Anatomy of the Ankle and Subtalar Joint Ligaments: What We Do Not Know About It?

Understanding of the ankle and subtalar joint ligaments is essential to recognize and manage foot and ankle disorders. The stability of both joints relies on the integrity of its ligaments. The ankle joint is stabilized by the lateral and medial ligamentous complexes while the subtalar joint is stabilized by its extrinsic and intrinsic ligaments. Most injuries to these ligaments are linked with ankle sprains. Inversion or eversion mechanics affect the ligamentous complexes. A profound knowledge of the ligament's anatomy allows orthopedic surgeons to further understand anatomic or nonanatomic reconstructions.

Outcomes of Combined Posterior Tibial Tendon Tendoscopy and Medializing Calcaneal Osteotomy for Stage IA Progressive Collapsing Foot Deformity.

BACKGROUND: Posterior tibial tendon (PTT) tendoscopy and medializing calcaneal osteotomy (MCO) are among the available techniques for patients presenting with symptomatic flexible hindfoot valgus (stage IA) progressive collapsing foot deformity (PCFD). The aim of this study was to determine clinical and radiographic outcomes of combined PTT tendoscopy and MCO for patients presenting with symptomatic stage IA PCFD. METHODS: A retrospective cohort study was performed in order to determine clinical and radiographic outcomes of 30 combined PTT tendoscopies and MCO on 27 patients presenting with symptomatic stage IA PCFD, with a minimum follow-up of 24 months. Patient satisfaction was assessed at last available follow-up as very satisfied, satisfied, and unsatisfied. Clinical assessment was performed evaluating preoperative and last available follow-up visual analog scale for pain (VAS-P), Foot and Ankle Outcome Score (FAOS), and the 36-Item Short Form Health Survey (SF-36). Magnetic resonance imaging (MRI) was performed preoperatively on all patients. Standard weightbearing anteroposterior, lateral, and long axial view radiographs of the foot and ankle were taken preoperatively, immediate postoperatively, at 6 weeks, 3 months, 6 months, 1 year postoperatively, and last follow-up evaluation available for each patient. RESULTS: The mean follow-up was 38.6 (range, 26-62) months. We registered 27 very satisfied, 1 satisfied, and 2 unsatisfied patients. There was statistically significant improvement on all clinical scores (VAS-P, FAOS and SF-36), as well as on lateral talo-first metatarsal and hindfoot alignment angles. We found low-grade PTT tears in 5 patients (16.67%) in whom preoperative MRI documented PTT tenosynovitis alone. CONCLUSION: We found that combined PTT tendoscopy and MCO provide significant clinical and radiographic improvement for patients presenting with symptomatic stage IAB PCFD. PTT tendoscopy should be considered in the treatment of all surgically addressed flexible valgus feet as it detects tendon tears which are frequently missed on an MRI. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Radiological and Anatomical Evaluation of First Metatarsal Pronation in Hallux Valgus Deformity: A Comparison Between Three Different Methods.

A frontal plane metatarsal rotational (pronation) has been documented in a high percentage of hallux valgus patients. Pathoanatomical concepts leading to pronation are still debated. Nevertheless, there is no consensus on how to measure this component of the deformity. The aim of the present study was to compare three commonly used radiographic methods to measure the frontal plane deformity in hallux valgus deformity, such as 1. Round sign of the lateral edge of the first metatarsal head on anterior-posterior radiograph, 2. Non-weightbearing CT-scan and 3. Bernard's axial projection of the first metatarsal head. Afterwards, feet were dissected, and a direct measurement of the pronation was done. Our data showed that alpha angle measurements made through the Bernard's axial projection were closer with those obtained during the dissection compared to those made through the CT-scan. The main finding of our study is that osteoarthritic changes at the metatarso-sesamoid joint play an important role in severe hallux valgus cases. The proposed radiographic methods allow surgeons to verify whether rotation can be corrected during Hallux Valgus procedures and to determine which procedure may be the best for each patient.

Complications after total ankle arthroplasty- A systematic review.

BACKGROUND: Total ankle arthroplasty was developed as an alternative option to ankle arthrodesis in patients with end-stage ankle osteoarthritis. Multiple trials have assessed the outcomes of ankle arthroplasty, but complication risk or relative effectiveness is not systematized in literature. AIM: Review complications of new designs of total ankle arthroplasty and the relationship between their severity and failure rates. METHODS: We reviewed complications and revision rates of prospective studies of primary total ankle arthroplasty that included more than 50 patients and with minimum 2 years follow-up. RESULTS: We included 22 studies (4412 ankles, median age of 61.9 years) with an adjusted mean follow-up time of 66.6 ± 40.9 months. The adjusted mean complication rate was 23.7 % (2.4-52 %), mostly high-grade complications (35.6 %). We found a statistically significant positive correlation between high- and medium-grade complications and revision rates. CONCLUSION: Patient selection is crucial to successfully treat end-stage ankle osteoarthritis. Further multicenter clinical trials with consistent reporting of complications are warranted.

Anatomy of the tibial nerve in relation to the tarsal tunnel: A cadaveric study.

BACKGROUND: Tarsal tunnel syndrome (TTS) is typically caused by an anatomical variant or mechanical compression of the tibial nerve (TN) with variable success after surgical treatment. METHOD: 40 lower-leg specimens were obtained. Dissections were appropriately conducted. Extremities were prepared under formaldehyde solution. The tibial nerve and branches were dissected for measurements and various characteristics. RESULTS: The flexor retinaculum had a denser consistency in 22.5% of the cases and the average length was 51.9 mm. The flexor retinaculum as an independent structure was absent and 77.2% of cases as an undistinguished extension of the crural fascia. The lateral plantar nerve (LPN) and abductor digiti minimi (ADM) nerve shared same origin in 80% of cases, 34.5% bifurcated proximal to the DM (Dellon-McKinnon malleolar-calcaneal line) line 31.2% distally and 34.3% at the same level. CONCLUSION: Understanding the tibial nerve anatomy will allow us to adapt our surgical technique to improve the treatment of this recurrent pathology.

Osteosynthesis or primary arthrodesis for displaced intra-articular calcaneus fractures Sanders type IV - A systematic review.

BACKGROUND: Displaced intra-articular calcaneus fractures (DIACF) Sanders type IV represent a challenge in its management and questions remain about the best treatment option available. This study aimed to compare the outcomes of primary subtalar arthrodesis (PSTA) and osteosynthesis in these fractures. METHODS: Studies concerning DIACF Sanders type IV, from 2005 to 2020 were systematically reviewed. Only studies evaluating functional outcomes with American Orthopaedic Foot & Ankle Society ankle-hindfoot (AOFAS) score were admitted allowing for results comparison. RESULTS: In total, 9 studies met the inclusion criteria. These reported on the results of 142 patients, from which 41 submitted to PSTA and 101 to osteosynthesis, with an average follow-up period over 2 years. We found a significant moderate negative correlation between the reported AOFAS score and the Coleman Methodology Score obtained. Late subtalar arthrodesis was 13.63% of the total osteosynthesis performed. CONCLUSIONS: Clinical outcomes after PSTA and osteosynthesis, for the treatment of Sanders type IV fractures, do not seem very different, yet careful data interpretation is crucial. Additional powered randomized controlled trials are necessary to assess which surgical strategy is better.

Current Concepts on Subtalar Instability.

Subtalar instability remains a topic of debate, and its precise cause is still unknown. The mechanism of injury and clinical symptoms of ankle and subtalar instabilities largely overlap, resulting in many cases of isolated or combined subtalar instability that are often misdiagnosed. Neglecting the subtalar instability may lead to failure of conservative or surgical treatment and result in chronic ankle instability. Understanding the accurate anatomy and biomechanics of the subtalar joint, their interplay, and the contributions of the different subtalar soft tissue structures is fundamental to correctly diagnose and manage subtalar instability. An accurate diagnosis is crucial to correctly identify those patients with instability who may require conservative or surgical treatment. Many different nonsurgical and surgical approaches have been proposed to manage combined or isolated subtalar instability, and the clinician should be aware of available treatment options to make an informed decision. In this current concepts narrative review, we provide a comprehensive overview of the current knowledge on the anatomy, biomechanics, clinical and imaging diagnosis, nonsurgical and surgical treatment options, and outcomes after subtalar instability treatment.

Outcomes of Posterior Arthroscopic Subtalar Arthrodesis for Medial Facet Talocalcaneal Coalition.

BACKGROUND: Medial facet talocalcaneal coalition can be a painful condition. This study aimed to determine clinical and radiographic outcomes of posterior arthroscopic subtalar arthrodesis (PASTA) for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, with a minimal follow-up of 18 months. METHODS: Between June 2017 and July 2019, this procedure was performed on 8 feet (8 patients; mean age, 55 [42-70] years; mean BMI, 29.8 [24.4-45.0] kg/m2). Clinical assessment was performed using Visual Analog Scale for Pain (VAS-P), Foot and Ankle Outcome Score (FAOS) and the 36-Item Short-Form Health Survey (SF-36). Patient satisfaction was assessed at the last available follow-up as "very satisfied", "satisfied" or "unsatisfied". Radiographic analysis was performed using plain radiography, computed tomography (CT) scan and magnetic resonance imaging (MRI). The primary outcome was to determine both clinical and radiographic outcomes. RESULTS: The mean follow-up was 25.1 (18.2-34.2) months. The authors found statistically significant improvement on all clinical scores (VASP-P, FAOS and SF-36). They registered 6 "very satisfied" patients, 2 "satisfied" patients and no "unsatisfied" patient. Fusion of the subtalar joint was observed in all patients by 12 weeks and in 5 of them as soon as 8 weeks postoperatively (mean, 9.5 [8-12] weeks). There were no cases of delayed fusion or nonunion of the subtalar joint, superficial or deep infection, neurovascular damage, thromboembolic event, screw breakage, need for hardware removal or revision surgery. CONCLUSION: This study found that PASTA is a safe and reliable technique for adult patients presenting with symptomatic medial facet talocalcaneal coalition and normal hindfoot alignment, demonstrating and maintaining clinical improvement at an average follow-up of 2 years. LEVEL OF EVIDENCE: Level IV, case series.

Complications on Percutaneous Hallux Valgus Surgery: A Systematic Review.

Lately there has been a growing interest in the use of percutaneous surgery for the correction of hallux valgus (HV). The purpose of the present study was to systematically review the published data about this topic and establish the efficacy and safety, stressing the complication rates found on this percutaneous technique. A systematic review of the literature available in PubMed was performed. The radiological and clinical outcomes were evaluated as well as complication rates. A total of 16 studies were included and 1157 procedures reported for percutaneous HV on 1246 patients. The mean angle correction of HV deformity improved postoperatively. Reported complications vary among the studies. The highest complication rate was joint stiffness in 18.47% of cases, followed by HV recurrence and shortening of M1, both in 15.2%, material intolerance in 10.1%, osteoarthritic changes in 9.1%, infection in 7.6%, and transfer metatarsalgia in 5.4%. There is a lack of randomized control trials and insufficient comparative case control studies to assess whether one technique is more effective than another or if the percutaneous surgery is recommended rather than open surgery with respect to complications.

Posteroinferior tibiofibular ligament - A cadaveric study.

BACKGROUND: Ankle injuries are one of the most common musculoskeletal disorder. The purpose of this study was to analyze and describe the detailed anatomical arrangement and relationship of posterior ligaments of the ankle, especially de posteroinferior tibiofibular ligament (PITFL) and intermalleolar ligament (IML). Controversy exists in the previous literature regarding their morphology and denomination, as well as the relation with ankle injuries including posterior soft tissue impingement syndrome. METHODS: Seventeen fresh-frozen cadaveric feet were used. The origins, insertions, ligament lengths, orientations with respect to relevant bony landmarks of the PITFL were evaluated. RESULTS: PITFL was present in all anatomical specimens. It was formed by two independent components, the superficial and deep fibers. Their dimensions vary widely between specimens. The IML was located between the deep PITFL and posterior talofibular ligament. The shape varied from a thin fibrous band to a thick cordlike structure. The IML was evident in 82.4% of the ankles. In 28.6% of the cases, the posterior intermalleolar ligament was split into two bundles in the fibular insertion. In 14 ankles, three slips were found. CONCLUSION: Given the frequency of injury and increasing necessity for surgical intervention, a more comprehensive anatomic knowledge of the different ligaments is warranted, provide clinically pertinent quantitative data and improve the treatment of these lesions.

The vascularization of the peroneal tendons: An anatomic study.

BACKGROUND: Arterial vascularization is intimately related to the peroneal tendon ruptures. Our purpose is to describe the vascular anatomy of peroneal tendons and assess differences in the vascularization patterns between peroneus brevis tendon (PBT) and peroneus longus tendon (PLT). METHODS: Anatomical study of 22 cadaveric lower extremities. We exposed tendons' vascularization by injecting latex. To systematize the vascular description, we considered four anatomical regions in the PBT and six in the PLT. RESULTS: Vascularization was supplied by the peroneal, anterior tibial and lateral plantar arteries and from the deep plantar arch through the vincula connecting the tendons. No avascular areas were found in the PLT. 22.7% of specimens had avascular areas in the PBT. Two visual vascularization patterns were found (arcuate and weblike). Increasing age and a web-like vascularization were associated with a lower number of blood vessels at the tendons' post malleolus area. CONCLUSION: Peroneal tendons are well vascularized throughout their course, running through a common vincula, with vascularization provided by various arteries. Avascular areas were observed in the PBT, but none at the PLT.

Outcomes of open "crown" type v. percutaneous Bunnell type repair of acute Achilles tendon ruptures. Randomized control study.

BACKGROUND: The optimal treatment of acute Achilles tendon ruptures (AATR) is still under debate. The purpose of this study was to evaluate outcomes of open repair comparing with percutaneous procedure for AATR. METHODS: 100 patients with AATR were randomized in two groups: open "crown" type (group A) and percutaneous Bunnell type repair (group B). 87 patients were available for the mean follow up of 27months RESULTS: No statistically significant difference was observed between groups in ATRS score, leg circumference, single heel rise, Achilles resting angle, time back to work and sports and overall patient satisfaction. Percutaneous technique was much faster. Overall 13 complications occurred in both groups (5 and 8 respectively). No deep infection occurred, no revisions were needed. CONCLUSIONS: Both techniques showed to be effective and safe when using absorbable suture material with a high patient satisfaction and a low complication rate, but percutaneous repair was significantly faster.

Varus talar tilt combined with an internal rotation pivot stress assesses the supination instability vector in lateral ankle ligaments' injury - cadaver study.

BACKGROUND: The lack of consensus on the relevance of the varus talar tilt test (VTTT) might be due to the divergence between the insufficiency vector of lateral ankle instability and the direction of this clinical test. Our hypothesis is that the VTTT is more accurate to diagnose lateral ankle ligaments rupture when it's applied with a pre-positioning of the foot in internal rotation (IR). METHODS: We compared, in 12 cadaver ankles, the varus opening during a classic VTTT with the same test starting in an IR pivot, using a new arthrometer. RESULTS: The classic VTTT caused a 13° tilt after ATFL section and 23,8° after ATFL and CFL section. The application of a VTTT with an IR prepositioning caused a 21,2° tilt after ATFL section (p = 0,002) and 29,5° after ATFL and CFL section (p = 0,006). CONCLUSION: The VTTT is better to identify lateral ankle ligaments' insufficiency when it's applied with a pre-positioning of the foot in internal rotation. The resulting vector is similar to the supination trauma.

The Os Peroneum incidence - A cadaveric study.

BACKGROUND: The Os Peroneum (OP) is a small sesamoid bone, which can be found in the Peroneus Longus Tendon (PLT) sheath, near the calcaneocuboid joint. Size and shape variability is quite common as well as a multipartite OP that can be found in some cases. Trying to explore and understand this variability, this study was carried out in order to provide us with answers about the presence and shape of OP in our specimens. METHODS: Twenty cadaveric lower extremities were obtained according to the body donation program of our institution. Dissections were performed to expose the OP (when present) starting proximally at the origin of the PLT and Peroneal Brevis Tendon (PBT) finalizing at the insertion of the PLT in the first metatarsal. RESULTS: In twenty feet, nine distinct OP were found, whilst six feet had a thickening of the tendon. On the remaining five foot, we did not identify an OP. CONCLUSIONS: In this study, 45% of the feet analyzed had an OP. The authors believe the variability of OP prevalence reported in the literature can be associated with differences in its definition.

The calcaneofibular ligament has distinct anatomic morphological variants: an anatomical cadaveric study.

PURPOSE: The purpose of this study was to investigate if the calcaneofibular ligament (CFL) presents morphologic variants and measure the morphometrics of the ligament and its footprints METHODS: An anatomical study of 47 fresh-frozen below-the-knee ankle specimens was performed. Lateral ankle structures were dissected to expose the CFL. Overdissection was avoided to not modify the native morphology. The morphology (number and orientation of CFL bundles) and measurements of CFL insertions were recorded with ankle secured in neutral position. RESULTS: Four distinct morphological-oriented shapes of the CFL were observed. These included single bundle, Y-shape double bundle, V-shape double bundle, and associated with the lateral talocalcaneal ligament. The most frequent CFL morphology observed was the single bundle and the Y-shape double bundle, present in 21 (44.7%) and 13 (27.7%) ankles. The V-shape double bundle and the CFL double bundle associated with the lateral talocalcaneal ligaments were less common, appearing only in eight (17.0%) and five (10.6%) ankles. The CFL length was higher in single bundle and Y-shaped double bundle CFL variants, about 30 mm each. Footprint morphometrics were heterogenous amongst the different CFL variants. CONCLUSION: The CFL presents four distinct morphological-oriented shapes. The double bundle, V-shaped and Y-shaped CFL variants are uncommon and poorly reported in the literature. Their relation to the lateral talocalcaneal ligament and the inferior fascicle of the anterior talofibular ligament requires further research. The CFL morphology provides detailed knowledge of CFL anatomy that can improve diagnostic procedures. Furthermore, this information can fine-tune graft selection and sizing and allow a more precise anatomic placement during surgical reconstruction.

The distance from the peroneal tendons sheath to the sural nerve at the posterior tip of the fibula decreases from proximal to distal.

PURPOSE: The aim of this study is to compare the distance from the peroneal tendons sheath to the sural nerve in different points proximally and distally to the tip of the fibula. METHODS: Ten fresh-frozen lower extremities were dissected to expose the nerves and tendons. Having the posterior tip of the fibula as a reference, the distance between the tendons sheath and the sural nerve was measured in each point with a tachometer with three independent different observers. Two measures were taken distally at 1.5 and 2 cm from fibula tip and 3 measures were performed proximally at 2, 3, and 5 cm from fibula tip. Data were described using means, standard deviations, medians, and minimum and maximum values. RESULTS: The average distance between distance between the fibula tip and sural nerve is 16.6 ± 4.4 mm. The average distance between peroneal tendons sheath and the sural nerve at 5 cm, 3 cm, and 2 cm from the proximal fibular tip was 29.6 ± 3.2 mm, 24.2 ± 3.6 mm, and 19.7 ± 2.7 mm, respectively. The average distance between the peroneal tendons sheath and the sural nerve at 2 cm and 1.5 cm distal to fibular tip was 9.1 ± 3.5 mm and 7.8 ± 3.3 mm, respectively. CONCLUSION: The distance from the peroneal tendons sheath to the sural nerve decreases from proximal to distal. As the distance between the peroneal tendons sheath and the sural nerve decreases from proximal to distal, performing the tendoscopy portal more distally would increase the risk of nerve iatrogenic injury.

Insertional anatomy of peroneal brevis and longus tendon - A cadaveric study.

BACKGROUND: Peroneal Tendon (PT) complex is formed by the Peroneus Longus Tendon (PLT) and Peroneus Brevis Tendon (PBT), their synovial sheath, the superior and inferior retinaculum, and the Os Peroneum (OP). Their insertion is associated with some anatomic variability. Knowing these variants helps to understand the PT pathology and it may support the decision-making concerning the operative approach. The purpose of this study was to assess anatomical variability in PT insertion. METHODS: Twenty fresh-frozen cadaveric feet were used. The lateral part of the ankle, foot and sole were dissected to expose PLT and PBT course and distal insertions. RESULTS: Concerning the PBT, eleven feet had a normal insertion in the base of the fifth metatarsal; the other nine had a variability. Regarding the PLT, thirteen out of twenty had the normal insertion in the first metatarsal; the remaining seven had anatomical variants. CONCLUSIONS: In this study, we found a great variability in the insertional anatomy of PBT and PLT. CLINICAL RELEVANCE: It is important that orthopedic surgeons are aware of the great variability of PT anatomical insertion when performing foot and ankle surgery, in order to avoid possible complications, for instance a PLT injury during preparation of tarso-metatarsal arthrodeses.

Rotational Instability after Anterior Talofibular and Calcaneofibular Ligament Section: The Experimental Basis for the Ankle Pivot Test.

The clinical diagnosis of the anterior talofibular ligament (ATFL) rupture is based on the findings from the medical history and the anterior drawer test, a maneuver that allegedly pushes the talus and rearfoot anteriorly, although with great variability in its sensitivity. We consider that an ATFL rupture is best evaluated by a rotational vector (i.e., a pivot test) owing to the uncompromised medial ligaments that will block any pure anterior translation of the talus underneath the tibia. We idealized a constrained ankle cadaver model that only allows talar movements in the axial plane. Our hypothesis was that progressive sectioning of the lateral ankle ligaments in this model would cause a progressive and significant angular laxity in internal rotation. Our results showed 3.67 degrees ± 1.2 degrees of talus rotational laxity in the intact ankle, 9.6 degrees ± 3.2 degrees after ATFL sectioning, and 13.43 degrees ± 3.2 degrees after ATFL and calcaneofibular ligament sectioning, indicating almost threefold increase in internal talocrural rotation after single ATFL sectioning and an almost fourfold increase after double (ATFL and calcaneofibular ligament) sectioning. We consider this evidence of rotational ankle laxity to be a major step in defining the correct movement to diagnose an ATFL rupture and propose a new term to avoid further inconsistencies and variability, "the pivot test."

An anatomical study about the arthroscopic repair of the lateral ligament of the ankle.

BACKGROUND: The purpose of this anatomical study to was to determine the relationship of the structures involved in the arthroscopic repair of the anterior talofibular ligament. METHODS: Dissection of fifteen lower leg cadaveric specimens was made and distances in the anterior direction from the reference-point at the lateral malleolus origin of the anterior talofibular ligament were measured, to the talar insertion of the ligament, to the superficial peroneal nerve at 60° and 90° in relation to the lateral malleolus axis in the sagittal plane, and to the inferior extensor retinaculum. RESULTS: The mean±SD distance to superficial peroneal nerve from the reference-point was 25±6 (range 17-35) mm at 60°, and 32±9 (range 24-48) mm at 90° in relation to the lateral malleolus axis. The mean±SD distance to the inferior extensor retinaculum was 20±5 (range 14-29) mm. The mean±SD length of the anterior talofibular ligament was 21±4 (range 13-29) mm. CONCLUSIONS: The superficial peroneal nerve demonstrated the greatest variance in its anatomy. An accessory incision to include the inferior extensor retinaculum in the repair should not surpass the 22mm distance from the lateral malleolus in the anterior direction, due to the risk of damaging the nerve.