Advertisement for orthosearch.org.uk
Results 1 - 14 of 14
Results per page:
Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_11 | Pages 27 - 27
1 Jul 2014
Theelen L Wentink N Dhooge Y Senden R Hemert van W Grimm B
Full Access

Summary. Movement analysis (IMA) and activity monitoring (AM) using a body-fixed inertia-sensor can discriminate patients with ankle injuries from controls and between patients of different pathology or post-injury time. Weak correlations with PROMs show its added value in objectifying outcome assessment. Introduction. Ankle injuries often result in residual complaints calling for objective methods to score outcome alongside subjective patient-reported outcome measures (PROMs). Inertial motion analysis (IMA) and activity monitoring (AM) using a body-fixed sensor have shown clinical validity in patients suffering knee, hip and spine complaints. This study investigates the feasibility of IMA and AM 1) to differentiate patients suffering ankle injuries from healthy controls, 2) to compare different ankle injuries, 3) to monitor ankle patients during recovery. Methods. 32 patients suffering ankle problems (ankle sprain, n=17, 42 ±26yrs; operatively managed ankle fracture, n=15, 44 ±17yrs) during short-term recovery (6weeks to 3months post-trauma) were compared to 22 matched healthy controls (41 ±13yrs). Function was measured using IMA: Gait, Sit-Stand (STS) and 10s one-leg Balance test (OLB) were performed while wearing a 3D inertia-sensor at the lower back. Physical activity was measured during 4 successive days using a 3D accelerometer (AM), attached at the upper leg. Validated algorithms were used to derive motion parameters (e.g. speed for gait, bending angle for STS, sway area for OLB, # steps for AM). Moreover three ankle specific questionnaires were completed: Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ), Foot and Ankle Ability Measure (FAAM), AOFAS ankle-hindfoot score. Data was analysed using paired t-tests, one-way ANOVA and Pearson's r. Results. Both patient groups performed worse in function (IMA), activity (AM) and scales (PROM). Even at 3 months mean walking speed (−26%) and cadence (−9%) were slower while pelvic obliquity during ST (+18%) and sway during OLB (+230%) was higher than in controls (p<0.05). Activity was less regarding step/day (−31%) and sit-stand transfers (−11%, p<0.05). Also PROMs were significantly worse in patients (range 17–37%). Comparing in-between patients, significant differences were found in PROMs and function (IMA) with fracture patients walking slower (−30%) or showing more sway during one-legged balance (+250%). Mean activity scores (steps, bouts, cadence) were also less for fractures (p>0.05). During recovery, PROMs improved significantly, while function (IMA) and activity (AM) only showed small or selective improvements (e.g. 8° reduction in bending angle during ST, 20% increase in cadence). Only weak to moderate correlations were found between PROM, IMA (r-range: 0.32–0.79) and AM parameters (r-range: 0.31–0.71). Discussion & Conclusion. Function, physical activity and PROMs were impaired in patients with ankle injuries compared to healthy subjects, with the fracture group performing worse on IMA and PROMs than the sprain group. In this first study ever to measure activity in ankle patients, it was shown that e.g. fracture patients walk ca. half as many steps and bouts as age-matched controls even though at 6weeks they were unable to walk 20m without walking aids (floor effect of IMA function test). The lack of improvements in IMA and AM during recovery while PROMs improved significantly, together with the few and only weak-to-moderate correlations between PROMs, IMA and AM shows that subjective and objective recovery differ and highlight the added value of IMA and AM for objectifying routine clinical outcome assessment


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 37 - 37
1 Dec 2021
Chen H Gulati A Mangwani J Brockett C Pegg E
Full Access

Abstract

Objectives

The aim of this study was to develop an open-source finite element model of the ankle for identification of the best clinical treatment to restore stability to the ankle after injury.

Methods

The ankle geometry was defined from the Visible Human Project Female CT dataset available from the National Library of Medicine, and segmented using Dragonfly software (Object Research Systems, 2020). The finite element model was created with FEBio (University of Utah, 2021) using the dynamic nonlinear implicit solver. Linear isotropic material properties were assigned to the bones (E=7300MPa, ν=0.3, ρ=1730kg/m3) and cartilage (E=10MPa, ν=0.4, ρ=1100kg/m3). Spring elements were used to represent the ligaments and material properties were taken from Mondal et al. [1]. Lagrangian contact was defined between the cartilaginous surfaces with μ=0.003. A standing load case was modelled, assuming even distribution of load between the feet. A reaction force of 344.3N was applied to the base of the foot, a muscle force of 252.2N, and the proximal ends of the tibia and fibula were fully constrained.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_2 | Pages 70 - 70
2 Jan 2024
Peiffer M
Full Access

Acute syndesmotic ankle injuries continue to impose a diagnostic dilemma and it remains unclear whether weighbearing or external rotation should be exerted rotation during the imaging process. Therefore, we aimed to implement both axial load (weightbearing) and external rotation in the assessment of a clinical cohort of patients with syndesmotic ankle injuries syndesmotic using weightbearing CT imaging. In this retrospective comparative cohort study, patients with an acute syndesmotic ankle injury were analyzed using a WBCT (N= 20; Mean age= 31,64 years; SD= 14,07. Inclusion criteria were an MRI confirmed syndesmotic ankle injury imaged by a bilateral WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic ankle injuries. Three-dimensional (3D) models were generated from the CT slices. Tibiofibular displacement and Talar Rotation was quantified using automated3D measurements (Anterior TibioFibular Distance (ATFD), Alpha Angle, Posterior TibioFibular Distance (PTFD) and Talar Rotation (TR) Angle) in comparison to a cohort of non-injured ankles. Results. The difference in neutral-stressed Alpha° and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (P = 0.046 and P = 0.039, respectively) The difference in neutral-stressed PTFD and TR° did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (P = 0.492; P = 0.152, respectively). Conclusion. Application of combined weightbearing-external rotation reveals a dynamic anterior tibiofibular widening in patients with syndesmotic ankle injuries. This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. However, to what extent certain displacement patterns are associated with syndesmotic instability and thus require operative treatment strategies has yet to be determined in future studies


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 129 - 129
11 Apr 2023
Vermeir R Wittouck L Peiffer M Huysse W Martinelli N Stufkens S Audenaert E Burssens A
Full Access

The incisura fibularis (IF) provides intrinsic stability to the ankle joint complex by interlocking the distal tibia and fibula. Despite a high frequency of ligamentous ankle injuries, scant attention has been given to the morphology of the IF morphology incisura fibularis in the onset and development of these lesions. Therefore, we systematically reviewed the relation between ligamentous ankle disorders and the morphometrics of the IF. A systematic literature search was conducted on following databases: PubMed, Embase and Web of Science. Search terms consisted of ‘ankle trauma’, ‘ankle injury’, ‘ankle sprain’, ‘ankle fracture’, ‘tibiofibular’, ‘fibular notch’, ‘fibular incisura’, ‘incisura fibularis’, ‘morphometric analysis’, ‘ankle syndesmosis’, ‘syndesmotic stability’. The evaluation instrument developed by Hawker et al. was used to assess the quality of the selected studies. This protocol was performed according to the PRISMA guidelines and is registered on PROSPERO (CRD42021282862). Nineteen studies were included and consisted of prospective cohort (n=1), retrospective comparative (n=10), and observational (n=8) study design. Comparative studies have found certain morphological characteristics in patients with ankle instability. Several studies (n=5) have correlated a shallow IF depth with a higher incidence of ankle injury. A significant difference has also been found concerning the incisura height and angle (n=3): a shorter incisura and more obtuse angle have been noted in patients with ankle sprains. The mean Hawker score was 28 out of 36 (range=24-31). A shallower IF is associated with ligamentous ankle lesions and might be due to a lower osseous resistance against tibiofibular displacement. However, these results should be interpreted in light of moderate methodological quality and should always be correlated with clinical findings. Further prospective studies are needed to further assess the relation between the incisura morphometrics and ligamentous disorders of the ankle joint. Keywords: ankle instability, ankle injury, incisura fibularis, fibular notch, tibiofibular morphometrics, ankle syndesmosis


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_2 | Pages 5 - 5
2 Jan 2024
Huyghe M Peiffer M Cuigniez F Tampere T Ashkani-Esfahani S D'Hooghe P Audenaert E Burssens A
Full Access

One-fourth of all ankle trauma involve injury to the syndesmotic ankle complex, which may lead to syndesmotic instability and/or posttraumatic ankle osteoarthritis in the long term if left untreated. The diagnosis of these injuries still poses a deceitful challenge, as MRI scans lack physiologic weightbearing and plain weightbearing radiographs are subject to beam rotation and lack 3D information. Weightbearing cone-beam CT (WBCT) overcomes these challenges by imaging both ankles during bipedal stance, but ongoingdebate remains whether these should be taken under weightbearing conditions and/or during application of external rotation stress. The aim of this study is study therefore to compare both conditions in the assessment of syndesmotic ankle injuries using WBCT imaging combined with 3D measurement techniques. In this retrospective study, 21 patients with an acute ankle injury were analyzed using a WBCT. Patients with confirmed syndesmotic ligament injury on MRI were included, while fracture associated syndesmotic injuries were excluded. WBCT imaging was performed in weightbearing and combined weightbearing-external rotation. In the latter, the patient was asked to internally rotate the shin until pain (VAS>8/10) or a maximal range of motion was encountered. 3D models were developed from the CT slices, whereafter. The following 3D measurements were calculated using a custom-made Matlab® script; Anterior tibiofibular distance (AFTD), Alpha angle, posterior Tibiofibular distance (PFTD) and Talar rotation (TR) in comparison to the contralateral non-injured ankle. The difference in neutral-stressed Alpha angle and AFTD were significant between patients with a syndesmotic ankle lesion and contralateral control (P=0.046 and P=0.039, respectively). There was no significant difference in neutral-stressed PFTD and TR angle. Combined weightbearing-external rotation during CT scanning revealed an increased AFTD in patients with syndesmotic ligament injuries. Based on this study, application of external rotation during WBCT scans could enhance the diagnostic accuracy of subtle syndesmotic instability


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 43 - 43
1 Nov 2021
Peiffer M Arne B Sophie DM Thibault H Kris B Jan V Audenaert E
Full Access

Introduction and Objective. Forced external rotation is hypothesized as the key mechanism of syndesmotic ankle injuries. This complex trauma pattern ruptures the syndesmotic ligaments and induces a three-dimensional deviation from the normal distal tibiofibular joint configuration. However, current diagnostic imaging modalities are impeded by a two-dimensional assessment, without taking into account ligamentous stabilizers. Therefore, our aim is two-fold: (1) to construct an articulated statistical shape model of the normal ankle with inclusion of ligamentous morphometry and (2) to apply this model in the assessment of a clinical cohort of patients with syndesmotic ankle injuries. Materials and Methods. Three-dimensional models of the distal tibiofibular joint were analyzed in asymptomatic controls (N= 76; Mean age 63 +/− 19 years), patients with syndesmotic ankle injury (N = 13; Mean age 35 +/− 15 years), and their healthy contralateral equivalent (N = 13). Subsequently, the statistical shape model was generated after aligning all ankles based on the distal tibia. The position of the syndesmotic ligaments was predicted based on previously validated iterative shortest path calculation methodology. Evaluation of the model was described by means of accuracy, compactness and generalization. Canonical Correlation Analysis was performed to assess the influence of syndesmotic lesions on the distal tibiofibular joint congruency. Results. Our presented model contained an accuracy of 0.23 +/− 0.028 mm. Mean prediction accuracy of ligament insertions was 0.53 +/− 12 mm. A statistically significant difference in anterior syndesmotic distance was found between ankles with syndesmotic lesions and healthy controls (95% CI [0.32, 3.29], p = 0.017). There was a significant correlation between presence of syndesmotic injury and the morphological distal tibiofibular configuration (r = 0.873, p <0,001). Conclusions. In this study, we constructed a bony and ligamentous statistical model representing the distal tibiofibular joint Furthermore, the presented model was able to detect an elongation injury of the anterior inferior tibiofibular ligament after traumatic syndesmotic lesions in a clinical patient cohort


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_4 | Pages 104 - 104
1 Mar 2021
Segers T De Brucker D Huysse W Van Oevelen A Pfeiffer M Burssens A Audenaert E
Full Access

Syndesmotic ankle injuries are present in one fourth of all ankle trauma and may lead to chronic syndesmotic instability as well as posttraumatic ankle osteoarthritis. The main challenge remains distinguishing them from other types of ankle trauma. Currently, the patient's injured and non-injured ankles are compared using plain radiographs to determine pathology. However, these try to quantify 3D displacement using 2D measurements techniques and it is unknown to what extent the 3D configuration of the normal ankle syndesmosis is symmetrical. We aimed to assess the 3D symmetry of the normal ankle syndesmosis between the right and left side in a non- and weightbearing CT. In this retrospective comparative cohort study, patients with a bilateral non-weightbearing CT (NWBCT; N=28; Mean age=44, SD=17.4) and weight-bearing CT (WBCT; N=33; Mean age=48 years; SD=16.3) were analyzed. Consecutive patients were included between January 2016 and December 2018 when having a bilateral non-weightbearing or weightbearing CT of the foot and ankle. Exclusion criteria were the presence of hindfoot pathology and age less than 18 years or greather than 75 years. CT images were segmented to obtain 3D models. Computer Aided Design (CAD) operations were used to fit the left ankle on top of the right ankle. The outermost point of the apex of the lateral malleolus (AML), anterior tubercle (ATF) and posterior tubercle (PTF) were computed. The difference in the coordinates attached to these anatomical landmarks of the left distal fibula in the ankle syndesmosis with respect to right were used to quantify symmetry. A Cartesian coordinate system was defined based on the tibia to obtain the direction of differences in all six degrees of freedom. Statistical analysis was performed using the Mann-Whitney U test to allow comparison between measurements from a NWBCT and WBCT. Reference values were determined for each 3D measurement in a NWBCT and WBCT based on their 2SD. The highest difference in translation could be detected in the anterior-posterior direction (Mean AP. NWBCT. = −0.01mm; 2SD=3.43/Mean AP. WBCT. =−0.1mm; 2SD=2.3) and amongst rotations in the external direction (Mean AP. NWBCT. =−0.3°; 2SD=6.7/Mean AP. WBCT. =-0,2°; 2SD=5.2). None of these differences were statistically significant in the normal ankle syndesmosis when obtained from a NWBCT compared to a WBCT (P>0.05). This study provides references values concerning the 3D symmetry of the normal ankle syndesmosis in weightbearing and non-weightbearing CT-scans. These novel data contribute relevantly to previous 2D radiographic quantifications. In clinical practice they will aid in distinguishing if a patient with a syndesmotic ankle lesion differs from normal variance in syndesmotic ankle symmetry


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 98 - 98
11 Apr 2023
Williams D Chapman G Esquivel L Brockett C
Full Access

To be able to assess the biomechanical and functional effects of ankle injury and disease it is necessary to characterise healthy ankle kinematics. Due to the anatomical complexity of the ankle, it is difficult to accurately measure the Tibiotalar and Subtalar joint angles using traditional marker-based motion capture techniques. Biplane Video X-ray (BVX) is an imaging technique that allows direct measurement of individual bones using high-speed, dynamic X-rays. The objective is to develop an in-vivo protocol for the hindfoot looking at the tibiotalar and subtalar joint during different activities of living. A bespoke raised walkway was manufactured to position the foot and ankle inside the field of view of the BVX system. Three healthy volunteers performed three gait and step-down trials while capturing Biplane Video X-Ray (125Hz, 1.25ms, 80kVp and 160 mA) and underwent MR imaging (Magnetom 3T Prisma, Siemens) which were manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the Talus, Calcaneus and Tibia were calculated by manual matching of 3D Bone models to X-Rays (DSX Suite, C-Motion, Inc.). Kinematics were calculated using MATLAB (MathWorks, Inc. USA). Pilot results showed that for the subtalar joint there was greater range of motion (ROM) for Inversion and Dorsiflexion angles during stance phase of gait and reduced ROM for Internal Rotation compared with step down. For the tibiotalar joint, Gait had greater inversion and internal rotation ROM and reduced dorsiflexion ROM when compared with step down. The developed protocol successfully calculated the in-vivo kinematics of the tibiotalar and subtalar joints for different dynamic activities of daily living. These pilot results show the different kinematic profiles between two different activities of daily living. Future work will investigate translation kinematics of the two joints to fully characterise healthy kinematics


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_16 | Pages 63 - 63
1 Dec 2021
Ahmed R Ward A Thornhill E
Full Access

Abstract. Objectives. Ankle fractures have an incidence of around 90,000 per year in the United Kingdom. They affect younger patients following high energy trauma and, in the elderly, following low energy falls. Younger patients with pre-existing comorbidities including raised BMI or poor bone quality are also at risk of these injuries which impact the bony architecture of the joint and the soft tissues leading to a highly unstable fracture pattern, resulting in dislocation. At present, there is no literature exploring what effect ankle fracture-dislocations have on patients’ quality of life and activities of daily living, with only ankle fractures being explored. Methods. Relevant question formatting was utilised to generate a focused search. This was limited to studies specifically mentioning ankle injuries with a focus on ankle fracture-dislocations. The number of patients, fracture-dislocation type, length of follow up, prognostic factors, complications and outcome measures were recorded. Results. 939 fractures were included within the studies. Eight studies looked at previously validated foot and ankle scores, two primarily focused on the American Orthopaedic Foot and Ankle Society score (AOFAS), three on the Foot and Ankle Outcome Score (FAOS), and one study on the Olerud–Molander Score (OMAS). Patient, injury, and management factors were identified as being associated with poorer clinical outcomes. Conclusions. Not only are age and BMI a risk factor for posttraumatic osteoarthritis but they were also identified as prognostic indicators for functional outcome in this review. Patients sustaining a concurrent fracture-dislocation were found to have poorer clinical outcomes, and the timing and success of reduction further influenced outcomes. This review found that the quality of reduction was directly related to the patients’ functional outcomes post-follow up, and the risk of developing posttraumatic osteoarthritis, which was more frequent in patients sustaining Bosworth fractures, posterior malleolar fractures, and in patients over 35 years old


The ankle radiograph is a commonly requested investigation as the ankle joint is commonly injured. Each radiograph exposes 0.01 mSv of radiation to the patient that is equivalent to 1.5 days of natural background radiation [1]. The aim of the clinical audit was to use the Ottawa Ankle Rule to attempt to reduce the number of ankle radiographs taken in patients with acute ankle injuries and hence reduce the dose of ionising radiation the patient receives. A retrospective audit was undertaken. 123 ankle radiograph requests and radiographs taken between May and July 2018 were evaluated. Each ankle radiograph request including patient history and clinical examination was graded against the Ottawa Ankle Rule. The rule states that 1 point(s) indicates radiograph series; (1) malleolar and/or midfoot pain; (1) tenderness over the posterior 6cm or tip of the lateral or medial malleolus (ankle); (1) tenderness over the navicular or the base of the fifth metatarsal (foot); (1) unable to take four steps both immediately and in the emergency department [2]. Patients who score 0 do not need radiograph series. Each radiograph was reviewed if a fracture was present or not. The clinical audit identified 14 true positives where the Ottawa Ankle Rule scored 1 and the patient had an ankle fracture, and 2 false negatives (sensitivity 88%). There were 81 false positives, and 23 true negatives (specificity 22%). Therefore, a total of 23/123 ankle radiographs were unnecessary which is equivalent to 34.5 days of background radiation. The negative predictive value of the Ottawa Ankle Rule in this audit was 92%. The low rate of Ottawa rule utilisation may unnecessarily cause patient harm that should be addressed. An educational intervention with physicians combined with integration of the Ottawa rule scoring in ankle radiograph requests is planned with re-audit in 6 months


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 19 - 19
1 Dec 2020
Berry AL Scattergood SD Livingstone JA
Full Access

Diabetes has been associated with greater risk of complications and prolonged postoperative recovery following ankle trauma. Our cohort study reviewed the operative management and outcomes of ankle fractures in diabetic adults relative to non-diabetic adults from Jan 2016–2019. Non-diabetic controls were frequency age-matched 2:1. 34 of 572 ankle fracture presentations were in diabetic patients, 32% managed non-operatively compared to 29% of the matched non-diabetic cohort. The distribution in Lauge-Hansen fracture pattern was comparable between cohorts. Mean length of follow-up was significantly longer for diabetics (26 weeks) compared to non-diabetics (16 weeks). Post-operative wound complications (superficial wound infection, breakdown, dehiscence) occurred in 48% of the operated diabetic ankles, compared to 5% in non-diabetics (RR 8.1, 95% CI 2.5–26.4). Reoperation (RR 4.3, 95% CI 2.5–26.4, p=0.03) and non-wound complication rates (Charcot joint, mal/non-union, metalware infection) were likewise significantly higher (RR 3.9, 95% CI 1.4–10.8, p=0.008) in diabetics. Amongst diabetics alone, those with an HbA1c >69 mmol/mol (n=14, 41%) demonstrated a significantly higher rate still of non-wound complications (RR 4.3, 95% CI 1.1–18., p=0.03) with a trend towards higher wound complication rates (RR 3, 95% CI 0.52–17, p=0.13). Poorly controlled diabetes is associated with substantially greater complication rates following ankle fracture than those with well controlled or normal blood sugar; high HbA1c > 69mmol/mol is a significant predictor of complicated follow-up. Locally we recommend management strategies that are influenced by the fracture pattern stability and the presence or absence of complicated or poorly managed diabetes


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_2 | Pages 93 - 93
1 Mar 2021
Berry A Scattergood S Livingstone J
Full Access

Abstract. Objectives. Diabetes has been associated with greater risk of complications and prolonged postoperative recovery following ankle trauma. Our cohort study seeks to review the operative management and outcomes of ankle fractures in diabetic adults relative to non-diabetic adults. Methods. Cases were identified using ICD-10 coding criteria. 572 patients from Jan 2016–2019 presented with ankle fractures; 34 in diabetic patients. Mechanism of injury and stability were determined from the index radiograph using a validated Lauge-Hansen classification algorithm. Admission, primary post-operative and discharge radiographs were reviewed independently by two foot and ankle reconstruction specialists to assess adequacy of fixation method. 32% of diabetic patients were managed non-operatively compared to 29% of the matched non-diabetic cohort. The distribution in Lauge-Hansen fracture pattern was comparable between cohorts. Non-diabetic controls were frequency age-matched 2:1. Results. Mean length of follow-up was significantly longer for diabetics (26 weeks) compared to non-diabetics (16 weeks). Post-operative wound complications (superficial wound infection, breakdown, dehiscence) occurred in 48% of the operated diabetic ankles, compared to 5% in non-diabetics (RR 8.1, 95% CI 2.5–26.4). Reoperation (RR 4.3, 95% CI 2.5–26.4, p=0.03) and non-wound complication rates (Charcot joint, mal/non-union, metalwork infection) were likewise significantly higher (RR 3.9, 95% CI 1.4–10.8, p=0.008) in diabetics. Amongst diabetics alone, those with an HbA1c >69 mmol/mol (n=14, 41%) demonstrated a significantly higher rate still of non-wound complications (RR 4.3, 95% CI 1.1–18., p=0.03) with a trend towards higher wound complication rates (RR 3, 95% CI 0.52–17, p=0.13). Conclusions. Poorly controlled diabetes is associated with substantially greater complication rates following ankle fracture than those with well controlled or normal blood sugar; high HbA1c > 69mmol/mol is a significant predictor of complicated follow-up. Locally we recommend management strategies that are influenced by the fracture pattern stability and the presence or absence of complicated or poorly managed diabetes. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 61 - 61
1 Dec 2020
Ramos A Mesnard M Sampaio P
Full Access

Introduction. The ankle cartilage has an important function in walking movements, mainly in sports; for active young people, between 20 and 30 years old, the incidence of osteochondral lesions is more frequent. They are also more frequent in men, affecting around 21,000 patients per year in USA with 6.5% of ankle injuries generating osteochondral lesions. The lesion is a result of ankle sprain and is most frequently found in the medial location, in 53% of cases. The main objective of this work was to develop an experimental and finite element models to study the effect of the ankle osteochondral lesion on the cartilage behavior. Materials and Methods. The right ankle joint was reconstructed from an axial CT scan presenting an osteochondral lesion in the medial position with 8mm diameter in size. An experimental model was developed, to analyze the strains and influence of lesion size and location similar to the patient. The experimental model includes two cartilages constructed by Polyjet™ 3D printing from rubber material (young modulus similar to cartilage) and bone structures from a rigid polymer. The cartilage was instrumented with two rosettes in the medial and lateral regions, near the osteochondral region. The fluid considered was water at room temperature and the experimental test was run at 1mm/s. The Finite element model (FE) includes all the components considered in the experimental apparatus and was assigned the material properties of bone as isotropic and linear elastic materials; and the cartilage the same properties of rubber material. The fluid was simulated as hyper-elastic one with a Mooney-Rivlin behavior, with constants c1=0.07506 and c2=0.00834MPa. The load applied was 680N in three positions, 15º extension, neutral and 10º flexion. Results. The experimental strain measured in the cartilage in the rosettes presents similar behavior in all experiments and repetitions. The maximum value observed near the osteochondral lesion was 3014(±5.6)µε in comparison with the intact condition it was 468 (±1.95)µε. The osteochondral lesion increases the strains around 6.5 times and the synovial liquid reduces the intensity of strain distribution. The numerical model presents a good correlation with the experiments (R2 0.944), but the FE model underestimates the values. Discussion and conclusion. As a first conclusion, the size of the osteochondral lesion is important for the strains developed in cartilage. The size of lesion greater than 10mm is critical for the strains concentration. The synovial fluid present an important aspect in the strains measured, it reduces the strains in the external surface of cartilage and induces an increase in the lower part. This phenomenon should be addressed in more studies to evaluate this effect


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_16 | Pages 5 - 5
1 Nov 2018
Samaila E Negri S Magnan B
Full Access

Total ankle replacement (TAR) is contraindicated in patients with significant talar collapse due to AVN and in these patients total talus body prosthesis has been proposed to restore ankle joint. To date, five studies have reported implantation of a custom-made talar body in patients with severely damaged talus, showing the limit of short-term damage of tibial and calcaneal thalamic joint surfaces. Four of this kind of implants have been performed. The first two realized with “traditional” technology CAD-CAM has been performed in active patients affected by “missing talus” and now presents a survival follow-up of 15 and 17 years. For the third patient affected by massive talus AVN we designed a 3D printed porous titanium custom talar body prosthesis fixed on the calcaneum and coupled with a TAR, first acquiring high-resolution 3D CT images of the contralateral healthy talus that was “mirroring” obtaining the volume of fractured talus in order to provide the optimal fit. Then the 3D printed implant was manufactured. The fourth concern a TAR septic mobilization with high bone loss of the talus. The “two-stage” reconstruction conducted with the implant of total tibio-talo-calcaneal prosthesis “custom made” built with the same technology 3D, entirely in titanium and using the “trabecular metal” technology for the calcaneous interface. Weightbearing has progressively allowed after 6 weeks. No complications were observed. All the implants are still in place with an overall joint mobility ranging from 40° to 60°. This treatment requires high demanding technical skills and experience with TAR and foot and ankle trauma. The 15 years survival of 2 total talar prosthesis coupled to a TAR manufactured by a CAD-CAM procedure encourages consider this 3D printed custom implant as a new alternative solution for massive AVN and traumatic missing talus in active patients