Spring Ligament

27 Spring Ligament


Johnny T.C. Lau, Rupesh Puna, and Joyce Fu


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


27.1 Introduction


27.1.1 Pathology


• The spring ligament complex is an integral part of the foot.


• It provides static support to the medial longitudinal arch.


• Three bundles1:


image Superomedial calcaneonavicular ligament.


image Inferior calcaneonavicular ligament.


image 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


27.2 Indications


• 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).


27.2.1 Nonoperative Options


• Orthotics:


image Medial heel posting.


image Medial arch support.


27.2.2 Clinical Evaluation of Pathology


• Inspection in stance:


image Depression of medial longitudinal arch.


image Valgus hindfoot alignment.


image Pronation and abduction of the forefoot.


• Special examination maneuvers:


image Single-leg heel rise:


image Ability to perform with partial restoration of medial arch height indicates an intact PTT.


image Inability to perform suggests PTT dysfunction.


image Persistent forefoot abduction and valgus alignment of the hindfoot suggests spring ligament injury.3


27.2.3 Radiographic Evaluation


Weight-Bearing Radiographs of Bilateral Ankles and Feet

• Assessment of bony malalignment associated (i.e., pes planus deformity).


• Weight-bearing AP radiographs:


image Talar-first metatarsal angle.


image TN uncoverage.


image Talocalcaneal angle.


image Weight-bearing lateral radiographs.


image Medial cuneiform height.


image Meary’s angle (lateral talar-first metatarsal angle).


image Talocalcaneal angle.


Ultrasound

• Typical thickness of superomedial calcaneonavicular ligament is 4 mm (range 2.5–5.5 mm).


• Imaging of spring ligament insufficiency demonstrates


image Increased thickness (>5.5 mm).


image Loss of fibrillar echo pattern.


image 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


Magnetic Resonance Imaging

• Moderately sensitive, highly specific.6


• Appropriate for patients with more ill-defined symptoms or suspected bone or joint pathology.3
Injuries may appear widened on imaging, or can appear gapped from full-thickness rupture.6


• Evaluation of PTT should also be noted:


image Degeneration at hypovascular portion of tendon, distal to medial malleolus.7


27.2.4 Contraindications to Operative Management


• Fixed deformity of TN joint.


• Residual TN subluxation > 50%.


• Degenerative TN joint.


27.3 Goal of Procedure


• Restoration of TN alignment.8


• To avoid hindfoot fusion.4


• Maintenance of transverse tarsal motion.


• Reduction in pain and improvement of function.


27.4 Advantages of the Procedure


• 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.


27.5 Key Principle to Surgical Procedure


• 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.


27.6 Preoperative Preparation and Patient Positioning


27.6.1 Preoperative Radiology


• 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).


27.6.2 Reconstructive Graft Options


• Autograft (gracilis, semitendinosus, or peroneus longus4,10).


• Allograft (peroneus longus or semitendinosus).


• We prefer allograft to reduce donor site morbidity.


27.6.3 Positioning


• 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.


27.7 Operative Technique


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).


27.7.1 Approach


• 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.


27.7.2 Allograft Preparation


• 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).


27.7.3 Tunnel Preparation


• Tunnels are drilled in navicular, medial malleolus, and sustentaculum tali (based on anatomic footprints of the tibionavicular, tibiospring, inferior calcaneonavicular, and tibiocalcaneal ligaments).


27.7.4 Tunnel Location (Fig. 27.3)


In brief, these locations are the following:


image Navicular tunnel at medial edge of navicular tuberosity in a dorsal to plantar direction.


image Medial malleolus tunnel made vertically at anterior portion of intercolliculus aimed toward medial side of distal tibia.


Jul 19, 2019 | Posted by in SPORT MEDICINE | Comments Off on Spring Ligament
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