Biomechanical Effects of Hindfoot Alignment in Supination External Rotation Malleolar Fractures: A Human Cadaveric Model

BACKGROUND

Pressure distribution in the ankle joint is known to be dependent on various factors, including hindfoot alignment. We seek to evaluate how hindfoot alignment affects contact pressures in the ankle joint in the setting of supination external rotation (SER) type ankle fractures.

METHODS

SER fractures were created in 10 human cadaver lower extremity specimens, simulating progressive stages of injury: without fracture (step 0), SER fracture and intact deltoid ligament (step 1), superficial deltoid ligament disruption (step 2), and deep deltoid ligament disruption (step 3). At each step, varus and valgus alignment was simulated by displacing the calcaneal tuberosity 7 mm medial or lateral. Each limb was axially loaded following each osteotomy at a static load of 350 N. The center of force (COF), contact area (CA), and peak contact pressure (PP) under load were measured, and radiographs of the ankle mortise were taken to analyze the medial clear space (MCS) and talar tilt (TT).

RESULTS

The COF (5.3 mm, P = .030) and the CA (-188.4 mm2, P = .015) changed in step 3 in the valgus hindfoot alignment compared to baseline parameters, indicating the importance of deep deltoid ligament integrity in maintaining normal ankle joint contact stress in the valgus hindfoot. These changes were not seen in the setting of varus alignment (COF: 2.3 mm, P = .059; CA -121 mm2, P = .133). PP were found to not change significantly in either varus or valgus (varus: -4.9 N, P = .132; valgus: -4 N, P = .464).The MCS demonstrated widening in step 3 compared to step 2 (0.7 mm, P = .020) in both varus and valgus hindfoot. The TT increased significantly in step 3 in the valgus hindfoot (2.8 degrees, P = .020) compared to step 0.

CONCLUSION

SER-IV fractures with valgus hindfoot alignment showed significant changes in pressure distribution and radiographic parameters when compared to SER-IV fractures with varus hindfoot alignment.

CLINICAL RELEVANCE

Based on this cadaver modeling study, patients with SERIV fracture with varus hindfoot alignment and complete deltoid ligament lesion may not need fracture fixation, whereas those with valgus hindfoot alignment likely need fracture fixation.

Recurrence Rate After Wide Resection of Plantar Fibromatosis: A Case Series and Systematic Literature Review

BACKGROUND

The aim was to assess the recurrence rate and clinical outcome after wide resection for plantar fibromatosis.

METHODS

A total of 12 patients, 2 to 13 years after wide resection, were assessed for local and magnetic resonance imaging tomographic signs of recurrence at the clinical follow-up. In addition, a systematic review of the literature was conducted.

RESULTS

After 7.8 years (2-13), 2 patients (17%) suffered a recurrence. At the last follow-up, median Foot Functional Index was 1 (0-66) and American Orthopaedic Foot and Ankle Society score was 95 (44-100). Six studies with 109 feet (92 patients) were included in the systematic review. The recurrence rate depends on the width of the resection: 67% after local resection, 42% after wide resection, and 27% after fasciectomy.

CONCLUSION

In patients with symptomatic plantar fibromatosis, we recommend a wide resection or fasciectomy over a local resection because of the inferior recurrence rate.

LEVELS OF EVIDENCE

Level IV: Retrospective case series.

iNClusive: a database collecting useful information on non-canonical amino acids and their incorporation into proteins for easier genetic code expansion implementation

The incorporation of non-canonical amino acids (ncAAs) into proteins is a powerful technique used in various research fields. Genetic code expansion (GCE) is the most common way to achieve this: a specific codon is selected to be decoded by a dedicated tRNA orthogonal to the endogenous ones. In the past 30 years, great progress has been made to obtain novel tRNA synthetases (aaRSs) accepting a variety of ncAAs with distinct physicochemical properties, to develop robust in vitro assays or approaches for codon reassignment. This sparked the use of the technique, leading to the accumulation of publications, from which gathering all relevant information can appear daunting. Here we present iNClusive (https://non-canonical-aas.biologie.uni-freiburg.de/), a manually curated, extensive repository using standardized nomenclature that provides organized information on ncAAs successfully incorporated into target proteins as verified by mass spectrometry. Since we focused on tRNA synthetase-based tRNA loading, we provide the sequence of the tRNA and aaRS used for the incorporation. Derived from more than 687 peer-reviewed publications, it currently contains 2432 entries about 466 ncAAs, 569 protein targets, 500 aaRSs and 144 tRNAs. We foresee iNClusive will encourage more researchers to experiment with ncAA incorporation thus contributing to the further development of this exciting technique.

Arm-support exoskeleton reduces shoulder muscle activity in ceiling construction

The objective of this study was to assess the efficacy and user's impression of an arm-support exoskeleton in complex and realistic ceiling construction tasks. 11 construction workers performed 9 tasks. We determined objective and subjective efficacy of the exoskeleton by measuring shoulder muscle activity and perceived exertion. User's impression was assessed by questionnaires on expected support, perceived support, perceived hindrance and future intention to use the exoskeleton. Wearing the exoskeleton yielded persistent reductions in shoulder muscle activity of up to 58% and decreased perceived exertion. Participants reported limited perceived hindrance by the exoskeleton, as also indicated by no increase in antagonistic muscle activity. The findings demonstrate the high potential of an arm-support exoskeleton for unloading the shoulder muscles when used in the dynamic and versatile working environment of a ceiling construction worker, which is in line with the consistent intention of the workers to use the exoskeleton in the future.Practitioner Summary: The majority of research focuses on the effect of using an arm-support exoskeleton during isolated postures and prescribed movements. We investigated the efficacy of an exoskeleton during a complex and realistic work, namely ceiling construction. Shoulder muscle activity was lower in almost all tasks when wearing the exoskeleton.

ReverseDock: a web server for blind docking of a single ligand to multiple protein targets using AutoDock Vina

Several platforms exist to perform molecular docking to computationally predict binders to a specific protein target from a library of ligands. The reverse, that is, docking a single ligand to various protein targets, can currently be done by very few web servers, which limits the search to a small set of pre-selected human proteins. However, the possibility to in silico predict which targets a compound identified in a high-throughput drug screen bind would help optimize and reduce the costs of the experimental workflow needed to reveal the molecular mechanism of action of a ligand. Here, we present ReverseDock, a blind docking web server based on AutoDock Vina specifically designed to allow users with no computational expertise to dock a ligand to 100 protein structures of their choice. ReverseDock increases the number and type of proteins a ligand can be docked to, making the task of in silico docking of a ligand to entire families of proteins straightforward. We envision ReverseDock will support researchers by providing the possibility to apply inverse docking computations using web browser. ReverseDock is available at: https://reversedock.biologie.uni-freiburg.de/.

Quo vadis, foot & ankle research? A review

Over the last two decades, there has been a growing emphasis on the publication quality in Foot & Ankle research. A level-of-evidence rating system for clinical scientific papers has been proposed by the Centre for Evidence-based medicine in Oxford, United Kingdom. As opposed to other subspecialities, foot & ankle surgery deals with a wide variety of clinical problems and surgical solutions, which in turn leads to a generally low number of patients available for study groups. However, level III and IV studies still have a valuable place in orthopaedic research, given the challenges in running high-level studies.The measurement of outcomes in medicine from the patients' perspective (PROMS:(patient reported outcome measures) has grown almost exponentially in all surgical specialties including foot & ankle surgery. There are many PROMs available to foot & ankle surgeons, but there is little consensus on which assessment is most appropriate for a given procedure or diagnosis. Their use in research and clinical practice offers many advantages in clinical practice and research, however, besides the advantages there are also some downsides.

Risk Factors for Failure After Surgery in Patients With Diabetic Foot Syndrome

Background

In the present study, we aimed to identify risk factors for failure (defined as reoperation within 60 days) after debridement or amputation at the lower extremity in patients with diabetic foot syndrome and to develop a model using the significant risk factors to predict the success rate at different levels of amputation.

Methods

Between September 2012 and November 2016, we performed a prospective observational cohort study of 174 surgeries in 105 patients with diabetic foot syndrome. In all patients, debridement or the level of amputation, need for reoperation, time to reoperation, and potential risk factors were assessed. A cox regression analysis, dependent on the level of amputation, with the endpoint reoperation within 60 days defined as failure and a predictive model for the significant risk factors were conducted.

Results

We identified the following 5 independent risk factors: More than 1 ulcer (hazard ratio [HR] 3.8), peripheral artery disease (PAD, HR 3.1), C-reactive protein >100 mg/L (HR 2.9), diabetic peripheral neuropathy (HR 2.9), and nonpalpable foot pulses (HR 2.7) are the 5 independent risk factors for failure, which were identified. Patients with no or 1 risk factor have a high success rate independent of the level of amputation. A patient with up to 2 risk factors undergoing debridement will achieve a success rate of <60%. However, a patient with 3 risk factors undergoing debridement will need further surgery in >80%. In patients with 4 risk factors a transmetatarsal amputation and in patients with 5 risk factors a lower leg amputation is needed for a success rate >50%.

Conclusion

Reoperation for diabetic foot syndrome occurs in 1 of 4 patients. Risk factors include presence of more than 1 ulcer, PAD, CRP > 100, peripheral neuropathy, and nonpalpable foot pulses. The more risk factors are present, the lower the success rate at a certain level of amputation.

Level of Evidence

Level II, prospective observational cohort study.

Malleolarfrakturen

Zusammenfassung. Für das Verständnis des Unfallmechanismus und des zu erwartenden Verletzungsmusters teilt man Malleolarfrakturen bevorzugt nach der Lauge-Hansen-Klassifikation ein [1]. Für die isolierten lateralen Malleolarfrakturen wird zudem häufig die Klassifikation nach Weber verwendet [2]. Eine konservative Therapie ist für die meisten Weber-A-Frakturen und ca. 80% der Weber-B-Frakturen indiziert. Handelt es sich um eine isolierte Weber-B-Fraktur, sollte nach Lauge-Hansen zunächst zwischen einer Supinations-Aussenrotations-Verletzung (SER) und einer Pronations-Abduktions-Verletzung (PA) unterschieden werden. Bei den SER-Frakturen ist die Stabilität mit einer «Gravity Stress»-Aufnahme und einer stehenden Röntgenaufnahme zu testen. Ist die Fraktur stabil, kann diese problemlos konservativ behandelt werden. Die operative Therapie empfehlen wir bei instabilen Weber-B-SER-Verletzungen, Weber-B-PA-Verletzungen und Weber-C-Frakturen.

Osteochondral lesion of the talus: still a problem?

Osteochondral lesion of the talus (OLT) often occurs after ankle trauma or repetitive micro-traumata, whereas the actual etiology remains unclear. The most common symptoms are local pain deep in the medial or lateral ankle that increases with weight-bearing and activity, accompanied by tenderness and swelling.

Eventually, most patients with symptomatic or unstable OLT require surgery. Many reasonable operative techniques have been described, whereas most lead to similar and satisfactory results. They can be divided into cartilage repair, cartilage regeneration and cartilage replacement techniques. The OLT size and morphology in the first place but also surgeon and individual patient aspects are considered when it comes to surgery.

For high postoperative success and low recurrence rates, underlying causes, for example, ligamentous instability and hindfoot malalignment should also be addressed during surgery.

What about the human in human robot collaboration?

In this review we address the human in human robot collaboration (HRC). Although there are different hypotheses on potential effects of HRC on job quality, defined as the quality of the working environment and its effect on the employee's well-being, a comprehensive theory is still lacking. How does HRC influence job quality on an individual level and how can we adapt HRC to boost positivity at work? We identified four job quality related factors that are of relevance in HRC: (1) Cognitive Workload, (2) Collaboration Fluency, (3) Trust, and (4) Acceptance and Satisfaction. Increasing awareness and being able to adapt the robot to the individual operator are crucial to improve the aforementioned factors. Implementing predictable robots, that offer a clear advantage to the human and take into account operators' preferences, will bring us closer to a human-centered collaboration. Practitioner Summary: The effect of human robot collaboration (HRC) on job quality is still under debate. Design characteristics of HRC, such as collaboration design, robot design, and workplace design affect job quality related factors. Using a participatory design approach, as to align robot capabilities to end-users' preferences, will enhance HRC and improve job quality. Abbreviations: HRC: human robot collaboration; OECD: organisation for economic co-operation and development.

Tibial anterior compartment compressibility in healthy subject, measured using compression sonography

INTRODUCTION

Compression sonography has been introduced for non-invasive measurement of compartment compressibility and possible diagnostic tool for acute or chronic compartment syndrome in studies using human cadavers and animal models. To date, standard values in healthy subjects are not yet defined. The aim was to define standard compartment compressibility values in healthy human subjects and to assess the reliability of this measurement method.

METHODS

In 60 healthy volunteers, using ultrasound, the diameter of the tibial anterior compartment was measured while applying no pressure, 10mbar and 80mbar of external pressure. A pressure manometer on the ultrasound head was used to monitor the externally applied pressure. Compartment compressibility ratio (R_0-80, respectively R_10-80) was calculated as following: The delta of the compartment diameter with high and low external pressure, divided through the diameter with low external pressure. In 10 volunteers, two examinators conducted each two measurements to assess the reliability.

RESULTS

Mean compartment compressibility ratio R_10-80 was 15.9% ±3.6 (range: 7.2 - 22.2). Mean compartment compressibility ratio R_0-80 was 18.2% ±5.0 (3.0 - 32.1). There was no significant correlation with lower leg circumference, height, weight, BMI, gender, hours of sport per week and type of sport (e.g. weightlifting/ cardio). For R_10-80, intraobserver ICC 2.1 was 0.89 for an experienced observer and 0.79 for a non-experienced observer. Interobserver ICC 2.1 was 0.78. For R_0-80, intraobserver ICC 2.1 was 0.71 for the experienced and 0.56 for the unexperienced observer. Interobserver ICC 2.1 was 0.59.

DISCUSSION

In healthy volunteers between 18 and 50 years of age, mean compartment compressibility ratio R_10-80 was 15.9% ±3.6, independent of demographic factors and sport activity. Application of 10mbar instead of 0mbar increased image quality. Subsequently, R_10-80 showed lower standard deviation and both higher intraobserver and interobserver reliability than R_0-80. Using R_10-80, this measurement method is reliable with very high intra- and interobserver correlation.

finDr: A web server for in silico D-peptide ligand identification

In the rapidly expanding field of peptide therapeutics, the short in vivo half-life of peptides represents a considerable limitation for drug action. D-peptides, consisting entirely of the dextrorotatory enantiomers of naturally occurring levorotatory amino acids (AAs), do not suffer from these shortcomings as they are intrinsically resistant to proteolytic degradation, resulting in a favourable pharmacokinetic profile. To experimentally identify D-peptide binders to interesting therapeutic targets, so-called mirror-image phage display is typically performed, whereby the target is synthesized in D-form and L-peptide binders are screened as in conventional phage display. This technique is extremely powerful, but it requires the synthesis of the target in D-form, which is challenging for large proteins. Here we present finDr, a novel web server for the computational identification and optimization of D-peptide ligands to any protein structure (https://findr.biologie.uni-freiburg.de/). finDr performs molecular docking to virtually screen a library of helical 12-mer peptides extracted from the RCSB Protein Data Bank (PDB) for their ability to bind to the target. In a separate, heuristic approach to search the chemical space of 12-mer peptides, finDr executes a customizable evolutionary algorithm (EA) for the de novo identification or optimization of D-peptide ligands. As a proof of principle, we demonstrate the validity of our approach to predict optimal binders to the pharmacologically relevant target phenol soluble modulin alpha 3 (PSMα3), a toxin of methicillin-resistant Staphylococcus aureus (MRSA). We validate the predictions using in vitro binding assays, supporting the success of this approach. Compared to conventional methods, finDr provides a low cost and easy-to-use alternative for the identification of D-peptide ligands against protein targets of choice without size limitation. We believe finDr will facilitate D-peptide discovery with implications in biotechnology and biomedicine.

The Effect of the Mobile Subtalar Joint on Calcaneal and Supramalleolar Osteotomies

BACKGROUND

The mobile subtalar joint (STJ) may compensate for supra- and inframalleolar deformities and counteract the effect of realigning calcaneal or distal tibial osteotomies. The purpose of this study was to evaluate the compensatory effect of the mobile STJ after supramalleolar osteotomy (SMOT) and calcaneus osteotomy (COT) and whether the extent of the compensation correlates with STJ shape and orientation.

METHODS

In 10 human lower leg cadavers without evidence of deformity or prior trauma 700 Newton load were applied as a simulated standing pose. The center of force (COF) migration, maximum pressure (Pmax), and the area loaded were measured with high-resolution sensors in the ankle before and after 10-mm varus/valgus sliding COT and 10-degree varus / valgus SMOT. A computed tomographic evaluation of subtalar anatomy was conducted to correlate posterior facet curvature, its varus/valgus orientation in the coronal plane, and the effect on COF, Pmax, and area loaded.

RESULTS

The COF migration was significant for both varus and valgus SMOTs (varus SMOT: 1.78 mm, P = .0029; valgus SMOT: 1.85 mm, P = .0018) but not for COT (varus COT: 0.45 mm, P = .85; valgus COT: 1.15 mm, P = .11). Pmax and area loaded changed but not significantly. The radius of the posterior STJ surface showed a moderate correlation (varus SMOT: r = 0.61, P = .063; valgus SMOT: r = 0.28, P = .43, varus COT: r = -0.61, P = .063; valgus COT: r = 0.13, P = .38) and the axis a weak inverse correlation (varus SMOT: r = -0.51, P = .013; valgus SMOT: r = 0.58, P = .079; varus COT: r = -0.51, P = .14; valgus COT: r = 0.38, P = .28) with the COF migration after the osteotomies.

CONCLUSION

The compensatory capacity of a mobile STJ is relatively small but appears to limit the effect of COT more than SMOT. The COT is less effective in influencing ankle joint pressure for realignment purposes than SMOT in mobile STJ and clinically more consistent in stiff STJ. Correlations are moderate to weak, whereas the curvature more than orientation of posterior facet inversely correlates with osteotomy's effects.

LEVEL OF EVIDENCE

Level IV, biomechanical cadaver study.

Weightbearing Radiography and MRI Findings in Ankle Fractures

Background. Static weightbearing radiography can be used to assess stability in ankle fractures by measuring lateral talar shift (medial clear space; MCS). However, the correlation of a stable ankle joint under weightbearing load and the structural integrity of the deltoid ligament has not been shown. In this study, we assessed deltoid ligament integrity on magnetic resonance imaging (MRI) and correlated that with weightbearing and gravity stress test radiography. Methods. Thirty-four patients with supination external rotation II-IV (SER) fractures underwent MRI, weightbearing radiography, and gravity stress test. On MRI, the deep anterior and posterior tibiotalar deltoid, tibionavicular and tibiocalcaneal ligaments, as well as the syndesmosis were assessed as intact, partial rupture, or complete rupture. The MCS was measured as the distance between the lateral border of the medial malleolus and the medial border of the talus at the level of the talar dome on the mortise view. Results. Twenty-three patients suffered a deep anterior tibiotalar ligament rupture (16 partial; 7 complete) and 2 a deep posterior tibiotalar ligament tear (1 partial; 1 complete). For MCS on weightbearing radiography, no statistically significant differences were identified between any of the individual groups. With gravity stress radiography, only a complete tear of the tibiocalcaneal ligament showed a significantly higher MCS than a partial tear or intact tibiocalcaneal ligament (P < .005). No other ligament disruption showed a significant difference between the complete rupture versus intact or partial tear. Conclusion. Weightbearing radiography does not show much variation in terms of MCS even with ligamentous disruption and fibula fracture. The talus often centers itself underneath the tibia with weightbearing radiography.Levels of Evidence: Level III: Retrospective cohort study.

Potentials and current shortcomings in the cooperation between German centers for rare diseases and primary care physicians: results from the project TRANSLATE-NAMSE

Background

The TRANSLATE-NAMSE project with the strengthening of the centers for rare diseases with their affiliation to the European Reference Networks was a major step towards the implementation of the German National Plan of Action for People with Rare Diseases establishing better care structures. As primary care physicians, general practitioners and pediatricians play a central role in the diagnosis of patients with rare disease, as it is usually them referring to specialists and rare disease centers. Therefore, the interface management between primary care physicians and the centers for rare diseases is of particular importance.

Methods

In a mixed-method-approach an anonymous postal survey of 1,500 randomly selected primary care physicians in Germany was conducted with focus on (1) knowledge about a center for rare diseases and how it works, (2) in case of cooperation, satisfaction with the services provided by centers, and (3) expectations and needs they have with regard to the centers. In addition, in-depth telephone interviews were conducted with physicians who had already referred patients to a center.

Results

In total, 248 physicians responded to the survey, and 15 primary care physicians were interviewed. We observed a wide lack of knowledge about the existence of (45.6% confirmed to know at least one center) about how to access rare disease centers (50.4% of those who know a center confirmed knowledge) and what the center specializes in. In case of cooperation the evaluation was mostly positive.

Conclusion

To improve medical care, the interplay between primary care physicians and rare disease centers needs to be strengthened. (1) To improve the communication, the objectives and functioning of the rare disease centers should become more visible. (2) Other projects dealing with the analysis and improvement of interface management between centers and primary care physicians, as described in the National Plan of Action for People with Rare Diseases, need to be implemented immediately. (3) If the project is evaluated positively, the structures of TRANSLATE-NAMSE should be introduced nationwide into the German health care system to ensure comprehensive, quality-assured care for people with rare diseases with special consideration of the key role of primary care physicians—also taking into account the financial expenditures of this new care model.

Management of gait impairments in people with Charcot-Marie-Tooth disease: A treatment algorithm

ABSTRACT

Gait impairments in people with Charcot-Marie-Tooth disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed and distance. Because these gait impairments and related complaints are disabling, clinical management aimed at improving gait is important. Management involves both conservative and surgical treatment options, each with limited scientific evidence. However, a treatment algorithm that describes both conservative and surgical treatment options is currently lacking. This study sets out a step-wise treatment algorithm, based on evidence, if available, and otherwise reflecting practice-based experience. The treatment algorithm will be of value in daily clinical practice, and will serve as a template for future research.

LAY ABSTRACT

Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it is a source of great disability. However, many clinicians find it difficult to treat these gait impairments in their daily clinical practice. This challenge is compounded by a lack of clear treatment protocols that take the whole spectrum of treatment options into account. As a result, there is wide variation in clinical practice. To address the widely felt need for a treatment algorithm, we present here a stepwise approach to the management of gait impairments in patients with Charcot-Marie-Tooth disease.

Simple and compact diode laser system stabilized to Doppler-broadened iodine lines at 633 nm

We present a compact iodine-stabilized laser system at 633 nm, based on a distributed-feedback laser diode. Within a footprint of 27×15cm², the system provides 5 mW of frequency-stabilized light from a single-mode fiber. Its performance was evaluated in comparison to Cs clocks representing primary frequency standards, realizing the SI unit Hz via an optical frequency comb. With the best suited absorption line, the laser reaches a fractional frequency instability below 10^-10 for averaging times above 10 s. The performance was investigated at several iodine lines, and a model was developed to describe the observed stability on the different lines.

Effect of Lateral Sliding Calcaneus Osteotomy on Tarsal Tunnel Pressure

Background:

Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus deformities. Shifting the calcaneal tuberosity laterally (lateralization) can lead to tarsal tunnel pressure increase and tibial nerve palsy. The purpose of this cadaveric biomechanical study was to investigate the correlation of lateralization and pressure increase underneath the flexor retinaculum.

Methods:

The pressure in the tarsal tunnel of 12 Thiel-fixated human cadaveric lower legs was measured in different foot positions and varying degrees of calcaneal lateralization.

Results:

The mean pressure increased from plantarflexion (PF) to neutral position (NP) and from NP to hindfoot dorsiflexion (DF), and with increasing amounts of lateralization of the calcaneal tuberosity. The mean baseline pressure in PF was 1.5, in NP 2.2, and in DF 6.5 mmHg and increased to 8.1 in PF, 18.4 in NP, and 33.1 mmHg with 12 mm of lateralization. The release of the flexor retinaculum significantly lowered the pressure.

Conclusion:

Increasing pressures were found in the tarsal tunnel with increasing lateralization of the tuberosity and with both dorsiflexion and plantarflexion of the ankle.

Clinical Relevance:

A pre-emptive release of the flexor retinaculum for a lateralization of the calcaneal tuberosity of more than 8 mm should be considered, especially if specific patient risk factors are present. No tibial nerve palsy should be expected with 4 mm of lateralization.

Return to Sport and Patient Satisfaction at 5-Year Follow-up After Nonoperative Treatment for Acute Achilles Tendon Rupture

BACKGROUND

There is controversy whether nonoperative or operative treatment for Achilles tendon rupture is superior. It is unknown if patients with acute Achilles tendon rupture return to previous sports activity. The purpose of this study was to assess 5-year return to sport and subjective satisfaction, minimum 1-year functional outcomes, and complications in patients following nonoperative treatment of Achilles tendon rupture with early weightbearing rehabilitation.

METHODS

An institutional review board-approved, retrospective observational study involving 89 patients was performed. Out of 114 consecutive patients, 89 (78%) responded to questionnaires for sports activity. Nonoperative treatment consisted of an equinus cast and rehabilitation boot that enabled early weightbearing. Sports activity at 1-year and 5-year follow-up was compared to the prerupture status. Based on the prerupture Tegner Activity Scale (TAS), patients were divided into low-level (<6) and high-level (≥6) activity groups. Clinical assessment at minimum 1-year follow-up was performed with the Thermann score. Mean clinical follow-up was 34 ± 23 months.

RESULTS

Overall, >70% of the patients returned to their previous sports activity level after a nonoperative early weightbearing treatment. Return-to-sport rate was significantly (P = .029) higher for patients in the low-level activity group (91%) compared to patients (67%) in the high-level activity group at 5-year follow-up. Subjective satisfaction with treatment was good in both groups (93% and 96%, respectively). The mean Thermann score did not differ between the 2 groups at 1-year follow-up. There were 11 reruptures, 5 deep venous thromboses, and 1 case of complex regional pain syndrome.

CONCLUSION

Nonoperative treatment for Achilles tendon rupture yielded good functional outcome and high patient satisfaction. For patients with a high preinjury activity level, return to previous sporting level (assessed by TAS) was possible in 67% of the patients compared to >90% of patients with low preinjury activity level.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Outcomes of Ultrasound-Guided Gastrocnemius Injection With Botulinum Toxin for Chronic Plantar Fasciitis

BACKGROUND

The objective of this study was to determine whether the injection of botulinum toxin A (BTA) in the medial head of the gastrocnemius muscle could yield improvements in function and disability in patients with chronic plantar fasciitis with follow-up 12 months after treatment.

METHODS

Thirty-two patients with chronic plantar fasciitis were included in the study and randomly allocated to the BTA and placebo groups. The visual analog scale (VAS) and American Orthopaedic Foot & Ankle Society (AOFAS) scores were used to evaluate pain levels pre- and postinjection as well as function of the foot, respectively. Patients were also asked to rate their treatment satisfaction 1 year after injection. The range of dorsiflexion was measured before and 12 months after the injection.

RESULTS

At the 12-month follow-up, the mean VAS decreased from 7.8 to 4 in the placebo group and from 8 to 0.33 in the BTA group. Furthermore, the mean AOFAS scores increased from 48.4 to 65.3 in the placebo group and from 45.5 to 90.6 in the BTA group. The postinjection scores in the BTA group were significantly higher than those in the placebo group (P < .001). Patient satisfaction in the BTA group was higher than that in the placebo group at the 12-month follow-up.

CONCLUSION

In patients with chronic plantar fasciitis, the use of BTA had a positive effect on improvement in pain and foot function 1 year after treatment.

LEVEL OF EVIDENCE

Level I, prospective randomized controlled trial.

Spinopelvic dissociation in patients suffering injuries from airborne sports

BACKGROUND

Spinopelvic dissociation which is also called U-type or referred to H-type sacral fractures with a transverse fracture line is an infrequent injury that results mainly from high-energy accidents. This results in an osseous dissociation of the upper central segment of the sacrum and the entire spine from the lower sacral segments. The purpose was to investigate the incidence of spinopelvic fracture in general among airborne injuries.

PATIENTS AND METHODS

Using our electronic patient records, we retrospectively investigated all sacral fractures related to airborne sports between 2010 and 2017. All injuries were classified according to the Roy-Camille, Denis, AOSpine and the Tile classification system.

RESULTS

During the period of interest, 44 patients (18.7%) were admitted with sacral fractures after accidents obtained from airborne sports, including 16 spinopelvic dissociations (36.4%). The majority of these injuries were obtained from paragliding (75.0%), followed by BASE jumping (21.4%) and parachuting (4%). The mean injury severity score (ISS) in the spinopelvic dissociation group was significantly higher compared with other sacral fracture group (38.1 vs. 20.0; p < 0.001). Six lambda-type, four T-type, four H-type and two U-type injuries were identified. In total, four patients (25%) were found to have neurological impairment. For treatment, 87.5% of patients underwent subsequent surgical stabilization.

CONCLUSION

Airborne sports have high potential for serious, life-threatening injuries with a high incidence of spinopelvic dissociation. In the literature, the prevalence of spinopelvic dissociation in sacral fractures is described to be between 3 and 5%. In our series, the prevalence is 36.4%. It is important to identify the potential injuries promptly for the further treatment. These slides can be retrieved under Electronic Supplementary Material.

Isolated Rupture of the Distal Plantaris Muscle

In the present case, the plantaris tendon was ruptured in isolation and at the distal part of the tendon. An injury of the Achilles tendon, gastrocnemius muscle, or soleus muscle was not detected. To the best of our knowledge, a similar case has not yet been reported. Our case basically demonstrates that a rupture of the musculus plantaris does not have to occur at the myotendiouns junction or the muscle belly itself. The initial nonoperative treatment with physiotherapy, antiinflammatory medicine, and an early return to sports, even for this more distal plantaris tendon rupture, led to a good result.

Cranio-caudal and medio-lateral navicular translation are representative surrogate measures of foot function in asymptomatic adults during walking

Introduction

The translation of the navicular bone is thought to be a representative surrogate measure to assess foot pronation and hence foot function; however, it is not known how it is related to multi-segment foot kinematics.

Methods

Cranio-caudal (NCC) and medio-lateral (NML) navicular translation and multi-segment foot kinematics from the Oxford Foot Model (OFM) were simultaneously assessed during the stance phase of walking in 20 healthy adults. Relationships to forefoot to hindfoot (FFtoHF), hindfoot to tibia (HFtoTBA) and global hindfoot (HFL) motion were explored by cross-correlations at zero phase shift.

Results

FFtoHF sagittal, transversal and frontal plane angles showed median cross correlations of -0.95, 0.82 and 0.53 with NCC and of 0.78, -0.81 and -0.90 with NML. HFtoTBA transversal and frontal plane angles had correlations of 0.15 and 0.74 with NCC and of -0.38 and -0.83 with NML. The HFL frontal plane angle showed correlations of 0.41 and -0.44 with NCC and NML, respectively.

Discussion

The strongest relationships were found between FFtoHF sagittal plane angles and NCC and between FFtoHF frontal plane angles and NML. However, cranio-caudal and medio-lateral navicular translation seem to be reasonable surrogates for the triplanar motion between the fore- and hindfoot. The medial longitudinal arch dropped and bulged medially, while the forefoot dorsiflexed, abducted and everted with respect to the hindfoot and vice-versa. The lower cross-correlation coefficients between the rear foot parameters and NCC/NML indicated no distinct relationships between rearfoot frontal plane and midfoot kinematics. The validity of rearfoot parameters, like Achilles tendon or Calcaneal angle, to assess midfoot function must be therefore questioned. The study could also not confirm a systematic relationship between midfoot kinematics and the internal/external rotation between the hindfoot and the tibia. The measurement of navicular translation is suggested as an alternative to more complex multi-segment foot models to assess foot function.

Malalignment and Lateral Ankle Instability: Causes of Failure from the Varus Tibia to the Cavovarus Foot

A lower leg or hindfoot varus malalignment is a frequently encountered but underestimated cause of chronic ankle instability and ankle arthritis in the long term. When evaluating patients with ankle instability, a high index of clinical suspicion for tibia and hindfoot malalignment and subsequent biomechanics should be maintained. Management of lateral ankle instability in the presence of varus malalignment must comprise a generous indication for accurate hindfoot realignment. In young and active patients, realignment should be combined with formal lateral ligamentous repair.

LagLoc-a new surgical technique for locking plate systems

Treatment of oblique and spiral fractures remains challenging. The aim of this study was to introduce and investigate the new LagLoc technique for locked plating with generation of interfragmentary compression, combining the advantages of lag screw and locking-head-screw techniques. Oblique fracture was simulated in artificial diaphyseal bones, assigned to three groups for plating with a seven-hole locking compression plate. Group I was plated with three locking screws in holes one, four, and seven. The central screw crossed the fracture line. In group II the central hole was occupied with a lag screw perpendicular to fracture line, whereas holes one and seven were occupied with locking screws. Group III was instrumented applying the LagLoc technique as follows. Hole four was predrilled perpendicularly to the plate, followed by overdrilling of the near cortex and insertion of a locking screw-crossing the fracture line-whose head was covered by a holding sleeve to prevent temporarily the locking in the plate hole and generate interfragmentary compression. Subsequently, the screw head was released and locked in the plate hole. Holes one and seven were occupied with locking screws. Interfragmentary compression in the fracture gap was measured using pressure sensors. All screws in the three groups were tightened with 4 Nm torque. Interfragmentary compression in group I (167 ± 25 N) was significantly lower in comparison to groups II (431 ± 21 N) and III (379 ± 59 N), p ≤ 0.005. The difference in compression between groups II and III remained not significant (p = 0.999). The new LagLoc technique offers an alternative tool to generate interfragmentary compression with the application of locking plates by combining the biomechanical advantages of lag screw and locking screw fixations. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2886-2891, 2018.

Is Optical Coherence Tomography a Potential Tool to Evaluate Marginal Adaptation of Class III/IV Composite Restorations In Vivo?

OBJECTIVE

Margin analysis of Class III and IV composite restorations in vitro and in vivo occurred by scanning electron microscopy (SEM) and optical coherence tomography (OCT). The results were compared and related to clinical evaluation.

METHODS AND MATERIALS

Eight Class III composite restorations were imaged in vitro using OCT and SEM. The margins were analyzed quantitatively. OCT signals were verified by assignment to the criteria perfect margin, gap, and positive/negative ledge. In vivo quantitative margin analysis of Class III/IV composite restorations made of the micro-hybrid composite Venus combined with the self-etch adhesive iBond Gluma inside (1-SE) or etch-and-rinse adhesive Gluma Comfort Bond (2-ER) (all Heraeus Kulzer) was carried out using OCT and SEM after 90 months of clinical function. The results were compared with clinical evaluation (US Public Health Service criteria; marginal integrity, marginal discoloration).

RESULTS

In vitro, the correlation between OCT and SEM was high for all four margin criteria (Kendall tau b [τ_b] correlation: 0.64-0.92, p_i≤0.026), with no significant differences between OCT and SEM (p_i≥0.63). In vivo, a moderate correlation was observed (τ_b: 0.38-0.45, p_i<0.016). Clinically, the cumulative failure rate in the criterion marginal integrity was higher for the 1-SE group (baseline 90 M, p=0.011). Similarly, OCT and SEM detected higher percentages of the criterion gap in the 1-SE group (p: 0.027/0.002), in contrast to perfect margin. Both, gap and perfect margin ranged widely between 0.0% and 88.7% (OCT) and between 0.0% and 89.0% (SEM).

CONCLUSION

Despite the positive selection bias after 90 months with only a few patients left, quantitative margin analysis allows for differentiation between the two adhesives at this specific date. OCT in particular offers the possibility to evaluate marginal integrity directly in vivo.

A minimal markerset for three-dimensional foot function assessment: measuring navicular drop and drift under dynamic conditions

Background

The validity of predicting foot pronation occurring mainly at the midfoot by surrogate measures from the rearfoot, like eversion excursion, is limited. The dynamic navicular mobility in terms of vertical navicular drop (dNDrop) and medial navicular drift (dNDrift) may be regarded as meaningful clinical indicators to represent overall foot function. This study aimed to develop a minimal approach to measure the two parameters and to examine their intra- and interday reliability during walking.

Methods

The minimal markerset uses markers at the lateral and medial caput of the 1^st and 5^th metatarsals, respectively, at the dorsal calcaneus and at the tuberosity of the navicular bone. Dynamic navicular drop and drift were assessed with three-dimensional motion capture in 21 healthy individuals using a single-examiner test-retest study design.

Results

Intra- and interday repeatability were 1.1 mm (ICC₂₁ 0.97) and 2.3 mm (ICC₂₁ 0.87) for dynamic navicular drop and 1.5 mm (ICC₂₁ 0.96) and 5.3 mm (ICC₂₁ 0.46) for dynamic navicular drift. The contribution of instrumental errors was estimated to 0.25 mm for dynamic navicular drop and 0.86 mm for dynamic navicular drift.

Conclusions

Interday reliability was generally worse than intraday reliability primary due to day-to-day variations in movement patterns and the contribution of instrumental errors was below 23% for dynamic navicular drop but reached 57% for dynamic navicular drift. The minimal markerset allows to simply transfer the known concepts of navicular drop and drift from quasi-static clinical test conditions to functional tasks, which is recommended to more closely relate assessments to the functional behavior of the foot.

Electronic supplementary material

The online version of this article (10.1186/s13047-018-0257-2) contains supplementary material, which is available to authorized users.

Effect of Preoperative Deformity on Arthroscopic and Open Ankle Fusion Outcomes

INTRODUCTION

Coronal deformity is considered a relative contraindication for arthroscopic ankle fusion. This study assessed whether preoperative coronal ankle joint deformity influenced the outcome of arthroscopic ankle fusion.

METHODS

Ninety-seven patients had 62 arthroscopic and 35 open ankle fusions between 2005 and 2012. Clinical outcomes were prospectively recorded with use of the Ankle Osteoarthritis Scale (AOS) and Ankle Arthritis Scale (AAS) preoperatively and at 6, 12, and 24 months and final follow-up. Radiological alignment was measured using the tibiotalar angle, the tibial plafond angle, the lateral talar station, and the lateral tibiotalar angle. Both groups had the same demographics.

RESULTS

Preoperative deformity was the same regarding sagittal alignment and overall coronal alignment, but the arthroscopic group had less tibial deformity (tibial plafond angle range 0-19 degrees vs 0-43 degrees). At final follow-up, the mean AOS was 34.2 for arthroscopic (95% confidence interval [CI], 23.3-45.2) vs 33.9 for open (95% CI, 17.8-49.9). The AAS at final follow-up was 26.0 for arthroscopic (95% CI, 21.0-31.0) vs 27.5 for open (95% CI, 19.7-35.2). Both groups had the same tibiotalar angle, lateral talar station, and lateral tibiotalar angle at follow-up. Regression analyses revealed no influence of type of surgery, preoperative deformity, postoperative radiological alignment, age, sex, body mass index, smoking status, etiology of the arthritis, and need for bone grafting on outcome scores (all P > .05).

CONCLUSION

Arthroscopic and open ankle fusion yielded equivalent results for both patient-reported outcome measure and radiographic alignment in patients with coronal and sagittal joint deformity. Patients with higher tibial plafond angles more often underwent open fusion.

LEVEL OF EVIDENCE

III, comparative series.

Application of micro-FTIR mapping and SEM to study compositional heterogeneity of siltstones: Example from the Late Devonian-Early Mississippian Middle Bakken Member

This paper explores the applicability of micro-FTIR mapping to study heterogeneity of organic matter-lean siltstones. Closely spaced samples of Late Devonian dolomitic siltstones of the Middle Bakken Member were analysed with micro-FTIR, powder X-ray diffraction, and scanning electron microscopy (SEM) to explore the distribution and chemical properties of organic matter (OM), muscovite/feldspar/clay group, carbonates, and quartz, and their influence on porosity and permeability of these rocks. Our results show that quartz is the dominant component of the samples, and the main mineralogical differences between the samples are reflected in the abundance of carbonate minerals. Organic matter content is usually far below 1 wt. % and dominantly represented by terrestrially derived vitrinite and inertinite. Micro-FTIR mapping demonstrates that the more spatially connected quartz and muscovite/feldspar/clays become, the larger permeability in the rock develops, and these correlations are especially strong for planes parallel to bedding. In contrast, carbonate connectivity shows a strong negative correlation with permeability. No correlations between connectivity of components and porosity have been detected. These observations suggest that micro-FTIR not only can document compositional heterogeneity of siltstones, but also has potential to help understanding their permeability systems.

Weightbearing vs Gravity Stress Radiographs for Stability Evaluation of Supination-External Rotation Fractures of the Ankle

BACKGROUND

Isolated lateral malleolar fractures may result from a supination-external rotation (SER) injury of the ankle. Stable fractures maintain tibiotalar congruence due to competent medial restraints and can be treated nonoperatively with excellent functional results and long-term prognosis. Stability might be assessed with either stress radiographs or weightbearing radiographs.

METHODS

A consecutive series of patients with closed SER fractures (presumed AO 44-B1) were prospectively enrolled from 2008 to 2015. Patients with clearly unstable fractures (medial clear space more than 7 mm) on the initial nonweightbearing radiograph were excluded and operated on. All other patients were examined with a gravity stress and a weightbearing anteroposterior radiograph. Borderline instability of the fracture was assumed when the medial clear space was 4 to 7 mm. Those were treated nonoperatively.

RESULTS

Of 104 patients with isolated lateral malleolar fractures of the SER type, 14 patients were treated operatively because of clear instability (displacement) on the initial radiographs. Of the nonoperative patients, 44 patients demonstrated borderline instability on the gravity stress but stability on the weightbearing radiograph ("gravity borderline"); the remaining 46 were stable in both tests ("gravity stable"). At an average follow-up of 23 months, no significant differences were seen in the American Orthopaedic Foot & Ankle Society hindfoot score (92 points gravity-borderline group vs 93 points gravity-unstable group), the Foot Functional Index score (11 vs 10 points), the Short Form 36 (SF-36) physical component (86 vs 85 points), and SF-36 mental component (84 vs 81 points). Radiographically, all fractures had healed with anatomic congruity of the ankle.

CONCLUSION

Weightbearing radiographs provided a reliable basis to decide about stability and nonoperative treatment in isolated lateral malleolar fractures of the SER type with excellent clinical and radiographic outcome at short-term follow-up. Gravity stress radiographs appear to overrate the need for operative treatment.

LEVEL OF EVIDENCE

Level III, prospective comparative study.

Ankle joint pressure changes in high tibial and distal femoral osteotomies: a cadaver study

AIMS

To assess the effect of high tibial and distal femoral osteotomies (HTO and DFO) on the pressure characteristics of the ankle joint.

MATERIALS AND METHODS

Varus and valgus malalignment of the knee was simulated in human cadaver full-length legs. Testing included four measurements: baseline malalignment, 5° and 10° re-aligning osteotomy, and control baseline malalignment. For HTO, testing was rerun with the subtalar joint fixed. In order to represent half body weight, a 300 N force was applied onto the femoral head. Intra-articular sensors captured ankle pressure.

RESULTS

In the absence of restriction of subtalar movement, insignificant migration of the centre of force and changes of maximal pressure were seen at the ankle joint. With restricted subtalar motion, more significant lateralisation of the centre of force were seen with the subtalar joint in varus than in valgus position. Changes in maximum pressure were again not significant.

CONCLUSION

The re-alignment of coronal plane knee deformities by HTO and DFO altered ankle pressure characteristics. When the subtalar joint was fixed in the varus position, migration of centre of force after HTO was more significant than when the subtalar joint was fixed in valgus. Cite this article: Bone Joint J 2017;99-B:59-65.

Clinical Outcomes of Nonunions of Hindfoot and Ankle Fusions

BACKGROUND

While nonunion after foot and ankle fusion surgery has been associated with poor outcomes, we are not aware of any longitudinal study on this subject. Thus, we prospectively evaluated the impact of nonunion on clinical outcomes of foot and ankle fusions and identified potential risk factors for nonunion after these procedures.

METHODS

Using data from a randomized clinical trial on recombinant human platelet-derived growth factor-BB (rhPDGF-BB; Augment Bone Graft, BioMimetic Therapeutics), union was defined either by assessment of computed tomography (CT) scans at 24 weeks by a reviewer blinded to the type of treatment or by the surgeon's composite assessment of clinical and radiographic findings at 52 weeks and CT findings at 24 or 36 weeks. The nonunion and union groups (defined with each assessment) were then compared in terms of clinical outcome scores on the American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS-AHS), Foot Function Index (FFI), and Short Form-12 (SF-12) as well as age, sex, body mass index (BMI), smoking status, diabetes status, work status, and arthrodesis site.

RESULTS

Blinded CT assessment identified nonunion in 67 (18%) of 370 patients, and surgeon assessment found nonunion in 21 (5%) of 389 patients. Postoperatively, the nonunion group scored worse than the union group, regardless of the method used to define the nonunion, on the AOFAS-AHS and FFI, with mean differences of 10 and 12 points, respectively, when nonunion was determined by blinded CT assessment and 19 and 20 points when it was assessed by the surgeon. The nonunion group also had worse SF-12 Physical Component Summary scores. Differences between the union and nonunion groups were clinically meaningful for all outcome measures, regardless of the nonunion assessment method. The concept of an asymptomatic nonunion (i.e., imaging indicating nonunion but the patient doing well) was not supported. Patients with nonunion were more likely to be overweight, smokers, and not working.

CONCLUSIONS

This prospective longitudinal study demonstrated poorer functional outcomes in patients with a nonunion after foot and ankle fusion, regardless of whether the diagnosis of nonunion was based on CT only or on combined clinical, radiographic, and CT assessment.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Quality of Early Union After First Metatarsophalangeal Joint Arthrodesis

The aim of the present retrospective cohort study was to assess the quality of union and the clinical outcomes in patients who had undergone first metatarsophalangeal joint (MTPJ) fusion using a dorsal plate and plantar lag screw. From March 2011 to December 2012, the clinical and radiographic data of 39 patients (41 feet) who had undergone first MTPJ fusion using a compressive locking plate were retrospectively reviewed. All patients had undergone postoperative computed tomography at 6 weeks postoperatively to assess union. The average metatarsophalangeal angles improved from 23° ± 16° preoperatively to 14° ± 5° postoperatively. The dorsiflexion of the hallux at the preoperative assessment averaged 17° ± 11° and 23° ± 5° postoperatively. At 6 weeks postoperatively, the computed tomography scans demonstrated 3 complete fusions (7.3 %) and 38 partial unions (92.7%). Also at 6 weeks, the mean ± standard deviation joint bridging was 54% ± 14.6%. The forefoot American Orthopaedic Foot and Ankle Society scale score had improved significantly from 50 ± 13 preoperatively to 80 ± 7 at >1 year of follow-up (p = .001). Hardware removal was performed in 8 cases because of pain in 7 and infection in 1. Revision arthrodesis was required in 2 cases because of nonunion. At 6 weeks postoperatively, partial bony joint bridging could be observed in most cases after arthrodesis of the first MTPJ with the dorsal fusion plate.

Office chairs are often not adjusted by end-users

To find out how many office workers adjust their chairs, 350 office workers in Spain and the Netherlands are observed and questioned on whether they adjust their chairs. It appears that 24% of 236 Spanish office workers and 61% of 100 Dutch subjects never adjust their chair. If the chair is adjusted, it concerns mostly the seat height. Except for the seat height, other adjustment possibilities are not used by the majority of the study population. Reasons for not adapting could be awareness, complexity of the control system and expected effects.

Dentin Protection of Different Desensitizing Varnishes During Stress Simulation: An In Vitro Study

OBJECTIVE

The aim of this study was to investigate dentin protection of different desensitizing varnishes (light- and self-curing) during acid action/abrasion stress and thermocyclic loading in vitro.

METHODS

Dentin discs of 2 mm thickness were cut from 120 human molars, embedded, and polished. Specimens were randomized into five groups (n=24): A, negative control; B, Gluma Desensitizer; C, Cervitec plus (self-curing); D, Seal&Protect; and E, Admira Protect (light-curing). In groups B-E, varnish was applied on two-thirds of the dentin surface, and one-third acted as internal control. Stress cycle (2 cycles/day) for specimens were as follows: 1, acid action (pH: 2.9: five minutes); 2, remineralization (synthetic saliva: 60 minutes); 3, brushing (100 strokes); 4, thermocycling (five cycles); and 5, remineralization (synthetic saliva: six hours) for each group (n=12) for 30 (15 days) or 60 times (30 days). Specimens were analyzed using an incident light microscope. Substance loss was measured in micrometers. Statistical analysis was performed with the multiple contrast test (p<0.05).

RESULTS

Groups B and C had a significantly lower dentin loss than A (p<0.01). After 30 days, group A showed the highest dentin loss (p<0.01), whereas the other groups lacked a significant difference regarding their substance loss (dentin and/or varnish; p>0.05). Varnish layer loss was shown for groups D and E with a remaining protective layer; groups A-C showed dentin removal.

CONCLUSION

All four varnishes are protective compared with an untreated control. Light-curing varnishes might provide higher dentin protection than self-curing materials.

Morphology of the Hindfoot in Pes Cavus

Category:

Hindfoot

Introduction/Purpose:

The characteristic cavovarus deformity includes an adducted forefoot, an elevated longitudinal arch, and a hindfoot varus. However, little is known whether the deformity simply reflects pathologic joint orientations caused by muscular imbalance or whether it is rather provoked by alterations of the bony morphology. The purpose of the study was to further evaluate the source of the neurogenic and idiopathic cavovarus deformity by weightbearing 3D CT.

Methods:

Weightbearing CT scans of 12 patients with neurogenic and 17 patients with idiopathic cavovarus deformity were compared to neutrally aligned feet of 19 volunteers. AMIRA® software was employed to segment individual bones and to generate a 3D model. The 3D joint surface vector (JSV) with its 3 components in the transverse, coronal, and sagittal plane was computed for each joint surface of the talus, calcaneus, navicular and distal tibia. The positions of the ankle, subtalar and talonavicular joints were compared among the groups using the JSVs of the corresponding joint surfaces. The relative orientations of the joint surfaces on each individual bone were compared using the JSVs of head, trochlea and posterior facet for the talus; posterior facet and anterior process for the calcaneus; and anterior and posterior surfaces for the navicular. ANOVA tests were used for statistical analyses. Only statistically significant results (p < 0.05) are reported in this abstract.

Results:

Regarding the joint orientations, the talonavicular joint revealed 9° more adduction in idiopathic cavovarus feet than in control feet. In the neurogenic and idiopathic cavovarus groups the talar head exposed 34° and 20°, respectively, more adduction relative to the trochlea and 19° and 25°, respectively, more adduction relative to the subtalar joint than in the control group. Neurogenic cavovarus feet had 11° and 16°, respectively, more talar head internal rotation in the coronal plane relative to the subtalar joint than idiopathic cavovarus and control feet. In the idiopathic cavovarus group the anterior calcaneal process showed 9° more adduction relative to the posterior calcaneal facet and the anterior navicular surface had 8° more plantar flexion relative to the posterior navicular surface than in the control group.

Conclusion:

Alterations of bone morphology were more pronounced in the neurogenic group and mainly related to the talar head, whereas the idiopathic group also exposed changes of calcaneal and navicular bone morphology and talonavicular joint orientation. This indicates that the idiopathic cavovarus deformity is more induced by pathologic joint orientations due to muscular imbalance (or forefoot-driven) than the neurogenic deformity. Thus, neurogenic more so than idiopathic cavovarus deformities entail bone morphology changes of the hindfoot (hindfoot-driven), too. Therefore, to fully address the deformity corrective osteotomies, i.e. talar head realignment for neurogenic cavovarus feet, should be taken into consideration.

Ankle Joint Pressure Changes in High Tibial and Distal Femoral Osteotomies

Category:

Ankle Arthritis

Introduction/Purpose:

There is evidence from clinical studies and case reports that realignment of knee deformities for accompanying arthritis by high tibial- (HTO) and distal femoral osteotomies (DFO) inevitably changes the hindfoot alignment and ankle pressure characteristics.

Methods:

Varus and valgus malalignment of the knee was simulated in 12 fresh-frozen human cadaver full-length legs by removal of 5° bony wedges below and above the knee, respectively. Three hundred Newton, representing half body weight were applied onto the femoral head for static axial compression. Intra-articular high-resolution ankle sensors captured pressure. Testing included four measurements: baseline malalignment (1), 5° (2) and 10° realigning osteotomy (3), and control baseline malalignment (4). For the more common HTO, testing was rerun with the subtalar joint fixed in varus and valgus position.

Results:

Compared to the baseline measurement the opening HTO of 5° led to a mean center of force (COF) medialization of 0.1 mm and a HTO of 10° to a mean lateralization of 0.5 mm. The closing DFO of 5° and 10° both led to a COF mean medialization of 0.3 mm. No COF migration or change of Pmax was significant. With the subtalar joint fixed in varus position significant lateralizations of the COF was seen for the 5° HTO (2.5 mm) and the 10° HTO (2.9 mm). With the subtalar joint fixed in valgus position the 5° HTO led to a COF lateralization of 1.1 mm (significant) and the 10° to a COF lateralization of 0.9 mm (not significant). Pmax changes were not significant.

Conclusion:

In this biomechanical study, realignment of coronal plane deformities around the knee by HTO and DFO altered ankle pressure characteristics. The COF migration after HTO was significant, when the subtalar joint was fixed. Clinical relevance When indicating a HTO for medial rather than DFO for lateral knee arthritis or deformities, the impact on ankle pressure characteristics should be considered, particularly when compensatory capacity of the subtalar joint is restricted.

Arthroscopic Ankle Fusion

Category:

Ankle Arthritis

Introduction/Purpose:

Arthroscopic ankle arthrodesis (AAA) has been shown to result in reduced postoperative stay and better short-term outcome than open ankle arthrodesis. Coronal ankle joint deformity often is considered a contraindication for AAA. The aim of this study was to examine whether a preoperative coronal deformity influenced the midterm outcome after AAA for end-stage ankle arthritis.

Methods:

The Canadian Orthopaedic Foot and Ankle Society (COFAS) database prospectively collects data about the outcome of patients after surgical treatment of end-stage ankle arthritis. The database yielded 98 patients who had isolated ankle arthrodesis at the University of British Columbia between 2005 and 2013. The cohort consisted of 66 men and 32 women who had 62 arthroscopic and 38 open arthrodesis. The preoperative coronal deformity was measured using the tibiotalar angle (between a line perpendicular to the anatomical axis of the tibia and the proximal talar surface) and the tibial plafond angle (between a line perpendicular to the tibial axis and the distal tibial surface) on weight-bearing x-rays. Primary outcome measure was the COFAS Ankle Arthritis Scale (COFAS-AAS) at final follow-up. Secondary outcome measures were the reduction of the COFAS-AAS (ΔCOFAS-AAS) and the medial tibiotalar surface angle (between the anatomical axis and the proximal talar surface) at final follow-up.

Results:

The tibiotalar angle was lower in the arthroscopic than in the open group (8.2°±7.0 vs. 12.3°±8.2, p=.014) with similar range in both groups (0-25° vs. 0-27°). However, the tibial plafond angle (3.6°±11.4 vs. 11.4°±12.3, p< .005) and its range (0-19° vs. 0-43°) were markedly different. (Figure) The arthroscopic group scored slightly better regarding COFAS-AAS (26.0±19.8 vs. 28.8±23.6, p=.529) and ΔCOFAS-AAS (- 28.1±19.6 vs. -25.9±20.8, p= .603). Concerning patients with tibial plafond angles ≤19°, again the arthroscopic group had slightly better COFAS-AAS (26.0±19.8 vs. 28.9±12.4, p=.588) and ΔCOFAS-AAS (-28.1°±19.6 vs. -26.0°±18.5, p=.627). Regression analyses revealed no effect of tibiotalar or tibial plafond angle onto COFAS-AAS (p=.267 and p= .965) and ΔCOFAS- AAS (p=.741 and p=.392). Radiographic outcome was similar in both groups (medial tibiotalar angle 89.3°±2.2 vs. 88.1°±4.4, p=.135).

Conclusion:

Both, arthroscopic and open arthrodesis were associated with significant improvements in the COFAS-AAS and acceptable radiographic alignment. Former studies used the tibiotalar angle to describe preoperative coronal ankle joint deformity. In the presented study the range of the preoperative tibiotalar angle was similar in both groups, whereas all patients with tibial plafond angles ≥20° had an open arthrodesis. Therefore, the tibial plafond angle seems to better assist when deciding between arthroscopic or open arthrodesis in patients with a coronal ankle joint deformity. Within these limits preoperative coronal deformity had no influence on the outcome of arthroscopic ankle arthrodesis.

Current Swiss Techniques in Management of Lisfranc Injuries of the Foot

The outcome after Lisfranc injuries correlates with anatomic and stable reduction. The best surgical treatment, particularly for the ligamentous Lisfranc injuries, remains controversial. Recent publications suggest that the ligamentous injuries may benefit from primary partial Lisfranc arthrodesis. Most surgeons agree that an appropriate reduction is better and easier achieved by open reduction and stable temporary screw or dorsal plate fixation or by open primary partial arthrodesis than by closed reduction or Kirschner wire fixation. Despite correct surgical technique and postoperative management, symptom-free recovery is uncommon. This article outlines current techniques in the management of Lisfranc injuries and resultant postoperative outcomes in a level I trauma center.

Operative Treatment of Acute Fractures of the Tarsal Navicular Body: Midterm Results With a New Classification

BACKGROUND

Treatment of displaced tarsal navicular body fractures usually consists of open reduction and internal fixation. However, there is little literature reporting results of this treatment and correlation to fracture severity.

METHODS

We report the results of 24 patients treated in our institution over a 12-year period. Primary outcome measurements were Visual-Analogue-Scale Foot and Ankle score (VAS-FA), AOFAS midfoot score, and talonavicular osteoarthritis at final follow-up. According to a new classification system reflecting talonavicular joint damage, 2-part fractures were classified as type I, multifragmentary fractures as type II, and fractures with talonavicular joint dislocation and/or concomitant talar head fractures as type III. Spearman's coefficients tested this classification's correlation with the primary outcome measurements. Mean patient age was 33 (range 16-61) years and mean follow-up duration 73 (range 24-159) months.

RESULTS

Average VAS-FA score was 74.7 (standard deviation [SD] 16.9), and average AOFAS midfoot score was 83.8 (SD = 12.8). Final radiographs showed no talonavicular arthritis in 5 patients, grade 1 in 7, grade 2 in 3, grade 3 in 6, and grade 4 in 1 patient. Two patients had secondary or spontaneous talonavicular fusion. Spearman coefficients showed strong correlation of the classification system with VAS-FA score (r = -0.663, P < .005) and talonavicular arthritis (r = 0.600, P = .003), and moderate correlation with AOFAS score (r = -.509, P = .011).

CONCLUSION

At midterm follow-up, open reduction and internal fixation of navicular body fractures led to good clinical outcome but was closely related to fracture severity. A new classification based on the degree of talonavicular joint damage showed close correlation to clinical and radiologic outcome.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Supramalleolar Osteotomies for Posttraumatic Malalignment of the Distal Tibia

Supramalleolar osteotomies of the tibia (SMOT) for posttraumatic distal tibial malalignment has shown to reduce pain, improve function and radiographic signs of osteoarthritis, and delay ankle arthrodesis or total joint replacement. The procedure also protects the articular cartilage from further degenerative processes by shifting and redistributing loads in the ankle joint. It is technically demanding and requires extensive preoperative planning. The type of osteotomy (opening vs closing wedge) does not influence the final outcome. However, based on the limited evidence, a grade I treatment recommendation has been given for supramalleolar osteotomies of the tibia to treat mild to moderate ankle arthritis in the presence of distal tibial malalignment.