Patient specific instrumentation for corrective osteotomy in case of posttraumatic cubitus varus in children.

Malunion in cubitus varus most often results from inadequate supracondylar fracture reduction or from secondary displacement. Treatment of cubitus varus needs an accurate preoperative planning to obtain a good functional and esthetical outcome. Planning based on conventional radiology is source of inaccuracy and clinical results are variable. Developments of computer-assisted orthopaedic surgery (CAOS) and of patient specific instruments (PSI) have made accurate three dimensional (3D) preoperative simulation possible. This original technique based on 3D-osteotomy planning and using PSI was developed to correct cubitus varus deformity in the three dimensions. A 3D-model of the deformity was created based on a CT-scan of the distal humerus. Ideal correction was calculated by software and a PSI was designed. The PSI was used to guide the saw blade on the deformed bone. After resection of a wedge fragment, osteosynthesis was performed using two crossed K-wires. Elbow radiographs were performed at least six months after surgery. At the latest follow-up, the correction of cubitus varus obtained was satisfying in the five cases of our series and all the patients had pain free elbow mobility. Ulnar nerve palsy complicated the evolution in one patient, which fully recovered within 6 months. Advantages of this technique include a decreased operating time and a smaller surgical incision. More-over, results showed increased correction accuracy without the need of fluoroscopy during the osteotomy procedure. These benefits are counterbalanced by the need of a preoperative CT-scan of the distal humerus and the additional cost for the PSI.

Treatment of large diaphyseal bone defect of the tibia by the "fibula pro tibia" technique: application in developing countries.

Large segmental bone defects of the tibia may be due to infections, high-energy fractures, congenital diseases or tumors and represent a challenge for both the physician and the patient. In developing countries, the use of expansive techniques is not possible so that amputation is sometimes proposed. However, an alternative technique for limb salvage, applicable in developing countries consists of tibialization of the ipsilateral fibula. This technique is also called "Fibula pro Tibia", fibular transfer to the tibia or fibular centralization. We report this transfer in 4 patients with an average defect length of 11.8 cm. Union between the transferred fibula and the tibia was obtained in all patients, for both proximal and distal junctions, after an average time of 8.5 months (range, 4 to 18 months). Three patients returned to a normal walking function while one was still limping, but was able to walk independently without need of crutches.

Intra-articular osteoid osteoma mimicking juvenile arthritis.

In case of intra-articular osteoid osteoma, misdiagnosis as juvenile arthritis may occur, delaying adequate treatment. We report cases of intra-articular osteoid osteomas in children that were misdiagnosed and initially inappropriately treated with intra-articular corticoid injection. Diagnosis of osteoid osteoma was finally given by CT-scan and appropriate treatment by radiofrequency ablation or surgical ablation was performed. Clinicians and radiologists should be aware of the potentially confusing clinical and imaging findings associated with intra-articular osteoid osteoma.

MRI evaluation of resection margins in bone tumour surgery.

In 12 patients operated on for bone sarcoma resection, a postoperative magnetic resonance imaging of the resection specimens was obtained in order to assess the surgical margins. Margins were classified according to MRI in R0, R1, and R2 by three independent observers: a radiologist and two orthopaedic surgeons. Final margin evaluation (R0, R1, and R2) was assessed by a confirmed pathologist. Agreement for margin evaluation between the pathologist and the radiologist was perfect (κ = 1). Agreement between the pathologist and an experienced orthopaedic surgeon was very good while it was fair between the pathologist and a junior orthopaedic surgeon. MRI should be considered as a tool to give quick information about the adequacy of margins and to help the pathologist to focus on doubtful areas and to spare time in specimen analysis. But it may not replace the pathological evaluation that gives additional information about tumor necrosis. This study shows that MRI extemporaneous analysis of a resection specimen may be efficient in bone tumor oncologic surgery, if made by an experienced radiologist with perfect agreement with the pathologist.