Single-Limb Irradiation Induces Local and Systemic Bone Loss in a Murine Model.

Increased fracture risk is commonly reported in cancer patients receiving radiotherapy, particularly at sites within the field of treatment. The direct and systemic effects of ionizing radiation on bone at a therapeutic dose are not well-characterized in clinically relevant animal models. Using 20-week-old male C57Bl/6 mice, effects of irradiation (right hindlimb; 2 Gy) on bone volume and microarchitecture were evaluated prospectively by microcomputed tomography and histomorphometry and compared to contralateral-shielded bone (left hindlimb) and non-irradiated control bone. One week postirradiation, trabecular bone volume declined in irradiated tibias (-22%; p < 0.0001) and femurs (-14%; p = 0.0586) and microarchitectural parameters were compromised. Trabecular bone volume declined in contralateral tibias (-17%; p = 0.003), and no loss was detected at the femur. Osteoclast number, apoptotic osteocyte number, and marrow adiposity were increased in irradiated bone relative to contralateral and non-irradiated bone, whereas osteoblast number was unchanged. Despite no change in osteoblast number 1 week postirradiation, dynamic bone formation indices revealed a reduction in mineralized bone surface and a concomitant increase in unmineralized osteoid surface area in irradiated bone relative to contralateral and non-irradiated control bone. Further, dose-dependent and time-dependent calvarial culture and in vitro assays confirmed that calvarial osteoblasts and osteoblast-like MC3T3 cells were relatively radioresistant, whereas calvarial osteocyte and osteocyte-like MLO-Y4 cell apoptosis was induced as early as 48 hours postirradiation (4 Gy). In osteoclastogenesis assays, radiation exposure (8 Gy) stimulated murine macrophage RAW264.7 cell differentiation, and coculture of irradiated RAW264.7 cells with MLO-Y4 or murine bone marrow cells enhanced this effect. These studies highlight the multifaceted nature of radiation-induced bone loss by demonstrating direct and systemic effects on bone and its many cell types using clinically relevant doses; they have important implications for bone health in patients treated with radiation therapy.

Documentation of specific mesh implant at the time of midurethral sling surgery in women with stress incontinence.

OBJECTIVE: We aimed to assess documentation completeness of the operative record for mesh implanted at the time of midurethral sling surgery and to identify modifiable predictors of documentation completeness. METHODS: A retrospective cross-sectional study of women with stress incontinence who underwent midurethral sling placement between January 2009 and December 2011 was conducted. Data from the dictated operative note and nursing operative record were extracted to determine if the specific mesh implanted during surgery was documented. The primary outcome was the rate of documentation of mesh implanted in the physician's dictated operative note and in the nursing record. Logistic regression was used to determine if any characteristics were associated with the rate of documentation while accounting for correlation of patients from the same dictating surgeon. RESULTS: There were 816 surgeries involving the implantation of a midurethral sling during the study period. All surgeries were performed at 6 Indiana University hospitals. Fifty-two surgeons of varying specialties and levels of training dictated the operative notes. A urogynecologist dictated 71% of the operative notes. The rate of documentation completeness for mesh implanted in the physician's note was 10%. The rate of documentation completeness for mesh implanted in the nursing operative record was 92%. Documentation of mesh implanted in the physician's note was not significantly associated with the level of training, specialty, or year of surgery. CONCLUSIONS: Documentation completeness for specific mesh implant in the physician's note is low, independent of specialty and level of training. Nursing documentation practices are more rigorous. Postmarket surveillance, currently mandated by the Food and Drug Administration, may not be feasible if only the physician's note is available or if nursing practices are inconsistent. Development of documentation guidelines for physicians would improve the feasibility of surveillance.