Eight-plates are used to correct varus-valgus deformity (VVD) or limb-length discrepancy (LLD) in children and adolescents. It was reported that these implants might create a bony deformity within the knee joint by change of the roof angle (RA) after epiphysiodesis of the proximal tibia following a radiological assessment limited to anteroposterior (AP) radiographs. The aim of this study was to analyze the RA, complemented with lateral knee radiographs, with focus on the tibial slope (TS) and the degree of deformity correction. A retrospective, single-centre study was conducted. The treatment group (n = 64 knees in 44 patients) was subclassified according to the implant location in two groups: 1) medial hemiepiphysiodesis; and 2) lateral hemiepiphysiodesis. A third control group consisted of 25 untreated knees. The limb axes and RA were measured on long standing AP leg radiographs. Lateral radiographs of 40 knees were available for TS analysis. The mean age of the patients was 10.6 years (4 to 15) in the treatment group and 8.4 years (4 to 14) in the control group. Implants were removed after a mean 1.2 years (0.5 to 3).Aims
Methods
Percutaneous epiphysiodesis using transphyseal
screws (PETS) has been developed for the treatment of lower limb discrepancies
with the aim of replacing traditional open procedures. The goal
of this study was to evaluate its efficacy and safety at skeletal
maturity. A total of 45 consecutive patients with a mean skeletal
age of 12.7 years (8.5 to 15) were included and followed until maturity.
The mean efficacy of the femoral epiphysiodesis was 35% (14% to 87%)
at six months and 66% (21% to 100%) at maturity. The mean efficacy
of the tibial epiphysiodesis was 46% (18% to 73%) at six months
and 66% (25% to 100%) at maturity. In both groups of patients the
under-correction was significantly reduced between six months post-operatively
and skeletal maturity. The overall rate of revision was 18% (eight
patients), and seven of these revisions (87.5%) involved the tibia.
This series showed that use of the PETS technique in the femur was
safe, but that its use in the tibia was associated with a significant
rate of complications, including a valgus deformity in nine patients
(20%), leading us to abandon it in the tibia. The arrest of growth
was delayed and the final loss of growth at maturity was only 66%
of that predicted pre-operatively. This should be taken into account
in the pre-operative planning.
A total of 25 children (37 legs and 51 segments) with coronal plane deformities around the knee were treated with the extraperiosteal application of a flexible two-hole plate and screws. The mean age was 11.6 years (5.5 to 14.9), the median angle of deformity treated was 8.3° and mean time for correction was 16.1 months (7 to 37.3). There was a mean rate of correction of 0.7° per month in the femur (0.3° to 1.5°), 0.5° per month in the tibia (0.1° to 0.9°) and 1.2° per month (0.1° to 2.2°) if femur and tibia were treated concurrently. Correction was faster if the child was under 10 years of age (p = 0.05). The patients were reviewed between six and 32 months after plate removal. One child had a rebound deformity but no permanent physeal tethers were encountered. The guided growth technique, as performed using a flexible titanium plate, is simple and safe for treating periarticular deformities of the leg.
