Spring Ligament Research Articles

Arthroscopic Repair of Acute Rupture of the Deltoid Ligament

Category:Ankle, Arthroscopy, TraumaIntroduction/Purpose:An ankle dislocation represents a high-energy traumatic injury that often occurs in traffic accidents or during jumping sports and usually it is associated with bi or trimalleolar fractures. Rupture of the deltoid ligament can occur alone or combined.There is currently extensive literature advocating LCL repair (assisted) by arthroscopy. However, the ruptures of the deltoid ligament are repaired by open technique: direct suture in acute cases and ligamentoplasty involving the Spring ligament in chronic cases. The possibility of repairing by arthroscopy allows an improvement in morbidity and complication rate. Undiagnosed and improperly treated medial collateral ligament (MCL) injuries can lead to disabling conditions.Methods:This study presents three cases of fracture-dislocation of the ankle with rupture of both collateral ligaments.Results:In addition to the usual osteosynthesis, it was also performed a ligament repair of the LCL with the arthroscopic Brostrom procedure. In the presence of medial instability, suture anchors were used to repairing the deltoid ligament and inferior extensor retinaculum via an arthroscopic technique.All patients presented a good functional recovery, two of them with AOFAS above of 83 at the end of the 6-month follow-up and with a complete return to daily living activities.Conclusion:Apart from having studied only three cases, the prospect of injury repaired by minimally invasive surgery in the acute phase seems advantageous in selected patients, avoiding evolution to a disabling chronic situation.

Early Outcomes of Pes Planus Reconstruction Using Either Hamstring Allograft or Synthetic Ligament

Category:Hindfoot, Midfoot/ForefootIntroduction/Purpose:Maintenance of the medial longitudinal arch is crucial to efficient kinematics in gait. It is supported by as complex interplay of osseous structures, ligaments, extrinsic tendons and plantar fascia.Two ligaments critical to stabilising the medial longitudinal arch are the Spring (Calcaneofibular) and Naviculocuneiform ligaments. The Spring Ligament serves as a sling within the “Acetabulum Pedis” to orientate the Talus relative to the Calcaneus and Navicular. The Naviculocuneiform ligament is an important plantar tension band and a separate entity to the Posterior Tibial Tendon (PTT) insertion. Attenuation of these ligaments leads to Pes Planus deformity and subsequent defunctioning of the PTT. This study evaluates the functional and radiological outcomes of Spring and Naviculocuneiform ligament reconstruction using Hamstring (Semitendinosis) Allograft and Synthetic ligament (Internal BraceTM, Arthrex).Methods:33 consecutive Pes Planus reconstructions were performed between 11/11/2013 and 06/03/2018. All patients were followed up prospectively with serial radiographs and functional scores including; MOXFQ, EQF5D and VAS. Minimum follow up was six months.At the midpoint during the study there was transition to using Synthetic Ligament instead of allograft. This was due to availability and ease of use.Surgical technique for both reconstructions included a proximal medial gastrocnemius recession and medialising calcaneal osteotomy. For allograft reconstructions, a pre-tensioned Semitendinosis allograft was fixed proximally to Talar neck using a tenodesis screw and passed plantar to PTT and through a bone tunnel in the medial cuneiform. Synthetic ligaments were inserted from the Sustentaculum Tali to the medial cuneiform in a hammock fashion. In both reconstructions tendinopathic PTTs were excised and a Flexor Digitorum Longus transfer used.Results:There were 17 synthetic ligament reconstructions (6 male, 11 female) and 16 allograft reconstructions (6 male, 10 female). Groups were matched pre-operatively for age, functional scores and radiological markers (T test P values >0.05).At six months significantly better improvements were observed in the synthetic ligament group compared to allograft group with regards to VAS, MOXFQ pain score, Meary’s line, 1st metatarsal Talus angle, Talonavicular uncoverage angle and Hindfoot alignment (T test P < 0.05).Statistical significance was maintained at 12 months with the synthetic ligament providing a significantly better reduction of Meary’s line 1st Metatarsal Talar angle, Talonavicular uncoverage and hindfoot alignment. 2 patients were revised to double fusions in the allograft group and 1 patient revised in the synthetic ligament group.Conclusion:Statistically significant improved functional scores and radiological appearance can be found up to 1 year following Synthetic ligament reconstruction of the Spring and Naviculocuneiform ligaments when compared to Hamstring allograft.

Subtle Dynamic Flatfoot Deformity: Is It More Than Stage I PTTD?

Adult acquired flat foot has long been considered synonymous with posterior tibial tendon dysfunction (PTTD), first described by Johnson and Strom in 1989. This is based on the authors’ clinical experience and a small case series described in 1994. However, there is little evidence that PTTD invariably leads to flat foot deformity. We propose a rethinking of stage I PTTD as subtle dynamic flatfoot, wherein adult acquired flat foot is driven largely by gastrocsoleus tightness and progressive hypermobility of the first ray. Clinical assessment should consist of careful evaluation of first ray stability as well as the spring ligament, tibiotalar range of motion, and impingement over the sinus tarsi. We present our preferred treatment strategy. Nonoperatively, patients are managed with a stretching program focused on the hamstrings and gastrocsoleus as well as the use of orthotics and night splint. Operative treatment consists of treatment of any areas of impingement and correcting the biomechanics of the foot and ankle with a Strayer, Cotton Osteotomy, and lateral column lengthening. Resection of the accessory facet of the talus is optional depending on preoperative symptoms.

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.

Morphology of Spring Ligament Fibrocartilage Complex Lesions.

The spring ligament fibrocartilage complex (SLFC) is an important static foot stabilizer comprising the superomedial ligament (SML) and the inferior ligament, with anatomical variations (third ligament). The aim of this study was to describe the patterns of the lesions found during SLFC surgery, to allow direct comparison between the results with various surgical techniques. Fourteen consecutive patients with SLFC lesions were analyzed during surgical treatment. The mean patient age was 37.3 years, and the mean time from injury was 6.9 months. Intraoperative assessments and anatomical descriptions of the lesions were collected. Three types of lesion were found. In 13 of 14 cases, only the superomedial ligament was involved: five superomedial ligament distentions and eight superomedial ligament ruptures. In one case, total SLFC (superomedial and inferior ligaments) rupture was observed. The first classification of SLFC lesions is presented, which is simple, consistent, and based on anatomical description.

Analysis of biomechanical stresses caused by hindfoot joint arthrodesis in the treatment of adult acquired flatfoot deformity: A finite element study

BackgroundTreatments of adult acquired flatfoot deformity in early stages (I–IIa–IIb) are focused on strengthening tendons, in isolation or combined with osteotomies, but in stage III, rigidity of foot deformity requires more restrictive procedures such as hindfoot joint arthrodesis. Few experimental studies have assessed the biomechanical effects of these treatments, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by both isolated hindfoot arthrodesis and triple arthrodesis on the main tissues that support the plantar arch. MethodsAn innovative finite element model was used to evaluate some flatfoot scenarios treated with isolated hindfoot arthrodesis and triple arthrodesis. Results and conclusionsWhen arthrodeses are done in situ, talonavicular seems a good option, possible superior to subtalar and at least equivalent to triple. Calcaneocuboid arthrodesis reduces significantly both fascia plantar and spring ligament stresses but concentrates higher stresses around the fused joint.

Nonanatomic versus anatomic techniques in spring ligament reconstruction: biomechanical assessment via a finite element model

BackgroundSeveral approaches to spring ligament reconstruction have been reported. However, a comparative study of nonanatomic and anatomic techniques with respect to biomechanical responses, such as kinematics and contact characteristics, has not been previously performed via a finite element analysis. The purpose of this study was to evaluate the biomechanical results of such spring ligament reconstructions via a finite element analysis.MethodsA three-dimensional finite element model of the foot was developed and validated, and four reconstruction methods were simulated. The talonavicular dorsiflexion and abduction, hindfoot valgus, and contact characteristics in the Chopart joints were quantified in each model.ResultsNonanatomic reconstructions corrected the talonavicular and hindfoot deformities to a greater extent than the anatomic reconstructions. The anatomic techniques also corrected the abduction and dorsiflexion deformities, although they presented insufficient power to correct for hindfoot valgus. None of the procedures restored the contact characteristics of the talonavicular and calcaneocuboid joints to those of a normal condition.ConclusionNonanatomic reconstruction of the spring ligament complex provided the greatest correction for midfoot and hindfoot misalignments in flatfoot. Severe deformities with large amounts of midfoot pronation and hindfoot valgus may be better treated with nonanatomic reconstruction methods. The spring ligament reconstruction method may mitigate the need for nonanatomic bony procedures associated with complications and allows for the preservation of the triple joint complex.

Deltoid-Spring Ligament Reconstruction in Adult Acquired Flatfoot Deformity With Medial Peritalar Instability.

A spring ligament tear is commonly present in advanced stages of adult acquired flatfoot deformity (AAFD). Previous anatomic studies have demonstrated that the superficial deltoid ligament blends with the superomedial spring ligament, forming the tibiocalcaneonavicular ligament (TCNL). Adding allograft TCNL reconstruction to osseous correction has been suggested to augment medial peritalar stability in advanced AAFD with large spring ligament tears. We aimed to investigate the clinical and radiographic outcomes of TCNL reconstruction for flexible AAFD with medial peritalar instability. Fourteen feet in 12 patients who underwent osseous and TCNL reconstructions for advanced AAFD (stage IIB with large spring ligament tears or stage IV) were recruited for the study. The mean postoperative follow-up was 24 (range, 12-33) months. Pre- and postoperative clinical outcomes were assessed by the Foot and Ankle Ability Measure (FAAM), SF-36, and Patient-Reported Outcomes Measurement Information System (PROMIS). Correction of forefoot abduction and the sagittal arch were measured from pre- and postoperative weightbearing radiographs. The FAAM Activities of Daily Living improved from 69.3 to 90.1 (P = .001). The SF-36 Physical Function (PF) and Pain subscales both improved significantly (39.4 to 87.8 and 44.6 to 93.1, respectively, P < .001 for each). The PROMIS PF improved from 38.2 to 46.8 (P = .002) and the PROMIS Pain Interference (PI) from 62.6 to 50.1 (P = .003). Radiographic measures showed an improved anterior-posterior (AP) talo-first metatarsal angle of 24.7 to 11.8 degrees (P < .001) and talonavicular coverage angle of 47.4 to 23.1 degrees (P < .01). An improved Meary's angle of 29.7 to 12.5 degrees (P < .001) and a calcaneal pitch angle of 11.7 to 16.9 degrees (P = .14) were noted in the lateral view. Considering the anatomic characteristics of the deltoid-spring ligament complex, TCNL reconstruction may play a significant role in maintaining peritalar stability when performed with osseous correction. Deltoid-spring ligament (TCNL) reconstruction is a viable surgical option for those with advanced stage AAFD with medial peritalar instability that leads to improved functional and radiographic outcomes. Level IV, retrospective case series.

Anatomic study of the medial side of the ankle base on the joint capsule: an alternative description of the deltoid and spring ligament

BackgroundAdult acquired flatfoot deformity (AAFD) is caused by impaired medial ligamentous structures and posterior tibialis tendon dysfunction (PTTD). Although degeneration and trauma could separately cause AAFD, how these factors interact in the pathomechanism of AAFD is unclear. The joint capsule in the medial ankle is considered an important structure, providing passive stability by limiting joint movement. Previous reports on the joint capsule suggest its involvement in pathological changes of the ankle, but because of the high priority placed on the ligaments, few reports address the ankle joint from the joint capsule standpoint. The current study aimed to anatomically examine the medial ankle joint, focusing on the deltoid and spring ligaments in perspective of the joint capsule.MethodsWe conducted a descriptive anatomical study of 19 embalmed cadavers (mean 82.7 years, range 58 to 99). We included 22 embalmed cadaveric ankles. We detached the joint capsule in 16 ankles from the anterior to posteromedial joint, analyzed the capsular attachments of the ankle and adjacent joints, and measured the widths of the bony attachments. We histologically analyzed the joint capsule using Masson’s trichrome staining in 6 ankles.ResultsThe capsule could be separated as a continuous sheet, including 3 different tissues. The anterior capsule was composed of fatty tissue. Between the medial malleolus and talus, the capsule was strongly connected and was composed of fibrous tissue, normally referred to as the deep deltoid ligament. The tibial attachment formed a steric groove, and the talar side of the attachment formed an elliptical depressed area. On the medial part of the subtalar and talonavicular joints, the capsule covered the joints as cartilaginous tissue, normally referred to as the superomedial ligament of the spring ligament. The outer side of the cartilaginous and fibrous tissue formed the sheath floor of the posterior tibialis tendon. Histological analysis revealed three different tissue types.ConclusionsThe capsules of the ankle, subtalar, and talonavicular joints could be detached as a continuous sheet. The deltoid and the superomedial ligament of the spring ligaments could be interpreted as a part of the continuous capsule, which had different histological features.Level of evidenceDescriptive Laboratory Study.

Medial foot and ankle instability

The deltoid or medial collateral ligament consisting of superficial and deep components together with the spring ligament is the primary stabilizer of the ankle joint. Injuries of these anatomical structures are more frequent than assumed but are nevertheless often overlooked. Inadequate treatment can lead to chronic pain, instability, hindfoot deformities and ankle arthritis. Patient history and clinical assessment can help to identify injuries of the deltoid ligament. Magnetic resonance imaging (MRI) is the diagnostic method of choice. Arthroscopy of the ankle joint can be avaluable tool in the assessment of the injury. Treatment should include accompanying injuries and deformities and can range from immobilization in acast to ligament repair up to ligament reconstruction using afree tendon graft.

Analysis of the main passive soft tissues associated with adult acquired flatfoot deformity development: A computational modeling approach

Adult acquired flatfoot deformity (AAFD) is a pathology with a wide range of treatment options. Physicians decide the best treatment based on their experience, so the process is entirely subjective. A better understanding of soft tissue stress and its contribution in supporting the plantar arch could help to guide the clinical decision. Traditional experimental trials cannot consistently evaluate the contribution of each tissue. Therefore, in this research a 3-Dimensional FE foot model was reconstructed from a normal patient in order to measure the stress of the passive stabilizers of the arch, and its variation in different scenarios related with intermediate stages of AAFD development. All bones, the plantar fascia (PF), cartilages, plantar ligaments and the spring ligament (SL) were included, respecting their anatomical distribution and biomechanical characteristics. An AAFD evaluation scenario was simulated. The relative contribution of each tissue was obtained comparing each result with a normal case. The results show that PF is the main tissue that prevents the arch elongation, while SL mainly reduces the foot pronation. Long and short plantar ligaments play a secondary role in this process. The stress increment on both PF and SL when one of two fails suggests that these tissues complement each other. These findings support the theory that regards the tibialis posterior tendon as a secondary actor in the arch maintenance, compared with the PF and the SL, because this tendon is overstretched by the hindfoot pronation around the talonavicular joint. This approach could help to improve the understanding of AAFD.

Anatomico-radiological Study of the Bifurcate Ligament of the Foot with Clinical Significance.

IntroductionLateral ankle sprain caused by forcible plantar flexion and inversion of the foot commonly damages the anterior talofibular ligament and other ligaments. Unfortunately, involvement of the bifurcate ligament (BL) is often overlooked when assessing such injuries in clinical practice and identification of this ligament on magnetic resonance (MR) scans can be challenging. Anatomically, the BL is a Y-shaped structure with two bands: the calcaneonavicular ligament (CNL) and calcaneocuboid ligament (CCL). There are few anatomical studies on the morphometric characteristics of the BL and even fewer biomechanical studies. Therefore, the objective of this anatomico-radiological study was to investigate the morphology of the BL using a multifaceted approach, and classify the fiber characteristics of the CNL and CCL.Materials and methodsWe measured the length and the width of 53 embalmed cadaveric feet. Meticulous dissection of each foot was performed to expose the BL. Measurements of the length, width, thickness, and shape of the CNL and CCL were taken using a digital caliper. We also documented the fiber orientation of each ligament, and used a goniometer to measure the bifurcation angle between the CNL and CCL via two methods. Confirmatory histologic analysis of the ligaments was performed and digital radiographs of the ligaments with attached radiopaque monofilament were taken. We also included an MR scan of the BL. Using descriptive and inferential statistics, we documented any significant relationships between the variables.Results Mean (range) age at death of cadavers was 76 (42-94) years. The CNL was found in all the feet and the CCL was not present in 9.4% of the feet. Mean (standard deviation) length of the CNL and CCL was 22.7 (4.12) mm and 10.9 (2.53) mm, respectively. Mean (standard deviation) thickness of the CNL and CCL was 3.23 (1.56) mm and 1.48 (0.71) mm, respectively. Related to ligament morphology, the CNL was most frequently cord shaped (67.92%) and the CCL was most frequently flat shaped (83.33%). The mean bifurcation angle measured 32.75o and 29.31o in methods 1 and 2, respectively. The correlation between the two measured angles was very strong (p < 0.001).DiscussionWe found that 90.6% of feet had both the CNL and CCL, 9.4% had the CNL and no CCL, and none (0%) had the CCL and no CNL. These frequencies are similar to a recent Japanese study. Our sample of donors were American and predominantly white. Whether the difference in frequencies between the studies is related to ethnicity is unknown and requires future investigation. Interestingly, on average the CNLs were twice as long and twice as thick as the CCLs. The CCLs tended to be wider distally and tapered compared to the CNLs.ConclusionsOur findings better classify the morphology and fiber orientation of the BL. Coupled with the radiographs and MR scan, our data may be of particular value to radiologists and surgeons. Our BL fiber orientation classification system and angle measurements can pave the way for future biomechanical studies to investigate any relationships between fiber type, angle, and strength of the constituent bands. More accurate descriptions of the BL should lead to improved diagnosis and treatment of ligamentous injuries of the foot.

Biomechanical stress analysis of the main soft tissues associated with the development of adult acquired flatfoot deformity

BackgroundAdult acquired flatfoot deformity (AAFD) is traditionally related to a tibialis posterior tendon deficiency. In the intermediate stages, treatments are commonly focused on reinforcing this tissue, but sometimes the deformation appears again over time, necessitating the use of more aggressive options. Tissue stress cannot be consistently evaluated through traditional experimental trials. Computational foot modeling extends knowledge of the disease and could help guide the clinical decisions. This study analyzes the biomechanical stress of the main tissues related to AAFD and their capacity to support the plantar arch. MethodsA FE foot model was reconstructed. All the bones, cartilages and tissues related to AAFD were included, respecting their biomechanical characteristics. The biomechanical tissue stress was quantified. The capacity of each soft tissue to support the plantar arch was measured, following clinical criteria. FindingsBiomechanical stress of the tibialis posterior tendon is considerably superior to both the plantar fascia and spring ligament stress. However, it cannot maintain the plantar arch by itself. Both the tibialis posterior tendon and spring ligament act in reducing the hindfoot pronation, while the plantar fascia is the main tissue that prevents arch elongation. The Achilles tendon action increases the plantar tissue stress. InterpretationThe tibialis posterior tendon stress increases when the spring ligament or the fascia plantar fails. These findings are consistent with the theory that regards the tibialis posterior tendon as a secondary actor because it cannot support the plantar arch and claudicates when the hindfoot has rotated around the talonavicular joint.

Spring ligament tear decreases static stability of the ankle joint

BackgroundSpring ligament tear is often found in advanced adult acquired flatfoot deformity and its reconstruction in conjunction with the deltoid ligament has been proposed to restore the tibiotalar and talonavicular joint stability. The aim of the present study is to determine the effect of spring ligament injury and subsequent reconstruction on static joint reactive force using a non-invasive method of measurement. MethodsTen fresh-frozen human cadaveric lower legs were disarticulated at the knee joint. Static joint reactive force of the tibiotalar and talonavicular joint were measured at baseline, after spring ligament injury, and after ligament reconstruction. Reconstruction consisted of a forked semitendinosis allograft with dual limbs to reconstruct the tibionavicular and tibiocalcaneal ligaments. FindingsThe mean baseline joint reactive force of the tibiotalar and talonavicular joints were 37.2 N + 8.1 N and 13.4 N + 4.2 N, respectively. The spring ligament injury model resulted in a significant 29% decrease in tibiotalar joint reactive force. Reconstruction of the tibionavicular limb resulted in a significant increase in tibiotalar and talonavicular joint reactive force compared to those seen in the injury state. Furthermore, the addition of the tibiocalcaneal limb significantly increased tibiotalar joint reactive force compared to those results obtained from the injury state and the tibionavicular limb alone. InterpretationThis is the first study to demonstrate diminished tibiotalar static joint reactive force in a spring ligament injury model with subsequent joint reactive force restoration using two-limbed reconstruction of the deltoid and spring ligament.Level of Evidence: Biomechanical Study.

An Anatomic Study of the Naviculocuneiform Ligament and Its Possible Role Maintaining the Medial Longitudinal Arch.

Weight-bearing radiographic analysis of pes planus deformities show, with varying degree of severity, a break in the Meary line. The break in the Meary line occurs not only at the talonavicular joint but also distal to the spring ligament and reported tibialis posterior insertion. Our aim in this study was to investigate the distal plantar ligaments of the medial longitudinal arch, to try to identify other areas where deformity correction could be affected. We examined 11 cadaveric lower limbs that had been preserved for dissection in a solution of formaldehyde. The lower limbs were carefully dissected to identify the plantar aspect of the medial longitudinal arch. In all specimens, the tibialis posterior tendon inserted into the plantar medial aspect of the navicular with separate slips to the intermediate and lateral cuneiform. The navicular cuneiform ligament extended from the navicular to medial cuneiform. This structure was statically inserted between the navicular and medial cuneiform, which would allow the pull of the tibialis posterior to act on the navicular and medial cuneiform in tandem. The average width of the naviculocuneiform ligament was 15.2 mm (range 12.4-18.0) compared to 9.5 mm (range 7.6-11.4) for the tibialis posterior tendon. The tibialis posterior tendon inserted into the navicular and continued onto the medial cuneiform to provide a static restraint between 2 bony insertions, thus supporting the distal aspect of the medial longitudinal arch. We are confident that it is a structure of importance in maintaining the distal aspect of the medial longitudinal arch and may therefore have significant clinical and surgical implications when treating the pes planus deformity.

Morphological features of the bifurcated ligament.

Damage to the bifurcate ligament is one of the most difficult injuries to diagnose from imaging techniques. A probable reason for this is that the morphological characteristics of this structure have yet to be sufficiently elucidated. We, therefore, endeavored to elucidate the morphological characteristics of the bifurcate ligament through a large-scale study involving numerous specimens. This study included 100feet from 52 formalin-fixed cadavers. The bifurcate ligament was classified into three types: presence of both calcaneonavicular ligament and calcaneocuboid ligament (Type I); absence of calcaneocuboid ligament (Type II); and absence of calcaneonavicular ligament (Type III). Morphological characteristics of the bifurcate ligament were determined by measuring fiber bundle length, width, and thickness at the center of each ligament. This classification resulted in 68 Type I feet (68%), 32 Type II feet (32%), and 0 Type III feet (0%). The calcaneonavicular ligament was 20.8 ± 2.9mm long, 4.9 ± 1.2mm wide, and 3.8 ± 1.1mm thick. The calcaneocuboid ligament was approximately 10.5 ± 2.7mm long, 4.7 ± 2.4mm wide, and 1.5 ± 0.6mm thick. The bifurcate ligament was located deep under the extensor hallucis brevis and extensor digitorum brevis muscles in all specimens. The calcaneal origin of the calcaneonavicular ligament was situated deep under the interosseous talocalcaneal ligament in all specimens. Two sides were identified in which the calcaneocuboid ligament was located deep under the dorsal calcaneocuboid ligament. Such variations and positional relationships were suggested to be factors complicating the diagnostic imaging of bifurcate ligament injuries. The present study results will likely form useful basic data for diagnostic imaging.

Normal and Injured Ankle Ligaments on Ultrasonography With Magnetic Resonance Imaging Correlation.

Ultrasonography (US) has been increasingly used in the evaluation of ankle ligamentous injuries given its advantages as a dynamic, efficient, noninvasive, and cost-effective imaging method. Understanding the anatomy of the ankle ligaments is critical for correct diagnosis and treatment. This pictorial essay describes and illustrates the US scanning technique and potential pitfalls in evaluating the ankle ligaments and also provides an overview of the US appearance of normal and injured ankle ligaments with magnetic resonance imaging correlation. Highlighted structures include the lateral complex, medial/deltoid complex, spring (calcaneonavicular) ligament complex, and syndesmosis.

Pilot Biomechanical Evaluation of Spring Ligament Augmentation with the Internal Brace in a Cadaveric Flatfoot Model

Category: Hindfoot Introduction/Purpose: Surgical reconstruction for flexible acquired flatfoot deformity from posterior tibial tendon dysfunction has been described and often includes a medial displacing calcaneal osteotomy (MDCO), Flexor digitorum longus (FDL) transfer, and possible spring ligament repair. However, the spring ligament is often attenuated leaving surgeons with few options for robust repair. Meanwhile, the Internal Brace (Arthrex, Naples, Florida) has been reported in a patient series as an excellent adjunct for spring ligament augmentation for the treatment of flatfoot correction with good clinical results. However, there are no biomechanical studies, which evaluate its safety or efficacy. The aim of this study is to perform a biomechanical comparison of spring ligament repair with Internal Brace augmentation to controls undergoing reconstruction of a flatfoot model. Methods: 4 paired (8 total), below the knee, cadaveric specimens, age 45.3 years (range; 30-60), without pre-existing foot deformity were utilized. Flatfoot model was achieved as described in the literature. Surgical reconstruction included MDCO (7.5 mm calcaneal plate), a spring ligament repair reefing (2-0 fiber wire suture), and an FDL transfer through a navicular bone tunnel with interference fixation via a biotenodesis screw (Arthrex, Naples, Florida). The experimental group received spring ligament augmentation with an internal brace as described by the manufacturer’s specifications. After potting, specimens were loaded statically to measure contact pressures and flatfoot correction. Achilles was tensioned to 350 N and cyclic loading was performed in a stepwise fashion after preconditioning. Loading occurred at 1 Hertz for 100 cycles, increasing at 100 N intervals to 1800 N. Tekscan contact pressures, radiography, and digitized measurements were repeated. Spring ligament repair site was evaluated and failures were recorded. Results: There was a statistically significant difference under cyclic loading of the internal brace augmented repair compared to standard suture repair alone (p=0.001). There were no failures of the internal brace device. Control spring ligament repair failed via suture cutout. There was 1 catastrophic specimen failure through the tibio-talar joint in each group (1000 N control; 1800 N experimental). The average change in talometatarsal angle was not statistically significant between the control (4.31±2.82) and the internal brace (4.06±2.74) (p=0.66) after loading. There was no difference in the change of peak intra-articular contact pressure at the talonavicular joint between flatfoot model and surgical correction when comparing the internal brace reconstruction (1478.8±306.6 pKa) and controls (1816.5 ±436.7pKa) (p=0.79). Conclusion: The use of the Internal Brace device to augment spring ligament reefing repair appears biomechanically safe and effective under cyclic specimen loading in a pilot, cadaveric flatfoot reconstruction model. Furthermore, it does not appear to alter intra-articular talonavicular joint contact pressures.

Tibiocalcaneonavicular Ligament Reconstruction in Simulated Flatfoot Deformity with Medial Ligament Insufficiency

Category: Hindfoot Introduction/Purpose: Spring ligament tear is often present in advanced stages of the AAFD. Anatomic studies have demonstrated that the superficial deltoid ligament blends with the superomedial spring ligament to provide medial tibiotalar and talonavicular stability. Reconstruction of combined deltoid-spring ligament, or the Tibiocalcaneonvaicular ligament (TCNL) was proposed to augment medial stability in advanced AAFD with large spring ligament tears. A tendon allograft is placed to cross three peritalar (tibiotalar, talonavicular and subtalar) joints to augment medial stability. We aimed to 1) investigate the kinematic effects of TCNL reconstruction in cadaveric flatfoot model with medial ligament insufficiency, and 2) compare TCNL reconstruction with anatomic spring and anatomic deltoid ligament reconstructions (Figure 1). We hypothesized that TCNL reconstruction is effective in restoring peritalar kinematics. Methods: Five fresh-frozen cadaveric foot specimens were employed. Advanced stage flatfoot model was created by sectioning the medial and inferior talonavicular interosseous ligament and extending the release 2 cm proximally along the superomedial spring ligament. Cyclic axial load of 1150 N under a hydraulic loading frame with constant 350 N Achilles tendon load were applied until &gt;15° talo-first metatarsal abduction was achieved. Bone tunnels were drilled for three reconstruction types, and the peroneus longus tendon was configured to reconstruct the 1) anatomic spring ligament, 2) anatomic deltoid ligament, and 3) TCNL. Reflective markers were mounted on the tibia, talus, navicula, calcaneus and first metatarsus. Each reconstruction type was loaded with 800 N ground reaction force, and kinematics of the peritalar joints were captured by 4-camera motion capture system. Forefoot abduction angle, Meary’s angle, and hindfoot valgus were calculated and compared to the severe flatfoot prior to reconstruction and to each using two-way ANOVA. Results: In creating the flatfoot deformity, both the tibiotalar and subtalar joints demonstrated an increase in valgus deformity by 5.6+3.7° and 6.1+5.3°, respectively, compared to the initial measurements. When comparing to the flatfoot deformity, the TCNL reconstruction achieved a significant improvement in percent correction of total hindfoot valgus (59.7+21.1%, p=0.017) and forefoot abduction angle (83.4+17.7%, p&lt;0.01). The spring ligament reconstruction also demonstrated a significant improvement in forefoot abduction correction compared to the flatfoot (52+10.6%, p&lt;0.05). No other reconstruction technique achieved a statistically significant improvement in percent correction compared to the flatfoot model in forefoot or hindfoot alignments. Additionally, no statistical differences were noted in the percent correction when comparing the three reconstructive techniques to each other. Conclusion: In advanced stage cadaveric flatfoot with spring ligament tear, we found increased valgus alignment at both the tibiotalar and subtalar joints. This kinematic changes reflects increased strain across the medial peritalar ligaments. The deltoid-spring ligament complex (TCNL) reconstruction demonstrated significantly improved alignment of hindfoot valgus and forefoot abduction compared to the severe flatfoot condition. This finding suggests that in addition to osseous correction and tendon transfer, the TCNL reconstruction may serve as an important component in augmenting medial stability in advanced AAFD with medial ligament insufficiency.

Peritalar Kinematic Changes Associated with Increased Spring Ligament Tear in Cadaveric Flatfoot Model

Category: Hindfoot Introduction/Purpose: Adult Acquired Flatfoot Deformity (AAFD) is a complex and progressive deformity characterized by abduction of the midfoot and valgus alignment of the hindfoot. Spring ligament tear is often present in advanced stages of the AAFD. Previous anatomic studies have demonstrated that the superficial deltoid ligament blends with the superomedial spring ligament to provide both medial tibiotalar and talonavicular stability aiding in coronal plane stability. Given that the spring ligament blends with the superficial deltoid ligament, we sought to investigate the kinematic effect of spring ligament tear in development of peritalar instability in cadaveric flatfoot model. We hypothesized that increased spring ligament tear size will result in increased talonavicular joint abduction (axial) and plantarflexion (sagittal), and increased valgus alignment of the tibiotalar and subtalar joints (coronal). Methods: Seven fresh-frozen cadaveric foot specimens were employed. Reflective markers were mounted on the tibia, talus, navicula, calcaneus and the first metatarsus. Kinematics of the peritalar joints were captured by multiple camera motion capture system. A flatfoot model was created by sectioning the medial and inferior talonavicular interosseous ligament, followed by cyclic axial load of 1150 N under a hydraulic loading frame with 350 N load applied to the Achilles tendon. The talo-first metatarsus (T- 1MT) abduction angle was calculated and cycles were applied until abduction of 5-10° (mild flatfoot) was achieved. Spring ligament sectioning was extended 1 cm proximally along the superomedial ligament followed by cyclic loading until 10-15° (moderate) of T- 1MT abduction was achieved. The spring ligament was sectioned for another 1 cm followed by cyclic loading until &gt;15° (severe) abduction was noted. The relative kinematic changes were compared among the initial, mild, moderate, and severe flatfoot model using two-way ANOVA. Results: The average T-1MT abduction angles in the mild, moderate, and severe flatfoot were 7.79°+/-2.27°, 11.47°+/-2.82°, and 15.46°+4.15°. Meary’s angle increased with progression of the flatfoot (mild 6.17°+/-2.92°, moderate 9.71°+/-3.4°, severe 12.46°+/-4.13°). Hindfoot valgus angle also increased. The mild, moderate, and severe flatfoot showed 2.4°+/-3.85°, 4.13°+/-3.9°, and 4.75°+/-3.79° of tibiotalar valgus angle. The subtalar joint exhibited 2.94°+/-3.41°, 5.52°+/-4.34°, and 6.97°+/-4.83° valgus angle in the mild, moderate, and severe models. The T-1MT abduction angle and Meary’s angle were significantly different in all flatfoot models compared to the initial condition (p&lt;0.001), and the severe vs. mild models (p&lt;0.01). Tibiotalar valgus was significantly increased in severe compared to the initial model (p=0.02). Subtalar valgus angle significantly increased in the moderate and severe models compared to the initial (p&lt;0.01, p&lt;0.001). Conclusion: Serial increment in spring ligament tear size in simulated flatfoot increased relative talus adduction and plantarflexion. It also resulted in gradual increment of valgus alignment of the tibiotalar and subtalar joints in coronal plane. This finding demonstrates that a large spring ligament tear in advanced stage AAFD leads to increased strain across the medial peritalar ligaments. In addition to osseous correction and tendon transfer, medial ligament augmentation, may be a critical component in surgical correction of AAFD with a large spring ligament tear.