Foot biomechanics in patients with advanced subtalar- and mid-tarsal joint osteoarthritis and poorly responding to conservative treatment.

BACKGROUND: A comprehensive insight into the effects of subtalar- and mid-tarsal joint osteoarthritis on lower limb's biomechanical characteristics during walking is lacking. Our goal was to assess joint kinematics and kinetics and compensatory mechanisms in patients with subtalar and mid-tarsal joint osteoarthritis. METHODS: Patients with symptomatic and radiographically confirmed osteoarthritis of the subtalar and mid-tarsal (n = 10) and an asymptomatic control group (n = 10) were compared. Foot joint kinematics and kinetics during the stance phase of walking were quantified using a four-segment foot model. RESULTS: During pre-swing phase, the tibio-talar range of motion in the sagittal plane of the patient group decreased significantly (P = 0.001), whereas the tarso-metatarsal joint range of motion in the sagittal plane was greater in the pre-swing phase (P = 0.003). The mid-tarsal joint showed lower transverse plane range of motion in the patient group during the loading response and pre-swing phase (P < 0.001 resp. P = 0.002). The patient group showed a lower Tibio-talar joint peak plantarflexion moment (P = 0.004), peak plantarflexion velocity (P < 0.001) and peak power generation in the sagittal plane (P < 0.001), and a lower mid-tarsal joint peak adduction and abduction velocity (P < 0.001 resp. P < 0.001) and peak power absorption (P < 0.001). CONCLUSIONS: These findings suggest that patients with subtalar and mid-tarsal joint osteoarthritis adopt a cautious walking strategy potentially dictated by pain, muscle weakness, kinesiophobia and stiffness. Since this poorly responding population faces surgical intervention on the short term, we recommend careful follow-up after fusion surgery since biomechanical outcome measures associated to this post-surgical stage is lacking.

In Vivo Foot Segmental Motion and Coupling Analysis during Midterm Follow-Up after the Open Reduction Internal Fixation of Trimalleolar Fractures.

PURPOSE: Trimalleolar ankle fractures (TAFs) are common traumatic injuries. Studies have described postoperative clinical outcomes in relation to fracture morphology, but less is known about foot biomechanics, especially in patients treated for TAFs. The aim of this study was to analyze segmental foot mobility and joint coupling during the gait of patients after TAF treatment. METHODS: Fifteen patients, surgically treated for TAFs, were recruited. The affected side was compared to their non-affected side, as well as to a healthy control subject. The Rizzoli foot model was used to quantify inter-segment joint angles and joint coupling. The stance phase was observed and divided into sub-phases. Patient-reported outcome measures were evaluated. RESULTS: Patients treated for TAFs showed a reduced range of motion in the affected ankle during the loading response (3.8 ± 0.9) and pre-swing phase (12.7 ± 3.5) as compared to their non-affected sides (4.7 ± 1.1 and 16.1 ± 3.1) and the control subject. The dorsiflexion of the first metatarsophalangeal joint during the pre-swing phase was reduced (19.0 ± 6.5) when compared to the non-affected side (23.3 ± 8.7). The affected side's Chopart joint showed an increased range of motion during the mid-stance (1.3 ± 0.5 vs. 1.1 ± 0.6). Smaller joint coupling was observed on both the patient-affected and non-affected sides compared to the controls. CONCLUSION: This study indicates that the Chopart joint compensates for changes in the ankle segment after TAF osteosynthesis. Furthermore, reduced joint-coupling was observed. However, the minimal case numbers and study power limited the effect size of this study. Nevertheless, these new insights could help to elucidate foot biomechanics in these patients, adjusting rehabilitation programs, thereby lowering the risk of postoperative long-term complications.

Evidence for symmetrically reduced foot mechanics and energetics in patients after trimalleolar fracture repair: A cross-sectional study.

BACKGROUND: Trimalleolar fractures osteosynthesis is associated with a suboptimal outcome. It is hypothesized that patients with trimalleolar fractures face different ankle joint kinetics at mid- and long-term causing compensations at the distal foot joints. RESEARCH QUESTION: Do patients with a history of a trimalleolar fracture demonstrate different foot joint mechanics and energetics (1) between their affected side and their matched controls? (2) between their unaffected side and their matched controls? (3) between their affected side and their unaffected side? METHODS: Fifteen patients who sustained a trimalleolar fracture and underwent osteosynthesis for both the lateral, medial and posterior malleolus were compared to a asymptomatic control group which was matched for sex, age and walking speed. Three-dimensional gait analysis was used to quantify kinetic parameters in the Ankle, Chopart, Lisfranc and first metatarsophalangeal joint through a multi-segment kinetic foot model. Statistical analysis was performed using a Univariate Analysis of Covariance and/or a paired t-test. RESULTS: The peak internal ankle moment was significantly lower in patients when compared to the control group (p < 0.001). Mean peak power generation and total positive work were significantly lower for the Chopart joint when comparing the patients to the control group (p < 0.001). These results were observed for both the affected and unaffected side of the patients compared to the control group, showing symmetrical changes in the patient group. SIGNIFICANCE: Despite adequate radiographic quality of reduction and the fact that all patients were treated according to a fixed postoperative protocol, this study indicates that patients with a history of a trimalleolar fracture demonstrate reduced foot joint kinetics. It is hypothesized that these findings originate from extrinsic and intrinsic foot muscle strength, stiffness and pain. Future research is needed to validate this hypothesis.