Percutaneous epiphysiodesis using transphyseal screws (PETS)

We describe a new technique of percutaneous epiphysiodesis using transphyse al screws (PETS) and our experience with it in 32 cases of limb-length ineq uality and nine angular knee deformities. A subgroup of 18 patients with po stfracture limb overgrowth formed a clinical model for study of the real ef ficacy of PETS. It proved a reliable method with few complications and many advantages such as simplicity of technique, short operating time, rapid po stoperative rehabilitation, and reversibility. Bone-length inequality decre ased from a preepiphysiodesis average of 2.47 cm (range, 1.5-4.6) to 0.51 c m at skeletal maturity. The tibiofemoral angle reduced from a preoperative average of 7.66 degrees to 0.86 degrees at maturity. The screws began to ex ert significant growth inhibition within 6 months of insertion, slowing dow n the distal femoral and upper tibial physes by 68 and 56%, respectively. T hey achieved maximum growth retardation over the ensuing 12 months, slowing down the distal femoral physis by 89% and the proximal tibial physis by 95 %. At skeletal maturity, total femoral growth was 45% and total tibial grow th was 52% that of the normal side.