A. Abudu

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.

Endoprosthetic Reconstruction for the Treatment of Musculoskeletal Tumors of the Appendicular Skeleton and Pelvis

BACKGROUND Excision of a bone tumor requires reconstruction if limb salvage is a priority. Reconstruction with an endoprosthetic implant is preferred in our unit, as the patient typically can return rapidly to full weight-bearing and functional activities. Long-term complications, such as deep infection, aseptic loosening, and mechanical failure of the implants, have led to concerns about the efficacy of reconstruction and the ability to revise failed implants while maintaining limb salvage in the longer term. The purpose of this study was to investigate the survival of endoprosthetic reconstructions in the medium to long term in order to determine the factors associated with their failure. METHODS A consecutive series of 776 patients underwent endoprosthetic reconstruction following resection of a bone tumor at a minimum of ten years prior to this investigation. One hundred and nine children with a so-called growing endoprosthesis were excluded as they often require revision to an adult prosthesis near skeletal maturity. Six patients were excluded because of a lack of adequate follow-up data, leaving 661 patients for analysis. Kaplan-Meier survival analysis of the implant was performed, with implant revision for any cause (infection, local recurrence, and mechanical failure), mechanical failure alone, and amputation used as the end points. RESULTS The mean duration of follow-up was fifteen years for patients who survived the original disease. Two hundred and twenty-seven patients (34%) had revision surgery because of mechanical failure (116 patients), infection (seventy-five patients), and locally recurrent disease (thirty-six patients). Implant survival at ten years was 75% with mechanical failure as the end point and 58% with failure from any cause as the end point. The limb salvage rate was 84% at twenty years. CONCLUSIONS We believe these medium to long-term results with first-generation endoprostheses are encouraging and justify the continued use of endoprostheses for reconstruction following the excision of a bone tumor.

The effect of an unplanned excision of a soft-tissue sarcoma on prognosis

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.

Endoprosthetic replacement of the proximal humerus. Long-term results.

We studied 100 patients who had undergone endoprosthetic replacement of the proximal humerus between 1976 and 1998. The outcome was assessed with regard to the survivorship of the patients, the salvaged limbs and the prostheses. Function was determined in the 47 surviving patients, of whom 30 were assessed using the Musculo-Skeletal Tumour Society (MSTS) rating scale and 38 completed the Toronto Extremity Salvage Score (TESS) questionnaire. The median age of the patients was 34 years (10 to 80). The mean follow-up period for surviving patients was nine years (2 to 20). The mean MSTS score at follow-up was 79% and the mean TESS score was 72%. The length of bone which was resected influenced the functional outcome. Abduction of the shoulder was to 45 degrees in most patients. The overall survival was 42% at ten years and that of the limb without amputation 93%. The survival of the prostheses using mechanical failure as the endpoint was 86.5% at 20 years. Endoprosthetic replacement of the proximal humerus is a predictable procedure providing reasonable function of the arm with a low rate of complications at long-term follow-up.

Post operative infection and increased survival in osteosarcoma patients: are they associated?

Despite neo-adjuvant chemotherapy osteosarcomas having significant mortality, recent studies have shown survival advantages following infections for some tumour types. This study investigates the effect of post-operative infection in patients treated for osteosarcoma using endoprosthetic replacement and neo-adjuvant chemotherapy. A consecutive series of 547 patients underwent surgery between 1981 and 2001 for osteosarcoma. Patients were excluded from the study if over 60 years old at diagnosis (n = 14) as they would not routinely receive chemotherapy. Studies showed that 70% of deep infections occur within one year from reconstruction. Therefore landmark analysis was performed; all patients infected after 12 months of reconstruction were excluded (15 patients, 2.7%) and those who died within 12 months from diagnosis due to metastases were excluded (105 patients, 19.2%), leaving 412 patients. Any survival advantage of early infection was analysed by Kaplan-Meier survival analysis from this landmark point. Overall population survival was 65% at 10 years after landmarking. There were 41 patients (10%) who developed an infection within one year of implantation. These patients had significantly better survival (p = 0.017). The 10-year survival for patients with osteosarcoma with infection was 84.5% compared to 62.3% in the non-infected group after landmarking. There was no significant difference in the percentage post-chemotherapy specimen necrosis between the two groups (p = 0.36). Infection was an independent prognostic factor on cox regression analysis. There was evidence for increased survival after deep post-operative infection in osteosarcoma patients, in keeping with other research. The authors feel this warrants further investigation.

Modular endoprosthetic replacement for tumours of the proximal femur

Endoprosthetic replacement of the proximal femur may be required to treat primary bone tumours or destructive metastases either with impending or established pathological fracture. Modular prostheses are available off the shelf and can be adapted to most reconstructive situations for this purpose. We have assessed the clinical and functional outcome of using the METS (Stanmore Implants Worldwide) modular tumour prosthesis to reconstruct the proximal femur in 100 consecutive patients between 2001 and 2006. We compared the results with the published series for patients managed with modular and custom-made endoprosthetic replacements for the same conditions. There were 52 males and 48 females with a mean age of 56.3 years (16 to 84) and a mean follow-up of 24.6 months (0 to 60). In 65 patients the procedure was undertaken for metastases, in 25 for a primary bone tumour, and in ten for other malignant conditions. A total of 46 patients presented with a pathological fracture, and 19 presented with failed fixation of a previous pathological fracture. The overall patient survival was 63.6% at one year and 23.1% at five years, and was significantly better for patients with a primary bone tumour than for those with metastatic tumour (82.3% vs 53.3%, respectively at one year (p = 0.003)). There were six early dislocations of which five could be treated by closed reduction. No patient needed revision surgery for dislocation. Revision surgery was required by six (6%) patients, five for pain caused by acetabular wear and one for tumour progression. Amputation was needed in four patients for local recurrence or infection. The estimated five-year implant survival with revision as the endpoint was 90.7%. The mean Toronto Extremity Salvage score was 61% (51% to 95%). The implant survival and complications resulting from the use of the modular system were comparable to the published series of both custom-made and other modular proximal femoral implants. We conclude that at intermediate follow-up the modular tumour prosthesis for proximal femur replacement provides versatility, a low incidence of implant-related complications and acceptable function for patients with metastatic tumours, pathological fractures and failed fixation of the proximal femur. It also functions as well as a custom-made endoprosthetic replacement.

Peri-acetabular resection and endoprosthetic reconstruction for tumours of the acetabulum

We treated 98 patients with peri-acetabular tumours by resection and reconstruction with a custom-made pelvic endoprosthesis. The overall survival of the patients was 67% at five years, 54% at ten years and 51% at 30 years. One or more complications occurred in 58.1% of patients (54), of which infection was the most common, affecting 30% (28 patients). The rate of local recurrence was 31% (29 patients) after a mean follow-up of 71 months (11 to 147). Dislocation occurred in 20% of patients (19). Before 1996 the rate was 40.5% (17 patients) but this was reduced to 3.9% (two patients) with the introduction of a larger femoral head. There were six cases of palsy of the femoral nerve with recovery in only two. Revision or excision arthroplasty was performed in 23.7% of patients (22), principally for uncontrolled infection or aseptic loosening. Higher rates of death, infection and revision occurred in men. This method of treatment is still associated with high morbidity. Patients should be carefully selected and informed of this pre-operatively.

THE SURGICAL TREATMENT AND OUTCOME OF PATHOLOGICAL FRACTURES IN LOCALISED OSTEOSARCOMA

We reviewed the surgical treatment and oncological results of 40 patients with pathological fractures from localised osteosarcoma of the long bones to determine the outcome of limb salvage in their management. All had had adjuvant chemotherapy. There were 26 males and 14 females with a median age at diagnosis of 18 years (2 to 46) and a median follow-up of 55 months (8 to 175). We performed limb salvage in 27 patients and amputation in 13. The margins of resection were radical in five patients, wide in 26, marginal in six, wide but contaminated in two and intralesional in one. Local recurrence developed in 19% of those treated by limb salvage and in none of those who had an amputation. The cumulative five-year survival of all the patients was 57% and in those treated by limb salvage or amputation it was 64% and 47%, respectively (p > 0.05). Limb-sparing surgery with adequate margins of excision can be achieved in many patients with pathological fractures from primary osteosarcoma without compromising survival, but the risk of local recurrence is significant.

THE OUTCOME AND FUNCTIONAL RESULTS OF DIAPHYSEAL ENDOPROSTHESES AFTER TUMOUR EXCISION

Improvement in the life expectancy of patients with primary bone tumours has led to increased emphasis on limb salvage and preservation of function. Between 1979 and 1994 we used custom-made endoprostheses in 18 patients to reconstruct diaphyseal defects after excision of primary bone tumours. The mean age at operation was 26 years (9 to 64) and the median follow-up 65 months (6 to 188). Fifteen patients have survived and are free from local or metastatic disease. Local recurrence developed in one patient. Using the modified Enneking functional scoring system, 77% of the patients achieved 80% or more of their premorbid functional capability. Mechanical loosening, limb shortening and secondary osteoarthritis were the main complications. There were no infections. We conclude that diaphyseal endoprostheses offer a good clinical and functional outcome in the lower limb.

Retrospective evaluation of the incidence of early periprosthetic infection with silver-treated endoprostheses in high-risk patients

We conducted a case-control study to examine the merit of silver-coated tumour prostheses. We reviewed 85 patients with Agluna-treated (silver-coated) tumour implants treated between 2006 and 2011 and matched them with 85 control patients treated between 2001 and 2011 with identical, but uncoated, tumour prostheses. In all, 106 men and 64 women with a mean age of 42.2 years (18.4 to 90.4) were included in the study. There were 50 primary reconstructions (29.4%); 79 one-stage revisions (46.5%) and 41 two-stage revisions for infection (24.1%). The overall post-operative infection rate of the silver-coated group was 11.8% compared with 22.4% for the control group (p = 0.033, chi-square test). A total of seven of the ten infected prostheses in the silver-coated group were treated successfully with debridement, antibiotics, and implant retention compared with only six of the 19 patients (31.6%) in the control group (p = 0.048, chi-square test). Three patients in the silver-coated group (3.5%) and 13 controls (15.3%) had chronic periprosthetic infection (p = 0.009, chi-square test). The overall success rates in controlling infection by two-stage revision in the silver-coated group was 85% (17/20) compared with 57.1% (12/21) in the control group (p = 0.05, chi-square test). The Agluna-treated endoprostheses were associated with a lower rate of early periprosthetic infection. These silver-treated implants were particularly useful in two-stage revisions for infection and in those patients with incidental positive cultures at the time of implantation of the prosthesis. Debridement with antibiotic treatment and retention of the implant appeared to be more successful with silver-coated implants.