Manuel J Pellegrini1, Richard R Glisson2, Markus Wurm3, Paul H Ousema4, Michael M Romash5, James A Nunley6, Mark E Easley7. 1. Department of Orthopaedic Surgery, Hospital Clinico Universidad de Chile, Santiago, Chile mpellegrini@hcuch.cl. 2. Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina r.r.glisson@duke.edu. 3. Department of Orthopedic and Trauma Surgery, University Hospital Basel, Basel, Switzerland markus.wurm@usb.ch. 4. Department of Radiology, Deventer Ziekenhuis, Deventer, the Netherlands pousema@gmail.com. 5. Sports Medicine and Orthopaedic Surgery, Orthopedic Foot and Ankle Center of Hampton Roads, Chesapeake, Virginia orthofoot@cox.net. 6. Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina james.nunley@duke.edu. 7. Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina mark.e.easley@duke.edu.
Abstract
BACKGROUND: Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination. METHODS: Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios. RESULTS: Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed. CONCLUSIONS: Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible. CLINICAL RELEVANCE: If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures.
BACKGROUND: Distinguishing between ankle instability and subtalar joint instability is challenging because the contributions of the subtalar joint's soft-tissue constraints are poorly understood. This study quantified the effects on joint stability of systematic sectioning of these constraints followed by application of torsional and drawer loads simulating a manual clinical examination. METHODS: Subtalar joint motion in response to carefully controlled inversion, eversion, internal rotation, and external rotation moments and multidirectional drawer forces was quantified in fresh-frozen cadaver limbs. Sequential measurements were obtained under axial load approximating a non-weight-bearing clinical setting with the foot in neutral, 10° of dorsiflexion, and 10° and 20° of plantar flexion. The contributions of the components of the inferior extensor retinaculum were documented after incremental sectioning. The calcaneofibular, cervical, and interosseous talocalcaneal ligaments were then sectioned sequentially, in two different orders, to produce five different ligament-insufficiency scenarios. RESULTS: Incremental detachment of the components of the inferior extensor retinaculum had no effect on subtalar motion independent of foot position. Regardless of the subsequent ligament-sectioning order, significant motion increases relative to the intact condition occurred only after transection of the calcaneofibular ligament. Sectioning of this ligament produced increased inversion and external rotation, which was most evident with the foot dorsiflexed. CONCLUSIONS: Calcaneofibular ligament disruption results in increases in subtalar inversion and external rotation that might be detectable during a manual examination. Insufficiency of other subtalar joint constraints may result in motion increases that are too subtle to be perceptible. CLINICAL RELEVANCE: If calcaneofibular ligament insufficiency is established, its reconstruction or repair should receive priority over that of other ankle or subtalar periarticular soft-tissue structures.
Authors: Markus Regauer; Mirjam Lange; Kevin Soldan; Steffen Peyerl; Sebastian Baumbach; Wolfgang Böcker; Hans Polzer Journal: World J Orthop Date: 2017-03-18