Deltoid Ligament Injuries  

Introduction 

Isolated injuries are rare.

Acute

  • associated with ankle fracture, syndesmotic or lateral ligament injury 
  • limited evidence for acute repair 
  • anatomic reduction of fractures, syndesmotic stability and mortise congruency are the key  

Chronic

  • associated with spring ligament injury 
  • tibialis posterior insufficiency 
  • lateral ligament instability 

Anatomy

  • Large, fan-shaped (delta) 
  • Broad insertion to talus, calcaneus, navicular 
  • Forms a functional unit along with the spring ligament and tibialis posterior tendon 
  • Described as having superficial & deep components 

Superficial

  • Tibionavicular (TNL)  
  • Tibiospring (TSL) 
  • Tibiocalcaneal (TCL)  
  • Plantar calcaneonavicular = spring lig (SL) 

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Deep

  • Anterior tibiotalar (aTTL)   
  • Posterior tibiotalar (pTTL) 

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Figures from: Dabash S et al. Adding deltoid ligament repair in ankle fracture treatment: is it necessary? A systematic review.  Foot Ankle Surg 2019;25:714-720

Function 

  • Superficial – primary restraint to hindfoot eversion 
  • Deep – primary restraint to talar external rotation 
  • Deep deltoid is main restraint to a valgus force 
  • Restricts anterior and lateral translation of the talus 

Ankle fracture

  • Supination External Rotation (SER) stage IV = ‘bimalleolar-equivalent’  
  • Less common in PER or Pronation Abduction  

Diagnosis of deltoid injury 

  • Swelling; ecchymosis; tenderness – poor correlation with injury  
  • Stress radiography – external rotation stress test; gravity stress; WB views 
  • MRI – specific but high variability regarding degree of associated medial instability  

Indication for acute deltoid repair 

Controversial 

? repair restores medial check-rein 

Recommendations vary from no repair through to every ‘bimalleolar-equivalent’, whilst others consider the possibility of repair in selected circumstances: 

  • High-level athletes 
  • If medial gutter clearance is required to allow reduction of the mortise 
  • Persistent medial-sided instability after ORIF on stress-testing under II (ext rot + talar tilt) 

Techniques of acute repair 

  • Avulsion from MM (most common): suture anchor(s) into MM & capsule/deep deltoid/superficial deltoid imbricated as ‘pants-over-vest’ repair 
  • Distal talar rupture – techniques described of inserting anchor(s) into medial talus 

Outcomes of acute repair 

  • Most studies show good results without deltoid repair as long as the key principles of anatomic fracture reduction, syndesmotic stability, and mortise congruency are achieved 
  • Recent study shown good results in high-level NFL athletes 
  • One study suggests that deltoid repair may negate the need for syndesmosis stabilization  
  • Recent systematic review concludes that: 
  • current literature does not provide enough clear evidence to guide operative intervention for the deltoid in acute ankle fracture 
  • Injuries with an associated high fibular fracture or syndesmosis injury may possibly benefit from addressing the deltoid 

Chronic deltoid insufficiency 

Challenging problem both diagnostically and surgically 

Diagnosis 

Clinical symptoms 

  • Giving way 
  • Antero-medial ankle pain 
  • Recurrent injury 

Clinical examination 

  • Valgus malalignment (asymmetrical planus and pronation) on WB 
  • Valgus corrects on tiptoe (tib post activation)  
  • Medial arch preserved 

*awaiting image upload*

Figures from: Hintermann B et al. Medial ankle instability: an exploratory prospective study of 52 cases. Am J Sports med 2004;32:185-190

Investigations

X-ray 

  • Stress test – valgus tilt; antero-medial draw 

MRI 

  • Visualise deltoid 
  • Assess spring ligament and PTT 

Arthroscopic confirmation 

  • Positive ‘drive-through’ of 5mm instrument in the medial gutter 
  • Denuded MM 
  • Attenuation or absence of ligament 

Surgery 

If conservative treatments have failed then surgical intervention may be necessary 

May need to be combined with additional procedures:

  • multiplanar instability 
  • flatfoot reconstruction 
  • re-alignment osteotomy 
  • Because of the reliance of the repair/reconstruction on additional procedures, plus the relatively small number of cases, it is difficult to compare one technique with another 

Deltoid repair 

If adequate tissue is present the deltoid can be elevated from the medial malleolus.  

It can be reattached after tensioning or shortening using suture anchors. 

The repair can be augmented with allograft or fibre-tape if necessary. 

Deltoid Reconstruction 

Lack of adequate tissue to allow for repair, and/or a variety of pathologies, has led to a number of different procedures of reconstruction being described.   

Most of the techniques involve the use of allograft as a complex tenodesis and have been described for deltoid/spring ligament reconstruction in significant flatfoot deformity (often stage IV PTT deformity). Autografts described include peroneus longus, plantaris, semitendinosus. 

 

References 

Dabash S et al. Adding deltoid ligament repair in ankle fracture treatment: is it necessary? A systematic review.  Foot Ankle Surg 2019;25:714-720. 

Hintermann B et al. Medial ankle instability: an exploratory prospective study of 52 cases. Am J Sports Med 2004;32:185-190. 

Lee S et al. Deltoid ligament rupture in ankle fracture: diagnosis and management. JAAOS 2019;27:648-658. 

Savage-Elliott I et al. The deltoid ligament: an in-depth review of anatomy, function & treatment strategies.  Knee Surg Sports Traumatol Arthrosc; 2013;21:1316-1327.