The Clinical Results of Morscher Hook-Screw for the Treatment of Lumbar Spondylolysis

This is a retrospective study to evaluate the clinical outcome of patients who, while undergoing repair of pars defects, were treated with the Morscher hook-screw. Ten patients were included in this study. All patients had Type IIA spondylolytic defects with either a Grade 0 or less than Grade I spondylolisthesis. One surgeon performed the operation with a follow-up period, which lasted at least two years. The clinical results were evaluated by Henderson score system and each patient improved an average of 1.5 grade. Radiographic analysis showed failure of healing in 4 patients, and solid fusion of the pars defects in 6 of 10 patients (60%). One case with double level L3 and L5, which showed fusion at L3 and non-union at L5. Three patients revealed radiographic non-union of fracture site, and received a removal of implant, during which we observed a fibrous-union of fracture site but without any formation of pseudoarthrosis. This technique is a simple and effective method for direct repair of spondylolysis. It is only indicated in the case of young ages with pure spondylolysis and slippage of a slight degree.