Retrograde Intramedullary Nailing Versus Locked Plating for Extreme Distal Periprosthetic Femur Fractures: A Multicenter Retrospective Cohort Study.

OBJECTIVES: To compare clinical and radiographic outcomes after retrograde intramedullary nailing (rIMN) versus locked plating (LP) of "extreme distal" periprosthetic femur fractures, defined as those that contact or extend distal to the anterior flange. DESIGN: Retrospective review. SETTING: Eight academic level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with periprosthetic distal femur fractures at or distal to the anterior flange (OTA/AO 33B-C[VB1]) treated with rIMN or LP. OUTCOME MEASURES AND COMPARISONS: The primary outcome was reoperation to promote healing or to treat infection (reoperation for elective removal of symptomatic hardware was excluded from this analysis). Secondary outcomes included nonunion, delayed union, fixation failure, infection, overall reoperation rate, distal femoral alignment, and ambulatory status at final follow-up. Outcomes were compared between patients treated with rIMN or LP. RESULTS: Seventy-one patients treated with rIMN and 224 patients treated with LP were included. The rIMN group had fewer points of fixation in the distal segment (rIMN: 3.5 ± 1.1 vs. LP: 6.0 ± 1.1, P < 0.001) and more patients who were allowed to weight-bear as tolerated immediately postoperatively (rIMN: 45%; LP: 9%, P < 0.01). Reoperation to promote union and/or treat infection was 8% in the rIMN group and 16% in the LP group ( P = 0.122). There were no significant differences in nonunion ( P > 0.999), delayed union ( P = 0.079), fixation failure ( P > 0.999), infection ( P = 0.084), or overall reoperation rate ( P > 0.999). Significantly more patients in the rIMN group were ambulatory without assistive devices at final follow-up (rIMN: 35%, LP: 18%, P = 0.008). CONCLUSIONS: rIMN of extreme distal periprosthetic femur fractures has similar complication rates compared with LP, with a possible advantage of earlier return to weight-bearing. Surgeons can consider this treatment strategy in all fractures with stable implants and amenable prosthesis geometry, even extreme distal fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk of thyroid cancer after therapeutic irradiation in adult patients: An Age-Based surveillance, epidemiology, and end results analysis.

OBJECTIVES/HYPOTHESIS: One risk of radiation therapy exposure (XRTe) is second primary thyroid cancer (SPTC). Previous reports examined this in children, but no population-based studies have explored XRTe and SPTC across all ages or stratified by histological subtypes. STUDY DESIGN: Database study. METHODS: We report patient characteristics of a Surveillance, Epidemiology, and End Results (SEER) dataset of SPTC (n = 4,669) using χ2 and t tests. Odds ratio (OR) for SPTC was determined based on age, histology, and XRTe compared to expected values in the SEER database. Kaplan-Meier survival and Cox proportional hazard ratios were reported to determine factors influencing latent survival (LS; time from initial diagnosis to SPTC) and overall survival in univariate and multivariate models. RESULTS: Extrathyroid extension and node status based on XRTe were similar (P = .684 and P = .776, respectively). XRTe patients were more likely to have smaller tumors (17.6 vs. 19.3 mm, P = .007). XRTe patients were diagnosed with SPTC at younger ages (59.8 vs. 62.7 years, P < .001) without a difference in LS (7.45 vs. 7.50 years, P = .426). Patients aged 1 to 14 years and 15 to 29 years at diagnosis of first cancer are at higher risk of SPTC after XRTe (OR = 1.89, P = .005 and OR = 2.35, P = .001, respectively), unlike patients age 30 to 44 years and 45+ years (OR = 1.03, P = .823 and OR = 0.97, P = .624, respectively). This difference is not present for follicular and medullary SPTC. CONCLUSIONS: Patients aged 30+ years receiving radiation therapy (XRT) do not have an increased risk of SPTC. Deliberation is necessary in recommending, planning, and delivering XRT to minimize risk of subsequent malignancy in younger patients. LEVEL OF EVIDENCE: NA Laryngoscope, 130: 2081-2086, 2020.

Genetic characterization of medullary thyroid cancer in childhood survivors of the Chernobyl accident.

BACKGROUND: Radiation-associated fusion oncogenes play a direct role in papillary thyroid cancer development and pathogenic fusions have recently been reported in medullary thyroid cancer. To date, no studies have evaluated oncogenic events in medullary thyroid cancer in a radiation-exposed population. METHODS: Somatic and germline alterations, including RET fusions, were evaluated in paired medullary thyroid cancer tumor and normal samples from the Chernobyl Tissue Bank, a heavily screened population affected by the Chernobyl disaster. RESULTS: Tissue was available for 49 individuals. The median age of diagnosis was 26 years (range 9 to 43 years); 16 were radiation-exposed at a median age of 6 (range 2 days to 17 years). A total of 21 patients harbored germline RET mutations (codons 634[13], 918[5], 790[1], 609[1], and 620[1]); 4 had family history. Sporadic medullary thyroid cancer was identified in 27 patients (RET[18], KRAS[1], RET+KRAS[1], TP53[1], wild type [6]), with 1 RET fusion (1/49;2%). The age at operation for patients with hereditary medullary thyroid cancer was not different than sporadic medullary thyroid cancer (23.5 vs 28 years, P = .063). In sporadic medullary thyroid cancer, radiation was not associated with a difference in age at operation, tumor size, or tumor stage (P > .05). CONCLUSION: In a heavily screened cohort, genetic analysis revealed germline RET mutations in previously unrecognized probands and a remarkable number of sporadic medullary thyroid cancer cases with a young age at presentation.