Aims

Aseptic loosening is a major cause of failure in cemented endoprosthetic reconstructions. This paper presents the long-term outcomes of a custom-designed cross-pin fixation construct designed to minimize rotational stress and subsequent aseptic loosening in selected patients. The paper will also examine the long-term survivorship and modes of failure when using this technique.

A total of 157 hindquarter amputations were carried out in our institution during the last 30 years. We have investigated the reasons why this procedure is still required and the outcome. This operation was used as treatment for 13% of all pelvic bone sarcomas. It was curative in 140 and palliative in 17, usually to relieve pain. There were 90 primary procedures (57%) with the remaining 67 following the failure of previous operations to control the disease locally. The indication for amputation in primary disease was for large tumours for which limb-salvage surgery was no longer feasible. The peri-operative mortality was 1.3% (n = 2) and major complications of wound healing or infection arose in 71 (45%) patients. The survival at five years after hindquarter amputation with the intent to cure was 45%, and at ten years 38%. Local recurrence occurred in 23 patients (15%). Phantom pain was a significant problem, and only 20% used their prosthesis regularly. Functional scores were a mean of 57%. With careful patient selection the oncological results and functional outcomes of hindquarter amputation justify its continued use.

Cite this article: Bone Joint J 2013;95-B:127–31.

We reviewed 25 patients in whom a MUTARS megaprosthesis with a conical fluted stem had been implanted. There were three types of stem: a standard stem was used in 17 cases (three in the proximal femur, nine in the distal femur and five proximal tibia), a custom-made proximal femoral stem in four cases and a custom-made distal femoral stem in four cases. The mean age of the patients was 40.1 years (17 to 70) and the mean follow-up was for 2.5 years (0.9 to 7.4).

At follow-up two patients had died from their disease: one was alive with disease and 22 were disease-free. One of 23 prostheses had been removed for infection and another revised to a cemented stem. The mean Musculoskeletal Tumor Society score was 24.9 (12 to 30) and the mean Karnofsky index was 82% (60% to 100%).

There was no radiological evidence of loosening or subsidence. Stem stress shielding was seen in 11 patients and was marked in five of these.

There were five complications, rupture of the extensor mechanism of the knee after extra-articular resection in two patients, deep venous thrombosis in one, septic loosening in one, and dislocation of the hip in one.

The survival rate after seven years was 87% (95% confidence interval (CI) 83 to 91) for the patients and 95% (95% CI 91 to 99) for the megaprosthesis. A longer follow-up is needed to confirm these encouraging results.

We undertook a cemental unipolar proximal femoral endoprosthetic replacement in 131 patients with a mean age of 50 years (2 to 84). Primary malignant tumours were present in 54 patients and 67 had metastatic disease. In addition, eight patients had either lymphoma or myeloma and two had non-oncological disorders. The mean follow-up was 27 months (0 to 180). An acetabular revision was required later in 14 patients, 12 of whom had been under the age of 21 years at the time of insertion of their original prosthesis. The risk of acetabular revision in patients over 21 years of age was 8% at five years compared with 36% in those aged under 21 years. All the unipolar hips in this younger age group required revision within 11 years of the initial operation.

We conclude that unipolar replacement should not be used in younger patients and should be avoided in patients with a life expectancy of more than five years.

We have analysed the pattern of symptoms in patients presenting with synovial sarcoma to identify factors which led to long delays in diagnosis. In 35 children, the early symptoms and the results of clinical and radiological investigation were reviewed, along with the presumed diagnoses. The duration of symptoms was separated into patient delay and doctor delay.

Only half of the patients had one or more of the four clinical findings suggestive of sarcoma according to the guidance of the National Institute for Clinical Excellence at the onset of symptoms. Of the 33 children for whom data were available, 16 (48.5%) presented with a painless mass and in ten (30.3%) no mass was identified. Seven (21.2%) had an unexplained joint contracture. Many had been extensively investigated unsuccessfully. The mean duration of symptoms was 98 weeks (2 to 364), the mean patient delay was 43 weeks (0 to 156) and the mean doctor delay was 50 weeks (0 to 362). The mean number of doctors seen before referral was three (1 to 6) and for 15 patients the diagnosis was obtained after unplanned excision. Tumours around the knee and elbow were associated with a longer duration of symptoms and longer doctor delay compared with those at other sites. Delays did not improve significantly over the period of our study of 21 years, and we were unable to show that delay in diagnosis led to a worse prognosis.

Our findings highlight the variety of symptoms associated with synovial sarcoma and encourage greater awareness of this tumour as a potential diagnosis in childhood.

We investigated whether our policy of routine re-excision of the tumour bed after an unplanned excision of a soft-tissue sarcoma was justified.

Between April 1982 and December 2005, 2201 patients were referred to our hospital with the diagnosis of soft-tissue sarcoma, of whom 402 (18%) had undergone an unplanned excision elsewhere. A total of 363 (16.5%) were included in this study. Each patient was routinely restaged and the original histology was reviewed. Re-excision was undertaken in 316 (87%). We analysed the patient, tumour and treatment factors in relation to local control, metastasis and overall survival.

Residual tumour was found in 188 patients (59%). There was thus no residual disease in 128 patients of whom 10% (13) went on to develop a local recurrence. In 149 patients (47%), the re-excision specimen contained residual tumour, but it had been widely excised. Local recurrence occurred in 30 of these patients (20%). In 39 patients (12%), residual tumour was present in a marginal resection specimen. Of these, 46% (18) developed a local recurrence. A final positive margin in a high-grade tumour had a 60% risk of local recurrence even with post-operative radiotherapy.

Metastases developed in 24% (86). The overall survival was 77% at five years. Survival was related to the grade of the tumour and the finding of residual tumour at the time of re-excision.

We concluded that our policy of routine re-excision after unplanned excision of soft-tissue sarcoma was justified in view of the high risk of finding residual tumour.

Aims

Pelvic reconstruction after the resection of a tumour around the acetabulum is a challenging procedure due to the complex anatomy and biomechanics. Several pelvic endoprostheses have been introduced, but the rates of complication remain high. Our aim was to review the use of a stemmed acetabular pedestal cup in the management of these patients.

To date, all surgical techniques used for reconstruction of the pelvic ring following supra-acetabular tumour resection produce high complication rates. We evaluated the clinical, oncological and functional outcomes of a cohort of 35 patients (15 men and 20 women), including 21 Ewing’s sarcomas, six chondrosarcomas, three sarcomas not otherwise specified, one osteosarcoma, two osseous malignant fibrous histiocytomas, one synovial cell sarcoma and one metastasis. The mean age of the patients was 31 years (8 to 79) and the latest follow-up was carried out at a mean of 46 months (1.9 to 139.5) post-operatively.

We undertook a functional reconstruction of the pelvic ring using polyaxial screws and titanium rods. In 31 patients (89%) the construct was encased in antibiotic-impregnated polymethylmethacrylate. Preservation of the extremities was possible for all patients. The survival rate at three years was 93.9% (95% confidence interval (CI) 77.9 to 98.4), at five years it was 82.4% (95% CI 57.6 to 93.4). For the 21 patients with Ewing’s sarcoma it was 95.2% (95% CI 70.7 to 99.3) and 81.5% (95% CI 52.0 to 93.8), respectively. Wound healing problems were observed in eight patients, deep infection in five and clinically asymptomatic breakage of the screws in six. The five-year implant survival was 93.3% (95% CI 57.8 to 95.7). Patients were mobilised at a mean of 3.5 weeks (1 to 7) post-operatively. A post-operative neurological defect occurred in 12 patients. The mean Musculoskeletal Tumor Society score at last available follow-up was 21.2 (10 to 27).

This reconstruction technique is characterised by simple and oncologically appropriate applicability, achieving high primary stability that allows early mobilisation, good functional results and relatively low complication rates.

Cite this article: Bone Joint J 2013;95-B:1410–16.

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