Essential Insights On The Medial Slide Calcaneal Osteotomy
Both pediatric and adult-acquired flatfoot deformities, particularly posterior tibial tendon dysfunction (PTTD) stage II, remain difficult to treat and there is much controversy in regard to the optimal form of treatment. Patients usually present with increased pain and swelling along the medial aspect of the ankle or rearfoot. The foot generally maintains an abducted forefoot position and a decrease in the height of the medial longitudinal arch. Sometimes patients can perform a double heel raise but cannot perform a single heel raise. This signifies posterior tibial tendon pathology.
The success of conservative treatment options such as immobilization, rest, ice, nonsteroidal anti-inflammatory drugs (NSAIDs), ankle foot orthoses or physical therapy depends on the stage of the deformity, duration and severity of symptoms. After one has exhausted all conservative measures, treating physicians may consider surgical options, taking into account the severity of the deformity, flexibility and planal dominance as well as the patient’s age and functional demands.
The surgical correction of stage II PTTD often requires soft tissue augmentation of the posterior tibial tendon along with structural or bony reconstruction. Koutsogiannis first suggested sliding the calcaneus medially as a treatment for flexible pes planus.1 Surgeons may employ the medial slide calcaneal osteotomy to treat flatfoot deformities in both the adult and pediatric patient but it is rarely in use as an isolated procedure. Surgeons commonly perform the medial slide calcaneal osteotomy in conjunction with a flexor digitorum longus tendon transfer, lateral column lengthening or a medial cuneiform osteotomy or arthrodesis.
The surgeon also needs to address any equinus deformity associated with the pathology. When it comes to lengthening the gastrocnemius-soleus complex, there are many surgical techniques one can use. We prefer a percutaneous Achilles tendon hemi-sectioning technique or endoscopic gastrocnemius recession when appropriate. The medial slide calcaneal osteotomy alters the pull of the gastrocnemius-soleus muscle group slightly medial to the axis of the subtalar joint. This effectively places the Achilles tendon medially and increases the varus pull on the hindfoot while correcting the rearfoot valgus alignment. Transfer of the flexor digitorum longus tendon aids in restoring the inversion function of the posterior tibial tendon.2
Conventional fixation of the osteotomy occurs with a large headed screw. However, this technique has been associated with high rates of complications due to posterior irritation from the screw head, subsequently leading to its removal.3 Fixation methods for osteotomies have advanced throughout the years and include the use of headless screws as well as non-locking and locking plates. Some have advocated fixed angle, locking step-off plates for the medial slide calcaneal osteotomy. These plates have an incorporated translational distance with a step-off to allow for the desired medial shift (6 to 10 mm) of the calcaneal tuberosity.
A Step-By-Step Guide To Surgical Technique
Ensure that the patient is in a supine position on the operating table. Utilize a thigh tourniquet unless it is contraindicated. Start the incision at the superior lateral aspect of the calcaneal tuberosity and extend it distally and inferiorly at a 45 degree angle to the weightbearing surface, parallel to the peroneal tendons. Take care to avoid injury to the sural nerve by utilizing blunt dissection until you locate and retract the nerve. Then perform sharp dissection to the periosteal layer along the lateral aspect of the calcaneus.