Do the quadriceps and hamstring muscles have an effect on patella stability in trochlear dysplasia?

Abstract

Introduction Trochlear dysplasia (TD) is a condition that is characterized by the presence of either a flat or convex trochlear, which impedes the stability of the patellofemoral joint (PFJ). The PFJ function is dependent on many different structures that surround the knee joint. The aim of this study was to analyse all the muscle components around the PFJ and identify whether gross muscle imbalance could contribute to the stability of the patella in TD. Material and methods The average cross-sectional area (CSA) and cross-sectional area ratio (CSAR) of each muscle of the thigh region in subtypes of TD was evaluated and compared to normal knee joints. Ninety-eight patients (196 knees in total) were included in the study. Results Of the 196 knee joints that were reviewed, 10 cases were found to be normal. In total, 186 cases were positive for TD. The majority consisted of type C. The hamstring muscles showed variable results. The vastus medialis muscle was larger in comparison to the vastus lateralis muscle over all the different TD subtypes; however, no statistical significance was identified. There was a marked statistical significance between the quadriceps and hamstring muscles, especially when comparing this to the normal knees within our cohort. Conclusions This study revealed no significant difference in the effect of the thigh muscle CSA on the stability of the PFJ in TD. Further research is required to establish the roles of the different muscles around PFJ in the prevention of TD dislocation.

Quadriceps Muscle and Medial Retinaculum Combinate Effects on Patellar Instability during Knee Flexion

“…These muscle synergies are also supported by numerous studies showing the negative effect of imbalanced forces after vastus lateralis tendon release surgery alone [67], or medial plication [68], demonstrating that a whole-joint procedure is the best solution [69,70]. As a result, these data support both preventive and post-operative rehabilitation for patellar instability using both clinical assessment and radiological parameters [66].…”

“…Many studies have investigated the role of the quadriceps in patellar stabilisation and dislocation, suggesting that a balance between the forces of the individual muscle components is necessary for patellar stability. In particular, the vastus obliquus medialis fascia plays a crucial role during flexion-extension movements, assisted by the medial and lateral retinaculum [64][65][66].…”

Alteration of patellar tendon morphology in patellofemoral instability (trochlear dysplasia)

“…Role of dynamic factors such as the quadriceps and hamstrings in PFJ instability associated with TD has been investigated. 14,19 Hypertrophy of VM and VL has been noted throughout the different subtypes of TD (average CSA ratio of 2.3 to 1) suggesting these muscles to be vital factors in offsetting natural tendency of lateral patellar dislocation in such patients. 14 In this study, we have tried to analyse the role of the other dynamic factor around the knee joint i.e.…”

“…14,19 Hypertrophy of VM and VL has been noted throughout the different subtypes of TD (average CSA ratio of 2.3 to 1) suggesting these muscles to be vital factors in offsetting natural tendency of lateral patellar dislocation in such patients. 14 In this study, we have tried to analyse the role of the other dynamic factor around the knee joint i.e. patellar tendon in patients with PFJ instability and TD.…”

“…Saad et al have explored the role of quadriceps and hamstring muscle components on patellar instability in TD. 14 The authors found consistent hypertrophy of VM and vastus lateralis (VL) in different subtypes of TD. They believe restoration of balance between VM and VL is critical in offsetting lateral PFJ dislocation.…”