INTRODUCTION:Osteochondral defects (OCDs) of the talus are a "TOP 10" research priority in foot and ankle surgery, identified by the James Lind Alliance in partnership with BOFAS, BOA and NIHR. To inform a research strategy, the treatment preferences of BOFAS members were surveyed. METHODS:A questionnaire on the presentation, investigation and management of primary OCDs of the talus that had failed non-surgical treatment was formulated by the BOFAS National Clinical Study Group, ratified by the Scientific Committee, and distributed via Microsoft Forms. Surgical treatment was categorised by defect size (small: ≤15 mm; large: >15 mm) and depth (shallow: ≤5 mm; deep: >5 mm), with depth defined as the cranio-caudal dimension into subchondral bone on MRI. RESULTS:There were 90 responses (90/224; 40.2% response rate). Bone marrow stimulation (BMS; microfracture or nanofracture) was the dominant first-line choice across all categories. For small, shallow lesions, 85/90 respondents (94%) chose BMS. For large, shallow lesions, BMS was chosen by 59 (68%), BMS plus a scaffold (AMIC/ACIC) by 18 (21%), and BMS plus a biological agent (cBMA/PRP) by 6 (7%). For small, deep lesions, BMS remained most popular (69 respondents; 77%). For large, deep lesions, BMS was chosen by 43 (49%), BMS plus scaffold by 23 (26%), and osteochondral autograft transfer (OATS) by 7 (8%). Post-operative weight-bearing preferences varied considerably, with 49% allowing immediate unrestricted weight-bearing. DISCUSSION:This is the largest national BOFAS survey on OLT management to date in the United Kingdom. BMS was the most popular treatment across all lesion types, consistent with Guelfi et al. (2021). However, significant practice variation exists, particularly for larger and deeper lesions. High-quality randomised controlled trials are needed to establish optimal evidence-based treatment for OLTs.

Background Extra-corporeal shockwave therapy (ESWT) is commonly used for plantar fasciitis (PF). Calcaneal spurs have up to 80% prevalence in PF. The objective was to assess whether calcaneal spurs with associated oedema affect the outcomes of ESWT. Methods Single-centre study of 30 patients over 3-years. Patients with confirmed diagnoses of PF on MRI scan who underwent ESWT were included. Patient reported outcomes scores (EQ5D / MOxFQ) were recorded pre-treatment and at 1-year post-ESWT. Results Significant improvement (p<0.001) in MOxFQ score and subjective improvement with ESWT in all patients. No difference in improvement of MOxFQ / EQ5D in patients with calcaneal spurs compared to without (p>0.05). No correlation between presence of calcaneal spur oedema or spur size, and outcome scores (p>0.05). Conclusions In this cohort, neither spur presence nor peri-spur oedema was associated with a significantly different response to ESWT. The majority of patients reported symptomatic improvement following ESWT (63.3%) and the.mean MOxFQ Index improvement across the cohort exceeded the published minimum clinically important difference. Level of Evidence Level III, retrospective cohort study.

BackgroundThe distal metatarsal articular angle (DMAA) is a measurement used in surgical decision making of hallux valgus correction. However, it is difficult to measure on plain radiographs, is subject to projection bias, and its role in pathology is unclear. With the advent of weight-bearing CT (WBCT), our understanding of hallux valgus as a multiplanar deformity has evolved. The aim of this study was to investigate whether there is a relationship between the DMAA and pronation of the first metatarsal head in patients with hallux valgus.MethodsThis was a single-centre, retrospective analysis of 50 patients with hallux valgus deformity who had WBCTs obtained as part of routine pre-operative work-up. Patients with metatarsophalangeal joint arthritis, hindfoot deformity, and previous surgery were excluded. From the WBCT images, digital radiographs were created and the DMAA measured. Measurements were taken by 2 authors, each repeated twice and the average of all 4 measurements used in analysis. We also measured intermetatarsal angle (IMA), hallux valgus angle (HVA), and metatarsal pronation angle (MPA).ResultsThere were 41 females and 9 males, with a mean age of 52.4 ± 15.8 years. The IMA was 14.5 ± 3.3 degrees, HVA was 29.3 ± 8.4 degrees, MPA was 11.7 ± 6.3 degrees, and DMAA was 15.5 ± 5.3 degrees. Intraclass correlation coefficient (ICC) for intra-observer reliability was 0.829 for assessor 1 and 0.910 for assessor 2. ICC for inter-observer reliability was 0.727. Pearson correlation revealed no link between IMA and DMAA, nor HVA and DMAA. However, there was a significant (albeit small) correlation between MPA and DMAA (r = 0.337, P = .017). In the mixed effects model, MPA remained an independent predictor of DMAA (β = 0.276, 95% CI 0.153-0.399, P < .001).ConclusionThere was reasonable reliability in measuring DMAA between authors on WBCT although there was variation in measurements. We found the DMAA appeared to increase with increasing metatarsal pronation. The DMAA may therefore be (in part) projection artefact secondary to metatarsal pronation, and surgeons should be aware of this during surgical planning.

INTRODUCTION:Sagittal- and axial-plane lesser-toe deformities may be associated with plantar-plate attenuation, scarring, or rupture - limiting the feasibility of direct repair. Conventional options include osseous decompression, plantar-plate repair and flexor-to-extensor transfer. This technical tip describes a suture-based flexor digitorum longus (FDL) tenodesis to the proximal phalanx as an alternative for selected deformities. TECHNIQUE:Two operative approaches are presented. For deformity centred at the metatarsophalangeal (MTP) joint with preserved interphalangeal joints, the FDL is accessed through a dorsal approach following a Weil osteotomy and sutured to the proximal phalanx via a tunnel drilled through the base of the phalanx. Tendon position and suture tension are adjusted to provide dorsiflexion restraint and axial correction. Where concomitant proximal interphalangeal (PIP) joint fusion is required in a primarily sagittal plane deformity, the FDL may be accessed through the PIP joint, and sutures passed along either side of the proximal phalanx and tensioned after fusion. RESULTS:We have used this technique to provide dynamic stabilisation of the MTPJ. Asymmetric tendon positioning or tensioning can also generate an axial corrective moment. Established procedures remain appropriate, but this technique may have a role in selected patients. CONCLUSION:FDL tenodesis offers a suture-based option for multiplanar lesser-toe deformities as an alternative to plantar-plate repair. Its role may be considered within an individualised reconstructive strategy, with further clinical studies warranted to clarify its long-term comparative performance.

Aims First metatarsal Pronation is increasingly recognised as an important component of Hallux valgus (HV) and can contribute towards intraoperative malreduction, postoperative recurrence and patient reported outcome measures (1,2,3). There are numerous radiological ways to measure metatarsal rotation on plain radiographs and weight bearing CT (WBCT), however there are no clinical tests to evaluate metatarsal pronation pre- or intra-operatively. This study therefore aimed to examine the relationship between clinical pronation of the toe and metatarsal pronation. Methods Single-centre, retrospective analysis over 5 years. Measurements were performed on WBCT images with digital reconstructions to add soft tissues. First metatarsal rotation was measured using the Metatarsal Pronation Angle as previously described (4). Toe rotation was measured by the Phalangeal Condylar Angle (PCA), the angle between the condyles of the proximal phalanx and the floor, and the Nail Plate Angle (NPA), the angle of the base of the nail plate to the floor in the coronal Plane. These were obtained from 50 feet in Hallux valgus patients, and 50 control patients with CTs done for osteochondral lesions without hallux valgus or hindfoot malalignment. Results The HV group comprised 41 women and 9 men, mean age 52.4. Control group, 23 women and 23 male, mean age 40.25. Inter and Intra Observer reliability both excellent (ICC >0.95) for all measurements. When comparing HV vs control, MPA was 11.7 vs 6.0 (p<0.001), PCA 31.8 vs 4.7 (p<0.001), NPA 18.3 vs 6.0 (p<0.0001). NPA correlated with PCA. NPA and PCA correlate with Hallux valgus Angle (p<0.001), but not with MPA (p 0.567). Conclusion These results suggest that clinical toe pronation increases as HV angle increases but not with metatarsal pronation, which therefore cannot be used as a clinical marker. Toe pronation is similar at the base and at the nail, suggesting rotation happens at the MTPJ.

BACKGROUND:Ankle and hindfoot fusion in the presence of large bony defects represents a challenging problem. The purpose of this study was to evaluate outcomes of patients who underwent ankle-hindfoot fusions with impaction bone grafting (IBG) with morselized femoral head allograft to fill large bony void defects. METHODS:This was a 3-center, retrospective review of a consecutive series of 49 patients undergoing ankle or hindfoot fusions with femoral head IBG for filling large bony defects. Union was assessed clinically and radiologically with radiography or computed tomography. Graft stability/collapse was identified on radiographs as loss of graft height across the fusion interface. Indications included 35 failed total ankle arthroplasty, talar osteonecrosis and collapse (7 patients), failed ankle fusion (4 patients), trauma with bone loss or fracture nonunion (1 patients), and other (2 patients). Tibiotalocalcaneal (TTC) fusion was performed in 36 (73%) patients and ankle (TT) fusion in 13 (27%). RESULTS:Mean age was 59.3 (19-78) years. Mean follow-up was 22.9 ± 8.3 months. Eighteen percent were smokers. Mean depth of the bone defect was 35.2 ±8.7 mm, and mean volume of the defect was 62.2 ±5.8 cm3. Symptomatic nonunion rate was 14% (7/49). The mean time to radiologic union was 7.6 ±3.2 months. Complete radiologic union rate occurred in 73% (36/49). Eight TTC fusion patients (22.2%) united at the tibiotalar joint but not at the subtalar joint, of which 6 were asymptomatic. There was no graft collapse, even in patients developing nonunion, with all patients maintaining bone incorporation and leg length. CONCLUSION:Impaction of morselized femoral head allograft can fill large bony voids around the ankle or hindfoot during fusion, with rapid graft incorporation and no graft collapse despite early loading. This technique offers satisfactory and comparable union outcomes without limb shortening or expensive custom 3D-printed metal cages.

AimsThe adult cavus foot represents a challenging clinical problem, with varied aetiology and complex, 3-dimensional deformities. Thus far, the cavus foot has eluded a unified classification. The aim of this paper was to appraise the literature to identify classification systems which guide the operative management of neurological cavus feet in adults.MethodsAs the aim of this paper was broad, a scoping review was conducted. The review was conducted in line with published frameworks. Our principal research question was ‘what classification systems that guide surgical management currently exist for neurological cavus feet in adults’. We searched CINAHL, Embase, OVID, Proquest, Pubmed, Scopus and Web of Science databases using MESH and non-MESH terms. Two authors independently reviewed abstracts / papers and a data extraction sheet was used to collect the relevant data.ResultsA total of 1,140 articles were initially screened, identifying 125 articles for which a full text review was performed. Only three articles met all our inclusion criteria. All these articles reported an anatomical classification with suggestions for treatment based on the classification. All were considered to comprise Level V evidence, and none reported outcomes of treatment based on the classification.ConclusionsThere is currently a paucity of robust classifications to guide treatment in neurological cavus feet in adults. The few classifications systems that exist are varied and do not as yet have sufficient evidence to support their widespread use. Further work is required, aimed at identifying specific features of cavus feet that would guide operative treatment.

BACKGROUND:Recurrence after surgical correction of hallux valgus may be related to coronal rotation of the first metatarsal. The scarf osteotomy is a commonly used procedure for correcting hallux valgus but has limited ability to correct rotation. Using weight-bearing computed tomography (WBCT), we aimed to measure the coronal rotation of the first metatarsal before and after a scarf osteotomy, and correlate these to clinical outcome scores. METHODS:We retrospectively analyzed 16 feet (15 patients) who had a WBCT before and after scarf osteotomy for hallux valgus correction. On both scans, hallux valgus angle (HVA), intermetatarsal angle (IMA), and anteroposterior/lateral talus-first metatarsal angle were measured using digitally reconstructed radiographs. Metatarsal pronation angle (MPA), alpha angle, sesamoid rotation angle, and sesamoid position were measured on standardized coronal WBCT slices. Preoperative and postoperative (12 mo) clinical outcome scores (Manchester Oxford Foot Questionnaire and Visual Analogue Scores) were captured. RESULTS:Mean HVA was 28.6 ± 10.1° preoperatively and 12.1 ± 7.7° postoperatively (P < .001). Mean IMA was 13.7 ± 3.8° preoperatively and 7.5 ± 3.0° postoperatively (P < .001). Before and after surgery, there were no significant differences in MPA (11.4 ± 7.7 and 11.4 ± 9.9°, respectively; P = .75) or alpha angle (10.9 ± 8.0 and 10.7 ± 13.1°, respectively; P = .83). There were significant improvements in sesamoid rotation angle (SRA) (26.4 ± 10.2 and 15.7 ± 10.2°, respectively; P = .03) and sesamoid position (1.4 ± 1.0 and 0.6 ± 0.6, respectively; P = .04) after a scarf osteotomy. There were significant improvements in all outcome scores after surgery. Poorer outcome scores correlated with greater postoperative MPA and alpha angles (r = .76 (P = .02) and .67 (P = .03), respectively). CONCLUSION:A scarf osteotomy does not correct first metatarsal coronal rotation, and worse outcomes are linked to greater postoperative metatarsal rotation. Rotation of the metatarsal needs to be measured and considered when planning hallux valgus surgery. Further work was needed to compare postoperative outcomes with rotational osteotomies and modified Lapidus procedures when addressing rotation.Level of Evidence: 4.

INTRODUCTION:There is little information on the value of using single photon emission computerized tomography-computed tomography (SPECT-CT) in non-arthritic and non-neoplastic conditions of the foot and ankle (F&A). The vast majority of studies have investigated the role of SPECT-CT in degenerative conditions, bony pathology, and neoplastic conditions. The diagnostic value of SPECT-CT in purely non-arthritic and non-neoplastic conditions, in the absence of other conclusive radiological findings, is yet to be clarified. The aim of this study was to evaluate the value of SPECT-CT in a cohort of patients with complex F&A pathology, in whom diagnostic uncertainty existed after conventional imaging techniques, and to assess its added value in routine clinical practice. METHODOLOGY:A retrospective analysis of 297 SPECT-CTs from 2010 to 2017 found 18 SPECT-CTs (age = 16-56 years) performed for non-arthritic F&A pathology. Changes in diagnosis, management, and clinical outcome scores were recorded before and after SPECT-CT imaging. RESULTS:The results demonstrated that the provisional diagnosis was different from the SPECT-CT diagnosis in 10 (56%) out of the 18 patients and led to a modified treatment plan, which was successful in 8 (80%) out of the 10 patients. The post-intervention Manchester Oxford Foot Questionnaire (MOX-FQ) and Visual Analogue Scale (VAS) score improved from 76 ± 18 to 58 ± 24 (P = .02), and from 72 ± 17 to 49 ± 32 (P = .01), respectively. The SPECT-CT scan was useful in confirming the provisional diagnosis in the remaining 8 patients where a diagnostic uncertainty existed after conventional imaging techniques. Overall, a total of 15 out of 18 patients (83%) showed an improvement in their symptoms after management led by SPECT-CT diagnosis. CONCLUSION:Our study highlights the added value of SPECT-CT in patients presenting with non-arthritic and non-neoplastic F&A conditions in which there is diagnostic uncertainty after conventional imaging. In 80% of cases, a change in management driven by the SPECT-CT findings led to a successful outcome. We have found SPECT-CT to be a useful investigative modality in assessing these complex F&A cases. LEVELS OF EVIDENCE:Level IV.

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: Adults presenting with symptomatic clubfoot represent a challenging cohort of patients. An appreciation of the location and degree of deformities is essential for management. Talar anatomy is often abnormal with varus within the talar neck, however, there are few reproducible methods which quantify talar neck deformity in adults. We describe a technique of assessing talar neck deformity, and report on observed values and intra- / inter-observer reliability. Methods: This was a single-centre, retrospective study including 96 feet from 56 adult patients with clubfeet (82 feet had clubfoot deformity, 14 were normal). Mean age was 34.3±16.9 years and 31 (55.3%) were male. Weight-bearing CT scans captured as part of routine clinical care were analysed. Image reformats were oriented parallel to the long axis of the talus in the sagittal plane. In the corresponding axial plane two lines were drawn (on separate slices): 1) a line perpendicular to the intermalleolar axis, 2) a line connecting the midpoints of the talar head and narrowest part of the talar neck. The talar neck rotation angle (TNR angle) was the angle formed between these lines. Intraclass correlation coefficients (ICC) were performed for intra- and inter-observer reliability. Results: Mean TNR angle in clubfeet was 27.6±12.2 degrees (95%CI = 25.0 to 30.2 degrees). Mean TNR angle in normal feet was 18.7±5.1 degrees (95%CI = 16.0 to 21.4 degrees) (p < 0.001). The ICC for clubfeet was 0.944 (95%CI = 0.913 to 0.964) for intra- observer agreement, and 0.896 (95%CI = 0.837 to 0.932) for inter-observer agreement. Conclusion: This measurement technique demonstrated excellent intra- and inter-observer agreement. It also demonstrated that compared to normal feet, clubfeet had about 9 degrees of increased varus angulation of the talar neck. This technique and data may be used for future research into clubfoot deformity and in planning treatment.

Background: The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to analyze the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction. Methods: We included 20 cavovarus feet from 16 adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, range: 22-78 years, 14 males). Patients included had flexible deformities, with no previous surgery. Using specialized software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using morphologic data captured from normal feet in patients without pathology as a guide, the talonavicular joint of the cavovarus foot was digitally reduced to a “normal” position to simulate the correction that would be achieved during surgical correction. Models of the corrected position were exported and geometrically analyzed using Blender 3.64 to identify anatomical trends. Results: We identified 4 types of cavovarus forefoot morphotypes. Type 0 was defined as a balanced forefoot (2 cases, 10%). Type 1 was defined as a forefoot where the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular joint correction (12 cases, 60%). Type 2 was defined as a forefoot where the second and first metatarsals were progressively plantarflexed, with no significant adduction (4 cases, 20%). Type 3 was defined as a forefoot where the metatarsals were adducted after talonavicular derotation (2 cases, 10%). Conclusion: In this relatively small cohort, we identified 4 forefoot morphotypes in cavovarus feet that might help surgeons to recognize and anticipate the residual forefoot deformities after hindfoot correction. Different treatment strategies may be required for different morphotypes to achieve balanced correction. Level of Evidence: Level IV, retrospective case series.

Background: Tenosynovial giant cell tumor (TGCT) is a benign proliferative disease affecting synovial membranes. There are 2 forms, localized (L-TGCT) and diffuse (D-TGCT), which although histologically similar behave differently. It is locally invasive and is treated in most cases by operative excision. The aim of this study was to assess current practice, how the patients' presentation affected their outcome, as well as review the recurrence rates and complications.Methods: A retrospective analysis of 123 cases was performed in patients treated between 2003 and 2019 with TGCT of the foot and/or ankle. Data were collected on age at presentation, radiologic pattern of disease, location of disease, treatment provided, and recurrence rates. The minimum follow-up was 2 years with a mean of 7.7 years.Results: There were 61.7% female patients with a mean age of 39 (range, 11-76) years. L-TGCT accounted for 85 (69.1%) cases and D-TGCT for 38 (30.9%). The most prevalent preoperative symptoms were a palpable mass (78/123) and pain (65/123). Radiologically confirmed recurrence in the operative group was noted in 14.5% (16/110) cases. This comprised 4% (3/75) of operatively treated L-TGCT and 37% (13/35) of operatively treated D-TGCT. Patients with pain on presentation and those with erosive changes on presenting magnetic resonance imaging (MRI) were more likely to have persistent postoperative pain (P < .001 for both). Where patients had both preoperative pain and erosive changes, 57.1% had postoperative pain. Thirteen cases were managed nonoperatively where symptoms were minimal, with 1 case requiring surgery at a later date.Conclusion: Outcomes of TGCT management are dependent on the disease type, extent of preoperative erosive changes, and presence of preoperative pain. These data are useful for counseling patients regarding the outcomes of surgical intervention and help guide the timing of intervention.Level of Evidence: Level III, retrospective cohort study.

Background: This study assesses the coronal-plane deformities in cavovarus feet secondary to Charcot-Marie-Tooth disease (CMT) using Weightbearing-CT (WBCT) and semi-automated 3D-segmentation soft-ware.Methods: WBCTs from 30 CMT-cavovarus feet were matched to 30 controls and analysed using semi-au-tomatic 3D-segmentation (Bonelogic, DISIOR). The software used automated cross-section sampling with subsequent straight-line representation of weighted centre points to calculate 3D axes of bones in the hindfoot, midfoot and forefoot. Coronal relationships of these axes were analysed. Supination/pronation of the bones in relation to the ground and within each joint were measured and reported.Results: The most significant deformity in CMT-cavovarus feet occurred at the talonavicular joint (TNJ) with 23 degrees more supination than normal feet (6.4 +/- 14.5 versus 29.4 +/- 7.0 degrees, p < 0.001). This was countered by relative pronation at the naviculo-cuneiform joints (NCJ) of 7.0 degrees (-36.0 +/- 6.6 versus -43.0 +/- 5.3 degrees, p < 0.001). Combined hindfoot varus and TNJ supination resulted in an additive supination effect not compensated by NCJ pronation. The cuneiforms in CMT-cavovarus feet were therefore supinated by 19.8 degrees to the ground relative to normal feet (36.0 +/- 12.1 versus 16.2 +/- 6.8 degrees, p < 0.001). The forefoot-arch and 1st metatarsal-ground angles demonstrated similar supination to the cuneiforms suggesting no further significant rotation occurred distally.Conclusion: Our results demonstrate coronal plane deformity occurs at multiple levels in CMT-cavovarus feet. Majority of the supination arises at the TNJ, and this is partially countered by pronation distally, mainly at the NCJ. An understanding of the location of coronal deformities may help when planning surgical correction.

Category: Other Introduction/Purpose: With diagnostic resources often in great demand, it is important to ensure clinicians request investigations appropriately. Unnecessary radiological investigations are costly and delay patient care. This study aimed to assess the incidence and appropriateness of repeat MRI scans being requested in a single foot and ankle unit, to identify areas which can be improved. Methods: This was a retrospective analysis of 1322 scans between October-2019 to October-2022. We included all patients who had a diagnostic MRI scan requested after being assessed in our foot-and-ankle clinics. Assessments were made on the proportion of repeat scans, the seniority of requester, the indications put forward for the repeat scan, the modality of patient assessment (telephone vs face-to-face appointment), and the impact on patient management. A scan was considered a repeat, if the same anatomical location was scanned within a 3-year period. Scans were deemed appropriate if they were: part of a clinical trial, for tumour/infection/stress-fracture monitoring, for new trauma, pre-operative planning, following agreement in MDT discussions, or following significant changes in clinical symptoms. We expected that scans should ideally only be requested where the result is expected to influence management and that a scan should not be repeated without evidence of change in clinical symptoms (unless for monitoring). Results: Over the 3-year period, 6.5% of MRI scans performed were considered repeat scans. The average time between initial and repeat scans was 13.1±8.6months (range 1-33 months). 88% of patients had only one repeat scan. The majority(58%) of repeat scans were requested by non-senior clinicians. In total, 47/85(55%) scans were deemed appropriate. 75% of the patients in this cohort had been assessed face-to-face. Twenty of these scans were repeated for significant change in clinical symptoms and 50% meaningfully influenced management plans. Conversely, 38/85(45%) repeat scans did not have strong clinical indications. The majority(80%) of these were requested by non- senior clinicians and 50% were requested after a telephone review. From the scans requested by the non-senior clinicians, none(0%) had a meaningfully influence on patients’ management plans. Conclusion: This study highlights that although repeat MRI scans were not common, they seldom influenced patient management unless there was a meaningful change in patient symptoms. MRI scans were more likely to influence management when initiated by senior clinicians and following a face-to-face assessment. In order to streamline patient care and reduce unnecessary investigations we propose a protocol to guide the requesting of repeat scans. This protocol includes identifying significant symptomatic change, in-person review, and senior clinician or multi-disciplinary input when a repeat scan is being considered.

Category: Ankle; Basic Sciences/Biologics Introduction/Purpose: Osteochondral lesions of the talus (OLTs) present a challenging clinical problem. Hyaluronic acid assisted autologous membrane-induced chondrogenesis (H-AMIC) is a technique where a polyglycolic acid and hyaluronin membrane scaffold (Chondrotissue ® ) is affixed over an area of talar bone marrow stimulation. Our study aims to assess the efficacy of this technique. Methods: We undertook a prospective study on consecutive adult patients at our unit who had H-AMIC procedures between January 2020 and November 2021 to treat single, symptomatic OLTs, >1.5cm 2 , refractory to previous management. Data was collected on patient reported outcomes (MOxFQ, EQ5D, satisfaction), ankle range of movement, and complications at 1-year post-surgery. Fifteen patients were included in this study with a mean age of 33.8±20.9 years. Mean duration of symptoms was 7.9±5.2 years, with a mean of 1.5 previous procedures (range 0 to 3). All patients had osteotomies to gain access to the OLT (13 medial malleolar, 2 fibular). Results: Mean improvements greater than the minimum clinically important difference (MCID) were seen in MOxFQ-Pain (61.7±26.1 to 48.3±21.8, p=0.112), MOxFQ-Walking (64.6±21.8 to 46.6±23.9, p=0.067), MOxFQ-Social (63.67±22.5 to 41.8±29.2, p=0.055), although none reached statistical significance. No difference was seen in EQ5D. Overall improvements were seen in MOxFQ-Pain in 58.3%, MOxFQ-Walking in 75%, and MOxFQ-Social in 83.3% of patients. Overall, 11 patients (73.3%) were satisfied with the procedure. Patients displayed improvement in plantarflexion from 33.1±5.5 to 42.0±7.9 degrees (p=0.002) and no change to dorsiflexion. There were no complications. Conclusion: The H-AMIC procedure is a promising and safe option for larger osteochondral lesions of the talus. Early results suggest improved range of motion despite osteotomy and clinically (but not statistically) significant improvement in function in a group of patients with longstanding symptoms and previous failed surgery. Larger, adequately powered cohorts may establish statistical efficacy of this technique compared with alternative techniques.

Background: A previous study defined the normal first metatarsal pronation angle (MPA) as <16 degrees and normal α angle as <18 degrees. The primary purpose of this study was to assess the side-to-side variation in first metatarsal pronation between feet in normal individuals. Methods: MPA and α angles were measured on standardized coronal weightbearing computed tomography slices. Pairedt tests were used to test significance of mean side-to-side differences in a population of 63 normal, asymptomatic individuals. Results: The mean side-to-side difference in first metatarsal pronation was 4.3 degrees (95% CI 3.3, 5.2 degrees) for MPA and 4.9 degrees (95% CI 3.8, 6.0 degrees) for α angle. The normative range for side-to-side difference was calculated as 12 degrees for MPA and 14 degrees for α angle, as defined by 2 SDs from the mean. Conclusion: In a cohort of normal patients, the mean difference in first metatarsal pronation between sides was approximately 4 to 5 degrees based on MPA and α angle. However, considerable variation in differences was observed. These findings may be considered when assessing first metatarsal pronation using population-based values as it may influence thresholds for identifying pathology in an individual.

Background: Foot and ankle deformities have translational and rotational components in multiple planes, at multiple levels. Semi-automatic segmentation is a relatively new technology, which when used with weight-bearing CT (WBCT), can build an accurate model of the foot and calculate the orientation and re-lationships of bones under physiological load. However, few papers report reference values using these techniques. We report normative values for key bony relationships based on semi-automated analysis of WBCT.Methods: This was a single-centre, retrospective analysis of 100 feet without deformity from 55 adult patients undergoing WBCT as part of routine clinical activity (mean age 40.5 +/- 17.3 years). Imaging was analysed using Bonelogic 2.1 (DISIOR, Finland). Semi-automatic segmentation was used to compute the various bony axes in 3-dimensional space. Selected coronal, axial and sagittal plane relationships were then calculated for bones of the hindfoot, midfoot and forefoot.Results: Data is presented on axial and sagittal plane relationships between the metatarsals in the forefoot, and the metatarsals and cuneiforms in the midfoot. In the hindfoot, the calcaneal pitch, talar-first-meta-tarsal angles, talonavicular coverage angles and Saltzman angles are reported. Coronal plane axes and their relationships are reported at multiple levels from hindfoot to forefoot. Results are presented as mean values with standard deviations and 95% confidence intervals.Conclusions: We present an observational analysis of the normal values from non-deformed feet. We highlight the major relationships in the axial, sagittal and coronal planes as obtained by semi-automated analysis of WBCT. This data may serve as a reference for future research. Level of evidence: Basic science study (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of European Foot and Ankle Society. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Background: Hallux valgus is a common foot condition with numerous surgical techniques described. Minimally invasive surgery is becoming more popular, with resultant development of suitable fixation devices. The aim of this systematic review was to evaluate the evidence on the use of intramedullary devices in hallux valgus first metatarsal corrective osteotomies, and describe clinical and radiological outcomes, with an overview of techniques and implants used. Methods: We searched PubMed, Medline, Embase and EMCare databases, conforming to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Radiological outcomes including the hallux valgus angle (HVA) and intermetatarsal angle (IMA) were recorded, as well as clinical outcome scores and complications. Methodological quality of included studies was assessed using the MINORS score. Results: Ten studies were included, comprising 696 feet in 745 patients. Data pooling and metanalysis was not possible due to overall low quality of evidence. Four implants were reported (Endolog, ISO Plate, V-Tek Plate, Link Fixator) and used with distal first metatarsal osteotomies, with improvement in HVA, IMA, and clinical outcome scores comparable to other fixation techniques. There were no reported cases of nonunion. Complication rates were variable (all cause range of 0-21%) across all studies, with an overall low rate. Conclusion: Intramedullary devices are viable and safe to use for hallux valgus first metatarsal osteotomies, with comparable radiological and functional outcomes to other techniques. Current evidence base is of low methodological quality, therefore high quality studies are required to further evaluate these devices. Crown Copyright (c) 2021 Published by Elsevier Ltd on behalf of European Foot and Ankle Society. All rights reserved.

Background: Failure to identify and correct malrotation of the first metatarsal may lead to recurrent hallux valgus deformity. We aimed to identify the proportion of hallux valgus patients with increased first metatarsal pronation using weightbearing computed tomography (WBCT) and to identify the relationship with conventional radiographic measurements. Methods: WBCT scans were analyzed for 102 feet with a hallux valgus angle (HVA) and intermetatarsal angle (IMA) greater than or equal to 16 and 9 degrees, respectively. Metatarsal pronation angle (MPA), alpha angle, sesamoid rotation angle (SRA), and sesamoid position were measured on standardized coronal WBCT slices. Pronation was recorded as positive. Hindfoot alignment angle (HAA) was assessed using dedicated software. Pearson correlation and multiple regression analyses were used to assess differences between groups. Results: Mean HVA was 29.8±9.4 degrees and mean IMA was 14.1±3.7 degrees. Mean MPA was 11.9±5.8 (range 0-26) degrees and mean alpha angle was 11.9±6.8 (range −3 to 29) degrees. In a previous study, we demonstrated the upper limit of normal MPA as 16 degrees and alpha angle as 18 degrees. Based on these criteria, we identified abnormal metatarsal pronation in 32 feet (31.4%). We found a strong positive correlation between SRA and HVA/IMA (R = 0.67/0.60, respectively, P < .001). IMA and HAA weakly correlated with MPA and alpha angle (IMA: R = 0.26/0.27, respectively, P < .01; HAA: R = 0.26/0.27, respectively, P < .01). Regression analyses suggested that increasing IMA was the most significant radiographic predictor of increased pronation. In this cohort, there was no correlation between HVA or sesamoid position and MPA / alpha angle (HVA: P = .36/.12, respectively, sesamoid position, P = .86/.77, respectively). Conclusion: In this cohort of 102 feet that met plain radiographic criteria for hallux valgus deformity, first metatarsal pronation was found abnormal in 31.4% of patients. We found a weak association between the IMA and hindfoot valgus, but not the HVA.