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.

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.

The position, orientation, and relative size of the fibularis longus tubercle in normal patients: A weightbearing CT assessment

The fibularis longus attaches to the base of the first metatarsal at the fibularis/peroneus longus tubercle (FLT/PLT). Theoretically, differences in FLT morphology may reflect changes in the function of the fibularis longus. This study defines the normal limits of the FLT position, orientation, and size in patients with morphologically normal foot anatomy. A retrospective analysis of 131 feet without deformity in 72 patients undergoing weightbearing CT (WBCT) at a single center was conducted. The position and morphology of the FLT was assessed with novel measurements including tubercle-floor distance, tubercle-metatarsal angle, and the angle between the floor and a line bisecting the FLT (bisecting angle). Roundness of the FLT was compared to a triangle limiting its shape (triangular ratio), with lower values indicating increasing roundness. We also report relative size of the FLT to the first metatarsal (X/Y ratio), and relative size of the first metatarsal and FLT to the second metatarsal (XY/Z ratio). There were no significant side to side differences for any measurement (p > 0.05). Mean values were: tubercle-floor distance 28.02 ± 2.63 mm, tubercle-metatarsal angle 32.7 ± 6.32 degrees, bisecting angle 65.58 ± 6.27 degrees, triangular ratio 0.69 ± 0.04, X/Y ratio 1.13 ± 0.20, and XY/Z ratio 3.44 ± -0.72. Bisecting angle strongly correlated with tubercle-metatarsal angle (Pearson correlation 0.840, p < 0.001) suggesting FLT rotation occurred independent of foot position. ICC was >0.943 for all measurements. This study reports the morphology of the FLT in individuals with normal feet. This normative data may be used in future studies examining differences between groups of patients with foot pathology, helping us better understand the role of fibularis longus in the development and treatment of foot disorders.

Structural validation of the Manchester-Oxford Foot Questionnaire for use in foot and ankle surgery

Aims

The Manchester-Oxford Foot Questionnaire (MOxFQ) is an anatomically specific patient-reported outcome measure (PROM) currently used to assess a wide variety of foot and ankle pathology. It consists of 16 items across three subscales measuring distinct but related traits: walking/standing ability, pain, and social interaction. It is the most used foot and ankle PROM in the UK. Initial MOxFQ validation involved analysis of 100 individuals undergoing hallux valgus surgery. This project aimed to establish whether an individual's response to the MOxFQ varies with anatomical region of disease (measurement invariance), and to explore structural validity of the factor structure (subscale items) of the MOxFQ.

Methods

This was a single-centre, prospective cohort study involving 6,637 patients (mean age 52 years (SD 17.79)) presenting with a wide range of foot and ankle pathologies between January 2013 and December 2021. To assess whether the MOxFQ responses vary by anatomical region of foot and ankle disease, we performed multigroup confirmatory factor analysis. To assess the structural validity of the subscale items, exploratory and confirmatory factor analyses were performed.

Results

Measurement invariance by pathology was confirmed, suggesting the same model can be used across all foot and ankle anatomical regions. Exploratory factor analysis demonstrated a two- to three-factor model, and suggested that item 13 (inability to carry out work/everyday activities) and item 14 (inability to undertake social/recreational activities) loaded more positively onto the "walking/standing" subscale than their original "social interaction" subscale.

Conclusion

This large cohort study supports the current widespread use of the MOxFQ across a broad range of foot and ankle pathologies. Our analyses found indications that could support alterations to the original factor structure (items 13 and 14 might be moved from the "social interaction" to the "walking/standing" subscale). However, this requires further work to confirm.

3-D joint space mapping at the ankle from weight-bearing CT: reproducibility, repeatability, and challenges for standardisation

OBJECTIVES

We present a 3-D approach to joint space width (JSW) measurement across the ankle from weight-bearing CT (WBCT) to demonstrate inter-operator reproducibility, test-retest repeatability, and how differences in angulation affect ankle JSW distribution.

METHODS

One side from repeat WBCT imaging of both feet and ankles was analysed from 23 individuals as part of their routine clinical care pathway. Joint space mapping was performed at four facets across the talus: talonavicular, talar dome and medial gutter (dome-medial), lateral gutter, and posterior subtalar. Inter-operator reproducibility was calculated for two users, while test-retest repeatability was calculated by comparing the two visits, both presented as Bland-Altman statistics. Statistical parametric mapping determined any significant relationships between talocrural joint space angulation and 3-D JSW distribution.

RESULTS

The average ± standard deviation interval between imaging was 74.0 ± 29.6 days. Surface averaged bias ± limits of agreement were similar for reproducibility and repeatability, the latter being: talonavicular 0.01 ± 0.26 mm, dome-medial 0.00 ± 0.28 mm, lateral gutter - 0.02 ± 0.40 mm, and posterior subtalar 0.02 ± 0.34 mm. Results are presented as 3-D distribution maps, with optimum test-retest repeatability reaching a smallest detectable difference of ± 0.15 mm.

CONCLUSIONS

Joint space mapping is a robust approach to 3-D quantification of JSW measurement, inter-operator reproducibility, and test-retest repeatability at the ankle, with sensitivity reaching a best value of ± 0.15 mm. Standardised imaging protocols and optimised metal artefact reduction will be needed to further understand the clinical value of these 3-D measures derived from WBCT.

CLINICAL RELEVANCE STATEMENT

Weight-bearing computed tomography is an increasingly important tool in the clinical assessment of orthopaedic ankle disorders. This paper establishes the performance of measuring 3-D joint space width using this technology, which is an important surrogate marker for severity of osteoarthritis.

KEY POINTS

• Joint space width values and error metrics from across the ankle measured from weight-bearing CT can be presented as 3-D maps that show topographic variation. • The best sensitivity for detecting meaningful change in 3-D joint space width at the ankle was ± 0.15 mm, a value less than the isotropic imaging voxel dimensions. • Standardised imaging protocols and optimised metal artefact reduction will be needed to understand the clinical value of 3-D measures from weight-bearing CT.

CYP2D6 Activity Is Correlated with Changes in Plasma Concentrations of Taurocholic Acid during Pregnancy and Postpartum in CYP2D6 Extensive Metabolizers

Cytochrome P450 2D6 (CYP2D6) is involved in the metabolism of >20% of marketed drugs. CYP2D6 expression and activity exhibit high interindividual variability and is induced during pregnancy. The farnesoid X receptor (FXR) is a transcriptional regulator of CYP2D6 that is activated by bile acids. In pregnancy, elevated plasma bile acid concentrations are associated with maternal and fetal risks. However, modest changes in bile acid concentrations may occur during healthy pregnancy, thereby altering FXR signaling. A previous study demonstrated that hepatic tissue concentrations of bile acids positively correlated with the hepatic mRNA expression of CYP2D6. This study sought to characterize the plasma bile acid metabolome in healthy women (n = 47) during midpregnancy (25-28 weeks gestation) and ≥3 months postpartum and to determine if plasma bile acids correlate with CYP2D6 activity. It is hypothesized that during pregnancy, plasma bile acids would favor less hydrophobic bile acids (cholic acid vs. chenodeoxycholic acid) and that plasma concentrations of cholic acid and its conjugates would positively correlate with the urinary ratio of dextrorphan/dextromethorphan. At 25-28 weeks gestation, taurine-conjugated bile acids comprised 23% of the quantified serum bile acids compared with 7% ≥3 months postpartum. Taurocholic acid positively associated with the urinary ratio of dextrorphan/dextromethorphan, a biomarker of CYP2D6 activity. Collectively, these results confirm that the bile acid plasma metabolome differs between pregnancy and postpartum and provide evidence that taurocholic acid may impact CYP2D6 activity during pregnancy. SIGNIFICANCE STATEMENT: Bile acid homeostasis is altered in pregnancy, and plasma concentrations of taurocholic acid positively correlate with CYP2D6 activity. Differences between plasma and/or tissue concentrations of farnesoid X receptor ligands such as bile acids may contribute to the high interindividual variability in CYP2D6 expression and activity.

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.

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.

Dressing Materials: A Comprehensive Review

Injury to the skin provides a difficult challenge, as wound healing is a complex and dynamic process. Wound healing process recruits three different phases: inflammation, proliferation, and maturation. The sequence of events involved in wound healing can be affected by numerous disease processes, resulting in chronic, non-healing wounds that give significant discomfort and distress to the patients while draining the medical fraternity of enormous resources. Wound tissue never reaches its pre-injured strength and multiple aberrant healing states can result in chronic non-healing wounds. There is a growing concern about the usage of correct materials for wound dressings. The development of new and effective treatments in wound care still remains an area of intense research. There are a number of wound dressings available in the market. The objective of the article is to enhance knowledge about characteristics of an ideal wound dressing and guide in finding the correct dressing material. It also provides a detailed classification of traditional and modern wound dressings.

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.

Lanthanide-Doped Upconversion Nanoparticles: Exploring A Treasure Trove of NIR-Mediated Emerging Applications

Lanthanide-doped upconversion nanoparticles (UCNPs) possess the remarkable ability to convert multiple near-infrared (NIR) photons into higher energy ultraviolet-visible (UV-vis) photons, making them a prime candidate for several advanced applications within the realm of nanotechnology. Compared to traditional organic fluorophores and quantum dots (QDs), UCNPs possess narrower emission bands (fwhm of 10-50 nm), large anti-Stokes shifts, low toxicity, high chemical stability, and resistance to photobleaching and blinking. In addition, unlike UV-vis excitation, NIR excitation is nondestructive at lower power intensities and has high tissue penetration depths (up to 2 mm) with low autofluorescence and scattering. Together, these properties make UCNPs exceedingly favored for advanced bioanalytical and theranostic applications, where these systems have been well-explored. UCNPs are also well-suited for bioimaging, optically modulating chemistries, forensic science, and other state-of-the-art research applications. In this review, an up-to-date account of emerging applications in UCNP research, beyond bioanalytical and theranostics, are presented including optogenetics, super-resolution imaging, encoded barcodes, fingerprinting, NIR vision, UCNP-assisted photochemical manipulations, optical tweezers, 3D printing, lasing, NIR-II imaging, UCNP-molecule nanohybrids, and UCNP-based persistent luminescent nanocrystals.

An Updated Review on Current Treatment of Alopecia Areata and Newer Therapeutic Options

Alopecia areata (AA) is a dermatological disease that causes nonscarring hair loss. It can occur at any age and has an unpredictable and variable evolution in individuals. The aim of this review is to provide an update on the novel therapies currently being used, as well as upcoming therapeutic options in the treatment of AA.

An interprofessional clinic for adults with Turner syndrome: the patient perspective

OBJECTIVES

This qualitative study assessed the value of a primary care-based interprofessional clinical team for adults with Turner syndrome (TS) utilizing patient perspectives.

METHODS

Ten patients within one institution's interprofessional adult TS clinic participated in one of two semi-structured focus groups. Content analysis was used to classify content provided by participants into themes and sub-themes using Dedoose software.

RESULTS

Participants found that their quality of care and life were both improved due to the presence of the interprofessional Adults with TS Clinic. Specifically, participants reported that the clinic helped address problems with finding knowledgeable providers and care gaps, made appointments more convenient and improved interprofessional communication. Participants also reported that the clinic helped them find a sense of community and increased personal confidence. Study participants suggested improvements to the clinic by expanding the scope of practice further, simplifying processes to schedule appointments, and potentially creating interprofessional clinics for other rare diseases as well.

CONCLUSION

Pursuing avenues to create interprofessional clinics for adults with rare diseases has value from the patient perspective. This value can translate to improved patient outcomes through improvements in patient knowledge of their diagnosis, adherence to evidence-based care and quality of life.

Rate of COVID-19 Infection and 30 Day Mortality Between Blue and Green (Dedicated COVID-19 Safe) Pathways: Results From the UK Foot and Ankle COVID-19 National-Audit

Category:

Other

Introduction/Purpose:

Objectives: The primary aim was to determine the differences in COVID-19 infection rate and 30-day mortality in patients undergoing foot and ankle surgery between different treatment pathways over the two phases of the UK- FALCON audit, spanning the first and second national lockdowns.

Methods:

Setting: This was an ambispective (retrospective Phase 1 and prospective Phase 2) national audit of foot and ankle procedures in the UK in 2020 completed between 13th January 2020 and 30th November 2020.Participants: All adult patients undergoing foot and ankle surgery in an operating theatre during the study period were included from 46 participating centres in England, Scotland, Wales and Northern Ireland. Patients were categorised as either a green pathway (designated COVID-19 free) or blue pathway (no protocols to prevent COVID-19 infection).

Results:

10,846 patients were included, 6,644 from phase 1 and 4,202 from phase 2. Over the 2 phases the infection rate on a blue pathway was 1.07% (69/6,470) and 0.21% on a green pathway (9/4,280). In phase 1, there was no significant difference in the COVID-19 perioperative infection rate between the blue and green pathways in any element of the first phase (pre-lockdown (p=.109), lockdown (p=.923) or post-lockdown (p=.577)). However, in phase 2 there was a significant reduction in perioperative infection rate when using the green pathway in both the pre-lockdown (p<.001) and lockdown periods (Odd's Ratio 0.077, p<.001). There was no significant difference in COVID-19 related mortality between pathways.

Conclusion:

There was a five-fold reduction in the perioperative COVID-19 infection rate when using designated COVID-19 green pathways over the whole study period; however the success of the pathways only became significant in phase 2 of the study, where there was a 13-fold reduction in infection rate. The study shows a developing success to using green pathways in reducing the risk to patients undergoing foot and ankle surgery.

Plain Radiographs are Insufficient for Evaluation of First Metatarsal Pronation in Patients Undergoing Surgery for Hallux Valgus

Category:

Midfoot/Forefoot; Bunion

Introduction/Purpose:

Previous studies using weight-bearing CT (WBCT) have suggested that up to 30% of patients with hallux valgus may have excessive pronation of the first metatarsal when defined as a metatarsal pronation angle (MPA) of greater than 16 degrees (Najefi et al.). The MPA is calculated on coronal slices of a CT or MRI, but axial imaging is not the norm in the assessment of these patients. It is however unclear how accurate radiographs are at determining pronation. This study aimed to assess the degree of pre-operative first metatarsal pronation in patients undergoing surgery for hallux valgus using radiographs and WBCT.

Methods:

This was a retrospective review of patients undergoing scarf osteotomy for hallux valgus correction. Patients were included if they had both plain radiographs and WBCT. Patients were excluded if they had any prior surgery to the foot in question. Pre-operative weightbearing plain radiographs of the foot were analyzed and the classification by Okuda et al. was used to determine if pronation was present using the shape of the lateral edge of first metatarsal head. Pre-operative WBCTs were reviewed and MPA calculated. Twenty-two feet were included.

Results:

In total 10 feet (45.5%) had an ‘angular’ first metatarsal head, 9 (40.9%) had an ‘intermediate’ head shape, and 3 (13.6%) had a ‘round’ head on plain radiographic assessment. The overall mean MPA was 16.25 degrees (range 2.1-30), and 12 (54.5%) feet had an MPA of greater than 16 degrees (excessively pronated). There was a strong correlation between increasing MPA and increasing roundness of the metatarsal head (Eta = 0.952). The mean MPA was 14.4 degrees in the angular head group, 17.0 degrees in the intermediate group, and 20.1 degrees in the round head group. In the intermediate and round groups 9 feet (75%) had greater pronation than the normal range. By contrast, only 3 (30%) of feet in the round head group had pronation greater than 16 degrees.

Conclusion:

In this surgical population of hallux valgus patients, the overall prevalence of excessive first metatarsal pronation was greater than in general cohorts of hallux valgus patients. Patients with intermediate and round shaped heads on plain radiographs tended to have greater first metatarsal pronation than those with angular shaped heads, although the correlation was not perfect. This suggests that plain radiographic assessment of metatarsal rotation may not be accurate as there may be discrepancies due to changes in foot position or angle of beam while acquiring the radiographs. Although further work is still required to determine whether there is clinical benefit from addressing the pronation, axial imaging (such as with WBCT) may be useful in the intermediate and round groups for accurate assessment of pronation and to determine if it is significant. This may be especially relevant in surgical candidates in whom osteotomies such as a scarf are being considered, where pronation cannot be addressed.

Rate of COVID-19 infection and 30 day mortality between blue and green (dedicated COVID-19 safe) pathways: Results from phase 1 and 2 of the UK foot and ankle COVID-19 national (UK-FAlCoN) audit

OBJECTIVES

The primary aim was to determine the differences in COVID-19 infection rate and 30-day mortality in patients undergoing foot and ankle surgery between different treatment pathways over the two phases of the UK-FALCON audit, spanning the first and second UK national lockdowns.

SETTING

This was an ambispective (retrospective Phase 1 and prospective Phase 2) national audit of foot and ankle procedures in the UK in 2020 completed between 13th January 2020 and 30th November 2020.

PARTICIPANTS

All adult patients undergoing foot and ankle surgery in an operating theatre during the study period were included from 46 participating centres in England, Scotland, Wales and Northern Ireland. Patients were categorised as either a green pathway (designated COVID-19 free) or blue pathway (no protocols to prevent COVID-19 infection).

RESULTS

10,846 patients were included, 6644 from phase 1 and 4202 from phase 2. Over the 2 phases the infection rate on a blue pathway was 1.07% (69/6470) and 0.21% on a green pathway (9/4280). In phase 1, there was no significant difference in the COVID-19 perioperative infection rate between the blue and green pathways in any element of the first phase (pre-lockdown (p = .109), lockdown (p = .923) or post-lockdown (p = .577)). However, in phase 2 there was a significant reduction in perioperative infection rate when using the green pathway in both the pre-lockdown (p < .001) and lockdown periods (Odd's Ratio 0.077, p < .001). There was no significant difference in COVID-19 related mortality between pathways.

CONCLUSIONS

There was a five-fold reduction in the perioperative COVID-19 infection rate when using designated COVID-19 green pathways over the whole study period; however the success of the pathways only became significant in phase 2 of the study, where there was a 13-fold reduction in infection rate. The study shows a developing success to using green pathways in reducing the risk to patients undergoing foot and ankle surgery.

Unlocking Long-Term Stability of Upconversion Nanoparticles with Biocompatible Phosphonate-Based Polymer Coatings

Achieving long-term (>3 months) colloidal stability of upconversion nanoparticles (UCNPs) in biologically relevant buffers has been a major challenge, which has severely limited practical implementation of UCNPs in bioimaging and nanomedicine applications. To address this challenge, nine unique copolymers formulations were prepared and evaluated as UCNP overcoatings. These polymers consisted of a poly(isobutylene-alt-maleic anhydride) (PIMA) backbone functionalized with different ratios and types of phosphonate anchoring groups and poly(ethylene glycol) (PEG) moieties. The syntheses were done as simple, one-pot nucleophilic addition reactions. These copolymers were subsequently coated onto NaYF₄:Yb³⁺,Er³⁺ UCNPs, and colloidal stability was evaluated in 1 × PBS, 10 × PBS, and other buffers. UCNP colloidal stability improved (up to 4 months) when coated with copolymers containing greater proportions of anchoring groups and higher phosphonate valences. Furthermore, small molecules could be conjugated to these overcoated UCNPs by use of copper-free click chemistry, as was done to demonstrate suitability for sensor and bioprobe development.

Cytochrome P450 monooxygenase-mediated tailoring of triterpenoids and steroids in plants

The cytochrome P450 monooxygenase (CYP) superfamily comprises hemethiolate enzymes that perform remarkable regio- and stereospecific oxidative chemistry. As such, CYPs are key agents for the structural and functional tailoring of triterpenoids, one of the largest classes of plant natural products with widespread applications in pharmaceuticals, food, cosmetics, and agricultural industries. In this review, we provide a full overview of 149 functionally characterised CYPs involved in the biosynthesis of triterpenoids and steroids in primary as well as in specialised metabolism. We describe the phylogenetic distribution of triterpenoid- and steroid-modifying CYPs across the plant CYPome, present a structure-based summary of their reactions, and highlight recent examples of particular interest to the field. Our review therefore provides a comprehensive up-to-date picture of CYPs involved in the biosynthesis of triterpenoids and steroids in plants as a starting point for future research.

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 UK foot and ankle COVID-19 national (FAlCoN) audit - Regional variations in COVID-19 infection and national foot and ankle surgical activity

AIMS

This paper details the impact of COVID-19 on foot and ankle activity in the UK. It describes regional variations and COVID-19 infection rate in patients undergoing foot and ankle surgery before, during and after the first national lock-down.

PATIENTS & METHODS

This was a multicentre, retrospective, UK-based, national audit on foot and ankle patients who underwent surgery between 13th January and 31st July 2020. Data was examined pre- UK national lockdown, during lockdown (23rd March to 11th May 2020) and post-lockdown. All adult patients undergoing foot and ankle surgery in an operating theatre during the study period included from 43 participating centres in England, Scotland, Wales and Northern Ireland. Regional, demographic and COVID-19 related data were captured.

RESULTS

6644 patients were included. In total 0.53% of operated patients contracted COVID-19 (n = 35). The rate of COVID-19 infection was highest during lockdown (2.11%, n = 16) and lowest after lockdown (0.16%, n = 3). Overall mean activity during lockdown was 24.44% of pre-lockdown activity with decreases in trauma, diabetic and elective foot and ankle surgery; the change in elective surgery was most marked with only 1.73% activity during lock down and 10.72% activity post lockdown as compared to pre-lockdown. There was marked regional variation in numbers of cases performed, but the proportion of decrease in cases during and after lockdown was comparable between all regions. There was also a significant difference between rates of COVID-19 and timing of peak, cumulative COVID-19 infections between regions with the highest rate noted in South East England (3.21%). The overall national peak infection rate was 1.37%, occurring during the final week of lockdown. General anaesthetic remained the most common method of anaesthesia for foot and ankle surgery, although a significant increase in regional anaesthesia was witnessed in the lock-down and post-lockdown periods.

CONCLUSIONS

National surgical activity reduced significantly for all cases across the country during lockdown with only a slow subsequent increase in elective activity. The COVID-19 infection rate and peaks differed significantly across the country.

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.

The Assessment of First Metatarsal Rotation in the Normal Adult Population Using Weightbearing Computed Tomography

BACKGROUND

The importance of the rotational profile of the first metatarsal is increasingly recognized in the surgical planning of hallux valgus. However, rotation in the normal population has only been measured in small series. We aimed to identify the normal range of first metatarsal rotation in a large series using weightbearing computed tomography (WBCT).

METHODS

WBCT scans were retrospectively analyzed for 182 normal feet (91 patients). Hallux valgus angle, intermetatarsal angle, anteroposterior/lateral talus-first metatarsal angle, calcaneal pitch, and hindfoot alignment angle were measured using digitally reconstructed radiographs. Patients with abnormal values for any of these measures and those with concomitant pathology, previous surgery, or hallux rigidus were excluded. Final assessment was performed on 126 feet. Metatarsal pronation (MPA) and α angles were measured on standardized coronal computed tomography slices. Pronation was recorded as positive. Intraobserver and interobserver reliability were assessed using intraclass correlation coefficients (ICCs).

RESULTS

Mean MPA was 5.5 ± 5.1 (range, -6 to 25) degrees, and mean α angle was 6.9 ± 5.5 (range, -5 to 22) degrees. When considering the normal range as within 2 standard deviations of the mean, the normal range identified was -5 to 16 degrees for MPA and -4 to 18 degrees for α angle. Interobserver and intraobserver reliability were excellent for both MPA (ICC = 0.80 and 0.97, respectively) and α angle (ICC = 0.83 and 0.95, respectively). There was a moderate positive correlation between MPA and α angle (Pearson coefficient 0.68, P < .001).

CONCLUSION

Metatarsal rotation is variable in normal feet. Normal MPA can be defined as less than 16 degrees, and normal α angle can be defined as less than 18 degrees. Both MPA and α angle are reproducible methods for assessing rotation. Further work is needed to evaluate these angles in patients with deformity and to determine their significance when planning surgical correction of hallux valgus.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

P–771 I hear, I forget. I see and I remember. I do and I understand. An Insight into the need for training for add on techniques

Study question

Do embryologists need additional training or certifications before using add on techniques in the lab ?

Summary answer

Out of 173 respondents majority feel add on techniques require training and/or certifications, the mode of training varies for different add ons.

What is known already

Cochrane reviews have suggested that minimal evidence exists for the use of add on treatments in ART, the data on the prevalence of add ons in IVF is unclear but the presence of technologies in ART laboratories world over suggests a increasing trend of adoption of unproven techniques. No data exists suggesting the role of embryologists in performing the Add on techniques and how their training or lack of, can impact patient safety. The most common method of training comes from the manufacturers and there is a lack of structured trainings for add on treatments worldover.

Study design, size, duration

An internet based survey was designed keeping in mind commonly available laboratory add ons. It comprised of 9 sections and a total of 18 multiple choice questions. Answer choices ranged from a simple yes or no to more complex choices suggesting the type of training and the potential benefits of training.

Participants/materials, setting, methods

The Survey includes results from 173 embryologists from india with varying degree of experience. Add ons included in the survey were Sperm DNA Fragmentation test, IMSI, PICSI, Microfluidics, MACS, Advanced culture media, Oocyte vitrification, Assisted hatching, Time Lapse imaging, spindle view and Electronic Witnessing. The most common practice suggestions were tabulated and identified.

Main results and the role of chance

The survey reports huge need for training for different add on treatments (SDF –91.4%, IMSI - 81.2%, PICSI- 66.5%, Microfluidics- 55.9%, MACS –55.3%, MicroTese- 86.9%, using advanced culture medias{Calcium ionophore- 73.4%, Hyaluronan rich media- 52.1%, growth cytokine rich media–48.5%, Theophylline for sperm motility–50.9%},oocyte Vitrification 85.5%, Assisted Hatching 75.4%, Time-lapse and Electronic witnessing 77.3%, Polarised microscopy for spindle assessment 73.5%). The Most preferred mode of training for more invasive procedures was Hands on training, followed by On the job training and validation followed by workshops(SDF- 62.6%, IMSI- 61%,PICSI–56.1%, MACS and Microfluidics 38.8%,microTese- 50.6%,Oocyte freezing 85.5%, assisted hatching 67.8%,Time-lapse and electronic witnessing 77.3%, Spindle view 73.5% ). The most preferred mode of training for non invasive procedures was Workshops and Observerships, followed by CME’s, followed by product Leaflets(44.4%,42.1%,13.5% respectively). The most common answer for the disadvantages of not being trained was unable to use the technology to its fullest potential(88.5%), whereas the most common answer for the benefit of being trained was better outcomes with said technologies(76.6%).

Limitations, reasons for caution

This study includes responses from embryologists who have varied levels of experience, while the need for training can be established based on these results, a junior level embryologist might answer the survey differently as compared to a senior or a lab director.

Wider implications of the findings: This is a first of its kind large survey, suggesting the need for training and validation from the perspective of the embryologist. This data can be used in formulating guidelines for future trainings and can help regulators in deciding on the most preferred mode of training.

Trial registration number

-

Pathological fracture in paediatric bone tumours and tumour-like lesions: A predictor of benign lesions?

OBJECTIVE

To determine the incidence and causes of pathological fractures in paediatric bone tumours and tumour-like lesions, and to determine if they are predictive of benign lesions.

METHODS AND MATERIALS

Retrospective review of children with suspected bone tumours referred to a specialist musculoskeletal oncology service between September 2019 and August 2020. Data recorded included patient age and gender, lesion location, the presence of a pathological fracture on the initial plain radiograph, and the final diagnosis made either by image-guided biopsy/curettage or based on typical imaging features.

RESULTS

231 patients were included with 233 lesions (138 males and 93 females with mean age 10.5 years, range 3 months-18 years). Final diagnosis was based on histology in 85 (36.5%) cases and imaging in 148 (63.5%) cases, 52 (22.3%) lesions classed as non-neoplastic, 139 (59.7%) as benign and 42 (18%) as malignant. Pathological fractures were seen in 41 cases (17.6%) at presentation, involving the humerus in 19 (46.3%), the femur in 14 (34.1%), the tibia in 3 (7.3%), the fibula and radius in two each (4.9%) and the second toe proximal phalanx in 1 (2.4%) (p < 0.001). The commonest underlying lesions included simple bone cyst (n = 17; 41.5%) and non-ossifying fibroma (n = 10; 24.4%). Only 4 cases (9.75%) were malignant, one case each of osteosarcoma, Ewing sarcoma, leukaemia and BCOR undifferentiated round cell sarcoma. Pathological fracture occurred in 27.7% of non-malignant lesions and 9.5% of malignant lesions, this difference being statistically significant (p < 0.001).

CONCLUSION

Pathological fractures were seen in 17.6% of paediatric bone tumours, tumour-like lesions, being significantly associated with humeral location and non-malignant diagnosis.

ADVANCES IN KNOWLEDGE

Demonstrates the frequency, location and underlying diagnosis of pathological fractures in paediatric bone tumour and tumour-like lesions.

The Assessment of First Metatarsal Rotation in the Normal Adult Population Using Weightbearing Computed Tomography

BACKGROUND

The importance of the rotational profile of the first metatarsal is increasingly recognized in the surgical planning of hallux valgus. However, rotation in the normal population has only been measured in small series. We aimed to identify the normal range of first metatarsal rotation in a large series using weightbearing computed tomography (WBCT).

METHODS

WBCT scans were retrospectively analyzed for 182 normal feet (91 patients). Hallux valgus angle, intermetatarsal angle, anteroposterior/lateral talus-first metatarsal angle, calcaneal pitch, and hindfoot alignment angle were measured using digitally reconstructed radiographs. Patients with abnormal values for any of these measures and those with concomitant pathology, previous surgery, or hallux rigidus were excluded. Final assessment was performed on 126 feet. Metatarsal pronation (MPA) and α angles were measured on standardized coronal computed tomography slices. Pronation was recorded as positive. Intraobserver and interobserver reliability were assessed using intraclass correlation coefficients (ICCs).

RESULTS

Mean MPA was 5.5 ± 5.1 (range, -6 to 25) degrees, and mean α angle was 6.9 ± 5.5 (range, -5 to 22) degrees. When considering the normal range as within 2 standard deviations of the mean, the normal range identified was -5 to 16 degrees for MPA and -4 to 18 degrees for α angle. Interobserver and intraobserver reliability were excellent for both MPA (ICC = 0.80 and 0.97, respectively) and α angle (ICC = 0.83 and 0.95, respectively). There was a moderate positive correlation between MPA and α angle (Pearson coefficient 0.68, P < .001).

CONCLUSION

Metatarsal rotation is variable in normal feet. Normal MPA can be defined as less than 16 degrees, and normal α angle can be defined as less than 18 degrees. Both MPA and α angle are reproducible methods for assessing rotation. Further work is needed to evaluate these angles in patients with deformity and to determine their significance when planning surgical correction of hallux valgus.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Comparison of in-phase and opposed-phase T1W gradient echo and T2W fast spin echo dixon chemical shift imaging for the assessment of non-neoplastic, benign neoplastic and malignant marrow lesions

OBJECTIVE

The objective of this study is to compare T1-weighted gradient echo (T1W GrE: control technique) chemical shift imaging (CSI) with T2-weighted fast spin echo (T2W FSE: experimental technique) CSI for differentiating non-neoplastic and neoplastic marrow lesions.

MATERIALS AND METHODS

Patients undergoing MRI for various marrow lesions were investigated with T1W GrE and T2W FSE Dixon CSI. Signal intensity (SI) change between in-phase (IP) and opposed-phase (OP) sequences was calculated, and SI drop > 20% considered to represent non-neoplastic lesions while SI drop < 20% considered to represent neoplastic lesions. Final diagnosis was based on imaging features (n = 42) or histology (n = 43) and classified as non-neoplastic, benign neoplastic, and malignant neoplastic. Inter-observer and inter-technique agreement between 2 readers was calculated.

RESULTS

The study included 85 patients (44 males and 41 females; mean age 41.1 years, range 2-83 years). Final diagnosis included 19 (22.4%) non-neoplastic lesions, 27 (31.8%) benign neoplasms, and 39 (45.9%) malignant neoplasms. On T1W GrE CSI, 19-21 lesions were classed as non-neoplastic and 64-66 as neoplastic, while on T2W FSE Dixon CSI, 22-24 lesions were classed as non-neoplastic and 61-64 as neoplastic. Lesion classification matched between the 2 techniques in 91.8-96.5% of cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of T1W GrE CSI for differentiating non-neoplastic and neoplastic marrow lesions were 66.7-72.2%, 88.1-89.6%, 61.9-63.2%, 90.9-92.2%, and 84.7%, and of T2W FSE Dixon CSI were 72.2-77.8%, 85.1-86.6%, 58.3-59.1%, 92.1-93.4%, and 83.5%.

CONCLUSIONS

T1W GrE CSI and T2W FSE Dixon CSI produce similar results in the assessment of non-neoplastic and neoplastic marrow lesions.

The incidence and relevance of non-fatty components in trunk and extremity lipomatous soft tissue masses

OBJECTIVES

To determine the incidence and diagnostic relevance of non-fatty 'solid appearing' components within lipomatous tumours of the trunk and extremity.

METHODS AND MATERIALS

Retrospective review of patients referred to a specialist musculoskeletal oncology service over a 12-month period with a lipomatous trunk or extremity soft tissue tumour. The presence and morphology (solitary/multifocal; homogeneous/heterogeneous; well-defined/poorly defined) of non-fatty components was recorded based on MRI and compared with the final histological diagnosis.

RESULTS

213 patients with 217 lipomatous tumours were included, 119 (55.9%) males and 94 (44.1%) females with mean age of 54.6 years (range 7-93 years). Seventy-seven (35.5%) lesions arose superficial to the fascia and 139 (64.1%) deep, while a single case involved both compartments. Mean maximal tumour dimension was 94.9 mm (range 12-288 mm). Non-fatty 'solid appearing' components were identified in 28 (12.9%) cases, of which eight were solitary and 20 were multifocal, six had homogeneous SI and 22 had heterogeneous SI, and eight had well-defined margins, while 20 had poorly defined margins. Histological diagnosis was available in 20 of the tumours containing non-fatty components, 16 of which were benign, two intermediate grade and two malignant (a dedifferentiated liposarcoma and a myxoid liposarcoma). The commonest diagnosis was spindle cell lipoma, which accounted for 10 of 20 (50%) cases with confirmed histology.

CONCLUSIONS

Non-fatty components are identified in ~13% of trunk and extremity lipomatous tumours. The majority of such lesions are benign lipoma variants, most commonly spindle cell lipoma.

ADVANCES IN KNOWLEDGE

Solid non-fatty components are identified in approximately 13% of lipomatous tumours referred to a specialist sarcoma service. Despite the concern that these may represent dedifferentiated liposarcomas, high-grade tumours were seen in only two cases, the commonest diagnosis being a spindle cell lipoma.

The UK Foot and Ankle COVID-19 National (FAlCoN) audit

Aims

The primary objective was to determine the incidence of COVID-19 infection and 30-day mortality in patients undergoing foot and ankle surgery during the global pandemic. Secondary objectives were to determine if there was a change in infection and complication profile with changes introduced in practice.

Methods

This UK-based multicentre retrospective national audit studied foot and ankle patients who underwent surgery between 13 January and 31 July 2020, examining time periods pre-UK national lockdown, during lockdown (23 March to 11 May 2020), and post-lockdown. All adult patients undergoing foot and ankle surgery in an operating theatre during the study period were included. A total of 43 centres in England, Scotland, Wales, and Northern Ireland participated. Variables recorded included demographic data, surgical data, comorbidity data, COVID-19 and mortality rates, complications, and infection rates.

Results

A total of 6,644 patients were included. Of the operated patients, 0.52% (n = 35) contracted COVID-19. The overall all-cause 30-day mortality rate was 0.41%, however in patients who contracted COVID-19, the mortality rate was 25.71% (n = 9); this was significantly higher for patients undergoing diabetic foot surgery (75%, n = 3 deaths). Matching for age, American Society of Anesthesiologists (ASA) grade, and comorbidities, the odds ratio of mortality with COVID-19 infection was 11.71 (95% confidence interval 1.55 to 88.74; p = 0.017). There were no differences in surgical complications or infection rates prior to or after lockdown, and among patients with and without COVID-19 infection. After lockdown the COVID-19 infection rate was 0.15% and no patient died of COVID-19.

Conclusion

COVID-19 infection was rare in foot and ankle patients even at the peak of lockdown. However, there was a significant mortality rate in those who contracted COVID-19. Overall surgical complications and postoperative infection rates remained unchanged during the period of this audit. Patients and treating medical personnel should be aware of the risks to enable informed decisions.

Cite this article: Bone Joint Open 2021;2(4):216–226.

The differential diagnosis of trunk and extremity dermal and sub-dermal lesions referred to a musculoskeletal oncology service

OBJECTIVES

To determine the differential diagnosis of dermal and sub-dermal soft tissue masses which do not extend to the deep fascia that are referred to a specialist musculoskeletal oncology service.

MATERIALS AND METHODS

Review of all patients referred to a specialist musculoskeletal oncology service over a 13-month period with a dermal or sub-dermal soft tissue mass which did not extend to the deep fascia based on MRI appearances. Data collected included age, gender, site and maximal lesion size, and final histological diagnosis for biopsied and/or excised lesions.

RESULTS

56 patients were included, 21 (37.5%) males and 35 (62.5%) females with mean age 49.75 years (range 5-86 years). 3 patients had 2 lesions making a total of 59 lesions, 11 (18.6%) dermal and 48 (81.4%) sub-dermal. Histological diagnosis was available in 44 (74.6%) cases, of which 11 (25%) were non-neoplastic, 23 (52.3%) were benign neoplasms, and 10 (22.7%) were malignant neoplasms. Although older age at presentation and greater mean maximal tumour dimension were seen with malignant lesions, these did not reach statistical significance (p = 0.154 and 0.102 respectively). There was also no relationship between skin involvement from sub-dermal lesions and malignancy, but 5 of 6 dermal lesions which showed an exophytic growth pattern were malignant.

CONCLUSIONS

The differential diagnosis of dermal and sub-dermal lesions which do not reach the deep fascia is wide with a malignant lesion being the cause in almost one-quarter of cases.

Tumours and tumour-like lesions of joints: Differential diagnoses in a paediatric population compared to adults

OBJECTIVE

To determine the differential diagnosis of intra-articular tumours and tumour-like lesions in a paediatric population compared to adults.

METHODS

Retrospective review of children up to the age of 18 years with suspected intra-articular tumours and tumour-like lesions referred to a specialist musculoskeletal oncology service from January 2019 to August 2020. Data recorded included patient age and gender, lesion location and morphology (based on the classification system of Adams et al.), and the final diagnosis made either by image-guided biopsy/resection or by clinical and imaging features. Comparison was then made with a group of adults presenting during the same period.

RESULTS

28 paediatric patients were included (12 males and 16 females with mean age 11.2 years, range 3-18 years). Joints involved were the knee (n = 22; 78.6%), ankle (n = 4; 14.3%), hip (n = 1; 3.6%) and elbow (n = 1; 3.6%). Lesion morphology was Type 1 (n = 18; 64.3%), Type 2 (n = 3; 10.7%), Type 3 (n = 1; 3.6%) and Type 4 (n = 5; 17.9%). Final diagnosis was made by image-guided biopsy/resection in 18 (64.3%) patients. The commonest neoplastic lesion was tenosynovial giant cell tumour (n = 11; 39.3%), followed by synovial haemangioma (n = 5; 17.9%). There was only a single malignant lesion, a case of synovial sarcoma. Of eight (28.6%) non-neoplastic lesions, three were diagnosed as juvenile idiopathic arthritis and three as non-specific synovitis. There was no difference compared to adults regarding gender, joint involved or lesion morphology, but there was a significant difference in final diagnoses (p < 0.001). The range of intra-articular tumours and tumour-like lesions in children differs from that in adults, although tenosynovial giant cell tumour is the commonest diagnosis in both groups and malignant lesions are rare.

ADVANCES IN KNOWLEDGEART

In our series, ~16% of tumours and tumour-like lesions of joints occur in the paediatric population. Tenosynovial giant cell tumour remains the commonest diagnosis in children as in adults. Synovial haemangioma and juvenile idiopathic arthritis were the next commonest diagnoses in children, while primary synovial chondromatosis and reactive synovitis were the next commonest diagnoses in adults. Malignant lesions are rare in both groups.

Salvage Tibiotalocalcaneal Arthrodesis Augmented With Fibular Columns and Iliac Crest Autograft: A Technical Note

Failure of ankle arthrodesis or total ankle replacement (TAR) results in a challenging clinical situation and may take the form of symptomatic nonunion following arthrodesis and aseptic or infective loosening following TAR. Revision in these scenarios is technically demanding, and if associated with subtalar degeneration, conversion to tibiotalocalcaneal (TTC) arthrodesis may be required, with use of bone grafting to maintain length and reduce disability. Fibular strut grafting in the form of pillars or columns, potentially supplemented by tricortical and iliac graft, may be used in association with intramedullary TTC nailing or lateral plating and has demonstrated encouraging fusion rates. In this technical note, we review the history of this technique and report indications and surgical approach. Furthermore, of 6 cases (mean age 69.8 years) treated at our institution and followed at 13 months (range, 8 to 20 months), 5 (83%) were clinically and radiologically united, and patients were satisfied with the outcome of surgery. One patient with a background of chronic kidney disease remained dissatisfied with no union achieved, persistent pain, and awaiting a below-the-knee amputation. No other complications were observed. TTC fusion augmented with fibular columns and iliac crest autograft is an option to treat combined ankle and subtalar joint pathologies with significant talar bone loss.Levels of Evidence: Level V (technical note).

Mechanical and anatomical axis of the lower limb in total ankle arthroplasty

INTRODUCTION

Inadequate correction of mechanical alignment may lead to failure of Total Ankle Replacements (TAR). The mechanical axis of the lower limb (MAL), the mechanical axis of the tibia (MAT) and the anatomical axis of the tibia (AAT) are three well described coronal plane measurements using plain radiography. The assumption is that the MAL, MAT and AAT are equivalent. The relationship between these axes can vary in the presence of proximal deformity. The purpose of this study was to assess the relationship between MAL, MAT and AAT in a cohort of patients considered for TAR.

METHODS

75 consecutive standardised preoperative long leg radiographs of patients with end stage ankle osteoarthritis, between 2016 and 2017 at a specialist tertiary center for elective orthopedic surgery were analysed. Patients were split into 2 groups. The first group had a clinically and radiologically detectable deformity proximal to the ankle (such as previous tibial or femoral fracture, severe arthritis, or previous reconstructive surgery), whereas the second (normal) group did not. The MAL, MAT and AAT were measured and the difference between these values were calculated.

RESULTS

There were 54 patients in the normal group, and 21 patients in the deformity group. The mean difference between the MAL and AAT was 1.7 ± 1.3° (range, 0.1-5.4°). In the normal group, 15 patients (27%) had a difference of >2° between the MAL and AAT, compared with 52% in the deformity group. The mean difference between the MAL and MAT was 0.9 ± 1.7° (range, -4 to -3.5°). In the deformity group, 42% of patients had a difference between MAT and MAL of >2°, compared with 20% in the normal group.

CONCLUSION

MAT, MAL and AAT should not be assumed to be the same in all patients. The authors recommend considering the use of full-length weightbearing lower limb radiographs to plan TAR.

Early results of minimally invasive, reverse-oblique, distal metaphyseal metatarsal osteotomy (R-DMMO) for arthritis of the lesser tarsometatarsal joints - A retrospective case series

BACKGROUND

Arthrodesis is the gold standard for operative management of osteoarthritis of the lesser tarsometatarsal joints (TMTJs) but is not without complications. Our early results of a minimally invasive alternative treatment - the reverse-oblique distal metaphyseal metatarsal osteotomy (R-DMMO) are described.

METHODS

This is a single-centre, single-surgeon, retrospective series of patients with isolated, symptomatic lesser TMTJ arthrosis who underwent R-DMMO.

RESULTS

Sixteen feet in 15 patients were included. The mean age was 64.7±9.7 years and mean duration of follow-up was 109.4±27.4 weeks. There were no non-unions, infections or wound complications. Two patients developed transfer symptoms to their first metatarsal, one of these patients improved after three months. There was one delayed union which united at 12 months. Two patients developed recurrence of symptoms but felt that they were still improved compared to preoperatively and no patient has required arthrodesis thus far. The mean preoperative VAS was 8.3±1.3 and the mean postoperative VAS was 2.4±2.2 (P<0.001). The mean postoperative MOxFQ-Walking was 25.2±25.6, MOxFQ-Pain was 24.8±20.5, MOxFQ-Social was 18.4±19.1, and MOxFQ-Index was 23.4±20.6. Eight patients were 'very satisfied' and seven were 'satisfied' with the procedure.

CONCLUSIONS

R-DMMO is a minimally invasive and safe procedure for lesser TMTJ arthrosis which can produce good results and prevent, or at least delay, the need for arthrodesis without compromising future operative options. Good to excellent outcomes have been shown with few significant complications in the short term in selected patients.

Vitamin D in the Foot and Ankle: A Review of the Literature

BACKGROUND

Vitamin D is an essential vitamin that targets several tissues and organs and plays an important role in calcium homeostasis. Vitamin D deficiency is common, particularly at higher latitudes, where there is reduced exposure to ultraviolet B radiation. We reviewed the role of vitamin D and its deficiency in foot and ankle pathology.

METHODS

The effects of vitamin D deficiency have been extensively studied, but only a small portion of the literature has focused on the foot and ankle. Most evidence regarding the foot and ankle consists of retrospective studies, which cannot determine whether vitamin D deficiency is, in fact, the cause of the pathologies being investigated.

RESULTS

The available evidence suggests that insufficient vitamin D levels may result in an increased incidence of foot and ankle fractures. The effects of vitamin D deficiency on fracture healing, bone marrow edema syndrome, osteochondral lesions of the talus, strength around the foot and ankle, tendon disorders, elective foot and ankle surgery, and other foot and ankle conditions are less clear.

CONCLUSIONS

Based on the available evidence, we cannot recommend routine testing or supplementation of vitamin D in patients with foot and ankle pathology. However, supplementation is cheap, safe, and may be of benefit in patients at high risk for deficiency. When vitamin D is supplemented, the evidence suggests that calcium should be co-supplemented. Further high-quality research is needed into the effect of vitamin D in the foot and ankle. Cost-benefit analyses of routine testing and supplementation of vitamin D for foot and ankle pathology are also required.

Intravenous thrombolysis for large vessel or distal occlusions presenting with mild stroke severity

BACKGROUND AND PURPOSE

We investigated the effectiveness of intravenous thrombolysis (IVT) in acute ischaemic stroke (AIS) patients with large vessel or distal occlusions and mild neurological deficits, defined as National Institutes of Health Stroke Scale scores < 6 points.

METHODS

The primary efficacy outcome was 3-month functional independence (FI) [modified Rankin Scale (mRS) scores 0-2] that was compared between patients with and without IVT treatment. Other efficacy outcomes of interest included 3-month favorable functional outcome (mRS scores 0-1) and mRS score distribution at discharge and at 3 months. The safety outcomes comprised all-cause 3-month mortality, symptomatic intracranial hemorrhage (ICH), asymptomatic ICH and severe systemic bleeding.

RESULTS

We evaluated 336 AIS patients with large vessel or distal occlusions and mild stroke severity (mean age 63 ± 15 years, 45% women). Patients treated with IVT (n = 162) had higher FI (85.6% vs. 74.8%, P = 0.027) with lower mRS scores at hospital discharge (P = 0.034) compared with the remaining patients. No differences were detected in any of the safety outcomes including symptomatic ICH, asymptomatic ICH, severe systemic bleeding and 3-month mortality. IVT was associated with higher likelihood of 3-month FI [odds ratio (OR), 2.19; 95% confidence intervals (CI), 1.09-4.42], 3-month favorable functional outcome (OR, 1.99; 95% CI, 1.10-3.57), functional improvement at discharge [common OR (per 1-point decrease in mRS score), 2.94; 95% CI, 1.67-5.26)] and at 3 months (common OR, 1.72; 95% CI, 1.06-2.86) on multivariable logistic regression models adjusting for potential confounders, including mechanical thrombectomy.

CONCLUSIONS

Intravenous thrombolysis is independently associated with higher odds of improved discharge and 3-month functional outcomes in AIS patients with large vessel or distal occlusions and mild stroke severity. IVT appears not to increase the risk of systemic or symptomatic intracranial bleeding.

360-Degree Complex Primary Reconstruction Using Porous Tantalum Cages for Adult Degenerative Spinal Deformity

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess both implant performance and the amount of correction that can be achieved using multilevel anterior lumbar interbody fusion (ALIF).

METHODS

Retrospective cohort study (n = 178) performed over a 4-year period. Surgical variables examined included blood loss, operative time, perioperative complications, and secondary/revision procedures. Follow-up radiographic assessment was performed to record implant-related problems. Radiographic parameters were examined pre- and postoperatively. Health-related quality of life (HRQOL) outcome measures were collected preoperatively and at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Descriptive and comparative statistical analysis, using paired-sample t test and repeated-measures analysis of variance (rANOVA), was performed.

RESULTS

Lumbar lordosis increased from 42° ± 17° preoperatively to 55° ± 11° postoperatively (P < .001). The visual analog scale back pain mean score improved from 8.3 ± 1.5 preoperatively to 2.6 ± 2.4 at 2 years (P < .001). The mean Oswestry Disability Index improved from 69.5 ± 21.5 preoperatively to 19.9 ± 15.2 at 2 years (P < .001). The EQ-5D mean score improved from 0.2 ± 0.2 preoperatively to 0.8 ± 0.1 at 2 years (P = .02). There were no neurological, vascular, or visceral approach-related injuries reported. No rod breakages and no symptomatic nonunions occurred. There was one revision procedure performed for fracture.

CONCLUSIONS

The use of porous tantalum cages as part of a 360-degree fusion to treat adult degenerative spinal deformity has been demonstrated to be a safe and effective strategy, leading to good clinical, functional, and radiographic outcomes in the short term.

Gastrocnemius tightness: A population based observational study

BACKGROUND

Gastrocnemius tightness is believed to be associated with multiple musculoskeletal pathologies such as back pain, plantar fasciitis and metatarsalgia. Although surgical treatment of gastrocnemius tightness is gaining popularity the objective definition of a gastrocnemius contracture has not been determined. The aim of our study was therefore to quantify gastrocnemius tightness in a normal population.

METHODS

Adult participants with no obvious foot and ankle pathology were recruited. Gastrocnemius tightness was quantified using a weightbearing lunge test. Maximal ankle-foot dorsiflexion was measured on participants with the knee in full extension and flexed to 20° using a digital inclinometer. The ankle-foot dorsiflexion index or ADI (difference in ankle dorsiflexion with the knee extended and flexed) was calculated. The ADI values were plotted on a histogram to identify the distribution of values and were compared according to participant demographics.

RESULTS

800 limbs from 400 participants were examined. There was a wide distribution of absolute values of maximal ankle-foot dorsiflexion ranging from 8 to 52°. The ADI ranged from 0 to19° and approximated to a normal distribution. The mean ADI was 6.04±3.49° and was positively correlated with age (r=0.132, P<0.001) and negatively correlated with physical activity (r=-0.88, P=0.015).

CONCLUSION(S)

Our study is the first to quantify gastrocnemius tightness in a large healthy adult population with differences observed by age and physical activity. We have defined an easy and reproducible weightbearing test that can be used in both research and clinical settings. The majority of the population have some degree of gastrocnemius tightness and values of ADI greater than 13° (>2 SD of the mean), as measured by the lunge test, may be considered abnormal.

The effects of weight bearing on the distal tibiofibular syndesmosis: A study comparing weight bearing-CT with conventional CT

BACKGROUND

Syndesmotic injures are common and weight bearing imaging studies are often advocated to assess disruption. Although studies have examined the anatomical relationship between the fibula and incisura, the effect of weight-bearing on the syndesmosis has not been well reported. We characterise the changes which occur at the syndesmosis during weight-bearing.

METHODS

In this retrospective review we analysed the position of the fibula at the syndesmosis in a cohort of patients who underwent both non-weight-bearing and weight-bearing CT scans. The relative position of the fibula to the incisura was analysed to determine translation and rotation in the axial plane.

RESULTS

26 patients were included. Comparison of measurements revealed statistically significant differences between groups which indicated that on weight-bearing the fibula translated laterally and posteriorly, and rotated externally with respect to the incisura.

CONCLUSIONS

This is the first study to measure the differences in position of the syndesmosis during weight-bearing in a population of patients that have undergone both weight bearing and non weight bearing CT. Our study confirms that weight-bearing results in lateral and posterior translation, and external rotation of the fibula in relation to the incisura and our findings should help in future studies looking at the effect of weight bearing on syndesmotic pathology.

The Bologna-Oxford ankle replacement: a case series of clinical and radiological outcomes

PURPOSE

The Bologna-Oxford (BOX®) total ankle arthroplasty (TAA) is a three-component mobile-bearing implant gaining popularity in Europe. We aimed to analyse the outcomes of this TAA.

METHODS

We retrospectively analysed data on 34 consecutive BOX® TAAs performed at a single centre with a mean follow-up of 58 months. Radiographic outcomes, such as periprosthetic lucency and alignment, were measured and recorded. Prospectively captured clinical scores and range of movement (ROM) were also recorded.

RESULTS

There were significant improvements in patient-reported outcome scores recorded in the Manchester-Oxford Foot Questionnaire (MOxFQ) for pain (43.8 ± 20.2, p < 0.001), standing and walking (55.6 ± 19.8, p < 0.001), social activities (45.0 ± 26.9, p < 0.02) and visual analogue score (VAS) (3.1 ± 2.5, p < 0.001). Mean improvement in ROM postoperatively was 18.7° (p < 0.001), with post-operative dorsiflexion 8.8° (10°-25°) and plantar flexion 32.6° (20°-40°). There was evidence of asymptomatic lucency on five radiographs (15%), which was present in 10% at three years. Nine patients had complications (26%): six (18%) requiring secondary surgery and one requiring revision (3%) for infection.

CONCLUSIONS

We have demonstrated 97% survivorship at a mean of 58 months. There are maintained improvements in clinical and radiological outcomes and reoperation that are consistent with the literature.

Validation of leaf enzymes in the detergent and textile industries: launching of a new platform technology

Chemical catalysts are being replaced by biocatalysts in almost all industrial applications due to environmental concerns, thereby increasing their demand. Enzymes used in current industries are produced in microbial systems or plant seeds. We report here five newly launched leaf-enzyme products and their validation with 15 commercial microbial-enzyme products, for detergent or textile industries. Enzymes expressed in chloroplasts are functional at broad pH/temperature ranges as crude-leaf extracts, while most purified commercial enzymes showed significant loss at alkaline pH or higher temperature, required for broad range commercial applications. In contrast to commercial liquid enzymes requiring cold storage/transportation, chloroplast enzymes as a leaf powder can be stored up to 16 months at ambient temperature without loss of enzyme activity. Chloroplast-derived enzymes are stable in crude-leaf extracts without addition of protease inhibitors. Leaf lipase/mannanase crude extracts removed chocolate or mustard oil stains effectively at both low and high temperatures. Moreover, leaf lipase or mannanase crude-extracts removed stain more efficiently at 70 °C than commercial microbial enzymes (<10% activity). Endoglucanase and exoglucanase in crude leaf extracts removed dye efficiently from denim surface and depilled knitted fabric by removal of horizontal fibre strands. Due to an increased demand for enzymes in the food industry, marker-free lettuce plants expressing lipase or cellobiohydrolase were created for the first time and site-specific transgene integration/homoplasmy was confirmed by Southern blots. Thus, leaf-production platform offers a novel low-cost approach by the elimination of fermentation, purification, concentration, formulation and cold-chain storage/transportation. This is the first report of commercially launched protein products made in leaves and validated with current commercial products.

Detection of cystic fibrosis transmembrane conductance regulator ΔF508 gene mutation using a paper-based nucleic acid hybridization assay and a smartphone camera

Diagnostic technology that makes use of paper platforms in conjunction with the ubiquitous availability of digital cameras in cellular telephones and personal assistive devices offers opportunities for development of bioassays that are cost effective and widely distributed. Assays that operate effectively in aqueous solution require further development for implementation in paper substrates, overcoming issues associated with surface interactions on a matrix that offers a large surface-to-volume ratio and constraints on convective mixing. This report presents and compares two related methods for determination of oligonucleotides that serve as indicators of cystic fibrosis, differentiating between the normal wild-type sequence, and a mutant-type sequence that has a 3-base replacement. The transduction strategy operates by selective hybridization of oligonucleotide probes that are conjugated to fluorescent quantum dots, where hybridization of target sequences causes a molecular fluorophore to approach the quantum dot and become emissive through fluorescence resonance energy transfer. Detection can rely on hybridization of a target that is labelled with Cy3 fluorophore, or in the presence of an unlabelled target when a sandwich assay format is implemented with a labelled reporter oligonucleotide. Selectivity to determine the presence of mismatched sequences involves appropriate selection of nucleotide sequences to set melt temperatures, in conjunction with control of stringency conditions using formamide as a chaotrope. It was determined that both direct and sandwich assays on paper substrates are able to distinguish between wild-type and mutant-type samples.

Minimally invasive distal metaphyseal metatarsal osteotomy (DMMO) for symptomatic forefoot pathology - Short to medium term outcomes from a retrospective case series

BACKGROUND

Minimally invasive distal metaphyseal metatarsal osteotomy (DMMO) may be used to treat metatarsalgia and forefoot pathology. Few large series report its results or examine the degree of metatarsal shortening with this technique. The clinical and radiographic results of a cohort of patients treated with DMMOs at our unit are reported.

METHODS

This was a single-centre retrospective study looking at the outcome of consecutive patients undergoing DMMOs. Demographics, radiological and clinical outcomes, complications and patient reported outcome measures (PROMs) were analysed.

RESULTS

DMMOs on 106 toes in 43 feet were included. Mean age was 60.2±10.2 years and median follow-up was 38 months. Concurrent procedures were performed in 26 cases (60%). DMMO was performed on multiple toes in 42 cases (97%). Mean shortening achieved was 3.6±2.2mm, 4.1±1.6mm, and 3.6±1.6mm for the second, third and fourth metatarsals respectively. Mean time to fusion was 11.4±7.8 weeks and union occurred in 105 toes (99%). The single non-union was asymptomatic at 12 months. Two patients required a subsequent additional DMMO for transfer metatarsalgia. Minor complications were seen in 11 patients (26%). At final follow-up PROMs data was available for 42 cases: mean MOxFQ was 28.8±27.6, mean EQ-5D was 0.789±0.225, mean EQ-VAS was 68.5±20.3, mean VAS-Pain score was 3.1±2.8, and patients were satisfied overall in 40 cases (95%).

CONCLUSIONS

The authors demonstrate excellent radiological and clinical outcomes in the short to medium term with DMMOs and present data on metatarsal shortening achieved with this technique.

Defining reference values for the normal tibiofibular syndesmosis in adults using weight-bearing CT

Aims

Cone beam CT allows cross-sectional imaging of the tibiofibular syndesmosis while the patient bears weight. This may facilitate more accurate and reliable investigation of injuries to, and reconstruction of, the syndesmosis but normal ranges of measurements are required first. The purpose of this study was to establish: 1) the normal reference measurements of the syndesmosis; 2) if side-to-side variations exist in syndesmotic anatomy; 3) if age affects syndesmotic anatomy; and 4) if the syndesmotic anatomy differs between male and female patients in weight-bearing cone beam CT views.

Patients and Methods

A retrospective analysis was undertaken of 50 male and 50 female patients (200 feet) aged 18 years or more, who underwent bilateral, simultaneous imaging of their lower legs while standing in an upright, weight-bearing position in a pedCAT machine between June 2013 and July 2017. At the time of imaging, the mean age of male patients was 47.1 years (18 to 72) and the mean age of female patients was 57.8 years (18 to 83). We employed a previously described technique to obtain six lengths and one angle, as well as calculating three further measurements, to provide information on the relationship between the fibula and tibia with respect to translation and rotation.

Results

The upper limit of lateral translation in un-injured patients was 5.27 mm, so values higher than this may be indicative of syndesmotic injury. Anteroposterior translation lay within the ranges 0.31 mm to 2.59 mm, and -1.48 mm to 3.44 mm, respectively. There was no difference between right and left legs. Increasing age was associated with a reduction in lateral translation. The fibulae of men were significantly more laterally translated but data were inconsistent for rotation and anteroposterior translation.

Conclusion

We have established normal ranges for measurements in cross-sectional syndesmotic anatomy during weight-bearing and also established that no differences exist between right and left legs in patients without syndesmotic injury. Age and gender do, however, affect the anatomy of the syndesmosis, which should be taken into account at time of assessment. Cite this article: Bone Joint J 2019;101-B:348–352.