Staged treatment of high energy midfoot fracture dislocations.

BACKGROUND: Staged care with interval external fixation is a successful established treatment strategy for high energy periarticular fractures with often extensive soft tissue damage such as the tibial plateau and plafond. The aim of the current study was to determine whether staged care of high energy midfoot fracture/dislocation with interval external fixation prior to definitive open reconstruction in the polytraumatized patient was both safe and efficacious. METHODS: One hundred twenty-three patients were operated on for high energy midfoot fracture/dislocation during the 8-year study period. Eighteen polytrauma patients were selectively treated with a staged protocol. Radiographic assessment was utilized to determine if the fixator achieved gross skeletal alignment. Further, final alignment after definitive reconstruction and postoperative complications were analyzed. RESULTS: The fixator improved both length and alignment of all high energy midfoot fracture/dislocations. Loss of acceptable reduction while in the temporary frame occurred in only 1 case. Final alignment after definitive reconstruction was anatomic in all cases. No cases of wound-related complication and/or deep infection occurred. CONCLUSION: Delayed reconstruction of high energy midfoot fracture/dislocation using interval external fixation should be an accepted care paradigm in selected polytrauma patients. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Characterization of mu, kappa, and delta opioid binding in amphibian whole brain tissue homogenates.

Opioid agonists produce analgesia in mammals through the activation of mu, kappa, or delta opioid receptors. Previous behavioral and binding studies from our laboratory using an amphibian model suggested that mu, kappa, or delta opioid agonists may activate a single type of opioid receptor in the grass frog, Rana pipiens. In the present study, kinetic, saturation, and competitive binding profiles for three opioid radioligands, [(3)H]DAMGO ([D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin) (mu-selective), [(3)H]U65953 [(5 alpha, 7 alpha,8 beta)-(+)-N-methyl-N-[7-(1-pyrrolidinyl)-1-oxaspiro[4.5]dec-8-yl]-benzeneacetamide] (kappa-selective), and [(3)H]DPDPE ([D-Pen(2),D-Pen(5)]-enkephalin) (delta-selective) were determined using frog whole brain homogenates. Kinetic analyses and experimentally derived values from saturation experiments gave affinity constants (K(D)) in the low nanomolar range. The density of opioid binding sites (B(max)) was 224.4, 118.6, and 268.9 fmol/mg for mu, kappa, and delta opioid radioligands, respectively. The affinity values did not significantly differ among the three opioid radioligands, but the kappa radioligand bound to significantly fewer sites than did the mu or delta radioligands. K(i) values for unlabeled mu, kappa, and delta competitors, including highly selective opioid antagonists, were consistent with each radioligand selectivity profile. The present data suggest that mu, kappa, and delta opioid radioligands bind to distinct opioid receptors in amphibians that are surprisingly similar to those found in mammalian brain.