Epiphyseal-entry cannulated screws for temporary guided growth of the knees: a retrospective review of 89 cases

Abstract

Guided growth affects the physis in children to produce a desired effect. Several devices achieve alteration of growth, including staples, plates, and screws. Complications can include device failures, failure to modulate growth as expected, and unintended physeal arrest. We present the results of a unique technique designed to minimize these complications. This was a retrospective review of guided growth at the knee at a single institution utilizing cannulated screws with epiphyseal-entry points. Each case was reviewed to determine the presence of complications related to guided growth, including implant breakage, implant pull-out or pull-through, iatrogenic physeal arrest, failure to modulate growth, and the incidence of revision surgeries. There were 89 patients who had 146 epiphyseal-entry guided growth procedures with a total of 221 4.5 mm cannulated screws. There were no iatrogenic physeal arrests. Five (2.26%) screws in 4 (4.49%) patients had either a broken screw or screw pull-out/pull-through requiring revision procedures. Three patients had osteotomies after skeletal maturity. Four had revision-guided growth for other reasons: 2 due to a lack of timely follow-up, 1 for iatrogenic genu varum without implant failure, and 1 due to recurrent deformity after implant removal. Revision procedures were unanticipated in 6 (6.74%) patients. This study describes a technique for placing cannulated screws at the knee with epiphyseal starting points. Our rate of complications and number of revision surgeries compare favorably with those noted for other techniques. Guided growth using epiphyseal-entry cannulated screws is a safe, effective option for most patients.