Browsing by Author "Mendenhall, Stephen"

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    Institutional review of the management of type II odontoid fractures: associations and outcomes with fibrous union
    (AANS, 2021-04) Wilson, Christopher; Hoyos, Mariana; Huh, Andrew; Priddy, Blake; Avila, Stephen; Mendenhall, Stephen; Anokwute, Miracle C.; Eckert, George J.; Stockwell, David W.; Neurological Surgery, School of Medicine
    OBJECTIVE Type II odontoid fractures may be managed operatively or nonoperatively. If managed with bracing, bony union may never occur despite stability. This phenomenon is termed fibrous union. The authors aimed to determine associations with stable fibrous union and compare the morbidity of patients managed operatively and nonoperatively. METHODS The authors performed a retrospective review of their spine trauma database for adults with type II odontoid fractures between 2015 and 2019. Two-sample t-tests and Fisher’s exact tests identified associations with follow-up stability and were used to compare operative and nonoperative outcomes. Sensitivity, specificity, and predictive values were calculated to validate initial stable upright cervical radiographs related to follow-up stability. RESULTS Among 88 patients, 10% received upfront surgical fixation, and 90% were managed nonoperatively, of whom 22% had fracture instability on follow-up. Associations with instability after nonoperative management include myelopathy (OR 0.04, 95% CI 0.0–0.92), cerebrovascular disease (OR 0.23, 95% CI 0.06–1.0), and dens displacement ≥ 2 mm (OR 0.29, 95% CI 0.07–1.0). Advanced age was not associated with follow-up instability. Initial stability on upright radiographs was associated with stability on follow-up (OR 4.29, 95% CI 1.0–18) with excellent sensitivity and positive predictive value (sensitivity 89%, specificity 35%, positive predictive value 83%, and negative predictive value 46%). The overall complication rate and respiratory failure requiring ventilation on individual complication analysis were more common in operatively managed patients (33% vs 3%, respectively; p = 0.007), even though they were generally younger and healthier than those managed nonoperatively. Operative or nonoperative management conferred no difference in length of hospital or ICU stay, discharge disposition, or mortality. CONCLUSIONS The authors delineate the validity of upright cervical radiographs on presentation in association with follow-up stability in type II odontoid fractures. In their experience, factors associated with instability included cervical myelopathy, cerebrovascular disease, and fracture displacement but not increased age. Operatively managed patients had higher complication rates than those managed without surgery. Fibrous union, which can occur with nonoperative management, provided adequate stability.
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    Minced muscle autografting improves bone healing but not muscle function in a porcine composite injury model
    (Wiley, 2023-09) McKinley, Todd O.; Natoli, Roman N.; Janakiram, Naveena B.; Warden, Stuart J.; Fuchs, Robyn K.; Gunderson, Zachary; Diggins, Nichlaus; Sun, Seungyup; Kolettis, George; Goldman, Stephen M.; Dearth, Christopher L.; Mendenhall, Stephen; Staut, Caio; Kacena, Melissa A.; Corona, Benjamin T.; Health Sciences, School of Health and Human Sciences
    Composite tissue injuries (CTIs) in extremities include segmental bone defects (SBDs) and volumetric muscle loss. The objective of this study was to determine if skeletal muscle autografting with minced muscle grafts (MMGs) could improve healing in an SBD and improve muscle function in a porcine CTI model that includes an SBD and adjacent volumetric muscle loss injury. Adult Yucatan Minipigs were stratified into three groups including specimens with an isolated SBD, an SBD with volumetric muscle loss (CTI), and an SBD with volumetric muscle loss treated with MMG (CTI + MMG). Bone healing was quantified with serial x-rays and postmortem computed tomography scanning. Muscle function was quantified with a custom in vivo force transducer. Muscle tissue content was determined by biochemical analyses and histology. Anterior cortex-modified Radiographic Union Score for Tibia fractures (mRUSTs) decreased from 2.7 to 1.9 (p = 0.003) in CTI versus SBD animals. MMG improved anterior mRUST scores to 2.5 in CTI + MMG specimens (p = 0.030 compared to CTI specimens) and overall mRUST scores increased from 9.4 in CTI specimens to 11.1 in CTI + MMG specimens (p = 0.049). Residual strength deficits at euthanasia were 42% in SBD (p < 0.001), 44% in CTI (p < 0.001), and 48% in CTI + MMG (p < 0.001) compared to preoperative values. There were no differences in strength deficits between the three groups. Biochemical and histologic analyses demonstrated scattered differences between the three groups compared to contralateral muscle. MMG improved bone healing. However, the primary cause of muscle dysfunction and biochemical changes was the presence of an SBD. Clinical significance: Early mitigation of SBDs may be necessary to prevent muscle damage and weakness in patients sustaining composite extremity trauma.