Outcomes of subtalar arthroereisis for the planovalgus foot.

Chronic pain and gait disturbance are possible complications of subtalar arthroereisis. Despite literature indicating a considerably high rate of such complications, subtalar arthroereisis continues to be commonly performed for children with pes planus. The goals of this study are to identify common presenting features and an approach to the treatment of foot pain after subtalar arthroereisis. This case report includes six feet in which subtalar implants were used to treat flatfoot deformities in children. After failing conservative management for chronic postoperative pain, all patients had their implants removed resulting in relief of pain. The expedited removal of subtalar implants in cases of chronic foot pain after arthroereisis is encouraged. The authors do not recommend the use of subtalar arthroereisis in pes planus given its potential complications and literature review indicating a paucity of cases with improved function and activity level as a result of the procedure.

Mosaïcplasty.

Management of the patient with symptomatic full-thickness chondral or osteochondral defects of the knee presents a challenging problem for the orthopedic surgeon. The natural history of untreated lesions demonstrates progressive degenerative changes and deterioration in functional outcome scores. Medical management, osteotomies, lavage, and debridement procedures temporize symptoms and slow progression. Cartilage restoration procedures such as microfracture and cell-based therapies have shown promise, but there are concerns of the long-term durability of these procedures in the active population. Mosaicplasty allows for restoration of articular defects with hyaline cartilage, and has shown excellent durability. Articular defect should measure between 1 to 4 cm(2) in diameter and extend 10 mm into subchondral bone. Mosaicplasty can be challenging when attempted arthroscopically, and the threshold to convert to an open procedure should be low when adequate visualization is not achieved. Use of variable graft size maximizes defect fill with hyaline cartilage. Avoidance of graft prominence >1 mm and attention to the contour of the joint optimizes the recreation of articular surface. This is achieved by placing central grafts in a large defect slightly prouder to obtain a convex shape to the articular surface. With attention to the nuances of the surgical technique, mosaicplasty offers an excellent option for cartilage restoration in the young active patient.

Use of radioisotope bone scans in children with obscure foot pain.

Foot pain in pediatric patients often presents as a diagnostic challenge. Studies in adults with foot pain have shown that bone scans are valuable diagnostic tools, especially in instances in which clinical evaluation and conventional radiography have failed to provide a clear answer. To our knowledge, no similar investigation has ever been conducted in the pediatric population. The objective of this study was to determine the utility of bone scans as a diagnostic tool for children with foot pain of unclear etiology. Our secondary objective was to determine whether obtaining a bone scan, in fact, alters the treatment plan of such patients. Chart review was done, documenting the prebone scan versus post bone scan diagnosis and treatment plans. We found that bone scans were diagnostically useful in 38 of 49 [77.6%, 66-87, 90% confidence interval (CI)] cases, helping to establish new diagnoses in 31 of 49 (63%, 51-75, 90% CI) cases, and directing the treatment of children with clinically unclear foot pain in 31 of 49 (63%, 51-75, 90% CI) cases. We conclude that children between the age of 2 and 11 years who present with unilateral or bilateral foot pain of unclear clinical etiology, with a normal or inconclusive radiograph and physical examination, and who had no previous magnetic resonance imaging and/or computed tomography scan, may benefit from the use of a bone scan to guide diagnosis and treatment.

Contribution of GIRK2-mediated postsynaptic signaling to opiate and alpha 2-adrenergic analgesia and analgesic sex differences.

The analgesia produced by inhibitory G protein-coupled receptor agonists involves coordinated postsynaptic inhibition via G protein-coupled inwardly rectifying potassium channels (GIRKs) and presynaptic inhibition of neurotransmitter release through regulation of voltage-gated Ca(2+) channels. Here, we used mice lacking the GIRK2 channel subunit to assess the relative contribution of these two effector systems to nociceptive processing in male and female mice. Compared with female WT mice, male WT mice exhibited higher pain thresholds and enhanced opioid (morphine) and alpha(2)-adrenergic (clonidine) receptor-induced antinociception in a spinal reflex test. The GIRK2-null mutation reduced the "pain" threshold in male but not in female mice, effectively eliminating the sex differences in pain threshold. In addition, deletion of GIRK2 channels in mutant mice largely eliminated clonidine antinociception and significantly decreased morphine antinociception. Furthermore, the more pronounced morphine and clonidine-induced antinociception in male mice disappeared in the GIRK2 mutants. Based on the almost complete loss of clonidine-induced antinociception in the mutant mice, we conclude that it is primarily mediated by postsynaptic alpha(2)-adrenergic receptors. In contrast, the significant residual morphine effect in the mutant mice points to the presynaptic mu opioid receptor as a major contributor to its analgesic action. Finally, our results suggest that the reduced pain responsiveness of male compared with female mice results in part from GIRK2-coupled postsynaptic receptors that are activated by endogenous antinociceptive systems.