Posterior Medial Release for Clubfoot



Posterior Medial Release for Clubfoot


Todd A. Milbrandt

Vishwas R. Talwalkar



INTRODUCTION

It has been nearly 15 years since the Ponseti revolution overtook the treatment of clubfoot. His nonoperative technique of manipulation and casting followed by Achilles tenotomy is successful in greater than 90% of the cases leaving a functional and supple foot. While there is a significant relapse of the clubfoot with this treatment, an “a la carte” approach is now the norm to address recurrence that may include recasting, repeat Achilles tenotomy, tibialis anterior tendon transfer, cuboid osteotomy, or a combination of procedures. This tectonic shift in practice transformed the comprehensive posterior medial release from being one of the most frequently performed procedures in most pediatric orthopedic centers to one of the least.

Unfortunately, the children who are now candidates for this procedure frequently have undergone multiple attempts at correction that may distort anatomy or commonly have a diagnosis that makes the clubfoot recalcitrant (spina bifida, arthrogryposis, polio, spinal cord abnormalities, cerebral palsy, or muscular dystrophy). These issues combined with the relative rarity of these cases can increase the anxiety of the treating surgeon. This technique guide is our road map to make this complicated procedure manageable.




INDICATIONS



  • Failed Ponseti casting/manipulative techniques



    • Failed multiple rounds of casting and bracing


    • Diagnosis resistant to casting (myelomeningocele, arthrogryposis)


    • Skin breakdown


    • Family unable to obtain bracing


    • Foot resistant


    • Social situation not compatible with bracing


  • Foot position fixed in



    • Equinus


    • Varus


    • Adductus


    • Cavus


  • Child’s gait (Video 24-1, Pre-op):



    • Lateral weight bearing


    • Forefoot strike


    • No heel strike





CONTRAINDICATIONS



  • Unhealthy posterior and medial skin from either diagnosis or previous surgery


  • Tenuous vascular status


  • Previous posterior medial release (relative contraindication)



    • Consider correction through the bone and slow correction with external fixation


PREOPERATIVE PLANNING



  • Preoperative imaging



    • Radiography not helpful

    Consider pre-op video versus pedobarography for documentation of gait and plantar pressures



    • MRI or CT not indicated


  • Discuss pain control with anesthesia



    • Single-shot caudal block


    • Epidural catheter with infusion


    • Regional block with ultrasound injection


  • Positioning of patient



    • Bilateral feet



      • Prone position can achieve excellent visualization posteriorly


      • Medial-sided visualization not as good but still acceptable


    • Unilateral foot:



      • Lateral decubitus position that is not fixed using beanbag


      • Gently roll the patient more supine for medial side visualization


      • Gently roll the patient more prone for posterior visualization


      • Also called “lazy lateral” position


      • Prone position may also be useful for unilateral procedure


  • Tourniquet



    • Using nonsterile tourniquet protects the surgical field from any intrusion or drift if patient is large enough.


    • Sterile tourniquet can allow for complete removal so that vascular status can be completely evaluated, also better for small patient.


  • Imaging



    • Utilizing fluoroscopy to access location can assist in intraoperative understanding of anatomy.


    • Prefer mini-C-arm for the excellent visualization but less radiation dose.




SURGICAL PROCEDURE



  • Anesthesia induction with endotracheal tube not LMA



    • Allows for some patient manipulation during case


  • Surgical pause



    • Patient identification


    • Procedure confirmation


    • Correct limb confirmation


    • Antibiotic infusion


    • Designation of fire hazard and wound type


  • Positioning as discussed above



    • Prone for unilateral or bilateral cases


    • “Lazy lateral” for unilateral cases


  • Surgical preparation and draping



    • Bilateral cases: bilateral extremity drape


    • Unilateral cases: single extremity drape


    • Strip of adhesive sterile barrier around edges of drape


  • Mark incision with pen (Fig. 24-1)



    • Mark prior to inflation of tourniquet.


    • Cincinnati incision is a workhorse (allows extensive exposure medially and laterally).



      • Start laterally at a point 3 mm distal to lateral malleolus (can be extended if need for additional lateral procedure).


      • Curve posterior to a point over the Achilles tendon that is 2 cm superior to the top edge of the calcaneus.







        FIGURE 24-1 A. Turco incision. B. Cincinnati incision.



        • This needs to be centered at where you think the tibiotalar joint is located.


      • The marking then sweeps medially toward a point 5 mm distal to medial malleolus.


      • This continues distally past the navicular in line with the first ray.


    • Mark three to four vertical lines to mark for closure.



      • This is especially critical at the apex of the incision at the Achilles tendon.


  • Use Esmarch to exsanguinate the leg and inflate tourniquet.


  • Incision is made from the lateral malleolus to the medial malleolus area, extending it medially and laterally as necessary to achieve visualization.



    • Take caution when making incision over the Achilles tendon not to cut too deeply and inadvertently cut the tendon as it sits superficial.


    • A modified Turco incision may be useful in situations where a return to the OR for manipulation may not be feasible, such as in the developing world during mission work or if the child has significant medical comorbidities.


    • This incision can almost always be closed with the foot in a corrected position but makes the posterolateral portion of the release slightly more difficult to visualize.


  • Achilles tendon lengthening



    • The Achilles tendon is identified.


    • The paratenon is then dissected and the tendon is released 360 degrees.


    • One key is to use a mosquito clamp or small right angle anterior to the tendon and spread, freeing it from the soft tissues.


    • If previous percutaneous or open Achilles tendon lengthening has occurred, then the surgeon must work to free the tendon from the adhesions from the skin and deeper soft tissues.


    • Once exposed proximally to the myotendinous junction and distally to the insertion (an area of roughly 5 cm in length), then the lengthening can occur in a Z pattern.


    • The distal cut exits the tendon medially and the proximal cut exits laterally.


    • The Achilles tendon can then be sewn to the posterior skin at the calcaneus to add as a retractor of the skin and Achilles tendon itself for the remainder of the procedure.


  • Lateral dissection (Fig. 24-2):

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Jun 13, 2016 | Posted by in ORTHOPEDIC | Comments Off on Posterior Medial Release for Clubfoot

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