Shuji Nakagawa1, Yuji Arai2, Hiroaki Inoue3, Manabu Hino3, Yuta Fujii3, Shintaro Komaki3, Kazuya Ikoma3, Keiichiro Ueshima3, Hiroyoshi Fujiwara3, Toshikazu Kubo3. 1. Department of Sports and Para-Sports Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. 2. Department of Sports and Para-Sports Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto, 602-8566, Japan. yarai89046@nike.eonet.ne.jp. 3. Department of Orthopaedics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Abstract
PURPOSE: Recurrent patellar dislocation is currently treated with anatomical reconstruction of the medial patellofemoral ligament (MPFL), and favourable postoperative outcomes have been reported. However, it is uncertain if healthy MPFL function is restored by anatomical reconstruction. The hypothesis in this study was that stabilization of the patella following MPFL reconstruction would be improved compared with that before surgery, but that function of the grafted tendon would differ from that of a healthy MPFL. The objective was to analyse the length change patterns of the MPFL before surgery and the grafted tendon after surgery in patients with recurrent patellar dislocation treated with anatomical MPFL reconstruction. METHODS: The subjects were 12 patients (13 knees) in whom recurrent patellar dislocation was treated with anatomical MPFL reconstruction. The length change patterns of the MPFL and reconstructed ligament were analysed at extension and flexion of the knee joint using open MRI. RESULTS: The postoperative grafted tendon length was significantly shorter than that of the preoperative MPFL at knee extension, and significantly longer at 90° and 120° of knee flexion. The postoperative length of the grafted tendon only changed slightly from 0° to 30° of knee flexion, and then significantly decreased at flexion of 30° or more. The morphology of the grafted tendon was linear until 60° knee flexion, but became convex toward the extraarticular side at flexion of 90° or more. CONCLUSION: The grafted tendon length at knee extension was shorter than that of the preoperative MPFL, but there was no significant difference at 30° flexion. These findings suggest that the effect of damping of the patella with a grafted tendon after MPFL reconstruction may differ from that in a healthy knee. In addition, the morphology at 60° knee flexion was improved to linear after surgery, suggesting that ligament morphology at this flexion was normalized by MPFL reconstruction. LEVEL OF EVIDENCE: III.
PURPOSE: Recurrent patellar dislocation is currently treated with anatomical reconstruction of the medial patellofemoral ligament (MPFL), and favourable postoperative outcomes have been reported. However, it is uncertain if healthy MPFL function is restored by anatomical reconstruction. The hypothesis in this study was that stabilization of the patella following MPFL reconstruction would be improved compared with that before surgery, but that function of the grafted tendon would differ from that of a healthy MPFL. The objective was to analyse the length change patterns of the MPFL before surgery and the grafted tendon after surgery in patients with recurrent patellar dislocation treated with anatomical MPFL reconstruction. METHODS: The subjects were 12 patients (13 knees) in whom recurrent patellar dislocation was treated with anatomical MPFL reconstruction. The length change patterns of the MPFL and reconstructed ligament were analysed at extension and flexion of the knee joint using open MRI. RESULTS: The postoperative grafted tendon length was significantly shorter than that of the preoperative MPFL at knee extension, and significantly longer at 90° and 120° of knee flexion. The postoperative length of the grafted tendon only changed slightly from 0° to 30° of knee flexion, and then significantly decreased at flexion of 30° or more. The morphology of the grafted tendon was linear until 60° knee flexion, but became convex toward the extraarticular side at flexion of 90° or more. CONCLUSION: The grafted tendon length at knee extension was shorter than that of the preoperative MPFL, but there was no significant difference at 30° flexion. These findings suggest that the effect of damping of the patella with a grafted tendon after MPFL reconstruction may differ from that in a healthy knee. In addition, the morphology at 60° knee flexion was improved to linear after surgery, suggesting that ligament morphology at this flexion was normalized by MPFL reconstruction. LEVEL OF EVIDENCE: III.
Entities:
Keywords:
Length change pattern; Medial patellofemoral ligament; Open MRI; Reconstruction
Authors: Petri J Sillanpää; Ville M Mattila; Tuomo Visuri; Heikki Mäenpää; Harri Pihlajamäki Journal: Knee Surg Sports Traumatol Arthrosc Date: 2010-10-07 Impact factor: 4.342
Authors: Rick P Csintalan; L Daniel Latt; Stefan Fornalski; Kian Raiszadeh; Maria Cs Inacio; Donald C Fithian Journal: J Knee Surg Date: 2013-11-13 Impact factor: 2.757