Why The Lapidus Bunionectomy Is The Best Procedure For Severe Bunions
A failed Keller or implant procedure involves a revision fusion of the first MPJ with bone block grafting, a procedure that involves a prolonged period of convalescence and non-weightbearing. These reconstructions are challenging for both patient and surgeon.
8. Improving rearfoot alignment. Realigning and stabilizing the first ray has a realigning effect on the rearfoot as well. This is an advantage of the Lapidus. A retrospective radiographic study by Avino and collagues demonstrated radiographic improvement of the talo-first metatarsal angle.17
Key Preoperative Considerations
When considering the Lapidus bunionectomy for severe bunions, it is important to carefully evaluate the first MPJ for arthritis and the second MPJ for subluxation with overload symptoms. When these clinical conditions occur in conjunction with the severe bunion, other procedures may be needed in addition to the Lapidus to balance the foot. With end-stage problems, however, other bunionectomies may be better indicated.
Arthrosis of the first MPJ with severe bunions is often due to malalignment, wear and tear. Of course, several degrees of arthrosis may occur depending on the severity of the bunion, the duration of the bunion and the activity level. In my clinical experience, a long first metatarsal with massive subluxation of the big toe joint results in less destructive arthrosis. This is because the first metatarsal head of the joint is not articulating anymore and therefore gets spared from biomechanical “wear.” The cartilage itself is of poorer quality because of the loss of normal mechanics of the big toe joint.
Significant arthrosis of the big toe joint may not respond well to realignment of the joint with reconstruction. In general, my experience has demonstrated that even with the best realignment/reconstruction, the first MPJ will lose a fair amount of motion with severe bunion reconstruction so the presence of some radiographic arthrosis does not become a functional limiting factor. The biggest issue is whether the joint is supple enough to be relocated. However, end-stage arthrosis of the big toe joint (Stage IV) is best served with a joint destructive procedure of the first MPJ and this may also require a Lapidus to treat concomitant hypermobility.
A severe subluxed second toe secondary to overload may present a challenge when considering Lapidus for the severe bunion. Lesser toe problems are well known to occur with severe bunion deformities and may originate from overload and the hallux under-riding the second toe. A severely dislocated second toe often requires a lesser metatarsal osteotomy with digital repair and, depending on the extent of the reconstruction, may require postoperative non-weightbearing. Since one can use the Lapidus with an early weightbearing program, the limiting factor for a patient to go forward with a reconstruction is the non-weightbearing component of the lesser toe reconstruction.
Initiating An Early Weightbearing Program With A Lapidus Bunionectomy
In regard to determining which patients you should allow to begin an early weightbearing program, exact guidelines have yet to be established. However, an early weightbearing program does not affect the indications for Lapidus arthrodesis.
Patients who have an increased risk for complications should avoid early weightbearing or bear weight cautiously. Patients (such as smokers) who have an increased risk for nonunion may not be good candidates for early weightbearing but this is not an absolute contraindication. Obese patients are not great candidates for early weightbearing due to the force that can pass through the fusion site and lead to fixation failure. Do not enroll neuropathic patients in an early weightbearing program for similar reasons. Osteopenic patients with poor bone stock are also poor candidates.