The effect of rotational deformity on patellofemoral parameters following the treatment of femoral shaft fracture

Abstract

The results of this study revealed that more than 10° of external rotation deformity could cause a detoriation in the patellofemoral scores. Anatomic reduction of the fracture site should be performed as soon as possible and external rotational deformities should especially be avoided in order to prevent patellofemoral malalignment.

Femoral malrotation from diaphyseal fractures results in changes in patellofemoral alignment and higher patellofemoral stress from a finite element model study

“…We reported that femur malrotation > 10° was associated to an increase in patellar tilt and congruence angle. Yildirim et al reported the effect of femoral deformity following femoral shaft fracture, underlying the role of external malrotation > 10° [6]. They observed deterioration in the PF scores and medial patellar tilt for patient with such deformities.…”

“…PF changes in axial alignment are clinically relevant, especially for anterior knee pain and patellar instability [4,6,12]. However, the influence of stress distribution in anterior pain is controversial, because of the participation of the involved biological factors.…”

“…Yildirim et al reported a decrease in the mean patella score due to external malrotation beyond 10° [6]. External rotation appeared to be more tolerate than internal rotation, especially because of foot compensation and ability to correct limb rotational alignment [2].…”

“…Fracture of the femoral shaft is classically managed by antegrade intramedullary nailing as the standard treatment. Good results are reported due to early weight-bearing conditions and joint physiotherapy [1][2][3][4][5][6]. However femoral malrotation of more than ten degrees ranges until 40% in clinical series [2,5].…”

Rotational malalignment after closed intramedullary nailing of femoral shaft fractures and its influence on functional outcome

“…9 Yildirim et al stated that patellofemoral malalignment following closed IMN could cause pain and decreased patellofemoral scores. 28 Ozgur consistently found patients with rotational malalignment complaining of anterior knee pain while climbing stairs and attributed it to imbalance of the patellofemoral mediolateral force secondary to a torsional deformity of the femur. 29,30 In our study no significant difference was noted between the groups in terms of HHS probably because of the limited number of cases, short duration of follow up and absence of extreme rotational malalignment >20 0 .…”