Rustin Reeves

An attachment-based description of the medial collateral and spring ligament complexes.

Background: Anatomy of the medial collateral and spring ligament complexes has been the cause of confusion. The anatomic description is highly dependent on the source studied and little agreement exists between texts. In addition, inconsistent nomenclature has been used to describe the components. This study attempted to clarify confusion through the creation of a 3D ligament map using attachment-based dissection. Methods: Nine fresh foot and ankle specimens were observed. The medial collateral ligament and spring ligament complexes were dissected using their attachment sites as a guide to define individual components. Each component’s perimeter and thickness was measured and each bony attachment was mapped using a microscribe 3D digitizer. Results: Five components were identified contributing to the ligament complexes of interest: the tibiocalcaneonavicular, superficial posterior tibiotalar, deep posterior tibiotalar, deep anterior tibiotalar, and inferoplantar longitudinal ligaments. The largest component by total attachment area was the tibiocalcaneonavicular ligament followed by the deep posterior tibiotalar ligament. The largest ligament surface area of attachment to the tibia and talus was the deep posterior tibiotalar ligament. The largest attachment to the navicular and calcaneus was the tibiocalcaneonavicular ligament, which appeared to function in holding these bones in proximity while supporting the head of the talus. Conclusion: By defining complex components by their attachment sites, a novel, more functional and reproducible description of the medial collateral and spring ligament complexes was created. Clinical Relevance: The linear measurements and 3D maps may prove useful when attempting more anatomically accurate reconstructions.

Association of Hindfoot Ligament Tears and Osteochondral Lesions

Background: This study aimed to identify the prevalence of ligament and joint surface anatomy variants, ligament tears, and osteochondral lesions (OCLs) in the hindfoot. These data were used to identify associations between anatomic variants or ligament tears and OCLs. Methods: Seventy-two cadaver hindfoot specimens were examined. Hindfoot ligament presence, number of ligament fascicles, variable ligament attachment sites, ligament tears, presence of joint facets, variable joint surface shape, and the location and grade of OCLs were identified in each specimen. The data were analyzed for significant associations between variables. Results: Fourteen of the 30 studied ligaments were always present and 14 had variable number of fascicles. The lateral talocalcaneal and dorsolateral calcaneocuboid ligaments had varying positional attachments. Osteochondral lesions were present in 86% of specimens with the majority in the talocrural joint. Of the 235 lesions identified, 31 were grade 3 or above. Ligament tears occurred in 2% of all ligaments observed. Tears in the lateral talocalcaneal, medial calcaneocuboid, and dorsolateral calcaneocuboid ligaments were associated with an increased number of hindfoot OCLs. Conclusion: We demonstrated the prevalence of morphologic ligament and joint surface variants, ligament tears, and osteochondral lesions in the hindfoot. Tears in ligaments stabilizing the calcaneocuboid joint were implicated in an increase in hindfoot joint damage. Clinical Relevance: We believe anatomic studies can be used to clarify the association between traumatic injuries and their sequelae.

Anomalous peroneus (fibularis) longus muscle: An atypical insertion and incomplete distal tendon

The peroneus (fibularis) longus muscle occurs in the lateral compartment of the leg, originating on the head and proximal shaft of the fibula. The muscle belly courses distally into a tendon that runs posterior to the lateral malleolus. The tendon continues posterior to the peroneal trochlea at which point it courses obliquely forward along the lateral surface of the calcaneus. Once reaching the cuboid, the tendon turns medially along the gliding facet of the cuboid and runs obliquely in the plantar tunnel formed by the long plantar ligament. The tendon ultimately inserts into the base of the first metatarsal and the medial cuneiform. Because of the oblique course of the muscle to the opposing side of the foot, the primary action of the peroneus longus is to evert and plantarflex the foot (Sarrafian, 1993; Gray et al., 2005). During the dissection of a 76-year-old male cadaver, the peroneus longus muscle with unusual insertions was identified bilaterally. The subject passed away from pneumonia and had no evidence of lower extremity surgery and appeared grossly normal. Both peroneus longus muscles originated from their typical locations on the head and proximal shaft of the fibula. The peroneus longus muscle continued distally in the expected course until reaching the cuboidal tuberosity where the peroneus longus separates from the peroneus brevis. At this point, there appeared an amalgam of thick fibrous tissue (fibrous expansion) with strong attachments to the cuboid and base of the fifth metatarsal (Fig. 1A and 1B). The fibrous expansion was carefully disconnected from its attachments in an attempt to identify the underlying peroneus longus tendon. Once disconnected, it was apparent that the peroneus longus tendon was continuous with the fibrous expansion. Beneath the fibrous expansion, the lateral and inferior surface of the cuboid was rough (Fig. 1C); not the typical gliding surface for the peroneus longus tendon. The tendon did not contain a sesamoid bone as it turned under the plantar surface of the foot as is often observed. The superficial fibers of the long plantar ligament were divided to identify the rest of the peroneus longus tendon in the plantar tunnel. Within the tunnel, atypical fibrous bands were identified (Fig. 1B–1D). Although the tissue had fiber organization suggestive of the peroneus longus tendon, the tissue had continuous attachments throughout the tunnel and was folded upon itself in numerous locations, preventing the typical sliding function of the tendon. The distal attachment of the fibrous tissue was typical for the peroneus longus tendon on the base of the first metatarsal and medial cuneiform. With the attachment of the peroneus longus muscle on the cuboid and base of the fifth metatarsal, the peroneus longus muscle would be expected to act similarly to the peroneus brevis muscle. Eversion would be maintained. The extensive attachments of the tendon at the cuboid and fifth metatarsal and throughout the course of the plantar tunnel would prevent the gliding of the tendon through the tunnel and around the lateral surface of the foot despite normal firing of the muscle. Therefore, the support of the longitudinal and transverse arches during toe-off as well as the stabilization of the first ray while on the ground would likely be diminished. Plantar flexion would also be diminished, but one would expect this action to be adequate as there were numerous plantarflexing muscles with usual morphology in this specimen. Numerous variations of the peroneal muscles have been described. Many of the variants describe accessory peroneal muscles such as the peroneus digiti quinti and the peroneus quartus (Wood, 1867; Ledouble and Marey, 1897; Hammerschlag and Goldner, 1989; Sobel et al., 1990; Trono et al., 1999; Moroney and Borton, 2004). The peroneus

A Cadaveric Study on the Surface Projection of the Dorsal Scapular Nerve

Background: Dorsal scapular nerve (DSN) syndrome is often associated by dull or aching pain along the medial border of the scapula that can radiate to the lateral aspect of the upper limb. The primary cause of this syndrome is due to the impingement or entrapment of this nerve at the middle scalene muscle. The purpose of this study is to identify the surface projection of the DSN relative to the middle scalene muscle by using the transverse plane of the laryngeal prominence and the posterior border of the sternocleidomastoid (SCM) muscle as reference points along with approximating the nerves location using thumb interphalangeal joint (IPJ) width. Methods: The surface location of the DSN was examined in 10 embalmed adult cadavers. The posterior border of the SCM muscle was palpated and outlined along with the transverse plane of the laryngeal prominence. A resin dye was injected at a distance of 2.08 cm (~ 1 thumb IPJ width) medial to the intersection of the posterior border of the SCM and the transverse plane of the laryngeal prominence. Dissections were performed to reveal and record the location of the dye. The distance between the location of the dye to the DSN was also measured. Results: The overall accuracy of the injection study revealed that the scalene muscles were consistently located. Specifically, 50% of the injections were found at the middle scalene muscle, 20% was between the anterior and middle scalene muscles, 10% at the anterior scalene muscle, 10% between the middle and posterior scalene muscles, and 10% was located at the posterior scalene muscle. Conclusion: This investigation will provide clinicians a useful and convenient method to determine the surface projection of the DSN at its entrapment site for the purpose of diagnosis and therapeutic treatment.