Medial malleolar screw versus tension-band plate hemiepiphysiodesis for ankle valgus in the skeletally immature.

BACKGROUND: Ankle valgus is frequently encountered in skeletally immature patients in association with a variety of musculoskeletal disorders. Guided growth with temporary medial malleolar transphyseal screw (MMS) hemiepiphysiodesis is an established surgical treatment capable of correcting the angular deformity, but is often complicated by symptomatic screw head prominence and difficult hardware removal. Tension-band plate (TBP) hemiepiphysiodesis has recently been advocated as an alternative; however, the relative efficacy of these 2 techniques has not been directly investigated. Thus, the purpose of this study was to compare MMS and TBP in treatment of pediatric ankle valgus deformity.

METHODS: Medical records and radiographs of all patients undergoing distal tibial medial hemiepiphysiodesis for ankle valgus between January 1, 2005 and November 1, 2010 at a pediatric orthopaedic specialty hospital were retrospectively reviewed. Radiographs obtained preoperatively and at 6-month intervals postoperatively were reviewed and the tibiotalar angle was measured. Patient age, sex, underlying diagnosis, concurrent surgical procedures, surgical and postoperative complications, and the presence or absence of symptomatic hardware complaints were documented.

RESULTS: Sixty ankles in 42 patients met the inclusion criteria, with adequate radiographs and minimum postoperative follow-up of 12 months (mean: 34 mo). Thirty-five ankles were treated with MMS, and 25 with TBP. Good mean correction of the tibiotalar angle was achieved in both groups (MMS: pre-77.1 degrees to post-87.8 degrees over 25.2 mo; TBP: pre-81.3 to post-87.6 over 20.0 mo). The mean rate of correction was faster in ankles treated with MMS than TBP, but differences did not reach statistical significance (0.55 vs. 0.36 degrees/mo, respectively; P=0.057). Complications included 6 hardware-related surgical complications in MMS ankles (17.1%) and 1 in TBP ankles (4.0%). The incidence of symptomatic hardware complaints was low in both groups (MMS, 5.7%; TBP, 0%).

CONCLUSIONS: Both MMS and TBP techniques can result in successful correction of ankle valgus in the growing child. Although the rate of deformity correction may be faster with MMS, TBP seems to be associated with fewer hardware-related complications. This information may aid the clinician in selecting the surgical option most appropriate for each individual patient.

LEVEL OF EVIDENCE: Level II-retrospective study.