Why The Lapidus Bunionectomy Is The Best Procedure For Severe Bunions
4. Concomitant treatment of lesser metatarsal overload. In many clinical situations, the severe bunion is associated with lesser metatarsal overload (metatarsalgia) through an inefficient medial column (first ray). Stabilizing and realigning the first ray through a Lapidus procedure provides a stable construct to the medial column and also improves the efficiency of the peroneus longus.16 It is important to inferiorly translate (or plantarflex) the first metatarsal as part of the surgery to restore the weightbearing presence of the first metatarsal head.
The Keller procedure is known to produce and exacerbate lesser metatarsal overload, and may be a poor procedure choice in patients who have metatarsalgia preoperatively. Implant arthroplasty carries a similar yet less infrequent postoperative lesser metatarsal overload risk, but one often must perform other procedures in conjunction to realign the first metatarsal.
5. Avoiding elevatus plastic deformation risk. Postoperative elevatus from early weightbearing is a real risk with base wedge osteotomies. Though this occurrence was more common when wire fixation was in use, the risk still remains with screw fixation. The plastic deformation of an osteotomy site is the result of premature weightbearing causing an intrinsic remodeling of the first metatarsal. With a Lapidus, however, elevation can occur but it may occur concomitantly with fixation failure and nonunion. The elevatus with a Lapidus is extrinsic to the metatarsal and the effect of the failed fusion elevating through the nonunion site.
6. Postoperative weightbearing. The ability for a patient to bear weight after a bunionectomy is often a deciding factor for procedure recommendation regardless of bunion size. Surgeons may make recommendations outside of specific intermetatarsal angle guidelines. Some doctors may even discourage bunion surgery altogether for the severe bunion because of a non-weightbearing protocol. Now that studies have emerged demonstrating that early weightbearing protocol healing rates are similar to that of non-weightbearing protocols, surgeons can consider the Lapidus as part of the potential surgeries when the post-op weightbearing is important.1-13
7. Lapidus failure is often less disruptive than failure from other bunionectomies. A failed bunionectomy is always a challenge for both the surgeon and the patient. With Lapidus, failures are typically in the realm of nonunion. I believe that that nonunion is not a failure but a known potential outcome in a certain percentage of people (but that is beyond the scope of this article). Nonetheless, a painful nonunion of Lapidus is typically focal to the first tarsometatarsal joint and one can rectify this with revision and grafting. Any recurrent angular deformity is through the first tarsometatarsal joint and also undergoes repair at the revision fusion site. A failed metatarsal bunionectomy often results in an intrinsic deformity, which requires metatarsal osteotomy or a revision Lapidus to correct.
Similarly, big toe joint fusions carry the risk of nonunion and malunion. In my experience, a nonunion of the first metatarsophalangeal joint (MPJ) is typically more symptomatic than a nonunion of the first tarsometatarsal joint. This seems to be due to the amount of load passing through the forefoot. Malunions of a first MPJ fusion can cause similar problems with that of a midfoot fusion and may require revision.