Purpose Angular deformities of the knee resulting from idiopathic, congenital, or acquired causes are commonly encountered in pediatric orthopedics. Whereas physiological deformities should be treated expectantly, the remaining often progress enough to warrant operative treatment, despite attempted bracing. Historical methods of surgical treatment (e.g., epiphysiodesis and stapling) have yielded to the increasingly popular method of reversible guided growth using the eight-Plate. Methods We studied 58 patients with knee angular deformities managed with eight-Plate guided growth. All etiologies except physiological deformities and those with very slow growth rate were included. Each patient was under appropriate medical management during the entire duration of treatment and after plate removal. Results In the dysplasia/syndrome group, we noted complete correction in 22 patients (78.5%), partial correction in 5 (17.9%), and no correction in 1 patient (3.6%). All cases of idiopathic deformities resolved. Patients with osteochondral dysplasias and genetic syndromes underwent earlier intervention and slower correction than those with idiopathic genu varum or valgum. The time difference in reaching a neutral mechanical axis between the two groups (11 months in idiopathic versus 18 months in pathological physis) could be explained by a significant difference in growth speeds (P = 0.003). Conclusion Results indicate that early intervention is advisable for patients with osteochondral dysplasias/syndromes as subsequent correction takes longer. If rebound growth causing recurrent deformity occurs, guided growth can be safely repeated. Additionally, complications reported with other techniques such as hardware failure, physeal violation by the implant, premature physeal closure, and overcorrection were not reported while using the eight-Plate.

Implantable intramedullary nail lengthening devices (e.g., PRECICE 2 system) have been proposed as alternative method to external fixation for lower limb lengthening surgery. The aim of this study was to analyse our outcomes and complications using the PRECICE 2 (P2) nail system and review them in light of the existing literature. A retrospective multicentre study was conducted on patients <18 years, who were treated for limb lengthening using the P2 system. The inclusion criteria were a limb length discrepancy ≥ 30 mm and a follow-up ≥6 months after the end of treatment. A total of 26 (15 males) patients were included, average age was 14.7 ± 2.3 years; 26 nails (21 femur, 5 tibia) were implanted. The average goal lengthening was 49.4 ± 12.4 mm, while average achieved lengthening was 44.4 ± 11.6 mm. Average distraction and consolidation indexes were 11.9 ± 2.1 days/cm and 25.1 ± 8.1 days/cm, respectively. Nail accuracy and reliability were 91.1% and 88.5%, respectively. A total of five problems (joint contractures), one obstacle (femur fracture) and three complications (hip joint subluxation, deep infection and nail running back) were encountered. The P2 nail system is a valid alternative to external fixator for limb lengthening in young patients with no significant angular or rotation deformities. Our study confirms a favourable complication rate and available evidence from literature suggests a lower complication rate than external fixator systems. Nevertheless, surgeons should keep a watchful eye on risk of joint subluxation and mechanical complications with intramedullary lengthening.

The aim of this study was to compare clinical and radiographical results for treatment of lower limb multiaxial deformities±limb length discrepancy (LLD) of at least 2 cm with the Truelok hexapod fixator system (TL-HEX). All consecutive cases of lower limb multiaxial deformities were included. Patients were divided in two groups: group 1, lower limb angular deformity+LLD less than 2 cm, and group 2, lower limb angular deformity+LLD of at least 2 cm. Only patients with age younger than or equal to 20 years and follow-up of 6 months after removal of the external fixator were included. A total of 27 (six femur and 39 tibia treated) and 20 patients (12 femur and 19 tibia) were enrolled in groups 1 and 2, respectively. Complete correction of the deformity was achieved in 90 and 96% of the patients in groups 1 and 2, respectively. There were no differences in terms of external fixator, maturation, and distraction indexes between the two groups and between different anatomical sites. Good to excellent functional results (ASAMI score) were obtained in 93% of patients in group 1 and 75% in group 2 (P=0.01). Complication rate was similar between the two groups (7.4 vs. 10%, respectively). Average follow-up after removal of the external fixator was 25.6 (range: 7.0–54.0) months. The TL-HEX external fixator system allows a predictable correction of complex lower limb deformities regardless of the presence of LLD. Although complication rate is similar between the two groups, lower functional outcomes can be expected in patients with significant preoperative LLD.