ISAKOS: 2019 Congress in Cancun, Mexico

2019 ISAKOS Biennial Congress ePoster #1413


Comparison of Drop Landing Strategies between Patients with Deficient MPFL and Patients After MPFL Reconstruction

Efthymios Iliopoulos, MD, PhD, MBA, Thessaloniki GREECE
Michail I. Iosifidis, MD, PhD, Thessaloniki GREECE
Themis Tsatalas, MS, Trikala GREECE
Stefanos Kalolythos, MS, Trikala GREECE
Dimitrios Metaxiotis, MD, PhD, Thessaloniki GREECE
Dimitrios A. Patikas, PhD, Ag. Ioannis GREECE
Giannis Giakas, PhD, Trikala GREECE
Anastasios Mpeletsiotis, MD, PhD, Thessaloniki GREECE

OrthoBiology Surgery Center, Dept. of Physical Education & Sport Science, University of Thessaly, Papageorgiou General Hospital, School of Physical Education and Sport Science, Aristotle University of Thessaloniki, Thessaloniki, Trikala, GREECE

FDA Status Not Applicable


MPFL deficient patients guard their knee during demanding tasks such as drop landing. Despite the fact that there has been MPFL reconstruction, patients have still alter knee joint kinematics comparing to normal.



MPFL reconstruction has been a reliable and safe procedure for patients with recurrent patellar instability. Although previous studies did not reveal kinetic and kinematic alternations of these patients during gait, it is unclear if this is the case for more demanding tasks.

The aim of the present study was to investigate the drop landing strategies that these patients adopt pre and post operatively.

Study Design & Methods
Eight patients (aged 23.2 4.1 years) with confirmed MPFL symptomatic rupture formed the first study group and eight patients (aged 20 3.8 years) who were treated in our hospital with MPFL reconstruction 15.6 6 months after the procedure formed the second study group. A ten-camera motion analysis system and two force platforms were used to collect 3D data during bilateral drop landings from a 23cm box. Kinetic and kinematic data were collected from three trials. Data were averaged for each individual. A repeated measures analysis of variance was conducted to compare the lower limb biomechanics of the two groups. Statistical significance considered to be 0.05.


MPFL deficient patients have increased vertical ground reaction forces to the deficient limb comparing with their normal one (p=0.05) and they had increased maximum knee and ankle moments to their deficient limb (p= 0.05 and 0.04 respectively). Operated patients had similar vertical GRFs in both limbs. On the other hand, patients after MPFL reconstruction have increased maximum knee angle to the uninvolved limb and increased maximum knee moment compared to the operated one (p=0.05 and 0.009 respectively). This difference is not present to the deficient patients.


This study demonstrated that the MPFL deficient patients burden their injured limb during landing. Sixteen months after MPFL reconstruction the patients do not return to normal landing. They protect their operated limb by altering the kinematics of the uninvolved one

Keywords: Patella Instability, Recurrent Dislocation, Patellar, Kinetic, Kinematic