Spring Ligament Injury

Spring ligament complex injuries or calcaneonavicular ligament injuries refer to stretching sprains, tears, or ruptures of the plantar calcaneonavicular ligament complex and can affect one or more of the three portions. Since spring ligament repair is often combined with a flatfoot reconstruction, recovery involves typically six weeks of non-weightbearing then a walking boot. Physical therapy is required for optimal results, and recovery can take up to 9-12 months.

A spring ligament injury refers to stretching, partial or complete tear of the spring ligament complex that acts as a static stabilizer of the medial longitudinal arch. It can affect one or more of the following ligamentous portions 1–3: superomedial calcaneonavicular ligament (clinically most relevant). Spring ligament complex injuries are most commonly associated with posterior tibial tendon dysfunction and are rare in isolation. Middle-aged women are most commonly affected.

The plantar calcaneonavicular ligament also referred to as the spring ligament is a thick wide band of cartilaginous connective tissue that supports the medial longitudinal arch of the foot, failure in the spring ligament leads to flat foot deformity. The spring ligament despite its name does not possess spring-like properties as it is highly collagenous.

  • General
    • Overall rare diseases are poorly described in the literature
    • Can be acute and seen in athletes
    • The chronic, degenerative form is often seen along with Posterior Tibial Tendon Dysfunction

Causes

  • Chronic
    • Most of the literature discusses chronic degenerative changes
    • Associated with Posterior Tibial Tendon Dysfunction
  • Acute
    • Associated with running and jumping sports
    • Often results from an abduction or eversion type mechanism during sports
    • An awkward landing from a fall can also injure the spring ligament
    • Many athletes have an unclear mechanism of injury and describe a sprain injury.

Associated Conditions

  • Posterior Tibial Tendon Dysfunction
  • Deltoid Ligament Injury
  • Chopart Complex Injury

Pathoanatomy

  • Spring Ligament Complex
    • Originates on the calcaneus, inserts into the navicular
    • Consists of
      • Superomedial calcaneonavicular ligament (SmCNL)
      • Medioplantar oblique calcaneonavicular ligament (MpoCNL)
      • Inferoplantar longitudinal calcaneonavicular ligament (IplCNL)
    • Function: stabilize the talonavicular joint, longitudinal arch of the foot
      • In conjunction with posterior tibial tendon
  • Sports (case reports only)
    • Track and Field
      • Pole Vaulting[3]
      • Jumper[4]
    • Soccer
    • Cricket
    • Tennis[5]
    • Hiking[6]

Differential Diagnosis

  • Fractures & Osseous Disease
    • Traumatic/ Acute
      • Talus Fracture
      • Calcaneus Fracture
      • Traumatic Navicular Fracture
      • Cuboid Fracture
      • Cuneiform Fracture
      • Metatarsal Fracture
        • Fifth Metatarsal Fracture
      • Toe Fracture
      • Hallux Sesamoid Fracture
    • Stress Fractures
      • Navicular Stress Fracture
      • Metatarsal Stress Fracture
    • Other Osseous
      • Tarsal Coalition
      • Accessory Navicular Syndrome
  • Dislocations & Subluxations
    • Toe Dislocation
    • Lisfranc Injury
    • Chopart Complex Injury
    • Cuboid Syndrome
  • Muscle and Tendon Injuries
    • Posterior Tibial Tendon Dysfunction
    • Peroneal Tendonitis
    • Tibialis Anterior Tendinopathy
    • Flexor Hallucis Longus Tendinopathy
  • Ligament Injuries
    • Plantar Fasciopathy (Plantar Fasciitis)
    • Turf Toe
    • Plantar Plate Tear
    • Spring Ligament Injury
  • Neuropathies
    • Mortons Neuroma
    • Tarsal Tunnel Syndrome
    • Joggers Foot (Medial Plantar Nerve)
    • Baxters Neuropathy (Lateral Plantar Nerve)
  • Arthropathies
    • Hallux Rigidus (1st MTPJ OA)
    • Gout
  • Toenail
    • Subungual Hematoma
    • Subungual Exostosis
    • Nail Bed Laceration
    • Onychocryptosis (Ingrown Toenail)
    • Onychodystrophy
    • Paronychia
    • Onychomycosis
  • Pediatrics
    • Fifth Metatarsal Apophysitis (Iselin’s Disease)
    • Calcaneal Apophysitis (Sever’s Disease)
    • Freibergs Disease (Avascular Necrosis of the Metatarsal Head)

Diagnosis

  • History
    • Inability to bear weight immediately following injury may correlate to the degree or severity of the injury
    • Pain along arch extending towards medial malleolus and retromalleolus
    • Some patients may have lateral pain, an impingement in the sinus tarsi region[7]
    • Patients may report early vague activity-related medial ankle and foot pain, difficulties walking on uneven ground, and/or balance problems
  • Physical Exam: Physical Exam Foot
    • Medial arch swelling, tenderness is typically present
    • The tenderness between the sustentaculum tali and the navicular
  • Special Tests
    • Too Many Toes Sign: Too many toes seen on the affected limb from posterior evaluation
    • Single Limb Heel Rise: The patient performs a single-limb heel raise

Radiographs

  • Standard Radiographs Foot
    • Useful to exclude evidence of deltoid injury
  • Potential findings
    • Abduction and uncoverage of the talonavicular joint
    • Loss of the medial longitudinal arch
    • Dorsal subluxation of the navicular
  • Meary’s Angle[8]
    • Lateral talo-1st metatarsal angle is used to assess flatfoot deformity
    • Normal: lateral talo-1st metatarsal angle less than 4°
    • Abnormal: large angle often indicates flatfoot deformity

MRI

  • Gold standard diagnostic imaging modality
  • Useful to evaluate
    • Spring Ligament
    • Posterior Tibial Tendon
  • Findings
    • Edema of navicular, talar head
  • Findings for superomedial calcaneonavicular ligament (SmCNL)[9]
    • Best seen on axial and coronal cuts
    • Abnormally high signal intensity on T2-weighted or proton density (PD) images
    • Thickening (>5–6 mm), thinning (<2 mm), waviness, and discontinuity
  • ICN Bundle
    • Best seen on axial and coronal images
    • Intermediate signal intensity on T1, low intensity on T2 images
  • MPO bundle
    • Harder to visualize
    • Has a striated appearance on the axial and coronal images
  • Diagnostic accuracy[9]
    • Sensitivity: 55%
    • Specificity: 100%

Ultrasound

  • Utility
    • Visualize the superior medial bundle
    • Can indicate disruption or thickening of the ligament fibers
    • Allows visualization of the distal aspect of the posterior tibialis tendon

Classification

Gazdag and Cracchiolo Classification

  • General[10]
    • Describes spring ligament disease in the setting of posterior tibial tendon dysfunction
    • Currently, no classification system exists for isolated spring ligament injury
  • Grade 1
    • Longitudinal tear within the midsubstance
    • OR partial tears at the ligament’s insertion on the sustentaculum tali or the navicular
    • OR a single longitudinal tear or several small tears at the ligament insertion.
    • No apparent ligamentous laxity
  • Grade 2
    • Loose ligament that appears stretched, with or without visible tears
  • Grade 3
    • Complete rupture of the ligament.

Management

Nonoperative

  • Indications
    • First-line treatment for the vast majority of cases
    • Partial injury without arch collapse or pes planus
  • RICE Therapy initially
  • Immobilization/ Protection
    • Individuals should be in Short Walking Boot with non-weight-bearing status (NWB) until a definitive diagnosis is made[11]
    • Once a diagnosis is confirmed, NWB status should be maintained for 6 weeks
    • Subsequently, a patient can be weened out of boot over 3-4 weeks
    • As the patient is weaned, a custom Orthotic Arch Support should be prescribed
  • Weight-bearing status
    • Most patients should be NWB for about 6 weeks
    • Following this, they can initiate weightbearing progression along with physical therapy
  • Physical Therapy

Operative

  • Indications
    • Complete tear of the ligament complex
    • Resultant foot deformity
    • Consider in all young or competitive athletes
  • Technique
    • Spring Ligament Reconstruction
    • Spring Ligament Repair
    • Posterior Tibial Tendon as indicated