Hip pain in the young adult: diagnosis and treatment of disorders of the acetabular labrum and acetabular dysplasia.

Hip pain in the young adult patient (ages, 17-35 years) is a diagnostic and therapeutic challenge for the orthopedic surgeon. The diagnostic and treatment algorithm for many causes of hip pain in the young adult-such as tumors and tumoral conditions, rheumatoid and degenerative arthritis, osseous necrosis, and the sequelae of congenital problems such as slipped capital femoral epiphysis and Legg-Calve Perthes--are well described and established. However, the diagnosis and treatment algorithm for disease processes, such as disorders of the acetabular labrum and dysplasia of the hip, are less clear. Advances in diagnostic radiology, particularly magnetic resonance arthrography, and advances in therapy, including the successful use of the Bernese periacetabular osteotomy and hip arthroscopy, have allowed for both timely diagnosis and appropriate treatment of these sources of hip pain in the young adult. The purpose of this review is to outline the diagnostic and treatment decision-making protocol for young adult patients with hip pain, and specifically to discuss the treatment of acetabular labral tears and dysplasia of the hip.

Relationship of femoral head and acetabular size to the prevalence of dislocation.

Two clinical studies, one prospective randomized and one retrospective, were performed to evaluate the relationship of femoral head size and acetabular component outer diameter to the prevalence of dislocation of the modular total hip replacement. Between October 1995 and April 1996, 31 primary total hip arthroplasties in 30 patients were randomized to a femoral head diameter of 22 mm or 28 mm, for two groups of acetabular components of outer diameters of 56 mm or larger and 54 mm or smaller. Head size (22 mm) and acetabular component outer diameter (> or = 56 mm) were found to increase the risk of dislocation. From December 1984 to January 1994, 308 primary total hip arthroplasties were performed through a posterior approach by one surgeon using a modular 28 mm femoral head and one type of uncemented acetabular component. The rate of dislocation for acetabular components with an outer diameter of 62 mm or larger was increased significantly (five of 36 hips, 14%) compared with those with an outer diameter of 60 mm or smaller (11 of 272 hips, 4%).

Results and complications of total hip arthroplasties in patients with sickle-cell hemoglobinopathies. Role of cementless components.

The complications and results of 16 primary and revision total hip arthroplasties in patients with sickle-cell hemoglobinopathies were evaluated. One patient died from renal failure at 1 year, leaving 15 hips in 10 patients for review at a mean follow-up period of 6 years (range, 2-12 years). There were 7 cementless primary total hip arthroplasties and 8 revision arthroplasties, 6 of which were uncemented. Patients were evaluated clinically using a standard hip rating system and radiographically using accepted criteria. There were no early or late deep infections; however, 7 of 8 primary arthroplasties and 5 of 8 revisions had one or more early complications. No cementless component demonstrated loosening; however, there was asymptomatic polyethylene wear in 2 primary arthroplasties, treated with grafting and liner exchange, and femoral osteolysis was present in 4 of 13 cementless arthroplasties, one of which was revised to permit extensive grafting. Of the original 15 arthroplasties performed by the senior author, 5 required some type of reoperation during the study. At most recent follow-up evaluation, no component in the study was radiographically loose. In the hips that did not require reoperation, the overall results were excellent in 6 hips, good in 3, and poor in 1 hip. Of the 5 hips requiring reoperation, the results were excellent in 3 hips, good in 1, and fair in 1 hip at most recent follow-up evaluation. Cementless components should be considered for all primary and revision arthroplasties in patients with sickle-cell hemoglobinopathies, but early complications are frequent and a high incidence of polyethylene wear and osteolysis requiring reoperation may be expected.

Insulin inhibits beta-adrenergic responses in fetal rabbit lung in explant culture.

Infants of diabetic mothers are at increased risk of a number of problems at birth. Among these problems are increased risks of respiratory distress syndrome and transient tachypnea of the newborn. Because surfactant synthesis, surfactant secretion, and lung fluid resorption are all mediated in part by beta-adrenergic responses, we asked if excess insulin interferes with the beta-adrenergic response cascade in fetal lung. Lungs from fetal rabbits (26 day) were grown in explant culture in hormone-supplemented culture medium. The explants were harvested after 48 h exposure to hormones and processed for determination of beta-adrenergic receptor concentration, guanine nucleotide regulatory proteins (Gs, Gi), beta-agonist stimulated adenosine 3',5'-cyclic monophosphate (cAMP) generation, cAMP-dependent phosphodiesterase activity, and choline incorporation into phosphatidylcholine. Although insulin did not change the concentration of beta-adrenergic receptors, it decreased the ability of isoproterenol to stimulate cAMP generation. Increase in stimulation over basal was similar in explants treated with dexamethasone and dexamethasone plus insulin, but absolute levels of isoproterenol-stimulated cAMP were less in the explants treated with dexamethasone plus insulin. We speculate that insulin inhibition of cAMP generation may be important in the pathogenesis of the respiratory problems of infants of diabetic mothers.