Prolonged prophylactic antibiotic use following megaprosthesis surgery may reduce periprosthetic infection.

Introduction: Megaprostheses provide a reconstructive option for patients with bone loss after musculoskeletal tumor resection. However, the postoperative surgical site infection (SSI) risk is significant. This study aims to evaluate outcomes of extended postoperative antibiotic regimens in patients after megaprosthesis surgery and gather insight into strategies to minimize SSI. Methods: This retrospective cohort study evaluated patients who underwent megaprosthesis surgery by a single surgeon at a single center from 2014 to 2022. Patient demographics, comorbidities, cancer treatment details, and antibiotic regimens were collected. Excluded were patients with less than 1 year of follow-up, active infection at time of surgery, non-healing wounds unrelated to SSI, and preoperative antibiotic regimens secondary to being immunocompromised. Measures of interest included the development of SSI within 1 year of surgery and development of antibiotic-related complications. Results: Included were 49 patients, with a mean age of 61.2 ± 2.0 years and a mean BMI of 29.4 ± 7.0. The mean drain duration was 6.5 days (standard deviation [SD], 6.9 days), and the mean intravenous antibiotic administration duration was 6.4 days (SD, 6.9 days). The median time to drain removal was five days, and the median time for intravenous antibiotic cessation was five days. The mean total antibiotic administration duration (intravenous and oral) was 25.4 days (SD, 13.4 days). Only 1 patient in the included cohort (2.04 %) developed an SSI requiring operative intervention. No other patient within the cohort experienced an antibiotic-related complication. Discussion: This study suggests that the site's current protocol for managing post-megaprosthesis antibiotic prophylaxis based on drain duration and incision healing status has resulted in a low rate of SSI and antibiotic-related complications. Further research is needed to validate these findings and gain additional insights into managing antibiotic prophylaxis after megaprosthesis surgery.

Are extra locking bolts or fibular plating more important in extreme nailing of distal tibia fractures? A cadaveric biomechanical analysis.

OBJECTIVES: In far-distal extra-articular tibia fracture "extreme" nailing, debate surrounds the relative biomechanical performance of plating the fibula compared with extra distal interlocks. This study aimed to evaluate several constructs for extreme nailing including one interlock (one medial-lateral interlock), one interlock + plate (one medial-lateral interlock with lateral fibula compression plating), and two interlocks (one medial-lateral interlock and one anterior-posterior interlock). METHODS: Fifteen pairs of fresh cadaver legs were instrumented with a tibial nail to the physeal scar. A 1 cm segment of bone was resected from the distal tibia 3.5 cm from the joint and an oblique osteotomy was made in the distal fibula. We loaded specimens with three different distal fixation constructs (one interlock, one interlock + plate, and two interlocks) through 10,000 cycles form 100N-700 N of axial loading. Load to failure (Newtons), angulation and displacement were also measured. RESULTS: Mean load to failure was 2092 N (one interlock), 1917 N (one interlock + plate), and 2545 N (two interlocks). Linear mixed effects modeling demonstrated that two interlocks had a load to failure 578 N higher than one interlock alone (95 % CI, 74N-1082 N; P = 0.02), but demonstrated no significant difference between one interlock and one interlock + plate. No statistically significant difference in rates or timing of displacement >2 mm or angulation >10° were demonstrated. CONCLUSIONS: When nailing far-distal extra-articular tibia and fibula fractures, adding a second interlock provides more stability than adding a fibular plate. Distal fibula plating may have minimal biomechanical effect in extreme nailing.

RNA-sequencing predicts a role of androgen receptor and aldehyde dehydrogenase 1A1 in osteosarcoma lung metastases.

One-third of pediatric patients with osteosarcoma (OS) develop lung metastases (LM), which is the primary predictor of mortality. While current treatments of patients with localized bone disease have been successful in producing 5-year survival rates of 65-70%, patients with LM experience poor survival rates of only 19-30%. Unacceptably, this situation that has remained unchanged for 30 years. Thus, there is an urgent need to elucidate the mechanisms of metastatic spread in OS and to identify targetable molecular pathways that enable more effective treatments for patients with LM. We aimed to identify OS-specific gene alterations using RNA-sequencing of extremity and LM human tissues. Samples of extremity and LM tumors, including 4 matched sets, were obtained from patients with OS. Our data demonstrate aberrant regulation of the androgen receptor (AR) pathway in LM and predicts aldehyde dehydrogenase 1A1 (ALDH1A1) as a downstream target. Identification of AR pathway upregulation in human LM tissue samples may provide a target for novel therapeutics for patients with LM resistant to conventional chemotherapy.