Spontaneous patellar fracture in a soccer player occurred 3 years and 3 months after anterior cruciate ligament reconstruction with central third bone-patellar tendon–bone graft

Abstract

Dear Editor, We have read with great interest the article concerning patellar fractures associated with medial third bone-patellar tendon–bone autograft ACL reconstruction [7]. As reported in the article, this rare complication was reported by some authors. Viola et al. [10] reported three transverse patellar fractures between 8 and 12 weeks postoperatively. Berg [2] reported a patellar transverse fracture that occurred 4 months postoperatively after a minor fall while ascending stairs. Bonatus et al. [3] reported avulsion of one-half of the remaining patellar tendon from the tibia associated with patellar fracture in the eighth postoperative day. Benson et al. [1] reported a nondisplaced transverse avulsion fracture of the superior pole of the patella that occurred 1 year after ACL reconstruction. Miller et al. [6] reported a patellar fracture following slipping and falling down that occurred 6 weeks after BPTB anterior cruciate ligament reconstruction. Therefore it is clear that most of the described fractures happened during early postoperative period. In 2004 we reported in the Italian Society of Orthopaedics and Traumatology (S.I.O.T.) Journal [5] a similar case in which the patient, a 27-year-old professional football player, 3 years and 3 months (i.e. 1,185 days) after BPTB anterior cruciate ligament reconstruction, reported a transverse patellar fracture while he was kicking the ball. We feel this case is unique, because literature reports an average time of 57 days for patellar fractures following BPTB anterior cruciate ligament reconstruction, with an interval between 24 and 121 days [8]. Moreover this fracture happened in an atraumatic way, resulting from rapid flexion of the knee against a fully contracted quadriceps [9] despite the literature, especially reporting it in a traumatic way. These injured patellas are usually stabilized with tension band or conservatively (in your cases a rigid internal fixation in one case was preferred, whereas the other three cases were treated conservatively) [7] or with cannulated screws [6, 9]. Because patellar fractures synthesized with cannulated screws show lesser tendency to displace when compared to those synthesized with modified tension band or with cannulated screws plus the tension band [4] we decided to operate on the patellar fractures with two Herbert screws, with a vertical and a little convergent manner. In your cases rehabilitation was prolonged, whereas in our case, because of the sports activity of the patient, an aggressive rehabilitation was preferred. Actually our patient is very satisfied with the surgical outcome and plays football matches with valuable results.