The Surgical Learning Curve for Modified Lapidus Procedure for Hallux Valgus Deformity.

Background: Hallux valgus is one of the most common orthopaedic deformities of the foot, affecting as much as 23% of the population age 18 to 65. In addition to its high prevalence, it has a complex multifactorial pathogenesis. Surgical correction options have variable rates of success and new techniques are being developed. The modified Lapidus procedure attempts to correct in 3 planes of deformity, which may create a steeper learning curve for those newly adopting the technique.

Methods: A retrospective review was performed on patients who underwent hallux valgus reconstruction with a modified Lapidus procedure between March 2018 and July 2020. Exclusion criteria included revision surgery, 6 or more concurrent procedures, or a flexor digitorum longus tendon transfer for adult acquired flatfoot correction.

Results: There were a total of 81 modified Lapidus procedures for hallux valgus within the study time frame and 68 were included in the study. Over a period of 2 years there was a significant decrease in overall surgery duration from 78.93 minutes at month 0 to 61.80 minutes at 24 months (P = .036). The average preoperative/postoperative intermetatarsal angles were 15.08° and 4.91°, respectively. There was an average decrease of 10.17°. The rate of nonunion was 4.41% (3/68), and the rate of recurrence at 6 months was 5.88% (4/68). There was not a significant difference in the rate of recurrence (P = .394) or the rate of nonunion (P = .817) as the surgeon increased in experience.

Conclusion: Although there is a significant learning curve for the modified Lapidus procedure, it is largely overcome by the 23rd case. Additionally, experience with the technique does not appear to affect the patient outcomes of nonunion or recurrence.

Levels of evidence: Level IV: Retrospective.