Essential Insights On Hallux Valgus

Author(s): 
By Richard O. Lundeen, DPM

Five Salient Points On Hallux Valgus Procedures

   After performing thousands of hallux valgus procedures of almost every type described in the literature, I would like to share what I have learned from my experience.    Closure of the intermetatarsal (IM) angle should not be the primary reason to select a particular surgical procedure. Experience and the literature support the fact that a basilar osteotomy of the first metatarsal will only reduce the IM angle 3 to 4 degrees. In addition, it provides relative elongation of the metatarsal and increases the proximal articular set angle (PASA), creating a “tighter” joint with dorsal jamming on weightbearing. This may necessitate additional distal procedures to reduce these complications. It is also well known that base osteotomies commonly elevate the metatarsal even after periods of nonweightbearing. Reducing the IM angle is still important but it should not be the primary goal in addressing hallux abducto valgus repair.    Decompression of the first metatarsophalangeal joint (MPJ) is necessary to allow IM angle reduction and prevent postoperative jamming of the joint and valgus subluxation of the hallux. In my experience of performing first MPJ arthroplasties with or without total joint replacement and fusion, resecting either component of the first MPJ (i.e., via Keller or Mayo procedures) reduces the retrograde forces from the hallux valgus deformity. This leads to decompression of the joint. As a result, the IM angle reduces usually as much or more than with a base wedge procedure. Only in rare cases would one see a very large and rigid IM angle that requires a metatarsal cuneiform fusion or base osteotomy.    Since the introduction of the Austin procedure, surgeons have noticed that modifications that shorten and plantarflex the first metatarsal, and allow reduction of the proximal articular set angle facilitate better MPJ motion. This is due to the resultant joint decompression and reduction of dorsal jamming from the head being dropped down and the realignment of the hallux with its metatarsal.    Correction of the proximal articular set angle (PASA) should be the primary goal that drives procedure selection. Adaptation of the first metatarsal head to the functional position of the hallux is what creates the PASA. Realigning the deviated metatarsal’s articular surface to its new functioning position should be the first priority when reducing the deformity. Then one can reduce the IM angle. Since PASA reduction provides relative lengthening of the metatarsal, one needs to perform some type of decompression procedure as well. This involves first metatarsal shortening and, preferably, concurrent plantarflexion of the metatarsal head to prevent its elevation.    Except in extreme cases, one can stabilize hypermobility of the first ray by joint decompression and reduction of the PASA and IM angle. The first ray (navicular, cuneiform and first metatarsal) cannot be stabilized in the transverse plane with a metatarsal-cuneiform fusion. Truly hypermobile first rays would present as a metatarsus primus elevatus on weightbearing radiographs with a navicular-cuneiform ptosis. This would require a navicular-cuneiform fusion of some type if the deformity is very flexible or rigid. If such a deformity exists for the first metatarsal-cuneiform joint, then it would need to be fused for stability. Transverse plane widening of the interspace between the first and second metatarsal bases (IM angle) will reduce without fusion.

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