The influence of size and comminution of the posterior malleolus fragment on gait in trimalleolar ankle fractures.

BACKGROUND: Ankle fractures involving the posterior malleolus generally lead to worse outcome. However, no studies on gait in trimalleolar ankle fractures have evaluated the influence of size and comminution of the posterior malleolar fragment. METHODS: We expected patients with more severely comminuted posterior malleolus, more severe fracture type and larger posterior fragment to have reduced gait kinematics and poorer patient-reported outcomes. 26 trimalleolar ankle fracture patients were compared with 14 healthy controls and kinematically analyzed using the Oxford Foot Model. Functional outcome was based on 4 patient reported outcome questionnaires. Effects of posterior fragment size, comminution and Haraguchi fracture classification were determined on conventional and 3D CT-scans. FINDINGS: Trimalleolar patients had lower walking speed and reduced range of motion between the hindfoot and tibia in both loading and push-off phases in the sagittal and transverse planes. The range between the hindfoot and tibia in the sagittal plane in the push-off phase correlated significantly with patient reported outcomes. The absolute and relative surface area of the posterior fragment on conventional CT-scans and 3D CT-scans, correlated significantly with range of motion. Patients with a posterior malleolus size >10% of the posterior malleolus had lower flexion-extension between forefoot and hindfoot during loading phase than patients with a size ≤10%. INTERPRETATION: Trimalleolar fractures reduce walking speed and range of motion in the talocrural joint. Reduced range in the talocrural joint is associated with poorer outcomes. Posterior fragment size correlated significantly with range of motion in talocrural and midfoot joints and with patient reported outcomes. LEVEL OF EVIDENCE: Level 3, retrospective study.

Gait analysis and functional outcome in patients after Lisfranc injury treatment.

INTRODUCTION: Lisfranc injuries involve any bony or ligamentous disruption of the tarsometatarsal joint. Outcome results after treatment are mainly evaluated using patient-reported outcome measures (PROM), physical examination and radiographic findings. Less is known about the kinematics during gait. METHODS: Nineteen patients (19 feet) treated for Lisfranc injury were recruited. Patients with conservative treatment and surgical treatment consisting of open reduction and internal fixation (ORIF) or primary arthrodesis were included. PROM, radiographic findings and gait analysis using the Oxford Foot Model (OFM) were analysed. Results were compared with twenty-one healthy subjects (31 feet). Multivariable logistic regression was used to determine factors influencing outcome. RESULTS: Patients treated for Lisfranc injury had a significantly lower walking speed than healthy subjects (P<0.001). There was a significant difference between the two groups regarding the range of motion (ROM) in the sagittal plane (flexion-extension) in the midfoot during the push-off phase (p<0.001). The ROM in the sagittal plane was significantly correlated with the AOFAS midfoot score (r2=0.56, p=0.012), FADI (r2=0.47, p=0.043) and the SF-36-physical impairment score (r2=0.60, p=0.007) but not with radiographic parameters for quality of reduction. In a multivariable analysis, the best explanatory factors were ROM in the sagittal plane during the push-off phase (ß=0.707, p=0.001), stability (ß=0.423, p=0.028) and BMI (ß=-0.727 p=<0.001). This prediction model explained 87% of patient satisfaction. CONCLUSIONS: This study showed that patients treated for Lisfranc injury had significantly lower walking speed and significantly lower flexion/extension in the midfoot than healthy subjects. The ROM in these patients was significantly correlated with PROM, but not with radiographic quality of reduction. Most important satisfaction predictors were BMI, ROM in the sagittal plane during the push-off phase and fracture stability.

Vertical ground reaction forces in patients after calcaneal trauma surgery.

INTRODUCTION: Vertical ground reaction forces (VGRFs) are altered in patients after foot trauma. It is not known if this correlates with ankle kinematics. The aim of this study was to analyze VGRFs in patients after calcaneal trauma and correlate them to patient-reported outcome measures (PROMs), radiographic findings and kinematic analysis, using a multi-segment foot model. In addition, we determined the predictive value of VGRFs to identify patients with altered foot kinematics. METHODS: Thirteen patients (13 feet) with displaced intra-articular calcaneal fractures, were included an average of two years after trauma surgery. PROMs, radiographic findings on postoperative computed tomography scans, gait analysis using the Oxford foot model and VGRFs were analysed during gait. Results were compared with those of 11 healthy subjects (20 feet). Speed was equal in both groups, with healthy subjects walking at self-selected slow speed (0.94±0.18m/s) and patients after surgery walking at self-selected normal speed (0.94±0.29m/s). ROC curves were used to determine the predictive value. RESULTS: Patients after calcaneal surgery showed a lower minimum force during midstance (p=0.004) and a lower maximum force during toe-off (p=0.011). This parameter correlated significantly with the range of motion in the sagittal plane during the push-off phase (r 0.523, p=0.002), as well as with PROMs and with postoperative residual step-off (r 0.423, p=0.016). Combining these two parameters yielded a cut-off value of 193% (p<0.001), area under the curve 0.93 (95%confidence interval 0.84-1.00). CONCLUSION: Patients after calcaneal fracture showed lower minimum force during midstance and lower maximum force during toe-off compared to healthy subjects. This lower maximum force during push-off correlated significantly with PROMs, range of motion in the sagittal plane during push-off and radiographic postoperative residual step-off in the posterior facet of the calcaneal bone. VGRFs are a valuable screening tool for identifying patients with altered gait patterns.