Current Concepts With Revisional Bunion Surgery
The photo above at the right shows postoperative hallux varus due to overzealous capsulorrhaphy with a Lapidus bunionectomy. The hallux is adducted and the tibial sesamoid is peaking. Revision bunion surgery involved releasing the medial capsule and pinning the big toe in valgus for four to six weeks. The final image in the sequence demonstrates resolution of the hallux varus and the tibial sesamoid is realigned beneath the first metatarsal head.
One can correct a longstanding hallux varus and spare the big toe joint as long as the articular surface of the first metatarsophalangeal joint is in good condition and joint contractures are not drastic.
Evaluate both MPJ and hallux interphalangeal joint contractures individually. One can manage a hallux interphalangeal joint flexion contracture with a hallux interphalangeal joint fusion when the joint is rigid or severe. The focus is on salvaging the function of the big toe joint.
A common root cause of hallux varus is an overcorrected intermetatarsal angle. Previous removal of a fibular sesamoid exacerbates the situation. Reverse alignment procedures (such as reverse osteotomies or Lapidus) are the mainstays of the revision. However, it is important to consider the location of previous surgery and it may be beneficial to avoid reoperation on that particular spot depending on the blood supply and quality of the bone. Accordingly, surgeons may address a previous overcorrected distal metatarsal osteotomy with a proximal metatarsal osteotomy or midfoot fusion.
One patient had a hallux varus due to an overcorrected intermetatarsal angle combined with a fibular sesamoid release (see photo at left). The index bunion surgery occurred 20 years prior to revision. The first MPJ is intact overall but the metatarsal head is cystic, and the MPJ and hallux interphalangeal joint contractures are mild. A salvage revision bunion surgery involved a Lapidus midfoot fusion with a wedge cut to adduct the first metatarsal along with a first MPJ capsulorrhaphy and reattaching the extensor digitorum brevis to the lateral base of the hallux after passing it beneath the deep transverse intermetatarsal ligament. The clinical and radiographic results demonstrate correction of the hallux varus.
In regard to a non-salvageable deformity, severe longstanding contracture often requires a joint destructive procedure, again considering each patient individually. Implant arthroplasty is generally a poor choice for hallux varus revision due the muscular imbalances, and the fusion is often the better choice for these non-salvageable cases.
Another patient had longstanding severe hallux varus due to an overcorrected intermetatarsal angle combined with a fibular sesamoidectomy (see above right photo). The MPJ and hallux interphalangeal joint demonstrated rigid contractures. The revision surgery involved a MPJ and hallux interphalangeal joint fusion, extensor lengthening and Z-plasty of the skin. Some shortening of the hallux was necessary due to the longstanding contractures. The result was a straight big toe that fit in a shoe and a stable platform for weightbearing.