Benjamin Deheshi

Prophylactic antibiotic regimens in tumour surgery (PARITY): protocol for a multicentre randomised controlled study

Introduction Limb salvage with endoprosthetic reconstruction is the standard of care for the management of lower-extremity bone tumours in skeletally mature patients. The risk of deep postoperative infection in these procedures is high and the outcomes can be devastating. The most effective prophylactic antibiotic regimen remains unknown, and current clinical practice is highly varied. This trial will evaluate the effect of varying postoperative prophylactic antibiotic regimens on the incidence of deep infection following surgical excision and endoprosthetic reconstruction of lower-extremity bone tumours. Methods and analysis This is a multicentre, blinded, randomised controlled trial, using a parallel two-arm design. 920 patients 15 years of age or older from 12 tertiary care centres across Canada and the USA who are undergoing surgical excision and endoprosthetic reconstruction of a primary bone tumour will receive either short (24 h) or long (5 days) duration postoperative antibiotics. Exclusion criteria include prior surgery or infection within the planned operative field, known colonisation with methicillin-resistant Staphylococcus aureus or vancomycin-resistant Enterococcus at enrolment, or allergy to the study antibiotics. The primary outcome will be rates of deep postoperative infections in each arm. Secondary outcomes will include type and frequency of antibiotic-related adverse events, patient functional outcomes and quality-of-life scores, reoperation and mortality. Randomisation will be blocked, with block sizes known only to the methods centre responsible for randomisation, and stratified by location of tumour and study centre. Patients, care givers and a Central Adjudication Committee will be blinded to treatment allocation. The analysis to compare groups will be performed using Cox regression and log-rank tests to compare survival functions at α=0.05. Ethics and dissemination This study has ethics approval from the McMaster University/Hamilton Health Sciences Research Ethics Board (REB# 12-009). Successful completion will significantly impact on clinical practice and enhance patients’ lives. More broadly, this trial will develop a network of collaboration from which further high-quality trials in Orthopaedic Oncology will follow.

Use of a calcium sulfate-calcium phosphate synthetic bone graft composite in the surgical management of primary bone tumors.

Benign primary bone tumors are commonly treated with intralesional curettage with or without the use of surgical adjuvants. The reconstructive approach to the resulting contained bone defects is controversial, and clinical practice is varied. Synthetic bone substitutes may provide early mechanical support while minimizing the risks of disease transmission, nonunion, infection, and donor-site morbidity. Limited data exists regarding the use of calcium sulfate-calcium phosphate composite bone substitute for this purpose. The authors retrospectively reviewed the clinical outcomes of 24 patients with benign primary bone tumors who underwent intralesional curettage followed by reconstruction with a calcium sulfate-calcium phosphate composite bone substitute. Mean follow-up was 23 months. The most common diagnosis was giant cell tumor of bone. Six patients had upper-extremity tumors and 18 had lower-extremity tumors. Mean preoperative radiographic tumor volume was 41.0 cm(3). Mean volume of PRO-DENSE (Wright Medical Technology, Arlington, Tennessee) used in each patient was 15.6 cm(3). Mean time to full weight bearing for all patients was 7.3 weeks. Two patients sustained local tumor recurrences. No postoperative fractures occurred, and no complications occurred related to the use of the calcium sulfate-calcium phosphate composite. One case of deep infection occurred secondary to wound breakdown. The use of a calcium sulfate-calcium phosphate composite was associated with rapid biological integration and an early return to activities of daily living, with no composite-related complications. This technique is a viable option in the reconstruction of cavitary bone defects following intralesional curettage of primary benign bone tumors.

Prophylactic antibiotic regimens in tumor surgery (PARITY) survey

BackgroundDeep infection following endoprosthetic limb reconstruction for sarcoma of the long bones is a devastating complication occurring in 15% of sarcoma patients. Optimizing infection protocols and conducting definitive surgical trials are critical to improving outcomes. In this study, the PARITY (P rophylactic A ntibiotic R egimens i n T umor Surgery) investigators aimed to examine surgeon preferences in antibiotic prophylaxis and perceptions about current evidence, as well as to ascertain interest in resolving uncertainty in the evidence with clinical trials.MethodsWe used a cross-sectional survey to examine current practice in the prescription of prophylactic antibiotics in Musculoskeletal Tumor Surgery. The survey was approved by our institution’s Ethics Board and emailed to all Active Members of the Musculoskeletal Tumor Society (MSTS) and Canadian Orthopaedic Oncology Society (CANOOS). Survey answers were collected using an anonymous online survey tool.ResultsOf the 96 surgeons who received the questionnaire, 72 responded (75% response rate (% CI: 65.5, 82.5%)). While almost all respondents agreed antibiotic regimens were important in reducing the risk of infection, respondents varied considerably in their choices of antibiotic regimens and dosages. Although 73% (95% CI: 61, 82%) of respondents prescribe a first generation cephalosporin, 25% favor additional coverage with an aminoglycoside and/or Vancomycin. Of those who prescribe a cephalosporin, 33% prescribe a dosage of one gram for all patients and the reminder prescribe up to 2 grams based on body weight. One in three surgeons (95% CI: 25, 48%) believes antibiotics could be discontinued after 24 hours but 40% (95% CI: 30, 53%) continue antibiotics until the suction drain is removed. Given the ongoing uncertainty in evidence to guide best practices, 90% (95% CI: 81, 95%) of respondents agreed that they would change their practice if a large randomized controlled trial showed clear benefit of an antibiotic drug regimen different from what they are currently using. Further support for a clinical trial was observed by an overwhelming surgeon interest (87%; 95% CI: 77, 93%) in participating in a multi-center randomized controlled study.ConclusionThe current lack of guidelines for the prescription of prophylactic antibiotics in Musculoskeletal Tumor Surgery has left Orthopaedic Oncologists with varying opinions and practices. The lack of current evidence and strong surgeon support for participating in a definitive study provides strong rationale for clinical trials.

Patient-oriented functional results of total femoral endoprosthetic reconstruction following oncologic resection

Functional outcomes following oncologic total femoral endoprosthetic reconstruction (TFR) are lacking. We compared patient‐oriented functional results of TFRs to proximal femur and distal femur reconstructions (PFR and DFR). We also compared function and complications with regard to knee and hip componentry.

Prophylactic antibiotic regimens in tumour surgery (PARITY): a pilot multicentre randomised controlled trial

Objective Clinical studies of patients with bone sarcomas have been challenged by insufficient numbers at individual centres to draw valid conclusions. Our objective was to assess the feasibility of conducting a definitive multi-centre randomised controlled trial (RCT) to determine whether a five-day regimen of post-operative antibiotics, in comparison to a 24-hour regimen, decreases surgical site infections in patients undergoing endoprosthetic reconstruction for lower extremity primary bone tumours. Methods We performed a pilot international multi-centre RCT. We used central randomisation to conceal treatment allocation and sham antibiotics to blind participants, surgeons, and data collectors. We determined feasibility by measuring patient enrolment, completeness of follow-up, and protocol deviations for the antibiotic regimens. Results We screened 96 patients and enrolled 60 participants (44 men and 16 women) across 21 sites from four countries over 24 months (mean 2.13 participants per site per year, standard deviation 2.14). One participant was lost to follow-up and one withdrew consent. Complete data were obtained for 98% of eligible patients at two weeks, 83% at six months, and 73% at one year (the remainder with partial data or pending queries). In total, 18 participants missed at least one dose of antibiotics or placebo post-operatively, but 93% of all post-operative doses were administered per protocol. Conclusions It is feasible to conduct a definitive multi-centre RCT of post-operative antibiotic regimens in patients with bone sarcomas, but further expansion of our collaborative network will be critical. We have demonstrated an ability to coordinate in multiple countries, enrol participants, maintain protocol adherence, and minimise losses to follow-up. Cite this article: Bone Joint Res;4:154–162

Chronology of the Radiographic Appearances of the Calcium Sulfate-Calcium Phosphate Synthetic Bone Graft Composite Following Resection of Bone Tumors: A Follow-up Study of Postoperative Appearances.

Purpose The objective of the study was to characterize the radiographic appearance of graft resorption and new bone incorporation into a postresection defect of the calcium-sulfate calcium-phosphate synthetic bone graft composite following resection of benign bone tumours. Methods Twenty-five patients who underwent treatment with the CaSO4/CaPO4 synthetic graft following bone tumour resection were retrospectively identified from our oncology database. Postoperative radiographs were assessed for: 1) combined partial graft resorption and ingrowth at the graft site; 2) complete graft resorption with complete incorporation of new bone into the defect. After chronologically grouping radiographs, the volume of graft material used to fill bony defects, radiographic evidence of complications, and patterns of resorption were recorded. Results Partial resorption of graft material/partial ingrowth of new bone was seen in 21 patients at 2.5 months postoperatively. Complete resorption of graft with complete new bone incorporation at the graft site was seen in 94% of cases (15 of 16) by 10 months after surgery. Mean time to complete incorporation of new bone was 6.7 months. Time to resorption of the graft with new bone ingrowth was found to be related to the volume of graft used with smaller volumes showing earlier resorption. For all cases demonstrating resorption (21 of 21), the pattern observed was peripheral to central. Five patients developed complications, including tumour recurrence, cyst formation, and graft site infection. Conclusion Our study suggests a characteristic time and volume related radiographic pattern of resorption and new bone ingrowth with the CaSO4/CaPO4 synthetic graft. Findings that deviate from this pattern may represent complication and warrant additional follow-up.

Radiology–pathology conference: cutaneous angiosarcoma of the leg

Cutaneous angiosarcoma is a rare aggressive vascular neoplasm with a poor prognosis, seen usually in the elderly population in a background of chronic lymphedema. We present a case of cutaneous angiosarcoma of the leg without any chronic lymphedema with clinicoradiological and histological correlation.