Vicente Sanchis-Alfonso1,2, Cristina Ramirez-Fuentes3, Erik Montesinos-Berry4, Julio Domenech5, Luis Martí-Bonmatí3. 1. Hospital 9 de Octubre, Valencia, Spain. vicente.sanchis.alfonso@gmail.com. 2. Hospital Arnau de Vilanova, Valencia, Spain. vicente.sanchis.alfonso@gmail.com. 3. Department of Radiology, Hospital Universitario y Politécnico La Fe and GIBI230 IIS La Fe Research Group, Valencia, Spain. 4. Agoriaz Orthopedic Center, Riaz, Switzerland. 5. Hospital Arnau de Vilanova, Valencia, Spain.
Abstract
PURPOSE: This study's purpose was to investigate how an ideal anatomic femoral attachment affects the dynamic length change pattern of a virtual medial patellofemoral ligament (MPFL) from an extended to a highly flexed knee position; to determine the relative length and length change pattern of a surgically reconstructed MPFL; and to correlate femoral attachment positioning, length change pattern, and relative graft length with the clinical outcome. METHODS: Twenty-four knees with isolated nonanatomic MPFL reconstruction were analysed by three-dimensional computed tomography at 0°, 30°, 60°, 90°, and 120° of knee flexion. The lengths of the MPFL graft and a virtual anatomic MPFL were measured. The pattern of length change was considered isometric if the length distance changed <5 mm through the entire dynamic range of motion. RESULTS: Knee flexion significantly affected the path lengths between the femoral and patellar attachments. The length of the anatomic virtual MPFL decreased significantly from 60° to 120°. Its maximal length was 56.4 ± 6.8 mm at 30°. It was isometric between 0° and 60°. The length of the nonanatomic MPFL with a satisfactory clinical result decreased during flexion from 0° to 120°. Its maximal length was 51.6 ± 4.6 mm at 0° of knee flexion. The lengths measured at 0° and 30° were isometric and statistically greater than the lengths measured at higher flexion degrees. The failed nonanatomic MPFL reconstructions were isometric throughout the dynamic range, being significantly shorter (27.1 ± 13.3 %) than anatomic ligaments. CONCLUSION: The femoral attachment point significantly influences the relative length and the dynamic length change of the grafts during knee flexion-extension and graft isometry. Moreover, it influences the long-term outcome of the MPFL reconstructive surgery. A nonanatomic femoral fixation point should not be considered the cause of persistent pain and instability after MPFL reconstruction in all cases. LEVEL OF EVIDENCE: III.
PURPOSE: This study's purpose was to investigate how an ideal anatomic femoral attachment affects the dynamic length change pattern of a virtual medial patellofemoral ligament (MPFL) from an extended to a highly flexed knee position; to determine the relative length and length change pattern of a surgically reconstructed MPFL; and to correlate femoral attachment positioning, length change pattern, and relative graft length with the clinical outcome. METHODS: Twenty-four knees with isolated nonanatomic MPFL reconstruction were analysed by three-dimensional computed tomography at 0°, 30°, 60°, 90°, and 120° of knee flexion. The lengths of the MPFL graft and a virtual anatomic MPFL were measured. The pattern of length change was considered isometric if the length distance changed <5 mm through the entire dynamic range of motion. RESULTS: Knee flexion significantly affected the path lengths between the femoral and patellar attachments. The length of the anatomic virtual MPFL decreased significantly from 60° to 120°. Its maximal length was 56.4 ± 6.8 mm at 30°. It was isometric between 0° and 60°. The length of the nonanatomic MPFL with a satisfactory clinical result decreased during flexion from 0° to 120°. Its maximal length was 51.6 ± 4.6 mm at 0° of knee flexion. The lengths measured at 0° and 30° were isometric and statistically greater than the lengths measured at higher flexion degrees. The failed nonanatomic MPFL reconstructions were isometric throughout the dynamic range, being significantly shorter (27.1 ± 13.3 %) than anatomic ligaments. CONCLUSION: The femoral attachment point significantly influences the relative length and the dynamic length change of the grafts during knee flexion-extension and graft isometry. Moreover, it influences the long-term outcome of the MPFL reconstructive surgery. A nonanatomic femoral fixation point should not be considered the cause of persistent pain and instability after MPFL reconstruction in all cases. LEVEL OF EVIDENCE: III.
Authors: Hui Jun Kang; Fei Wang; Bai Cheng Chen; Yan Ling Su; Zhan Chi Zhang; Chang Bao Yan Journal: Knee Surg Sports Traumatol Arthrosc Date: 2010-03-16 Impact factor: 4.342
Authors: Christopher L Camp; Aaron J Krych; Diane L Dahm; Bruce A Levy; Michael J Stuart Journal: Am J Sports Med Date: 2010-08-17 Impact factor: 6.202
Authors: Juan C Monllau; Juan I Erquicia; Maximiliano Ibañez; Pablo E Gelber; Federico Ibañez; Angel Masferrer-Pino; Xavier Pelfort Journal: Arthrosc Tech Date: 2017-09-04
Authors: Vicente Sanchis-Alfonso; Erik Montesinos-Berry; Cristina Ramirez-Fuentes; Joan Leal-Blanquet; Pablo E Gelber; Joan Carles Monllau Journal: World J Orthop Date: 2017-02-18