Single-screw Fixation of Adolescent Salter-II Proximal Humeral Fractures: Biomechanical Analysis of the "One Pass Door Lock" Technique.

BACKGROUND: Pin fixation of Salter-II proximal humeral fractures in adolescents approaching skeletal maturity has potential complications that can be avoided with single-screw fixation. However, the strength of screw fixation relative to parallel and diverging pin fixation is unknown. To compare the biomechanical fixation strength between these fixation modalities, we used synthetic composite humeri, and then compared these results in composite bone with cadaveric humeri specimens. METHODS: Parallel pinning, divergent pinning, and single-screw fixation repairs were performed on synthetic composite humeri with simulated fractures. Six specimens of each type were tested in axial loading and other 6 were tested in torsion. Five pair of cadaveric humeri were tested with diverging pins and single screws for comparison. RESULTS: Single-screw fixation was statistically stronger than pin fixation in axial and torsional loading in both composite and actual bone. There was no statistical difference between composite and cadaveric bone specimens. CONCLUSION: Single-screw fixation can offer greater stability to adolescent Salter-II fractures than traditional pinning. CLINICAL RELEVANCE: Single-screw fixation should be considered as a viable alternative to percutaneous pin fixation in transitional patients with little expected remaining growth.

A Destructive Tumor of the Proximal Tibia and Fibula: A Case Report Highlighting Challenging Diagnosis and Treatment of a Locally Advanced, Non-recurrent Chondroblastoma in 16 Years Old Patient.

INTRODUCTION: Chondroblastoma is a rare, cartilaginous primary bone tumor, which presents predominantly in children and young adults. These tumors represent 1% of all primary bone tumors. Patients tend to complain of progressive joint pain which usually aids in early diagnosis. However, early diagnosis has made the understanding of the untreated, progressive course of chondroblastoma quite difficult. This case report highlights a patient who was first encountered with locally advanced chondroblastoma and discusses the challenges of diagnosis and treatment with a focus on the natural progression of this disease. CASE REPORT: We report the case of a 16-year-old male encountered during relief efforts after the 2010 Haiti earthquake, who was found to have a massive, expansile, and destructive mass of the proximal left tibia and fibula. Radiographic appearance was concerning for a malignant bone forming process. However, biopsy revealed features most consistent with chondroblastoma with secondary aneurysmal bone cyst formation. Marginal resection was considered, but the degree of soft tissue and neurovascular invasion made it impossible to salvage the leg and thus an above-the-knee amputation was performed. CONCLUSION: This report reviews the challenging diagnosis of a massive chondroblastoma with locally aggressive features which required ablative surgery. This may provide insight into the untreated, natural course of this pathology.

Scoliosis Secondary to Dystonia: A Case Report and Review of the Literature.

CASE: An adolescent girl presented with an atypical scoliotic curve, pelvic obliquity, back pain, and lower-extremity paresthesias. A workup revealed generalized primary torsion dystonia. The condition was refractory to medical treatment and necessitated implantation of a deep brain stimulator. The scoliosis required operative correction, and the patient underwent posterior spinal arthrodesis with hook-rod instrumentation, which resulted in successful correction through 7 years of follow-up. CONCLUSION: The differential diagnosis for adolescent scoliosis should include dystonia as a potential cause, especially when a patient presents with muscular contractures, an atypical scoliotic curve, pelvic obliquity, or changing curve characteristics.