Abstract
Objectives:
The purpose of this study was to evaluate the effect of tibial tubercle-sparing anterior closing-wedge osteotomy on patellar height in revision ACL reconstructions (ACLR).
Methods:
Patients who underwent arthroscopic revision ACLR combined with retro-tibial tubercle anterior closing wedge high tibial osteotomy (ACW-HTO) from 01/01/2016 to 31/03/2021 were assessed for eligibility. Patellar height was measured on full weightbearing lateral x-rays according to the Insall-Salvati index (ISI) and Caton-Deschamps index (CDI) or frontal x-rays using the Femoral Patellar Height Index (FPHI). The PTS was evaluated using the proximal anatomic axis of the tibia on standard short lateral x-rays. The delta (post-operative - preoperative) and the ratio (pre-operative / post-operative) of the three patellar height indices and PTS were calculated. Preoperative to postoperative patellar height were compared using independent t tests for each index. It was also investigated whether patients changed patellar height category (baja, norma, or alta).
Results:
Among 475 revision ACLR, 47 tibial tubercle-sparing ACW-HTOs were performed. No significant difference in patellar height was found between pre- and postoperative x-rays regardless of the index (ISI P = .1729, CDI P = .4034, FPHI P = .5130). Despite the lack of a statistically significant difference, 15 patients (31.9%) exhibited a post-operative change in their patellar height category when measured by the ISI (6 moved up a category, 9 moved down a category) and 18 (38.3%) patients changed category according to the CDI (10 moved up a category, 8 moved down a category).
Conclusions:
Although a statistically significant difference between pre- and postoperative patella height was not observed, changes in patellar height category were common after tibial tubercle-sparing anterior closing-wedge high tibial osteotomy, in patients undergoing revision ACL reconstruction. The clinical impact of these changes is unknown and further study is needed to investigate whether they may result in patellofemoral symptoms.