Effects of tension band plating on coronal plane alignment of lower extremities in children treated for idiopathic limb length discrepancy.

Purpose: One of the most common treatment methods for moderate limb length discrepancy in children is growth modulation using tension band plating. Coronal plane deformities after tension band plating for limb length discrepancy have been documented as an important complication in articles involving heterogeneous groups consisted of both idiopathic cases and patients with pathological physes. The aim of the study was to determine the rate of coronal plane deformities after treatment of a homogeneous group of idiopathic limb length discrepancy cases with tension band plating and to compare screw constructs of medial and lateral plates. Methods: Patient files were retrospectively reviewed for amount of limb length discrepancy, anatomical femorotibial angle, mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, and inter-screw angles of each plate on both sides of the tibiae and femora. Measurements at each follow-up period were compared to each other. Results: A total of 26 patient files (37 bones) were included to the study. The mean age was 10.5 years. The mean limb length discrepancy was 27.5 mm. Implants were removed after mean 34.5 months. The mean follow-up period was 58.5 months. There was no significant difference in inter-screw angle on each side of the bones at the time of implantation and in lower limb alignments during follow-up. Conclusion: Treatment of mild-to-moderate idiopathic limb length discrepancy with tension band plating in children was found to be safe against any coronal plane deformity during follow-up until skeletal maturity. Level of evidence: Level IV.

Rebound Deformity After Growth Modulation in Patients With Coronal Plane Angular Deformities About the Knee: Who Gets It and How Much?

BACKGROUND: With observed success and increased popularity of growth modulation techniques, there has been a trend toward use in progressively younger patients. Younger age at growth modulation increases the likelihood of complete deformity correction and need for implant removal before skeletal maturity introducing the risk of rebound deformity. The purpose of this study was to quantify magnitude and identify risk factors for rebound deformity after growth modulation. METHODS: We performed a retrospective review of all patients undergoing growth modulation with a tension band plate for coronal plane deformity about the knee with subsequent implant removal. Exclusion criteria included completion epiphysiodesis or osteotomy at implant removal, ongoing growth modulation, and <1 year radiographic follow-up without rebound deformity. Mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, hip-knee-ankle angle (HKA), and mechanical axis station were measured before growth modulation, before implant removal, and at final follow-up. RESULTS: In total, 67 limbs in 45 patients met the inclusion criteria. Mean age at growth modulation was 9.8 years (range, 3.4 to 15.4 y) and mean age at implant removal was 11.4 years (range, 5.3 to 16.4 y). Mean change in HKA after implant removal was 6.9 degrees (range, 0 to 23 degrees). In total, 52% of patients had >5 degrees rebound and 30% had >10 degrees rebound in HKA after implant removal. Females below 10 years and males below 12 years at time of growth modulation had greater mean change in HKA after implant removal compared with older patients (8.4 vs. 4.7 degrees, P=0.012). Patients with initial deformity >20 degrees had an increased frequency of rebound >10 degrees compared with patients with less severe initial deformity (78% vs. 22%, P=0.002). CONCLUSIONS: Rebound deformity after growth modulation is common. Growth modulation at a young age and large initial deformity increases risk of rebound. However, rebound does not occur in all at risk patients, therefore, we recommend against routine overcorrection. LEVEL OF EVIDENCE: Level IV-retrospective study.

Nonoperatively Corrected Clubfoot at Age 2 Years: Radiographs Are Not Helpful in Predicting Future Relapse.

BACKGROUND: Nonoperative treatment of idiopathic clubfoot is standard. The purpose of this study was to determine if measurements made on standing lateral radiographs of successfully treated clubfeet made at 18 to 24 months of age were predictive of late recurrence. METHODS: Inclusion criteria were idiopathic clubfoot with an age at presentation of ≤3 months, nonoperative treatment resulting in a clinically plantigrade foot at 2 years of age, standing lateral radiograph of the involved foot made at 18 to 24 months of age, and a minimum age of 4 years at the time of follow-up. The radiographs were assessed for the talocalcaneal angle and the tibiocalcaneal angle, with measurements made by 2 trained practitioners. The average values of the 2 raters were used. The interobserver reliability was calculated using intraclass correlation coefficients (ICCs). A total of 211 patients with 312 clubfeet were evaluated. The average age at the time of follow-up was 8.0 years (range, 4.0 to 13.3 years). Results at the time of follow-up were rated as good (maintained plantigrade foot), fair (required limited surgery to maintain, or return to, a plantigrade position), or poor (required posteromedial release). RESULTS: Over time, 75% of the feet had a good result, 19% had a fair result, and 6% had a poor result. With regard to radiographic assessment, the ICCs were 0.97 (talocalcaneal angle) and 0.98 (tibiocalcaneal angle), demonstrating excellent agreement between the raters. The mean talocalcaneal angle differed significantly between the feet with a good clinical outcome and those with a fair outcome (28° versus 24°; p < 0.02), but did not differ significantly between those with a good versus poor outcome (28° versus 26°), or a fair versus poor outcome (24° versus 26°). There were no significant differences in the mean tibiocalcaneal angle among the groups (86°, 90°, and 84°, respectively) (p = 0.17). CONCLUSIONS: Most clubfeet that were clinically plantigrade at 2 years of age remained so, while one-fourth subsequently required some surgery for late recurrence, primarily limited procedures. The tibiocalcaneal angle and talocalcaneal angle from standing lateral radiographs made at 18 to 24 months of age were not helpful in predicting future relapse. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.