Flattening of the talar dome is observed clinically in haemarthropathy as structural and functional changes advance but has not been quantified yet. In order to confirm clinical observation, and assess the degree of change, morphological measurements were derived from MR images. Four measurements were taken, using ImageJ (1.52v), from sagittal MRI projections at three locations – medial, lateral and central: Trochlear Tali Arc Length (TaAL), Talar Height (TaH), Trochlear Tali Length (TaL), and Trochlear Tali Radius (TaR). These measurements were used to generate three ratios of interest: TaR:TaAL, TaAL:TaL, and TaL:TaH. With the hypothesis of a flattening of the talar dome with haemarthropathy, it was expected that TaR:TaAL and TaL:TaH should be greater for haemophilic ankles, and TaAL:TaL should be smaller. A total of 126 MR images (ethics: MEEC 18–022) were included to assess the difference in those ratios between non-diseased ankles (33 images from 11 volunteers) and haemophilic ankles (93 images from 8 patients’ ankles). Non-diseased control measurements were compared to literature to assess the capacity of doing measurements on MRI instead of radiographs or CT.Abstract
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Flat-top talus (FTT) is a complication well-known to those treating clubfoot. Despite varying anecdotal opinions, its association with different treatments, especially the Ponseti method, remains uncertain. This systematic review aimed to establish the aetiology and prevalence of FTT, as well as detailing management strategies and their efficacy. A systematic review was conducted according to PRISMA guidelines to search for articles using MEDLINE, EMBASE and Web of Science until November 2021. Studies with original data relevant to one of three questions were included: 1) Possible aetiology 2) Prevalence following different treatments 3) Management strategies and their outcomes. 32 original studies were included, with a total of 1473 clubfeet. FTT may be a pre-existing feature of the pathoanatomy of some clubfeet as well as a sequela of treatment. It can be a radiological artefact due to positioning or other residual deformity. The Ponseti method is associated with a higher percentage of radiologically normal tali (57%) than both surgical methods (52%) and non-Ponseti casting (29%). Only one study was identified that reported outcomes after surgical treatment for FTT (anterior distal tibial hemiepiphysiodesis). The cause of FTT remains unclear. It is seen after all treatment methods but the rate is lowest following Ponseti casting. Guided growth may be an effective treatment. Key words: Clubfoot, Flat-top talus, Ponseti method, guided growth Disclosures: The authors have no relevant disclosures.
Open talus fracture are notoriously difficult to manage and they are commonly associated with a high level of complications including non-union, avascular necrosis and infection. Currently, the management of such injuries is based upon BOAST 4 guidelines although there is no suggested definitive management, thus definitive management is based upon surgeon preference. The key principles of open talus fracture management which do not vary between surgeons, however, there is much debate over whether the talus should be preserved or removed after open talus fracture/dislocation and proceeded to tibiocalcaneal fusion. A review of electronic hospital records for open talus fractures from 2014-2021 returned foureen patients with fifteen open talus fractures. Seven cases were initially managed with ORIF, five cases were definitively managed with FUSION, while the others were managed with alternative methods. We collected patient's age, gender, surgical complications, surgical risk factors and post-treatment functional ability and pain and compliance with BOAST guidelines. The average follow-up of the cohort was four years and one month. EQ-5D-5L and FAAM-ADL/Sports score was used as a patient reported outcome measure. Data was analysed using the software PRISM. Comparison between FUSION and ORIF groups showed no statistically significant difference in EQ-5D-5L score ( FUSION is typically used as second line to ORIF or failed ORIF. However, there are a lack of studies that directly compared outcome in open talus fracture patients definitively managed with FUSION or ORIF. Our results demonstrate for the first time, that FUSION may not be inferior to ORIF in terms of patient functional outcome, infection rate, and quality-of-life, in the management of patients with open talus fracture patients. Of note, as open talus fractures have increased risks of complications such as osteonecrosis and non-union, FUSION should be considered as a viable option to mitigate these potential complications in these patients.
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.
Primary bone tumours of the talus are rare. Currently the existing literature is limited to a single case series and case reports or cases described in series of foot tumours. Information regarding the patient's demographics and tumour types is therefore limited. The aim of this study was to investigate these questions and also suggest a management protocol for suspected primary bone tumours of the talus. We retrospectively reviewed the Scottish Bone Tumour Register from January 1954 to May 2010 and included all primary bone tumours of the talus. We identified only twenty three bone tumours over fifty six years highlighting the rarity of these tumours. There were twenty benign and three malignant tumours with a mean age of twenty eight years. A delay in presentation was common with a mean time from onset of symptoms to diagnosis of ten months. Tumour types identified were consistent with previous literature. We identified cases of desmoplastic fibroma and intraosseous lipodystrophy described for the first time. We suggest an investigatory and treatment protocol for patients with a suspected primary bone tumour of the talus. This is the largest series of primary bone tumours of the talus in the literature.
The arterial supply of the talus has been extensively studied in the past but there is a paucity of information on the arterial supply to the navicular and a very limited understanding of the intra-osseous supply to the surface of either of these bones. This is despite the likely importance of this supply in relation to conditions such as osteochondral lesions of the dome of the talus, and avascular necrosis and stress fracture of the navicular. Using cadaveric limbs, dissection of the source vessels was performed followed by arterial injection of latex. The talus and navicular were then removed en bloc, preserving the integrity of the injected arterial vasculature. The specimens were then processed using a new, accelerated diaphanisation technique. This rendered the tissue transparent, allowing the injected vessels to be visualised and then mapped onto a 3D virtual reconstruction of the bone. The vasculature to the subchondral surfaces of the talus and navicular, and the source vessel entry points that provide arterial supply into the navicular were identified. This study gives quantifiable evidence of the areas of consistently poor blood supply which may help explain the clinical pattern of talar and navicular pathology. It also provides as yet unpublished information on the arterial supply of the human navicular bone.
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
Abstract. Introduction. Ankle arthritis is estimated to affect approximately 72 million people worldwide. Treatment options include fusion and total ankle replacement (TAR). Clinical performance of TAR is not as successful as other joint replacement and failure is poorly understood. Finite element analysis offers a method to assess the strain in bone implanted with a TAR. Higher strain has been associated with microfracture and alters the bone-implant interface. The aim of this study was to explore the influence of implant fixation on strain within the tibia when implanted with a TAR through subject-specific models. Methods. Five cadaveric ankles were scanned using a Scanco Xtreme CT. The Tibia and
Abstract. Skeletal kinematics are traditionally measured by motion analysis methods such as optical motion capture (OMC). While easy to carry out and clinically relevant for certain applications, it is not suitable for analysing the ankle joint due to its anatomical complexity. A greater understanding of the function of healthy ankle joints could lead to an improvement in the success of ankle-replacement surgeries. Biplane video X-ray (BVX) is a technique that allows direct measurement of individual bones using highspeed, dynamic X-Rays. Objective. To develop a protocol to quantify in-vivo foot and ankle kinematics using a bespoke High-speed Dynamic Biplane X-ray system combined with OMC. Methods. Two healthy volunteers performed five level walks and step-down trials while simultaneous capturing BVX and synchronised OMC. participants undertook MR imaging (Magnetom 3T Prisma, Siemens) which was manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the
