JAAOS, Volume 18, No. 10

Pedicle Screwbased Posterior Dynamic Stabilization inthe Lumbar Spine

Traditionally, management of spinal pathology has centered on decompression,correction of deformity, and stabilization. Deformity correction and stabilizationhave been accomplished largely by spinal fusion at the pathologic levels.In addition to the risks and potential complications, there are sequelae toa successful fusion. Therefore, attention is being directed toward disk replacementin the lumbar spine. In addition to their preserving motion in the anteriorcolumn, several posterior motionpreservation devices have been developedin an effort to prevent pathologic motion at both a decompressed level anda segment adjacent to a fusion. Initial studies suggest that the results ofposterior dynamic stabilization may be comparable to those of fusion; however,longer periods of clinical and radiographic follow-up are required to fullydefine the role these devices may play in the management of the degenerativelumbar spine.

      • Subspecialty:
      • Spine

    An Electronic Orthopaedic In-Training Examination

    Following nearly 1 year of development, trials, surveys, and educationalprograms, in November 2009, the orthopaedic in-training examination (OITE)was successfully converted from the traditional print format and administeredby DVD-ROM on local computers to more than 4,300 residents in 20 countries.A resident survey indicated a high level of satisfaction with the new examination.Questions with video and multislice image formats, presented as trial questions,performed well. Future versions of the OITE on DVD-ROM will eliminate someof the few difficulties experienced in 2009. The new electronic format offersexcellent possibilities for improved imaging, the development of new and innovativequestions, and an enhanced ability to approximate the practice environmentallof which can result in a better assessment of orthopaedic medical knowledgeand an improved educational experience.

        • Subspecialty:
        • Clinical Practice Improvement

      Distal Femoral Fractures: Current Concepts

      The diversity of surgical options for the management of distal femoralfractures reflects the challenges inherent in these injuries. These fracturesare frequently comminuted and intra-articular, and they often involve osteoporoticbone, which makes it difficult to reduce and hold them while maintaining jointfunction and overall limb alignment. Surgery has become the standard of carefor displaced fractures and for patients who must obtain rapid return of kneefunction. The goal of surgical management is to promote early knee motionwhile restoring the articular surface, maintaining limb length and alignment,and preserving the soft-tissue envelope with a durable fixation that allowsfunctional recovery during bone healing. A variety of surgical exposures,techniques, and implants has been developed to meet these objectives, includingintramedullary nailing, screw fixation, and periarticular locked plating,possibly augmented with bone fillers. Recognition of the indications and applicationsof the principles of modern implants and techniques is fundamental in achievingoptimal outcomes.

          • Subspecialty:
          • Trauma

        Secondary Chondrosarcoma

        Secondary chondrosarcoma is a distinctive type of tumor that originatesfrom a preexisting cartilaginous lesion. Most commonly, it is associated withsolitary or multiple osteochondromas. A fraction of cases arises from otherconditions, such as Maffucci syndrome and Ollier disease. A sudden increasein the size of the cartilaginous cap of an osteochondroma is a sign of malignanttransformation to secondary chondrosarcoma. However, there is no strict cutoffin terms of thickness of the cartilaginous cap that can be regarded as beingpathognomonic of malignancy. Most cases of secondary chondrosarcoma are lowto intermediate grade. Distant metastasis is uncommon, and the prognosis isgood for most patients. Overall survival at 5 years is approximately 90%.Surgical resection with wide margins is the best treatment option, but localrecurrence remains a significant problem in approximately 10% to 20% of patients.Patients with secondary chondrosarcoma of the pelvis are especially at riskfor local recurrence.

            • Subspecialty:
            • Musculoskeletal Oncology

          Cervical Disc Arthroplasty

          This technology overview addressed four questions that compared the differencein outcomes between patients undergoing cervical disc arthroplasty with patientsundergoing anterior cervical diskectomy fusion. Most studies did not eitherreport or conduct the appropriate statistical analyses to examine predictivecharacteristics in patients with successful clinical outcomes. Most studieswere inconclusive or unreliable regarding clinical outcomes and revision and/orcomplication rates in patients who present with neck and/or arm pain. No significantdifference in the length of hospital stay was reported; however, two studiesincluded in the overview reported that patients treated with cervical discarthroplasty returned to work in significantly fewer days (range, 14 to 16days) than did patients treated with anterior cervical diskectomy fusion.

              • Subspecialty:
              • Spine