Use of glucosamine and chondroitin sulfate in the management of osteoarthritis.

The goals of osteoarthritis therapy are to decrease pain and to maintain or improve joint function. The pharmacologic treatment of this condition has included the use of aspirin, acetaminophen, and nonsteroidal anti-inflammatory drugs. More recently, numerous studies have investigated the potential role of chondroprotective agents in repairing articular cartilage and decelerating the degenerative process. The reports of limited clinical experience with two of these agents, glucosamine and chondroitin sulfate, as well as the accompanying publicity in the popular media, have generated controversy. Advocates of these alternative modalities cite reports of progressive and gradual decline of joint pain and tenderness, improved mobility, sustained improvement after drug withdrawal, and a lack of significant toxicity associated with short-term use of these agents. Critics point out that in the great majority of the relevant clinical trials, sample sizes were small and follow-up was short-term.

Reconstruction of the failed femoral component and proximal femoral bone loss in revision hip surgery.

Advances in implant technology and surgical techniques have greatly improved the results of femoral stem revision in total hip arthroplasty. The 10-year results obtained with extensively coated noncemented revision stems parallel those obtained with cemented stems revised by using contemporary techniques. Proximal femoral bone loss is an important consideration when planning and performing revision arthroplasty. Proximal femoral bone defects can be managed with either metal or bone. Insignificant defects can be reconstructed by using primary hip arthroplasty techniques. Proximal femoral replacement prostheses are best restricted to sedentary elderly patients. Cortical strut grafts can be used reliably to reconstruct noncircumferential segmental defects. Calcar allografts are associated with unacceptably high rates of resorption. Proximal femoral allografts with either noncemented or cemented long-stem prostheses have the potential advantage of biologic soft-tissue attachment and restoration of bone stock. Impaction allografting with cement is indicated for cavitary defects and may also restore bone stock.

The genetic basis of the osteochondrodysplasias.

The osteochondrodysplasias are a heterogeneous group of disorders characterized by abnormal growth and remodeling of cartilage and bone, affecting from 2 to 4.7 per 10,000 individuals. Most osteochondrodysplasias are heritable and many have elaborate patterns of genetic transmission. Affected individuals generally require management by multidisciplinary teams of specialists. In this review, we divide the osteochondrodysplasias into groups based on their genetic relationships, including mutations in various types of collagen, fibroblast growth factor, cartilage oligomeric matrix protein, parathyroid hormone receptor, the diastrophic dysplasia sulfate transporter, enzymes such as steroid sulfatases, transcription factor SOX9, and a cysteine proteinase, cathepsin K. We describe the major osteochondrodysplasias, define their causes and clinical manifestations, and provide the orthopaedic surgeon with an understanding of the underlying molecular defects as well as the anatomical aspects of these disorders.

Iatrogenic spondylolysis leading to contralateral pedicular stress fracture and unstable spondylolisthesis: a case report.

STUDY DESIGN: A case report of iatrogenic spondylolysis as a complication of microdiscectomy leading to contralateral pedicular stress fracture and unstable spondylolisthesis. OBJECTIVE: To improve understanding of this condition by presenting a case history and roentgenographic findings of a patient that differ from those already reported and to propose an effective method of surgical management. METHODS: A 67-year-old woman with no history of spondylolysis or spondylolisthesis underwent an L4-L5 microdiscectomy for a left herniated nucleus pulposus 1 year before the current consultation. For the preceding 8 months, she had been experiencing low back and bilateral leg pain. Imaging studies revealed a left L4 spondylolytic defect and a right L4 pedicular stress fracture with an unstable Grade I spondylolisthesis. RESULTS: The patient was treated with posterior spinal fusion, which resulted in complete resolution of her clinical and neurologic symptoms. CONCLUSIONS: Iatrogenic spondylolysis after microdiscectomy is an uncommon entity. However, it can lead to contralateral pedicular stress fracture and spondylolisthesis, and thus can be a source of persistent back pain after disc surgery. Surgeons caring for these patients should be aware of this potential complication.

Viscosupplementation for osteoarthritis.

Viscosupplementation therapy can restore the elastic and viscous properties of synovial fluid and thus recreate the intra-articular joint homeostasis that is disrupted in the degenerative joint. Hyaluronan (hyaluronic acid) products have been developed and used for viscosupplementation therapy in osteoarthritis. Viscosupplementation treatments using these products are well tolerated. Because viscosupplementation therapy is based on the concept of replenishing a normal physiological component of synovial fluid and cartilaginous tissue, exogenous administration of hyaluronic acid has the potential to have few side effects or local or systemic reactions. Viscosupplementation represents an alternative treatment for patients with osteoarthritis in which oral medications and/or surgery are not options or are ineffective.

Vertical shear fractures of the femoral neck. A biomechanical study.

A biomechanical cadaver study was performed to compare the strength and stability of three cannulated cancellous lag screws with a sliding hip screw for fixation of a vertically oriented fracture of the femoral neck (Pauwels Type III). Using eight matched pairs of human cadaveric femurs, vertically oriented femoral neck osteotomies were created, reduced, and randomized to one of the two fixation methods. The constructs were tested with incremental axial loading from 100 N to 1200 N and cyclical loading at 1000 N for 10,000 cycles; fracture displacements and ultimate load to failure were determined. The specimens stabilized using a sliding hip screw showed less inferior femoral head displacement, less shearing displacement at the osteotomy site, and a much greater load to failure than did those stabilized with multiple cancellous lag screws. These results support the use of a sliding hip screw for treatment of vertically oriented fractures of the femoral neck.

The effects of nutritional status on outcome after hip fracture.

OBJECTIVE: To determine the effect of nutrition on patient outcome after hip fracture. STUDY DESIGN: Retrospective review of prospectively collected data. METHODS: Four hundred ninety hip fracture patients had albumin and total lymphocyte count levels determined at the time of admission and constituted the study population. These variables were examined as predictors for outcomes, including: in-hospital mortality, postoperative complications, hospital length of stay, hospital discharge status, one-year mortality rate, ambulatory ability, and independence in basic and instrumental activities of daily living twelve months after surgery. RESULTS: Eighty-seven patients (18 percent) were found to be malnourished on hospital admission based on a preoperative albumin level of < 3.5 grams/deciliter, and 280 patients (57 percent) based on a total lymphocyte count of < 1,500 cells/milliliter. An albumin level of < 3.5 grams/deciliter was predictive for increased length of stay (p = 0.03) and for in-hospital mortality (p = 0.03). A total lymphocyte count < 1,500 cells/milliliter was predictive for one-year mortality (p < 0.01). Patients with abnormal albumin and total lymphocyte count were 2.9 times more likely to have a length of stay greater than two weeks (p = 0.03), 3.9 times more likely to die within one year after surgery (p = 0.02), and 4.6 times less likely to recover their prefracture level of independence in basic activities of daily living (p < 0.01). Neither parameter was predictive for patients developing a postoperative complication, hospital discharge status (home versus nursing home), recovery of prefracture ambulatory ability, or independence in instrumental activities of daily living at twelve-month follow-up. CONCLUSION: Patients at risk for poor outcomes after hip fracture can be identified using relatively inexpensive laboratory tests such as albumin and total lymphocyte count.

The self-compressing tibial intramedullary nail.

Laboratory evaluation of a self-compressing tibial nail demonstrated that significant, initial compression of a simulated fracture or nonunion can be obtained and controlled. However, when this nail was tested in cyclic loading, loss of its initial static compression occurred.