Proximal Tibia Reconstruction After Bone Tumor Resection: Are Survivorship and Outcomes of Endoprosthetic Replacement and Osteoarticular Allograft Similar?

BACKGROUND: The proximal tibia is one of the most challenging anatomic sites for extremity reconstructions after bone tumor resection. Because bone tumors are rare and large case series of reconstructions of the proximal tibia are lacking, we undertook this study to compare two major reconstructive approaches at two large sarcoma centers. QUESTIONS/PURPOSES: The purpose of this study was to compare groups of patients treated with endoprosthetic replacement or osteoarticular allograft reconstruction for proximal tibia bone tumors in terms of (1) limb salvage reconstruction failures and risk of amputation of the limb; (2) causes of failure; and (3) functional results. METHODS: Between 1990 and 2012, two oncologic centers treated 385 patients with proximal tibial resections and reconstruction. During that time, the general indications for those types of reconstruction were proximal tibia malignant tumors or bone destruction with articular surface damage or collapse. Patients who matched the inclusion criteria (age between 15 and 60 years old, diagnosis of a primary bone tumor of the proximal tibia treated with limb salvage surgery and reconstructed with endoprosthetic replacement or osteoarticular allograft) were included for analysis (n = 149). In those groups (endoprosthetic or allograft), of the patients not known to have reached an endpoint (death, reconstructive failure, or limb loss) before 2 years, 85% (88 of 104) and 100% (45 of 45) were available for followup at a minimum of 2 years. A total of 88 patients were included in the endoprosthetic group and 45 patients in the osteoarticular allograft group. Followup was at a mean of 9.5 (SD 6.72) years (range, 2-24 years) for patients with endoprosthetic reconstructions, and 7.4 (SD 5.94) years for patients treated with allografts (range, 2-21 years). The following variables were compared: limb salvage reconstruction failure rates, risk of limb amputation, type of failures according to the Henderson et al. classification, and functional results assessed by the Musculoskeletal Tumor Society system. RESULTS: With the numbers available, after competitive risk analysis, the probability of failure for endoprosthetic replacement of the proximal tibia was 18% (95% confidence interval [CI], 10.75-27.46) at 5 years and 44% (95% CI, 31.67-55.62) at 10 years and for osteoarticular allograft reconstruction was 27% (95% CI, 14.73-40.16) at 5 years and 32% (95% CI, 18.65-46.18) at 10 years. There were no differences in terms of risk of failures at 5 years (p = 0.26) or 10 years (p = 0.20) between the two groups. Fifty-one of 88 patients (58%) with proximal tibia endoprostheses developed a reconstruction failure with mechanical causes being the most prevalent (32 of 51 patients [63%]). A total of 19 of 45 osteoarticular allograft reconstructions failed (42%) and nine of 19 (47%) of them were caused by early infection. Ten-year risk of amputation after failure for endoprosthetic reconstruction was 10% (95% CI, 5.13-18.12) and 11% (95% CI, 4.01-22.28) for osteoarticular allograft with no difference between the groups (p = 0.91). With the numbers available, there were no differences between the groups in terms of the mean Musculoskeletal Tumor Society score (26.58, SD 2.99, range, 19-30 versus 27.52, SD 1.91, range, 22-30; p = 0.13; 95% CI, -2,3 to 0.32). Mean extension lag was more severe in the endoprosthetic group than the osteoarticular allograft group: 13.56° (SD 18.73; range, 0°-80°) versus 2.41° (SD 5.76; range, 0°-30°; p < 0.001; 95% CI, 5.8-16.4). CONCLUSIONS: Reconstruction of the proximal tibia with either endoprosthetic replacement or osteoarticular allograft appears to offer similar reconstruction failures rates. The primary cause of failure for allograft was infection and for endoprosthesis was mechanical complications. We believe that the treating surgeon should have both options available for treatment of patients with malignant or aggressive tumors of the proximal tibia. (S)he might consider an allograft in a younger patient to achieve better extensor mechanism function, whereas in an older patient or one with a poorer prognosis where return to function and ambulation quickly is desired, an endoprosthesis may be advantageous. LEVEL OF EVIDENCE: Level III, therapeutic study.

Management and prognostic significance of pathological fractures through chondrosarcoma of the femur.

PURPOSE: The aim of the study was to report overall survival, local recurrence and development of metastasis in a group of patients with femur chondrosarcoma that presented with or without a pathological fracture. METHODS: A retrospective review was performed, and 182 patients (39 pathological fractures) that had been treated by oncologic surgery for femoral chondrosarcoma were included. The mean age of the series was 50 years (range, eight to 90) and 114 patients were male (63%). Mean follow-up was 113 months (range, three to 216). Cancer-specific overall survival, development of metastasis and local recurrence were analysed, grouping patients by grade (grade I / grade 2-3 / dedifferentiated). RESULTS: Disease-specific survival in the entire group of chondrosarcoma of the femur was 69% (CI95% 63-76) at 5 years. Five-year disease-specific survival in the fracture group was 49% lower than in the control group 75% (p = 0.0001). Survival of patients with grade 1 chondrosarcoma with fracture was significantly less than those without fracture (p = 0.02) but there was no difference in those with grade 2-3 (p = 0.49) and dedifferentiated tumours (p = 0.09). The local recurrence rate of the entire series was 27%. Only dedifferentiated chondrosarcomas with an associated pathological fracture had a significantly higher rate of local recurrence. There was no relationship between development of metastases and fracture. CONCLUSION: A pathological fracture of the femur has a negative prognostic influence in grade 1 chondrosarcoma and increases the risk of local recurrence in dedifferentiated femur chondrosarcomas.

Hoffa's fat pad tumours: what do we know about them?

PURPOSE: We report on a group of patients with tumours in the Hoffa's fat pad (HFP), their clinical presentation, histological type and treatment, including two synovial sarcomas with their clinical follow-up, which have not been described previously in the literature. METHODS: We performed a retrospective review of our prospectively collected database of 25 cases of HFP tumours with at least six months follow-up. RESULTS: The gender, age at presentation (over and under 16 years of age), clinical features, history of trauma, treatment chosen, and complications were recorded. The mean age of the patients was 32 years (three to 47). Six patients were under 16 years old. Pain was the most common symptom, present in 92% (n = 23/25). The final diagnoses included 23 (92%) benign tumours and two (8%) malignant tumours. The most common benign tumour was pigmented villonodular synovitis (PVNS) (48% n = 12). The two malignant tumours were synovial sarcomas and both presented in patients under 16 years old. CONCLUSIONS: Hoffa's fat pad tumours are an uncommon and rarely diagnosed group of lesions that can be misinterpreted as any knee pathology. Although the majority of HFP tumours are benign, malignant tumours should be considered in the differential diagnosis for the paediatric population.

Modular endoprosthetic replacement for metastatic tumours of the proximal femur.

BACKGROUND AND AIMS: Endoprosthetic replacements of the proximal femur are commonly required to treat destructive metastases with either impending or actual pathological fractures at this site. Modular prostheses provide an off the shelf availability and can be adapted to most reconstructive situations for proximal femoral replacements. The aim of this study was to assess the clinical and functional outcomes following modular tumour prosthesis reconstruction of the proximal femur in 100 consecutive patients with metastatic tumours and to compare them with the published results of patients with modular and custom made endoprosthetic replacements. METHODS: 100 consecutive patients who underwent modular tumour prosthetic reconstruction of the proximal femur for metastases using the METS system from 2001 to 2007 were studied. The patient, tumour and treatment factors in relation to overall survival, local control, implant survival and complications were analysed. Functional scores were obtained from surviving patients. RESULTS AND CONCLUSION: There were 45 male and 55 female patients. The mean age was 60.2 years. The indications were metastases. Seventy five patients presented with pathological fracture or with failed fixation and 25 patients were at a high risk of developing a fracture. The mean follow up was 15.9 months [range 0-77]. Three patients died within 2 weeks following surgery. 69 patients have died and 31 are alive. Of the 69 patients who were dead 68 did not need revision surgery indicating that the implant provided single definitive treatment which outlived the patient. There were three dislocations (2/5 with THR and 1/95 with unipolar femoral heads). 6 patients had deep infections. The estimated five year implant survival (Kaplan-Meier analysis) was 83.1% with revision as end point. The mean TESS score was 64% (54%-82%). We conclude that METS modular tumour prosthesis for proximal femur provides versatility; low implant related complications and acceptable function lasting the lifetime of the patients with metastatic tumours of the proximal femur.