Hip Fractures: Relevant Anatomy, Classification, and Biomechanics of Fracture and Fixation.

INTRODUCTION: Hip fractures represent an important health-care dilemma, costing the US$ billions annually. Hip fractures can diminish quality of life and significantly increase morbidity and mortality if not properly treated. Recent research has brought forth new information regarding treatment as well as information on emerging complications seen within the fixation constructs themselves. SIGNIFICANCE: Understanding the pathoanatomy of hip fractures and the biomechanics of surgical fixation constructs is critical for successful treatment. In this article, we review the relevant anatomy and classification of femoral neck and intertrochanteric fractures. Furthermore, the biomechanics of hip fracture fixation strategies as well as implant-related complications are addressed. RESULTS: Even though laboratory testing demonstrated that intramedullary nails have greater biomechanical stability, the clinical results between fixation constructs have been similar when the chosen implant (ie, sliding hip screw vs cephalomedullary nail) has been correctly applied to the specific fracture pattern. Recently, data have shown that when using cephalomedullary nails, there is potential for increased failure with cutout when using the helical blade versus the lag screw, with majority being the atypical "medial cutout." CONCLUSION: The goal of surgical treatment of hip fractures is surgical treatment that allows for early mobilization and weight bearing. A full understanding of the anatomy and fracture characteristics will allow the surgeon to correctly apply the right implant to allow for uneventful healing. Surgeons need to be aware, however, of complications that can arise when using specific implants. Further research is ongoing to further determine the treatments that will allow optimal cost-effective care for the geriatric patient with hip fracture.

Open Reduction Internal Fixation of the Lisfranc Complex.

Lisfranc injuries are uncommon; however, if left untreated, it can have a detrimental effect causing deformity, chronic pain, and mid-foot arthrosis. Injury can include disruption of the first through fifth tarsometatarsal joints as well as variant patterns that include the involvement of the metatarsals, the naviculocuneiform articulation, and the cuboid. There is controversy regarding the benefits of open reduction internal fixation versus arthrodesis. Regardless, anatomical reduction is paramount to obtaining a good functional outcome. This video details the surgical approach and the reduction and fixation strategy of a high-energy Lisfranc complex fracture dislocation.

Foot-Ankle Fractures and Injury Probability Curves from Post-mortem Human Surrogate Tests.

This purpose of this study was to replicate foot-ankle injuries seen in the military and derive human injury probability curves using the human cadaver model. Lower legs were isolated below knee from seventeen unembalmed human cadavers and they were aligned in a 90-90 posture (plantar surface orthogonal to leg). The specimens were loaded along the tibia axis by applying short-time duration pulses, using a repeated testing protocol. Injuries were documented using pre- and post-test X-rays, computed tomography scans, and dissection. Peak force-based risk curves were derived using survival analysis and accounted for data censoring. Fractures were grouped into all foot-ankle (A), any calcaneus (B), and any tibia injuries (C), respectively. Calcaneus and/or distal tibia/pilon fractures occurred in fourteen tests. Axial forces were the greatest and least for groups C and B, respectively. Times attainments of forces for all groups were within ten milliseconds. The Weibull function was the optimal probability distribution for all groups. Age was significant (p < 0.05) for groups A and C. Survival analysis-based probability curves were derived for all groups. Data are given in the body of paper. Age-based, risk-specific, and continuous distribution probability curves/responses guide in the creation of an injury assessment capability for military blast environments.

Geriatric Patients With Fractures Below the Hip are Medically Similar to Geriatric Patients With Hip Fracture.

The objective of this study was to compare a cohort of geriatric patients with operatively managed isolated fractures below the hip to a cohort of geriatric patients with operatively managed isolated hip fractures. All patients greater than 59 years of age admitted to our institution for surgical care of an isolated lower extremity fracture during a 3-year period were included. Patients were divided into 2 cohorts: BTH (fracture below the subtrochanteric region of the femur) and HIP (proximal femoral fracture at subtrochanteric region or proximal). We identified 141 patients included in cohort BTH and 205 patients included in cohort HIP. HIP patients were older (P < .01) and less obese (P < .01) but were otherwise very similar. An extensive comorbidity review revealed that the 2 cohorts were similar, with the exception of an increased incidence of dementia (P = .012) or glaucoma (P = .04) in HIP patients and of peripheral neuropathy (P = .014) in BTH patients. HIP patients were more likely to be under active antiosteoporotic medication management and were more likely to be receiving pharmacological anticoagulation at the time of admission. HIP patients and BTH patients were similar with regard to necessity of assistance with ambulation preinjury, but HIP patients were less likely to reside independently at home than were BTH patients (P < .001). HIP patients were also less likely to be discharged directly home from the hospital (P < .001). Geriatric patients with fractures below the hip are medically similar to geriatric patients with hip fracture. Medical comanagement protocols have been extensively published that improve care of geriatric patients with hip fracture; consideration should be given to similar protocol-driven medical comanagement programs for geriatric patients with fractures below the hip.

Stimulation of dopamine D2 receptors in the nucleus accumbens inhibits inflammatory pain.

Previous studies suggest that dopamine in the nucleus accumbens links noxious or mesolimbic stimulation with the feedback inhibition of nociception. To test the hypothesis that pharmacological agonism at dopamine receptors in the nucleus accumbens elicits antinociception, we bilaterally microinjected dopamine D1- and D2-receptor subtype selective drugs, and then evaluated behavioral responses to noxious intraplantar formalin. While the D1-selective agonist SKF 38393 was without effect at a dose of 0.5 nmol/side, the D2-selective agonist quinpirole dose-dependently (0.05-5.0 nmol/side, bilateral) inhibited the persistent phase of formalin-induced nociception. This was blocked by pre-administration of a selective D2-dopaminergic antagonist raclopride (0.3 nmol/side, bilateral). Quinpirole did not produce overt behavioral effects and did not change rotarod latency. Our results indicate that quinpirole acts at dopamine D2 receptors in the nucleus accumbens to inhibit persistent nociception at doses that circumvent confounding non-specific motor deficits, namely, sedation and motor coordination.