Tendinopathy can commonly occur around the foot and ankle resulting in isolated rupture, debilitating pain and degenerative foot deformity. The pathophysiology and key cells involved are not fully understood. This is partly because the dense collagen matrix that surrounds relatively few resident cells limits the ability of previous techniques to identify and target those cells of interest. In this study, we apply novel single cell RNA sequencing (CITE-Seq) techniques to healthy and tendinopathic foot/ankle tendons. For the first time we have identified multiple sub-populations of cells in human tendons. These findings challenge the view that there is a single principal tendon cell type and open new avenues for further study. Healthy tendon samples were obtained from patients undergoing tendon transfer procedures; including tibialis posterior and FHL. Diseased tendon samples were obtained during debridement of intractable Achilles and peroneal tendinopathy, and during fusion of degenerative joints. Single cell RNA sequencing with surface proteomic analysis identified 10 sub-populations of human tendon derived cells. These included groups expressing genes associated with fibro-adipogenic progenitors (FAPs) as well as ITGA7+VCAM1- recently described in mouse muscle but, as yet, not human tendon. In addition we have identified previously unrecognised sub-classes of collagen type 1 associated tendon cells. Each sub-class expresses a different set of extra-cellular matrix genes suggesting they each play a unique role in maintaining the structural integrity of normal tendon. Diseased tendon harboured a greater proportion of macrophages and cytotoxic lymphocytes than healthy tendon. This inflammatory response is potentially driven by resident tendon fibroblasts which show increased expression of pro-inflammatory cytokines. Finally, identification of a previously unknown sub-population of cells found predominantly in tendinopathic tissue offers new insight into the underlying pathophysiology. Further work aims to identify novel proteins targets for possible therapeutic pathways

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. Fusion represents an effective treatment option in patients affected by end-stage arthritis. To minimise the risk of non-union following fusion, biological preparations such as bone marrow aspirate concentrate (BMAC) are commonly used intra-operatively. Mechanotransduction represents an emerging field of research whereby physical stimuli can be used to modulate the behaviour and differentiation of cells. Blast waves (a subtype of shock waves) are one such physical stimulus. The aim of this study was to investigate whether the osteogenic potential of BMAC can be enhanced using a blast wave, and thus improve its efficacy in fusion surgery. Methods. Human BMAC samples were obtained from three healthy patients and exposed to a single blast wave (peak overpressure= 50psi), before being placed in a suspension of mesenchymal stem cells, to represent the biological environment of the fusion site. Three test groups were used: MSC (the experimental control); MSC + BMAC; MSC + BMAC + blast wave. Calcium mineralisation assays were performed on the MSCs on Day 7 and 14 to assess for osteoblastic transformation. Results. Calcium mineralisation on Day 7 was significantly increased in the MSC + BMAC group compared to the MSC group (mean percentage change 42.12 vs 0.0, p=0.012). The MSC + BMAC + blast wave group also demonstrated significantly increased levels compared to the MSC + BMAC group (84.56 vs. 42.14, p = 0.039). The difference in calcium mineralisation between the MSC and MSC + BMAC + blast wave groups was strongly significant (0.00 vs. 84.56, p = 0.003). Conclusion. Exposure of BMAC to a single blast wave enhances its osteogenic potential. This represents a potential novel way to improve healing following fusion surgery and reduce the rates of non-union

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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.

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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.

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This scoping review aims to identify patient-related factors associated with a poorer outcome following total ankle arthroplasty (TAA).

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This cross-sectional study aimed to investigate the in vivo ankle kinetic alterations in patients with concomitant chronic ankle instability (CAI) and osteochondral lesion of the talus (OLT), which may offer opportunities for clinician intervention in treatment and rehabilitation.

Lisfranc injuries were previously described as fracture-dislocations of the tarsometatarsal joints. With advancements in modern imaging, subtle Lisfranc injuries are now more frequently recognized, revealing that their true incidence is much higher than previously thought. Injury patterns can vary widely in severity and anatomy. Early diagnosis and treatment are essential to achieve good outcomes. The original classification systems were anatomy-based, and limited as tools for guiding treatment. The current review, using the best available evidence, instead introduces a stability-based classification system, with weightbearing radiographs and CT serving as key diagnostic tools. Stable injuries generally have good outcomes with nonoperative management, most reliably treated with immobilization and non-weightbearing for six weeks. Displaced or comminuted injuries require surgical intervention, with open reduction and internal fixation (ORIF) being the most common approach, with a consensus towards bridge plating. While ORIF generally achieves satisfactory results, its effectiveness can vary, particularly in high-energy injuries. Primary arthrodesis remains niche for the treatment of acute injuries, but may offer benefits such as lower rates of post-traumatic arthritis and hardware removal. Novel fixation techniques, including suture button fixation, aim to provide flexible stabilization, which theoretically could improve midfoot biomechanics and reduce complications. Early findings suggest promising functional outcomes, but further studies are required to validate this method compared with established techniques. Future research should focus on refining stability-based classification systems, validation of weightbearing CT, improving rehabilitation protocols, and optimizing surgical techniques for various injury patterns to ultimately enhance patient outcomes.

Cite this article: Bone Joint J 2024;106-B(12):1431–1442.

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To compare the cost-utility of removable brace compared with cast in the management of adult patients with ankle fracture.

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Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remains a challenge. A novel surgical technique named ‘tibial cortex transverse transport’ (TTT) has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In the present study, we explored the potential biological mechanisms of TTT surgery using various techniques in a rat TTT animal model.

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Arthroplasty has become increasingly popular to treat end-stage ankle arthritis. Iatrogenic posterior neurovascular and tendinous injury have been described from saw cuts. However, it is hypothesized that posterior ankle structures could be damaged by inserting tibial guide pins too deeply and be a potential cause of residual hindfoot pain.

Introduction. The prevalence of symptomatic osteoarthritis (OA) in the knee is 11–11% compared to 3.4–4.4% in the ankle. In addition to this, 70% of ankle arthritis is post-traumatic while the vast majority of knee arthritis is primary OA. Several reports have previously implicated biochemical differences in extracellular matrix composition between these joint cartilages; however, it is unknown whether there is an inherent difference in their transcriptome and how this might affect their respective functionality under load, inflammatory environment etc. Therefore, we have analysed the transcriptome of ankle and knee cartilage chondrocytes to determine whether this could account for the lower prevalence and altered aetiology of ankle OA. Methods. Human full-depth articular cartilage was taken from the talar domes (n=5) and the femoral condyles (n=5) following surgical amputation. RNA was extracted and next generation sequencing (NGS) performed using the NextSeq®500 system. Statistical analysis was performed to identify differentially regulated genes (p adj < 0.05). Data was analysed using Integrated Pathway Analysis software and genes of interest validated by quantitative PCR. Results. 809 genes were differentially expressed in this NGS study: 781 genes were significantly up-regulated and 27 significantly down-regulated in ankle cartilage with respect to knee. Preliminary analysis has identified several pathways which are differentially regulated including ‘inflammation mediated by cytokines’, ‘glutamate receptor pathway, ‘heterotrimeric-G-protein signalling pathways’, ‘WNT signalling’ and ‘integrin signalling’. Discussion. This is the first report identifying genes that are differentially expressed in ankle cartilage compared to the knee. Validation is currently being performed to ascertain the importance of these gene changes and correlation with their protein expression in the different joints. An understanding of the inherent biological differences in the cartilage between these two joints will provide invaluable insight into why the ankle is relatively spared from primary OA and the majority of ankle arthritis occurs following trauma

Lengthening of the conjoined tendon of the gastrocnemius aponeurosis and soleus fascia is frequently used in the treatment of equinus deformities in children and adults. The Vulpius procedure as described in most orthopaedic texts is a division of the conjoined tendon in the shape of an inverted V. However, transverse division was also described by Vulpius and Stoffel, and has been reported in some clinical studies. We studied the anatomy and biomechanics of transverse division of the conjoined tendon in 12 human cadavers (24 legs). Transverse division of the conjoined tendon resulted in predictable, controlled lengthening of the gastrocsoleus muscle-tendon unit. The lengthening achieved was dependent both on the level of the cut in the conjoined tendon and division of the midline raphé. Division at a proximal level resulted in a mean lengthening of 15.2 mm (. sd . 2.0, (12 to 19), which increased to 17.1 mm (. sd . 1.8, (14 to 20) after division of the midline raphé. Division at a distal level resulted in a mean lengthening of 21.0 mm (. sd. 2.0, (18 to 25), which increased to 26.4 mm (. sd . 1.4, (24 to 29) after division of the raphé. These differences were significant (p < 0.001). Cite this article: Bone Joint J 2014; 96-B:778–82

Objective. The main object of this study was to use a geometric morphometric approach to quantify the left-right symmetry of talus bones. . Methods. Analysis was carried out using CT scan images of 11 pairs of intact tali. Two important geometric parameters, volume and surface area, were quantified for left and right talus bones. The geometric shape variations between the right and left talus bones were also measured using deviation analysis. Furthermore, location of asymmetry in the geometric shapes were identified. . Results. Numerical results showed that talus bones are bilaterally symmetrical in nature, and the difference between the surface area of the left and right talus bones was less than 7.5%. Similarly, the difference in the volume of both bones was less than 7.5%. Results of the three-dimensional (3D) deviation analyses demonstrated the mean deviation between left and right talus bones were in the range of -0.74 mm to 0.62 mm. It was observed that in eight of 11 subjects, the deviation in symmetry occurred in regions that are clinically less important during talus surgery. . Conclusions. We conclude that left and right talus bones of intact human ankle joints show a strong degree of symmetry. The results of this study may have significance with respect to talus surgery, and in investigating traumatic talus injury where the geometric shape of the contralateral talus can be used as control. Cite this article: Bone Joint Res 2014;3:139–45

The AO Foundation advocates the use of partially threaded lag screws in the fixation of fractures of the medial malleolus. However, their threads often bypass the radiodense physeal scar of the distal tibia, possibly failing to obtain more secure purchase and better compression of the fracture. We therefore hypothesised that the partially threaded screws commonly used to fix a medial malleolar fracture often provide suboptimal compression as a result of bypassing the physeal scar, and proposed that better compression of the fracture may be achieved with shorter partially threaded screws or fully threaded screws whose threads engage the physeal scar. We analysed compression at the fracture site in human cadaver medial malleoli treated with either 30 mm or 45 mm long partially threaded screws or 45 mm fully threaded screws. The median compression at the fracture site achieved with 30 mm partially threaded screws (0.95 kg/cm. 2. (interquartile range (IQR) 0.8 to 1.2) and 45 mm fully threaded screws (1.0 kg/cm. 2 . (IQR 0.7 to 2.8)) was significantly higher than that achieved with 45 mm partially threaded screws (0.6 kg/cm. 2. (IQR 0.2 to 0.9)) (p = 0.04 and p < 0.001, respectively). The fully threaded screws and the 30mm partially threaded screws were seen to engage the physeal scar under an image intensifier in each case. The results support the use of 30 mm partially threaded or 45 mm fully threaded screws that engage the physeal scar rather than longer partially threaded screws that do not. A 45 mm fully threaded screw may in practice offer additional benefit over 30 mm partially threaded screws in increasing the thread count in the denser paraphyseal region. Cite this article: Bone Joint J 2013;95-B:1662–6

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In the context of tendon degenerative disorders, the need for innovative conservative treatments that can improve the intrinsic healing potential of tendon tissue is progressively increasing. In this study, the role of pulsed electromagnetic fields (PEMFs) in improving the tendon healing process was evaluated in a rat model of collagenase-induced Achilles tendinopathy.

Introduction:. Peroneal muscle weakness is a common pathology in foot and ankle surgery. Polio, charcot marie tooth disease and spina bifida are associated with varying degrees of peroneal muscle paralysis. Tibialis Posterior, an antagonist of the peroneal muscles, becomes pathologically dominant, causing foot adduction and contributes to cavus foot posture. Refunctioning the peroneus muscles would enhance stability in toe off and resist the deforming force of tibialis posterior. This study determines the feasibility of a novel tendon transfer between peroneus longus and gastrocnemius, thus enabling gastrocnemius to power a paralysed peroneus tendon. Method:. 12 human disarticulated lower limbs were dissected to determine the safety and practicality of a tendon transfer between peroneus longus and gastrocnemius at the junction of the middle and distal thirds of the fibula. The following measurements were made and anatomical relationships quantified at the proposed site of the tendon transfer: The distance of the sural nerve to the palpable posterior border of the fibula; the angular relationship of the peroneus longus tendon to gastrocnemius and the achilles tendon; the surgical field for the proposed tendon transfer was explored to determine the presence of hazards which would prevent the tendon transfer. Results:. The mean angle between the tendons of peroneus longus and gastrocnemius/achilles tendon was 3°. The sural nerve lies on average 30 mm posterior to the palpable posterior border of the fibula. There were no significant intervening structures to prevent the proposed tendon transfer. Conclusion:. The line of action of peroneus longus and gastrocnemius are as near parallel as to be functionally collinear. The action of gastrocnemius may be harnessed to effectively power a paralysed peroneus longus tendon, without significant loss of force owing to revectoring of forces. The surgical approach to effect such a tendon transfer is both safe and practical

When inserting a lag-screw across an arthrodesis, stress is concentrated under the screw head risking asymmetrical force distribution and fracture of the cortical bone bridge. The IO FiX (Extremity Medical, NJ USA) is a new intraosseous device comprising an X-Post on one side of and parallel to the arthrodesis and a lag-screw inserted through the head of the X-Post which reinforces the cortical bone bridge. The X-Post behaves as an internal washer improving force distribution across the arthrodesis. Being intraosseous, near to the neutral axis of bend also means the device is fatigue-resistant and soft tissue irritation is reduced. The IO FiX has not been independently verified and therefore we analysed its performance in a human cadaveric ankle model. Our null hypothesis was there is no difference in force generation and contact area in an ankle arthrodesis when the IO FiX is compared with partially-threaded lag-screws. We used ten randomized cadaver ankles with a mean age of seventy-one years (44–84 years) prepared with flat arthrodesis cuts. A Tek-scan (Boston, USA) pressure transducer was used to measure force and contact area produced when the IO FiX was compared with a standard lag-screw and washer. The median average force in the IO FiX group was 3.95 kg and 2.35 kg in the lag-screw group (p=<0.01 Wilcoxon signed-rank). The IO FiX was able to create a more uniform contact area within the arthrodesis with a median average of 3.41 cm. 2. compared with 2.42 cm. 2. in the lag-screw group (p=<0.03 Wilcoxon signed rank). Our results suggest the IO FiX improves force generation and contact area across the arthrodesis. With the theoretical advantages of reduced soft tissue irritation and a lower risk of fatigue failure, the IO FiX offers a significant advantage compared with traditional fixation techniques

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

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The aim of this study was to evaluate the functional outcome in patients undergoing implant removal (IR) after fracture fixation below the level of the knee.