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

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

Introduction: Adult acquired flatfoot is a common cause of foot pain. The majority of series describe surgery although important non-surgical series exist. This series of 166 patients gives an overview of the clinical spectrum of the condition and outcomes. Materials and Methods: Data was collected prospectively on 166 consecutive patients with adult acquired flatfoot between 1995 and 2005. 104 patients were reviewed at a median of eight years (range 3–13). A standardised clinical examination, AOFAS hindfoot and visual analogue satisfaction scores were performed. Results: There were 40 men (median age 56 years) and 126 women (median age 60 years). 68% had other musculoskeletal problems. Patients were Truro staged at presentation; Stage 1: 26 patients. Stage 2A: 84 patients. Stage 2B: 25 patients. Stage 2C: 23 patients. Stage 3: 6 patients. Stage 4: 2 patients. Stage 1 patients were younger (p< 0.001). 133 patients had soft-tissue symptoms, but 33 had degenerative problems. Degenerative patients had a higher median age (p=0.0138) and stiffer deformities (p< 0.0001). Most patients (131, 78.9%) were managed conservatively. Surgery was commoner in the arthritic group (p=0.001). Fifty-two conservatively treated feet were clinically reassessed. In 31 (59%) patients the Truro stage had not changed, 11 (21%) had improved and 10 (20%) had deteriorated. Twenty percent of patients treated with orthoses stopped using them after 18 to 24 months. In non-surgically treated patients, the median AOFAS score was 73/100 and satisfaction score 71/100. In surgically treated patients the median AOFAS score was 74/100 and satisfaction score 83/100. Discussion: There is a young group of patients with adult acquired flatfoot, with soft tissue symptoms but no progressive deformity. There is a large group with a flexible deformity who can mostly be treated with orthoses, and an older group with stiffer, arthritic deformities who are more likely to need surgery. Conclusion: Final outcomes and satisfaction were similar in surgically and non-surgically treated patients

Purpose of the study: When treating flatfoot, the objective of subtalar arthrodesis is to reestablish appropriate relations between the talus and the calcaeum by implanting a spacer. The purpose of this study was to evaluate the use of an expansion screw placed in the tarsal sinus and to assess the outcome. Material and methods: Thirty patients with reducible symptomatic flatfoot participated in the study. There were 28 men and 2 women. Surgery was proposed because of pain-related functional disability and failure of orthopedic treatment. Mean age at surgery was 21 years. The Djian-Annonier angle was 134°. The patients were reviewed retrospectively. The Kitaoka function score was noted. Results: Mean follow-up was four years. None of the patients wore orthopedic shoes. Degenerative joint remodeling was not observed. The overall outcome was: very good (n=20), good (n=4), fair (n=2), poor (n=4). Discussion: Arthrorisis using a spacer positioned in the tarsal sinus is a technically simple procedure enabling significant podoscopic correction of flatfoot which persists. Conclusion: This simple technique enables satisfactory anatomic and functional results

Introduction. Traditional treatment of idiopathic flatfoot in the adult population include calcaneal neck lengthening or fusions. These surgical methods result in abnormal function with significant complication rates. Our prospective study aimed to quantify the functional and radiological outcome of a new technique for spring ligament reconstruction using a hamstring graft, calcaneal osteotomy and medial head of gastrocnemius recession if appropriate. Methods. 22 feet were identified from the senior authors flatfoot reconstructions over a 3 year period (Jan 2013 to Dec 2015). 9 feet underwent a spring ligament reconstruction. The control group were 13 feet treated with standard tibialis posterior reconstruction surgery. Follow up ranged from 8 to 49 months. Functional assessment comprised VAS heath and pain scales, EQ-5D and MOXFQ scores. Radiographic analysis was performed for standardised parameters. Results. Each group contained two bilateral procedures. The spring ligament patients had a mean age of 43, BMI of 29 and a male to female ratio of 4;1 There were no statistical differences between groups starting point functional scores or pre-operative radiological deformity. Post-operatively there was a statistically significant improvement of all domains and overall MOXFQ, EQ5d and VAS in the spring ligament patients. There was a statistically significant improvement in all radiological parameters with all patients being returned to normal. Functional scores were not significantly better than the control group [MOXFQ components, Control vs spring ligament group, Pain: 42 vs 45 (p=0.71), Walking: 50 vs 56 (p=0.43), Social: 35 vs 39 (p=0.72), EQ-5D: 0.64 vs 0.70 (p=0.72)]. Spring ligament reconstruction produced statistically better deformity correction for 4 of 5 measured radiological parameters (p< 0.05). Conclusion. Our new method of spring ligament reconstruction restores normal anatomy. In comparison to traditional procedures our method provides equivalent functional results and improved deformity correction

Previous studies of adult acquired flatfoot have reported the results of treatment. No study has described the clinical characteristics of a consecutive series. In a ten-year period we managed 166 patients with adult acquired flatfoot. Forty were male and 126 female The median age of the men was 56 years and of the women 60 years (p=0.149). Twenty-eight had bilateral problems and 78% had gastrocnemius/soleus tightness. We used the Truro classification. There were 26 stage 1 patients, with a median age of 45 years. Eight were male and 18 female. Eight had features of enthesopathy but rheumatological investigations were negative. There were 84 stage 2 patients, with a median age of 61 years; 23 were male and 61 female. Twenty-five patients were stage 3, with a median age of 59 years; 5 were male and 20 female. 23 patients were in stage 4, with a median age of 67 years; 4 were male and 19 female. Six patients were stage 5, with a median age of 67.5 years; all were female. There were two patients in stage 6, aged 81 and 85 years, both female. The stage 1 patients were significantly younger than the others (p< 0.001); there were no other significant differences in ages or sex ratios. Most patients had predominantly soft-tissue problems. However, we identified 33 whose problems related mainly to osteoarthritis. These patients had a higher median age (62.5 years versus 58 years, p=0.0138) and stiffer deformities (p< 0.0001). Most patients (131, 78.9%) were managed solely with orthotics, shoe adaptations and physiotherapy. Thirty-five patients were offered surgery. Twenty-eight procedures were performed on 23 patients. Surgery was commoner in the arthritic group (15/33 offered surgery versus 20/133, p=0.001)

Introduction: Adolescent peroneal spastic flatfoot (PSF) is often regarded as synonymous with tarsal coalition. Inflammatory arthropathies, infections and tumours may, however, all present in this way, and in a few patients with PSF no definitive pathology may be identified. We aim of to evaluate the causes of adolescent PSF and to develop an an algorithm for its investigation and the management of those patients in whom no underlying pathology is identified. Methods: All adolescent patients presenting to the senior author with PSF over a two year period were evaluated first for tarsal coalition by means of clinical examination, plain x-rays and CT scanning. If this proved inconclusive an MRI scan was performed and bloods sent for inflammatory and infective markers. If these too identified no treatable cause the patients were treated with a manipulation under anaesthetic, injection of steroid and local anaesthetic into the subtalar joint and immobilization in a below knee cast for 4 weeks. They then received physiotherapy and a talar neutral orthosis. Follow-up was at 4 weeks post-injection and continued until symptoms resolved. Results: Five patients were found to have PSF with no identifiable cause. All were male, aged 12–17 at presentation. Four completed the treatment. Mean final follow-up was at 10 months post-procedure. All patients reported relief of pain following the procedure and returned to normal activity. At final follow-up, three were still participating in regular sport. One patient suffered a recurrence of his pain. Conclusion: Adolescent peroneal spastic flatfoot is often, but not always due to tarsal coalition. If this and other treatable causes have been excluded, treatment with the regime described may give good symptomatic relief in the short to medium term

Most of the controversy surrounding management of the adult acquired flatfoot deformity revolves around the correction of Stage 2 deformity. Stage 1 deformity, uncommonly corrected surgically, involves tenosynovitis with preservation of tendon length and absence of structural deformity. Attempts at tenosynovectomy in light of structural deformity leads to operative failure, found in 10% of Teasdall and Johnson's 1992 patient population. Thus, with tenosynovectomy rarely becoming an operative situation, Stage 2 deformity becomes the mainstay of operative treatment of the adult flatfoot. Stage 2 deformity patients present with swelling medially, the inability to do a single heel raise, with a passively correctable subtalar joint. The tendon is functionally torn. In recent years, authors have subdivided Stage 2 deformity even further into A and B subcategories, where A involves less than 50% uncovering of the talonavicular joint, and B patients more than 50%. Recently, Anderson has added a C subtype, which may be applied to either A and B patients, in patients who have forefoot varus. Thus, Stage 2 patients suffer from pain that begins medially and progresses to the subfibular region over time. Most important, recognition of the continued sub classification in Stage 2 disease echoes the fact that this disorder is on a continuum, challenging the surgeon to recognize subtleties that, if unrecognized, lead to a poor patient outcome. The mainstay of treatment in Stage 2 disease is the medial slide calcaneal osteotomy, which realigns the hindfoot axis reducing valgus, improves the medial arch, protects the FDL tendon transfer, and allows the Achilles tendon to become a strong inverter. Over shift of the calcaneus can compromise the outcome, as will a lack of recognition of the congenital subtleties such that a valgus hindfoot can have a varus orientation to the calcaneus, both leading to lateral overload. A pure medial slide of a calcaneus that has a varus orientation does not correct deformity, rather, it creates it. Thus, an axial calcaneal view must be studied carefully, for a varus orientation may be corrected via a closing wedge osteotomy commensurate with the medial shift of the tuberosity. As noted above, the flexor digitorum longus tendon transfer is the staple procedure to replace the damaged posterior tibial tendon. This transfer balances the eversion power of the peroneal tendons, works in phase with the former posterior tibial tendon in the stance phase of gait, and replaces a painful diseased posterior tibial tendon. However, over tensioning the transfer results in a tenodesis rather than a functional tendon transfer, the relative weakness of the FDL tendon (30% as strong as the PTT) creates difficulty with heel raise, and inappropriate transfer to distal tarsal bones may compromise the result by limiting torque from the transferred tendon. Preservation of the posterior tibial tendon in combination with the transferred FDL tendon remains a consideration without answer, though Rosenfeld (2005) suggests a substantial improvement in strength through PTT preservation. Failure of the above protocol for treating Stage 2 disease most often revolves around the insufficient corrective power of the tandem procedures in longstanding ruptures. According to Guyton (2001), only 50% of patients report a perception in deformity improvement following FDL/calcaneal osteotomy procedures, and only 4% report a significant improvement in pre-existing deformity. Sangeorzan (2001) found such patients could not achieve a painless plantigrade foot due to acquired ligament laxity (primarily the Spring Ligament). Sangeorzan applied Evans' pediatric procedure to adults without confirming the pathomechanics of correction. Some speculate the windlass effect on the plantar fascia creates correction (refuted by Horton, 1998, finding the plantar fascia is loosened by a lateral column lengthening), others believe tightening the peroneus longus through lateral column lengthening increases first ray plantarflexion, restoring the medial arch. Controversy also remains in answering Cooper's (1997) claim that lengthening through the calcaneus creates static increase in pressure about the calcaneocuboid joint (1.4mPa total) that may lead to an arthritic joint long term. Painful lateral overload following lateral column lengthening remains difficult problem to both prevent and correct. This last point leads to some focusing their efforts on restoration of the medial column. This group focuses on the “C” type deformity noted by Anderson, those with forefoot varus. It is known that the medial column is supported by the navicular, the cuneiforms, and the first, second, and third metatarsals. While a Cotton (opening wedge medial cuneiform) osteotomy, a first tarsometatarsal joint arthrodesis, or a metatarsal osteotomy has value, the surgeon must note that this only corrects the first ray. Complete correction of the medial column is best achieved through naviculocuneiform joint arthrodesis. Standing radiographs commonly reveal collapse at that level; however, surgeons are reticent to perform such fusions in light of the higher nonunion rate

Introduction:. The purpose of this study was to elucidate the specific radiographic effects that the Cotton osteotomy confers when used in combination with other reconstructive procedures in the management of the flexible flat foot deformity. Methods:. Between 2002–2013, 198 Cotton osteotomies were retrospectively identified following IRB approval. 131 were excluded on the basis of ipsilateral mid/hindfoot arthrodesis, inadequate radiographs or being less than 18yrs old at time of surgery. Parameters including the articular surface angles of the hindfoot/forefoot, Meary's angle and a newly defined Medial Arch Sag Angle (MASA) were recorded. A matched group of patients who did not undergo a Cotton osteotomy but who underwent similar hindfoot reconstructive procedures served as historic controls. Results:. 67 Cotton osteotomies in 59 patients with a mean age of 45 years (range, 18–80) were evaluated. Concomitant procedures included combinations of tibialis posterior tendon (PTT) reconstruction, Evans lateral column lengthening, medial displacement calcaneal osteotomy (MDCO). In all patients who underwent a Cotton osteotomy, there were statistically significant improvements in the articular surface angles along the medial side of the foot (p < 0.05). Improvement in arch height was also found to be statistically significant (p < 0.05). In comparison to matched controls, the Cotton osteotomy did not improve Meary's angle but provided an additional 11.21° of MASA correction (p < 0.05) when used in in conjunction with the Evans procedure and PTT reconstruction. A similar trend was seen with MDCO and PTT reconstruction. Discussion:. This study confirms the Cotton osteotomy is a powerful surgical adjunct in flatfoot reconstruction and quantifies the additional 11.21° of MASA correction it provides when the Cotton osteotomy is added to a calcaneal osteotomy and PTT reconstruction. This has relevance as an alternative for selection of a medial column stabilization procedure, which is joint sparing

Introduction. Medial calcaneal displacement osteotomy with an FDL tendon transfer is a common method of correcting pes planus deformity secondary to grade II tibialis posterior dysfunction. There is currently no evidence that calcaneal displacement alters the centre of pressure in the foot from a medial to a more central position as the normal shape is reconstituted. Materials and Methods. We prospectively evaluated 12 patients undergoing flatfoot reconstruction. Each patient had a preoperative AOFAS hindfoot score, pedobariographs and antero-posterior and lateral radiographs. This was repeated 6 months following surgery. Results. An angle (α) between the central axis of the foot (calcaneum to 2nd metatarsal head) and the centre of pressure (COP) was calculated for each patient both pre and post operatively and analysed using the Shapiro Wilk and the Students t test. Pressures directly under the 1st and 5th metatarsal heads and the calcaneum were also recorded and the pre and post operative differences analysed. The mean change in α angle is 6.1° (p < 0.01). The mean increase in pressure on the 1st metatarsal head is 460kPa (p = 0.08). The pressure changes on the 5th metatarsal head and the calcaneum are not statistically significant. The mean AOFAS score increases from 39.2 preoperatively to 82.8 postoperatively (p = 0.0019). The Meary angle improves from a mean of 12.7° to 5.7° (p = 0.027) and the calcaneal pitch improves from15.1° to 18.2° (p = 0.12). Conclusion. The medial displacement calcaneal osteotomy is able to significantly lateralise the centre of pressure in the foot and also increases the pressure under the 1st metatarsal head to more closely represent the parameters of the normal foot. The shape of the foot as judged radiographically and the clinical outcomes (AOFAS) are also improved

It is suggested that there is a link between overuse injuries and the type of arch of the foot, and that the use of appropriate running shoes may reduce running injuries substantially. However, to select the correct shoe, a runner needs knowledge of the anatomy and biomechanics of his/her foot. Five orthopaedic surgeons and experienced orthopaedic technicians examined the feet of 92 runners of mean age 35.4 years (12 to 63), mean height 176 cm (154 to 195) and mean body weight 70.38 kg (45 to 95). Weight-bearing podograms were used to define deformities of the feet further. A questionnaire ascertained what runners knew about their arch heights and the biomechanics of running. Of 43 volunteers with normal arches, 25 correctly assessed their feet, but only 18 of 47 runners with a flatfoot deformity identified their deformity. Two runners with a cavus foot identified it correctly. Only four of 38 runners who diagnosed themselves as pronators were found to be, and four runners who self-diagnosed non-pronation were classified as pronators. Three runners who could not classify themselves were diagnosed as pronators. This study demonstrates the poor knowledge of foot deformities in the running community

It is suggested that there is a link between arch type of the foot and overuse injuries. The use of individual selected running shoes can reduce running injuries substantially. To select the correct shoe the runner needs to have appropriate knowledge of his own foot anatomy and biomechanics. A questionnaire was used to investigate the knowledge of the runner about his arch height and biomechanics of running. Clinical examination was performed by 5 orthopaedic surgeons and experienced orthopaedic technicians. Weight-bearing podograms were used to further define the deformity. We examined 92 volunteers with a mean age of 35.4 (12–63) years, a mean size of 176 cm (154–195) with a mean body weight of 70.38 kg (45–95). Eighteen out of 47 runners with a flatfoot deformity identified their deformity correctly. Twenty five out of 43 volunteers with a normal arch were correct in assessing their foot. Two runners with a cavus foot were correct in identifying their foot. Only 4 out of 38 runners that diagnosed themselves as being pronators have been found to be pronators. Four runners with a self-diagnosed non-pro-nating foot were classified as being pronators. Three runners that could not classify themselves were diagnosed as pronators. This study demonstrates the poor knowledge of foot deformities in the running community

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.

Purpose

Flat feet are an important cause of foot problems in children. The flexible flat foot is the most common form and is normally physiological and asymptomatic. Further assessment is necessary when a symptomatic flat foot persists. Surgical interventions are indicated when conservative therapies have failed. The Kalix arthroereisis is a surgical option and is placed in the subtalar joint of the foot, thereby preventing hyperpronation, and stabilizes the foot against excessive movements. The purpose of this study was to evaluate the functional and radiological outcomes of pediatric patients who had undergone a Kalix implantation for the treatment of a symptomatic flexible flat foot.

Objective

To assess the usefulness of radiographs alone to evaluate acute midfoot/forefoot injuries. We believe that foot injuries are often under-estimated and that CT scans should be routinely obtained to aid in their management and avoid additional morbidity for patients.

Background: A novel method for harvesting the flexor digitorum longus (FDL) tendon has previously been described via a plantar approach based on a surface coordinate. The aim of this investigation is to provide a comparison with the traditional medial midfoot dissection for tendon harvest.

Methods: The FDL tendon was exposed in 10 cadaveric feet via a limited plantar approach and also medially as far as could be accessed via the knot of Henry. The FDL was marked with a metal clip in each approach. The lengths of the skin incisions were recorded and the distance between the two markers was measured. The morphology of the FDL tendon was observed including interconnections with the flexor hallucis longus (FHL) tendon.

Results: The mean additional length of tendon accessed via the plantar approach was 22.9 mm with a mean reduction in skin incision length of 15.6 mm. The FDL tendon showed some division at the site of the plantar exposure and there were FDL - FHL interconnections in nine of the feet with three distinct patterns observed.

Conclusion: Using the plantar exposure, a longer length of tendon can be obtained through a smaller skin incision, which has been quantified here. Observations on FDL tendon morphology and interconnections may have clinical significance.

The significance of flat-foot in childhood and adolescence in Italy has never been studied on a statistically significant sample.

In our survey, thousands of subjects from different regions of northern, central and southern Italy (Calabria, Lazio, Umbria, Lombardia) were studied in order to determine the prevalence of flat-foot and search for possible genetic or environmental factors that may influence the normal development of the longitudinal arch, starting from birth.

Materials and methods: In order to obtain the footprints of children (aged 6–11, attending primary school), we used a polarized light podoscope; we used this instrument, instead of more advanced ones such as baropodometric platforms, because flat-foot diagnosis is basically static and also because the majority of existing studies use the same methodology and have established simple, reliable and reproducible diagnostic criteria, making a more accurate data comparison possible.

Podoscopy was integrated with anamnesis, physical examination and measurement of weight and height. Footprint morphology has been related with variables such as age, sex, geographical area of origin and BMI (Body Mass Index).

Progressive collapsing foot deformity (PCFD) is a common condition with an estimated prevalence of 3.3% in women greater than 40 years. Progressive in nature, symptomatic flatfoot deformity can be a debilitating condition due to pain and limited physical function; it has been shown to have one of the poorest preoperative patient reported outcome scores in foot and ankle pathologies, second to ankle arthritis. Operative reconstruction of PCFD can be performed in a single-stage manner or through multiple stages. The purpose of this study is to compare costs for non-staged (NS) flatfoot reconstructions, which typically require longer hospital stays, with costs for staged (S) reconstructions, where patients usually do not require hospital admission. To our knowledge, the comparison between single-staged and multi-staged flatfoot reconstructions has not been previously done. This study will run in conjunction with one that compares rates of complications and reoperation, as well as patient reported outcomes on function and pain associated with S and NS flatfoot reconstruction. Overall, the goal is to optimize surgical management of PCFD, by addressing healthcare costs and patient outcomes. At our academic centre with foot and ankle specialists, we selected one surgeon who primarily performs NS flatfoot reconstruction and another who primarily performs S procedures. Retrospective chart reviews of patients who have undergone either S or NS flatfoot reconstruction were performed from November 2011 to August 2021. Length of operating time, number of primary surgeries, length of hospital admission, and number of reoperations were recorded. Cost analysis was performed using local health authority patient rates for non residents as a proxy for health system costs. Rates of operating room per hour and hospital ward stay per diem in Canadian dollars were used. The analysis is currently ongoing. 72 feet from 66 patients were analyzed in the S group while 78 feet from 70 patients were analyzed in the NS group. The average age in the S and NS group are 49.64 +/− 1.76 and 57.23 +/− 1.68 years, respectively. The percentage of female patients in the S and NS group are 63.89% and 57.69%, respectively. All NS patients stayed in hospital post-operatively and the average length of stay for NS patients is 3.65 +/− 0.37 days. Only 10 patients from S group required hospital admission. The average total operating room cost including all stages for S patients was $12,303.12 +/− $582.20. When including in-patient ward costs for patients who required admission from S group, the average cost for operating room and in-patient ward admission was $14,196.00 +/− $1,070.01 after flatfoot reconstruction. The average in-patient ward admission cost for NS patients was $14,518.83 +/− $1,476.94 after flatfoot reconstruction. The cost analysis for total operating room costs for NS patients are currently ongoing. Statistical analysis comparing S to NS flatfoot reconstruction costs are pending. Preliminary cost analysis suggests that multi-staged flatfoot reconstruction costs less than single-staged flatfoot reconstruction. Once full assessment is complete with statistical analysis, correlation with patient reported outcomes and complication rate can guide future PCFD surgical management

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

Applications of weightbearing computed tomography (WBCT) imaging in the foot and ankle have emerged over the past decade. However, the potential diagnostic benefits are scattered across the literature, and a concise overview is currently lacking. Therefore, we aimed to systematically review all reported diagnostic applications per anatomical region in the foot and ankle. A systematic literature search was performed in the electronic databases PubMed, EMBASE, Cochrane Library, and Web of Science. Search terms consisted of “weightbearing/standing CT and ankle, hind-, mid- or forefoot”. English language studies analyzing the diagnostic applications of WBCT were included. Studies were excluded if they simulated weightbearing CT, described normal subjects, included cadaveric samples or samples were case reports. The modified Methodological Index for Non-Randomized Studies (MINORS) was applied for quality assessment. The added value was defined as the review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the Prospero database (CRD42019106980). A total of 48 studies (prospective N=8, retrospective N=36, cohort study N=1, diagnostic N=2, prognostic comparative study N=1) were found to be eligible for review. The following diagnostic applications were identified per anatomical area in the foot: ankle (osteoarthritis N=5, ligament injury N=6); hindfoot (deformity N=9); midfoot (Lisfranc injury N=2, flatfoot deformity N=13, osteoarthritis N=1); forefoot (hallux valgus N=12). The identified studies contained diagnostic applications that could not be used on plain radiographs. The mean MINORS equaled 10.1 on a total of 16 (range: 8 to 12). Diagnostic applications of weightbearing CT imaging are most frequently studied in hindfoot deformity, but other area's areas are on the rise. Post-processing of images was identified as the main added value compared to WBRX. However, the findings should be interpreted with caution as the average quality score was moderate. Therefore, future prospective studies are warranted to consolidate the role of WBCT in diagnostic and therapeutic algorithms