The effect of extra-osseous talotarsal stabilization (EOTTS) to reduce medial knee compartment forces – An in vivo study

Abstract

BackgroundExcessive hindfoot pronation, talotarsal joint (TTJ) instability, has been attributed to an increase in medial knee compartment pathology. Advocacy for hindfoot realignment has been the subject of research. An internal solution for TTJ instability, extra-osseous talotarsal stabilization (EOTTS), exists but its effect on knee forces is unknown. This is the first study to measure the in vivo forces acting within the medial knee compartment before and after EOTTS. We hypothesized that following EOTTS there should be a reduction of force acting on the medial knee compartment.Methods10 fresh frozen cadaver lower extremities exhibiting clinical and radiographic evidence of TTJ instability were evaluated. The proximal femur segment was mounted to a mechanical testing unit. Pressure sensors were placed within the medial knee compartment. A force of 1000 newtons was then applied, and the femur was internally rotated 10 degrees. Measurements were recorded before and after the insertion of a type II EOTTS stent.ResultsPre-EOTTS resulted in an average of 842 ± 247N acting within the medial knee joint compartment. These forces then decreased to an average of 565 ± 260N (<0.05) following EOTTS, representing an average reduction of force by 32.8%.ConclusionEOTTS has been shown to decrease the in vivo forces action within the medial knee compartment. This helps to further illustrate the importance of realigning and stabilizing the hindfoot for the prevention and treatment of chronic knee pain.

Prospective, Long-Term Functional Outcomes of Extra-Osseous Talotarsal Stabilization (EOTTS) Using HyProCure in Adult Patients with Talotarsal Joint Instability: Assessment of Physical Activity and Patient Satisfaction

“…Kolodziej et al showed that EOTTS can reduce in vivo forces in the medial knee compartment. This helps illustrate the importance of rearfoot alignment and stabilization in preventing and treating chronic knee pain [10]. Rao et al indicated that an aberrant foot structure has been linked to foot osteoarthritis, as well as osteoarthritis and pain at the knee and hip [33].…”

“…), medial/lateral column osteotomy, and arthrodesis. EOTTS is associated with a reduced risk of post-operative complications and a shorter recovery time while maintaining the positive effects of treatment [2,10,[17][18][19][20]. Therefore, the main working hypothesis in our study was whether physically active patients were able to return to the same level of physical activity after TTJ instability surgeries.…”

“…TTJ instability affects the biomechanical alignment and functioning of the foot and the lower limb, and also the overall gait. It may also affect the proximal musculoskeletal joint alignments (knee, pelvis, and spine) [2,[7][8][9][10]. Tarsal pronation is correlated with internal rotation of the tibia and fibula that can cause internal rotational tension in the lower limb and thus lead to increased soft tissue loads and compression forces in other joints of the lower limb, which can result in pain and other associated symptoms.…”

“…Tarsal pronation is correlated with internal rotation of the tibia and fibula that can cause internal rotational tension in the lower limb and thus lead to increased soft tissue loads and compression forces in other joints of the lower limb, which can result in pain and other associated symptoms. Reports in the literature indicate a relationship between TTJ instability and pain symptoms in the knee [8][9][10][11][12], pelvis [7,8,13], spine [5,9], neck [9], shoulder [9], and even the temporomandibular joint [6,9]. The effects of hyperpronation on foot function have also been noted, including plantar fasciopathy, posterior tibial tendinopathy, hallux valgus, and metatarsal pain, all of which may manifest as foot pain [14,15].…”