Background. The complex deformities in cavovarus feet may be difficult to assess and understand. Weight-bearing CT (WBCT) is increasingly used to evaluate complex deformities. However, the bone axes may be difficult to calculate in the setting of severe deformity. Computer-assisted 3D-axis calculation is a novel approach that may allow for more accurate assessment of foot alignment / deformity. The aim of this study was to assess differences in measurements done manually on 2D slices of WBCT versus 3D computer models in normal and cavus feet. Methods. We retrospectively analyzed WBCT scans from 16 normal and 16 cavus feet in patients with Charcot-Marie Tooth. Eight measurements were assessed: Talus-1. st. metatarsal angle (axial plane), Forefoot arch angle (coronal plane), and Meary's angle, calcaneal pitch, cuneiform to floor, cuneiform to skin, navicular to floor and navicular to skin distance (sagittal plane). 2D measurements were performed manually and 3D measurements were performed using specialised software (BoneLogic, DISIOR). Results. There was no significant difference in the measured variables (2D manual versus 3D automated) in normal feet. In the cavus group, 3D assessment calculated increased values for the sagittal angles: Meary's 7.3 degrees greater (p = 0.004), calcaneal pitch 2.4 degrees greater (p = 0.011)), and lower values for the axial talus-1. st. MT angle, 10.6 degrees less (p = 0.001). Conclusion. There were no significant differences in the normal group. This suggests 3D automated techniques can reliably assess the alignment of bony axes. However, the 3D axis calculations suggest there may be greater sagittal and lesser axial deformity in cavus feet than measured by 2D techniques. This discrepancy may be on account of the rotation seen in cavovarus feet, which may not be readily assessed manually. 3D automated measurements may therefore have a role in better assessing and classifying the cavus foot which may ultimately help inform treatment algorithms

Aims. The aims of this study were to evaluate the morphology of the ankle in patients with an osteochondral lesion of the talus using 3D CT, and to investigate factors that predispose to this condition. Patients and Methods. The study involved 19 patients (19 ankles) who underwent surgery for a medial osteochondral lesion (OLT group) and a control group of 19 healthy patients (19 ankles) without ankle pathology. The mean age was significantly lower in the OLT group than in the control group (27.0 vs 38.9 years; p = 0.02). There were 13 men and six women in each group. 3D CT models of the ankle were made based on Digital Imaging and Communications in Medicine (DICOM) data. The medial malleolar articular and tibial plafond surface, and the medial and lateral surface area of the trochlea of the talus were defined. The tibial axis-medial malleolus (TMM) angle, the medial malleolar surface area and volume (MMA and MMV) and the anterior opening angle of the talus were measured. Results. The mean TMM angle was significantly larger in the OLT group (34.2°, . sd. 4.4°) than in the control group (29.2°, . sd. 4.8°; p = 0.002). The mean MMA and MMV were significantly smaller in the OLT group than in the control group (219.8 mm. 2. , . sd. 42.4) vs (280.5 mm. 2. , . sd. 38.2), and (2119.9 mm. 3. , . sd. 562.5) vs (2646.4 mm. 3. , . sd. 631.4; p < 0.01 and p = 0.01, respectively). The mean anterior opening angle of the talus was significantly larger in the OLT group than in the control group (15.4°, . sd. 3.9°) vs (10.2°, . sd. 3.6°; p < 0.001). Conclusion. 3D CT measurements showed that, in patients with a medial osteochondral lesion of the talus, the medial malleolus opens distally, the MMA and MMV are small, and the anterior opening angle of the talus is large. This suggests that abnormal morphology of the ankle predisposes to the development of osteochondral lesions of the talus. Cite this article: Bone Joint J 2018;100-B:1487–90

Objective. The objective of this study was to evaluate the rotation and translation of each joint in the hindfoot and compare the load response in healthy feet with that in stage II posterior tibial tendon dysfunction (PTTD) flatfoot by analysing the reconstructive three-dimensional (3D) computed tomography (CT) image data during simulated weight-bearing. . Methods. CT scans of 15 healthy feet and 15 feet with stage II PTTD flatfoot were taken first in a non-weight-bearing condition, followed by a simulated full-body weight-bearing condition. The images of the hindfoot bones were reconstructed into 3D models. The ‘twice registration’ method in three planes was used to calculate the position of the talus relative to the calcaneus in the talocalcaneal joint, the navicular relative to the talus in talonavicular joint, and the cuboid relative to the calcaneus in the calcaneocuboid joint. Results. From non- to full-body-weight-bearing condition, the difference in the talus position relative to the calcaneus in the talocalcaneal joint was 0.6° more dorsiflexed (p = 0.032), 1.4° more everted (p = 0.026), 0.9 mm more anterior (p = 0.031) and 1.0 mm more proximal (p = 0.004) in stage II PTTD flatfoot compared with that in a healthy foot. The navicular position difference relative to the talus in the talonavicular joint was 3° more everted (p = 0.012), 1.3 mm more lateral (p = 0.024), 0.8 mm more anterior (p = 0.037) and 2.1 mm more proximal (p = 0.017). The cuboid position difference relative to the calcaneus in the calcaneocuboid joint did not change significantly in rotation and translation (all p ≥ 0.08). . Conclusion. Referring to a previous study regarding both the cadaveric foot and the live foot, joint instability occurred in the hindfoot in simulated weight-bearing condition in patients with stage II PTTD flatfoot. The method used in this study might be applied to clinical analysis of the aetiology and evolution of PTTD flatfoot, and may inform biomechanical analyses of the effects of foot surgery in the future. Cite this article: Bone Joint Res 2013;2:255–63

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. The morphology of medial malleolar fracture is highly variable and difficult to characterize without 3D reconstruction. There is also no universally accepeted classification system. Thus, we aimed to characterize fracture patterns of the medial malleolus and propose a classification scheme based on 3D CT reconstruction. Methods. We retrospectively reviewed 537 consecutive cases of ankle fractures involving the medial malleolus treated in our institution. 3D fracture maps were produced by superimposing all the fracture lines onto a standard template. We sliced fracture fragments and the standard template based on selected sagittal and coronal planes to create 2D fracture maps, where angles α and β were measured. Angles α and β were defined as the acute angles formed by the fracture line and the horizontal line on the selected planes. Results. A total of 121 ankle fractures were included. We revealed several important fracture features, such as a high correlation between posterior collicular fractures and posteromedial fragments. Moreover, we generalized the fracture geometry into three recurrent patterns on the coronal view of 3D maps (transverse, vertical, and irregular) and five recurrent patterns on the lateral view (transverse, oblique, vertical, Y-shaped, and irregular). According to the fracture geometry on the coronal and lateral view of 3D maps, we subsequently categorized medial malleolar fractures into six types based on the recurrent patterns: anterior collicular fracture (27 type I, 22.3%), posterior collicular fracture (12 type II, 9.9%), concurrent fracture of anterior and posterior colliculus (16 type III, 13.2%), and supra-intercollicular groove fracture (66 type IV, 54.5%). Therewere three variants of type IV fractures: transverse (type IVa), vertical (type IVb), and comminuted fracture (type IVc). The angles α and β varied accordingly. Conclusion. Our findings yield insight into the characteristics and recurrent patterns of medial malleolar fractures. The proposed classification system is helpful in understanding injury mechanisms and guiding diagnosis, as well as surgical strategies. Cite this article: Bone Joint J 2021;103-B(5):931–938

Background. Weightbearing computed tomography scans allow for better understanding of foot alignment in patients with Progressive Collapsing Foot Deformity. However, soft tissue integrity cannot be assessed via WBCT. As performing both WBCT and magnetic resonance imaging is not cost effective, we aimed to assess whether there is an association between specific WBCT and MRI findings. Methods. A cohort of 24 patients of various stages of PCFD (mean age 51±18 years) underwent WBCT scans and MRI. In addition to signs of sinus tarsi impingement, four three-dimensional measurements (talo-calcaneal overlap, talo-navicular coverage, Meary's angle axial/lateral) were obtained using a post processing software (DISIOR 2.1, Finland) on the WBCT datasets. Sinus tarsi obliteration, spring ligament complex and tibiospring ligament integrity, as well as tibialis posterior tendon degeneration were evaluated with MRI. Statistical analysis was performed for significant (P<0.05) correlation between findings. Results. None of the assessed 3D measurements correlated with spring ligament complex or tibiospring ligament tears. Age, body mass index, and TCO were associated with tibialis posterior tendon tears. 75% of patients with sinus tarsi impingement on WBCT also showed signs of sinus tarsi obliteration on MRI. Of the assessed parameters, only age and BMI were associated with sinus tarsi obliteration diagnosed on MRI, while the assessed WBCT based 3D measurements were, with the exception of MA axial, associated with sinus tarsi impingement. Conclusion. While WBCT reflects foot alignment and indicates signs of osseous impingement in PCFD patients, the association between WBCT based 3D measurements and ligament or tendon tears in MRI is limited. Partial or complete tears of the tibialis posterior tendon were only detectable in comparably older and overweight PCFD patients with an increased TCO. WBCT does not replace MRI in diagnostic value. Both imaging options add important information and may impact decision-making in the treatment of PCFD patients

Aims. The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan. Methods. We reviewed a total of 37 ankles (34 patients) that had undergone bone grafting for periprosthetic bone cysts. A CT scan was performed one year after bone grafting to check the status of graft incorporation. For accurate analysis of cyst volumes and their postoperative changes, 3D-reconstructed CT scan processed with 3D software was used. For functional outcomes, variables such as the Ankle Osteoarthritis Scale score and the visual analogue scale for pain were measured. Results. Out of 37 ankles, graft incorporation was successful in 30 cases. Among the remaining seven cases, four (10.8%) exhibited cyst re-progression, so secondary bone grafting was needed. After secondary bone grafting, no further progression has been noted, resulting in an overall 91.9% success rate (34 of 37) at a mean follow-up period of 47.5 months (24 to 120). The remaining three cases (8.1%) showed implant loosening, so tibiotalocalcaneal arthrodesis was performed. Functional outcomes were also improved after bone grafting in all variables at the latest follow-up (p < 0.05). The mean incorporation rate of the grafts according to the location of the cysts was 84.8% (55.2% to 96.1%) at the medial malleolus, 65.1% (27.6% to 97.1%) at the tibia, and 81.2% (42.8% to 98.7%) at the talus. Smoking was identified as a significant predisposing factor adversely affecting graft incorporation (p = 0.001). Conclusion. Bone grafting for periprosthetic bone cysts following primary TAA is a reliable procedure with a satisfactory success rate and functional outcomes. Regular follow-up, including CT scan, is important for the detection of cyst re-progression to prevent implant loosening after bone grafting. Cite this article: Bone Joint J 2024;106-B(5):475–481

Introduction. The treatment of posterior malleolar fractures is developing. Mason and Molloy (Foot Ankle Int. 2017 Nov;38(11):1229-1235) identified only 49% of posterior malleolar rotational pilon type fractures had syndesmotic instabilities. This was against general thinking that fixation of such a fragment would stabilize the syndesmosis. Methods. We examined 10 cadaveric lower limbs that had been preserved for dissection at the Human Anatomy and Resource Centre at Liverpool University in a solution of formaldehyde. The lower limbs were carefully dissected to identify the ligamentous structures on the posterior aspect of the ankle. To compare the size to the rotational pilon posterior malleolar fracture (Mason and Molloy 2A and B) we gathered information from our posterior malleolar fracture database. 3D CT imaging was analysed using our department PACS system. Results. The PITFL insertion on the posterior aspect of the tibia is very large. The average size of insertion was 54.9×47.1mm across the posterior aspect of the tibia. Medially the PITFL blends into the sheath of tibialis posterior and laterally into the peroneal tendon sheath. 78 posterior lateral and 35 posterior medial fragments were measured. On average, the lateral to medial size of the posteromalleolar fragment was 24.5mm in the posterolateral fragment, and 43mm if there is a posteromedial fragment present also. The average distal to proximal size of the posterolateral fragment was 24.5mm and 18.5mm for the posteromedial fragment. Conclusion. The PITFL insertion on the tibia is broad. In comparison to the average size of the posterior malleolar fragments, the PITFL insertion is significantly bigger. Therefore, for a posterior malleolar fracture to cause posterior syndesmotic instability, a ligamentous injury will also have to occur. This explains the finding by Mason and Molloy that only 49% of type 2 injuries had a syndesmotic injury on testing

Introduction. Pes cavovarus is a foot deformity that can be idiopathic (I-PC) or acquired secondary to other pathology. Charcot-Marie-Tooth disease (CMT) is the most common adult cause for acquired pes cavovarus deformity (CMT-PC). The foot morphology of these distinct patient groups has not been previously investigated. The aim of this study was to assess if morphological differences exist between CMT-PC, I-PC and normal feet (controls) using weightbearing computed tomography (WBCT). Methods. A retrospective analysis of WBCT scans performed between May 2013 and June 2017 was undertaken. WBCT scans from 17 CMT-PC, 17 I-PC and 17 healthy normally-aligned control feet (age-, side-, sex- and body mass index-matched) identified from a prospectively collected database, were analysed. Eight 2-dimensional (2D) and three 3-dimensional (3D) measurements were undertaken for each foot and mean values in the three groups were compared using one-way ANOVA with the Bonferroni correction. Results. Significant differences were observed between CMT-PC or I-PC and controls (p< 0.05). Two-dimensional measurements were similar in CMT-PC and I-PC, except for forefoot arch angle (p= 0.04). 3D measurements (foot and ankle offset, calcaneal offset and hindfoot alignment angle) demonstrated that CMT-PC exhibited more severe hindfoot varus malalignment than I-PC (p= 0.03, 0.04 and 0.02 respectively). Discussion. CMT-related cavovarus and idiopathic cavovarus feet are morphologically different from healthy feet, and CMT feet exhibit increased forefoot supination and hindfoot malalignment compared to idiopathic forms. The use of novel three-dimensional analysis may help highlight subtle structural differences in patients with similar foot morphology but aetiologically different pathology

Despite advancements, revision rates following total ankle replacement (TAR) are high in comparison to other total joint replacements. This explant analysis study aimed to investigate whether there was appreciable metal particulate debris release from various contemporary TARs by describing patterns of material loss. Twenty-eight explanted TARs (9 designs: 3 fixed and 6 mobile bearing), revised for any reason, were studied. The articulating surfaces of the metal tibial and talar components as well as the polyethylene insert were assessed for damage features using light microscopy. Based on the results of the microscopic analysis, scanning electron microscopy with energy dispersive X-ray spectroscopy was performed to determine the composition of embedded debris identified, as well as non-contacting 3D profilometry. Pitting, indicative of material loss, was identified on the articulating surfaces of 54% of tibial components and 96% of talar components. Bearing constraint was not found to be a factor, with similar proportions of fixed and mobile bearing metal components showing pitting. More cobalt-chromium than titanium alloy tibial components exhibited pitting (63% versus 20%). Significantly higher average surface roughness (Sa) values were measured for pitted areas in comparison to unpitted areas of these metal components (p<0.05). Additionally, metallic embedded debris (cobalt-chromium likely due to pitting of the tibial and talar components or titanium likely from loss of their porous coatings) was identified in 18% of polyethylene inserts. The presence of hard 3. rd. body particles was also indicated by macroscopically visible sliding plane scratching, identified on 79% of talar components. This explant analysis study demonstrates that metal debris is released from the articulating surfaces and the coatings of various contemporary TARs, both fixed and mobile bearing. These findings suggest that metal debris release in TARs may be an under-recognised issue that should be considered in the study of painful or failed TAR moving forwards

Introduction. Charcot neuroarthropathy is a debilitating condition that frequently leads to skeletal instability, and has an increased risk of ulceration leading to infection and amputation. However, surgical reconstruction may offer limb salvage and restauration of an ulcer-free, plantigrade stable foot for functional weight-bearing. We report on our case series according to a prospective protocol and analyse factors leading to a favourable outcome. Methods. We report a prospective follow-up of 62 patients undergoing Charcot reconstruction, May 2014- Jan 2022, by two surgeons. Peripheral vascular disease was routinely assessed using Duplex scan and major arterial disease was treated before reconstruction. Utilising 3D modelling, pre-operative planning and standardised osteotomies, we performed anatomical correction with radiological evidence. Definitive fixation was undertaken with internal fixation to stabilise the hindfoot. Multivariant analysis was performed to assess risk factors for failure (P>0.05 statistical significance). Results. 59 feet were included, 3 patients did not progress to definitive surgery and 3 patients had bilateral surgery. 62.7% patients were male with an average age of 56, 88.13% had Type 2 diabetes, 56% were hypertensive, 14% were on dialysis. Twenty (54.1%) single stage reconstructions had pre-operative ulceration, 3 pts had ischaemic heart disease and 36 pts had evidence of peripheral arterial disease. 81% of patients achieved normalisation of the 3 out of 4 anatomical angles (P<0.05). Two patients (3.1%) required metalwork removal for infection and limb salvage, 11 (18.6%) had delayed wound healing. Survivorship was 97% at 3yrs, and 94% at 6yrs, however if pre-existing vascular disease was present, it was 94% at 3yrs 85.3% at 6yrs. All patients were mobile at a 3 years mean follow up. Conclusion. Careful patient selection, multidisciplinary team and anatomic reconstruction led to predictable outcomes and functional limb salvage. Pre-operative vascular compromise led to a slight reduction in survivorship, but no major amputation

Ankle fusion (AF), a durable intervention for ankle arthritis, has been the management of choice but restricts mobility. Recently, total ankle replacement (TAR) has been offered to patients looking to maintain mobility. The aim was to compare the biomechanics of AF and TAR while walking on inverted and everted slopes which create a greater demand for complex foot mobility than level walking. A ten-camera motion detection setup captured trials as patients walked in both directions over a 5⁰ lateral slope with embedded force plates. Moments (Nm/Kg) across the knee and ankle were exported from Visual 3D in the sagittal and frontal plane, and data were reported as means with 95% confidence intervals. 15 patients were recruited (6 TAR, 9 AF). The median age, follow-up and BMI was 67 years, 4 years and 35.8 kg/m² in AF, and 73 years, 7 years and 28.1 kg/m² in TAR, respectively. During inverted slope walking (4 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.38 (0.37–0.39) vs AF 0.37 (0.27–0.52) and (ii) the ankle: TAR 0.20 (0.13–0.27) vs AF 0.25 (0.18–0.32), and extension moments across (i) the knee: TAR 0.68 (0.38–0.97) vs AF 0.85 (0.69–1.01) and (ii) the ankle: TAR 1.46 (1.30–1.62) vs AF 1.30 (1.08–1.52). During everted walking (5 TAR, 7 AF), abduction moments across (i) the knee: TAR 0.41 (0.30–0.52) vs AF 0.46 (0.27–0.66) and (ii) the ankle: TAR 0.24 (0.11–0.38) vs AF 0.26 (0.18–0.33), and extension moments across (i) the knee: TAR 0.76 (0.54–0.99) vs AF 0.93 (0.72–1.14) and (ii) the ankle: TAR 1.39 (1.19–1.59) vs AF 1.26 (1.04–1.48). There were no differences in abduction moments during inverted or everted slope walking. However, patients with AF had increased extension moments across the knee, particularly on inverted slopes, suggesting that AF creates a greater demand for knee compensation than TAR

Aims

The Chopart joint complex is a joint between the midfoot and hindfoot. The static and dynamic support system of the joint is critical for maintaining the medial longitudinal arch of the foot. Any dysfunction leads to progressive collapsing flatfoot deformity (PCFD). Often, the tibialis posterior is the primary cause; however, contrary views have also been expressed. The present investigation intends to explore the comprehensive anatomy of the support system of the Chopart joint complex to gain insight into the cause of PCFD.

Aims

The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant.

Introduction:. Cone Based CT (CBCT) scanning uses a point source and a planar detector with parallel data acquisition and volumetric coverage of the area of interest. The pedCAT (Curvebeam USA) scanner is marketed as a low radiation dose, compact, faster and inexpensive CT scanner that can be used to obtain both non- weightbearing and true 3 dimensional weightbearing views. Method:. A review of the first 100 CBCT scanning in our unit has been performed to assess ease of scanning, imaging time, radiation dose and value of imaging as opposed to conventional imaging. Results:. A pedcat CT scan was available within minutes of the request, similar to plain radiographs but much earlier than a 6 week delay for a patient to attend a new appointment for a conventional CT. All patients returned to see the clinician for a clinical decision in the same NHS clinic and did not require a new clinic visit; illustrative cases include fracture/subluxation detection, surgical planning, extent of arthritis and 3D assessment of union of arthrodeses. All patients were able to transfer to the scanner with ease and the imaging time was 10 times than a conventional CT. The radiation dose to the patients was 9% that of a full gantry system. Weightbearing CT scanning enabled a 3D evaluation of reduction of joint space and ankle/hindfoot alignment. Anterior ankle and sesamoid impingement have been diagnosed in patients with previously obscure pain. Conclusion:. 3D Cone Beam imaging has been found to be easily accessible, rapidly performed and safer to the patient in providing a lower radiation dose. Weightbearing 3D imaging provides additional diagnostic information

Background. Talar neck fractures occur infrequently and are associated with high complication rates. Anatomical restoration of articular congruity is important. Adequate exposure and stable internal fixation of these fractures are challenging. Aims. We investigate the use of an anterior extensile approach for exposure of these fractures and their fixation by screws introduced through the talo-navicular articulation. We also compare the quality and quantity of exposure of the talar neck obtained by this approach with the commonly described combined medial/lateral approaches. Materials and Methods. An anterior approach to the talus between the tibialis anterior and the extensor hallucis longus tendons protecting both the superficial and deep peroneal nerves was performed on 5 fresh frozen cadaveric ankles . The surface area of talar neck accessible was measured using an Immersion Digital Microscibe and analysed with Rhinoceros 3D graphics package. Standard antero-medial and antero –lateral approaches were also carried out on the same ankles, and similar measurements taken. Seven patients with talar neck fractures (4 Hawkins Type II and 3 Hawkins Type III) who underwent operative fixation using this approach with parallel cannulated screws through the talo-navicular joint were followed and the clinical radiological outcomes were recorded. Results. 3D mapping demonstrated that talar surface area visible by the anterior approach (mean 1200sqmm) is consistently superior to that visible by either the medial or lateral approaches in isolation or in combination (mean medial 350sqmm, mean lateral 600sqmm). Medial malleolar osteotomy does not offer any additional visualisation of the talar neck. 3D reconstruction of the area visualised by the three approaches confirms that the anterior approach provides superior access to the entirety of the talar neck. 5 male and 2 female patients (mean age -) were reviewed at a mean follow up period of 6 months. All had anatomical articular restoration, and no wound problems. None developed non or AVN. There were no symptoms referable to the talo-navicular joints which showed no evidence of any secondary changes on the radiographs. Discussion. The anterior extensile approach offers superior visualisation of the talar neck in comparison to other approaches for anatomical articular restoration. Surgical morbidity with this approach is low, and introduction of screws through the talo-navicular joint allows stable fixation of talar neck fractures along the axis of the bone. We argue that this approach is safe, adequate and has the potential to cause least vascular disruption

Introduction. The exact action of the Peroneus Longus muscle on the foot is not fully understood. It is involved in a number of pathological processes like tendonitis, tenosynovitis, chronic rupture and neurological conditions. It is described as having a consistent insertion to the base of the first metatarsal, but there have also been reports of significant variations and additional slips. Our aim was to further clarify the anatomy of the main insertion of the Peroneus Longus tendon and to describe the site and frequency of other variable insertion slips. Methods and Materials. The course of the distal peroneus longus tendon and its variable insertion was dissected in 12 embalmed, cadaveric specimens. The surface area of the main insertion footprint and angle of insertion was measured using an Immersion Digital Microscribe and 3D mapping software. The site and frequency of the other insertion slips is also presented. Results. There was a consistent, main insertion to the infero-lateral aspect of the first metatarsal in all specimens. The only additional slip was to the medial cuneiform. This did not increase the total footprint. Discussion. The main footprint of the Peroneus Longus tendon is on the first metatarsal. There was an additional slip to the medial cuneiform in 33% of our specimens. Although we are unsure about the significance of this additional slip, we hope it will lead to a better understanding of the mechanism of action of this muscle and its role both in the normal and pathological foot

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

Introduction:. There is paucity of literature on Gait analysis following Total Ankle Replacement (TAR). We aimed to study changes to gait after successful Mobility TAR. Methods:. 20 patients who underwent a primary TAR, with a diagnosis of either OA or PTOA were recruited between October 2008 and March 2011. Gait analysis was carried out using the Helen Hayes marker system with VICON 3D opto-electric system pre-operatively, 3, 6 and 12 months post-operatively. Ankle kinematics and spatio-temporal parameters of gait were studied. Results:. 20 patients were included. Mean age was 63.6 years (Range 43–84), mean BMI was 29.6 ± 4.08. Diagnosis was OA in 12 (52.2%) and PTOA in 8 (34.8%). Results showed increase in average and maximum range of dorsiflexion from (3° to 7°) and (11° to 17°) respectively from pre-op to 1 year, but statistically not significant (p>0.05). Of the temporal variables, Average Cadence increased from Pre-op to 1 year (102 to 106 steps/min); double support (0.35% to 0.31%), single support (0.41% to 0.39%) and toe off point at gait cycle (63.9% to 62.4%) decreased from pre-op to 1 year, but failed to achieve statistical significance (p>0.05). For distance variables, Step length showed a significant increase from pre-op to 1 year (0.21m/s to 0.58m/s; p<0.001); stride length increased (1.05m/s to 1.13m/s), step time and stride time decreased (0.60 secs to 0.58 secs) and (1.19 to 1.14 secs) respectively and Walking speed increased (0.90m/s to 1.00m/s) from pre-op to 1 year, but statistically not significant (P>0.05). Conclusion:. There was significant improvement in step length after TAR from pre-op to 1 year. Although the results showed a trend for improvement in average dorsiflexion, average cadence, stride length, walking speed, decreased step and stride length times, which showed improvement in walking pattern in these group of patients, but failed to achieve statistical significance

Introduction. Shoes with a rocker sole are commonly prescribed following forefoot surgery to redistribute pressure towards the heel. By shifting the body weight backwards, does the rocker shoe adversely effect balance and so disturb normal muscle activity? This study investigated the effects of the Darco post-operative shoe, and the impact of a contralateral shoe raise, on forefoot pressure, posture and balance. Materials and Methods. Fourteen healthy volunteers were investigated (age 36 ±10.8 yrs 11 females) either wearing (1) left Darco shoe and right standard shoe with/without a 5cm temporary shoe raise (Algeos Ltd) (2) two standard shoes. Postural sway was measured while standing with eyes open/closed and on/off a foam block. Dynamic balance was measured while stepping forwards/backwards and walking. Measurements of foot pressure (TECSKAN Inc USA), 3D body motion (Codamotion, UK) and surface electromyography of lower limb muscles were taken. Results were analysed using a repeated measures ANOVA. Results. The rocker shoe was associated with a 84% (±14) decrease in mean peak medial forefoot pressure a posterior shift of 0.9 cm (±1) in the centre of pressure (COP) and a 223% (±127) increase in tibialis anterior activity (P<0.05). Postural sway and whole body motion while stepping did not change. The shoe raise decreased peak loading in the Darco shoe and resulted in a smaller shift in the COP. Discussion and Conclusions. The increase in tibialis anterior activity helps maintain balance by compensating for the posterior shift in the centre of pressure. In people with weakness in the anterior muscles a rocker shoe may adversely affect balance. A contralateral shoe raise reduces the posterior shift in the COP but, due to a decrease in total loading through the whole foot, forefoot offloading is similar. A contralateral shoe raise may therefore aid balance while maintaining forefoot offloading