Forefoot Morphotypes in Cavovarus Feet: A Novel Assessment of Deformity.

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.

Classifications in adult pes cavus - A scoping review.

AIMS: The 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. METHODS: As 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. RESULTS: A total of 1140 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. CONCLUSIONS: There 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.

Talar neck rotation angle in adults with clubfoot deformity: Observed values and intra- and inter-observer reliability using weightbearing CT.

INTRODUCTION: 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. LEVEL OF CLINICAL EVIDENCE: 3.

Outcomes of Tenosynovial Giant Cell Tumor of the Foot and Ankle.

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.

First Metatarsal Rotation After Scarf Osteotomy for Hallux Valgus.

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.

Analysis of the 50 Most Cited Articles on Achilles Tendon Injury.

Background: Achilles tendon injuries represent one of the most common reasons for referral to orthopaedic surgeons. Purpose: To outline the characteristics, examine trends in publication, and evaluate the correlation between citations and study quality of the 50 most cited articles on Achilles tendon injury. Study Design: Cross-sectional study. Methods: After searching the Web of Science for articles published in orthopaedic journals, we identified the 50 most cited articles on Achilles tendon injury and abstracted their characteristics. Risk of bias was assessed using the modified Coleman Methodology Score (mCMS). Multiple bivariate analyses (Pearson or Spearman correlation coefficient) were used to evaluate the association among number of citations, citation rate (citations/year), 2020 journal impact factor (JIF), year of publication, level of evidence (LoE), study type (tendon rupture or chronic tendinopathy), sample size, and mCMS. Results: The top 50 articles were cited 12,194 times. Each article had a mean ± SD 244 ± 88.8 citations (range, 157-657) and a citation rate of 12.6 ± 5.4 per year (range, 3-28). A total of 35 studies (70%) were published between 2000 and 2010. The citation rate of the 16 most recent studies was almost double that of the 16 oldest studies (17.5 vs 9.9; P < .001). Nineteen studies (49%) were classified as having poor quality (mCMS <50 points). The mean JIF of the 9 journals that published the studies was 5.1. The citation rate correlated with the number of citations (r = 0.56; P < .001), publication year (r = 0.60; P < .001), and LoE (r = -0.44; P = .005). The publication year correlated with the LoE (r = -0.40; P = .01). Study quality in terms of mCMS correlated with the JIF (r = 0.35; P = .03) and LoE (r = -0.48; P = .003) but not the citation rate (P = .15). Conclusion: The mean LoE and the citation rate of the most cited articles on Achilles tendon injury both significantly increased over time. Although the JIF was positively correlated with study quality, almost half of the studies had poor-quality methodology.

Assessing the coronal plane deformity in Charcot Marie Tooth Cavovarus feet using automated 3D measurements.

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 software. METHODS: WBCTs from 30 CMT-cavovarus feet were matched to 30 controls and analysed using semi-automatic 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. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

What is the best fixation technique for isolated talonavicular arthrodesis? - A systematic review.

Talonavicular arthrodesis is associated with a rate of non-union that ranges from 3 % to 37 %. Various fixation devices have been reported for talonavicular arthrodesis including screws, staples, plates, K-wires and intraosseous fix systems, however there is no definitive gold standard. This systematic review aims to compare clinical outcomes between different fixation devices for talonavicular arthrodesis. METHODS: MEDLINE, EMBASE, CENTRAL and Google Scholar were reviewed for studies reporting on outcomes of different fixation techniques for talonavicular arthrodesis indicated for osteoarthritis, inflammatory and post-traumatic arthritis from 1946 to 2021. The primary outcome measure was union rate. Secondary outcome measures included functional improvement, cost, quality of life and patient satisfaction. RESULTS: 9 articles involving 141 cases of talonavicular arthrodesis were identified. Fusion rates were as follows: screw fixation (n = 75): 87.5 % to 100 %, staple fixation (n = 13): 100 %, intraosseous fix system (n = 16): 100 %, and K-wire fixation (n = 2): 100 %. One study utilised a dorsal locking plate with two supplemented compression screws (n = 9, fusion rate= 100 %) and two studies used a combination of screws with staples (n = 26, fusion rate= 96 %). 7 of 9 studies measured functional outcomes and pain relief with improvement demonstrated in all fixation techniques. Quality of life, satisfaction and cost were inadequately reported amongst the included studies. All studies were rated as serious risk of bias. CONCLUSION: This systematic review consolidates the evidence for outcomes of different fixation techniques for TN arthrodesis, however a definitive judgement regarding the best fixation technique is unobtainable from current clinical evidence, due to lack of high-quality studies. With review of biomechanical studies and the limited clinical data, fixation with plate plus screw is most promising and would warrant further comparative study. LEVEL OF EVIDENCE: IV.

Semi-automated 3-dimensional analysis of the normal foot and ankle using weight bearing CT - A report of normal values and bony relationships.

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 relationships 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-metatarsal 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.

2D Manual vs 3D Automated Assessment of Alignment in Normal and Charcot-Marie-Tooth Cavovarus Feet Using Weightbearing CT.

BACKGROUND: The complex deformities in cavovarus feet may be difficult to assess and understand. Weightbearing computed tomography (WBCT) is increasingly used in evaluating 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 or deformity. This study aimed to assess differences in measurements done manually on 2D slices of WBCT vs 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 disease. Six measurements were assessed: talar-first metatarsal angle (axial plane), forefoot arch angle (coronal plane), and Meary angle, calcaneal pitch, and cuneiform and navicular to floor distances (sagittal plane). 2D measurements were performed manually and 3D measurements were performed using specialized software (Bonelogic, DISIOR). Bland-Altman plots and linear regression were used to analyze differences. RESULTS: There were no significant biases in measured variables in normal feet. In the cavovarus group, automated assessment calculated increased sagittal plane deformity (fixed bias 7.31 degrees for Meary angle, 2.39 degrees for calcaneal pitch) and less axial plane deformity (fixed bias 10.61 degrees for axial talar-first metatarsal angle). The latter also demonstrated proportional bias indicating greater discrepancy with increasing adduction. CONCLUSION: Measurements were comparable in normal feet suggesting automated techniques can reliably assess the alignment of bony axes. However, automated calculations show greater sagittal and less axial deformity in cavovarus feet than measured by manual techniques. This discrepancy may relate to rotational deformity seen in cavovarus feet, which may not be easily assessed manually. 3D automated measurements may therefore play a role in better assessing and classifying the cavovarus foot, which may ultimately inform treatment algorithms. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Side-to-Side Difference of Metatarsal Rotation in Normal Individuals.

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.

Imaging Findings and First Metatarsal Rotation in Hallux Valgus.

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.

The use of intramedullary devices for fixation of metatarsal osteotomies in hallux valgus surgery - A systematic review.

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 non-union. 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.

Subtalar Arthroereisis as an Adjunct Procedure Improves Forefoot Abduction in Stage IIb Adult-Acquired Flatfoot Deformity.

BACKGROUND: Our aims were (a) to determine whether subtalar arthroereisis (STA) as adjunct procedure improved radiographic correction of stage IIb adult-acquired flexible flatfoot deformity (AAFD); (b) to assess the STA-related complication rate. METHODS: A retrospective analysis of 22 feet (21 patients) diagnosed with stage IIb AAFD treated by medializing calcaneal osteotomy (MCO), flexor digitorum longus (FDL) transfer, spring ligament (SL) repair with or without Cotton osteotomy and with or without STA in a single institution was carried out. Seven measurements were recorded on pre- and postoperative (minimum 24 weeks) radiographs by 2 observers and repeated twice by 1 observer. Inter- and intraobserver reliabilities were assessed. The association of demographic (gender, side, age, body mass index) and surgical variables (Cotton, STA) with radiographic change was tested with univariate analysis followed by a multivariable regression model. RESULTS: Excellent inter- and intraobserver reliabilities were demonstrated for all measurements (intraclass correlation coefficient range, 0.75-0.99). Gender, side, Cotton osteotomy, and STA were included in the multivariable analysis. Regression showed that STA was the only predictor of change in talonavicular coverage angle (TNCA) (R2 = 0.31; P = .03) and in calcaneo-fifth metatarsal angle (CFMA) (R2 = 0.40; P = .02) on dorsoplantar view. STA was associated to a greater change in TNCA by 10.1° and in CFMA by 5°. Four patients out of 12 STA complained of sinus tarsi pain after STA, and removal of the implant resolved symptoms in 3 of them. CONCLUSION: In this series, STA as an adjunct procedure to MCO, FDL transfer, SL repair in the treatment of stage IIb AAFD led to improvement in correction of forefoot abduction. STA-related complication and removal rates were 33%. LEVELS OF EVIDENCE: Level IV: Retrospective cohort study.

Use of intramedullary locking nail for displaced intraarticular fractures of the calcaneus: what is the evidence?

INTRODUCTION: Intramedullary locking devices (ILDs) have recently been advocated as a minimally invasive approach to manage displaced intraarticular calcaneal fractures (DIACFs), to minimise complications and improve outcomes. We reviewed clinical and biomechanical studies dealing with commercially available devices to identify their characteristics, efficacy and safety. METHODS: Following a PRISMA checklist, Medline, Scopus and EMBASE databases were searched to identify studies reporting the use of ILDs for treating DIACFs. Biomechanical studies were first evaluated. Cohort studies were then reviewed for demographics, surgical technique, postoperative protocol, clinical and radiographic scores, complications and reoperations. The modified Coleman Methodology Score (CMS) was used to assess the quality of studies. RESULTS: Eleven studies were identified which investigated two devices (Calcanail®, C-Nail®). Three biomechanical studies proved they offered adequate primary stability, stiffness, interfragmentary motion and load to failure. Eight clinical studies (321 feet, 308 patients) demonstrated a positive clinical and radiographic outcome at 16-months average follow-up. Metalware irritation (up to 20%) and temporary nerve entrapment symptoms (up to 30%) were the most common complications, while soft tissue issues (wound necrosis, delayed healing, infection) were reported in 3-5% of cases. Conversion to subtalar fusion was necessary in up to 6% of cases. Four (50%) out of 8 studies were authored by implant designers and in 5 (62%) relevant conflicts of interest were disclosed. Mean (± standard deviation) CMS was 59 ± 9.8, indicating moderate quality. CONCLUSIONS: Treating DIAFCs with ILDs leads to satisfactory clinical outcomes at short-term follow-up, enabling restoration of calcaneal height and improved subtalar joint congruency. Metalware irritation and temporary nerve entrapment symptoms are common complications although wound complications are less frequent than after open lateral approaches. The quality of evidence provided so far is moderate and potentially biased by the conflict of interest, raising concerns about the generalisability of results. LEVEL OF EVIDENCE: Level V - Review of Level III to V studies.

Repeatability of Weightbearing Computed Tomography Measurement of First Metatarsal Alignment and Rotation.

BACKGROUND: Weightbearing computed tomography (WBCT) can be used to assess alignment and rotation of the first metatarsal. It is unknown whether these measures remain consistent on sequential WBCTs in the same patient when a patient's standing position may be different. The aim of this study was to establish the repeatability (test-retest) of measurements of first metatarsal alignment and rotation in patients without forefoot pathology on WBCT. METHODS: We retrospectively identified 42 feet in 26 patients with sequential WBCT studies less than 12 months apart. Patients with surgery between scans, previous forefoot surgery or hallux rigidus were excluded. Hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured using digitally reconstructed radiographs. Two methods of calculating metatarsal rotation (metatarsal pronation angle [MPA] and alpha angle) were measured on standardized coronal CT slices. Interobserver agreement and test-retest repeatability were assessed using intraclass correlation coefficients (ICCs). Standard error of measurement (SEM) and minimally detectable change (MDC95) were calculated. RESULTS: Interobserver agreement was excellent for HVA and IMA (ICC 0.96 and 0.90, respectively) and was good for MPA and alpha angle (ICC 0.81 and 0.80, respectively). There was excellent test-retest repeatability for HVA (ICC=0.90) and good test-retest repeatability for IMA (ICC=0.77). There was excellent test-retest repeatability for MPA (ICC=0.91) and good test-retest repeatability for alpha angle (ICC=0.87). The MDC95 was 4.6 degrees for MPA and 6.1 degrees for alpha angle. Five percent of patients had a difference outside of the MDC95 for the alpha angle, compared with 2% for the MPA. CONCLUSION: Measurements of first metatarsal alignment and rotation are reliable between assessors and repeatable between sequential WBCTs in patients without forefoot pathology. Subtle differences in patient positioning during image acquisition do not significantly affect measurements, supporting the validity of this method of assessment in longitudinal patient care. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Assessing the Rotation of the First Metatarsal on Computed Tomography Scans: A Systematic Literature Review.

BACKGROUND: Hallux valgus is a multiplanar deformity that is often treated on the basis of 2-dimensional (2D) parameters and radiographs. Recurrence rates after surgical correction remain high, and failure to correct pronation of the metatarsal is increasingly stipulated as being part of the problem. Multiple methods of assessing metatarsal pronation have been proposed. METHODS: We performed a systematic literature review identifying studies that measured metatarsal pronation and torsion on computed tomography (CT) scans. Specific methodology, patient groups, results, and reliability assessments were all reported. RESULTS: We identified 14 studies that fulfilled the inclusion criteria. Eleven studies measured 2D values on CT scan, and 3 studies used computer-based 3-dimensional (3D) modeling and artificial intelligence systems to help calculate pronation. Metatarsal pronation angle, α angle, sesamoid rotation angle, and measurements for torsion were the most commonly used methods. All angles and measurements were performed as 2D measurements, but the metatarsal pronation angle was also performed with 3D modeling. Reliability and reproducibility of the α angle and metatarsal pronation angle were excellent, despite being performed on studies with small numbers. CONCLUSION: Multiple methods have been reported to demonstrate first metatarsal pronation on CT, of which the α angle and the metatarsal pronation angle are the most pragmatic and useful in a clinical setting. Further work is needed to further validate the reliability of these measurements in larger series and to identify normal pronation and metatarsal torsion on weightbearing imaging. Further work is required to determine whether addressing pronation reduces recurrence rates and improves outcomes in surgery for hallux valgus. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Limb salvage versus below knee amputation for severe adult lower limb deformity - A retrospective, comparative series.

BACKGROUND: This study compares outcomes of patients with severe, multiplanar, fixed, pantalar deformities undergoing limb preservation with either pantalar fusion (PTF) or talectomy and tibiocalcaneal fusion (TCF), versus below knee amputation (BKA). METHODS: Fifty-one patients undergoing either PTF, TCF and BKA for failed management of severe pantalar deformity were evaluated retrospectively. Twenty-seven patients underwent PTF, 8 TCF and 16 BKA. Median age at surgery was 55.0 years (17-72 years) and median follow-up duration was 49.9 months (24.0-253.7 months). Clinical evaluation was undertaken using the MOxFQ, EQ-5D and Special Interest Group in Amputee Medicine score (SIGAM). Patients were also asked whether they were satisfied with their surgery and whether they would have the same surgery again. RESULTS: There was no statistically significant difference in functional outcomes, satisfaction, or complications between the groups. Twenty-two patients undergoing PTF (81.5%), 6 patients undergoing TCF (75%), and 15 patients undergoing BKA (93.8%) were satisfied overall (p = 0.414). There was no difference in the proportion of patients who would opt for the same procedure again (p = 0.142): 23 in the PTF group (85.2%), 8 in the TCF group (100%), and 11 in the BKA group (68.8%). Seven patients undergoing PTF (25.9%), 2 patients undergoing TCF (25%) and 6 patients undergoing BKA (37.5%) had major complications (p = 0.692). CONCLUSION: This study concludes that PTF, TCF and BKA can all provide an acceptable outcome in treatment of severe, degenerative pantalar deformities. This data may be useful in counselling patients when considering salvage versus amputation in such cases. LEVEL OF EVIDENCE: Level 3(Original) Clinical Research Article.

The Value of SPECT-CT in Diagnosing Complex Non-Arthritic and Non-Neoplastic Conditions of the Foot and Ankle.

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.

Static versus dynamic fixation of distal tibiofibular syndesmosis: a systematic review of overlapping meta-analyses.

PURPOSE: Multiple Level I meta-analyses were conducted comparing traditional static vs. more recently introduced dynamic strategies of fixation for injuries of the distal tibiofibular syndesmosis (TFS). The aim of this review was to assess their robustness and methodological quality, providing support in the choice of a treatment strategy in case of TFS injury using the highest level of evidence. METHODS: In this systematic review, conducted in accordance with the PRISMA guidelines, meta-analyses/systematic reviews comparing static and dynamic fixation methods after acute TFS injury were identified. The robustness of studies was evaluated using the fragility index (FI) for meta-analysis and the fragility quotient (FQ). The risk of bias was evaluated using the Assessment of Multiple Systematic Reviews (AMSTAR) instrument. Finally, the Jadad was applied to select the study which provided the highest quality of evidence to develop recommendations for the fixation strategy of these lesions. RESULTS: Out of 1.302 records, four Level I meta-analyses were included in this study. Analyzing the statistically significant dichotomous outcomes, the median FI was 3.5 (IQR, 2 to 5.5; range, 1 to 9), while the median FQ was 1.9% (IQR, 1 to 3.5; range 0.35 to 4.4). In total, 37% had an FI of 2 or less and 75% of outcomes had a FI of 4 or less. According to the AMSTAR score and Jadad algorithm, the largest meta-analysis was selected as the highest evidence provided so far. CONCLUSION: The meta-analyses with statistically significant dichotomous outcomes comparing dynamic and static fixation for treating injuries of the distal tibiofibular syndesmosis are fragile, with a change in less than four patients or less than 2% of the study population sufficient to reverse a significant outcome to nonsignificant. LEVEL OF EVIDENCE: Level I.