Elisa Pala

Failure Mode Classification for Tumor Endoprostheses: Retrospective Review of Five Institutions and a Literature Review

BACKGROUND Massive endoprostheses provide orthopaedic oncologists with many reconstructive options after tumor resection, although failure rates are high. Because the number of these procedures is limited, failure of these devices has not been studied or classified adequately. This investigation is a multicenter review of the use of segmental endoprostheses with a focus on the modes, frequency, and timing of failure. METHODS Retrospective reviews of the operative databases of five institutions identified 2174 skeletally mature patients who received a large endoprosthesis for tumor resection. Patients who had failure of the endoprosthesis were identified, and the etiology and timing of failure were noted. Similar failures were tabulated and classified on the basis of the risk of amputation and urgency of treatment. Statistical analysis was performed to identify dependent relationships among mode of failure, anatomic location, and failure timing. A literature review was performed, and similar analyses were done for these data. RESULTS Five hundred and thirty-four failures were identified. Five modes of failure were identified and classified: soft-tissue failures (Type 1), aseptic loosening (Type 2), structural failures (Type 3), infection (Type 4), and tumor progression (Type 5). The most common mode of failure in this series was infection; in the literature, it was aseptic loosening. Statistical dependence was found between anatomic location and mode of failure and between mode of failure and time to failure. Significant differences were found in the incidence of failure mode Types 1, 2, 3, and 4 when polyaxial and uniaxial joints were compared. Significant dependence was also found between failure mode and anatomic location in the literature data. CONCLUSIONS There are five primary modes of endoprosthetic failure, and their relative incidences are significantly different and dependent on anatomic location. Mode of failure and time to failure also show a significant dependence. Because of these relationships, cumulative reporting of segmental failures should be avoided because anatomy-specific trends will be missed. Endoprosthetic design improvements should address failure modes specific to the anatomic location.

Clinical outcome of central conventional chondrosarcoma

Aim of this study was to analyze (1) survival, local recurrence (LR), and metastasis rates between the three histological tumor grades; (2) whether type of treatment and tumor site influenced prognosis for each histologic grade.

Survival of current production tumor endoprostheses: Complications, functional results, and a comparative statistical analysis

Retrospectively analyze outcomes of current‐generation Global Modular Replacement System (GMRS) modular tumor endoprosthesis for the lower limb in primary and secondary implantation procedures.

Advances in Segmental Endoprosthetic Reconstruction for Extremity Tumors: A Review of Contemporary Designs and Techniques

BACKGROUND Improved understanding and advances in treatment regimens have led to increased longevity among patients diagnosed with extremity soft tissue sarcomas. Limb salvage techniques and implants have improved and continue to evolve to accommodate the increasing demands and survival of these patients. METHODS The current report is a review of the literature for recent advancements in techniques, implant design, and outcomes in the field of limb salvage therapy using segmental megaprostheses for the treatment of extremity sarcomas. We report on our experience in this field utilizing a classification system of failure mechanisms to outline to discuss current controversies in management. RESULTS Five mechanisms of failure have been identified: soft-tissue failure, aseptic loosening, structural failure, infection, and tumor progression. Infection was the most common mode of failure in our series, accounting for 34% of cases. Soft-tissue failure occurred most commonly in the joints that depend heavily on periarticular muscles and ligaments for stability due to their high degree of functional range of motion. We observed a 28% soft-tissue failure rate about the shoulder and hip, aseptic loosening accounted for 19% of implant failures, and structural failure was seen in 17% of cases. Seventeen percent of cases failed due to tumor progression, an etiology that is defined by biological factors, surgical technique, and adjuvant therapies. CONCLUSIONS Surgical techniques and megaprosthesis designs are constantly changing in order to meet the challenge of increasing functional demands and longevity in this unique patient population. A classification system defined by treatment failure etiologies provides the framework for discussion of current controversies in limb salvage therapy as well as a guide for advancement and potential solutions in this challenging arena.

Protocol of surgical treatment of long bone pathological fractures

Long bone pathological fractures in patients with primary and metastatic bone tumours are difficult to treat and their management may alter the prognosis of the disease and jeopardize survival. The aim of this article was to review the relevant studies reporting on the management of tumour patients with pathological fractures of the long bones, to discuss the most suitable approach in these patients, to highlight specific treatment recommendations, and finally based on this analysis and our clinical practice, to propose a treatment algorithm for decision making and treatment.

Outcome of expandable prostheses in children.

Background: Expandable prostheses offer the advantages of limb-salvage and limb-length equality at skeletal maturity. However, what is the cost for achieving that goal, and in how many children this is achieved? Materials and Methods: We present 32 children (16 boys and 16 girls; mean age, 9 y) with bone sarcomas of the femur treated with limb salvage using expandable prostheses. The Kotz Growing prosthesis and the noninvasive Repiphysis and Stanmore expandable prostheses were used. The mean follow-up was 49 months. Survival analysis of the children and primary implants and functional evaluation were performed. Results: Survival of the children was 94% and 84% at 48 and 72 months. Survival of the primary prostheses was 78% and 66% at 48 and 72 months; survival was significantly higher only for the Kotz when compared with the Repiphysis prostheses (P=0.026). The rate of implant-related complications was 51.3%; 9 prostheses (23%) were revised because of aseptic loosening, infection, and breakage. A mean total lengthening of 28 mm (4 to 165 mm) was achieved by 84 procedures (2.6 procedures/patient). Three of the 9 children who reached skeletal maturity had limb-length equality and 6 discrepancy of 15 to 30 mm. The mean Musculoskeletal Tumor Society score was excellent (79%) without a significant difference between the type of prostheses (P=0.934). Conclusions: The Kotz Growing prosthesis, although it requires an open lengthening procedure, has shown higher survival when compared with the noninvasive Repiphysis prosthesis. However, the total lengthening remains small, and the complications rates are high even with the noninvasive prostheses.

Infections in surgery of primary tumors of the sacrum.

Study Design. Retrospective case series. Objective. To evaluate the risk of infection, related treatment, and outcome after surgery of the 2 most common primary sacral tumors. Summary of Background Data. Rarity of sacral tumors has limited the number of population-based studies. Treatment depends on malignancy or local aggressiveness: wide resection is indicated for malignant lesions, intralesional surgery for benign. Methods. We studied 82 patients with sacral chordomas (55 cases) or giant cell tumor (GCT) (27 cases) treated between 1976 and 2005. All patients had IV antibiotic therapy with amikacin and teicoplanin. Surgery of chordoma was resection; surgery of GCT was intralesional excision. Infections were classified as immediate postoperative, early (within 6 months), and late (more than 6 months from surgery). Mean follow-up was 9.5 years (range: 3–27 years). Some factors possibly influencing the risk of infection were statistically analyzed by Kaplan Meier curves and log-rank test. Results. No deep infections were observed in the GCT series. Three patients with sacral chordoma died for postoperative complications and were excluded from this analysis. Of the remaining 52 patients with chordoma, 23/52 had deep wound infection (44%) that required 1 or more surgical debridements combined with antibiotics, according to cultures. In 16 patients (70%), infection occurred within 4 weeks postoperatively, and in 7 within 6 months. Most frequent bacteria were Enterococcus (23%), Escherichia coli (20%), and Pseudomonas aeruginosa (18%). In 74% of cases, infection was multimicrobial. Level of resection, previous intralesional treatment elsewhere, tumor volume, and age did not statistically influence risk of infection. Conclusion. Type of surgery was the prominent factor related to a major risk of infection. Operating procedure time correlated as well. Resections of sacral chordoma imply a high risk of deep infection, while intralesional excision of GCT does not. All infections healed with surgical debridements and antibiotic therapy.

Post-Radiation Sarcomas. Clinical Outcome of 52 Patients

Previous studies reported on post‐radiation sarcomas. However, the incidence, latency from radiation therapy, treatment, and survival has been difficult to evaluate. We performed a retrospective, single‐institutional study to determine these factors for post‐radiation sarcomas.

Prognostic factors in surgical resection of sacral chordoma

The best treatment of sacral chordoma is surgical resection, nowadays associated with optimized radiation therapy. We analysed 1) the oncologic outcome in a large series; 2) the effect of previous intralesional surgery, resection level, tumor volume and margins on survivorship to local recurrence (LR) and 3) the complication rate.

Proximal tibial resections and reconstructions: clinical outcome of 225 patients.

Previous studies reported variable outcome of proximal tibial resections and reconstructions. Therefore, we evaluated the survival, Musculoskeletal Tumor Society (MSTS) function, and complications of patients and reconstructions in this location.