A Novel Surgical Treatment Management Algorithm for Elbow Posterolateral Rotatory Instability (PLRI) Based on the Common Extensor Origin Integrity.

Background: Here, we introduce a comprehensive treatment algorithm for posterolateral rotatory instability (PLRI) of the elbow, a condition affecting elbow mobility. We outline a diagnostic approach and a novel surgical management plan through the arthroscopic surgeon's point of view. Methods: The central focus of this management approach is the integrity of common extensor origin (CEO). High clinical suspicion must be evident to diagnose PLRI. Special clinical and imaging tests can confirm PLRI but sometimes the final confirmation is established during the arthroscopic treatment. The most appropriate treatment is determined by the degree of CEO integrity. Results: The treatment strategy varies with the CEO's condition: intact or minor tears require arthroscopic lateral collateral ligament imbrication, while extensive tears may need plication reinforced with imbrication or, in cases of retraction, a triceps tendon autograft reconstruction of the lateral ulnar collateral ligament alongside CEO repair. These approaches aim to manage residual instability and are complemented using a tailored rehabilitation protocol to optimize functional outcomes. Conclusion: PLRI is a unique clinical condition and should be treated likewise. This algorithm offers valuable insights for diagnosing and treating PLRI, enhancing therapeutic decision-making.

CT Arthrography of the Elbow: What Radiologists Should Know.

Computed tomography (CT) arthrography is a quickly available imaging modality to investigate elbow disorders. Its excellent spatial resolution enables the detection of subtle pathologic changes of intra-articular structures, which makes this technique extremely valuable in a joint with very tiny chondral layers and complex anatomy of articular capsule and ligaments. Radiation exposure has been widely decreased with the novel CT scanners, thereby increasing the indications of this examination. The main applications of CT arthrography of the elbow are the evaluation of capsule, ligaments, and osteochondral lesions in both the settings of acute trauma, degenerative changes, and chronic injury due to repeated microtrauma and overuse. In this review, we discuss the normal anatomic findings, technical tips for injection and image acquisition, and pathologic findings that can be encountered in CT arthrography of the elbow, shedding light on its role in the diagnosis and management of different orthopedic conditions. We aspire to offer a roadmap for the integration of elbow CT arthrography into routine clinical practice, fostering improved patient outcomes and a deeper understanding of elbow pathologies.

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.

Look for the POLESTAR (POstero-Lateral Engagement of Soft Tissue and Radial Head) while navigating around elbow dislocation.: CT scan analysis of elbow dislocation patterns.

INTRODUCTION: Elbow dislocation is frequently associated with bony and osteochondral postero-lateral capitellar lesions that are often under-reported. We aim to examine the radiological signs of postero-lateral lesions on Computer 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, 4) terrible triad defined as elbow dislocation with concomitant coronoid and a radial head fracture with a more important involvement. Patients with a more complex fracture pattern were excluded. The presence of POstero Lateral Engagement of Soft Tissue And the Radial head (POLESTAR) patterns was analyzed and subclassified as impaction type or fragmentation type. RESULTS: 51 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%, while 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, while fragmentation type is more frequent in grades 1 or 2.

A low carrying angle is measured in elite tennis players just before ball impact during the forehand, suggesting a dynamic varus instant accommodation moving towards full extension.

PURPOSE: The goal of this study was to use image analysis recordings to measure the carrying angle of elite male tennis players during the forehand stroke, with the hypothesis that elite tennis players overstress their elbow in valgus over the physiological degree in the frontal plane just before ball contact on forehand groundstrokes. METHODS: The carrying angle of male tennis players ranked in the top 25 positions in the ATP ranking was measured on selected video frames with the elbow as close as possible to full extension just before the ball-racket contact in forehands. These frames were extracted from 306 videos professionally recorded for training purposes by a high-profile video analyst. All measures were conducted by three independent observers. RESULTS: Sixteen frames were finally included. The mean carrying angle was 11.5° ± 4.7°. The intraclass correlation coefficient value was 0.703, showing good reliability of the measurement technique. The measured carrying angle was lower than what has been observed in historical cohorts using comparable measurement methodology, suggesting a possible instant varus accommodation mechanism before hitting the ball. CONCLUSIONS: The observed decrease in the carrying angle is a consequence of an increase in elbow flexion position dictated by the transition from a closed to open, semi-open stances. As the elbow flexes during the preparation phase, it is less constrained by the olecranon and its fossa, increasing the strain on the medial collateral ligament and capsule structures. Moving towards full extension before the ball-racket contact, the elbow is dynamically stabilised by a contraction of the flexor muscles. These observations could provide a new explanation for medial elbow injuries among elite tennis players and drive specific rehabilitation protocols. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level IV.

Semiquantitative index of symptomatic minor instability of the lateral elbow at CT arthrography (SMILE index): clinical applicability and reproducibility study.

OBJECTIVE: To assess the applicability of a semiquantitative index for symptomatic minor instability of the lateral elbow (SMILE). MATERIALS AND METHODS: CT arthrograms of consecutive patients with lateral elbow pain who underwent ultrasound-guided CT arthrography at our orthopedic center between April 2019 and May 2022 were included. Images were acquired at 100 kVp and 80 mAs. An expert radiologist (R1) and a radiology resident (R2) retrospectively performed an independent, blinded evaluation of the arthrograms to assess the presence of imaging findings suggestive of elbow instability. The SMILE index (0-8) was obtained adding (I) radial head chondromalacia (0 - 1); (II) humeral capitellum chondromalacia (0 - 1); (III) humeral trochlear ridge chondromalacia (0 - 1); (IV) annular ligament laxity (0 - 2); (V) synovial thickening (0 - 1); (VI) humeroradial joint asymmetry (0 - 1); and (VII) capsular tear (0 - 1). R1 repeated the assessment after 14 days. Cohen's weighted κ statistic and raw concordance were used to appraise reproducibility. RESULTS: Eighty patients (median age 49 years, interquartile range 40-53 years, 49, 61% males) underwent CT arthrography at our center, and 10 (12%) of them underwent bilateral elbow examination, leading to 90 included CT arthrograms. Median SMILE index was 4 (IQR: 2-5) for R1, 4 (IQR: 2-5) for R2, and 4 (IQR: 2-5) for the second assessment by R1. Intra-reader agreement was excellent (κ = 0.94, concordance 87%), while inter-reader agreement was substantial (κ = 0.75, concordance 67%). CONCLUSION: The proposed SMILE index showed good reproducibility; further studies are warranted to correlate our index with clinical and surgical data. CLINICAL RELEVANCE STATEMENT: Our scoring system allows a standardized evaluation of patients with lateral elbow pain and instability suitable for application into clinical practice, complementing the orthopedic surgeon's clinical diagnosis with imaging findings that may aid treatment choices. KEY POINTS: • Lateral elbow pain is often interpreted clinically as lateral epicondylitis, but it can also encompass intra-articular pathology. • The proposed arthrographic index allows comprehensive quantification of lateral elbow pathology with good reproducibility and application times. • Our index provides the orthopedic surgeon with information regarding intra-articular findings, aiding treatment choices.

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.

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.

Traumatic acute stem rupture in stress shielding bone resorption of a bipolar radial head arthroplasty: case report and literature review.

Bone resorption around the proximal portion of the stem of a radial head prosthesis is a frequent phenomenon. In the vast majority of cases it is not correlated with to be without clinical manifestations.  This radiographic sign, refers to the stress shielding effect has been more described in total hip replacement surgery. Few authors have noticed this phenomenon in radial head replacement. however, given the increasing number of these procedures, a careful surveillance is required in patients presenting this sign. We report a literature review and a case presentation of proximal stem rupture following a trauma in association to radiological periprosthetic bone resorption due to stress shielding and treated with revision surgery.

Overuse-related instability of the elbow: the role of CT-arthrography.

The elbow is a complex joint whose biomechanical function is granted by the interplay and synergy of various anatomical structures. Articular stability is achieved by both static and dynamic constraints, which consist of osseous as well as soft-tissue components. Injuries determining instability frequently involve several of these structures. Therefore, accurate knowledge of regional anatomy and imaging findings is fundamental for a precise diagnosis and an appropriate clinical management of elbow instability. This review focuses particularly on the varied appearance of overuse-related elbow injuries at CT-arthrography.

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.

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.

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.

Lateral Elbow Laxity Is Affected by the Integrity of the Radial Band of the Lateral Collateral Ligament Complex: A Cadaveric Model With Sequential Releases and Varus Stress Simulating Everyday Activities.

BACKGROUND: An elongation of the radial lateral collateral complex (R-LCL) can provoke symptomatic minor instability of the lateral elbow leading to lateral elbow pain. Biomechanical models investigating the effects of elongation and partial or complete lesions of the R-LCL on lateral elbow stability are lacking. PURPOSE: To evaluate how partial and complete R-LCL release affects radiocapitellar joint stability in a setting of controlled varus load and progressive soft tissue release. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen cadaveric specimens were obtained and mounted on a custom-made support to control elbow flexion and extension and to allow for controlled varus loading. Stress tests were performed on all intact specimens under gravity load alone, a 0.5-kg load applied to the hand, and a 1-kg load applied to the hand. After load application, anteroposterior radiographs were obtained. The following release sequence was applied to all specimens: release of the anterior half of the common extensor origin, pie crusting of the R-LCL, and R-LCL release. After each release, stress tests and radiographs were performed. The varus joint angulation of the elbow (α) was measured by 2 examiners as the main outcome parameter. RESULTS: Significant changes in α from the initial condition occurred after each release, and a significant effect of varus load on α was documented for all release steps. A significant effect of the releases on α could be documented for all identical varus load conditions. A linear regression model was generated to describe the effect of varus load on α. CONCLUSION: Varus loads simulating everyday activities produce changes in the varus joint angulation of the elbow already in the intact specimen, which are linearly dependent on the applied moment and persist after release of the lateral stabilizing structures. With progressive load, a pie crusting of the R-LCL is the minimal procedure able to provoke a significant change in the varus joint angulation, and a complete R-LCL release produces additional increase in the varus joint angulation in all testing conditions. CLINICAL RELEVANCE: These findings confirm the role of the R-LCL as static lateral stabilizer, supporting a pathological model based on its insufficiency and culminating with a symptomatic minor instability of the lateral elbow.

Growth Modulation by Stimulating the Growth Plate: A Pilot Study.

This study investigates the ability of low-intensity pulsed ultrasound (LIPUS) or direct injection of recombinant growth hormone (rGH) to stimulate local growth of long bones. In a randomized controlled animal trial, healthy immature rabbits were allocated to 1 of the following 4 conditions: epiphyseal rGH periosteal injection, transdermal LIPUS, saline periosteal injection, or no treatment. New bone deposition was labeled with calcein at days 1 and 18, and microscopic measurements of growth were conducted by blinded observers. Statistically significant differences in growth were observed between the LIPUS and rGH stimulated legs compared with contralateral control legs (35% p = 0.04 and 41% p = 0.04, respectively); whereas no difference was observed between the 4 control groups (p = 0.37). There was no evidence of physeal bar formation, suggesting that direct injection of rGH and application of LIPUS around the distal femoral physis in rabbits may have a positive effect on microscopic growth without short-term adverse sequelae.

Evaluation of the subscapularis split created with passive rotation during arthroscopic dynamic anterior stabilization (DAS): A cadaveric study.

INTRODUCTION: The purpose of the present study was to analyze the ability to create a subscapularis split by passive rotation of the arm during dynamic anterior stabilization (DAS) and to analyze the new geometry of the long head of the biceps LHB. HYPOTHESIS: The hypothesis was that this passive simple technique can create subscapularis split without additional dissection giving rise to new position of LHB with a new stabilization function. MATERIAL AND METHODS: A technique of subscapularis split using the LHB was used in 12 fresh-frozen human cadaveric shoulders. A subscapularis split was created by passive rotation of the arm after the LHB is shuttled into the joint during DAS. The length of the subscapularis split, post-DAS position and length of the LHB, and the angulation of the LHB relative to bicipital groove were measured after DAS and if this new geometry can give a new dynamic effect on subscapularis muscle. RESULTS: The mean length of the subscapular split after maximal rotation was 20.4±6.0mm (range: 10-32mm). The mean elongation of the LHB was 0.6±1.4mm (range: -1 to +3mm). The final angle of the LHB relative to the bicipital groove was 45±5 degrees (range: 41 to 55 degrees). DISCUSSION: There is no need to create a distinct split prior to DAS. Additionally, DAS maintains the length-tension relationship of the LHB. The post-procedure medial angulation of the LHB relative to the bicipital groove may provide a lowering of the subscapularis, helping explain the anterior reinforcement of this technique. LEVEL OF EVIDENCE: Basic science study, cadaver study.

Validation of the cross-cultural adapted Italian version of the Oxford Elbow Score.

BACKGROUND: The Oxford Elbow Score (OES) is an English-language questionnaire specifically designed to evaluate surgical elbow outcomes. This scoring system has been translated into other languages. Given the lack of an Italian version of the OES, the present study was designed to establish, culturally adapt, and validate the Italian version. METHODS: The OES questionnaire was culturally adapted to Italian patients in accordance with the literature guidelines with a pilot phase including seven patients with elbow problems and seven healthy subjects. The study includes 110 participants from three hospitals, who underwent elbow surgery for acute (70%) or chronic diseases. At least one month after elbow surgery, at the "index visit", the physician completed the Mayo Elbow Performance Index and patients completed the following questionnaires: the Italian OES, the shortened version of the Disability of Arm, Shoulder and Hand Questionnaire (QuickDASH) and the Short-Form 36 Health Survey. Internal consistency was evaluated using Cronbach's alpha. Reproducibility was assessed using the intraclass correlation coefficient in ten patients who completed the OES again two-three days after the index visit. Construct validity was assessed using Spearman correlation coefficients. Responsiveness was evaluated in 68 patients who answered the questionnaires four months after the index visit, using the Wilcoxon signed-rank test, the effect size and the standardized response mean calculation. RESULTS: Cronbach's alpha was excellent: 0.86 (0.82-0.90) for OES pain, 0.92 (0.90-0.94) for OES function, and 0.90 (0.87-0.93) for OES social/psychological. The intraclass correlation coefficient was 0.94 (0.78-0.98) for OES pain, 0.91 (0.71-0.97) for OES function, 0.95 (0.83-0.98) for OES social-psychological and 0.93 (0.76-0.98) for OES total. The Spearman ρ was >0.7 for OES pain and QuickDASH, for OES function and both QuickDASH and Mayo Elbow Performance Index, and for OES social-psychological and QuickDASH. Regarding responsiveness, the mean of the changes between the two visits ranged from 33.9 for OES pain, to 44 points for OES function and OES social/psychological. The effect size and the standardized response mean were >0.8 for all OES domains. CONCLUSION: This study demonstrates that the Italian version of the OES, translated in accordance with the international standardized guidelines, is reliable, valid, and responsive in patients who have undergone elbow surgery.

Optimization of Meniscus Cell Transduction Using Lentivirus and Adeno-Associated Virus for Gene Editing and Tissue Engineering Applications.

OBJECTIVES: The utilization of viral vectors to deliver genes of interest directly to meniscus cells and promote long-term modulation of gene expression may prove useful to enhance meniscus repair and regeneration. The objective of this study was to optimize and compare the potential of lentivirus (LV) and adeno-associated virus (AAV) to deliver transgenes to meniscus cells in both intact meniscus tissue and isolated primary cells in monolayer. DESIGN: Porcine meniscus tissue explants and primary meniscus cells in monolayer were transduced with LV or self-complementary AAV2 (scAAV2) encoding green fluorescent protein (GFP). Following transduction, explants were enzymatically digested to isolate meniscus cells, and monolayer cells were trypsinized. Isolated cells were analyzed by flow cytometry to determine percent transduction. RESULTS: LV and scAAV2 showed a high transduction efficiency in monolayer meniscus cells. scAAV2 was most effective at transducing cells within intact meniscus tissue but the efficiency was less than 20%. Outer zone meniscus cells were more readily transduced by both LV and scAAV2 than the inner zone cells. Higher virus titers and higher cell density resulted in improved transduction efficiency. Polybrene was necessary for the highest transduction efficiency with LV, but it reduced scAAV2 transduction. CONCLUSIONS: Both LV and scAAV2 efficiently transduce primary meniscus cells but only scAAV2 can modestly transduce cells embedded in meniscus tissue. This work lays the foundation for viral gene transfer to be utilized to deliver bioactive transgenes or gene editing machinery, which can induce long-term and tunable expression of therapeutic proteins from tissue-engineered constructs for meniscus repair and regeneration.