Case Report of an Osteochondral Lesion of the First Metatarsal Head in an Adolescent Patient Treated by Autograft Mosaicplasty: Surgical Technique and Decision-Making Rationale

INTRODUCTION: First metatarsophalangeal (MTP) joint mobility is critical to a normal gait pattern; therefore, osteochondral defects (OCDs) of the first metatarsal head should be treated promptly to avoid functional limitation and progression to hallux rigidus. <15 cases of OCDs of the first MTP joint in the pediatric population, predominantly adolescents, have been published so far. The purpose of this article is to present a rare case of an adolescent first MTP joint OCD treated by the technique of autograft osteochondral mosaicplasty, which has been commonly used for OCDs of the knee and talus but scarcely described for the first MTP joint. CASE REPORT: The case of a 13-year-old male futsal player with a post-traumatic 50 mm2 OCD of the first metatarsal head is presented. The Osteochondral Autograft Transfer System® (Arthrex Inc™, Naples, FL) was used to harvest a 10-mm diameter donor plug from the medial ipsilateral femoral condyle, then delivered to the first metatarsal head. At the 6-month follow-up, physical activity had been resumed with no pain or significant mobility limitation and an improvement of the American Orthopedic Foot and Ankle Society hallux score of 54–95 points. At the same time, a follow-up magnetic resonance showed complete incorporation of the osteochondral graft without bone edema or subchondral osteonecrosis. CONCLUSION: Treatment for osteochondral lesions, regardless of their location, aims to restore function by recreating the articular congruity reducing the potential for a progressive degenerative process. Multiple surgical treatment options exist for OCDs of the first metatarsal head. The treatment decision must take into consideration both patient factors and lesion factors. Based on this, a literature revision and treatment decision rationale are presented. This case demonstrated that an osteochondral transplant could be a reasonable treatment option for a traumatic, full-thickness OCD of the first metatarsal head in adolescent patients.