2023 ISAKOS Biennial Congress ePoster
A Magnetic Resonance Imaging Study of the Radiological Anatomy of the Patella: the Size of the Patella Correlates with Bone Bridge Between Tunnels and R Angles are Highlighted for Safe Tunnel Drilling During MPFL Reconstruction
Vasileios Raoulis, MD, PhD, LARISSA, Thessaly GREECE
ARISTIDIS ZIBIS
Apostolos Fyllos, MD, PhD, Larissa GREECE
Michail E. Klontzas, MD, PhD, Heraklion, Heraklion GREECE
Michael E. Hantes, MD, PhD, Prof., Larissa GREECE
Anatomy Department University of Thessaly, Larissa, Europe, GREECE
FDA Status Cleared
Summary
Small-size patellae correlate with short maximum bone bridge between tunnels, which makes anatomic, double-bundle, hardware-free patella fixation, with two semi-patellar tunnels MPFL reconstruction challenging. Furthermore, R angles create a narrow window to avoid intraoperative breaching, rendering the use of the ACL tibia device an extremely useful instrument. This has clinical applications for
ePosters will be available shortly before Congress
Abstract
Purpose
To measure the safe range of angles during tunnel drilling and to map ideal patella tunnel placement with the use of Magnetic Resonance Imaging (MRI) preoperatively in medial patellofemoral ligament (MPFL) reconstruction using a hardware-free patellar fixation technique with two semi-patellar tunnels.
Methods
Knee MRI scan were performed on 180 patients (94 female, 86 male patients, 85 left knees vs 95 right knees) with mean age 26.85 (range 14-45 years).Patellar measurements: L1 was the maximal patellar length. L2 was the minimum possible distance of placement for the upper tunnel from the proximal pole of the patella. The maximum bone bridge between tunnels was calculated as half of L1 minus the L2 distance (L1/2-L2). We also measured R1 and R2 angles at the proximal and distal tunnel that represent safe angles at the entry point during tunnel drilling (without breaching the anterior cortex or articular cartilage).
Results
Preoperatively, mean L1 was 4.04 cm (range 2.42-5.08). Mean L2 was 0.57 cm (range 0.46-0.89). The mean maximum possible bone bridge between tunnels (L1/2-L2) was 1.44 cm (range 0.81-1.79). The correlation coefficient for L1 and L1/2-L1 it was r = 0.82. Consequently, bone bridge between tunnels in patellas shorter than 3.46 cm, was less than 1 cm. R1 was 5.380 (range 3.2-9.5), R2 was 6.850 (range 3.8-10.7), and their difference reached statistical significance (p = 0.03).
Conclusion
Small-size patellae correlate with short maximum bone bridge between tunnels, which makes anatomic, double-bundle, hardware-free patella fixation, with two semi-patellar tunnels MPFL reconstruction challenging. Furthermore, R angles create a narrow window to avoid intraoperative breaching, rendering the use of the ACL tibia device an extremely useful instrument. This has clinical applications for any surgical technique utilizing patella bone tunnels, such as distal pole or sagittal patella fracture fixation