Controversies in orthopaedic oncology

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting.

Efficacy of Cal-Cemex as bone substitute for tibial plateau fractures

BACKGROUND

Various factors influence treatment and outcomes in tibial plateau fractures. Bone defects are among them. Many materials have been proposed to address this problem: allograft, bone-cements and various bone substitutes (BSM). Cal-Cemex (β-tricalciophosphate and polymethylmethacrylate) is a new hybrid bi-component BSM. A retrospective multicenter study was conducted based on the clinical experience of three European Hospitals, to demonstrate its clinical effectiveness, versatility and safety.

MATERIALS AND METHODS

From December 2016 to March 2022, 45 displaced tibial plateau fractures were treated with internal fixation and augmentation using Cal-Cemex. The average age was 55.9 years. According to Schatzker classification, we included 13 type II, 24 type III, 3 type V and 4 type VI fractures. The postoperative follow-up (FU) consisted of clinical and radiological examinations at 6 and 12 weeks and 1 year after surgery. A CT scan was performed preoperatively and 1 year after surgery. Full weight bearing was permitted after less than 6 weeks. Clinical data were collected from patient charts, while functional data were evaluated using the Rasmussen knee function score, the KOOS score and the Hospital for Special Surgery knee rating score (HSS), to evaluate the range of motion, axis and functionality of the knee.

RESULTS

The average FU was 42.8 months. CT scans taken at 1 year demonstrated a good surface osteointegration without radiolucent lines or osteolysis with good evidence of interdigitation and even bone ingrowth. At 1-year FU, the mean Rasmussen score was 24.7, the mean KOOS score was 90.7 and the mean HSS was 89.9 and the average full weight-bearing period 34.9. No patients had hardware failure or fracture secondary displacement.

DISCUSSION

Cal-Cemex combines biological features and good mechanical performances. It guarantees biocompatibility and osteoconductivity, although it is not fully reabsorbable; β-tricalciophosphate component gives macro- and microporosity that allow fluids to penetrate inside the material, to stimulate bone ingrowth.

CONCLUSIONS

The study suggests that Cal-Cemex is an option for tibial plateau fractures, where augmentation and support are necessary for early full weight bearing. The absence of major complications, ease of application, the possibility to cut and perforate this material support its extensive use in bone augmentation for trauma cases.

Expandable distal femur megaprosthesis: A European Musculoskeletal Oncology Society study on 299 cases

BACKGROUND AND OBJECTIVES

Expandable distal femur prostheses have become more popular over the last decades, but scientific data is limited.

METHODS

A retrospective study was performed, including cases treated between 1986 and 2019 in 15 European referral centers for bone sarcomas.

RESULTS

A total of 299 cases were included. Average follow-up was 80 months (range, 8-287 months). Mean patient age was 10 years. Most (80%) of the implants were noninvasive growers and a fixed hinge knee was used more often (64%) than a rotating hinge. Most prosthetic designs showed good (>80%) implant survival at 10 years, but repeat surgery was required for 63% of the patients. The most frequent reason for revision procedure was the completion of lengthening potential. Noninvasive expandable implants showed less risk of infection compared to invasive growers (11.8% vs 22.9% at 10 years). No difference in aseptic loosening was found between cemented and uncemented stems.

CONCLUSIONS

This study shows the increasing popularity of expandable distal femur prostheses, with overall good results for function and implant survival. However, repeat surgery is frequently required, especially in patients under the age of 10 years old. Infection is less frequent in noninvasive growers compared to implants that require invasive lengthening procedures.