Is Gait Analysis for Proposed Rotational Deformities a Useful Resource

Patellofemoral pain (PFP) is one of the most common disorders in orthopaedic clinics (Rothermich, 2015). The knee pain is said to responsible for 25-40% of annual incidence, though a true prevalence is unknown (Witvrouw, 2014)(Lankhortst et al, 2012). Patient demographics range from young, active individuals to sedentary, elderly individuals (Witvrouw, 2014). Primary care consultations to orthopaedic and musculoskeletal clinics, from knee pain alone, are reported to account for over 100,000 appointments annually (Smith et al., 2018). This costs the UK economy around £7.4million a year through employment absenteeism, alongside additional costs for non-operative and operative treatment procedures (Smith et al., 2018)(Swan et al., 2010). Alongside age and activity, an important variable in understanding the epidemiology of PFP is the difference in the incidence and prevalence between genders. Many epidemiologic studies have shown that females have a two-fold higher incidence rate of the disorder than males (Rothermich, 2015). The aetiology of PFP is evasive and multifactorial. Therefore, patients presenting with this syndrome pose a challenge for the diagnosis and long-term treatment of the pain. An important part of the diagnosis for the disorder is to rule out any other possible causes such as plica syndrome, neuromas or intra-articular pathology (Rothermich, 2015). Combinations of malalignment of the lower extremities, imbalance in muscles of the hips and knee joints, and over use, are the main factors which present most often and are considered causative to the disorder (Rothermich, 2015). One main contributors to PFP is that of lower limb structural factors, such as femoral ante/retro version and tibial torsion (Snow, 2021). These factors are thought to significantly effect gait and muscular function, which results in overloading of the joint and disturbed patellofemoral mechanics (Snow, 2021). Currently, computerised tomography (CT) is the gold standard tool used to quantify rotational deformity on the lower limb (Snow, 2021). However, CT is a static imaging modality and does not capture the 'real life' dynamic kinetics that occur through movement (Saevarsson et al., 2013). Gait analysis provides important quantitative information of the biomechanical parameters undertaken in the knee joint during dynamic movement. In patients with rotational deformities, these parameters are either heightened or decreased on activity (Arazpour et al., 2016). Therefore, it is questioned as to whether gait analysis can detect a rotational deformity in the lower limb and determine whether the changes seen are proportionate to the level of deformity. Consequently, questioning as to whether gait analysis is an appropriate tool for diagnostic and treatment pathways for PFP.