JAAOS

JAAOS, Volume 2, No. 4


Isokinetic Muscle Testing: Is It Clinically Useful?

The use of computer-driven muscle-testing devices has become increasingly popular during the past two decades. This expensive equipment allows evaluation of muscles and muscle groups in an isokinetic manner. Isokinetic muscle testing is performed with a constant speed of angular motion but variable resistance. Isokinetic dynamometers have been shown to produce relatively reliable data when testing simple, uniaxial joints, such as the knee, as well as when testing the spine in flexion and extension. Isokinetic strength data are generally not helpful in the diagnosis of orthopaedic abnormalities. Isokinetic testing can be helpful during the rehabilitation of orthopaedic patients, since it allows easy monitoring of progress. It also enables the patient to work on muscle rehabilitation in a controlled manner at higher speeds than are possible with more conventional exercise equipment. An isokinetic rehabilitation program can be easily tailored with concentric and eccentric components that closely resemble muscle actions during occupational and sports activities.

      • Subspecialty:
      • Sports Medicine

      • Spine

      • General Orthopaedics

    Management of Traumatic Foot Wounds.

    The foot is frequently exposed to direct trauma due to its role in weight-bearing. The soft-tissue wounds that commonly result interfere with ambulation due to complications such as tissue necrosis, scar formation, infection, and deformity. The five most common categories of foot injury are (1) low-velocity blunt trauma, (2) high-velocity blunt trauma, (3) low-velocity penetrating trauma, (4) high-velocity penetrating trauma, and (5) thermal injuries. For major wounds, the treatment is early aggressive debridement, copious irrigation, and skeletal stabi-lization with early coverage of skin defects. Local and systemic antibiotics are adjunctive to debridement to prevent infection. Prompt recognition and release of compartment syndrome of the foot are extremely important. Close observation is appropriate for wounds that appear minor on initial evaluation.

        • Subspecialty:
        • Trauma

        • Foot and Ankle

      Musculoskeletal Injuries in the Workplace: Defining Quality Care.

      Quality health care for a specific medical condition may be defined as adherence to an algorithm in which decision points are based on established medical practice as supported in the literature. The decision points can be considered either a "stan-dard of care" if there is definitive scientific evidence for their validity or a "guide-line for care" if there is only a consensus of medical opinion available. Algorithms for musculoskeletal injuries can be and have been successfully applied to patients in the workers' compensation setting. They can function as a concurrent surveil-lance system and are well accepted by physicians, patients, and industry if imple-mented by unbiased medical experts. A high level of quality care is attained by following such algorithms. Other goals achieved are early functional restoration as measured by return to work, a more efficient use of diagnostic studies, and avoidance of unnecessary therapeutic interventions, with the result that treatment is more cost-effective. Such a program that strives for high-quality care and emphasizes appropriate utilization will realize cost savings that may be far greater and longer lasting than the financial saving seen with arbitrary spending caps and fee controls.

          • Subspecialty:
          • Clinical Practice Improvement

        Restoration of Injured or Degenerated Articular Cartilage.

        Intra-articular fractures, ligamentous and meniscal injuries, and articular cartilage breakdown are major causes of degenerative joint disease. Lesions on the articular surface seem to have a limited capacity for repair and often progress inexorably toward osteoarthritis. Recent studies on joint immobilization and cartilage atrophy, however, have shown that repair and remodeling of articular cartilage may be possible. Currently used clinical methods of stimulating cartilage repair and remodeling include alteration of the loading on degenerated joints (primarily by using osteotomies), introduction of new cartilage-forming cells by perforation of subchondral bone, and soft-tissue arthroplasty. These procedures provide temporary relief in selected patients, but they often do not predictably restore long-term joint function. Experimentally, cartilage repair has been stimulated successfully with the use of allografts of periosteum and perichondrium, which serve as sources of cells with chondrogenic potential; introduction of cells grown in culture (stem cells or chondrocytes); stimulation by fibrin clot formation; artificial collagen matrices combined with cell transplants; and chondrogenic growth factors. The long-term success of all these methods has not been explored thoroughly, even in animal studies. Nevertheless, some research results are sufficiently encouraging to suggest that repair of the degenerating articular cartilage may be possible in the future.

            • Subspecialty:
            • Trauma

            • Adult Reconstruction

          Scaphoid Nonunion.

          The natural history and treatment of scaphoid fractures and subsequent nonunions have occupied a substantial portion of the orthopaedic literature. The authors examine the role of modern diagnostic tools in making an earlier diagnosis of scaphoid nonunion, in more accurately determining the displacement and angulation of the fragments, and in identifying the presence of avascular necrosis. They also consider the various available treatment modalities, including immobilization, electrical stimulation, both conventional and vascularized bone grafting, and internal fixation. Finally, a brief review of salvage procedures and the authors' preferred treatment are presented.

              • Subspecialty:
              • Trauma

              • Hand and Wrist

              • Basic Science

            Soft-Tissue Tumors: Diagnosis, Evaluation, and Management.

            Benign soft-tissue neoplasms and tumorlike conditions of the musculoskeletal system are common. Sarcomas are less frequent, with only 5,000 new cases diagnosed each year in the United States. After plain radiographs of the affected area have been obtained, magnetic resonance (MR) imaging (both T1- and T2-weighted sequences) is the best imaging modality for detecting and characterizing the lesion. Although MR imaging is not specific in determining whether lesions are benign or malignant, it can be useful in evaluating other characteristics, such as size, pattern of growth, integrity of natural boundaries, and homogeneity. Biopsy must be done carefully, so as not to adversely affect the outcome. Technical considerations include proper location and orientation of the biopsy incision, meticulous hemostasis, and frozen-section analysis to ensure that diagnostic material has been obtained. Effective treatment requires close coordination between the surgeon, the radiation oncologist, the pathologist, the plastic surgeon, and the diagnostic radiologist. Limb-salvage surgery has resulted in a local control rate greater than 90%. High-grade tumors that are larger than 5 cm in diameter have the worst prognosis. The role of chemotherapy remains controversial and unresolved.

                • Subspecialty:
                • Musculoskeletal Oncology

              Wear Debris in Total Joint Replacements.

              In vivo degradation of prosthetic implant materials is increasingly recognized as a major factor limiting the durability of total joint arthroplasty. In vivo degradation occurs primarily by means of wear processes that can generate large quantities of particulate debris. This debris can stimulate an adverse local host response leading to periprosthetic bone loss, which can compromise implant fixation and bone stock. The authors review the basic mechanisms of implant degradation and the host response to particulate degradation products, particularly in the context of the pathogenesis of osteolysis. Submicron polyethylene particles (mean size, 0.5 um) are the dominant type of wear particle present in periprosthetic tissues associated with uncemented hip replacements. Polyethylene wear can be minimized by improving the quality of the polyethylene, avoiding use of large-diameter (greater than 28 mm) femoral heads in total hip arthroplasty, and improving the design and fabrication of modular connections, which can be important sources of three-body wear particles. Advances in the understanding of the basic mechanisms of osteolysis are critical to the development of preventive measures that will minimize the clinical impact of this phenomenon.

                  • Subspecialty:
                  • Trauma

                  • Adult Reconstruction

                  • Basic Science

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