2015 ISAKOS Biennial Congress ePoster #1340

Kinematic Assessment of Landing After Hop of Patients with ACL Reconstruction at the Return to Sports Phase

Sofia A. Xergia, PhD, Nicosia CYPRUS
Evangelos Pappas, PT, PhD, OCS, Lidcombe, NSW AUSTRALIA
Mitsuo Ochi, MD, PhD, Higashi, Hiroshima JAPAN
Giuliano Giorgio Cerulli, MD, Perugia, PG ITALY
Anastasios D. Georgoulis, MD, Prof., Ioannina GREECE
Orthopaedic Sports Medicine Center of Ioannina, Department of Orthopaedic Surgery, University of Ioannina, Ioannina, Ioannina, GREECE

FDA Status Not Applicable

Summary: The results of the present study showed that patients after BPTB ACL reconstruction perform hopping tasks with reduced hip, knee and ankle flexion in the reconstructed lower extremity

Abstract:

STUDY DESIGN
Case Control

OBJECTIVES
To determine kinematic asymmetries in hop tests at the return to sports phase in anterior cruciate ligament reconstructed (ACLR) patients.

Background

There is a need to evaluate, in a homogenous sample, hop performance asymmetries of the three most commonly used hop tests in ACLR patients and the possible biomechanical mechanisms that may contribute to the asymmetries.

Methods

Twenty-two physically active men with ACLR after Bone Patellar Bone Tendon (BPTB) reconstruction participated (mean age ± SD, 28.8±11.2 yr, mean weight 76.75 ± 10.5 kg, mean height 1.77±0.04m), at 6-9 months after ACLR (mean time ± SD, 7.01± 0.93 months). All patients completed self-reported questionnaires (Lysholm, IKDC, Tegner Activity Level Score) and were evaluated in the functional tasks of the single, triple, and cross over hop tests. An eight-camera system (VICON, Oxford, UK) was used to capture (100 Hz) the coordinates of 16 reflective markers placed on selected bony landmarks of the lower limbs and the pelvis.
Peak flexion angles and peak flexion moments for the landing phases were calculated for the single hop and the final hop of the triple and crossover hops. Repeated measures MANOVAs were performed to investigate the differences between the intact and the reconstructed lower limb, followed by post-hoc univariate ANOVAs for comparisons that were statistically significant.

Results

The subjective assessments revealed that the ACLR patients had very good or excellent results (means±SD, IKDC 72.4± 8.8; Lysholm 93.4± 4.1; Tegner Activity Scale 5.1± 0.9). However, there were significant differences in joint angle flexion between the two lower limbs in the landing phase of the single (p=0.032), triple (p=0.002) and crossover hop (p=0.003). Subsequent univariate ANOVAs for the comparisons that showed statistical significance demonstrated that the reconstructed lower limbs compared to the intact lower limbs, consistently exhibited less peak knee (p=0.032) and ankle flexion (p=0.029) in the landing phase of all three hoping tasks, as well as less peak hip flexion (p=0.023) in the landing phase of the triple hop.

Conclusion

ACLR patients, 6-9 months after surgery demonstrate clear kinematic deficits during functional hop tests, although the Lysholm and IKDC scores are largely normal. The results showed that patients after BPTB ACL reconstruction perform hopping tasks with reduced hip, knee and ankle flexion in the reconstructed lower extremity. This may be a compensation mechanism indicative of knee flexion weakness and is associated with “hard landing” patterns that may increase landing forces. Therefore, clinicians should carefully evaluate landing patterns when deciding on return to sports for ACLR patients and incorporate exercises that facilitate knee flexion in those patients who exhibit a reduced flexion landing technique.
KEY WORDS
Anterior Cruciate Ligament Reconstruction, Hop tests, Knee.