Effect of Calcaneus Fracture Gap Without Step-Off on Stress Distribution Across the Subtalar Joint.

BACKGROUND: Subtalar arthritis is a common consequence following calcaneal fracture, and its development is related to the severity of the fracture. Previous calcaneal fracture models have demonstrated altered contact characteristics when a step-off is created in the posterior facet articular surface. Changes in posterior facet contact characteristics have not been previously characterized for calcaneal fracture gap without step-off. METHODS: The contact characteristics (peak pressure, area of contact, and centroid of pressure) of the posterior facet of the subtalar joint were determined in 6 cadaveric specimens. After creating a calcaneal fracture to simulate a Sanders type II fracture, the contact characteristics were determined with the posterior facet anatomically reduced followed by an incremental increase in fracture gap displacement of 2, 3, and 5 mm without a step-off of the articular surface. RESULTS: Peak pressure on the medial fragment was significantly less with a 5-mm gap compared to a 2- or 3-mm gap, or reduced. On the lateral fragment, the peak pressure was significantly increased with a 5-mm gap compared to a 2- or 3-mm gap. Contact area significantly changed with increased gap. CONCLUSION: In this study, there were no significant differences in contact characteristics between a <3-mm gap and an anatomically reduced fracture, conceding the study limitations including limiting axial loading to 50% of donor body weight. CLINICAL RELEVANCE: A small amount of articular incongruity without a step-off can be tolerated by the subtalar joint, in contrast to articular incongruity with a step-off present.

Force in the Scapholunate Interosseous Ligament During Active Wrist Motion.

PURPOSE: To examine the force experienced by the scapholunate interosseous ligament (SLIL) during movements of the wrist. METHODS: Six fresh-frozen cadaveric wrists were freed of soft tissue and tested in a computer controlled, servohydraulic simulator. Each wrist was tested cyclically through simulated active arcs of flexion-extension and dart throw motion. Tensile forces were recorded across the scapholunate joint with the SLIL cut through a cable placed through the scaphoid to the lunate and fixed to a force transducer external to the wrist. RESULTS: The average recorded maximal tensile force across the scapholunate joint during all tested motions was 20 N. During wrist flexion-extension and the dart throw motion, SLIL force was greater at maximum extension than at maximum flexion. No significant differences among the different motions at maximum flexion or extension or for maximal force during motion were found. CONCLUSIONS: Forces during the flexion-extension and dart throw motions were significantly higher in extension than in flexion. However, during simple unresisted wrist motions, the force did not exceed 20 N. CLINICAL RELEVANCE: This information can be used to evaluate surgical methods used for SLIL repairs and thus provide better outcomes for patients.

Cetuximab, paclitaxel, carboplatin, and radiation for head and neck cancer: a survival analysis of a Brown University Oncology Group phase II study.

OBJECTIVES: To assess the effect on progression-free and overall survival from the addition of cetuximab to paclitaxel-based chemoradiation for patients with squamous cell head and neck cancer from Brown University Oncology Group studies. METHODS: BrUOG HN-204 patients with stage III or IV locally advanced squamous cell cancer of the head and neck without distant organ metastases received 4 weeks of induction cetuximab followed by weekly cetuximab, paclitaxel, carboplatin, and concurrent radiation. Recurrence and survival data were compared with previous Brown University studies utilizing the same paclitaxel-based chemoradiation with and without induction chemotherapy. RESULTS: The progression-free survival and overall survival at 3 years for all 37 patients initiating chemoradiation was 54% and 57%, respectively. All surviving patients were followed for at least 3 years and the median follow-up is 4.4 years. Of 14 patients who recurred within 3 years, 7 patients recurred locally only, 5 had a systemic recurrence, and 2 recurred both locally and systemically. CONCLUSIONS: The addition of cetuximab to paclitaxel, carboplatin, and radiation achieves overall survival that is virtually identical to prior Brown University Oncology Group studies of paclitaxel-based chemoradiation without cetuximab. Improvements in locoregional control are needed despite the use of 3 agents to enhance the effects of radiation.

Cetuximab, paclitaxel, carboplatin, and radiation for head and neck cancer: a toxicity analysis.

OBJECTIVE: To determine the feasibility and toxicity of the addition of cetuximab to paclitaxel, carboplatin, and concurrent radiation for patients with head and neck cancer. MATERIALS AND METHODS: Patients with stage III or IV locally advanced squamous cell cancer of the head and neck, without distant organ metastases, were eligible. Patients received 4 weeks of induction cetuximab followed by weekly cetuximab, paclitaxel, carboplatin, and concurrent radiation. RESULTS: Thirty-two patients were assessable for chemoradiation toxicities. Grade 3 and grade 4 mucositis occurred in 53% and 16% of patients, respectively. Grade 3 and grade 4 radiation dermatitis occurred in 44% and 9% of patients, respectively. Grade 3/4 radiation dermatitis was associated with the use of intensity modulated radiation therapy (64% vs.14%, respectively, P < 0.0001). Grade 3 and grade 4 cetuximab associated acneiform rash developed in 6% and 3% of patients. Overall 21 patients (66%) had any grade 3 toxicity and 10 patients (31%) had any grade 4 toxicity. The percentages of the intended total dose delivered of carboplatin, cetuximab, paclitaxel, and radiation were 86%, 89%, 89%, and 96%, respectively. CONCLUSION: Cetuximab, when combined with paclitaxel, carboplatin and intensity modulated radiation therapy, increases dermatologic toxicity but does not increase mucosal toxicity as compared with previous Brown University Oncology Group studies of paclitaxel, carboplatin, and conventional radiation for patients with head and neck cancer.