Trochleoplasty improves knee flexion angles and quadriceps function during gait only if performed bilaterally

Abstract

Purpose To investigate if a trochleoplasty increases knee flexion angles and extensor moments in the gait of patients with patellar instability and to compare postoperative gait to a healthy control group. Methods A bilateral dislocation group (6 patients) and a unilateral dislocation group (14 patients) were treated with bilateral and unilateral trochleoplasty, respectively. Kinematics and kinetics of the lower extremity were captured using 3D‐gait analysis (VICON, 12 cameras, 200 Hz, plug‐in‐gait, two force plates). The mean of six trials was computed. The gait cycles were compared pre to postoperatively for each group. The gait of the two groups was compared to each other and the gait of a healthy population (54 knees). Results After trochleoplasty, the knee flexion angles and knee extensor moments only increased in the bilateral dislocation group, whereas the gait pattern of the unilateral dislocation group remained unchanged. Compared to the healthy population, the postoperative gait pattern of the bilateral dislocation group did not differ. In contrast, knee flexion angles and extensor moments of the unilateral dislocation group were still lower. Conclusion In adolescents with bilateral recurrent patellar dislocations, trochleoplasty of both knees increases knee flexion angles and knee extensor moments comparable to normal gait. Unilateral symptomatic patients undergoing a unilateral trochleoplasty did not achieve normal walking. These findings point out that patellar instability should be considered as a bilateral problem, even in patients with unilateral dislocations. Level of evidence III.

Gait Pathology in Subjects with Patellofemoral Instability: A Systematic Review

“…Almost all the studies [ 24 , 25 , 26 , 28 , 29 , 34 ] achieved a total score of 18 or higher out of a possible total of 22 points for the STROBE checklist. There is only one study by Sowiński et al [ 27 ] where nine of the 22 recommended points of the STROBE checklists were missing.…”

“…Two studies failed to report the specific demographic information of their participants [ 25 , 27 ]. Only two studies [ 28 , 34 ] reported how they derived their sample size. The results of the critical appraisal for each article are displayed in Table 3 .…”

“…The included studies were conducted in different parts of the world, including Poland [ 27 ], the USA [ 25 ], Austria [ 26 , 34 ], the UK [ 29 ], and Switzerland [ 24 , 28 ].…”

“…Of the seven included studies, one had a pre-post comparison design [ 28 ], two were assessed retrospectively [ 26 , 34 ], and four had a cross-sectional study design [ 24 , 25 , 27 , 29 ]. Only two studies reported spatio-temporal parameters [ 24 , 27 ], whereas all of the studies reported kinematic gait parameters [ 24 , 25 , 26 , 27 , 28 , 29 , 34 ]. Six studies also reported kinetic gait variables [ 24 , 25 , 26 , 28 , 29 , 34 ].…”

“…Several studies investigated the gait pattern in subjects with PI. These studies revealed that subjects with PI show, for instance, decreased gait velocity and cadence and greater internal knee abduction moment than healthy subjects [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. However, some of the studies reported inconsistent/contradictory results, which may indicate the existence of different compensatory gait strategies within subjects with PI due to the multiple influencing factors [ 29 ].…”