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.

Transcutaneous Oximetry Does Not Reliably Predict Wound-healing Complications in Preoperatively Radiated Soft Tissue Sarcoma

BACKGROUND

Surgical wound-healing complications after tumor resections in tissue that has been preoperatively radiated are a major clinical problem. Most studies have reported that complications occur in more than 30% of patients undergoing such resections in the lower extremity. There is currently no available method to predict which patients are likely to have a complication. Transcutaneous oximetry has been identified in preliminary studies as potentially useful, but the available evidence on its efficacy for this application thus far is inconclusive.

QUESTIONS/PURPOSES

(1) Does transcutaneous oximetry measurement below 25 mmHg at any location in the surgical wound bed predict a wound-healing complication? (2) Does recovery (increase) in transcutaneous oxygen measurement during the rest period between the end of radiation and the time of surgery protect against wound-healing complications?

METHODS

A prospective, multi-institution study was coordinated to measure skin oxygenation at three timepoints in patients undergoing surgery for a lower extremity soft tissue sarcoma after preoperative radiation. Between 2016 and 2020, the five participating centers treated 476 patients for lower extremity soft tissue sarcoma. Of those, we considered those with a first-time sarcoma treated with radiation before limb salvage surgery as potentially eligible. Based on that, 21% (98 of 476) were eligible; a further 12% (56 of 476) were excluded because they refused to participate or ultimately, they were treated with a flap, amputation, or skin graft. Another 1% (3 of 476) of patients were lost because of incomplete datasets or follow-up less than 6 months, leaving 8% (39 of 476) for analysis here. The mean patient age was 62 ± 14 years, 62% (24 of 39) of the group were men, and 18% (7 of 39) of patients smoked cigarettes; 87% (34 of 39) of tumors were intermediate/high grade, and the most common histologic subtype was undifferentiated pleomorphic sarcoma. In investigating complications, a cutoff of 25 mmHg was chosen based on a pilot investigation that identified this value. All patients were assessed for surgical wound-healing complications, which were defined as: those resulting in a return to the operating room, initiation of oral or IV antibiotics, intervention for seroma, or prolonged wound packing or dressing changes. To answer the first research question, we compared the proportion of patients who developed a wound-healing complication between those patients who had any reading below 25 mmHg (7 of 39) and those who did not (32 of 39). To answer the second question, we compared the group with stable or decreased skin oxygenation (22 of 37 patient measurements [two patients missed the immediate postoperative measurement]) to the group that had increased skin oxygen measurement (15 of 37 measurements) during the period between the end of radiation and the surgical procedure; again, the endpoint was the development of a wound-healing complication. This study was powered a priori to detect an unadjusted odds ratio for wound-healing complications as small as 0.71 for a five-unit (5 mmHg) increase in TcO 2 between the groups, with α set to 0.05, β set to 0.2, and a sample size of 40 patients.

RESULTS

We found no difference in the odds of a wound-healing complication between patients whose transcutaneous oxygen measurements were greater than or equal to 25 mmHg at all timepoints compared with those who had one or more readings below that threshold (odds ratio 0.27 [95% confidence interval (CI) 0.05 to 1.63]; p = 0.15). There was no difference in the odds of a wound-healing complication between patients who had recovery of skin oxygenation between radiation and surgery and those who did not (OR 0.63 [95% CI 0.37 to 5.12]; p = 0.64).

CONCLUSION

Transcutaneous oximetry cannot be considered a reliable test in isolation to predict wound-healing complications. This may be a function of the fact that transcutaneous oximetry samples a relatively small portion of the landscape in which a wound-healing complication could potentially arise. In the absence of a reliable diagnostic test, clinicians must still use their best judgment regarding surgical timing and work to address modifiable risk factors to avoid complications. The unanswered question that remains is whether there is a skin perfusion or oxygenation issue at the root of these complications, which seems likely. Alternative approaches that can assess the wound more broadly and in real time, such as fluorescent probes, may be deserving of further investigation.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Neoadjuvant Chemotherapy and Endoprosthetic Reconstruction for Lower Extremity Sarcomas: Does Timing Impact Complication Rates?

INTRODUCTION

Sarcoma patients undergoing surgical resection and endoprosthetic reconstruction often receive neoadjuvant chemotherapy (NACT). The objective of the current study was to determine if the timing of NACT impacts the rates of surgical site infections (SSI) and reoperations.

METHODS

This study was a secondary analysis of the recently published Prophylactic Antibiotic Regimens in Tumor Surgery trial. Patients who underwent NACT, tumor resection, and endoprosthetic reconstruction for a bone or soft tissue sarcoma were included. Multivariate Cox proportional hazards regression models were created to evaluate if NACT timing was predictive of SSI or reoperations.

RESULTS

Overall, 216 patients from 39 clinical sites were included in the analysis. The most common diagnosis was osteosarcoma (75%), followed by Ewing's sarcoma (16%). The median time from completion of NACT to surgery was 24 days (interquartile range 15-42 days). Eighty-five (39%) patients underwent surgery within 3 weeks of completing NACT, 78 (36%) underwent surgery 3-6 weeks after completing NACT, and 53 (22%) patients underwent surgery > 6 weeks after completion of NACT. The timing of NACT did not impact SSI rates or reoperation rates. Longer operative time was an independent predictor of both SSI [hazard ratio (HR) per hour of 1.21, 95% confidence interval (CI) 1.07-1.40; p = 0.002] and reoperation rates (HR of 1.15 per hour, 95% CI 1.03-1.28; p = 0.014).

CONCLUSION

The timing of surgery following NACT varied considerably. Chemotherapy timing did not impact SSI or reoperations in patients undergoing surgical resection and endoprosthetic reconstruction in sarcoma patients.

Complex Reconstruction for Acetabular Pathologic Fracture in Unusual Chondroblastoma With Aneurysmal Bone Cyst

Treating bone loss with complex arthroplasty poses a significant challenge for the arthroplasty surgeon. When considering a reconstructive case after pathologic fracture and oncologic excision, a multidisciplinary approach with reliance on arthroplasty principles is critical. An 18-year-old patient presented with a complex acetabular pathologic fracture through a chondroblastoma with a secondary aneurysmal bone cyst. An outside institution performed a biopsy and placed a hip-spanning external fixator. Multidisciplinary planning led to tumor excision, complex acetabular arthroplasty reconstruction including structural bone grafting, and internal fixation. At the third year of follow-up, there was no evidence of mechanical loosening of the hip arthroplasty, reoperation, or tumor recurrence. The structural graft was completely osseointegrated, confirmed by a computed tomography scan obtained at 2 years postoperatively. This report demonstrates an unusual location of chondroblastoma, presenting with acetabular fracture definitively treated with complex multidisciplinary reconstruction leading to an excellent outcome in a young patient.

A retrospective review of revision proximal humeral allograft-prosthetic composite procedures: an analysis of proximal humeral bone stock restoration

BACKGROUND

Allograft-prosthetic composite (APC) reconstruction of the proximal humerus is a technique for reconstruction of large bone deficits, provides improvement in pain and function, and is thought to restore bone if revision surgery is needed. The purpose of this study was to evaluate the ability of proximal humeral APCs to restore usable bone at the time of revision surgery.

METHODS

Two institutional electronic medical records were reviewed to evaluate proximal humeral APC procedures performed between 1970 and 2018. We identified 115 cases, of which 14 underwent revision for aseptic causes. The indications for revision included nonunion (n = 7), glenohumeral instability (n = 5), and allograft fracture (n = 2). Three categories were used to classify the amount of usable allograft retained at revision surgery: type A, complete allograft retention; type B, partial retention; and type C, no retention.

RESULTS

A total of 14 patients (6 male and 8 female patients) underwent revision of the APC reconstruction at a mean of 22.8 months. At revision, allograft retention was classified as type A in 6 shoulders, type B in 3, and type C in 5. Type A cases were associated with nonunion with a well-fixed stem, type B cases were associated with instability and were converted from a hemiarthroplasty to a reverse total shoulder arthroplasty, and type C cases were associated with an allograft fracture or nonunion with a loose humeral component.

CONCLUSION

A substantial number of revisions of proximal humeral APC reconstructions maintain a portion of the allograft bone (64.3%). This study supports the ongoing use of the APC reconstruction technique for large bone deficits.

Pediatric Sarcoma Patients with Worse Physical Function but Better Peer Relationships and Depressive Symptoms than U.S. Pediatric Population as Measured by PROMIS®

Background

Pediatric patients with sarcomas are at risk of poor quality of life outcomes. The National Institutes of Health (NIH)-funded Patient-reported Outcomes Measurement Information System (PROMIS®) improves our ability to capture patient-reported outcomes. Do physical function, social, and mental health PROMIS outcomes for pediatric patients with non-metastatic malignant sarcomas differ from the U.S. pediatric population?

Methods

Six pediatric PROMIS short forms were collected for patient visits to orthopedic oncology at a tertiary referral center from September 1, 2016, to March 31, 2017. Mean T-scores differed from the reference population by a one-sample t-test.

Results

Of the 30 eligible patients, five had soft-tissue sarcomas and 25 (83%) had bone sarcomas. The mean age of the cohort was 13 years (5-17). The study cohort had a mean physical function T-score of 39.8 (SD 9.8), which was worse than the reference population. In contrast, the mean peer relationship T-score of 54.3 (SD 8.8) and mean depression T-score of 42.0 (SD 9.1) were better than the reference population.

Conclusions

Pediatric patients with non-metastatic sarcomas had a worse physical function but a better peer relationship and depression scores than the U.S. PROMIS reference population. Ceiling and flooring effects were reported. The level of evidence was III.

Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study

Objectives

As tumours of bone and soft tissue are rare, multicentre prospective collaboration is essential for meaningful research and evidence-based advances in patient care. The aim of this study was to identify barriers and facilitators encountered in large-scale collaborative research by orthopaedic oncological surgeons involved or interested in prospective multicentre collaboration.

Methods

All surgeons who were involved, or had expressed an interest, in the ongoing Prophylactic Antibiotic Regimens in Tumour Surgery (PARITY) trial were invited to participate in a focus group to discuss their experiences with collaborative research in this area. The discussion was digitally recorded, transcribed and anonymised. The transcript was analysed qualitatively, using an analytic approach which aims to organise the data in the language of the participants with little theoretical interpretation.

Results

The 13 surgeons who participated in the discussion represented orthopaedic oncology practices from seven countries (Argentina, Brazil, Italy, Spain, Denmark, United States and Canada). Four categories and associated themes emerged from the discussion: the need for collaboration in the field of orthopaedic oncology due to the rarity of the tumours and the need for high level evidence to guide treatment; motivational factors for participating in collaborative research including establishing proof of principle, learning opportunity, answering a relevant research question and being part of a collaborative research community; barriers to participation including funding, personal barriers, institutional barriers, trial barriers, and administrative barriers and facilitators for participation including institutional facilitators, leadership, authorship, trial set-up, and the support of centralised study coordination.

Conclusions

Orthopaedic surgeons involved in an ongoing international randomised controlled trial (RCT) were motivated by many factors to participate. There were a number of barriers to and facilitators for their participation. There was a collective sense of fatigue experienced in overcoming these barriers, which was mirrored by a strong collective sense of the importance of, and need for, collaborative research in this field. The experiences were described as essential educational first steps to advance collaborative studies in this area. Knowledge gained from this study will inform the development of future large-scale collaborative research projects in orthopaedic oncology.

Cite this article: J. S. Rendon, M. Swinton, N. Bernthal, M. Boffano, T. Damron, N. Evaniew, P. Ferguson, M. Galli Serra, W. Hettwer, P. McKay, B. Miller, L. Nystrom, W. Parizzia, P. Schneider, A. Spiguel, R. Vélez, K. Weiss, J. P. Zumárraga, M. Ghert. Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study. Bone Joint Res 2017;6:–314. DOI: 10.1302/2046-3758.65.BJR-2016-0192.R1.