Minimizing The Risk Of Failed Hammertoe Surgery

Author(s): 
Johanna Richey, DPM, and Graham Hamilton, DPM, FACFAS

   It is important to consider the degree or severity of deformity. If the digit has been chronically dislocated, it will likely require not only some kind of tendon balancing and MPJ release but may also require a shortening osteotomy. Remember, the digit has been essentially shortened for a prolonged period of time while dislocated and will effectively lengthen following arthrodesis. Using a K-wire to reduce an unstable joint will only cause re-subluxation after pulling the pin. The K-wires do not correct deformity. They merely facilitate scarring of the soft tissues, primarily the MPJ capsule.

   Always assess the correction with the foot both unloaded and loaded. What is the toe going to look like when the patient bears weight?

   For revisional surgery, it is important to ask what went wrong with the index procedure. What deforming forces were not addressed? Ask if the surgeon under-addressed deformities or created any deformities.

   For example, functionally, there is no difference between arthroplasty and arthrodesis. Procedure selection is predicated on the desired outcome or effect of the procedure. Strength will improve following fusion because the vector of force of the long flexor will transmit through the MPJ with improved plantarflexion of the digit. However, one has also changed the tendon balance relationships of the digit and provided the long flexor with a mechanical advantage that over time creates a new deformity: mallet toe. Performing an FDL transfer will prevent this new deformity from occurring while also providing tendon balancing of the digit.

Case Study One: When A Patient Presents With Medial Deviation Of The Second Digit And An Overlapping Toe

A patient presented with significant medial deviation of the second digit with a rigid, overlapping second toe. She underwent several procedures in order to address the various deforming forces.

   First, the surgeon transected the extensor tendon at the level of the PIPJ and subsequently released the MPJ as the digit had been chronically dislocated dorsally with considerable soft tissue contractures about the MPJ. The surgeon completely released the medial joint capsule of the MPJ in order to address the significant medial deviation with transection of the medial collateral ligament.

   Surgeons subsequently performed an arthrodesis at the PIPJ to provide a stable rigid lever and prevent recurrence of a rigid deformity. They employed two pin fixation to provide stability against rotation with one of the pins crossing the MPJ to allow the digit to scar down in a more anatomic position. However, in order to prevent dorsal migration of the digit upon removal of the pin and simultaneously prevent compensatory mallet toe deformity, the surgeon transferred the FDL tendon to the dorsal base of the proximal phalanx.

   Subsequently, the surgeon reattached the extensor digitorum longus tendon (it had been previously transected at the level of the PIPJ and dissected out proximally) to the lateral aspect of the base of the proximal phalanx for lateral balancing.
The patient was completely satisfied three years postoperatively.

Case Study Two: When A Patient Presents With Predislocation Syndrome

A patient initially presented with symptoms of pain and dysfunction of the second toe that were consistent with predislocation syndrome. She had significant biomechanical pathologies that accounted for her deformity.

   First and most importantly, she had insufficiency of the first ray with metatarsus primus elevatus and a subsequent functional hallux limitus. This prevented appropriate propulsion off the first ray with transfer to the second MPJ. She also had a gastroc equinus manifested by significant extensor substitution during gait analysis and flexor stabilization secondary to her compensatory pronated foot. This contributed to her symmetric hammertoe deformity of digits two through four with adductovarus deformity of the fifth digit.

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