Faculty Bibliography

BACKGROUND:We compared forefoot and calcaneocuboid pressure in isolated medial column fusion (1-3 tarsometatarsal fusion) versus medial and lateral column fusion (1-5 tarsometatarsal fusion) in a neutral, inversion, and eversion loading model in stance gait phase. METHODS:Twelve fresh-frozen cadaveric specimens were cyclically loaded to 720 N at 0.5 Hz for 30 cycles. Plantar and calcaneocuboid joint pressures were measured in neutral, inversion, and eversion in the intact foot, with isolated medial column fusion, and with medial and lateral column fusion. RESULTS:Lateral pressure was higher in the medial and lateral column fusion group than isolated medial column fusion and intact in neutral (55.8 +/- 14.8 versus 46.2 +/- 13.6 and 45.5 +/- 14.8 kPa, respectively) and eversion (80.7 +/- 18.4 versus 61.8 +/- 13.7 and 60.2 +/- 18.2 kPa, respectively) (p < or = 0.001). Calcaneocuboid pressure was higher in medial and lateral column fusion than isolated medial column fusion and intact in neutral (1436.7 +/- 210.6 versus 1073.7 +/- 282.5 and 1084.9 +/- 337.6, respectively; p = 0.001) and inversion (1518.3 +/- 270.5 versus 1310.5 +/- 298.8 and 1237.1 +/- 401.9, respectively; p = 0.02). Using combined position data, calcaneocuboid pressure was significantly higher in the medial and lateral column group than in both other groups. The isolated medial column fusion group did not differ significantly from the intact group in any measurement. CONCLUSION/CONCLUSIONS:Medial and lateral column fusion significantly increased lateral and calcaneocuboid pressures with loading compared with isolated medial column fusion and the intact state. No difference was observed between isolated medial column fusion and the intact state. CLINICAL RELEVANCE/CONCLUSIONS:It may be advisable to avoid fusing the lateral column in tarsometatarsal arthrodesis if possible to avoid pressure increase in the forefoot and hindfoot.

Interdigital neuralgia affects a significant number of individuals, with an average age of presentation in the sixth decade and a 4- to 15-fold increased prevalence in women. Historical descriptions date back to the 19th century. Nonoperative treatment with shoe modifications, metatarsal pads, and injections provides relief for most, but long term, 60% to 70% of patients eventually elect to have surgery. Although excision can be performed through a dorsal or plantar approach, we prefer the dorsal incision to prevent scar formation on the plantar aspect of the foot. Satisfactory results are common but not certain with reports of excellent or good ranging from 51% to 93%.

Recurrent or persistent symptoms following surgical neurectomy for an interdigital neuroma are quite common, because of incorrect initial diagnosis, true neuroma formation, nerve stump adhesions, accessory nerve branches, or an adjacent web space neuroma. The clinical presentation of a recurrent neuroma is similar to the initial presentation. Recurrent symptoms usually occur within the first 12 months after surgery. The physical examination coupled with diagnostic nerve blocks is critical for diagnosis. Conservative therapy, although not particularly effective in treating true recurrent neuromas, may help to alleviate pain. With proper isolation of the instigating neuroma, revision surgical excision can be effective.

The posterior tibial tendon (PTT) is the most important dynamic stabilizer of the medial ankle and longitudinal arch of the foot. PTT dysfunction is a degenerative disorder of the tendon, which secondarily involves multiple ligaments, joint capsules, fascia, articulations, and bony structures of the ankle, hindfoot, midfoot, and forefoot. When the tendon progressively attenuates, the patient develops a painful, progressive collapsed flatfoot or pes planovalgus deformity. This comprehensive review illustrates the 3-Tesla magnetic resonance imaging (3T MRI) features of PTT dysfunction. In addition, the reader will gain knowledge of the expected pathologic findings on MRI, as they are related to clinical staging of PTT dysfunction.

Augmented retrograde intramedullary (IM) nail fixation was compared with augmented periarticular locking- plate fixation for tibiotalocalcaneal arthrodesis. Specimens in 10 matched pairs were randomly assigned to a fixation construct and loaded cyclically in dorsiflexion. The groups did not differ in initial or final stiffness, load to failure, or construct deformation. No correlation was found between bone mineral density and construct deformation for either group. A humeral locking plate may be a viable alternative to an IM nail for tibiotalocalcaneal fixation in cases not amenable to IM nailing.

BACKGROUND:Tendon disorders (tendinopathies) pose serious biomedical and socioeconomic problems. Despite diverse treatment approaches, the best treatment strategy remains unclear. Surgery remains the last resort because of the associated morbidity and inconsistent outcomes. We hypothesized that, similar to fibroblasts in various organs, tendon fibroblasts (tenocytes) might be responsive to stimulation with interleukins (ILs), particularly IL-4 and IL-13. These two cytokines share sequence homology, receptor chains and functional effects, including stimulation of fibrogenesis. It is unknown whether tenocytes are responsive to stimulation with IL-4 or IL-13. If true, local use of these cytokines might be used to facilitate tendon repair in patients with tendinopathies or used for tendon tissue-engineering approaches to facilitate tenocyte growth on scaffolds in culture. RESULTS:Tendon tissues that would normally be discarded were obtained during reconstructive surgery procedures performed for clinical indications. Primary tenocytes were derived from Achilles, posterior tibial, flexor digitorum longus and flexor hallucis longus tendon tissue samples. Reverse transcriptase quantitative PCR (RT-qPCR) experiments revealed that mRNAs for the receptor (R) chains IL-4Ralpha, IL-13Ralpha1 and IL-13Ralpha2, but not the common gamma-chain were present in all tested tendon tissues and in cultured tenocytes. Levels of IL-13R chain mRNAs were significantly higher than those of IL-4R mRNA. The cultures responded, in a dose-dependent fashion, to stimulation with recombinant human IL-4 or IL-13, by increasing proliferation rates 1.5 to 2.0-fold. The mRNA levels of 84 genes related to cell cycle regulation were measured by RT-qPCR after 6 h and 24 h of activation. The expression levels of several genes, notably CDK6 and CDKN2B changed more than twofold. In contrast to their effects on proliferation, stimulation with IL-4 or IL-13 had little if any effect on the levels of collagen mRNA or protein in cultured primary tenocytes. The mRNA levels of 84 other genes related to extracellular matrix and cell adhesion were also measured by RT-qPCR; expression of only five genes was consistently changed. CONCLUSIONS:Stimulation with IL-4 or IL-13 could be used to facilitate tendon repair in vivo or to aid in tendon tissue engineering, through stimulation of tenocyte proliferation.