Analysis of release of the first branch of the lateral plantar nerve.

The authors conducted a retrospective study of the release of the first branch of the lateral plantar nerve in the treatment of chronic heel pain unrelieved by conservative treatment modalities. A total of 17 patients (18 feet) were evaluated following external neurolysis for heel pain caused by entrapment of the first branch of the lateral plantar nerve. The average postoperative follow-up time was 32.8 months, with a range of 10 to 72 months. Every patient deemed the surgery successful. At the time of follow-up examination, nine feet were asymptomatic and nine feet experienced mild pain after extended activity. There was one postoperative complication, medial calcaneal nerve entrapment; it was successfully treated with neurectomy.

Activation of downstream signals by the long form of the leptin receptor.

The adipocyte-derived hormone leptin signals the status of body energy stores by activating the long form of the leptin receptor (LRb). Activation of LRb results in the activation of the associated Jak2 tyrosine kinase and the transmission of downstream phosphotyrosine-dependent signals. We have investigated the signaling function of mutant LRb intracellular domains under the control of the extracellular erythropoietin (Epo) receptor. By using this system, we confirm that two tyrosine residues in the intracellular domain of murine LRb become phosphorylated to mediate LRb signaling; Tyr(985) controls the tyrosine phosphorylation of SHP-2, and Tyr(1138) controls STAT3 activation. We furthermore investigated the mechanisms by which LRb controls downstream ERK activation and c-fos and SOCS3 message accumulation. Tyr(985)-mediated recruitment of SHP-2 does not alter tyrosine phosphorylation of Jak2 or STAT3 but results in GRB-2 binding to tyrosine-phosphorylated SHP-2 and is required for the majority of ERK activation during LRb signaling. Tyr(985) and ERK activation similarly mediate c-fos mRNA accumulation. In contrast, SOCS3 mRNA accumulation requires Tyr(1138)-mediated STAT3 activation. Thus, the two LRb tyrosine residues that are phosphorylated during receptor activation mediate distinct signaling pathways as follows: SHP-2 binding to Tyr(985) positively regulates the ERK --> c-fos pathway, and STAT3 binding to Tyr(1138) mediates the inhibitory SOCS3 pathway.

Recurrent intermetatarsal neuroma. A follow-up study.

Sixteen patients were evaluated following excision of recurrent intermetatarsal neuroma. Each underwent removal of a segment of nerve through an incision on the plantar aspect. The nerve stump was buried in the flexor digitorum brevis muscle. At the time of follow-up examinations, six patients were asymptomatic, seven experienced mild pain after extended activity, one suffered mild consistent pain with activity, and two suffered pain that limited activities.

Juvenile hallux abducto valgus association with metatarsus adductus.

The authors evaluated the radiographs of 40 patients (72 feet) under 21 years of age who underwent surgery for symptomatic hallux abducto valgus deformity at Northlake Regional Medical Center. Forty-eight of 72 feet had metatarsus adductus angles greater than 15 degrees. A statistically significant correlation was found between an increasing metatarsus adductus angle and an increasing hallux abductus angle.

"Z" incision and surgical access to the plantar aspect of the foot.

The authors describe their experience with the "Z" incision, when extensive surgery is performed on the plantar aspect of the foot.