Early failure modalities in hip resurfacing?

Between 1996 and 2002, we treated 60 patients (65 hips) by hip resurfacing. The notes and radiographs of these cases were studied retrospectively and the modalities of failure identified. At a mean follow-up of 51 months, 14 of these cases (22%) required revision surgery. One patient had died from unrelated causes and one was lost to follow-up. At the time of primary surgery, the mean age of the patients in our series was 55 years. The commonest mechanism of failure in our series was fractured neck of femur (six cases). Four of these occurred in females over the age of 60. None of the fractured necks of femur were associated with trauma. There were four cases of loose acetabular components and one case of progressive AVN (avascular necrosis). Two patients required revision surgery for ongoing hip pain and one required a twostage revision for early deep infection. (Hip International 2005; 15: 155-8).

Risk factors for survival and local control in chondrosarcoma of bone.

We studied 153 patients with non-metastatic chondrosarcoma of bone to determine the risk factors for survival and local tumour control. The minimum follow-up was for five years; 52 patients had axial and 101 appendicular tumours. Surgical treatment was by amputation in 27 and limb-preserving surgery in 126. The cumulative rate of survival of all patients, at 10 and 15 years, was 70% and 63%, respectively; 40 patients developed a local recurrence between 3 and 87 months after surgery and 49 developed metastases. Local recurrence was associated with poor survival in patients with concomitant metastases but not in those without. On multivariate analysis independent risk factors for rates of survival include extracompartmental spread, development of local recurrence and high histological grade. Independent risk factors for local recurrence include inadequate surgical margins and tumour size greater than 10 cm. Location within the body, the type of surgery and the duration of symptoms are of no prognostic significance. Surgical excision with an oncologically wide margin provides the best prospect both for cure and local control in these patients.

Variables affecting simulated use determination of residual ethylene oxide in medical devices.

In autumn 1993, AAMI/ST/WG 63, Sterilization Residuals Working Group undertook the task of studying factors involved in determining the amount of residual ethylene oxide in medical devices after sterilization and developing a protocol for controlling the relevant variables. The protocol was evaluated by conducting a round robin study consisting of 8 participating laboratories from around the country. Results of this round robin study demonstrated the range over which results may vary despite controls placed on the time and temperature at which determinations were conducted. The data from the study suggest that small, random variations in technique during short sample extraction times can lead to variability in the results. Variables such as initial water temperature, oven temperature, weighing of sample, and length of extraction should be carefully controlled. Inherent variations in the material composition of similar devices are possible contributing factors. The efforts of this working group and the subsequent evaluation and discussion of its findings are presented.

Experience in the treatment of dedifferentiated chondrosarcoma.

Dedifferentiated chondrosarcoma is a rare, highly malignant variant of chondrosarcoma in which a high-grade spindle-cell sarcoma coexists with a lower-grade chondroid tumour. We have reviewed our experience with this neoplasm in 22 patients, all of whom were treated using modern oncological principles of planned resection and chemotherapy. Despite this the median survival was under nine months and only 18% were alive at five years. Those patients who received chemotherapy, and in whom wide margins of excision were achieved at operation, did best. It is essential to have an accurate preoperative diagnosis in order to plan treatment which may offer a better prospect of cure.

Synovial sarcoma arising in association with a popliteal cyst.

Synovial sarcoma is a relatively common soft tissue sarcoma particularly in the adolescent and young adult. We report an unusual case of a synovial sarcoma arising within a popliteal cyst in a 13-year-old female presenting with bilateral popliteal cysts. MR imaging demonstrated the cyst with evidence of subacute haemorrhage and a discrete nodule of tumour.

The two-stage ipsilateral fibular transfer for tibial defect following tumour excision.

Method. We performed a two-stage vascularized ipsilateral fibular graft transfer for segmental tibial defect following excision of malignant bone tumours.Results. We report 10 patients who had this procedure with an average follow-up of 116 months.The graft was transposed medialy on its vascular pedicle by two-stage surgery. Full weight bearing was achieved in six patients at 8-43 months postoperatively, but every patient had a significant complication.Discussion. The use of this method in isolation is not recommended for reconstruction of the tibia following tumour excision.

Extensible endoprostheses of the humerus after resection of bone tumours.

We carried out extensible endoprosthetic replacement of the proximal or total humerus in 18 children aged between six and 12 years, after resection of primary bone tumours mainly for osteosarcoma and Ewing's sarcoma. In 11 patients we performed 44 lengthening procedures, with an average of two per child annually and a mean total extension of 29.9 mm per patient. We were able to achieve lengthening of the operated limb with few complications and a mean functional rating of 79.3% according to the Enneking system. Progressive lengthening of these prostheses does not adversely affect the overall function of the arm, and superior subluxation of the head of the prosthesis has not been a problem.

Clear cell chondrosarcoma of bone.

Purpose. Clear cell chondrosarcoma is a rare variant of chondrosarcoma. Six cases are herein reported.Subjects. We have treated six patients with clear cell chondrosarcoma in the past 28 years, representing 1.6% of all chondrosarcomas seen in this time period.Results and Discussion. Half the patients had been initially underdiagnosed and inappropriately treated.Conclusions. Our results and our review of the literature highlight the fact that inadequate initial treatment leads to a high rate of both local recurrence and metastasis whilst wide initial excision is usually curative.