Essential Insights On Hallux Valgus

By Richard O. Lundeen, DPM

   Back when I left the didactic world of podiatry school and entered my residency, I was ready for a transition that would blend the books with practice. Of course, the first two surgeries I performed did not fit the mold. The first one was a cartilage articulation preservation procedure (CAPP) and the other was a Keller procedure.    The CAPP procedure was familiar to me only in books and the Keller seemed “outdated.” To my surprise, both surgeries turned out well and gave me an appreciation that diverse types of procedures can have a good outcome when they are performed well and on the proper patients.    Granted, there were old standards like the first metatarsophalangeal fusion and Lapidus procedures but during my residency, new surgical procedures like the Austin and Scarf were coming down the pike for hallux valgus. There were also innovative new procedures (such as the Swanson total joint arthroplasty and Juvara basal osteotomy) that enthusiastic residents like myself quickly adapted.    During the first part of my residency, base wedge osteotomies were the norm. We would commonly do them bilaterally, with or without a pin for fixation, and use circlage wire across the osteotomy. Patients usually walked on these osteotomies the day of surgery. Today, a base wedge would not be treated in this manner. The latter days of my training revolved around the Austin procedure. At first, we would not fixate the capital fragment but after a couple of metatarsal heads dislocated, they were all fixated. The Austin was certainly easier to perform than the base wedges and healed a lot faster with fewer complications. Patients were up and in shoes faster.

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.    Functional hallux limitus with or without metatarsus primus elevatus is a component of almost every case of hallux abducto valgus. When evaluating a bunion deformity, one should load the first ray and put the first MPJ through a range of motion. Upon dorsiflexion, the joint will invariably jam, either preventing further dorsal migration (look for a hallux extensus) or causing further dorsiflexion through a valgus rotation of the hallux. In both cases, one needs to decompress and plantarflex the first metatarsal joint. If there is a remaining valgus rotation with the joint loaded, then one would likely need to excise the fibular sesamoid.

Why I Prefer The Modified Weil Osteotomy

   I could live with any or all combined procedures that address these five points. The best of all worlds would be one that accomplishes most of these goals easily with the least risk of complication and the quickest recovery for the patient.    I have accomplished this via a modified Weil osteotomy through the first metatarsal head in an oblique fashion from dorsal-distal to plantar-proximal.    Before the osteotomy, make a medial, curvilinear capsulotomy, allowing exposure of the metatarsal head for resection of the medial eminence. Following the osteotomy, reduce the head of any PASA and then translocate the head laterally to reduce the IM angle. Some shortening has to occur here for joint decompression. This osteotomy allows plantarflexion with concurrent shortening for decompression. However, one should only allow enough shortening to preserve a normal amount of dorsiflexion without jamming the joint. Excessive shortening can cause the hallux to remain dorsiflexed, preventing adequate toe purchase on the ground due to concurrent plantarflexion of the head.    In regard to fixation of the osteotomy, one would utilize two 0.62 inch threaded Kirschner wires in the metatarsal head that are cut flush to the bone. Close the capsule with large oblique sutures of 2-0 absorbable material with the hallux held in the corrected position. Allow the patient to ambulate in a surgical shoe and emphasize weekly dressing changes for 18 to 21 days. At that time, one can remove the sutures and place the foot in a mild compression wrap (like a Darco forefoot sleeve), and allow the patient to begin wearing an oversized soft shoe. Dr. Lundeen is Residency Director of the Winona Hospital Podiatric Residency Program in Indianapolis. Dr. Burks is a Fellow of the American College of Foot and Ankle Surgeons and is board certified in foot and ankle surgery. Dr. Burks practices in Little Rock, Ark.

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