Arthroscopic management of meniscal injuries.

The use of the arthroscope in the diagnosis, classification, and management of meniscal disorders is the most common use of arthroscopic surgery in the knee. There are numerous recent advances in technology and technique that now permit improved diagnosis and treatment of meniscal disorders by arthroscopy. The management of meniscal disorders involves the diagnostic identification of the type of meniscal lesion by examination, imaging studies, and arthroscopy. Identification of the lesion, in turn, would lead to a decision as to whether removal or reattachment of the torn portion of meniscus should be undertaken. This is an important decision to reach based on the anatomy of the meniscal tear, because preservation of the menisci is important in maintaining stability and in guarding against articular cartilage degeneration of the knee joint. The treatment of meniscal disorders no longer requires hospitalization or prolonged recovery. The future holds promise for office arthroscopy, advances in meniscal repair technique, and meniscal transplantation.

Human and bovine articular cartilage loading measured with a new resistive sensor: effects of protease degradation and osteoarthritis.

This report describes the use of a new micro-thin resistive-based sensor to measure dynamic vertical loading of normal and osteoarthritic (OA) human knee cartilage repetitively under conditions of simulated knee joint loading. Articular cartilage discs were cultured in 3 DMEM +/- IL-1, lipopolysacharide (LPS) and trypsin over 7 days. Loading force, force distribution and peak pressure were evaluated. The sensor detected early stiffness and dynamic loading changes due to IL-1, LPS and trypsin treatment, and differences between normal and early OA human cartilages showing decreased cartilage stiffness due to enzyme treatment and osteoarthritis.

The role of alpha-1-protease inhibitor (A1PI) in the inhibition of protease activity in human knee osteoarthritis.

Alpha-1-protease inhibitor (A1PI) is the most abundant serum protease inhibitor, exhibiting inhibition of proteases known to act in osteoarthritis (OA) and rheumatoid arthritis. We have previously purified and sequenced A1PI synthesized by human articular cartilage and demonstrated in vitro protection from IL-1-induced proteoglycan (PG) degradation at a concentration of 1 mg/ml. In this study, the chondroprotective role of A1PI and possible inhibition of protease activity in OA, IL-1 and LPS-induced and aged normal human knee articular cartilage was investigated by immunohistochemical and in vitro methods. A variable low response to PG-degradation induction and to added A1PI protection of aged normal and OA cartilages was noted, while there was decreased constituative A1PI noted in OA cartilages as compared to normal.

Arthroscopic management of disorders of the knee.

Arthroscopy and arthroscopic surgery have gained tremendous popularity within the past several years with both physicians and the general public. Arthroscopic surgery is a dramatic aid in reducing soft tissue injury, rehabilitation time, and the costs associated with surgery when applied to the knee or other large joints of the body. Although this technique is in widespread use for many acute and sports injuries, the arthroscope and developing arthroscopic surgical techniques have significant advantages in the diagnosis and treatment of common inflammatory disorders, rheumatoid arthritis, osteoarthritis, joint synovectomy, septic arthritis, and osteochondritis dissecans. The popularity of arthroscopic management of disorders of the knee and other major joints is well deserved, as these procedures are increasingly successful and hold promise for future major advances in the treatment of joint disease.

Polydactyly of the foot in adults: literature review and unusual case presentation with diagnostic and treatment recommendations.

The authors present an unusual case of polydactyly of the foot in an otherwise healthy adult male. The modern literature describing polydactyly of the foot is reviewed, as well as a review and critique of various classification schemes for foot polydactyly deformities. The authors applied the classification criteria of Blauth and Olason to an atypical case and to other varied, yet typical, presentations of polydactyly of the foot in adults. Nonsurgical and surgical treatment options are reviewed, and a rational treatment plan is proposed based upon use of the classification scheme. They then apply the management plan for symptomatic polydactyly of the foot to the unusual case, and make recommendations for surgical management of this deformity.

Septic bursitis of the foot: diagnosis, management and end-result.

Septic bursitis of the foot is a disorder infrequently reported in the medical literature. This infrequent reporting may represent a true low incidence of occurrence or may be a reflection of failure to recognize and diagnose this condition. This paper retrospectively reviews the presentation, clinical course, and outcome of patients presenting with septic bursitis of the foot. The authors have reviewed those features of this disorder that may aid the clinician in diagnosis and management of this infrequent, but disabling entity. They describe a brief case history of 10 patients with septic bursitis of the foot, provide radiographic and microbacterial evaluation, and give an outcome determination. They make recommendations for diagnosis and treatment based upon this review of patients and review of the literature.

The presence and possible functions of the matrix metalloproteinase collagenase activator protein in developing enamel matrix.

The developing enamel matrix contains mostly amelogenins, which are hydrophobic proline-rich proteins. During amelogenesis, the amelogenins are presumably hydrolysed and removed from the enamel. Recently a number of metalloproteinases that may be important in amelogenesis have been identified in zymograms of the developing enamel matrix. In the present study an antibody specific for the matrix metalloproteinase collagenase activator protein (CAP) was characterized and used to identify this metalloproteinase in enamel. Immunoblotting showed that the CAP proteinase was present in the enamel matrix. Immunohistochemistry confirmed that the proteinase is localized in the enamel matrix, most specifically along the dentino-enamel junction. Purified CAP was found to hydrolyse amelogenin protein. Possible functions of the proteinase in the enamel matrix are discussed.

Chronic exercise-induced compartment pressure elevation measured with a miniaturized fluid pressure monitor. A laboratory and clinical study.

Increased pressure within an osteofascial compartment may produce a compartment syndrome, one of the principal causes of circulatory compromise in acute traumatic and chronic exercise-induced elevated compartment pressure. Acute and chronic diagnostic quantitation of compartment pressures are a valuable adjunct to clinical diagnosis, particularly when used to evaluate the athlete with exercise-induced pain. This study evaluated a prototype hand-held, digital, fluid pressure monitor used for the measurement of compartment pressure in the exercising athlete. A laboratory water and mercury manometer study, in which 50 paired, single-blind measurements were taken, revealed that the digital monitor was accurate to +/- 0.8 mm Hg (SD) of actual pressure with no individual reading more than 1 mm Hg from the actual pressure when compared directly with a mercury and a water column. Laboratory study of bovine muscle placed within a pressure chamber revealed that the digital monitor, when assembled in the same manner as used for clinical measurement, was accurate to +/- 0.9 mm Hg. The needle manometer technique was also found to be accurate to +/- 3 mm Hg from actual pressure. Twenty-one paired measurements of the anterolateral and posterior compartments of the hindlimbs of eight anesthetized New Zealand White rabbits by both the needle manometer and digital monitor methods by two examiners demonstrated the digital monitor to be reproducible to +/- 1.0 mm Hg [Coefficient of variation (CV) less than 7%] and needle manometer method to +/- 3.4 mm Hg (CV less than 16%) with r = 0.94.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulation of cartilage remodeling by IL-1: evidence for autocrine synthesis of IL-1 by chondrocytes.

Evidence is presented for the synthesis of Interleukin-1 (IL-1) by joint synovial tissue and chondrocytes. Purified preparations of mouse and human recombinant forms of this factor stimulate the synthesis of a secretory protease by cartilage. The IL-1 stimulated chondrocyte protease is capable of converting latent collagenase to its active form. Other proteases such as trypsin and the mercurial aminophenyl mercuric acetate will not activate collagenase in the absence of this protease. Evidence is presented showing that chondrocytes synthesize IL-1 suggesting autocrine control of cartilage matrix turnover.

The late effect of subtotal thyroidectomy and radioactive iodine therapy on calcitonin secretion and bone mineral density in women treated for Graves' disease.

This study was designed to evaluate the effect of subtotal thyroidectomy and/or radioactive iodine therapy on plasma immunocalcitonin (iCT) levels and bone densities in patients treated for Graves' disease. Forty-eight women whose ages ranged from 29 to 79 years (mean, 55 years) were evaluated. All were at least 10 years beyond treatment. Fourteen patients had undergone subtotal thyroidectomy, 22 had received radioactive iodine therapy, and 12 had received both. Serum calcitonin levels were measured with the patient fasting and at 30 minutes and 2 hours after the ingestion of 15 mg of calcium in orange juice. Single photon absorptiometry was used to measure bone mineral density of the middle and distal radius. The mean fasting plasma levels of iCT for patients undergoing subtotal thyroidectomy was 27 +/- 2 mumol/L; women treated with radioactive iodine, 26 +/- 2; women undergoing subtotal thyroidectomy followed by radioactive iodine, 24 +/- 2, and for normal control women, 48.5 +/- 4.7. The mean stimulated iCT level of each of the patient groups was significantly lower than that of the normal controls (p = 0.01). There were no significant differences among the groups. Although there was an increased loss of bone mineral density in postmenopausal patients, with age and race as covariates, the bone densities of the distal radius in women undergoing subtotal thyroidectomy and/or receiving radioactive iodine were not significantly lower than those of normal control subjects (p greater than 0.05). These findings are consistent with other observations that patients treated by thyroidectomy and/or radioactive iodine for Graves' disease have lower basal levels of calcitonin and decreased calcitonin response to a provocative stimulus. Whether this loss of calcitonin reserve is a significant factor in development of postmenopausal osteoporosis remains unanswered.

Mesothelial cysts of the round ligament simulating inguinal hernia. Report of four cases and a review of the literature.

Cysts of the mesothelial investment of the round ligament are rare and occur in women in their late third or fourth decades. They are relatively painless, mobile, may be perceived to be reducible, and should be included in the differential diagnosis of groin masses in women. Differentiation of these cysts from a small indirect inguinal hernia, with which they are frequently associated, is difficult and may be made only at the time of operation. They are likely to be less symptomatic than inguinal hernias. Cysts should not change in size with the Valsalva maneuver, although they may become more conspicuous with coughing. The clinical manifestations of cysts of the round ligament in four patients are described, along with a discussion of their embryologic and pathologic characteristics and a summary of the world literature. An embryologic mechanism of cyst formation is proposed and diagnostic criteria are presented. Symptomatic cysts of the inguinal ligament should be excised and the inguinal canal should be explored for possible associated indirect inguinal hernias. In the absence of symptoms or of a progressive increase in size, surgical removal of a cyst of the round ligament is not mandatory.

In vivo bone mineral analysis throughout skeletal growth in rats: differences due to sex or vitamin D deficiency.

This study reports a new technique for the measurement of bone mineral content (BMC) in live rats. A single photon absorptiometric instrument has been adapted for rapid, reproducible measurement of BMC. Four bone sites were selected for use, based on ease of positioning and reproducibility of measurement; these were as follows: proximal femur, midfemur, proximal seventh caudal vertebra, and midseventh caudal vertebra. Significant increases were detected when BMC was measured at biweekly intervals from weaning to 18 weeks of age in normal male rats. Comparison of body growth and changes in BMC of male and female rats with age showed that body weight gain of female rats slowed earlier than that of male rats whereas BMC increased at similar rates in both sexes. Vitamin D deprivation from day 24 of life resulted in decreased BMC at all four measurement sites compared with such measurements in normal control rats. Differences were detectable after 8 weeks of age and occurred despite the maintenance of serum calcium levels within normal range and only slight reduction in body weights of vitamin D deprived rats. These studies demonstrate that single photon absorptiometry can be used to monitor changes in BMC in live rats on a routine basis without harm to the animals. Changes in BMC such as those due to growth or vitamin D deprivation can easily be quantitated using this technique.

Bone density in women: a modified procedure for measurement of distal radial density.

This is a cross-sectional study of bone densitometry in greater than 700 normal healthy white women ranging in age from 18 to 98 years. A modified procedure for single-photon bone density analysis of the distal radius is described and compared with dual-photon densitometric measurements of the second through fourth lumbar vertebrae. The distal radial site measured was separated from the ulna by 5 mm. This "5 mm" site was characterized according to trabecular and cortical bone content, measurement reproducibility, positioning precision, and the effects of wrist pronation or supination. The radial site demonstrated a bone density loss of less than 0.1%/year for normal women 25-50 years of age, increasing to 0.7%/year after 50 years of age. In contrast to the variability and inconsistency obtained by us and others utilizing the standard "9/10" site, bone loss with age at the new "5 mm" site correlated closely with generalized bone mineral loss of the axial skeleton. We suggest that there is a unique role for single-beam densitometric measurements of the radius, permitting the rapid and relatively inexpensive evaluation of large populations of women without requiring a visit to a medical center. Such a process can select those requiring further evaluation or medical attention.

Bone density in osteopenic women: a modified distal radius density measurement procedure to develop an "at risk" value for use in screening women.

This study measured radial and lumbar spine bone density in postmenopausal white female patients with nontraumatic fractures and their age-matched controls. Bone density measurements were made with a single-beam densitometer. Distal radial bone density measurements were made at the site at which the radius and ulna are separated by 5 mm, which is approximately 5 mm from the distal radioulnar joint. Lumbar spine density was obtained using a dual-beam densitometer. Density at the commonly used "2/3" site near the midradius was also measured. Forty-six crush fracture osteoporotic patients, 35 hip fracture patients, and 20 osteopenic patients referred to the clinic for back pain or excessive bone loss but with no history of nontraumatic fracture were studied. Bone density values at all sites in the patient populations were statistically reduced from control values (p less than 0.01). At a mean age of 62 years, density of the midradius was 12% below the control value. However, both vertebral and distal radial densities ("5 mm" site) were 25% below control values. The spine/distal radius ratio remained constant. It was demonstrated that bone density at the modified distal radial site could be used to predict vertebral density in osteopenic patients. An "at risk" value useful in screening procedures was determined as that distal radius density value greater than or equal to 95% of all values from fracture patients--325 mg/cm2. It is concluded that distal radial density at the new "5 mm" site can be used in conjunction with midradius density as a preliminary test for both generalized and trabecular bone mass loss in women.

Late complications of total hip replacement from bone cement within the pelvis. A review of the literature and a case report involving dyspareunia.

It is not uncommon to observe bone cement in the pelvis on radiographs after total hip replacement, a finding which is generally considered to be benign. This paper reviews some catastrophic late complications from intrapelvic methylmethacrylate. We also describe a case of progressive, unbearable dyspareunia beginning three years after total hip replacement. A possible explanation of the pathophysiology is suggested. Recommendations for prevention, diagnosis, and treatment of these late complications are offered.

Legg-Calvé-Perthes disease in dogs: a comparison to human Legg-Culvé-Perthes disease.

The femoral heads of 12 dogs with naturally occurring Legg-Calvé-Perthes disease were studied by light and electron microscopic techniques. In the early stages of the disease, the bony capital femoral epiphysis was necrotic, but the articular cartilage and growth plate cartilage were not affected. By the early stages of repair, the femoral head had collapsed. the articular cartilage was thickened and furrowed at the sites of collapse, and the chondrocytes appeared more metabolically active. Sites of bone resorption were associated with osteoclasts and macrophages. In some specimens there were areas of necrosis in the metaphysis which interrupted normal enchondral ossification in the growth plate. By the final stages of repair, the epiphysis was almost completely revascularized with the exception of the central proximal segment. In some areas, repair tissue had penetrated into the deeper layers of the articular cartilage. The flattening of the femoral head in Legg-Calvé-Perthes disease appears to be the result of several processes: mechanical collapse, asymmetric growth, and disturbed enchondral ossification at the growth plate.

Binding of human thrombin to cultured human endothelial cells.

Binding of thrombin to monolayer cultures of human umbilical vein endothelium is studied. Binding is measured as inhibition by unlabeled ligand of the binding of 125I-thrombin to the cells. Radioactivity bound to cultures at equilibrium is measured after draining but not washing the cells. To correct for unremoved supernatant, 131I-albumin is included as a second label in the medium. Equilibrium between bound and free thrombin is attained within 1 min, and Scatchard analysis indicates a population of approximately 3 x 10(3) sites/cell with a dissociation constant of 10(-10) M, and a larger population with a dissociation constant greater than 10(-8) M. The two populations of sites are also indicated by a biphasic dissociation of bound label. Thrombin inactivated with diisopropyl fluorophosphate binds to the same receptor, with an affinity similar to that of active thrombin. Binding is unaffected by albumin (an acidic protein) and cytochrome c (a basic protein). Cultures of umbilical cord smooth muscle and fibroblasts bind thrombin at least 100 times more weakly than endothelium, and no binding to erythrocytes or a monolayer culture of mouse neuroblastoma is detected.