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.

Surgical treatment options for chronic instability of the peroneal tendons: a systematic review and proportional meta-analysis.

INTRODUCTION: Several surgical techniques for chronic instability of the peroneal tendons have been reported. Yet, the most optimal technique has not been clarified. This study aims to perform a systematic review and meta-analysis of all existing evidence and compare all published surgical techniques in both the athletic as the nonathletic population. MATERIALS AND METHODS: A systematic review and a proportional meta-analysis, with a random-effects model, were carried out according to the PRISMA guidelines, using the keywords "chronic luxation" OR "instability" AND "peroneal tendon" AND "treatment" OR "treatment protocol". Four surgical techniques were compared in patients with chronic peroneal instability, comprising superior peroneal retinaculum (SPR) repair or replacement, groove deepening procedures (primarily with additional SPR operations), rerouting procedures, and bony procedures (respectively group S, G, R and B). Outcomes of interest include the pre- and postoperative American orthopedic foot and ankle society hindfoot score, return to sports, postoperative redislocation and complications. Pooled estimates of the last two outcomes were obtained. RESULTS: For the systematic review, 31 studies were eligible. Of these, 25 papers met the criteria for inclusion in the meta-analysis. All techniques demonstrated a clinical improvement postoperatively. Group B, however, demonstrated overall more unsatisfactory results, and higher complication rates were observed for both group R and group B. The latter was established by the proportional meta-analysis as well [95% confidence interval group S: (0.01-0.10); group G: (0.02-0.10); group R: (0.13-0.57); group B: (0.24-0.40)]. Concerning surgical efficacy (= no postoperative redislocation), no significant difference was statistically observed. Finally, considerable differences in study quality were identified. CONCLUSION: Surgical treatment results in excellent clinical and functional outcomes in patients with chronic peroneal instability. More inferior results were demonstrated for rerouting and bony procedures. However, no high-quality studies are available and future randomized controlled trials are necessary to advocate for the most advantageous approach.

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.

Arthrodesis of the first metatarsophalangeal joint using an intraosseous fixation device.

The complication rate for an arthrodesis of the first metatarsophalangeal joint remains high. To improve results, we used a complete intraosseous fixation device (IOFIX) with proposed biomechanical advantages. Our hypothesis is that this technique has at least an equal union rate and less hardware irritation compared to other techniques. Seventy procedures were performed in 55 patients. Average follow-up was 24.5 months. All patients returned to follow-up after 6 weeks and were evaluated for union. Fifty-nine feet (84%) completed full follow- up. Union occurred in 62 of 70 feet (88.5%). Eight feet had nonunion at 1 year follow-up. Average time to fusion was 51 days. Three of 59 feet had malunion. No hardware removal was necessary. In conclusion, an MTP1 arthrodesis using IOFIX provides consistent and good functional outcomes. Due to the low-profile design, no hardware removal was necessary. However, union rates seem slightly lower compared to other techniques.

Posterior tibial tendon dysfunction alters the midfoot mechanics and energetics during gait.

A comprehensive insight into the in vivo foot kinetics of patients with posterior tibial tendon dysfunction (PTTD) is lacking to support clinical decision making. Our goal was to study how PTTD alters the kinetic and kinematic characteristics of the foot and ankle with a special focus on the midfoot joints. Multisegment foot joint kinetics and kinematics were compared based on the Rizzoli Foot Model and inversed dynamics between a control group (n = 25), patients with PTTD Stage II (n = 21) and PTTD Stage III (n = 4) over the entire stance phase. Compared to controls, a mean decrease in power generation of 1.3 W/kg was found in the Ankle joint in PTTD II patients (p < 0.001) and PTTD III patients of 1.5 W/kg (p < 0.001). In the Chopart joint, there was a mean increase in power absorption of 0.4 W/kg in the PTTD III patients (p = 0.014) and a mean decrease in power generation of 0.6 W/kg (p < 0.001) in the PTTD II patients. The distribution of total negative work showed a shift from the Ankle and first metatarsal phalangeal joint towards the Chopart joint in both PTTD compared with the control subjects. A significant reduction in range of motion was observed among both PTTD groups. The outcome of this study will enable the possibility to customize the conservative and surgical treatment of each patient with PTTD, to improve or even restore the kinetic features. This will prevent the natural deterioration of function seen in this pathology.

Reviving the debate: Articular cartilage preservation during disarticulation at the lower limb? A systematic review.

BACKGROUND: The need for preservation(P) or removal(R) of articular cartilage during disarticulations remains unanswered. METHODS: Medline database was used to conduct a systematic review regarding all types of minor disarticulations and some types of major disarticulations in patients with diabetes mellitus, peripheral arterial disease or trauma related disarticulations. Fisher-exact statistical test was used to perform calculations for the entire group as for subgroups. RESULTS: A total of 444 disarticulations at the Chopart joint, ankle and knee were included (P = 255 vs. R = 189). There was no difference in wound healing, functionality and mortality. Reamputation rate was lower in the P-group (9.4% vs. 16.9%). Infection rate was not significantly different. Differences in reamputations (R = 10.6% vs. P = 1.0%) and infections (R = 4.4% vs. P = 22.6%) were only present for the ankle subgroup. CONCLUSIONS: There is no difference in wound healing, functionality and mortality between the preservation and removal of articular cartilage in the lower limb.

Loss of Mechanical Ankle Function Is Not Compensated by the Distal Foot Joints in Patients with Ankle Osteoarthritis.

BACKGROUND: Patients with isolated ankle osteoarthritis (OA) often demonstrate disturbed ankle biomechanics during walking. Clinicians often believe that this triggers the distal foot joints to compensate these altered ankle biomechanics and that these foot joints are consequently subjected to degenerative joint diseases due to overuse. QUESTIONS/PURPOSES: Do patients with isolated ankle OA differ from those without ankle OA in terms of (1) ankle and foot joint kinematics and (2) ankle and foot joint kinetics as measured using three-dimensional (3-D) gait analysis? (3) Do these patients demonstrate compensatory strategies in their Chopart, Lisfranc, or first metatarsophalangeal joints in terms of increased joint kinematic and kinetic outputs? METHODS: Between 2015 and 2018, we treated 110 patients with unilateral ankle OA, and invited all of them to participate in the gait analysis laboratory. Of those, 47% (52) of patients did so, and of these, 16 patients met the inclusion criteria for this study, which were (1) diagnosis of unilateral ankle OA; (2) absence of radiographical signs of OA in the contralateral foot or lower limbs; (3) ability to walk at least 100 m without rest; and (4) being older than 18 years of age. A control group (n = 25) was recruited through intranet advertisements at the University Hospitals of Leuven. Participants were included if their age matched the age-range of the patient group and if they had no history of OA in any of the lower limb joints. Patients were slightly older (55.9 ± 11.2 years), with a slightly higher BMI (28 ± 6 kg/m2) than the control group participants (47.2 ± 4.4 years; p = 0.01 and 25 ± 3 kg/m2; p = 0.05). All participants underwent a 3-D gait analysis, during which a multisegment foot model was used to quantify the kinematic parameters (joint angles and ROM) and the kinetic parameters (rotational forces or moments), as well as power generation and absorption in the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during the stance phase of walking. Peak values were the maximum and minimum values of waveforms and the latter were time-normalized to 100% of the stance phase. RESULTS: Regarding joint kinematics, patients demonstrated a sagittal plane ankle, Chopart, Lisfranc, and first metatarsophalangeal joint ROM of 11.4 ± 3.1°, 9.7 ± 2.7°, 8.6 ± 2.3° and 34.6 ± 8.1°, respectively, compared with 18.0 ± 2.7° (p < 0.001), 13.9 ± 3.2° (p < 0.001), 7.1 ± 2.0° (p = 0.046) and 38.1 ± 6.5° (p = 0.15), respectively, in the control group during the stance phase of walking. With regard to joint kinetics in the patient group, we found a mean decrease of 1.3 W/kg (95% CI confidence interval 1.0 to 1.6) (control group mean: 2.4 ± 0.4 W/kg, patient group mean: 1.1 ± 0.5 W/kg) and 0.8 W/kg (95% CI 0.4 to 1.0) (control group mean: 1.5 ± 0.3 W/kg, patient group mean: 0.7 ± 0.5 W/kg) of ankle (p < 0.001) and Chopart (p < 0.001) joint peak power generation. No changes in kinetic parameters (joint moment or power) were observed in any of the distal foot joints. CONCLUSION: The findings of this study showed a decrease in ankle kinematics and kinetics of patients with isolated ankle OA during walking, whereas no change in kinematic or kinetic functions were observed in the distal foot joints, demonstrating that these do not compensate for the mechanical dysfunction of the ankle. CLINICAL RELEVANCE: The current findings suggest that future experimental laboratory studies should look at whether tibiotalar joint fusion or total ankle replacement influence the biomechanical functioning of these distal joints.

The Biomechanical Behavior of Distal Foot Joints in Patients with Isolated, End-Stage Tibiotalar Osteoarthritis Is Not Altered Following Tibiotalar Fusion.

Ankle arthrodesis is considered to be an optimal treatment strategy to relieve pain during walking in patients with isolated, end-stage tibiotalar osteoarthritis. The aim of this study was to investigate the post-operative effect of an arthrodesis on the ankle and foot joint biomechanics. We included both patients (n = 10) and healthy reference data (n = 17). A multi-segment foot model was used to measure the kinematics and kinetics of the ankle, Chopart, Lisfranc, and first metatarsophalangeal joints during a three-dimensional (3D) gait analysis. These data, together with patient reported outcome measures, were collected at baseline (pre-operative) and one year post-operatively. Patients experienced a decrease in pain and an increase in general well-being after surgery. Compared to the baseline measurements, patients only demonstrated a significant average post-operative increase of 0.22 W/kg of power absorption in the ankle joint. No other significant differences were observed between baseline and post-operative measurements. Current findings suggest that the biomechanical behavior of distal foot joints is not altered one year after fusion. The pain relief achieved by the arthrodesis improved the loading patterns during walking. Clinical significance of this study dictates that patients do not have to fear a loss in biomechanical functionality after an ankle arthrodesis.

Contribution of foot joints in the energetics of human running.

The foot seems to demonstrate considerable power absorption and generation characteristics during running. These have been mainly accounted to the mechanics of the ankle joint, however, evidence suggests that joint kinetics have been overestimated by single-segment foot models. The scope of the present study was to estimate the energetics of the ankle-, chopart-, lisfranc- and hallux joint during heel-strike running. Power absorption and generation occuring at different segments of the foot of seven asymptomatic adults was modelled using a four-segment kinetic foot model. Participants ran barefoot with an average running speed 3.5 m/s along a 10 meter walkway. The peak power generation of the ankle, chopart, lisfranc, and hallux joint reached respectively an average of 13.9, 4.12, 1.08 and 0.32 Watt/kg. The Lisfranc joint showed poor power absorption compared to the other three joints. It was further demonstrated that the Ankle and Chopart joints seem to have both receptive and propulsive characteristics. The behavior of the Lisfranc joint complied almost exclusively with propulsive characteristics. Finally, it can be concluded that the midfoot accounts for approximately 25% of the total power absorption occuring at the foot joints and not 50% as initially hypothesized.

The Receptive and Propulsive Behavior of Human Foot Joints During Running With Different Striking Strategies.

Foot structure and kinematics have long been considered as risk factors for foot and lower-limb running injuries. The authors aimed at investigating foot joint kinetics to unravel their receptive and propulsive characteristics while running barefoot, both with rearfoot and with midfoot striking strategies. Power absorption and generation occurring at different joints of the foot in 6 asymptomatic adults were calculated using both a 3-segment and a 4-segment kinetic model. An inverse dynamic approach was used to quantify mechanical power. Major power absorption and generation characteristics were observed at the ankle joint complex as well as at the Chopart joint in both the rearfoot and the midfoot striking strategies. The power at the Lisfranc joint, quantified by the 4-segment kinetic model, was predominantly generated in both strategies, and at the toes, it was absorbed. The overall results show a large variability in the receptive and propulsive characteristics among the analyzed joints in both striking strategies. The present study may provide novel insight for clinical decision making to address foot and lower-limb injuries and to guide athletes in the adoption of different striking strategies during running.

Quantifying clinical misinterpretations associated to one-segment kinetic foot modelling in both a healthy and patient population.

BACKGROUND: Rigid foot modelling approaches are still widely used to assess ankle joint kinetics in clinical biomechanical research. Yet, studies on healthy subjects using multi-segment kinetic foot models indicated that one-segment kinetic foot models tend to overestimate ankle joint kinetic data. Our aim was to compare ankle joint kinetics computed with a one-segment versus a multi-segment kinetic foot model in both asymptomatic and pathological gait. We also assessed whether differences between models can lead to different interpretations in clinical decision-making. METHODS: A two-factor repeated measure analysis of variance was performed to investigate differences in ankle joint kinetics, with the first factor being group effect (control vs. patients) and second factor being foot model effect (one-segment vs. multi-segment). Minimal detectable change was calculated to assess the clinical relevance of the observed differences in ankle joint kinetics. FINDINGS: Ankle joint peak kinematic, angular velocity and kinetic variables were all significantly overestimated (P < 0.05) when computed with the one-segment kinetic foot model. Kinetic differences in peak plantarflexion angular velocity and peak power generation were higher than their MDC-values. INTERPRETATION: Ankle joint kinetics are significantly overestimated when computed with a rigid foot modelling approach in both asymptomatic and pathological gait. This overestimation leads to clinical misinterpretations as MDC-values were less than the observed overestimation. In future studies, it is of clinical relevance to assess ankle joint kinetics with a multi-segment foot modelling approach.

Estimation of foot joint kinetics in three and four segment foot models using an existing proportionality scheme: Application in paediatric barefoot walking.

Recent studies which estimated foot segment kinetic patterns were found to have inconclusive data on one hand, and did not dissociate the kinetics of the chopart and lisfranc joint. The current study aimed therefore at reproducing independent, recently published three-segment foot kinetic data (Study 1) and in a second stage expand the estimation towards a four-segment model (Study 2). Concerning the reproducibility study, two recently published three segment foot models (Bruening et al., 2014; Saraswat et al., 2014) were reproduced and kinetic parameters were incorporated in order to calculate joint moments and powers of paediatric cohorts during gait. Ground reaction forces were measured with an integrated force/pressure plate measurement set-up and a recently published proportionality scheme was applied to determine subarea total ground reaction forces. Regarding Study 2, moments and powers were estimated with respect to the Instituto Ortopedico Rizzoli four-segment model. The proportionality scheme was expanded in this study and the impact of joint centre location on kinetic data was evaluated. Findings related to Study 1 showed in general good agreement with the kinetic data published by Bruening et al. (2014). Contrarily, the peak ankle, midfoot and hallux powers published by Saraswat et al. (2014) are disputed. Findings of Study 2 revealed that the chopart joint encompasses both power absorption and generation, whereas the Lisfranc joint mainly contributes to power generation. The results highlights the necessity for further studies in the field of foot kinetic models and provides a first estimation of the kinetic behaviour of the Lisfranc joint.

Foot segmental motion and coupling in stage II and III tibialis posterior tendon dysfunction.

BACKGROUND: Classification systems developed in the field of posterior tibialis tendon dysfunction omit to include dynamic measurements. Since this may negatively affect the selection of the most appropriate treatment modality, studies on foot kinematics are highly recommended. Previous research characterised the foot kinematics in patients with posterior tibialis tendon dysfunction. However, none of the studies analysed foot segmental motion synchrony during stance phase, nor compared the kinematic behaviour of the foot in presence of different posterior tibialis tendon dysfunction stages. Therefore, we aimed at comparing foot segmental motion and coupling in patients with posterior tibialis tendon dysfunction grade 2 and 3 to those of asymptomatic subjects. METHODS: Foot segmental motion of 11 patients suffering from posterior tibialis tendon dysfunction stage 2, 4 patients with posterior tibialis tendon dysfunction stage 3 and 15 asymptomatic subjects was objectively quantified with the Rizzoli foot model using an instrumented walkway and a 3D passive motion capture system. Dependent variables were the range of motion occurring at the different inter-segment angles during subphases of stance and swing phase as well as the cross-correlation coefficient between a number of segments. RESULTS: Significant differences in range of motion were predominantly found during the forefoot push off phase and swing phase. In general, both patient cohorts demonstrated a reduced range of motion compared to the control group. This hypomobility occurred predominantly in the rearfoot and midfoot (p<0.01). Significant differences between both posterior tibialis tendon dysfunction patient cohorts were not revealed. Cross-correlation coefficients highlighted a loss of joint coupling between rearfoot and tibia as well as between rearfoot and forefoot in both posterior tibialis tendon dysfunction groups. INTERPRETATION: The current evidence reveals considerable mechanical alterations in the foot which should be considered in the decision making process since it may help explaining the success and failure of certain conservative and surgical interventions.

Prediction of deformity in spinal tuberculosis.

Tuberculosis of the spine may cause kyphosis, which may in turn cause late paraplegia, respiratory compromise, and unsightly deformity. Surgical correction therefore may be considered for large or progressive deformities. We retrospectively analyzed clinical and radiographic parameters to predict the final kyphotic angle in spinal tuberculosis and to identify patients at risk of unfavorable outcomes at an early stage of the disease when surgery may be indicated. Unfavorable outcome was defined as progression of 10 degrees or greater and/or a final angle of 40 degrees or greater. We analyzed 53 patients with active spinal tuberculosis located in the thoracic (T1 to T10) and thoracolumbar spine (T11 to L2) and with initial kyphotic angles less than 40 degrees. We calculated the indexed total bone height loss, a value of 1 being the equivalent of the loss of a total vertebral body. There were no independent predictors. A bone height loss greater than 0.3 on the initial radiograph in combination with a thoracolumbar location indicated a 38% chance of unfavorable outcome versus only a 3% chance of unfavorable outcome when bone height loss was 0.3 or less in combination with a thoracic location. We present a simple and clinically useful algorithm for predicting kyphosis in spinal tuberculosis.