OKOJ, Volume 9, No. 4

Wear and osteolysis initiated by polyethyelene wear debris is a major limitation of the long-term success of total knee arthroplasty. Osteolysis generally occurs around the tibial baseplates and femoral and patellar components of total knee replacements. Many factors influence the amount of wear and osteolysis that occurs over time, including patient, implant, and surgical factors.Multiple factors related to the manufacturing of the polyethylene implant influence the extent of wear; therefore, surgeons should be cautious in considering enhanced polyethylenes pending results of further investigations. Ultra-high–molecular-weight polyethylene (UHMWPE) has long been the conventional polymer for use in total knee replacement. Cross-linked UHMWPEs have in fact replaced conventional UHMWPE (gamma sterilized in air or an inert gas) for total hip replacements in the United States. In total knee replacements, however, the reduced fatigue strength of UHMWPE with cross-linking remains a concern. Current material research has focused on improving the fatigue-resistant properties of UHMWPE without the loss of resistance to wear and oxidation.

The anterior approach to total hip arthroplasty is nearly as old as the procedure itself.There has been a renewed interest in the approach, particularly as it has been performed using a specially designed fracture table. Excellent clinical outcomes have been reported in numerous short-term and medium-term studies. There remains, however, concern that the steep learning curve and universal complications such as fracture and soft-tissue trauma might potentially outweigh the benefits of enhanced stability and quicker return to function associated with this approach. Long-term data demonstrating functional superiority of the anterior approach to alternate approaches are not yet available.

Glenohumeral arthritis in the young, active patient represents a clinical challenge for the treating physician because of these patients’ higher functional demands and their need to maintain a functional shoulder for many additional decades of life. Nonsurgical treatment followed by joint-sparing or joint-preserving surgical procedures should be pursued whenever possible. Such surgical treatment options include débridement, capsular release, microfracture, autologous chondrocyte implantation, and osteochondral allograft techniques. When joint replacement is needed, partial resurfacing or bone-preserving procedures may offer effective solutions. When complete humeral and/or glenoid replacement is required, careful decisions about expectations and functional requirements are needed, and alternative bearing surfaces can be considered.

Compartment syndrome is a limb-threatening condition that results from increased pressures within a confined myofascial compartment that impair effective tissue perfusion. Common etiologies of compartment syndrome include trauma, reperfusion injury, and positional complications. The outcomes of the untreated compartment syndrome are ischemia and tissue necrosis secondary to failure of the microcirculatory system. The diagnosis of compartment syndrome is typically made by clinical findings in the awake and cooperative patient, and requires emergent fasciotomy to restore the circulatory status of the involved extremity once the diagnosis is suspected. Direct intracompartmental pressure measurements are useful for the obtunded or noncooperative patient, but are not necessary to confirm the diagnosis if clinical suspicion is high. As one of the true orthopedic emergencies, rapid diagnosis and treatment are essential to achieve a satisfactory outcome for this potentially devastating condition. This article will discuss the diagnosis and treatment of compartment syndromes in general, as well as specific management strategies for treating compartment syndromes in the forearm and lower extremity.