Simulation in shoulder arthroplasty education using three-dimensional planning software: the role of guidelines and predicted range of motion.

AIM: To demonstrate how reverse shoulder arthroplasty (RSA) planning software could be used to improve how the trainees position glenoid and humeral implants and obtain optimal simulated range of motion (ROM). METHODS: We selected four groups of five various level participants: medical student (MS), junior resident (JR), senior resident (SR), and shoulder expert (SE). Thereafter, the 20 participants planned five cases of arthritic shoulders for a RSA on a validated planning software following three phases: (1) no guidelines and no ROM feedback, (2) guidelines but no ROM feedback, and (3) guidelines and ROM feedback. We evaluated the final simulated impingement-free ROM, the choice of the implant (baseplate size, graft, glenosphere), and the glenoid implant positioning. RESULTS: MS planning were significantly improved by the ROM feedback only. JR took the best advantage of both guidelines and ROM in final results. SR planning were less performant than SE into phase 1 regarding flexion, external rotation, and adduction (respectively - 10°, p = 0.03; - 11°, p = 0.003; and - 3°, p = 0,03), but reached similar results into phase 3 (respectively - 2°, p = 0.329; - 4°, p = 0.44; - 2°, p = 0.319). For MS, JR, and SR, we observed a systematic improvement in the agreement over the study course. The glenoid diameter remained highly variable even for SE. Comparing glenoid implant position to SE, the distance error decreased with advancing phases. CONCLUSION: Planning software can be used as a simulation training tool to improve implant positioning in shoulder arthroplasty procedures.

Ultrasound-Guided Proximal and Distal Suprascapular Nerve Blocks: A Comparative Cadaveric Study.

OBJECTIVES: The primary aim of our study was to evaluate and compare the accuracy of ultrasound (US)-guided distal suprascapular nerve (dSSN) and proximal SSN (pSSN) blocks. Secondary aims were to compare the phrenic nerve involvement between groups and to describe the anatomical features of the sensory branches of the dSSN. METHODS: pSSN and dSSN blocks were performed in 14 cadavers (28 shoulders). Ten mL of 0.2% ropivacaine colored with methylene blue was injected under US guidance. Accuracy was determined using SSN staining and the distance between predefined anatomical landmarks and the targeted SSN. The phrenic nerve (PN) was judged to be colored or not. The distribution of the sensory branches that originate from the 14 dSSNs is described. Quantitative data are expressed as median (range). RESULTS: The pSSN was dyed more frequently than the dSSN (13 vs 11, P = 0.59). The targeted SSN was close to the suprascapular notch (1.3 [0-5.2] cm) and the origin of the SSN (1.4 [0.2-4.5] cm) for dSSN and pSSN blocks, respectively (P = 0.62). For dSSN blocks, the most frequent injection site was the supraspinous fossa. Three PNs were marked in pSSN blocks, compared with none in dSSN blocks (P = 0.22). Three sensory branches were identified for all 14 dSSNs: the medial subacromial branch, the lateral subacromial branch, and the posterior glenohumeral branch. CONCLUSIONS: US-guided pSSN and dSSN blocks can be realized with accuracy. A distal approach to the SSN could be an alternative to interscalene brachial plexus block for the management of postoperative pain after shoulder surgery in high-respiratory risk patients.

The precision of patient-specific instrumentation guides for the positioning of the glenoid component in total reverse shoulder arthroplasty: an in vivo scanographic study.

OBJECTIVE: Optimal position and fixation of the baseplate is essential for the longevity of the reverse shoulder arthroplasty (RSA) and the patient-specific instrumentation (PSI) can help the surgeon to achieve that purpose. The aim of this study was to assess the reliability of the PSI guides for the positioning of the baseplate and the fixation's screws. METHOD: Prospective study involving 35 patients operated for RSA. The PSI guides were planned and used by the senior surgeon in all cases. We compared the planned orientation (frontal and axial) of the baseplate and the screws with the post-operative CT scan. RESULTS: The mean difference between the planned measures and the post-op measures was inferior to 2.5°. The screw's length corresponded with the pre-op plan in 70% of the cases. CONCLUSION: The use of a PSI guide to position the glenoid implant in total reverse shoulder arthroplasty is reliable, reduces the risk of positioning errors and improves the quality of fixation with the screws.

Ultrasound-Guided Versus Landmark-Based Approach to the Distal Suprascapular Nerve Block: A Comparative Cadaveric Study.

PURPOSE: To compare the accuracy of distal suprascapular nerve (dSSN) blockade performed with the use of ultrasound-guided regional anesthesia (USRA) versus with a landmark-based approach (LBA). A secondary aim was to describe the anatomic features of the sensory branches of the dSSN. METHODS: USRA and LBA were performed in 15 shoulders each from 15 cadavers (total of 30 shoulders). Then, 10 mL of methylene blue‒infused ropivacaine 0.75% was injected into the dSSN. Simultaneously, 2.5 mL of red latex solution was injected to identify the position of the needle tip. The division and distribution of the sensory branches originating from the SSN were described. RESULTS: The tip of the needle was identified at 1.3 cm (range, 0-5.2 cm) and 1.5 cm (range, 0-4.5 cm) with USRA and the LBA, respectively (P = .90). Staining diffused past the origin of the most proximal sensory branch in 27 cases. The most proximal sensory branch arose 2.5 cm from the suprascapular notch. Among the 3 failures that occurred in the USRA group, the sensory branches also failed to be marked. All 30 dSSNs gave off 3 sensory branches, which innervated the posterior glenohumeral capsule, the subacromial bursa, and the coracoclavicular and acromioclavicular ligaments. CONCLUSIONS: An LBA is as reliable and accurate as US guidance for anesthetic blockade of the dSSN. Marking of the suprascapular nerve must be proximal to the suprascapular notch to involve the 3 sensory branches in the anesthetic blockade. CLINICAL RELEVANCE: The present study demonstrates that a landmark-based approach to anesthetic blockade of the distal suprascapular nerve is accurate and can be performed by orthopaedic surgeons lacking experience in ultrasound-guided anesthetic techniques.

Sensory innervation of the subacromial bursa by the distal suprascapular nerve: a new description of its anatomic distribution.

BACKGROUND: Sensory innervation to the shoulder provided by the distal suprascapular nerve (dSSN) remains the subject of debate. The purpose of this study was to establish consensus with respect to the anatomic features of the sensory branches of the dSSN. The relevant hypothesis was that the dSSN would give off 3 sensory branches providing innervation to the posterior glenohumeral (PGH) capsule, the subacromial bursa, in addition to the coracoclavicular and acromioclavicular ligaments. METHODS: The division, course, and distribution of the sensory branches that originated from the dSSN and innervated structures around the shoulder joint were examined macroscopically by dissecting 37 shoulders of 19 fresh-frozen cadavers aged of 83.0 years (range, 74-98 years). RESULTS: The 37 dSSN provided 1 medial subacromial branch (MSAb), 1 lateral subacromial branch (LSAb), and 1 PGH branch (PGHb) to the shoulder joint. This arrangement allowed for bipolar-MSAb and LSAb-innervation of the subacromial bursa, acromioclavicular (MSAb and LSAb) and coracoclavicular (MSAb) ligaments, as well as the PGH capsule (PGHb). CONCLUSIONS: The dSSN provided 2 subacromial branches and 1 PGHb to the shoulder joint. This arrangement allowed for bipolar-MSAb and LSAb-innervation of the subacromial bursa, acromioclavicular and coracoclavicular ligaments, as well as the PGH capsule.

Distal suprascapular nerve block-do it yourself: cadaveric feasibility study.

BACKGROUND: A bone landmark-based approach (LBA) to the distal suprascapular nerve (dSSN) block is an attractive "low-tech" method available to physicians with no advanced training in regional anesthesia or ultrasound guidance. The primary aim of this study was to validate the feasibility of an LBA to blockade of the dSSN by orthopedic surgeons using anatomic analysis. The secondary aim was to describe the anatomic features of the sensory branches of the dSSN. MATERIALS AND METHODS: An LBA was performed in 15 cadaver shoulders by an orthopedic resident. Then, 10 mL of methylene blue-infused 0.75% ropivacaine was injected around the dSSN; 2.5mL of red latex solution was also injected to identify the position of the needle tip. The division and distribution of the sensory branches that originate from the suprascapular nerve were described. RESULTS: The median distance between the dSSN and the site of injection was 1.5 cm (0-4.5 cm). The most common injection site was at the proximal third of the scapular neck (n = 8). Fifteen dSSNs were stained proximal to the origin of the most proximal sensory branch. All 15 dSSNs gave off 3 sensory branches that innervated the posterior glenohumeral capsule, the subacromial bursa, and the coracoclavicular and acromioclavicular ligaments. CONCLUSIONS: An LBA for anesthetic blockade of the dSSN by an orthopedic surgeon is a simple, reliable, and accurate method. Injection close to the suprascapular notch is recommended to involve the dSSN proximally and its 3 sensory branches.

Geometric modification of the humeral position after total reverse shoulder arthroplasty: what is the optimal lowering of the humerus?

BACKGROUND: The main mechanical effect after reverse shoulder arthroplasty (RSA) is the lowering of the glenohumeral rotation center. The optimal value of the humeral lowering after RSA is still debated. The main objective of our study was to determine the lowering and medialization of the humerus and to correlate these parameters with short-term functional results. MATERIALS AND METHODS: The study included 70 patients with complete radiographic and clinical data. A multivariate analysis was used to compare the clinical and radiographic outcomes with the humeral lowering. RESULTS: The mean humeral lowering was 25.4 mm (range, 6-38 mm), and the mean medialization was 9.2 mm (range, 0-20 mm). Humeral lowering significantly influenced active forward elevation and the rate of scapular notching. DISCUSSION: The best clinical results and the lowest incidence of scapular notching were found after a lowering of more than 24 mm in our series. We recommend humeral lengthening of at least 24 mm after implanting a total reverse shoulder prosthesis.

Reproducibility of a new method for measuring lowering and medialisation of the humerus after reverse shoulder arthroplasty.

BACKGROUND: Reverse shoulder arthroplasty (RSA) requires lowering the humerus and medialisation of the centre of rotation. Several techniques based on standard X-rays are available in the literature. The aim of this study was to expose and validate a new technique for measuring these parameters. MATERIALS AND METHODS: Radiographic data of 20 patients were included. Three observers examined each X-rays three times to establish the inter- and intra-reproducibility of each technique (Jobin, Renaud and our method). RESULTS: Intra-observer reproducibility was between 0.10 and 0.94. The best intra-observer intraclass correlation coefficient (ICC) was obtained using Renaud's and our techniques. The inter-observer reproducibility was between 0.37 and 0.74. The best inter-observer ICC was obtained with our technique. DISCUSSION: We describe a reliable and reproducible method to evaluate lowering and medialisation of the humerus after RSA. This technique may allow determine the optimal threshold of lengthening after RSA.

In-Office Biceps Tenotomy with Needle Arthroscopy: A Feasibility Study.

Isolated pathology of the long head of the biceps is an indication for biceps tenotomy. To date, needle arthroscopy allows a direct diagnosis of shoulder lesion. We aimed to evaluate the technical feasibility of an in-office biceps isolated tenotomy by needle arthroscopy. Advantages were found in the fast-track process and the high rate of satisfaction in our selected patients. It was also a way to correct the diagnosis of torn biceps missed by the imaging. However, performing this procedure requires previous experience in conventional arthroscopy and should not be performed on anxious patients. Further studies will be necessary to confirm the reproducibility of this promising method, which could be a valuable alternative to heavy in-operating room process.

The distal-medial pilot hole: A simple way to ease volar plate positioning in extra-articular distal radius fractures.

Volar plating is one of the most used surgical treatments for dorsally displaced extra-articular distal radius fractures. However, the reduction of the dorsal tilt can be difficult. It usually requires a flexion maneuver of the wrist while maintaining and screwing the plate, which is cumbersome. Plate positioning also is a crucial step and is sometimes difficult because of the large size of the plate relative to the width of the distal radius. We use an epiphysis-first technique. We place all the epiphyseal screws before reduction, and then we take advantage of the anatomical shape of a locking plate to automatically reduce the dorsal tilt by fixing the proximal radius to the plate with cortical compression screws. To ensure easy and accurate positioning of the plate, we drill a distal medial pilot hole in a free-hand fashion 10 mm proximal to the watershed line and 10 mm lateral to the medial rim of the radius, without positioning the plate. This allows a clear view of the location of this first hole. The locking plate is then applied to the distal radius with help of a monocortical non-locking screw, and it is controlled under fluoroscopy. When this medial pilot hole is properly positioned and the plate correctly tilted on the anteroposterior view, the remaining epiphyseal holes are filled with locking screws. Then the plate is fixed on the proximal radius with bicortical compression screws, allowing an automatic reduction of the epiphyseal dorsal tilt. We believe this technique is a safe and reproducible way to position volar plates and to reduce anatomically the dorsal tilt in extra-articular posteriorly displaced distal radius fractures (AO A2 and A3). Furthermore, the automatic fracture reduction provided by this technique decreases operation time and radiation.

Towards symmetry driven and nature inspired UV filter design.

In plants, sinapate esters offer crucial protection from the deleterious effects of ultraviolet radiation exposure. These esters are a promising foundation for designing UV filters, particularly for the UVA region (400 - 315 nm), where adequate photoprotection is currently lacking. Whilst sinapate esters are highly photostable due to a cis-trans (and vice versa) photoisomerization, the cis-isomer can display increased genotoxicity; an alarming concern for current cinnamate ester-based human sunscreens. To eliminate this potentiality, here we synthesize a sinapate ester with equivalent cis- and trans-isomers. We investigate its photostability through innovative ultrafast spectroscopy on a skin mimic, thus modelling the as close to true environment of sunscreen formulas. These studies are complemented by assessing endocrine disruption activity and antioxidant potential. We contest, from our results, that symmetrically functionalized sinapate esters may show exceptional promise as nature-inspired UV filters in next generation sunscreen formulations.

Peripheral Nerve Injury Associated with a Subdermal Contraceptive Implant: Illustrative Cases and Systematic Review of Literature.

BACKGROUND: Despite demonstrable safety and efficacy of subdermal contraceptive implants (SCIs), both insertion and removal of SCIs in the arm have been associated with neurovascular complications. The aim of this study was to investigate type and prognosis of nerve injuries associated with SCIs. METHODS: We performed a comprehensive search of 4 electronic databases for studies pertaining to patients with nerve injury and concurrent SCI. Studies published between January 1987 and June 2017 were included. Implant location, damaged nerves, clinical presentation, preoperative imaging (x-ray, ultrasound, magnetic resonance imaging), neurologic evaluation (nerve conduction studies, electromyography), and treatment methods were reviewed. To outline management strategies, 2 illustrative cases of major nerve injury caused by SCI removal were presented. RESULTS: We analyzed 10 studies including 12 patients. Fourteen nerve injuries in 12 patients were reported during SCI insertion (n = 1) and removal (n = 11). Medial antebrachial cutaneous (n = 5) and median (n = 5) nerves were primarily affected. Neuropathic pain was the main symptom. Primary reasons for nerve injury were pulling or grasping of the nerve (n = 9) after mistaking it for the implant. Neurapraxia (n = 7) was the most common lesion and was treated with implant removal and clinical surveillance (n = 6). Five patients completely recovered; the remaining patients continued to have motor and/or sensory deficit at mean follow-up of 0.7 year (range, 0-2 years). CONCLUSIONS: Nerve injuries related to SCIs are rare but potentially serious. For nonpalpable SCIs, a multidisciplinary approach, including practitioners with experience treating peripheral nerve injuries, is invaluable.

Management of septic non-union of the tibia by the induced membrane technique. What factors could improve results?

INTRODUCTION: Management of septic non-union of the tibia requires debridement and excision of all infected bone and soft tissues. Various surgical techniques have been described to fill the bone defect. The "Induced Membrane" technique, described by A. C. Masquelet in 1986, is a two-step procedure using a PMMA cement spacer around which an induced membrane develops, to be used in the second step as a bone graft holder for the bone graft. The purpose of this study was to assess our clinical and radiological results with this technique in a series managed in our department. MATERIAL AND METHOD: Nineteen traumatic septic non-unions of the tibia were included in a retrospective single-center study between November 2007 and November 2014. All patients were followed up clinically and radiologically to assess bone union time. Multivariate analysis was used to identify factors influencing union. RESULTS: The series comprised 4 women and 14 men (19 legs); mean age was 53.9 years. Vascularized flap transfer was required in 26% of cases before the first stage of treatment. All patients underwent a two-step procedure, with a mean interval of 7.9 weeks. Mean bone defect after the first step was 52.4mm. The bone graft was harvested from the iliac crest in the majority of cases (18/19). The bone was stabilized with an external fixator, locking plate or plaster cast after the second step. Mean follow-up was 34 months. Bony union rate was 89% (17/19), at a mean 16 months after step 2. Eleven patients underwent one or more (mean 2.1) complementary procedures. Severity of index fracture skin opening was significantly correlated with union time (Gustilo III vs. Gustilo I or II, p=0.028). A trend was found for negative impact of smoking on union (p=0.06). Bone defect size did not correlate with union rate or time. DISCUSSION: The union rate was acceptable, at 89%, but with longer union time than reported in the literature. Many factors could explain this: lack of rigid fixation after step 2 (in case of plaster cast or external fixator), or failure to cease smoking. The results showed that the induced membrane technique is effective in treating tibial septic non-union, but could be improved by stable fixation after the second step and by cessation of smoking. LEVEL OF EVIDENCE: IV, Retrospective study.

The influence of alcohol, propylene glycol and 1,2-pentanediol on the permeability of hydrophilic model drug through excised pig skin.

Alcohol and glycol including 1,2-pentanediol, a new product in this field, were examined for their transdermal penetration enhancing in vitro properties using pig skin and caffeine as a model drug. In order to investigate a possible influence of these compounds, we followed diffusion from an aqueous solution with caffeine followed by a series of different vehicles, their compositions were: (1) in water as a control; (2) in propylene glycol/ethanol/water (25:25:48; v/v/v); (3) in 1,2-pentanediol/water (2.5:95.5, v/v); (4) in 1,2-pentanediol/water (5:93, v/v); in propylene glycol/water (5:93; v/v); and in ethanol/water (5:93; v/v). The stratum corneum/vehicle partition coefficients (K(m)), maximum flux (J), enhancement factor (EF), 24-h receptor concentration (Q(24h)) were determined and compared to control values (caffeine in water). Permeation was also expressed in percentage of the applied dose absorbed in the different compartments. In all test models, caffeine was released and penetrated into pig skin. The 1,2-pentanediol was presented as the most effective enhancer; with a low proportion of this compound (only 5%), caffeine penetrated the skin quicker and in a greater extent. While this compound showed promise as penetration enhancer, further study was required to determine its effectiveness with others drugs and its irritation potential.

Irradiation of skin and contrasting effects on absorption of hydrophilic and lipophilic compounds.

Increasing legal requirements for risk assessment and efficacy testing in the dermo-cosmetic field have led to the development of alternative test methods. In this study, the porcine skin model was chosen to test the effect of irradiation on the penetration habits of UV filters and caffeine. For decades, the pig has been recognized as an experimental animal in biomedical research thanks to its morphological and physiological similarities to humans. In this study, we wanted to investigate the effect of UV irradiation on the absorption of octocrylene (OC) and benzophenone-3 (B3) sunscreens used under those circumstances and a model hydrophilic molecule, caffeine (Caf). These particular compounds were chosen due to their different lipophilic profiles. The percutaneous penetration of the two UV filters and Caf was studied after two simulated solar radiation doses of 61.4 kJ m(-2). After irradiation simulation, the total absorbed dose was increased for OC while for B3 and Caf it was lower. Thus, modifications in percutaneous absorption have been observed, and it appears that UV could play a crucial role in this process. Moreover, it has been observed that the lipophilic profile of the studied compounds affects percutaneous penetration when irradiated.