Arterial anatomy of the tibialis posterior tendon

Tibial Retro-Malleolar Groove Morphology in Patients With Posterior Tibialis Tendon Dysfunction

The posterior tibial tendon is a gliding tendon which courses around the medial malleolus and fails in posterior tibialis tendon dysfunction (PTTD) leading to a flat foot deformity. Distal tibial bone spurs have been identified as a secondary sign of PTTD although they have not been quantified in detail. The aim of this study was to assess the association of tendon dysfunction with the bony morphology of the tibial retro-malleolar groove. We performed a retrospective review of the clinical presentation, plain radiographs, and 103 magnetic resonance imaging (MRI) scans in 82 consecutive patients with PTTD compared with a non-PTTD group. We carried out a quantitative and qualitative assessment of the presence of plain radiographic bone spurs, stage of PTTD and MRI imaging of the morphology of the tibial bony malleolar groove. Plain radiographic bone spurs, as a secondary sign of PTTD, were present in 21.3% of ankle radiographs. MRI bone spurs were identified in 26/41 (63.4%) for all high-grade partial and complete tears and 7/41 (17.1%) for isolated complete tears compared with only 3.9% of the non-PTTD group. There was a significant association between the presence of bone spurs on MRI imaging and high-grade partial and complete tibialis posterior tears (p < .001; odds ratio of 4.98). Eleven of 103 (10.7%) of spurs were large and in 4/103 (3.9%) were substantial enough to create a tunnel-like hypertrophic groove not previously reported. There is variation in the bony structure of the malleolar groove in PTTD not observed in the non-PTTD group. Further investigation over time may elucidate whether the groove morphology may lead to mechanical attrition of the tibialis posterior tendon and contribute to failure of healing and progressive tendon degeneration.

Approach to the Ankle in Adult Acquired Flatfoot Deformity

Adult acquired flatfoot is a progressive deformity of the foot and ankle, which frequently becomes increasingly symptomatic. The posterior tibial tendon is most commonly associated with the deformity. A targeted physical examination with plain film radiographs is the recommended initial assessment, which will further guide a physician toward procuring more advanced imaging or toward surgical intervention. In this chapter the authors review the current literature of their approach to the treatment of the ankle in end stage of adult acquired flatfoot deformity.

Presurgical Perspective and Postsurgical Evaluation of Non-Achilles Tendons of the Ankle and Retinaculum

The vast majority of non-Achilles ankle tendinopathies are related to overuse. This article discusses the clinical aspect, imaging appearance, and management of tendinopathies of the lateral, medial, and the anterior compartments with a focus on presurgical perspective and postsurgical evaluation.

The tibialis posterior tendon footprint: an anatomical dissection study

BACKGROUND

The tibialis posterior tendon (TPT) is the main dynamic stabilizer of the medial longitudinal arch of the foot. Especially in adult acquired flatfoot deformity (AAFD) the TPT plays a detrimental role. The pathology and function of the tendon have been extensively investigated, but knowledge of its insertional anatomy is paramount for surgical procedures. This study aimed to analyze the complex distal footprint anatomy of the TPT.

METHODS

Forty-one human anatomical specimens were dissected and the distal TPT was followed to its bony footprints. After tendon removal the footprints were marked with ink. Standardized photographs were taken and consecutively analyzed by digital imaging measurements. Footprint length, width, area of insertion, location, and shape was studied regarding the main insertion at the navicular bone.

RESULTS

All specimens had the main TPT insertion at the navicular bone (41/41, 100%). Sixty-three percent of navicular TPT insertions were located at the plantar aspect. The mean navicular footprint measured 12.1 mm × 6.9 mm in length and width, respectively. The tendon further spread into several slips which anchored the tibialis posterior deep in the plantar arch. TPT insertions were highly variable with an involvement of up to eight distinct bony footprints in the mid- and hindfoot. The second most common additional footprint was the lateral cuneiform (93% of dissected feet), followed by the medial cuneiform (80%), the metatarsal bases [1-5] (80%), the cuboid (46%), the intermediate cuneiform (19%), and the calcaneus (12%).

CONCLUSIONS

The present study adds to current knowledge on the footprint anatomy of the TPT. Based on the findings of this study we advocate a plantar location of flexor digitorum longus tendon transfer in flexible AAFD in order to restore the anatomical lever and insertion of the TPT.

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. Online supplemental material is available for this article. ^©RSNA, 2019.

Consideration of medial anatomical structures at risk when placing quadricortical syndesmotic fixation: A cadaveric study

BACKGROUND

Surgical fixation of syndesmotic instability using quadricortical fixation, whether screws or suture-button devices, places structures on the medial side of the tibia at iatrogenic risk. This study aims to radiographically map the anatomic course of structures on the medial aspect of the distal tibia to be able to at-risk zones (ARZs) for syndesmotic fixation.

METHODS

Eighteen fresh-frozen cadaveric ankle specimens were dissected. The saphenous neurovascular bundle (SNVB) and the posterior tibial tendon (PTT) were identified and marked with copper wiring. Standardized and calibrated lateral radiographs of the distal tibia and fibula were analyzed using a grid system consisting of 3 columnar zones from anterior to posterior and five 1-cm rows to chart the anatomic course of the SNVB and the PTT.

RESULTS

The SNVB was located in the more anterior zones (1, 2, or anterior to Zone 1) in 97.3% of specimens. The SNVB traversed from posterior to anterior as it descended proximal to distal. The PTT was found in Zone 3 (most posterior zone) for all specimens. The PTT was noted to pass behind (radiographically overlap) the tibia in 83.3% (15 of 18) of specimens between 1 and 3 cm above the tibiotalar joint.

CONCLUSIONS

Placement of quadricortical syndesmotic fixation places structures on the medial ankle at risk. The SNVB is at considerable risk along the anterior course of the distal tibial while the PTT is only at risk in zone 3 at the distal extent of the tibia.

Adult-Acquired Flatfoot Deformity

Adult-acquired flatfoot deformity (AAFD) comprises a wide spectrum of ligament and tendon failure that may result in significant deformity and disability. It is often associated with posterior tibial tendon deficiency (PTTD), which has been linked to multiple demographic factors, medical comorbidities, and genetic processes. AAFD is classified using stages I through IV. Nonoperative treatment modalities should always be attempted first and often provide resolution in stages I and II. Stage II, consisting of a wide range of flexible deformities, is typically treated operatively with a combination of soft tissue procedures and osteotomies. Stage III, which is characterized by a rigid flatfoot, typically warrants triple arthrodesis. Stage IV, where the flatfoot deformity involves the ankle joint, is treated with ankle arthrodesis or ankle arthroplasty with or without deltoid ligament reconstruction along with procedures to restore alignment of the foot. There is limited evidence as to the optimal procedure; thus, the surgical indications and techniques continue to be researched.

The Arterial Anatomy of the Lateral Ligament Complex of the Ankle: A Cadaveric Study

BACKGROUND

Ankle sprains are the most common musculoskeletal injury in the United States. Chronic lateral ankle instability can ultimately require operative intervention to decrease pain and restore stability to the ankle joint. There are no anatomic studies investigating the vascular supply to the lateral ankle ligamentous complex.

PURPOSE

To define the vascular anatomy of the lateral ligament complex of the ankle.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Thirty pairs of cadaveric specimens (60 total legs) were amputated below the knee. India ink, followed by Ward blue latex, was injected into the peroneal, anterior tibial, and posterior tibial arteries to identify the vascular supply of the lateral ligaments of the ankle. Chemical debridement was performed with 8.0% sodium hypochlorite to remove the soft tissues, leaving casts of the vascular anatomy intact. The vascular supply to the lateral ligament complex was then evaluated and recorded.

RESULTS

The vascular supply to the lateral ankle ligaments was characterized in 56 specimens: 52 (92.9%) had arterial supply with an origin from the perforating anterior branch of the peroneal artery; 51 (91.1%), from the posterior branch of the peroneal artery; 29 (51.8%), from the lateral tarsal branch of the dorsalis pedis; and 12 (21.4%), from the posterior tibial artery. The anterior branch of the peroneal artery was the dominant vascular supply in 39 specimens (69.6%).

CONCLUSION

There are 4 separate sources of extraosseous blood supply to the lateral ligaments of the ankle. In all specimens, the anterior talofibular ligament was supplied by the anterior branch of the peroneal artery and/or the lateral tarsal artery of the dorsalis pedis, while the posterior talofibular ligament was supplied by the posterior branch of the peroneal artery and/or the posterior tibial artery. The calcaneofibular ligament received variable contributions from the anterior and posterior branches of the peroneal artery, with few specimens receiving a contribution from the lateral tarsal or posterior tibial arteries.

CLINICAL RELEVANCE

Understanding the vascular anatomy of the lateral ligament complex is beneficial when considering surgical management and may provide insight into factors that lead to chronic instability.

Tendonitis and Tendinopathy: What Are They and How Do They Evolve?

The development of tendinitis and tendinopathy is often multifactorial and the result of both intrinsic and extrinsic factors. Intrinsic factors include anatomic factors, age-related factors, and systemic factors, whereas extrinsic factors include mechanical overload and improper form and equipment. Although tendinitis and tendinopathy are often incorrectly used interchangeably, they are in 2 distinct pathologies. Due to their chronicity and high prevalence in tendons about the ankle, including the Achilles tendon, the posterior tibialis tendon, and the peroneal tendons, tendinitis and tendinopathies cause significant morbidity and are important pathologies for physicians to recognize.

Arterial Anatomy of the Posterior Tibial Nerve in the Tarsal Tunnel

BACKGROUND

Both vascular and compression etiologies have been proposed as the source of neurologic symptoms in tarsal tunnel syndrome. Advancing the understanding of the arterial anatomy supplying the posterior tibial nerve (PTN) and its branches may provide insight into the cause of tarsal tunnel symptoms. The purpose of this study was to describe the arterial anatomy of the PTN and its branches.

METHODS

Sixty adult cadaveric lower extremities (thirty previously frozen and thirty fresh specimens) were amputated distal to the knee. The vascular supply to the PTN and its branches was identified, measured, and described macroscopically (the thirty previously frozen specimens, prepared using a formerly described debridement technique) and microscopically (the thirty fresh specimens, processed using the Spälteholz technique).

RESULTS

On both macroscopic and microscopic evaluation, the PTN and the medial and lateral plantar nerves were observed to have multiple entering vessels within the tarsal tunnel. On microscopic evaluation, a vessel was observed to enter the nerve at the bifurcation of the PTN into the medial and lateral plantar nerves in twenty-two (73%) of the thirty specimens. There was a significant difference (p < 0.05) in vascular density between the PTN and each of its branches.

CONCLUSIONS

The abundant blood supply to the PTN and its branches identified in this study is consistent with observations of other peripheral nerves. This rich vascular network may render the PTN and its branches susceptible to nerve compression related to vascular congestion. The combination of vascular and structural compression may also elicit neurologic symptoms.

CLINICAL RELEVANCE

Advancing the understanding of the arterial anatomy supplying the PTN and its branches may provide insight into the cause and treatment of tarsal tunnel syndrome.