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.

The clinical outcomes of extracorporeal irradiated and re-implanted cemented autologous bone graft of femoral diaphysis after tumour resection.

PURPOSE: We report the outcome of intercalary resection of the femoral diaphysis and extracorporeal irradiated autologous bone graft reconstruction, without the use of vascularized fibular graft. METHODS: Six patients with Ewing sarcoma of the mid-shaft femur who were treated by limb sparing tumour resection and reconstruction with extracorporeal irradiated autologous bone graft with intramedullary cement between 2002 and 2010 were studied. RESULTS: Mean age at the time of surgery was ten years (range, four-23). The length of resected femoral bone averaged 23 cm (15-32 cm). The ratio of bone resection length to total femoral length averaged 60 % (56-66 %). The patients had been followed up for between 16 and 79 months (mean, 41 months) at the time of the study. There was no infection nor fracture in this series. Primary union of the distal and proximal osteotomy sites was achieved in three patients. Delayed union of the proximal osteotomy site occurred in one patient that was successfully treated with iliac crest bone grafting. One patient developed non-union at the distal osteotomy site which failed to heal with bone grafting and was therefore converted to endoprosthetic replacement, and another patient was converted to rotationplasty at five months post-surgery because of contaminated margins. Function was excellent in all patients with surviving re-implanted bone. Local recurrence arose in one patient. CONCLUSION: Our experience suggests that cement augmentation of extracorporeal irradiated and re-implanted bone autografts offer a useful method of reconstructing large femoral diaphyseal bone defects after excision of primary malignant bone tumours.

Bone defects following curettage do not necessarily need augmentation.

BACKGROUND AND PURPOSE: The natural pattern of bone healing in large bony defects following curettage alone as treatment of benign bone tumors around the knee is not well reported. We analyzed the outcome in 146 patients. PATIENTS AND METHODS: 146 patients with over 18 months of follow-up who underwent curettage without bone substitute filling or bone grafting for a benign tumor in the distal femur or upper tibia were included. The mean diameter of the defects following curettage was 5.7 (1.3-11) cm and the estimated average volume was 63 (1-240) cm(3). The plain radiographs before and following curettage were reviewed to establish the size of the initial defect and the rate of reconstitution and infilling of the bone. The time to full weight bearing and any complications were recorded. RESULTS: There was a variable rate of infilling; some defects completely reconstituted to a normal appearance while some never filled in. In 88% of the cases, no further intervention after curettage was required and the mean time to full weight bearing was 6 weeks. The risk of subsequent fracture or the late development of osteoarthritis was strongly related to the size of the cyst at diagnosis, with cysts of > 60 cm(3) (about 5 cm in diameter) having a much higher incidence of complications. INTERPRETATION: This study demonstrates the natural healing ability of bone without any adjuvant filling. It could be used as a baseline for future studies using any sort of filling with autograft, allograft, or bone substitute.

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.

Replacement of the hip in children with a tumor in the proximal part of the femur.

BACKGROUND: Children rarely require hip replacement, and therefore very little is known about the most effective procedure for children who require hip replacement after proximal femoral resection for a tumor. METHODS: We reviewed the outcome of forty hip replacements in children between two and fifteen years old who had a proximal femoral replacement for malignant disease. Twenty-one children survived the illness and were followed for three to twenty-one years. Cemented acetabular components were used initially to restore hip function, but, in more recent procedures, unipolar replacements and uncemented implants were used. RESULTS: Children who were over the age of eleven years at the time of surgery had a rate of failure (defined as revision of the acetabular component) of 25% at ten years compared with a rate of 75% in younger children. Unipolar replacements in children of all ages failed by ten years, either because of pain or subluxation that led to revision. In children over the age of eleven years, both cemented and uncemented acetabular implants performed well. CONCLUSIONS: The preferred method for restoration of hip function in children under the age of eleven years following proximal femoral resection for a tumor remains unclear. We recommend that at the initial hip surgery an attempt should be made to cause as little damage as possible to the acetabulum, but most children will inevitably need revision surgery as they get older. We hope that this study will guide others in their decision-making with regard to this relatively rare condition.

Adult head and neck soft tissue sarcomas: treatment and outcome.

We have retrospectively analysed the experience of a musculoskeletal oncological unit in the management of adult head and neck soft tissue sarcomas from 1990 to 2005. Thirty-six patients were seen, of whom 24 were treated at this unit, the remainder only receiving advice. The median age of the patients was 46 years. Most of the sarcomas were deep and of high or intermediate grade with a median size of 5.5 cm. Eleven different histological subtypes were identified. Wide excision was possible only in 21% of the cases. 42% of the patients developed local recurrence and 42% developed metastatic disease usually in the lungs. Overall survival was 49% at 5 years. Tumour size was the most important prognostic factor. Adult head and neck soft tissue sarcomas have a high mortality rate with a high risk of local recurrence and metastatic disease. The rarity of the disease would suggest that centralisation of care could lead to increased expertise and better outcomes.

Pre- and post-chemotherapy alkaline phosphatase levels as prognostic indicators in adults with localised osteosarcoma.

The prognostic value of alkaline phosphatase (AP) measured before and after chemotherapy, but before surgery was established in a retrospective survey of patients. The patients were 18 years or older, with non-metastatic high-grade osteosarcoma. Pre-chemotherapy AP was available in 89 cases, post-chemotherapy AP in 86 patients, and both in 71 cases. AP was classified as Normal (< 100% upper limit), High (100% < or = AP < 200%) or Very High (AP > or = 200%). Osteosarcoma subtype was predominantly conventional. No correlation was found between subtype and chemotherapy response, local recurrence or survival. Pre-chemotherapy AP was raised more in the osteoblastic subtype. Post-chemotherapy AP and normalisation were the same among different subtypes. AP was not correlated with local recurrence. Normal or High pre-chemotherapy AP correlated with better survival at 10 years (64% and 70%) than Very High pre-chemotherapy AP (37%, P = 0.005). Post-chemotherapy AP correlated with survival (68%, 39% and 25% in the Normal, High and Very High group, P = 0.0007) and response to chemotherapy (P = 0.049). A pre-chemotherapy AP above twice Normal correlated with worse survival. If AP decreased after chemotherapy, but was still raised, survival was better, but still worse than if AP normalised. A raised post-chemotherapy AP predicts poor chemotherapy response.

Change in histological grade in locally recurrent soft tissue sarcomas.

Histological examination of locally recurrent soft tissue sarcomas usually reveals an appearance similar to that of the original tumour. Occasionally, however, recurrent sarcomas appear more or less malignant histologically than the initial lesion. The goals of this paper were to identify the frequency with which this phenomenon occurs, factors that predict for a change in grade and to determine if this change is associated with a different prognosis from other patients with local recurrence. From a large sarcoma database, 124 patients with local recurrence were identified. These patients were distributed into groups who had no change in histological grade, increased histological grade or decreased histological grade on local recurrence. Increased grade occurred approximately 20% of the time, whereas decreased grade occurred in 7% of cases. A histological diagnosis of myxofibrosarcoma was predictive of an increase in histological grade on local recurrence. An increase in histological grade with local recurrence was not associated with a poorer survival.

FUS/ERG gene fusions in Ewing's tumors.

Ewing's tumors are rare pediatric neoplasms that are characterized by specific chromosomal translocations and gene rearrangements. All of the fusion genes reported to date in Ewing's tumors juxtapose the EWS gene at 22q12 to an ETS-related gene, the most common of which are FLI1 at 11q24 and ERG at 21q22. We present here four cases of Ewing's tumor, which showed no evidence of a EWS gene rearrangement, but instead contained translocations involving 16p11 and 21q22. A rearrangement involving the same chromosome bands, t(16;21)(p11;q22), is found in rare cases of acute myeloid leukemia and fuses the FUS gene at 16p11 to the ERG gene at 21q22. In two of our Ewing's tumor cases, we were able to show at the sequence level that the translocation between chromosomes 16 and 21 similarly results in a FUS/ERG fusion. In one case, exons 1-5 and most of exon 6 of FUS were fused in-frame to exon 9 of ERG; in the other case, FUS exons 1-7 were fused in-frame to ERG exons 8-9. The functional fusion transcript is expected to be expressed from the der(21)t(16;21) derivative. In the two other t(16;21)-positive Ewing's cases, we performed bacterial artificial chromosome fluorescence in situ hybridization analysis on metaphases and interphase nuclei to demonstrate colocalization of bacterial artificial chromosomes containing FUS and ERG genes, also highly suggestive of fusion gene formation. These represent the first four cases where FUS, rather than EWS, is rearranged with an ETS-family transcription factor in Ewing's tumors. Our data provide additional evidence that the transactivation domains of the TET family of RNA-binding proteins (such as EWS and FUS) are interchangeable, and suggests a novel mechanism of oncogenesis in Ewing's tumors.

Extensible endoprostheses for bone tumors of the proximal femur in children.

Between 1983 and 1996, nine children were treated with extensible endoprosthetic replacements of the proximal femur after resection of primary bone tumors. Four patients died of their disease. The remaining five patients were observed for an average follow-up period of 7.6 years. In these five patients, the authors performed an average of 10.2 operations per patient, including five lengthenings and a mean total extension of 69.7 mm per patient. Acetabular loosening and hip dislocations were the most frequent complications. Only two patients have not had a revision or a major complication. Despite this, four children are alive with a functioning lower limb and a mean Musculoskeletal Tumor Society functional score of 77.6%. Extensible endoprosthesis of the proximal femur is a viable alternative to hip disarticulation and in selected children offers an opportunity for near-normal development of the lower limb by allowing equalization of limb length and the ability to walk without the use of mobility aids.

Two-stage revision for infected endoprostheses used in tumor surgery.

Thirty-four patients with infected massive endoprostheses had two-stage revision procedures to cure the infection and retain a useful functioning limb. An antibiotic impregnated cement spacer constructed with two cement gun liners and a Kuntscher nail provided temporary stability and also allowed a high dose of local antibiotic concentration. In three patients the infection never was controlled, and one of these patients had a successful second revision surgery. Six other patients had reinfection varying from 14 to 92 months after surgery. Risk factors for reinfection were previous radiotherapy and any additional operative intervention. The overall success rate for controlling infection was 91% at 1 year and 74% at 5 years. Six patients required amputation. The mean functional outcome for the retained limbs using the Musculoskeletal Tumor Society scoring system was 77%. Two-stage revisions seem almost as effective at controlling infection in massive endoprostheses as in conventional joint replacements, particularly if additional surgical interventions can be avoided.

Periosteal Osteosarcoma: A Review of 17 Cases with Mean Follow-up of 52 Months.

PURPOSE: Periosteal osteosarcomas are rare cartilage-rich bone tumours characterized by a juxtacortical eccentric position and are normally regarded oncologically as of intermediate to high grade.Their low incidence is mirrored by a small number of reported cases in the world literature. While there is general agreement that wide surgical excision is required, there is a paucity of evidence regarding adjuvant therapy. Previous reports have not indicated any consistent approach to this to allow appraisal. PATIENTS AND METHODS: We report 17 cases treated at our centre over 16 years. Our policy was to use chemotherapy when the tumour showed any features of high grade. RESULTS: To date, no deaths have resulted from recurrence or metastasis of the tumour although there have been two deaths from other causes. DISCUSSION: Comparison of survival with existing studies is made to draw conclusions regarding future treatment of this condition in terms of surgical and adjuvant approaches.