Pediatric proximal tibia metaphyseal fractures that are minimally displaced are also named Cozen fractures. They heal reliably but often progress to a valgus deformity. The valgus deformity seen with Cozen fractures is secondary to an increase in metaphyseal growth medially and are treated with observation as they almost always spontaneously correct over time.
Zionts et al peformed a retrospective review of 7 patients with Cozen fractures and found that the valgus angulation progressed most rapidly during the first year after the injury, and then continued at a slower rate for as long as seventeen months.
Tuten et al then re-reviewed this same cohort at 15 year followup and found that the valgus angulation completely resolved in 100% of cases. However, the affected tibia was longer than the contralateral tibia in 100% of cases with an average limb-length discrepancy of 9 mm.
Tuten HR, Keeler KA, Gabos PG, Zionts LE, MacKenzie WG. Posttraumatic tibia valga in children. A long-term follow-up note. J Bone Joint Surg Am. 1999 Jun;81(6):799-810.
PMID:10391545 (Link to Abstract)
Zionts LE, MacEwen GD. Spontaneous improvement of post-traumatic tibia valga. J Bone Joint Surg Am. 1986 Jun;68(5):680-7
PMID:3722224 (Link to Abstract)
Herring JA (Ed): Tachdjan's Pediatric Orthopaedics, Ed 3. Philadelphia , PA, WB Saunders, 2002, PP 839-890