Aims

Highly cross-linked polyethylene (HXLPE) greatly reduces wear in total hip arthroplasty, compared to conventional polyethylene (CPE). Cross-linking is commonly achieved by irradiation. This study aimed to compare the degree of cross-linking and in vitro wear rates across a cohort of retrieved and unused polyethylene cups/liners from various brands.

Background. Lisfranc fracture dislocations are uncommon injuries, which frequently require surgical intervention. Currently, there is varying evidence on the diagnostic utility of plain radiographs (XR) and CT in identifying Lisfranc injuries and concomitant fractures. Our aim was to identify the utility of XR as compared to CT, with the nul hypothesis that there was no difference in fracture identification. Methods. A retrospective assessment of patients who had sustained a Lisfranc injury between 2013 and 2022 across two trauma centres within the United Kingdom who underwent surgery. Pre-operative XR and CT images were reviewed independently by 2 reviewers to identify the presence of associated fractures. Results. A total of 175 patients were included. Our assessment identified that XR images significantly under-diagnosed all metatarsal and midfoot fractures. The largest discrepancies between XR and CT in their rates of detection were in fractures of the cuboid (5.7% vs 28%, p<0.001), medial cuneiform (20% vs 51%, p=0.008), lateral cuneiform (4% vs 36%, p=0.113), second metatarsal (57% vs 82%, p<0.001), third metatarsal (37% vs 61%, p<0.001) and fourth metatarsal (26% vs 43%, p<0.001). As compared to CT, the sensitivity of XR was low. The lowest sensitivity for identification however was lateral foot injuries, specifically fractures of the lateral cuneiform (sensitivity 7.94%, specificity 97.3%), cuboid (sensitivity 18.37%, specificity 99.21%), fourth (sensitivity 46.7%, specificity 89.80%) and fifth metatarsal (sensitivity 45.00%, specificity 96.10%). Conclusion. From our analysis, we can determine that XR significantly under-diagnoses associated injuries in patient sustaining an unstable Lisfranc injury, with lateral foot injuries being the worst identified. We advised the use of CT imaging in all cases for appropriate surgical planning

Introduction. Charcot neuroarthropathy is a limb threatening condition and the optimal surgical strategy for limb salvage in gross foot deformity remains unclear. We present our experience of using fine wire frames to correct severe midfoot deformity, followed by internal beaming to maintain the correction. Materials and Methods. Nine patients underwent this treatment between 2020–2023. Initial deformity correction by Ilizarov or hexapod butt frame was followed by internal beaming with a mean follow up of 11 months. A retrospective analysis of radiographs and electronic records was performed. Meary's angle, calcaneal pitch, cuboid height, hindfoot midfoot angle and AP Meary's angle were compared throughout treatment. Complications, length of stay and the number of operations are also described. Results. Mean age was 53 years (range:40–59). Mean frame duration was 3.3 months before conversion to beaming. Prior frame-assisted deformity correction resulted in consistently improved radiological parameters. Varying degrees of subsequent collapse were universal, but 5 patients still regained mobility and a stable, plantargrade, ulcer-free foot. Complications were common, including hardware migration (N=6,66%), breakage (N=2,22%), loosening (N=3,33%), infection (N=4,44%), 1 amputation and an unscheduled reoperation rate of 55%. Mean cumulative length of stay was 42 days. Conclusions. Aggressive deformity correction and internal fixation for Charcot arthropathy requires strategic and individualised care plans. Complications are expected for each patient. Patients must understand this is a limb salvage scenario. This management strategy is resource heavy and requires timely interventions at each stage with a well-structured MDT delivering care. The departmental learning points are to be discussed

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. Methods. The study was conducted on 40 adult embalmed cadaveric lower limbs. Chopart joint complexes were dissected, and the structures supporting the joint inferiorly were observed and noted. Results. The articulating bones exhibit features like a cuboid shelf and navicular beak, which appear to offer inferior support to the joint. The expanse of the spring ligament complex is more medial than inferior, while the superomedial part is more extensive than the intermediate and inferoplantar parts. The spring ligament is reinforced by the tendons in the superomedial part (the main tendon of tibialis posterior), the inferomedial part (the plantar slip of tibialis posterior), and the master knot of Henry positioned just inferior to the gap between the inferomedial and inferoplantar bundles. Conclusion. This study highlights that the medial aspect of the talonavicular articulation has more extensive reinforcement in the form of superomedial part of spring ligament and tibialis posterior tendon. The findings are expected to prompt further research in weightbearing settings on the pathogenesis of flatfoot. Cite this article: Bone Jt Open 2024;5(4):335–342

The December 2023 Foot & Ankle Roundup³⁶⁰ looks at: Subchondral bone cysts remodel after correction of varus deformity in ankle arthritis; 3D-printed modular endoprosthesis reconstruction following total calcanectomy; Percutaneous partial bone excision in the management of diabetic toe osteomyelitis; Hemiepiphysiodesis is a viable surgical option for Juvenile hallux valgus; Ankle arthroplasty vs arthrodesis: which comes out on top?; Patient-related risk factors for poorer outcome following total ankle arthroplasty; The Outcomes in Ankle Replacement Study.

Aim. The aim of this paper is to analyse the cause of neuropathic diabetic foot ulcers and discuss their preventive measures. Methods. Review of patients with foot ulcers managed in our diabetic MDT clinics since Feb 2018 were analysed. Based on this observation and review of pertinent literature, following observations were made. Results. Forefoot. Progressive hindfoot equinus from contraction of gastroc-soleus-tendo-Achilles complex, with additional contraction of tibialis posterior and peroneal longus muscles and, progressive plantar flexed metatarsal heads secondary to claw toe deformity results in increased forefoot plantar pressures. In patients with insensate feet, this result in ulcer formation under the metatarsal heads from shear stress when walking. Callosity under the metatarsal heads is the earliest clinical sign. Most patients by this time have fixed tightness of the muscle groups as assessed by negative Silfverskiold test. Percutaneous tendo-Achilles lengthening (TAL) has shown to reduce the mid-forefoot plantar pressures by 32% and ulcer healing in 96% of patients within 10 weeks (± 4 weeks). Additional z-lengthening of peroneal longus and tibialis posterior tendons helped in patients with big-toe and 5. th. metatarsal head ulcers. Proximal metatarsal osteotomies further reduce the forefoot pressures to near normality. Midfoot. Midfoot ulcers are secondary to rocker-bottom deformity a consequence of Charcot neuroarthropathy (CN). Hindfoot equinus as described and relative osteopenia from neurally mediated increased blood flow (neurovascular theory) and repeated micro-trauma (neurotraumatic theory) result in failure of medial column osseo-ligamentous structures. As the disease progress to the lateral column, the cuboid height drops resulting in a progressive rocker bottom deformity. The skin under this deformity gradually breaks down to ulceration. In the pre-ulcerative stages of midfoot CN, TAL has shown to stabilise the disease progression and in some patents’ regression of the disease process was noted. The lump can excised electively and the foot accommodated in surgical shoes. Hindfoot. These develop commonly at the pressure areas and bony exostosis in non-ambulatory patients. In ambulatory patients, the most common cause are factors that result in over lengthening of tendo-Achilles such as after TAL, spontaneous tears, or tongue-type fractures. Conclusions. Early identification of factors that result in plantar skin callosity and treating the deforming forces prevent progression to ulceration. Total contact cast without treatment of these deforming forces results in progression of these callosities to ulceration while in the cast or soon after completion of cast treatment

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This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model.

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To systematically review the efficacy of split tendon transfer surgery on gait-related outcomes for children and adolescents with cerebral palsy (CP) and spastic equinovarus foot deformity.

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Osteoarthritis (OA) is prevalent among the elderly and incurable. Intra-articular parathyroid hormone (PTH) ameliorated OA in papain-induced and anterior cruciate ligament transection-induced OA models; therefore, we hypothesized that PTH improved OA in a preclinical age-related OA model.

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Tenosynovial giant cell tumour (TGCT) is one of the most common soft-tissue tumours of the foot and ankle and can behave in a locally aggressive manner. Tumour control can be difficult, despite the various methods of treatment available. Since treatment guidelines are lacking, the aim of this study was to review the multidisciplinary management by presenting the largest series of TGCT of the foot and ankle to date from two specialized sarcoma centres.

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We aimed to describe the epidemiological, biological, and bacteriological characteristics of osteoarticular infections (OAIs) caused by Kingella kingae.

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The treatment of tibial aplasia is controversial. Amputation represents the gold standard with good functional results, but is frequently refused by the families. In these patients, treatment with reconstructive limb salvage can be considered. Due to the complexity of the deformity, this remains challenging and should be staged. The present study evaluated the role of femoro-pedal distraction using a circular external fixator in reconstructive treatment of tibial aplasia. The purpose of femoro-pedal distraction is to realign the limb and achieve soft tissue lengthening to allow subsequent reconstructive surgery.

The detailed biomechanical mechanism of annulus fibrosus under abnormal loading is still ambiguous, especially at the micro and nano scales. This study aims to characterize the alterations of modulus at the nano scale of individual collagen fibrils in annulus fibrosus after in-situ immobilization, and the corresponding micro-biomechanics of annulus fibrosus. An immobilization model was used on the rat tail with an external fixation device. Twenty one fully grown 12-week-old male Sprague-Dawley rats were used in this study. The rats were assigned to one of three groups randomly. One group was selected to be the baseline control group with intact intervertebral discs (n=7). In the other two groups, the vertebrae were immobilized with an external fixation device that fixed four caudal vertebrae (C7-C10) for 4 and 8 weeks, respectively. Four K-wires were fixed in parallel using two aluminum alloy cuboids which do not compress or stretch the target discs. The immobilized discs were harvested and then stained with hematoxylin/eosin, scanned using atomic force microscopy to obtain the modulus at both nano and micro scales, and analyzed the gene expression with real-time quantitative polymerase chain reaction. Significance of differences between the study groups was obtained using a two-way analysis of variance (ANOVA) with Fisher's Partial Least-Squares Difference (PLSD) to analyze the combined influence of immobilization time and scanning region. Statistical significance was set at P≤0.05. Compared to the control group, the inner layer of annulus fibrosus presented significant disorder and hyperplasia after immobilization for 8 weeks, but not in the 4 week group. The fibrils in inner layer showed an alteration in elastic modulus from 91.38±20.19MPa in the intact annulus fibrosus to 110.64±15.58MPa (P<0.001) at the nano scale after immobilization for 8 weeks, while the corresponding modulus at the micro scale also underwent a change from 0.33±0.04MPa to 0.47±0.04MPa (P<0.001). The upregulation of collagen II from 1±0.03 in control to 1.22±0.03 in 8w group (P = 0.003) was induced after immobilization, while other genes expression showed no significant alteration after immobilization for both 4 and 8 weeks compared to the control group (P>0.05). The biomechanical properties at both nano and micro scales altered in different degrees between inner and outer layers in annulus fibrosus after immobilization for different times. Meanwhile, the fibril arrangement disorder and the upregulation of collagen II in annulus fibrosus were observed using hematoxylin/eosin staining and real-time RT-PCR, respectively. These results indicate that immobilization not only influenced the individual collagen fibril at the nano scale, but also suggested alterations of micro-biomechanics and cell response. This work provides a better understanding of IVD degeneration after immobilization and benefits to the clinical treatment related to disc immobilization

Implant infection is an increasing problem in orthopedic surgery, especially due to progressive antibiotic resistance and an aging population with rising numbers of implantations. As a consequence, new strategies for infection prevention are necessary. In the previous study it was hypothesized that laser-structured implant surfaces favor cellular adhesion while hindering bacterial ongrowth and therewith contribute to reduce implant infections. Cuboid titanium implants (0.8 × 0.8 × 12 mm. 3. , n=34) were used. Seventeen were laser-structured by ultra-short pulsed laser ablation to create a spike structure; the others were polished and served as controls. In general anesthesia, implants were inserted in rat tibiae and infected with a S. aureus suspension. During a 21 day postoperative follow-up, daily clinical control was performed. Radiographs were taken at day 14 and day 21. After euthanasia, bacterial load and biofilm formation on the implant surface was evaluated semi quantitatively by confocal laser scanning microscopy and computational acquisition of bacteria and cells by Imaris®-software. Additionally, histology of the surrounding bone was performed. Clinically, no differences were observed between the groups. However, contrary to our hypothesis, bacterial load was increased in the laser-structured implant group although cellular adhesion was even more pronounced. Radiographical and histological evaluations showed increased bone alterations in the group with laser-structured implants compared to the control group. These findings did not confirm prior in vitro studies, where a reduction of bacterial load was found for similar surfaces and demonstrate the necessity of in vivo trials prior to the clinical use of new materials

To date there has been no material for endoprosthetics providing excellent resistance to abrasion and corrosion combined with great tensile strength, fracture toughness, and bending strength, as well as adequate biocompatibility. Carbon-fiber-reinforced silicon carbide (C/SiC, C/C-SiC or C/SiSiC) is as a ceramic compound a potentially novel biomaterial offering higher ductility and durability than comparable oxide ceramics. Aim of this investigation was to test the suitability of C/SiC ceramics as a new material for bearing couples in endoprosthetics. One essential quality that any new material must possess is biocompatibility. For this project the in-vitro biocompatibility was investigated by using cuboid like scaffolds made of CMC. To determine whether the material is suited as a lubricant partner in endoprosthetics, we measured its abrasion coefficient and wear tolerance against various antibodies. The C/SiC samples tested were produced via the Liquid Silicon Infiltration (LSI) of pyrolized porous fiber preforms made by warm-flow pressing free-flowing granulates on a hydraulic downstroking press with a heated die of the type HPS-S, 1000 kN. After preparation of the composites, the tribological characteristics are determined. Flexural strength was determined at room temperature according to DIN685-3 with an universal testing machine Z100 and the Young”s -modulus was carried out via resonant frequency-damping analysis RFDA. The samples”surface as well as cell adhesion and cell morphology were assessed via ESEM. The human osteoblast-like cell line MG-63 and human ostoeblast were used for cel culture ecperiments (WST, Live/dead, Cytotoxicity, cell morphology). Based on the raw data the mean value and the standard deviation were calculated. The Mann-Whitney-U-Test was used to evaluate the differences between experiment and control samples. The flexural strength at room temperature is approx. 180 MPa, while the elongation at break is about 0.13%. The Young”s modulus is detected between 120 and 150 GPa. The density lies between 2.5 and 3.0 g/cm. 3. We noted a friction coefficient µ between 0.31. The cell lines exhibited no morphological alterations, and adhered well to the C/SiC samples. Vitality was not impaired by contact with the ceramic composite. Cell growth was observed evenly distributed over a 21-day period. In the future, investigators aiming to apply this composite in endoprosthetics will have to focus on its efficacy in conjunction with sudden, strong demands, and long-term performance in bodily fluids within joint simulators, etc. In conclusion: C/SiC can definitely be considered a new material with genuine potential for use in endoprosthetics