Quantitative Measurement of Muscle Atrophy and Fat Infiltration of the Supraspinatus Muscle Using Ultrasonography After Arthroscopic Rotator Cuff Repair

OBJECTIVE: To investigate the utility of ultrasonography to objectively examine morphological changes (i.e., muscle atrophy and fatty infiltration) of the supraspinatus muscle. METHODS: Thirty-four patients were prospectively enrolled in this study. The degrees of muscle atrophy and fat infiltration were measured using ultrasonography 3–4 months after arthroscopic supraspinatus tendon repair. Shoulder function (i.e., shoulder active range of motion, visual analogue scale, and constant score) was examined. Using the symmetricity of the muscles in the human body, the degrees of morphological changes of the supraspinatus muscle were quantitatively measured. The associations between the morphological changes of the supraspinatus muscle and shoulder function were identified. RESULTS: There were statistically significant differences in the cross-sectional area (CSA) and echogenicity between the surgery and non-surgery sides (p < 0.001). The CSA ratio, which represents the degree of muscle atrophy, was associated with shoulder forward flexion, external rotation, and constant score; however, the echogenicity ratio, which represents the degree of fat infiltration, was not associated with shoulder function after surgery. CONCLUSION: This study demonstrated that shoulder function could be predicted by evaluating the morphological changes of the supraspinatus muscle using ultrasonography and that objective evaluation is possible through quantitative measurement using the symmetricity of the human body.

Reference Value for Infrapatellar Branch of Saphenous Nerve Conduction Study: Cadaveric and Clinical Study

OBJECTIVE: To determine the optimal stimulation and recording site for infrapatellar branch of saphenous nerve (IPBSN) conduction studies by a cadaveric study, and to confirm that obtained location is practically applicable to healthy adults. METHODS: Twelve lower limbs from six cadavers were studied. We defined the optimal stimulation site as the point IPBSN exits the sartorius muscle and the distance or ratio were measured on the X- and Y-axis based on the line connecting the medial and lateral poles of the patella. We defined the optimal recording site as the point where the terminal branch met the line connecting inferior pole of patella and tibial tuberosity, and measured the distance from the inferior pole. Also, nerve conduction studies were performed with obtained location in healthy adults. RESULTS: In optimal stimulation site, the mean value of X-coordinate was 55.50±6.10 mm, and the ratio of the Y-coordinate to the thigh length was 25.53%±5.40%. The optimal recording site was located 15.92±1.83 mm below the inferior pole of patella. In our sensory nerve conduction studies through this location, mean peak latency was 4.11±0.30 ms and mean amplitude was 4.16±1.49 µV. CONCLUSION: The optimal stimulation site was located 5.0–6.0 cm medial to medial pole of the patella and 25% of thigh length proximal to the X-axis. The optimal recording site was located 1.5–2.0 cm below inferior pole of patella. We have also confirmed that this location is clinically applicable.

Musculoskeletal Problems in Lower Extremity after Stroke

Stroke is a leading cause of disability in the elderly. Among complications of stroke, musculoskeletal problems are common, thereby causing improper gait biomechanics, development of pain, and limitation in performing activities of daily living. Post-stroke hip fractures and greater trochanteric pain syndrome are common complication near hip joint. Knee osteoarthritis can be accelerated by altered biomechanics of post-stroke period, that is associated with ambulation levels. Stiff knee gait and genu recurvatum can be developed after stroke and usually contribute to abnormal gait patterns, due to weakness or spasticity of various muscles, and they need to control or compensate affected muscle activities. In case of ankle and foot problems, foot varus deformity is caused by imbalance between muscles that control ankle movement, while claw toes and the persistent extension of the great toe are mainly due to overactivity of muscles that moves toes, and mainstay of treatment is to control inappropriate activities of affected muscles. It is important to make the exact therapeutic decision and establish the rehabilitation plan through the early evaluation of lower extremity musculoskeletal problems that affect the mobility and ambulation.