform these procedures.

Calcaneal quantitative ultrasound compared with hip and femoral neck dual-energy x-ray absorptiometry in people with a spinal cord injury.

OBJECTIVE: To evaluate the sensitivity and specificity of calcaneal quantitative ultrasound (QUS) measurements for identifying osteoporosis determined by dual-energy x-ray absorptiometry (DXA) at the hip in a spinal cord injury (SCI) population. DESIGN: Cross-sectional retrospective review of data collected in the bone health registry of persons with a disability. SETTING: Inpatients and outpatients at a single acute rehabilitation hospital. PARTICIPANTS: A convenience sample of 66 participants, both inpatients and outpatients, with a spinal cord injury. METHODS: Calcaneal T scores were determined by ultrasound, and bone density of the lumbar spine, total hip, and femoral neck were determined by DXA. MAIN OUTCOME MEASUREMENTS: Right and left calcaneal QUS T scores and right and left hip and femoral neck DXA T scores. RESULTS: Right and left hip DXA T scores were strongly associated with corresponding right and left calcaneal QUS T scores (right: r = .72, P < .001; left: r = .70, P < .001). Similar associations were found when we evaluated femoral neck T scores and calcaneal QUS T scores. Receiver operating characteristic analysis for evaluating QUS to identify DXA-defined osteoporosis demonstrated an area under the curve of 0.81 for all participants (acute and chronic injury) and 0.68 for those with a chronic SCI. CONCLUSIONS: A strong association exists between calcaneal QUS T scores and bone density T scores at the hip measured by DXA. QUS may have a place in the screening of people with SCI 1 year or more after their injury to evaluate their bone status.