Why The Lapidus Bunionectomy Is The Best Procedure For Severe Bunions
- Volume 24 - Issue 12 - December 2011
- 49182 reads
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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.
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.