Introduction. Treatment pathways of 5. th. metatarsal fractures are commonly directed based on fracture classification, with Jones types for example, requiring closer observation and possibly more aggressive management. Primary objective. To investigate the reliability of assessment of subtypes of 5. th. metatarsal fractures by different observers. Methods. Patients were identified from our prospectively collected database. We included all patient referred to our virtual fracture clinic with a suspected or confirmed 5. th. metatarsal fracture. Plain AP radiographs were reviewed by two observers, who were initially trained on the 5. th. metatarsal classification identification. Zones were defined as Zone 1.1, 1.2, 1.3, 2, 3, diaphyseal shaft (DS), distal metaphysis (DM) and head. An inter-observer reliability analysis using Cohen's Kappa coefficient was carried out, and degree of observer agreement described using Landis & Koch's description. All data was analysed using IBM SPSS v.27. Results. 878 patients were identified. The two observers had moderate agreement when identifying fractures in all zones, apart from metatarsal head fractures, which scored substantial agreement (K=.614). Zones 1.1 (K=.582), 2 (K=.536), 3 (K=.601) and DS (K=.544) all tended towards but did not achieve substantial agreement. Whilst DS fractures achieved moderate agreement, there was an apparent difficulty with distal DS, resulting in a lot of cross over with DM (DS 210 vs 109; DM 76 vs 161). Slight agreement with the next highest adjacent zone was found when injuries were thought to be in zones 1.2, 1.3 and 2 (K=0.17, 0.115 and 0.152 respectively). Conclusions. Reliability of sub-categorising 5. th. metatarsal fractures using standardised instructions conveys moderate to substantial agreement in most cases. If the region of the fracture is going to be used in an algorithm to guide a management plan and clinical follow up during a virtual clinic review, defining fractures of zones 1–3 needs careful consideration

Background. The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to classify the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods. We included 20 cavovarus feet from adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, 14 males). Patients included had flexible deformities, with no previous surgery. Previous work established majority of rotational deformity in cavovarus feet occurs at the talonavicular joint, which is often reduced during surgery. Using specialised software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using data from normal feet as a guide, the talonavicular joint of the cavovarus feet was digitally reduced to a ‘normal’ position. Models of the corrected position were exported and geometrically analysed using Blender 3.6 to identify anatomical trends. Results. We identified 3 types of cavovarus forefoot morphotypes. Type 1 was seen in 13 cases (65%) and was defined as a foot where only the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular correction. Type 2 was seen in 4 cases (20%) and was defined as a foot where the second and first metatarsals were progressively plantarflexed, with no significant adduction. Type 3 was seen in 3 cases (15%) and was defined as a foot where the metatarsals were still adducted after talonavicular de-rotation. Conclusion. We classify 3 forefoot morphotypes in cavovarus feet. It is important to recognise and anticipate the residual forefoot deformities after hindfoot correction as different treatment strategies may be required for different morphotypes to achieve balanced correction

Isolated talonavicular arthrodesis is a common procedure particularly for posttraumatic arthritis and rheumatoid arthritis. Two surgical approaches are commonly used: the medial approach and the dorsal approach. It is recognized that access to the lateral aspect of the talonavicular joint can be limited when using the medial approach and it is our experience that using the dorsal approach addresses this issue. We performed an anatomical study using cadaver specimens, to compare the amount of articular surface that can be accessed, and therefore prepared for arthodesis, by each surgical approach. Medial and dorsal approaches to the talonavicular joint were performed on each of 10 cadaveric specimens. Distraction of the joint was performed as standard for preparation of articular surfaces during talonavicular arthrodesis. The accessible area of articular surface was marked for each of the two approaches. Disarticulation was performed and the marked surface area was quantified using a digital Microscribe allowing a three dimensional virtual model of the articular surfaces to be assessed. This study will provide quantifiable measurements of the articular surface accessible by the medial and dorsal approaches to the talonavicular joint. These data may provide support for the use of the dorsal approach for talonavicular arthrodesis

The arterial supply of the talus has been studied extensively in the past. These have been used to improve the understanding of the risk of avascular necrosis in traumatic injuries of the talus. There is, however, poor understanding of the intra-osseous arterial supply of the talus, important in scenarios such as osteochondral lesions of the dome. Previous studies have identified primary sources of arterial supply into the bone, but have not defined distribution of these sources to the subchondral regions. This study aims to map the arterial supply to the surface of the talus. Cadaveric limbs (n=10) were dissected to identify source vessels for each talus. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each talus was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined. This study will provide quantifiable evidence of areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. These data may help to explain the distribution and mechanisms behind the development of the subchondral cysts of the talus

Introduction. The anatomy of the first metatarsophalangeal (MTP) joint and, in particular, the metatarsosesamoid articulation remains poorly understood. The movements of the sesamoids in relation to the metatarsal plays a key role in the function of the first MTP joint. Although the disorders affecting the sesamoids are described well, the movements of the metatarsosesamoid joints and the pathomechanics of these joints have not been described. We have performed a cadaver study detailing and quantifying the three dimensional movements occurring at these joints. Methods. Fresh frozen cadaveric specimens without evidence of forefoot deformity were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in positions ranging from 10 degrees of dorsiflexion to 60 degrees of plantarflexion using a MicroScribe, enabling quantitative analyses in a virtual 3D environment. Results. The sesamoids demonstrated excursion both in the sagittal and coronal plane. The tibial sesamoid had a mean saggital excursion of 14.2 mm; the mean excursion of the fibular sesamoid was 8.7 mm. The mean coronal excursion of the tibial sesamoid was 2.8 mm while that of the fibular sesamoid was 3.2 mm. We also describe the mean saggital and coronal excursion of the sesamoids during smaller, incremental motions of the MTP joint. Conclusion. There appears to be differential tracking of the hallucal sesamoids. The tibial sesamoid has comparatively increased longitudinal excursion whilst the fibular sesamoid has comparatively greater lateral excursion. Clinical relevance. The greater excursion of the tibial sesamoid could explain the higher incidence of pathology in this bone. The differential excursion of the sesamoids is also a factor that should be considered in the design and mechanics of an effective hallux MTP joint arthroplasty

There is a paucity of information on the arterial supply of the navicular, despite its anatomic neighbours, particularly the talus, being investigated extensively. The navicular is essential in maintaining the structural integrity of the medial and intermediate columns of the foot, and is known to be at risk of avascular necrosis. Despite this, there is poor understanding of the vascular supply available to the navicular, and of how this supply is distributed to the various surfaces of the bone. This study aims to identify the key vessels that supply the navicular, and to map the arterial supply to each surface of the bone. Cadaveric limbs (n=10) were dissected to identify source vessels for each navicular. The talus and navicular were removed, together with the source vessels, en bloc. The source vessels were injected with latex and processed using a new, accelerated diaphanisation technique. This quickly rendered tissue transparent, allowing the injected vessels to be visualised. Each navicular was then reconstructed using a digital microscribe, allowing a three dimensional virtual model of the bone to be assessed. The terminal points of each vessel were then mapped onto this model, allowing the distribution of each source vessel to be determined. This study will provide the as yet unpublished information on the arterial supply of the human navicular bone. The data will also give quantifiable evidence of any areas consistently restricted to single-vessel supply, and those consistently supplied by multiple vessels. This may help to explain the propensity of this bone to develop disorders such as osteochondritis, avascular necrosis and stress fractures which often have a vascular aetiology

Peroneal tendon subluxation although rare, is a commonly misdiagnosed cause of lateral ankle pain and instability. The orientation and depth of the lateral retromalleolar groove is a major contributor to peroneal stability, but is little understood. We attempt to quantify the groove using three directional mapping techniques. Eight age and sex matched embalmed cadaveric feet were dissected to expose the peroneal tendons and the retromalleolar groove. A hand held digitiser was used to map the version and inclination of the groove in a 3D virtual environment. The length and depth of the groove and its orientation were calculated using the cartilage boundary and the centroid of the curved surface. Four male and four female specimens (mean age 80 Yrs) were studied. The groove was noted to be concave in 62%, flat in 25 % and concave in 12.5 %. Flatter groove were more commonly noted in (2/4) females. There was a significant difference in length and width of the groove between male and female feet. The mean length of the groove in male specimens was 6.2cm (5.4–6.7cm), and in female specimens 5.5cm (4.4–5.9cm). The mean width in males was 5.3mm (5.0–6.1mm) and in females 4.5mm (3.7–5.3mm). There was no significant difference noted in the depth of the groove between male and female feet. The mean depth in males was 2.3mm (0.8–3.1) and in female 2.2mm (0–2.4mm). Knowledge of peroneal groove geometry in treatment of peroneal tendon instability is important. There appears to be a consistent difference in the anatomy of the groove between the sexes. Although men have longer and wider grooves than woman, the depth is the same in both sexes

Aims

Functional rehabilitation has become an increasingly popular treatment for Achilles tendon rupture (ATR), providing comparably low re-rupture rates to surgery, while avoiding risks of surgical complications. Limited evidence exists on whether gap size should affect patient selection for this treatment option. The aim of this study was to assess if size of gap between ruptured tendon ends affects patient-reported outcome following ATR treated with functional rehabilitation.