JAAOS

JAAOS, Volume 5, No. 5


Hip Osteotomies: A Biomechanical Consideration.

Proximal femoral and periacetabular osteotomies for the treatment of osteoarthrosis have produced varying clinical results. Because the underlying pathomechanics of osteoarthrosis are not yet fully understood, it is difficult to predict which type of osteotomy will most improve the biomechanical environment in a given situation. Osteotomies result in relatively small changes in joint load (10% to 20% at most), which probably do not govern tissue responses. However, osteotomies do change the distribution of the load (i.e., stresses) and, perhaps more important, stress gradients. These changes in contact and underlying stresses undoubtedly affect cartilage and bone adaptation. It is likely that the magnitude of stress and strain in cartilage and underlying bone can be altered in such a way that more predictable beneficial remodeling will occur. Emerging imaging and computational technologies may allow patient-specific modeling, which should improve the efficacy and durability of repair.

      • Subspecialty:
      • Adult Reconstruction

      • Basic Science

    Nerve Entrapment Syndromes of the Foot and Ankle.

    Nerve entrapment at the ankle and midfoot is an important, yet frequently underrecognized, source of foot pain. Familiarity with the nerve anatomy and known entrapment sites facilitates evaluation; local nerve lesions in the foot and ankle must be distinguished from proximal nerve dysfunction and systemic diseases that may affect nerve function. Treatment is directed toward reducing contact pressure from footwear and addressing other underlying problems, such as edema and ankle instability that may be contributing to nerve dysfunction.

        • Subspecialty:
        • Foot and Ankle

        • Pain Management

      Rheumatoid Arthritis of the Cervical Spine.

      Cervical involvement in patients with rheumatoid arthritis occurs primarily in the upper cervical spine. The characteristic deformities are atlantoaxial subluxation, vertical settling, and subaxial subluxation. The typical patient complaints are neck pain and occipital pain. Subtle signs of myelopathy may also be present. Useful radiologic studies include plain radiography, tomography, and functional magnetic resonance imaging. The most helpful radiographic measurements are the anterior atlantodens interval, the posterior atlantodens interval, and assessment of vertical settling. Atlantoaxial subluxation greater than 9 mm with vertical settling and a posterior atlantodens interval less than 14 mm correlate with neurologic deficit. Nonoperative management does not change the natural history of cervical disease. Traditional surgical indications include intractable pain and neurologic deficit. The author discusses more controversial indications and proposes a rationale and protocol for treatment. The primary surgical objectives are to achieve stabilization of the affected segments and to relieve neural compression by reduction of subluxations or direct decompression. Arthrodesis provides reliable pain relief. Neurologic recovery occurs more consistently in patients with lower grades of preoperative myelopathy.

          • Subspecialty:
          • Trauma

          • Spine

          • Pain Management

        Septic Arthritis of the Hip in Children.

        Recent advances in the management of septic arthritis of the hip in children include a better understanding of the effects of infection on articular cartilage; improvements in diagnostic tests, including erythrocyte sedimentation rate, C-reactive protein analysis, and ultrasonography; and more efficacious home intravenous and oral antibiotic therapy. Early diagnosis is essential to successful treatment. Needle aspiration is the most specific diagnostic test; however, false-negative results are possible. Prompt surgical drainage and postoperative antibiotic therapy until signs of infection resolve are necessary to prevent late sequelae. Surgical treatment of limb-length inequality is more useful than attempts to salvage the destroyed or incongruent joint.

            • Subspecialty:
            • Pediatric Orthopaedics

          Surgical Correction of Malunited Fractures of the Distal Radius.

          Malunion of a distal radius fracture may result in functional limitation and pain. Reestablishing the geometry of the metaphysis and the alignment of the articular surface, restoring the relationship at the distal radioulnar joint, and respecting the soft-tissue envelope are elements of a successful reconstruction. The author describes a systematic approach to evaluation and treatment, including the indications for surgical correction, techniques of reconstruction, and potential complications. Salient aspects of postsurgical rehabilitation and salvage procedures are discussed.

              • Subspecialty:
              • Trauma

              • Basic Science

            Traumatic Anterior Glenohumeral Instability: The Role of Arthroscopy.

            The static and dynamic stabilizers of the glenohumeral joint act together to ensure joint stability throughout the wide range of normal shoulder motion. These structures are functionally altered after a traumatic anterior shoulder dislocation, often resulting in recurrent instability. The arthroscope has enhanced the surgeon's ability to examine and repair the unstable glenohumeral joint. The rate of recurrence of instability after arthroscopic stabilization has historically been unacceptably high compared with that after open stabilization techniques. The authors offer a treatment algorithm and suggest guidelines for the use of arthroscopic techniques in the treatment of the unstable shoulder.

                • Subspecialty:
                • Trauma

                • Shoulder and Elbow

                • Basic Science

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