Guided Growth With Temporary Hemiepiphysiodesis to Treat Ankle Valgus in a Skeletally Immature Individual: A Case Report

Hemiepiphysiodesis Using a Transphyseal Screw at the Medial Malleolus for the Treatment of Ankle Valgus Deformity

Background:

The purpose of this study is to report outcomes of transphyseal screw hemi-epiphysiodesis at the medial malleolus for the treatment of valgus ankle deformity.

Methods:

An institutional review board–approved retrospective review was done of 24 patient charts. Lateral distal tibial angle (LDTA) was measured preoperatively and at final follow-up.

Results:

The average change in LDTA was 8.3 degrees (SD 4.9 degrees; range 0-19 degrees). The average rate of correction was 0.4 degrees per month (SD 0.3; range 0-1.4).

Conclusion:

Medial malleolar transphyseal screw hemiepiphysiodesis is a simple, effective, and safe treatment for valgus ankle deformity in skeletally immature children.

Level of Evidence:

Level IV, case series.

Regenerative Medicine Approaches for the Treatment of Pediatric Physeal Injuries

The physis, or growth plate, is a cartilaginous region at the end of children's long bones that serves as the primary center for longitudinal growth and characterizes the immature skeleton. Musculoskeletal injury, including fracture, infection, malignancy, or iatrogenic damage, has risk of physeal damage. Physeal injuries account for 30% of pediatric fractures and may result in impaired bone growth. Once damaged, cartilage tissue within the physis is often replaced by unwanted bony tissue, forming a "bony bar" that can lead to complications such as complete growth arrest, angular or rotational deformities, and altered joint mechanics. Children with a bony bar occupying <50% of the physis usually undergo bony bar resection and insertion of an interpositional material, such as a fat graft, to prevent recurrence and allow the surrounding uninjured physeal tissue to restore longitudinal bone growth. Clinical success for this procedure is <35% and often the bony bar and associated growth impairments return. Children who are not candidates for bony bar resection due to a physeal bar occupying >50% of their physis undergo corrective osteotomy or bone lengthening procedures. These approaches are complex and have variable success rates. As such, there is a critical need for regenerative approaches to not only prevent initial bony bar formation but also regenerate healthy physeal cartilage following injury. This review describes physeal anatomy, mechanisms of physeal injury, and current treatment options with associated limitations. Furthermore, we provide an overview of the current research using cell-based therapies, growth factors, and biomaterials in the different animal models of injury along with strategic directions for modulating intrinsic injury pathways to inhibit bony bar formation and/or promote physeal tissue formation. Pediatric physeal injuries constitute a unique niche within regenerative medicine for which there is a critical need for research to decrease child morbidity related to this injurious process.