Recurrent patellar dislocations in adolescents result in decreased knee flexion during the entire gait cycle

Knee Surg Sports Traumatol Arthrosc. 2020 Jul;28(7):2053-2066. doi: 10.1007/s00167-020-05911-y. Epub 2020 Mar 4.


Purpose: To evaluate the kinematics/kinetics of the ankle, knee, hip in the sagittal plane in adolescents with recurrent patellar dislocation in comparison to a healthy control.

Methods: Case-control study. Eighty-eight knees (67 patients) with recurrent patellar dislocation (mean age 14.8 years ± 2.8 SD) were compared to 54 healthy knees (27 individuals, 14.9 years ± 2.4 SD). Kinematics/kinetics of ankle, knee, hip, and pelvis were captured using 3D-gait analysis (VICON, 12 cameras, 200 Hz, Plug-in-Gait, two force plates). One cycle (100%) consisted of 51 data-points. The mean of six trials was computed.

Results: The loading-response increased by 0.02 s ± 0.01SE (10.8%) with dislocations (0.98% of total gait, P < 0.01). The mid-stance-phase decreased equally (P < 0.01). Dislocation decreased knee flexion during the entire gait cycle (P < 0.01), with the largest difference during mid-stance (9.0° ± 7.2 SD vs. 18.5° ± 6.7 SD). Dislocation increased plantar-flexion during loading response 4.1° ± 0.4 SE with (P < 0.01), afterward, the dorsal-extension decreased 3.2° ± 0.3 SE, (P < 0.01). Dislocation decreased hip flexion during all phases (P < 0.01). Maximal difference: 7.5° ± 0.5 SE during mid-stance. 80% of all patients developed this gait pattern. Internal moments of the ankle increased, of the knee and hip decreased during the first part of stance.

Conclusion: Recurrent patellar dislocation decreases knee flexion during the loading-response and mid-stance phase. A decreased hip flexion and increased plantar-flexion, while adjusting internal moments, indicate a compensation mechanism.

Level of evidence: III.

Keywords: Adolescents; Gait analysis; Kinematics; Kinetics; Knee; Patella dislocation; Patellar dislocation; Quadriceps avoidance; Recurrent dislocation; Trochlear dysplasia.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Biomechanical Phenomena / physiology
  • Case-Control Studies
  • Female
  • Gait Analysis* / methods
  • Humans
  • Knee Joint / physiopathology*
  • Lower Extremity / physiology
  • Male
  • Patellar Dislocation / physiopathology*
  • Range of Motion, Articular / physiology*
  • Recurrence