Sander Wuite

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.

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.

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.

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.