NOTCHING OF ANTERIOR FEMORAL CORTEX AND RISK OF PERIPROSTHETIC FRACTURES AFTER TOTAL KNEE ARTHROPLASTY

Introduction Peri-prosthetic fractures after total knee and hip arthro- plasty have been reported with an increased incidence in the recent years. Although definite risk factors, beside a reduced BMD and high co-mor- bidity, are yet to be identified, it has been suggested that a violation of the anterior femoral cortex in the positioning of total knee arthroplasty (TKA) may increase the risk of sovracondylar fractures in operated knees. Aim of this study was to assess the incidence of femoral fractures in patients undergoing TKA with or without anterior femoral notching. Materials and methods We retrospectively analysed postoperative radiographs of 160 patients who underwent TKA. Forty-six of these (29 %) showed an anterior notching of femoral cortex, the entity of which was assessed in 4 degrees according to Tayside classification. A minimum of 5 years after surgery (range 5–8 years), patients were asked if they had had any trauma, with or without fractures, during the follow-up period at the operated or contralateral limb. Results Of the 46 patients included in the study, the anterior femoral notching was classified as grade I in 28 cases, grade II in 13 and grade III in 5. In no patient a grade 4 notching was observed. No peri- prosthetic fractures was reported by any patient, although 3 of them had an early orthopaedic visit due to a trauma in the operated limb. Discussion Anterior notching of femoral cortex may occur inadver- tently or deliberately, the latter to avoid the use of a large size with femoral condyles overhanging to restore the posterior condylar offset. In this respect it may be useful to assess the medium and long-term clinical history of patients with notching of the anterior femoral cortex. Conclusions The results of present investigation have shown that grade I to III of anterior femoral notching does not increase the incidence of periprosthetic fracture at medium term follow-up after TKA.