Brian Brigman

BACKGROUND: Vascularized fibula epiphyseal flap was first described in 1998 for proximal humeral reconstruction in children/infants. The authors aim to review their international, multi-institutional, long-term outcomes. METHODS: An international, multi-institutional review (2004 to 2020) was conducted of patients younger than 18 years undergoing free vascularized fibula epiphyseal transfer for proximal humeral reconstruction. Donor- and recipient-site complications, pain, and final ambulatory status were reviewed. Growth of the transferred bone was assessed under the guidance of a pediatric musculoskeletal radiologist. RESULTS: Twenty-seven patients were included with a median age of 7 years (range, 2 to 13 years). Average follow-up was 120 ± 87.4 months. There were two flap failures (7.4%). Recipient-site complications included fracture [ n = 11 (40.7%)], avascular necrosis of the fibula head [ n = 1 (3.7%)], fibular head avulsion [ n = 1 (3.7%)], infection [ n = 1 (3.7%)], and hardware failure [ n = 1 (3.7%)]. Operative fixation was necessary in one patient with a fracture. The case of infection necessitated fibula explantation 2 years postoperatively, and ultimately, prosthetic reconstruction. Sixteen patients developed peroneal nerve palsy (59.3%): 13 of these cases resolved within 1 year (81% recovery), and three were permanent (11.1%). One patient (3.7%) complained of upper extremity pain. Longitudinal growth was confirmed in all but three cases [ n = 24 (88.9%)] at an average rate of 0.83 ± 0.25 cm/year. CONCLUSIONS: The vascularized fibula epiphysis for proximal humerus reconstruction in children preserves the potential for future growth and an articular surface for motion. Peroneal nerve palsy is common following harvest, although this is often transient. Future efforts should be geared toward reducing postoperative morbidity. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

PURPOSE: To measure the ablation zone temperature and nontarget tissue temperature during radiofrequency (RF) ablation in bone containing metal instrumentation versus no metal instrumentation (control group). MATERIALS AND METHODS: Ex vivo experiments were performed on 15 swine vertebrae (control, n = 5; titanium screw, n = 5; stainless steel screw, n = 5). Screws and RF ablation probe were inserted identically under fluoroscopy. During RF ablation (3 W, 5 minutes), temperature was measured 10 mm from RF ablation centerpoint and in muscle contacting the screw. Magnetic resonance (MR) imaging, gross pathologic, and histopathologic analyses were performed on 1 specimen from each group. RESULTS: Ablation zone temperatures at 2.5 and 5 minutes increased by 12.2 °C ± 2.6 °C and 21.5 °C ± 2.1 °C (control); 11.0 °C ± 4.1 °C and 20.0 °C ± 2.9 °C (juxta-titanium screw), and 10.0 °C ± 3.4 °C and 17.2 °C ± 3.5 °C (juxta-stainless steel) screw; differences among groups did not reach significance by analysis of variance (P = .87). Mixed-effects linear regression revealed a statistically significant increase in temperature over time in all 3 groups (4.2 °C/min ± 0.4 °C/min, P < .001). Compared with the control, there was no significant difference in the temperature change over time for titanium (-0.3 °C/min ± 0.5 °C/min, P = .53) or steel groups (-0.4 °C/min ± 0.5 °C/min, P = .38). The mean screw temperature at the final time point did not show a statistically significant change compared with baseline in either the titanium group (-1.2 °C ± 2.3 °C, P = .50) or steel group (2.6 °C ± 2.9 °C, P = .11). MR imaging and pathologic analyses revealed homogeneous ablation without sparing of the peri-hardware zones. CONCLUSIONS: Adjacent metallic instrumentation did not affect the rate of or absolute increase in temperature in the ablation zone, did not create peri-metallic ablation inhomogeneities, and did not result in significant nontarget heating of muscle tissue in contact with the metal instrumentation.

In orthopedic oncology, the implant of a megaprosthetic device is standard of care after large-scale tumor resection involving segmental removal of bone. Infection remains the leading cause of implant failure, often resulting in major morbidity. Perioperative antibiotic practices for megaprosthetic reconstructions are not standardized and are based on guidelines for conventional joint arthroplasties. This study aims to evaluate the efficacy of current prophylactic strategies for megaprosthetic reconstructions. We conducted a retrospective review of megaprosthetic reconstructions performed at Duke University from 2001 to 2021. Logistic regression with GEE was used to assess whether a prolonged course of postoperative antibiotics is associated with infection risk. We assessed the microbial profile and corresponding susceptibilities of megaprosthetic infections through record review. Additionally, we designed a pharmacokinetic subgroup analysis using liquid chromatography-tandem mass spectrometry to quantify antibiotic concentrations in surgical tissue. Wilcoxon rank-sum tests were used to correlate tissue concentrations with infection risk. Out of 184 cases, 23 (12.5%) developed infection within 1 year. Extended postoperative antibiotics were not significantly associated with infection risk (P = 0.23). Among 18 culture-positive cases, 4 (22.2%) were caused by cefazolin-susceptible organisms. Median bone and muscle concentrations of cefazolin among cases that developed postoperative infection (0.065 ng/mL and 0.2 ng/mL, respectively) were significantly lower than those of cases that did not (0.42 ng/mL and 1.95 ng/mL, P < 0.01 and P = 0.03). This study is the first to comprehensively assess aspects of perioperative prophylaxis for megaprosthetic reconstructions. Extending postoperative antibiotics did not reduce infection risk. We detected a high frequency of cefazolin nonsusceptible organisms among postoperative infections. Additionally, intraoperative antibiotic tissue concentrations may be predictive of later infection. Future studies ought to examine optimal drug choices and dosing strategies.

For soft tissue sarcoma patients receiving preoperative radiation therapy, wound complications are common and potentially devastating. The purpose of this study was to assess the feasibility of intraoperative indocyanine green fluorescent angiography (ICGA) as a predictor of wound complications in these patients. A consecutive series of patients with soft tissue sarcoma of the extremities or pelvis who received neoadjuvant radiation and a subsequent radical resection received intraoperative ICGA with the SPY PHI device (Stryker Inc.) at the time of closure. Retrospective analysis of fluorescence signal along multiple points of the wound length was performed and quantified. The primary endpoint was wound complication, defined as delayed wound healing or wound dehiscence, within 3 months of surgery. Fourteen patients with preoperative irradiated soft tissue sarcoma were consecutively imaged. There were six patients with wound complications classified as "aseptic" in five cases. Using the ICGA, blinded surgeons correctly predicted wound complications in 75% of cases. During the inflow phase, a mean ratio of normal of 0.62 maximized the area under the curve (AUC = 0.90) for predicting wound complications with a sensitivity of 100% and specificity of 77.4%. During the peak phase, a mean ratio of normal of 0.55 maximized the AUC (0.95) for predicting wound complications with a sensitivity of 88.9% and a specificity of 100%. Intraoperative use of ICGA may help to predict wound complications in patients undergoing resection of preoperatively irradiated soft tissue sarcomas of the extremities and pelvis.