A better "sky hook" for hand elevation.

Exercise-induced spin-spin relaxation time (T2) shifts in magnetic resonance (MR) images were used to test the hypothesis that more muscle would be used to perform a given submaximal task after 5 wk of unweighting. Before and after unilateral lower limb suspension (ULLS), 7 subjects performed 5 sets of 10 unilateral concentric actions with the quadriceps femoris muscle group (QF) at each of 4 loads: 25, 40, 55, and 70% of maximum. T2-weighted MR images of the thigh were collected at rest and after each relative load. ULLS elicited a 20% decrease in strength of the left unweighted QF and a 14% decrease in average cross-sectional area (CSA) with no changes in the right weight-bearing QF. Average CSA of the left or right QF showing exercise-induced T2 shift increased as a function of exercise intensity both before and after ULLS. On average, 12 +/- 1, 15 +/- 2, 18 +/- 2, and 22 +/- 1 cm2 of either QF showed elevated T2 for the 25, 40, 55, and 70% loads, respectively, before ULLS. Average CSA of the left but not the right QF, showing elevated T2 after ULLS, was increased to 16 +/- 2, 23 +/- 3, 31 +/- 7, and 39 +/- 5 cm2, respectively. The results indicated that unweighting increased exercise-induced T2 shift in MR images, presumably due to greater muscle mass involvement in exercise after than before unweighting, suggesting a change in motor control.

Casts, Surgical↗

PubMed1995

Congenital dislocation of the hip in boys.

Fifty-five boys with seventy-eight congenitally dislocated hips were treated between 1965 and 1990. The patients were divided into three groups according to the initial treatment. Group I included thirty hips (twenty-two boys) that had been treated initially with a Pavlik harness. Two hips (7 per cent) had a successful outcome, and twenty-eight (93 per cent) needed additional methods of treatment. Group II included forty-two hips (twenty-nine boys) that had been treated initially with closed reduction and immobilization in a hip-spica cast. After the closed reduction, twenty-nine hips (69 per cent) were considered stable, although fifteen (52 per cent) of them needed a secondary procedure because of residual subluxation or persistent acetabular dysplasia. Thirteen hips (31 per cent) were considered unstable after the closed reduction and subsequently had an open reduction. Group III included six hips (four boys) that had been treated initially with open reduction. Two of these hips redislocated after the open reduction, and they were reduced with an additional open reduction. A pelvic osteotomy was later performed to treat persistent acetabular dysplasia in these two hips. Two hips that had been treated with an open reduction and concomitant pelvic and femoral procedures did not need additional treatment. This study demonstrates that boys who have congenital dislocation of the hip do not always respond well to treatment and constitute a high-risk group.

Casts, Surgical↗