Look for the POLESTAR (POsteroLateral Engagement of Soft Tissue And Radial head) while navigating around elbow dislocation.

BACKGROUND: Elbow dislocation is frequently associated with bony and osteochondral posterolateral capitellar lesions that are often under-reported. We aim to examine the radiologic signs of posterolateral lesions on computed tomography (CT). METHODS: A retrospective analysis of CT scans was performed. Patients were classified into 4 groups: (1) simple elbow dislocation, (2) elbow dislocation with a fracture of the coronoid tip, (3) elbow dislocation with coronoid tip fracture and a radial head fracture inferior or equal to the anterior third, and (4) terrible triad defined as elbow dislocation with concomitant coronoid and radial head fracture with a more important involvement. Patients with a more complex fracture pattern were excluded. The presence of POsteroLateral Engagement of Soft Tissue And Radial head (POLESTAR) patterns was analyzed and subclassified as impaction type or fragmentation type. RESULTS: Fifty-one CT scans met the inclusion criteria. POLESTAR lesions were identified in 48 cases (94%): 46% impaction-type and 54% fragmentation-type POLESTAR. Analyzing patients from grade 1 to 4, impaction-type POLESTAR was found, respectively, from 40% to 57%, whereas fragmentation type was present from 60% to 43%. CONCLUSIONS: This study shows a high incidence of POLESTAR lesions (94%) that can be present as impaction type or fragmentation type. Based on our preliminary results, impaction type is more common in grades 3 and 4, whereas fragmentation type is more frequent in grades 1 and 2.

Proximal radioulnar joint, but not posterolateral, instability in patients with symptomatic minor instability of the lateral elbow.

BACKGROUND: The elbow joint is stabilized laterally by a complex of bony and ligamentous structures, such as the lateral ulnar collateral ligament and radial lateral collateral ligament (RLCL). Pathogenesis of many elbow conditions like symptomatic minor instability of the lateral elbow (SMILE) is based on ligamentous incompetency. The aim of this study is to measure ligament elongation in SMILE patients and determine the correlation with the development of this pathologic condition. MATERIALS AND METHODS: Twenty-eight patients were included in this study: half of them were operated for suspected SMILE whereas the others were affected by other elbow diseases. All the patients underwent elbow arthroscopy. During this procedure, 4 parameters were analyzed: annular drive through (ADT), ulnar-humeral stressed distance (UHSD) at 45° and 30° of flexion, and loose collar sign (LCS). A dedicated arthroscopic mini-spreader introduced through an arthroscopic portal was used to take measurements. RESULTS: Statistically significant differences were found for LCS (P = .0003) and ADT (P = .000002). UHSD at 30° and 45° elbow flexion was slightly higher in SMILE patients, but not significantly. DISCUSSION AND CONCLUSIONS: Progressive stretching of the RLCL and annular ligament may lead to their elongation, resulting in a pathologic anteroposterior shifting of the radial head and a lower congruence between the inner surface of the annular ligament and the radial head cartilage, resulting in proximal radioulnar instability. The study shows how RLCL and annular ligament are elongated in SMILE patients compared with controls, causing instability of the proximal radioulnar joint and confirming that ligament incompetency is involved in the SMILE condition.

Anatomic relations of the median nerve to the ulnar insertion of the brachialis muscle: safety issues and implications for medial approaches to the elbow joint.

INTRODUCTION: Preventing nerve injury is critical in elbow surgery. Distal extension of medial approaches, required for coronoid fracture fixation and graft-replacement, may endanger the median nerve. This study aims to describe an easily identifiable and reproducible anatomical landmark to localize the median nerve distal to the joint line and to delineate how its relative position changes with elbow flexion and forearm rotation. MATERIALS AND METHODS: The median nerve and the ulnar insertion of the brachialis muscle were identified in eleven fresh-frozen cadaveric specimens after dissection over an extended medial approach. The elbow was brought first in full extension and then in 90° flexion, and the shortest distance between the two structures was measured while rotating the forearm in full pronation, neutral position and full supination. RESULTS: The distance between the median nerve and the brachialis insertion was highest with the elbow flexed and the forearm in neutral position. All distances measured in flexion were larger than those in extension, and all distances measured from the most proximal point of the brachialis insertion were larger than those from the most distal point. Distances in pronation and in supination were smaller than to those in neutral forearm position. CONCLUSIONS: The ulnar insertion of the brachialis is a reliable landmark to localize and protect the median nerve at the level of the coronoid base. Elbow flexion and neutral forearm position increase significantly the safety margins between the two structures; this information suggests some modifications to the previously described medial elbow approaches. LEVEL OF EVIDENCE: Basic Science Study.

Ultrasound evaluation shows increase in laxity after partial common extensor origin detachment but not after additional lesion of the radial band of the lateral collateral ligament.

PURPOSE: The lateral elbow musculature conveys a dynamic valgus moment to the elbow, increasing joint stability. Muscular or tendinous lesions to the anterior half of the common extensor origin (CEO) may provoke a deficiency in the elbow dynamic stabilizers, regardless of their traumatic, degenerative, or iatrogenic aetiology. Furthermore, a role for the radial band of the lateral collateral ligament (R-LCL) has been postulated in the aetiology of lateral elbow pain. This study aimed to evaluate the effects of sequential lateral releases with dynamic ultrasound, evaluating its capability to detect lesions of the CEO and of the R-LCL. METHODS: Ultrasound investigation of the lateral compartment of the elbow was performed on nine cadaveric specimens with a 10 MHz linear probe in basal conditions, after the release of the anterior half of the CEO and after complete R-LCL release. The lateral joint line widening (λ) was the primary outcome parameter, measured as the linear distance between the humeral and radial articular surfaces. RESULTS: The release of the anterior half of the CEO significantly increased λ by 200% compared to the starting position (p = 0.0008) and the previously loaded position (p = 0.0015). Conversely, further release of the R-LCL caused only a marginal, non-significant increase in λ. CONCLUSIONS: Ultrasound evaluation can detect changes related to tendon tears or muscular avulsions of the CEO and can depict lateral elbow compartmental patholaxity by assessing articular space widening while scanning under dynamic stress. However, it cannot reliably define if the R-LCL is injured. Iatrogenic damage to the CEO should be carefully avoided, since it causes a massive increase in compartmental laxity.

Greater trochanter fractures in the direct anterior approach: evolution during learning curve, risk factors and consequences.

INTRODUCTION: Greater trochanter (GT) fractures affect 0.6-29% of patients after direct anterior approach (DAA) total hip arthroplasty (THA). Given the growing popularity of this approach, this study aimed to assess the evolution of the GT fractures during the learning curve, their risk factors and their consequences. MATERIALS AND METHODS: 537 total hip arthroplasties were retrospectively included from May 2013 to December 2017 in a single academic centre. Patient characteristics, perioperative management, clinical consequences and postoperative radiographs were analysed. RESULTS: GT fractures represented 2.4% (n = 13) of the THA, and there was not a decrease with experience. The GT fracture patients did not require any additional support during the surgery, and full weight bearing was always allowed without any restriction. This complication only happened in females, with the risk significantly increased in those > 70 years old (OR = 4.9). There was no specific consequence during the follow-up, mean HHS score was 98.5 and all of the patients were satisfied or very satisfied postoperatively. CONCLUSION: Older osteoporotic women are known to be at risk for GT fracture during DAA THA. Those results reinforce the argument in favour of proper patient selection in DAA to lower the complications since it does not improve with surgeon's experience. LEVEL OF EVIDENCE: Retrospective, consecutive case series; Level IV.

Transitioning the total hip arthroplasty technique from posterior approach in lateral position to direct anterior approach in supine position-risk factors for acetabular malpositioning and the learning curve.

PURPOSE: Cup positioning is important for optimum hip stability, avoiding component impingement and decreasing both bearing surface wear and revision rate. Transitioning from posterior approach in a lateral position to direct anterior approach (DAA) in a supine presents unique challenges for surgeons. The aim of this study was to examine the learning curve when using standard instrumentation that was not specific to DAA. METHODS: A consecutive retrospective series of 537 total hip arthroplasty by DAA from May 2013 to December 2017. Cup positioning was analysed on radiographs and classified whether inside or outside two safe zones (inclination 30-50° and anteversion 10-30°). The demographic data (age, BMI, gender, neck shaft angle (NSA)), surgeon's dominant side and experience were assessed as risk factors. RESULTS: Eighty per cent of cups (n = 426) were in the combined safe zones. Eighty-eight per cent (n = 470) were in appropriate anteversion and 87% (n = 463) abduction. Two factors that were significant were identified: Cups of left hips operated by right-handed surgeons were more anteverted (OR = 4.06) and more vertical (OR = 2.23); females had a higher anteversion of the cup (OR = 2.42). Obesity, age and NSA were not risk factors for cup malposition. There was a spike of cups too horizontal at the beginning of the experience (OR = 3.86), and no learning curve was observed in the other orientations. CONCLUSION: With our DAA technique using standard instrumentation, there were no risk factors linked to the patient identified for cup malposition. DAA-specific instrumentation is not required to achieve optimum positioning of the cup. Surgeon has to be aware of an excess of abduction at the beginning of his experience and an excess of anteversion and adduction when performing THA on the opposite side of his dominant hand.

Effects of sagittal tibial osteotomy on frontal alignment of the knee and patellar height.

AIM OF THE STUDY: The aim of this study was to evaluate the radiographic effect of sagittal tibial osteotomy (STO), flexion tibial osteotomy (FTO) and deflexion tibial osteotomy (DTO) around the knee. It has been hypothesized that proximal STO modifies patellar height and could cause varus/valgus changes of the anatomical tibial axis: The purpose of the study was to verify this and to analyse these modifications. METHOD: Patients underwent proximal STO in our department between 2007 and 2018: overall 28 consecutive patients (19 males, 9 females; 28 knees). Twelve patients underwent DTO, and 16 patients underwent FTO. Two independent observers measured the pre-operative and post-operative radiological indexes: posterior tibial slope, Caton-Deschamps Index (CDI) and Modified Insall-Salvati Index (MISI) in the lateral views; medial Tibial Plateau-Tibial Shaft (mTPTS) and medial Femoral Shaft-Tibial Shaft (mFTA) anatomical angles were measured in the frontal plane. RESULTS: No complications were reported at the average follow-up of 1.6 ± 1.1 years. The mean mTPTS significantly increased from 0.6° ± 2.4° pre-operatively to 2.9° ± 2.6° of varus post-operatively (DTO (pre-operative 0.3 ± 3.1°, post-operative 2.4 ± 2.1°, ns); FTO (pre-operative 0.9 ± 1.9°, post-operative 3.2 ± 3.0°, P < 0.05)). The mean mFTA significantly reduced from 186.2° ± 4.9° pre-operatively to 182.7° ± 3.9° post-operatively (DTO (pre-operative 183.4 ± 3.3°, post-operative 180.6 ± 3.5°, ns); FTO (pre-operative 188.5 ± 4.9°, post-operative 184.4 ± 3.4°, P < 0.05)). The overall analysis reported no differences statistically significant in patellar height indexes. DISCUSSION: The main finding of this study is that STO slightly modifies tibial anatomical axes. This finding is more evident in FTOs. This surgical technique, due to its design, does not influence the patellar height. The tibial tuberosity osteotomy, performed in most of the cases to better expose tibial metaphysis and to avoid patellar tendon damages, provides another benefit that is the possibility to easily preserve the native patellar height. CONCLUSION: Sagittal tibial osteotomies slightly modify tibial anatomical axes in frontal plan without influencing the patellar height. This surgical procedure resulted to be effective and reliable in correcting the sagittal knee alignment but reporting, particularly of FTO, varus changes of anatomical tibial axis.

No neurovascular damage after creation of an accessory anteromedial portal for arthroscopic reduction and fixation of coronoid fractures.

PURPOSE: Arthroscopic reduction and internal fixation for coronoid process fractures has been proposed to overcome limitations of open approaches. Currently, arthroscopy is most frequently used to assist insertion of a retrograde guide wire for a retrograde cannulated screw. The present anatomical study presents an innovative arthroscopic technique to introduce an antegrade guide wire from an accessory anteromedial portal and evaluates its safety and reproducibility. METHODS: Six fresh-frozen cadaver specimens were obtained and prepared to mimic an arthroscopic setting. The coronoid process was localized and a 0.9 mm Kirschner wire was introduced from an accessory anteromedial portal, located 2 cm proximal to the standard anteromedial portal. At the end of the procedure, a lateral radiograph was taken to verify the Kirschner wire position and open dissection was conducted to evaluate possible damage to neurovascular structures. RESULTS: The Kirschner wire was drilled without complications in the coronoid process of all six specimens. Damage of the brachial artery, the median nerve, and the ulnar nerve did not occur in any specimen. A corridor between the brachialis muscle, the median intermuscular septum, and the pronator teres could be identified as suitable for the wire passage. CONCLUSION: This study presents a safe and reproducible technique combining the possibility to introduce a guide wire from the anteromedial part of the coronoid, under direct visual control, with a completely arthroscopic approach. This wire can guide the introduction of a retrograde cannulated screw from the dorsolateral ulna to the tip of the coronoid. This new arthroscopic approach permits to obtain improved visual control over coronoid process fixation, without endangering neurovascular structures.

Modified anteromedial and anterolateral elbow arthroscopy portals show superiority to standard portals in guiding arthroscopic radial head screw fixation.

PURPOSE: Arthroscopic fixation of radial head radial head fractures is an appealing alternative to open reduction and internal fixation, which presents the advantage of minimal surgical trauma. The aim of this study was to evaluate if modifications to the standard anteromedial (AM) and anterolateral (AL) portals could allow screw placement for radial head fracture osteosynthesis closer to the plane of the radial head articular surface. METHODS: Eight fresh-frozen specimens were prepared to mimic arthroscopic setting. Standard AL (ALst) and AM (AMst) and distal AL (ALdi) and AM (AMdi) portals were established. Eleven independent examiners were asked to indicate the optimal trajectory, when aiming to place a cannulated screw parallel to the radial head surface for radial head osteosynthesis. A three-dimensional digital protractor was used to measure the angle between the indicated position and a Kirschner wire placed parallel to the radial head articular surface (α). The Shapiro-Wilk normality test was used to evaluate the normal distribution of the samples. Means, standard deviations, and 95% confidence intervals (95% CI) were calculated for each portal. A coefficient of variation (CoV) was calculated to determine agreement among observers and intra-observer variability. RESULTS: Mean α angles were 25.1 ± 11.5° for AMst, 13.8 ± 4.8° for AMdi, 17.1 ± 13.4° for ALst, -2.6 ± 9.2° for ALdi. No overlapping in the 95% CI of ipsilateral standard and distal portals was observed, indicating that the difference between these means was statistically significant. The distal portals showed smaller inter-observer CoV as compared to the standard ones (AMst: 10.0%; AMdi: 4.6%; ALst: 12.5%; ALdi: 10.6%). Intra-observer CoV was similar for all portals (AMst: 5.5%; AMdi: 6.1%; ALst: 7.7%; ALdi: 7.1%). CONCLUSIONS: The use of distal AM and AL portals permits to obtain α angles closer to the radial head articular surface than standard AM and AL portals. This is expected to allow screw placement in a flatter trajectory, which should correlate with a superior biomechanical performance of fixation. Good reproducibility of Kirschner wire placement from distal portals was observer among different examiners. Modifications to the standard AM and AL elbow arthroscopy portals allow to place screws for radial head fracture osteosynthesis in a position which should guarantee superior biomechanical performance of fixation.

A combination of an anteromedial, anterolateral and midlateral portals is sufficient for 360° exposure of the radial head for arthroscopic fracture fixation.

PURPOSE: Arthroscopic fixation of radial head fractures is an alternative to open reduction and internal fixation; the latter, however, presents the advantage of minimal soft-tissue damage. The exposure of the radial head for adequate screw placement can be technically challenging. The aim of this study was to evaluate the inter-observer agreement on the effective contact arc in the axial plane of the radial head of three different elbow arthroscopy portals. METHODS: A fresh-frozen cadaver specimen was obtained and prepared in an arthroscopic setting. Standard anterolateral (AL), anteromedial (AM), and midlateral (ML) portals were established and a circular reference system was marked on the radial head. Ten orthopaedic surgeons were then asked to move the forearm from maximal supination to maximal pronation and indicate with a Kirschner wire from each portal the extension in which they would feel confident in placing a cannulated screw passing through the centre of the articular plane of the radial head (axial contact arc). The Shapiro-Wilk normality test was used to evaluate the normal distribution of the sample. A coefficient of variation (CoV) was calculated to determine agreement among observers. RESULTS: The average arc of axial contact arc that could be contacted from the AM portal measured 150 ± 14.1°, or 41.7% of the radial head circumference; the one from the AL portal measured 257 ± 29.5°, or 71.4% of the radial head circumference; that from the ML portal measured 212.5 ± 32.6°, or 59.0% of the radial head circumference. Considering all three portals, the whole radial head circumference could be contacted. The AM portal showed the smallest CoV (9.4%) as compared to the AL (11.5%), and the ML (15.3%) portals. CONCLUSIONS: With an appropriate use of the standard AL, AM, and ML portals, the whole radial head circumference can be effectively exposed for adequate fixation of radial head fractures. The contact arc of the AM portal presents the smallest variability among different observers and the AL portal shows a superiority in axial contact arc. This information is important for pre-operative planning, and helps to define the limits of arthroscopic radial head fracture fixation.

Locating the ulnar nerve during elbow arthroscopy using palpation is only accurate proximal to the medial epicondyle.

PURPOSE: Knowledge of ulnar nerve position is of utmost importance to avoid iatrogenic injury in elbow arthroscopy. The aim of this study was to determine how accurate surgeons are in locating the ulnar nerve after fluid extravasation has already occurred, and basing their localization solely on palpation of anatomical landmarks. METHODS: Seven cadaveric elbows were used and seven experienced surgeons in elbow arthroscopy participated. An arthroscopic setting was simulated and fluids were pumped into the joint from the posterior compartment for 15 min. For each cadaveric elbow, one surgeon was asked to locate the ulnar nerve solely by palpation of the anatomical landmarks, and subsequently pin the ulnar nerve at two positions: within 5 cm proximal and another within 5 cm distal of a line connecting the medial epicondyle and the tip of the olecranon. Subsequently, the elbows were dissected using a standard medial elbow approach and the distances between the pins and ulnar nerve were measured. RESULTS: The median distance between the ulnar nerve and the proximal pins was 0 mm (range 0-0 mm), and between the ulnar nerve and the distal pins was 2 mm (range 0-10 mm), showing a statistically significant difference (p = 0.009). All seven proximally placed pins (100%) transfixed the ulnar nerve versus two out of seven distally placed pins (29%) (p = 0.021). CONCLUSIONS: In a setting simulating an already initiated arthroscopic procedure, the sole palpation of the anatomical landmarks allows experienced elbow surgeons to accurately locate the ulnar nerve only in its course proximal to the medial epicondyle (7/7, 100%), whereas a significantly reduced accuracy is documented when the same surgeons attempt to locate the nerve distal to the medial epicondyle (2/7, 29%; p = 0.021). Current findings support the establishment of a proximal anteromedial portal over a distal anteromedial portal to access the anterior compartment after tissue extravasation has occurred with regard to ulnar nerve safety.

The posterior interosseous nerve crosses the radial head midline and increases its distance from bony structures with supination of the forearm.

BACKGROUND: This study investigated whether forearm movements change the relative position of the posterior interosseous nerve (PIN) with respect to the midline of the radial head (Rh) under direct arthroscopic observation. METHODS: The PIN was identified in 10 fresh frozen cadaveric specimens dissected under arthroscopy. The forearm was moved first in full pronation and then in full supination, and the displacement of the PIN from medial to lateral with respect to the midline of the Rh was recorded. The shortest linear distance between the nerve and the most anterior part of the Rh was measured with a graduated calliper inserted via the midlateral portal with the forearm in neutral position, full pronation, and full supination. RESULTS: The PIN was identifiable in all specimens. In all cases the PIN crossed the Rh midline with forearm movements, moving from medial in full pronation to lateral in full supination. The distance between the PIN and Rh is significantly greater in supination than in the neutral position and pronation (P = .0001). CONCLUSIONS: This study confirms that the PIN movement described in open surgery (medialization with pronation) also occurs during arthroscopy. The role of pronation in protecting the PIN in extra-articularprocedures is therefore confirmed. Supination, however, increases the linear distance between the PIN and Rh and should therefore be considered to increase the safe working volume whenever intra-articular procedures are performed on the anterolateral aspect of the elbow.

Complication rate in adult deformity surgical treatment: safety of the posterior osteotomies.

PURPOSE: The treatment of adult scoliosis is a challenge especially in patients over 50 years old with severe, rigid curves in whom the use of vertebral osteotomies may be necessary to correct the deformity. The aim the study was to analyse the perioperative complications related to vertebral osteotomies in elderly treated for spinal deformity. METHODS: We analysed 72 consecutive cases of kyphoscoliosis, we classify them according to Berjano-Lamartina classification. We divided patients into two groups: we only practised SPO and/or PO in patients that composed group A; we practised also PSO in patients that composed group B. We retrospectively analysed the perioperative complications and radiographical results. Average follow-up was 30 months. RESULTS: We had 50 cases of degenerative segment diseases (DSD) Type III, 13 Type IVa DSD and 9 Type IVb DSD. Mean age was 60.7 years old. Overall complication rate was 22.2 %. In group A, the complication rate was 16.9 % while in group B it was 46.2 %. Mean Cobb primary curve angle was 41.75° with average C7 plumb line (C7PL) of 4.49 cm, residual scoliosis after surgery was 15.41° and average C7PL of 2.08 cm, with statistically significant differences. CONCLUSIONS: Previous studies have shown increased complication rates with vertebral osteotomies in elderly patients, our experience support this evidence. Our study demonstrates a high incidence of intraoperative complication rate in elderly patients underwent a PSO. PSO is a demanding technique to be considered in very selected and motivated patients who must be carefully informed about the risks of the procedure.

Electric scooter-related orthopedic injuries: the experience of an Italian orthopedic center and literature review.

Background: With the increasing prevalence of electric scooters, a concomitant increase in the number of specific injuries, emergency department (ED) admissions and hospital admissions have been reported. Objectives: Analyze patient flow changes in the ED with a focus on e-scooter-related injuries through a case series and a comparison with the contemporary literature. Data sources: A systematic literature review was performed on Medline/PubMed and Embase using terms related to the topic.Data collected from two-wheeled vehicle trauma patients at our Italian ED from May 1 to October 31, 2021, were analyzed for the case series. Study eligibility criteria: Studies were included if they evaluated populations with an e-scooter-related injury referred to the ED with precise localization and nature of the injury reported. Participants and interventions: Data collected from the literature studies and from our case series included overall ED patient numbers, patient demographics, injury mechanism, location of the injury, discharge diagnosis, and performance of surgery. Study appraisal and synthesis methods: All studies were checked in order to establish the coherence with the purposes of this review. Data from the contemporary literature and from this case series were compared. Results: During a 6-month period, 280 patients had e-scooter injuries, resulting in 292 traumas, including 123 fractures, primarily in the elbow. Surgical intervention was necessary for 28 patients. The review included nine papers, highlighting that injuries to the upper and lower extremities and head were frequent in e-scooter-related incidents. The upper extremities were the most common fracture location. Limitations: The study is a retrospective, single-center study without a comparison group, focusing exclusively on orthopedic injuries. Conclusions or implications of key findings: The prevalence of electric scooters, which offer an affordable and eco-friendly mode of transport, is steadily increasing. It is important to focus on injury risk mitigation through effective public health policies, thereby lowering costs to society.

A 70° Arthroscope Provides Better Visualization of the Medial Side of the Elbow Than a 30° Arthroscope.

Purpose: To assess and quantify the improvement in visualization of humeral insertion of the medial collateral ligament (MCL) using a 70° scope compared with a 30° scope during elbow arthroscopy. Methods: Twenty patients undergoing elbow arthroscopy for different pathologic conditions were enrolled in this single-center study. Visualization of the medial gutter of the elbow was evaluated by using both the 70° and the 30°scope. During the procedure, a needle was inserted at 45° with respect to the axis of the forearm, directed toward the intra-articular humeral emergence of the MCL. Four areas were established: the body (Z1), the lanceolate part (Z2), the tip of the needle (Z3), and the medial portion of the trochlea (Z4). The visible areas during arthroscopy using 2 different scopes were collected. Results: The 70° scope allowed the detection of the first 3 areas in all patients (Z1, Z2, and Z3) and the visualization of the last area (Z4) in 19 patients (95%). On the other hand, the 30° scope allowed the detection of Z1 in 85% of patients, Z2 in 60% of patients, and Z3 in only 5% of patients. The medial portion of the trochlea was never visualized with the 30° scope. These findings were statistically significant. Conclusions: The 70° scope improves visualization of the medial elbow compartment during elbow arthroscopy compared to the 30° scope, enhancing the extent of joint visualization and potentially permitting the detection of otherwise missed injuries in the difficult-to-reach areas of the joint. Level of Evidence: Level II, diagnostic, prospective, cohort study.

Humeral trochlear morphology does not influence coronoid fractures in elbow dislocation.

PURPOSE: Traumatic elbow dislocation is the second most frequent joint dislocation, even though the elbow is a congruent and stable joint. Individual variability in anatomical congruence of the elbow and how it relates to simple or complex instability has rarely been studied in the literature; we hypothesized that a greater articular coverage by the humeral trochlea would be more likely to result in complex dislocation. The aim of this study is to analyze trochlear morphology in simple (SED) and complex elbow dislocation (CED), to assess whether the degree of humeroulnar joint congruence influences the incidence of coronoid fractures in elbow dislocation. The secondary goal is to evaluate the association between trochlear morphology and coronoid fracture pattern. METHODS: All the elbow CT scans of the hospital server were retrospectively analyzed. 62 patients were enrolled and so divided in 2 groups: SED and CED with isolated coronoid fracture. Patients who were skeletally immature, presented with other concomitant elbow fractures, or who previously underwent elbow surgery were excluded. The CT scans were performed after closed reduction and prior to further treatment. Coronoid fracture pattern was classified on CT scan according to Regan-Morrey and O'Driscoll classifications; "grade 0" was assigned to SED. Trochlear coverage was measured and expressed as three angles (anterior, posterior, and distal) and their width/depth ratios. Measurements were taken by four different readers and the assessment was repeated after 15 days. RESULTS: No statistically significant difference was found between humeral trochlear morphology of SED and CED patients. There was no association between morphometric measurements and coronoid fracture pattern. The results are strengthened by a good intra- and inter-reader reproducibility of the CT analysis protocol. CONCLUSIONS: Our study is the first to evaluate the impact of trochlear morphology on elbow instability. Considering the results, other variables may have a greater impact on coronoid bone damage, such as trauma energy or ligamentous hyperlaxity: in particular, we believe that the capsuloligamentous structures of the elbow might contribute in a preponderant way to articular stability. The CT analysis protocol gave excellent results: reproducible, accurate and easy to perform. LEVEL OF EVIDENCE: III.

The Dynamic Effect of Anterior Cruciate Ligament Deficiency on Patellar Height.

Background: The anterior tibial translation (ATT) in case of Anterior Cruciate Ligament (ACL) tear can lead to dynamic alterations of the extensor apparatus biomechanics. The aim of this study is to evaluate the dynamic effect of isolated ACL deficiency on patellar height. The hypothesis is that the ATT of ACL-insufficient knees dynamically reduces patellar height. Methods: Skeletally mature patients who underwent ACL reconstruction using hamstring graft between January and December 2018 were included in this study. The Posterior Tibial Slope (PTS), Caton-Deschamps (CDI), modified Insall-Salvati (MISI), and Blackburne-Peel (BPI) indices were calculated in standard lateral and TELOS X-rays. The mean of the measurements calculated between two observers was used to compare these parameters. Results: 95 patients (M: 57; F: 38; 95 knees) were included in the study with a mean age of 31.8 years (16-56 years old). Significant patellar height reduction (CDI: 0.11 [- 0.32; 0.31]; MISI: 0.09 [- 0.66; 0.30]) was reported in TELOS compared with standard lateral knee radiography (p < 0.001). 20.0% of the study knees reported an abnormal CDI and 84.2% (16/19 knees) of them reduced this index to within normal limits in TELOS. 20.0% of the knees with mild patella alta reduced CDI in TELOS but always remained above 1.2. Conclusions: The abnormal ATT in case of ACL-deficient knees results in a lowering effect of the patella in TELOS X-rays. In patients with ACL tear and anterior pain the reconstructive ligament surgery should be performed to avoid also chronic anterior knee pain. Level of evidence: Basic Science Study (Case Series). Clinical relevance: The decrease in patellar height in stress-X-rays compared with standard lateral knee radiography in ACL deficient knees, should be considered as a possible contributing cause of anterior pain in these patients.

Does Sawbone-Based Arthroscopy Module (SBAM) Can Help Elbow Surgeons?

INTRODUCTION: The use of elbow arthroscopy is becoming increasingly common in orthopaedic practice; nevertheless, it is still considered a difficult procedure with a long learning curve. The aim of the study is to evaluate the role of a new elbow Sawbone-Based Arthroscopy Module (e-SBAM) in the training of elbow surgeons. METHODS: Fourteen surgeons were classified as "Expert" (n: 7; more than 10 years of experience in arthroscopic surgery) and "Not-expert" surgeons (n: 7; less than 10 years of experience). During a dedicated arthroscopic session, using the Sawbones Elbow model (Sawbones Europe AB®), all participants were asked to perform an arthroscopic round and to touch three specific landmarks. An independent observer measured the time that each participant needed to perform this task (Performance 1). The same measurement was repeated after two weeks of eSBAM training (Performance 2). RESULTS: "Not-expert" surgeons needed significantly more time (41 s; range 26-120) than "Expert" ones (13 s; range 8-36) to complete Performance 1. One "Not-expert" surgeon did not complete Performance 1 and needed more than 120 s for Performance 2. The whole study group required a median of 5 s less to complete Performance 2. A tendency towards an improvement was observed in the group of the non-experienced surgeons as compared with the experienced ones. CONCLUSIONS: The simulation training can be advantageous in the learning curve of young elbow surgeons and helpful for experienced surgeons. E-SBAM can be used as an effective tool for the current stepwise arthroscopic elbow training programs with the aim of improving arthroscopic elbow skills. LEVEL OF EVIDENCE: Basic Science Study.

Novel Radiographic Indexes for Elbow Stability Assessment: Part A-Cadaveric Validation.

INTRODUCTION: Elbow bony stability relies primarily on the high anatomic congruency between the humeral trochlea and the ulnar greater sigmoid notch. No practical tools are available to distinguish different morphotypes of the proximal ulna and herewith predict elbow stability. The aim of this study was to assess inter-observer reproducibility, evaluate diagnostic performance and determine responsiveness to change after simulated coronoid process fracture for three novel elbow radiographic indexes. METHODS: Ten fresh-frozen cadaver specimens of upper limbs from human donors were available for this study. Three primary indexes were defined, as well as two derived angles: Trochlear Depth Index (TDI); Posterior Coverage Index (PCI); Anterior Coverage Index (ACI); radiographic coverage angle (RCA); olecranon-diaphisary angle (ODA). Each index was first measured on standardized lateral radiographs and subsequently by direct measurement after open dissection. Finally, a type II coronoid fracture (Regan and Morrey classification) was created on each specimen and both radiographic and open measurements were repeated. All measurements were conducted by two orthopaedic surgeons and two dedicated musculoskeletal radiologists. RESULTS: All three indexes showed good or moderate inter-observer reliability and moderate accuracy and precision when compared to the gold standard (open measurement). A significant change between the radiographic TDI and ACI before and after simulated coronoid fracture was observed [TDI: decrease from 0.45 ± 0.03 to 0.39 ± 0.08 (p = 0.035); ACI: decrease from 1.90 ± 0.17 to 1.58 ± 0.21 (p = 0.001)]. As expected, no significant changes were documented for the PCI. Based on these data, a predictive model was generated, able to identify coronoid fractures with a sensitivity of 80% and a specificity of 100%. CONCLUSION: New, simple and easily reproducible radiological indexes to describe the congruency of the greater sigmoid notch have been proposed. TDI and ACI change significantly after a simulated coronoid fracture, indicating a good responsiveness of these parameters to a pathological condition. Furthermore, combining TDI and ACI in a regression model equation allowed to identify simulated fractures with high sensitivity and specificity. The newly proposed indexes are, therefore, promising tools to improve diagnostic accuracy of coronoid fractures and show potential to enhance perioperative diagnostic also in cases of elbow instability and stiffness. LEVEL OF EVIDENCE: Basic science study. CLINICAL RELEVANCE: The newly proposed indexes are promising tools to improve diagnostic accuracy of coronoid fractures as well as to enhance perioperative diagnostic for elbow instability and stiffness.

Novel Radiographic Indexes for Elbow Stability Assessment: Part B-Preliminary Clinical Study.

INTRODUCTION: The coronoid process plays a key-role in preserving elbow stability. Currently, there are no radiographic indexes conceived to assess the intrinsic elbow stability and the joint congruency. The aim of this study is to present new radiological parameters, which will help assess the intrinsic stability of the ulnohumeral joint and to define normal values of these indexes in a normal, healthy population. METHODS: Four independent observers (two orthopaedic surgeons and two radiologists) selected lateral view X-rays of subjects with no history of upper limb disease or surgery. The following radiographic indexes were defined: trochlear depth index (TDI); anterior coverage index (ACI); posterior coverage index (PCI); olecranon-coronoid angle (OCA); radiographic coverage angle (RCA). Inter-observer and intra-observer reproducibility were assessed for each index. RESULTS: 126 subjects were included. Standardized lateral elbow radiographs (62 left and 64 right elbows) were obtained and analysed. The mean TDI was 0.46 ± 0.06 (0.3-1.6), the mean ACI was 2.0 ± 0.2 (1.6-3.1) and the mean PCI was 1.3 ± 0.1 (1.0-1.9). The mean RCA was 179.6 ± 8.3° (normalized RCA: 49.9 ± 2.3%) and the mean OCA was 24.6 ± 3.7°. The indexes had a high-grade of inter-observer and intra-observer reliability for each of the four observers. Significantly higher values were found for males for TDI, ACI, PCI and RCA. CONCLUSION: The novel radiological parameters described are simple, reliable and easily reproducible. These features make them a promising tool for radiographic evaluation both for orthopaedic surgeons and for radiologists in the emergency department setting or during outpatient services. LEVEL OF EVIDENCE: Basic Science Study (Case Series). CLINICAL RELEVANCE: The novel radiological parameters described are reliable, easily reproducible and become handy for orthopaedic surgeons as well as radiologists in daily clinical practice.