27 Spring Ligament Abstract The spring ligament complex is an important structure in the foot. In combination with the deltoid ligament, it provides major static stabilization of the medial longitudinal arch. The spring ligament is the primary restraint to talonavicular deformity, whereas the deltoid ligament provides the main restraint to valgus tilt and external rotation of the talus. There is a relative paucity of accepted methods of spring ligament reconstruction in current literature. This chapter will outline the evaluation of spring ligament pathology and detail our surgical reconstructive procedure of choice, which aims to simultaneously reconstruct both the spring ligament and deltoid given that both are often concurrently attenuated or pathologic, and we believe both should be addressed. Keywords: spring ligament, talocalcaneonavicular ligament, tibiospring ligament, medial longitudinal arch reconstruction, pes planus, planovalgus foot, posterior tibial tendon dysfunction • The spring ligament complex is an integral part of the foot. • It provides static support to the medial longitudinal arch. • Three bundles1: Superomedial calcaneonavicular ligament. Inferior calcaneonavicular ligament. Third ligament. • Pathology often noted in pes planus deformity. • Commonly associated with posterior tibial tendon (PTT) dysfunction but can also be independent of PTT dysfunction in the context of pes planus deformity.2,3 • Failure of conservative treatment. • More than 30 degrees of talonavicular (TN) uncoverage persisted on anteroposterior (AP) intraoperative fluoroscopic imaging. • Ten degrees of plantar TN sag persisted on lateral intraoperative fluoroscopic imaging.4 • Repair may be performed if notable tear or laxity found in the ligament intraoperatively (usually performed in combination with flatfoot correction). • Orthotics: Medial heel posting. Medial arch support. • Inspection in stance: Depression of medial longitudinal arch. Valgus hindfoot alignment. Pronation and abduction of the forefoot. • Special examination maneuvers: Single-leg heel rise: Ability to perform with partial restoration of medial arch height indicates an intact PTT. Inability to perform suggests PTT dysfunction. Persistent forefoot abduction and valgus alignment of the hindfoot suggests spring ligament injury.3 • Assessment of bony malalignment associated (i.e., pes planus deformity). • Weight-bearing AP radiographs: Talar-first metatarsal angle. TN uncoverage. Talocalcaneal angle. Weight-bearing lateral radiographs. Medial cuneiform height. Meary’s angle (lateral talar-first metatarsal angle). Talocalcaneal angle. • Typical thickness of superomedial calcaneonavicular ligament is 4 mm (range 2.5–5.5 mm). • Imaging of spring ligament insufficiency demonstrates Increased thickness (>5.5 mm). Loss of fibrillar echo pattern. Increased vascularity.3 • This may represent chronic repetitive injury or a healing acute rupture. • Dynamic ultrasound can also be used to evaluate PTT disorders. • If PTT ruptured, suspect spring ligament attrition.5 • Moderately sensitive, highly specific.6 • Appropriate for patients with more ill-defined symptoms or suspected bone or joint pathology.3 • Evaluation of PTT should also be noted: Degeneration at hypovascular portion of tendon, distal to medial malleolus.7 • Fixed deformity of TN joint. • Residual TN subluxation > 50%. • Degenerative TN joint. • Restoration of TN alignment.8 • To avoid hindfoot fusion.4 • Maintenance of transverse tarsal motion. • Reduction in pain and improvement of function. • Direct repair of insufficient medial spring ligament supporting the TN joint. • Addresses the medial and plantar band of the spring ligament. • Augmented reconstruction prevents delayed stretching out and failure of the repair. • Tibiospring, or tibiocalcaneonavicular (TCN) ligament is one of the most consistently found components of the deltoid.9 • Superficial deltoid blends with dorsal aspect of superomedial spring ligament to provide medial tibiotalar and TN stability. • It has the largest total attachment area and provides a significant portion of medial stability among other medial collateral and spring ligament complexes.9 • Our reconstructive procedure of choice aims to simultaneously reconstruct both the deltoid and spring ligaments. • We believe both components must be addressed to sufficiently correct alignment. • Bony realignment is imperative as an adjunct. • Weight-bearing films of the foot and ankle obtained. • Valgus stress films also completed to assess mortise and medial clear space (preoperative valgus tilt should be < 10 degrees). • MRI (magnetic resonance imaging) is obtained to assess the PTT and spring ligament. • Tunnels are drilled in navicular, medial malleolus, and sustentaculum tali (based on anatomic footprints of the tibionavicular, tibiospring, inferior calcaneonavicular, and tibiocalcaneal ligaments). • Autograft (gracilis, semitendinosus, or peroneus longus4,10). • Allograft (peroneus longus or semitendinosus). • We prefer allograft to reduce donor site morbidity. • Patient positioned supine with the operative extremity resting in external rotation. • Thigh tourniquet applied but not routinely inflated (senior surgeon’s preference). • Limb prepared with alcoholic chlorhexidine (70%/2%). • Preoperative antibiotic prophylaxis administered. Our technique is essentially the same as that published by Grunfeld et al.11 Our preference is to simultaneously reconstruct both the deltoid and spring ligament. Bony corrective procedures are initially performed (medial translational calcaneal osteotomy and/or first ray plantar flexion osteotomy and/or plantar flexion osteotomy of the first metatarsal). • Universal medial longitudinal incision. • PTT sheath is incised and the diseased portion of PTT is excised. • Flexor digitorum longus (FDL) is harvested at master knot of Henry. • One to five toes and ankle are maximally plantarflexed to maximize the length of FDL tendon harvested. • FDL is tenodesed to flexor hallucis longus (FHL) prior to sectioning. • Medial ligament complex is inspected and tears of native spring ligament are repaired and imbricated if possible. • Allograft peroneus longus is our preferred graft. • Length of graft required is usually 25 cm (diameter ~ 6 mm). • Allograft is folded in half to create two limbs (Fig 27.1). • Folded portion of 2 cm is trimmed to allow easy passage through 7-mm sizer (Fig 27.2). • No. 2 Ethibond is placed in folded portion, and also in distal 4 cm of each limb (Fig 27.2). • Tunnels are drilled in navicular, medial malleolus, and sustentaculum tali (based on anatomic footprints of the tibionavicular, tibiospring, inferior calcaneonavicular, and tibiocalcaneal ligaments). In brief, these locations are the following: Navicular tunnel at medial edge of navicular tuberosity in a dorsal to plantar direction. Medial malleolus tunnel made vertically at anterior portion of intercolliculus aimed toward medial side of distal tibia.
27.1 Introduction
27.1.1 Pathology
27.2 Indications
27.2.1 Nonoperative Options
27.2.2 Clinical Evaluation of Pathology
27.2.3 Radiographic Evaluation
Weight-Bearing Radiographs of Bilateral Ankles and Feet
Ultrasound
Magnetic Resonance Imaging
Injuries may appear widened on imaging, or can appear gapped from full-thickness rupture.6
27.2.4 Contraindications to Operative Management
27.3 Goal of Procedure
27.4 Advantages of the Procedure
27.5 Key Principle to Surgical Procedure
27.6 Preoperative Preparation and Patient Positioning
27.6.1 Preoperative Radiology
27.6.2 Reconstructive Graft Options
27.6.3 Positioning
27.7 Operative Technique
27.7.1 Approach
27.7.2 Allograft Preparation
27.7.3 Tunnel Preparation
27.7.4 Tunnel Location (Fig. 27.3)