Lesser Metatarsalgia: Are Lesser Metatarsal Osteotomies Necessary?
Grebing and Coughlin successfully demonstrated the relationship of ankle position with the first ray mobility.8 They found that with the ankle joint plantarflexed and dorsiflexed, the first ray mobilities were larger and smaller, respectively, than when the testing occurred with the ankle in neutral position.
Furthermore, the Lapidus arthrodesis can stabilize the first ray and recreate a rigid lever arm through the medial column to absorb the ground reactive forces during weightbearing. The procedure is predictable in stabilizing the first ray in three planes with emphasis on the sagittal, frontal and intermetatarsal angles.9
These cases are associated with digital deformities as a result of retrograde lesser MPJ buckling, instability resulting in metatarsalgia, MPJ instability, lesser digit contracture and anterior muscle group weakness. One can correct these deformities in an attempt to balance the pathologic anatomic deformities.
Essential Surgical Pearls
The surgeon should employ a modified Hibbs procedure along with a Girdlestone-Taylor procedure. In doing so, one recruits the proximal extensor digitorum longus tendons and transfers them to the dorsal lateral foot to aid in ankle joint dorsiflexion while transferring the proximal extensor digitorum brevis tendons into the distal extensor digitorum longus tendon slips under physiologic tension. Essentially, these steps “weaken” the dorsiflexors of the toes.
Additionally, we perform a modified Girdlestone-Taylor procedure with the transfer of the flexor digitorum longus tendon to the extensor hood, release of the flexor digitorum brevis tendon insertions at the base of the middle phalanx (both medial and lateral slips), and a capsulotomy at the level of the proximal interphalangeal joint. We then use a Kirschner wire to temporarily stabilize the digit.
The modified Hibbs procedure is indicated for patients who exhibit isolated extensor substitution/recruitment or global extensor substitution/recruitment to the forefoot. Dorsal subluxations/dislocations at the MPJ are frequently linked with claw toes and hammertoes. These deformities typically result with the recruitment of a tight extensor digitorum longus (extensor substitution/recruitment) to support dorsiflexion against a tight posterior muscle group (equinus deformity).
Great care of the soft tissue is essential and fine double skin hooks are recommended for retraction in order to avoid soft tissue compromise.
Identify the extensor tendons (extensor digitorum longus and brevis) and separate only these tendons from the subcutaneous tissues. One should separate and track these longitudinally, and use caution to avoid neurovascular structures.
Isolate the second extensor digitorum longus tendon. Tenotomize and clamp the tendon using an Allis clamp as far proximal within the incision as possible. Tenotomize the extensor digitorum brevis tendons as far distal as possible (at the metatarsophalangeal joint level).
Perform a complete capsulotomy at the MPJ. This facilitates release of all contractures via sharp dissection and a McGlamry elevator, which allows for anatomic restoration of the metatarsophalangeal joint. In cases in which there is transverse plane pathology such as a crossover hammertoe, one can correct the transverse plane with a release of the necessary soft tissue.