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INTRODUCTION: Secondary chondrosarcoma is a rare entity arising from a pre-existing cartilaginous lesion. Transformation of an osteochondroma to a chondrosarcoma occurs in <1% of cases. Sciatica is a common problem that can cause significant pain, weakness, and numbness. CASE REPORT: A 36-year-old male presented to the Orthopedic Oncology Service after being treated for sciatica for 3 years. Magnetic resonance imaging of the lumbar spine demonstrated degenerative disc disease with mild inferior foraminal narrowing at L5-S1. He had undergone multiple epidural steroid injections without improvement in his symptoms. A chondrosarcoma encasing the peroneal nerve was found arising from an underlying osteochondroma in the proximal fibula. The patient underwent resection of the tumor which included resection of the peroneal nerve. Five years after resection, the patient is disease free and uses an ankle-foot orthosis for ambulation. CONCLUSION: This case demonstrates the importance of evaluating a patient with peripheral nerve symptoms for a lesion within the involved extremity along the entire length of the nerve. Extraspinal lesions can compress peripheral nerves and cause radicular symptoms. Timely treatment is important to prevent malignant transformation or worsening of the tumor as well as to provide better functional outcome.

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Carbon fiber reinforced implants have emerged as an alternative to traditional stainless steel and titanium implants because of the improved visibility on advanced imaging and excellent biomechanical strength. This can be advantageous in patients with concern about fracture healing, tumor recurrence, or additional imaging requirements. However, limited long-term data are available to present complications from the use of these implants. We present the case of a failure of a carbon fiber reinforced intramedullary femoral nail used in a closed distal femur fracture.

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Traditionally, intercalary allograft reconstruction after tumor resection has had a high rate of complications, particularly nonunion. Plate and intramedullary nail fixation have been used alone and in combination to improve union rates. This study sought to evaluate a new technique that uses a magnetic growing intramedullary nail to compress the osteotomy sites to aid in healing and to answer 2 questions: (1) What is the union rate and the time to union when using magnetic growing intramedullary nails? (2) What complications occur with this technique? Eight patients with 15 osteotomy sites with a minimum follow-up of 14 months were retrospectively reviewed. Seven of the 8 patients underwent initial reconstruction with the magnetic nail, whereas 1 patient underwent treatment of a nonunion that occurred with prior carbon fiber nail fixation. Twelve of the 15 osteotomy sites had healed by an average of 9 months. Nonunions occurred in 2 patients with an associated failure of the hardware. One of these patients healed after revision surgery. Of the patients who healed at both sites, 1 had a fracture through the allograft, 1 had backing out of a locking screw that required removal, and 1 required a manipulation under anesthesia of the knee. Two patients underwent successful limb lengthening needed because of an expected limb-length discrepancy after healing occurred. Use of growing intramedullary nails in compression mode led to an 87% union rate at final follow-up with acceptable complications. This technique provides a viable alternative to standard nail and plate fixation when intercalary allografts are used. [Orthopedics. 2018; 41(6):330-335.].

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PURPOSE: To evaluate if redirecting a Kirschner wire (K-wire) through the same proximal hole will weaken the pull-out force and to test if multiple redirections will result in a continued stepwise decrease in pull-out force. METHODS: An Instron was used to test the pull-out force of K-wires using the peak initial failure load as a measure of failure of K-wire fixation. K-wires 0.062 inches in diameter were inserted with an angled drill guide into a bicortical bone substrate. Trials were divided into 7 groups with the first group having the K-wires placed through both cortices and then tested without redirection. In groups 2-6, the K-wire was placed bicortically and then withdrawn and redirected through the same proximal hole with 1, 2, 3, 4, and 5 redirections. A control group in which the K-wire was only unicortical was also tested. RESULTS: Compared with the control group of no redirects, any number of redirections weakened the pull-out force. There was no difference between redirected groups and the unicortical group. When comparing between redirections, there were no significant differences in pull-out force. Regression analysis showed that, after the first redirection, there was no stepwise change in pull-out force with additional redirection. CONCLUSIONS: There was a significant decrease in pull-out force with any redirections, but there was no stepwise decrease in failure force after multiple redirections. The failure force of any redirection was similar to a unicortically placed wire. CLINICAL RELEVANCE: Any K-wire redirection attempts in hand bone fixation can result in a considerably weakened construct.

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