A comparison of lateral column lengthening and medial translational osteotomy of the calcaneus for the reconstruction of adult acquired flatfoot.

BACKGROUND: This study compared the effects of lateral column lengthening and medial translational calcaneal osteotomy on pedal realignment and degeneration of adjacent hindfoot joints noted on radiographs. METHODS: Forty patients who had either a lateral column lengthening (25 feet) or calcaneal osteotomy (17 feet) to reconstruct a flatfoot were retrospectively reviewed as two groups. Six parameters of foot alignment were measured from weightbearing preoperative, early postoperative, and latest followup radiographs. The magnitude of realignment achieved initially and preserved at latest followup was determined for each group. The talonavicular and subtalar joints were graded for radiographic evidence of arthritis before the reconstruction and at latest followup. Demographic information, complication rate, and reoperation associated with each group also were determined by chart review. RESULTS: The group that received a lateral column lengthening demonstrated a greater initial realignment than the group treated with a calcaneal osteotomy. The lengthening group also demonstrated greater realignment than the osteotomized group when they were compared at their respective latest followup. The lengthening group had a higher number of adjacent joints with progression of arthritis. The rate of nonunion was higher with a lateral column lengthening; however, the rate of reoperation after an osteotomy was more than twice that observed after a lateral column lengthening. CONCLUSIONS: The lateral column lengthening group achieved greater realignment initially and maintained correction better over time than the calcaneal osteotomy group while having a lower reoperation rate despite a higher incidence of nonunion and radiographic progression of adjacent joint arthritis.

Static versus dynamic plating for multilevel anterior cervical discectomy and fusion.

BACKGROUND CONTEXT: Dynamic anterior plates have been popularized to promote cervical spine fusion by allowing controlled settling, thereby promoting load sharing across the construct. To date these proposed benefits have been largely theoretical and there are no studies confirming any benefits over more traditional static plates. PURPOSE: To compare the clinical and radiographic outcomes of patients undergoing an instrumented multilevel anterior cervical discectomy and fusion (ACDF) with either a static or dynamic plate design. STUDY DESIGN: A retrospective clinical and radiographic study. PATIENT SAMPLE: From 1997 to 2002, 52 patients with either radiculopathy or myelopathy underwent two- or three-level ACDF with either static or dynamic plate fixation. OUTCOME MEASURES: Functional outcome, fusion status, radiographic measurements. METHODS: A statically locked plating system was used in 21 patients, and a dynamic plating system was used in 31 patients. Functional outcome, fusion status, plate migration, settling, and adjacent-level disc space impingement were evaluated. RESULTS: Clinical outcome was found to be similar between the statically and dynamically plated groups. Eighty-four percent of patients in both groups experienced good or excellent results at final follow-up. We observed a higher rate of nonunion in patients treated with a dynamic plate (16% [5 of 31]) compared with a rate of 5% (1 of 21) in those patients treated with a static plate (p=.05). Settling of the construct and plate migration was similar between the study groups at all time points. CONCLUSIONS: This study failed to confirm our hypothesis that a dynamic plate (that allows angular motion between the screws and plate) confers any clinical or radiographic advantage over earlier design static plates. A higher rate of nonunion was actually seen in the dynamically plated patients; however, clinical results were similar between the two groups.

Gene therapy for spinal fusion.

Spinal fusion will continue to be an important part of the surgical treatment of spinal pathology for the foreseeable future. Traditional challenges to successful spinal fusion surgery include autograft donor site morbidity and pseudoarthrosis. Recent advances in the understanding of the biology of bone formation have allowed the development of therapeutic biologics. Although recombinant bone morphogenetic proteins delivered to the arthrodesis site will stimulate fusion, these proteins have been less successful in more challenging fusion situations (posterolateral), require supraphysiologic doses to promote fusion in humans, and are quite expensive. Gene therapy may represent the easiest method for the application of bone-forming biologic agents to promote spinal fusion. Both in vivo and ex vivo techniques of delivery of therapeutic genes have been used effectively to promote fusion in lower animals. Considerable research is required to identify gene therapy techniques and vectors with acceptable safety profiles and high fusion rates.