A bunion (hallux valgus) is a progressive foot deformity where the big toe drifts toward the smaller toes, causing the head of the first metatarsal bone to protrude outward. This bony prominence can become painful and inflamed, often making shoe-wearing difficult. The condition is fundamentally a structural misalignment of the foot, not just an overgrowth of bone. The Lapidus bunionectomy is a specific surgical technique designed to correct this underlying structural problem, making it effective for moderate to severe cases.
Understanding Bunion Deformity and Instability
The visible bump of a bunion is a symptom of the first metatarsal bone shifting away from the foot’s midline (metatarsal drift). Traditional bunion procedures often address only the drift near the big toe joint, leading to a high rate of recurrence because the root cause remains uncorrected. The instability allowing this drift originates further back in the foot, at the first tarsometatarsal (TMT) joint, which connects the first metatarsal to the medial cuneiform bone.
When the TMT joint is unstable or hypermobile, it acts as a loose foundation, allowing the metatarsal to shift sideways and rotate with every step. This uncontrolled movement forces the big toe out of alignment. Procedures that correct only the end of the metatarsal, like an osteotomy, do not stabilize this foundation. The Lapidus procedure directly targets this foundational instability by permanently fusing the TMT joint.
The Lapidus Procedure Step-by-Step
The Lapidus bunionectomy uses arthrodesis, the surgical fusion of a joint. The goal is to establish a stable, corrected foundation for the first metatarsal. The surgeon accesses the TMT joint, where the first metatarsal meets the medial cuneiform bone. Cartilage is carefully removed from the opposing surfaces of these two bones to prepare them for fusion.
The first metatarsal is then rotated and repositioned back into its correct anatomical alignment, which corrects the sideway drift and rotation that created the bunion. The big toe joint is often realigned, sometimes requiring soft tissue adjustments to balance the tendons and ligaments. Securing the corrected joint with internal fixation, typically using specialized plates and screws, is the final step.
This hardware holds the bones rigidly together while the fusion process takes place, allowing the bones to grow together into a single, solid unit. Fusing the unstable TMT joint eliminates the hypermobility that caused the bunion. This stabilization provides long-term correction and significantly lowers the likelihood of the deformity returning compared to other types of bunion surgery.
Post-Operative Care and Recovery Timeline
Because the Lapidus bunionectomy involves fusing two bones, the post-operative recovery centers on allowing this solid bony union to occur. Patients must follow a strict non-weight-bearing protocol for the initial phase of recovery to prevent movement at the fusion site. This period typically lasts between six to eight weeks, during which time the patient must use crutches, a knee scooter, or a walker to remain completely off the operative foot.
During the first few weeks, the foot is protected in a splint or cast, and managing swelling through elevation is a primary focus. Once X-rays confirm early signs of bone healing, usually around the six-week mark, the patient transitions into a specialized walking boot. Even with a boot, the return to weight-bearing is gradual to protect the developing fusion, and the patient may still use crutches for support. Physical therapy often begins around the time of transition to the walking boot to restore range of motion in the big toe and strengthen the foot and ankle.
Full bone consolidation, known as union, generally takes between 10 to 12 weeks, though the timeline can vary. A complete recovery, including a return to high-impact activities and normal shoe wear, often takes three to six months. The longer recovery period is a trade-off for the procedure’s ability to provide a durable correction by addressing the underlying structural instability of the foot.