The December 2024 Foot & Ankle Roundup. 360. looks at: Tibiotalar sector and lateral ankle instability; Isolated subtalar fusion and correction of progressive collapsing foot deformity; Diabetic control and postoperative complications following ankle fracture fixation; Are insoles of any benefit for plantar fasciitis?; Postoperative foot shape and patient-reported outcome following surgery for progressing collapsing foot deformity; Calcaneo-stop procedure for symptomatic flexible flatfoot in children

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.

Introduction. The arch of the foot has been described as a truss where the plantar fascia (PF) acts as the tensile element. Its role in maintaining the arch has likely been underestimated because it only rarely torn in patients with progressive collapsing foot deformity (PCFD). We hypothesized that elongation of the plantar fascia would be a necessary and sufficient precursor of arch collapse. Method. We used a validated finite element model of the foot reconstructed from CT scan of a female cadaver. Isolated and combined simulated ligament transection models were created for each combination of the ligaments. A collapsed foot model was created by simulated transection of all the arch supporting ligaments and unloading of the posterior tibial tendon. Foot alignment angles, changes in force and displacement within each of the ligaments were compared between the intact, isolated ligament transection, and complete collapse conditions. Result. Isolated release of the PF did not cause deformity, but lead to increased force in the long (142%) and short plantar (156%), deltoid (45%), and spring ligaments (60%). The PF was the structure most able to prevent arch collapse and played a secondary role in preventing hindfoot valgus and forefoot abduction deformities. Arch collapse was associated with substantial attenuation of the spring (strain= 41%) and interosseous talocalcaneal ligaments (strain= 27%), but only a small amount in the plantar fascia (strain= 10%). Conclusion. Isolated PF release did not cause arch collapse, but arch collapse could not occur without at least 10% elongation of the PF. Simulated transection of the PF led to substantial increase in the force in the other arch supporting ligaments, putting the foot at risk of arch collapse over time. Chronic degeneration of the PF leading to plantar fasciitis may be an early sign of impending PCFD

Aims

There is a lack of high-quality research investigating outcomes of Ponseti-treated idiopathic clubfeet and correlation with relapse. This study assessed clinical and quality of life (QoL) outcomes using a standardized core outcome set (COS), comparing children with and without relapse.

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

Introduction. Surgical reconstruction of Charcot joint deformity is increasingly being offered to patients. In our centre a hybrid type fixation technique is utilised: internal and external fixation. This combined fixation has better wound management and earlier mobilisation in this deconditioned patient group. The aim of this study was to assess clinical, radiological and patient reported outcomes for all patients who underwent this hybrid technique. Methods. This is a prospective observational case series of all patients who underwent surgical reconstruction of Charcot foot deformity in a single centre between June 2017 and June 2023. Patient demographics, smoking status, diabetic control and BMI were recorded. Outcomes were determined from case notes and included clinical outcomes (complications, return to theatre, amputation and mortality) radiological outcomes and patient reported outcomes. The follow up period was 1–7 years post operatively. Results. 42 reconstructions were included. At the time of surgery the mean age was 59.1 years (29 – 91 years), average HbA1c was 65.2 (33–103); this did not correlate with return to theatre rate. 4 procedures were internal fixation alone (9.5%), 3 external fixation alone (7.1%) and 35 were combined fixation (83.3%). At most recent follow up 7 patients were deceased (16.7%), 2 patients had ipsilateral amputations, 2 had contralateral amputations. 11 patients had issues with recurrent ulcerations. Excluding refreshing of frames and operations on the contralateral side, 17 patients (40%) returned to theatre. We aim to present a detailed analysis of the rate of post-operative complications, return to theatre, radiographic outcomes and patient reported outcomes. Conclusion. This is the largest UK based case series of hybrid type Charcot joint reconstructions and shows that hybrid fixation is a viable option for patients undergoing Charcot joint reconstruction. To best confirm findings and determine which patients have the best post-operative prognosis a larger multi-centre study is required

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

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

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. 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.

The April 2024 Foot & Ankle Roundup³⁶⁰ looks at: Safety of arthroscopy combined with radial extracorporeal shockwave therapy for osteochondritis of the talus; Bipolar allograft transplantation of the ankle; Identifying risk factors for osteonecrosis after talar fracture; Balancing act: immediate versus delayed weightbearing in ankle fracture recovery; Levelling the field: proximal supination osteotomy’s efficacy in severe and super-severe hallux valgus; Restoring balance: how adjusting the tibiotalar joint line influences movement after ankle surgery.

Aims

Posterior malleolar (PM) fractures are commonly associated with ankle fractures, pilon fractures, and to a lesser extent tibial shaft fractures. The tibialis posterior (TP) tendon entrapment is a rare complication associated with PM fractures. If undiagnosed, TP entrapment is associated with complications, ranging from reduced range of ankle movement to instability and pes planus deformities, which require further surgeries including radical treatments such as arthrodesis.

Aims

Children with spinal dysraphism can develop various musculoskeletal deformities, necessitating a range of orthopaedic interventions, causing significant morbidity, and making considerable demands on resources. This systematic review aimed to identify what outcome measures have been reported in the literature for children with spinal dysraphism who undergo orthopaedic interventions involving the lower limbs.

3D accurate measurements of the skeletal structures of the foot, in physiological and impaired subjects, are now possible using Cone-Beam CT (CBCT) under real-world loading conditions. In detail, this feature allows a more realistic representation of the relative bone-bone interactions of the foot as they occur under patient-specific body weight conditions. In this context, varus/valgus of the hindfoot under altered conditions or the thinning of plantar tissues that occurs with advancing age are among the most complex and interesting to represent, and numerous measurement proposals have been proposed. This study aims to analyze and compare these measurements from CBCT in weight-bearing scans in a clinical population. Sixteen feet of diabetic patients and ten feet with severe adult flatfoot acquired before/after corrective surgery underwent CBCT scans (Carestream, USA) while standing on the leg of interest. Corresponding 3D shapes of each bone of the shank and hindfoot were reconstructed (Materialise, Belgium). Six different techniques found in the literature were used to calculate the varus/valgus deformity, i.e., the inclination of the hindfoot in the frontal plane of the shank, and the distance between the ground and the metatarsal heads was calculated along with different solutions for the identification of possible calcifications. Starting with an accurate 3D reconstruction of the skeletal structures of the foot, a wide range of measurements representing the same angle of hindfoot alignment were found, some of them very different from each other. Interesting correlations were found between metatarsal height and subject age, significant in diabetic feet for the fourth and fifth metatarsal bones. Finally, CBCT allows 3D assessment of foot deformities under loaded conditions. The observed traditional measurement differences and new measurement solutions suggest that clinicians should consider carefully the anatomical and functional concepts underlying measurement techniques when drawing clinical and surgical conclusions

A medializing calcaneal osteotomy (MCO) is one of the key inframalleolar osteotomies to correct progressive collapsing foot deformity (PCFD). While many studies were able to determine the hind- and midfoot alignment after PCFD correction, the subtalar joint remained obscured by superposition on plain radiography. Therefore, we aimed to perform a 3D measurement assessment of the hind- and subtalar joint alignment pre- compared to post-operatively using weightbearing CT (WBCT) imaging. Fifteen patients with a mean age of 44,3 years (range 17-65yrs) were retrospectively analyzed in a pre-post study design. Inclusion criteria consisted of PCFD deformity correct by MCO and imaged by WBCT. Exclusion criteria were patients who had concomitant midfoot fusions or hindfoot coalitions. Image data were used to generate 3D models and compute the hindfoot - and talocalcaneal angle as well as distance maps. Pre-operative radiographic parameters of the hindfoot and subtalar joint alignment improved significantly relative to the post-operative position (HA, MA. Sa. , and MA. Co. ). The post-operative talus showed significant inversion, abduction, and dorsiflexion of the talus (2.79° ±1.72, 1.32° ±1.98, 2.11°±1.47) compared to the pre-operative position. The talus shifted significantly different from 0 in the posterior and superior direction (0.62mm ±0.52 and 0.35mm ±0.32). The distance between the talus and calcaneum at the sinus tarsi increased significantly (0.64mm ±0.44). This study found pre-dominantly changes in the sagittal, axial and coronal plane alignment of the subtalar joint, which corresponded to a decompression of the sinus tarsi. These findings demonstrate the amount of alternation in the subtalar joint alignment that can be expected after MCO. However, further studies are needed to determine at what stage a calcaneal lengthening osteotomy or corrective arthrodesis is indicated to obtain a higher degree of subtalar joint alignment correction

The December 2023 Children’s orthopaedics Roundup. 360. looks at: A comprehensive nonoperative treatment protocol for developmental dysplasia of the hip in infants; How common are refractures in childhood?; Femoral nailing for paediatric femoral shaft fracture in children aged eight to ten years; Who benefits from allowing the physis to grow in slipped capital femoral epiphysis?; Paediatric patients with an extremity bone tumour: a secondary analysis of the PARITY trial data; Split tibial tendon transfers in cerebral palsy equinovarus foot deformities; Liposomal bupivacaine nerve block: an answer to opioid use?; Correction with distal femoral transphyseal screws in hemiepiphysiodesis for coronal-plane knee deformity

Aims

The Ponseti method is the gold standard treatment for congenital talipes equinovarus (CTEV), with the British Consensus Statement providing a benchmark for standard of care. Meeting these standards and providing expert care while maintaining geographical accessibility can pose a service delivery challenge. A novel ‘Hub and Spoke’ Shared Care model was initiated to deliver Ponseti treatment for CTEV, while addressing standard of care and resource allocation. The aim of this study was to assess feasibility and outcomes of the corrective phase of Ponseti service delivery using this model.

Aims

Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity.

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.