Structures at risk with medial double hindfoot fusion: a cadaveric study.

Although discussed as an alternative to triple arthrodesis for hindfoot correction, the published data surrounding the medial double arthrodesis, or fusion of the subtalar and talonavicular joints, has not addressed the proximity of the anatomic structures at risk. A total of 10 cadaver specimens were used to examine the risk of damage to the neurovascular and tendinous structures of the posterior medial hindfoot when performing the medial double arthrodesis. The distance of the reviewed structures was measured in relation to the standardized point of the middle facet of the calcaneus (mean ± standard deviation and range). The proximity of the middle facet to the posterior tibial tendon was 1.88 ± 2.65 (range 0 to 6.65) mm, to the flexor digitorum longus tendon was 5.34 ± 4.79 (range -3.14 to 12.79) mm, to the flexor hallucis longus tendon was 19.08 ± 4.84 (range 13.04 to 27.31) mm, and to the neurovascular bundle was 21.19 ± 7.84 (range 8.36 to 34.26) mm. At the level of the middle facet, the posterior tibial tendon was the largest tendon, measuring 7.14 ± 2.21 (range 3.31 to 10.23) mm by 2.95 ± 0.88 mm (range 1.86 to 4.24 mm; area 22.37 ± 12.23 mm(2), range 6.16 to 43.38 mm) followed by the flexor digitorum longus tendon at 4.25 ± 1.25 (range 1.74 to 5.95) mm by 2.25 ± 0.96 mm (range 1.41 to 4.79 mm; area 8.88 ± 2.62 mm(2), range 6.12 to 14.52 mm) and flexor hallucis longus tendon at 5.75 ± 2.05 (range 2.27 to 8.91) mm by 2.75 ± 0.82 mm (range 1.35 to 4.13 mm; area 16.81 ± 10.05 mm(2), range 4.81 to 36.80 mm). During dissection for the medial double arthrodesis, one can encounter critical anatomic structures, including artery, vein, nerve, and tendon. Our cadaveric investigation found a mean safe distance of more than 2 cm between the middle facet of the talocalcaneal articulation and the inferiorly located neurovascular bundle using the medial double arthrodesis approach.

Insights Into Patients Questions Over Bunion Treatments: A Google Study.

Background: Approximately 1 in 4 adults will develop hallux valgus (HV). Up to 80% of adult Internet users reference online sources for health-related information. Overall, with the high prevalence of HV combined with the numerous treatment options, we believe patients are likely turning to Internet search engines for questions relevant to HV. Using Google's people also ask (PAA) or frequently asked questions (FAQs) feature, we sought to classify these questions, categorize the sources, as well as assess their levels of quality and transparency. Methods: On October 9, 2022, we searched Google using these 4 phrases: "hallux valgus treatment," "hallux valgus surgery," "bunion treatment," and "bunion surgery." The FAQs were classified in accordance with the Rothwell Classification schema and each source was categorized. Lastly, transparency and quality of the sources' information were evaluated with the Journal of the American Medical Association's (JAMA) Benchmark tool and Brief DISCERN, respectively. Results: Once duplicates and FAQs unrelated to HV were removed, our search returned 299 unique FAQs. The most common question in our sample was related to the evaluation of treatment options (79/299, 26.4%). The most common source type was medical practices (158/299, 52.8%). Nearly two-thirds of the answer sources (184/299; 61.5%) were lacking in transparency. One-way analysis of variance revealed a significant difference in mean Brief DISCERN scores among the 5 source types, F(4) = 54.49 (P < .001), with medical practices averaging the worst score (12.1/30). Conclusion: Patients seeking online information concerning treatment options for HV search for questions pertaining to the evaluation of treatment options. The source type encountered most by patients is medical practices; these were found to have both poor transparency and poor quality. Publishing basic information such as the date of publication, authors or reviewers, and references would greatly improve the transparency and quality of online information regarding HV treatment. Level of Evidence: Level V, mechanism-based reasoning.

Destabilization of phospholipid model membranes by YplA, a phospholipase A2 secreted by Yersinia enterocolitica.

Yersinia enterocolitica produces a virulence-associated phospholipase A(2) (YplA) that is secreted via its flagellar type-III secretion apparatus. When the N-terminal 59 amino acids of YplA are removed (giving YplA(S)), it retains phospholipase activity; however, it is altered with respect to the apparent kinetics of hydrolysis using fluorescent phospholipid substrates in micellar form. To explore the physical properties of YplA more carefully, Langmuir phospholipid monolayers were used to study the association of YplA with biological membranes. YPlA and YplA(S) both associate with Langmuir monolayers, but YplA(S) appears to interact better at low initial lipid densities while YplA interacts better at higher densities. This may indicate that the N-terminus of YplA has a role in mediating its initial interaction with compact cellular membranes, which is consistent with spectroscopic observations that fluorescein-labeled YplA may interact more readily with the nonpolar region of liposomes than does YplA(S).

The plantar plate of the first metatarsophalangeal joint: an anatomical study.

The plantar plate of the first metatarsophalangeal (MP) joint is a critical structure of the forefoot that has been identified as a major stabilizer within the capsuloligamentous complex. Many studies have clarified and documented the anatomy of the lesser toe MP plantar plates, but few have looked closely at the anatomy of the first MP joint. Ten cadaveric specimens were examined to identify and document the objective anatomic relationship of the plantar plate, tibial sesamoid, and surrounding osseus structures. The average distance of the plantar plate distal insertion from the joint line into the proximal phalanx was 0.33 mm. The plantar plate was inserted into the metatarsal head on average 17.29 mm proximal from the joint line. The proximal aspect of the sesamoid was 18.55 mm proximal to the distal attachment of the plantar plate to the phalanx. The distal aspect of the sesamoid averaged 4.69 mm away from the distal attachment into the proximal phalanx. The footprint of the distal plate insertion was on average 6.33 mm in length in the sagittal plane. The authors hope that these objective data measures can aid in the understanding and subsequent surgical repair of this important forefoot structure.

Management of the recurrent deformity in a flexible foot following failure of tendon transfer: is arthrodesis necessary?

Recurrent deformity in the adult flatfoot following previous tendon transfer represents a challenging treatment dilemma for even the most experienced foot and ankle surgeon. The evaluation must be comprehensive, resulting in a clear understanding of the extent to which previous surgical procedures either failed to address the deformity initially or led to progressive recurrence. Particularly in younger, more high-demand patients, every effort to preserve normal joint mechanics while alleviating pain and restoring functional alignment must be made. LCL coupled with MDCO and a comprehensive medial soft tissue reconstruction represents a joint-sparing modality for approaching even the most challenging flexible flatfoot deformities. Care to avoid overcorrection, particularly with a double calcaneal osteotomy, must be taken. In the presence of progressive degenerative changes or patient factors such as morbid obesity and advanced age, hindfoot arthrodesis, particularly realignment subtalar joint arthrodesis, provides a technically straightforward, predictable means of achieving a pain-free plantigrade foot. Talonavicular arthrodesis and double arthrodesis, although reliable means of achieving pain relief and functional alignment, do sacrifice considerably more hindfoot motion and are likely more appropriately reserved for elderly, low-demand patients or those with more severe fixed deformities.

Purification and characterization of two active derivatives of recombinant YplA, a secreted phospholipase from Yersinia entercolitica.

The virulence-associated phospholipase of Yersinia enterocolitica (YplA), which is secreted by a flagellar type III secretion system, was cloned and purified for structure-function analysis using a His(6)-tag expression system. Two versions of YplA have been proposed on the basis of two potential initiating methionine residues. The longer derivative possesses 59 additional amino acids at its N-terminus and appears to represent the native form of YplA; however, the shorter recombinant protein possesses enhanced activity in vitro. Both recombinant YplA derivatives are highly active as type-A(2) phospholipases and possess similar physical properties. Based on type III secretion substrates from other gram-negative bacteria, the N-terminus of YplA is probably required as a secretion signal; however, differences in the time-based activity of these two recombinant enzymes, the N-terminus of YplA may also have a regulatory function.