Closing the tendon defect does not affect tendon length and patellar height after bone-patellar tendon-bone ACL reconstruction. A retrospective study using radiographs

PURPOSE: The aim of this study was to compare radiological changes in patellar height (PH) and patellar tendon length (PTL) after closure and non-closure of the patellar donor site defect during anterior cruciate ligament reconstruction (ACLR) using a bone-patellar tendon-bone (BPTB) autograft. METHODS: In this retrospective study a total of 63 patients was included. All patients underwent an arthroscopically assisted ACLR using the mid-third BPTB autograft. In 30 patients the tendon donor site defect was closed. In 33 patients the tendon donor site defect was left open. The paratenon was approximated in all patients. Lateral radiographs were taken preoperatively and at 3 months after ACLR. PH was determined using the Insall-Salvati, Caton-Deschamps and Blackburne-Peel methods. PTL was measured by determining the distance between the inferior pole of the patella and the superior aspect of the tibial tubercle. RESULTS: Overall, no change in patellar height were observed 3 months after ACLR for the Insal-Salvati (p = 0.54), Caton-Deschamps (p = 0.75) and Blackburne-Peel methods (p = 0.83). Also, the change in pre- and postoperative patellar height did not differ between the closure- and non-closure-group for the Insall-Salvati (p = 0.77), the Caton-Deschamps (p = 0.89) and the Blackburne-Peel (p = 0.70) methods. Overall, no significant change in PTL was observed 3 months after ACLR (p = 0.78). Between both groups, no significant difference was observed for PTL over time (p = 0.98). CONCLUSION: Patellar height and patellar tendon length did not significantly change after anterior cruciate reconstruction using bone-patellar tendon-bone autografts regardless of patellar donor site closure. LEVEL OF EVIDENCE: IIIb.