Pathological Thresholds of Segmental Femoral Torsion in Patients With Patellar Dislocation: Influence on Patellofemoral Malalignment

Abstract

Background Femoral torsion can be evaluated from different femoral segments. The pathological thresholds for femoral torsion of different segments and the influence of segmental femoral torsion on patellofemoral alignment remain unknown. Purpose To compare femoral torsion between patients with recurrent patellar dislocation and healthy individuals, to determine the statistical physiological range and pathological thresholds of femoral torsion in different segments, and to investigate the influence of femoral torsion on patellofemoral malalignment. Study Design Cross-sectional study; Level of evidence, 3. Methods We retrospectively reviewed the records of patients with patellar dislocation who received surgical treatment in our department between 2019 and 2020. Healthy participants were recruited as the control group. The control patients were asymptomatic and had no history of lower extremity disorders. The differences in femoral torsion between the study and control groups were compared. The diagnostic capacity of femoral torsion in different segments and their correlation with patellar tilt were investigated. The mean value and 95% CI of femoral torsion in different segments were established using data from healthy volunteers. Results A total of 60 patients with patellar dislocation and 100 healthy volunteers were included in this study. The total, mid, and distal femoral torsion values differed significantly between the study and control groups ( P < .01). Total femoral torsion had the highest diagnostic value (area under the receiver operating curve = 0.733). Total torsion ( r = 0.432; P < .001), mid torsion ( r = 0.242; P = .002), and distal torsion ( r = 0.324; P < .001) showed significant correlations with patellar tilt. The pathological thresholds of excessive femoral torsion of the total, proximal, mid, and distal femoral segments were 24.73°, 46.68°, –6.55°, and 14.92°, respectively. Conclusion Patients with patellar dislocation had greater femoral torsion than healthy individuals in multiple femoral segments. Excessive mid, distal, and total torsion was associated with more significant patellar tilt.

Clinical outcomes of derotational femoral osteotomy combined with medial patellofemoral ligament reconstruction in patients with patellar dislocation and increased femoral anteversion unaffected by the pattern of distribution of femoral torsion

“…However, our follow‐up results show that derotational femoral osteotomy still demonstrates good postoperative results for patients in the distal torsion group. Xu et al reported that excessive shaft, distal and total torsion of the femur were associated with more significant patellar tilt [23]. On the one hand, there was a significant increase in supracondylar torsion in this group of patients compared with patients with normal FA, and derotational femoral osteotomy reduced the risk of redislocation by decreasing the lateral sagittal tension in the patients.…”

“…Seitlinger et al and Xu et al reported that high femoral torsion consists of pronation of the femoral neck, external rotation of the femoral shaft and internal rotation of the distal end of the femur [9, 23]. Qiao et al also found that in patients with patellar dislocations, the site of increased FA of the femur is located predominantly at the shaft and distal end of the femur [28].…”

“…Seitlinger et al reported that the femoral neck and femoral shaft maintained a high correlation [9], demonstrating that femoral neck and femoral shaft torsion were integrated manifestations. Several authors have also previously reported that the most influential components for femoral torsion are the femoral shaft and the distal femur [9][10][11]23], so we defined simultaneous measurement of femoral neck and femoral shaft torsion as supracondylar femoral torsion, highlighting the importance of distal femoral torsion.…”

Management of the first episode of traumatic patellar dislocation: an international survey

“…Given the high rate of recurrence, tissue damage, and poor functional outcome, patellar dislocation for the first time causes significant morbidity and might represent a reason for sport retirement [6, 19, 27]. The recurrence rate following conservative management is approximately 25%; therefore, receiving proper treatment after the first episode of patellar dislocation has a considerable impact on the outcome [7, 20, 22, 24].…”

“…Second, in conservatively treated patients, most surgeons recommended weight-bearing to tolerance and a knee brace during the irst four weeks, with a range of motion of 30° during the irst 15 days and up to 60° for an additional 15 days (Fig. Third, surgical Given the high rate of recurrence, tissue damage, and poor functional outcome, patellar dislocation for the irst time causes signiicant morbidity and might represent a reason for sport retirement [6,19,27]. The recurrence rate following conservative management is approximately 25%; therefore, receiving proper treatment after the irst episode of patellar dislocation has a considerable impact on the outcome [7,20,22,24].…”