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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.

Resume Introduction Le but de cette etude est d’analyser la faisabilite d’un split passif du sous-scapulaire par rotation du bras lors d’une stabilisation anterieure dynamique (DAS pour « Dynamic anterior stabilization ») et d’analyser le nouveau cheminement du long chef du biceps brachial (LCB). Hypothese L’hypothese est que cette technique simple passive peut creer un split du sous-scapulaire sans discision supplementaire donnant lieu a une nouvelle position du LCB avec une fonction stabilisante. Materiel et methodes Une technique de split du sous-scapulaire utilisant le LCB a ete utilisee dans 12 epaules cadaveriques humaines fraichement congelees. Un split du sous-scapulaire est cree par rotation passive du bras apres que le LCB ait ete transporte dans l’articulation glenohumerale durant une DAS. La longueur du split du sous-scapulaire, la longueur du LCB et l’angulation du LCB par rapport a la gouttiere bicipitale ont ete mesurees pour evaluer si cette nouvelle geometrie peut donner un nouvel effet stabilisateur au sous-scapulaire. Resultats La longueur moyenne du split du sous-scapulaire apres rotation maximale est de 20,4 ± 6,0 mm (extremes de 10 a 32 mm). L’allongement moyen du LCB est de 0,6 ± 1,4 mm (extremes de −1 a +3 mm). L’angle final du LCB par rapport a la gouttiere bicipitale est de 45 ± 5 degres (extremes de 41 a 55 degres). Discussion Il n’est pas necessaire de creer activement un split lors d’une DAS. La DAS maintient la relation longueur–tension du LCB. L’angulation postoperatoire du LCB par rapport a la gouttiere bicipitale peut fournir un abaissement du sous-scapulaire, aidant a expliquer le renfort anterieur de cette technique. Niveau de preuve Recherche fondamentale, etude cadaverique.

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.

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.

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.

Elbow instability can occur as post-traumatic sequelae or due to chronic overuse syndromes. Patients with chronic instability classically present with pain, apprehension, or mechanical symptoms after movements that result in joint subluxation. Arthroscopic plication of R-LCL and aMCL is an innovative surgical technique that enables an anatomic and minimally invasive ligament retensioning. Arthroscopic assisted MCL plication is indicated in medial elbow pain with valgus instability. Arthroscopic plication of radial component of LCL is indicated in lateral elbow pain recalcitrant to at least 6 months of conservative treatment. Several arthroscopic signs of minor elbow instability should be assessed during the procedure and their negativization at the end of the procedure corresponds to a restored stability of the elbow.

Coronoid process (CP) fractures are relatively uncommon, yet critical injuries to recognize. Arthroscopic reduction and fixation of coronoid process has been proposed to overcome these limitations of open approaches. Currently, arthroscopy is used to assist insertion of retrograde guide wire for a retrograde cannulated screw. This method is widely used; however it is technically challenging to direct the guide wire from dorsal aspect of ulna towards the tip of the coronoid. This chapter describes a new surgical procedure for arthroscopic-assisted fracture reduction and fixation of coronoid fractures. A technical modification of a standard elbow portal (anteromedial) allows the surgeons to obtain a better working angle for reduction of these fractures without requiring a cruciate ligament guide. This new accessory anteromedial portal permits fixation of the CP fracture using a more perpendicular angulation to the fracture line as compared to a standard anteromedial portal. This approach also abolishes completely the need for an anterior incision and dissection of the elbow capsule.

Arthroscopic fixation of radial head fractures is a valid alternative to the classic open reduction and internal fixation; the technique provides encouraging results and shows progressively evolving indications. The whole radial head circumference can be adequately addressed with appropriate use of anterolateral, anteromedial, and midlateral portals. This chapter describes the advantages and disadvantages of each portal and provides practical advice to improve visualization to guarantee the safety of the procedure.

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.

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.

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.

A Symptomatic Minor Instability of the Lateral Elbow (SMILE) is a possible etiology of recalcitrant lateral elbow pain: in this condition, the deficiency of the radial band of the lateral collateral ligament as a static elbow stabilizer plays a relevant role, determining hypermobility of the radial head, chondral abrasions, and synovitis associated to intra-articular pain and tendinopathy of the extensor carpi radialis brevis associated to extra-articular pain.

Arthroscopic-assisted radial head and coronoid fracture fixation can be a valid alternative to the classic open reduction and internal fixation in selected fracture types. Arthroscopy improves visualization of the articular surfaces, permitting better understanding of the fracture’s morphology and more precise anatomical reduction. Nevertheless, compared to open surgery, some specific risks and pitfalls should be considered. This chapter provides a concise overview on the relevant advantages and disadvantages of each elbow arthroscopy portal in addressing radial head fractures with arthroscopic lag screw fixation and presents an innovative arthroscopic technique for antegrade direct reduction and retrograde fixation of coronoid process fractures through an accessory anteromedial portal.

Medial elbow instability is usually due to trauma or overload. Post-traumatic instability implies rupture of the medial collateral ligament (MCL); sometimes there are some associated injuries such as bone fractures or soft-tissue lesions (flexor-pronator muscles). When MCL becomes insufficient, pathological contacts between bony surfaces of the elbow may occur during valgus-stress activities.

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 ± 6.0 mm (range: 10–32 mm). The mean elongation of the LHB was 0.6 ± 1.4 mm (range: −1 to +3 mm). 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.

INTRODUCTION: The strength of forearm in pronation and supination (P/S) is an important clinical assessment during pre-operative examination as well as in post-operative evaluation. Many clinical trials concerning the measurement of forearm P/S strength were performed using a dynamometer fixed on the wall. The aim of this study was to bring out a simple and reliable technique for the measurement of P/S strength using a dynamometer manually supported and stabilized by an examiner. We hypothesized that there are no differences in evaluation of elbow P/S strength using the dynamometer fixed or the dynamometer stabilized by an operator in healthy people. METHODS: The study was performed on a cross-sectional cohort of 100 healthy subjects without any history of injuries or previous surgery of the upper limbs. Isometric forearm P/S strengths were measured on the dominant and non-dominant forearms, using the dynamometer fixed on a table, and using the same dynamometer kept by an operator. The measurements were repeated in triplicate at 45°, 90° and 120° of elbow flexion in both upper limbs for all patients. RESULTS: A total of 100 subjects (50 females, 50 males) were included in the study group. The mean age was 46.5 years (range 25–52 years). Female and male subjects showed no significant differences concerning the mean age (F/M ratio 0.50/0.50). The mean body mass index of all participants was 24.34 ± 3.66 kg/m(2). No significant statistics difference was reported between the P/S strength measured using the two detection methods in our study group (45°, 90° and 120° of elbow flexion and both upper limbs). CONCLUSION: The manually stabilized technique is a valid and reliable technique to assess the P/S strength of the forearm. This is a simple and effective method that may be reproduced in our daily clinical practice as well as in sportive practice.

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.

The Oxford Shoulder Instability Score (OSIS) is self-reported outcome measurement developed to evaluate shoulder instability taking into account also adaptive strategies. Valid, reliable, reproducible, and user-friendly translations of outcome measure instruments are needed to allow comparisons of international study results. The Italian translation and cultural adaptation of the OSIS were completed using a “translation–back translation” method and the final version was administered to a sample of 25 consecutive Italian-speaking patients. The psychometric properties of this adaptation were evaluated in terms of feasibility, reliability, construct validity, and responsiveness. No major differences occurred between the OSIS translations into Italian and back into English, and no content- or linguistic-related difficulties were reported. The Cronbach’s alpha for the total OSIS was 0.897. Intraclass correlation coefficient value for inter-rater reliability was 0.805, while for intra-rater reliability was 0.586. Spearman rank correlation coefficient between the OSIS and the Rowe score was 0.548 (p = 0.005) and between OSIS-I and SF-12 was 0.488 (p = 0.013). The Italian version of the OSIS is a reliable, valid, and reproducible outcome measure for clinical evaluation of patients affected by shoulder instability, which remains simple and user-friendly as the original version. Prospective cohort study, Level II. The availability of a validated translation of the OSIS will help surgeon to share their data on shoulder instability diagnostic and treatment in a more reproducible and comparable fashion.

The aim of this study is to describe a new surgical procedure to plicate the anterior bundle medial collateral ligament (aMCL) into its humeral footprint using a suture anchor, and to present the results of a preliminary clinical series. Eight patients with posttraumatic medial elbow pain and signs of medial elbow instability underwent aMCL plication with suture anchors and decompression of ulnar nerve. Arthroscopic evaluation permitted to define signs of minor medial elbow instability; 70°-scope was used to document from an intra-articular point of view of the aMCL status. The patients were then retrospectively evaluated with the Oxford Elbow Score (OES), Mayo Elbow Performance Score (MEPI) and single-assessment numeric evaluation (SANE) by an independent examiner. In all cases, the 70°-scope allowed direct visualization of the aMCL. Lateral subluxation of the coronoid process into the trochlea was observed in all patients. Postoperative median SANE was 50 [35–74.5] points; postoperative median OES was 17 [15.5–31.5] points; postoperative median MEPI was 65 [57.5–72.5] points. None of the patients reported further episodes of medial elbow instability or pain and all patients returned to normal daily activities. The 70°-scope arthroscopic evaluation of the joint allows a direct evaluation of the inner aMCL status. Lateral subluxation of the coronoid process into the trochlea was observed and can be considered a sign of minor medial elbow instability. Mini-open suture anchor aMCL plication is an original technique that enables an anatomic and minimally invasive ligament retension. The authors introduce a valid and safe treatment of posttraumatic medial elbow laxity.

Purpose The aims of this study were to measure the distance of the posterior interosseous nerve (PIN) from the radial head (RH) and its variations with forearm movements. Methods Five fresh frozen cadaver specimens were dissected under arthroscopy. An anterior capsulectomy extended to the entire lateral compartment was performed. The need of soft tissue dissection to isolate the nerve in the extracapsular space was recorded. The distance between the nerve and the anterior part of the RH was then measured with a graduated caliper inserted via the midlateral portal with the forearm in neutral position, full pronation, and full supination. Results The PIN was identifiable in all the specimens. In four cases, it was surrounded by a thick layer of adipose tissue, and further dissection was necessary to isolate it. Damage of the PIN during dissection occurred in one case, in which the proximal part of the nerve was accidentally cut. In three of the remaining cases, an increased distance was measured with the forearm in supination, as compared with neutral and full pronation position. Conclusion This anatomical study suggests that in most of the cases, the PIN does not lay just extracapular at the level of the radiocapitellar joint, but is surrounded by a thick layer of adipose tissue. Furthermore, its distance from the RH appears to increase with forearm supination. This position could increase the safe working space between RH and PIN. Clinical Relevance Knowledge of PIN position in relation to the anterior elbow capsule and its changes with forearm movements can help reduce the iatrogenic injuries during elbow arthroscopy.

The presence of intra-articular findings that may complement the extra-articular pathology in lateral epicondilytis has been suggested, and a role for minor instability of the elbow as part of the causative process of this disease has been postulated. This study was designed to describe two new clinical tests, aimed at detecting intra-articular pathology in patients affected by recalcitrant lateral epicondylitis and investigate their diagnostic performance. Ten patients suffering of atraumatic lateral elbow pain unresponsive to conservative treatment were considered in this study. Two clinical tests were developed and administrated prior to arthroscopy: Supination and Antero-Lateral pain Test (SALT); Posterior Elbow Pain by Palpation-Extension of the Radiocapitellar joint (PEPPER). Sensitivity, specificity, predictive values and accuracy of SALT and PEPPER as diagnostic tests for seven intra-articular findings were calculated. In 90% of the patients, at least one test was positive. All patients with signs of lateral ligamentous patholaxity or intra-articular abnormal findings had a positive response to at least one of the two tests. SALT proved to have a high sensitivity but a low specificity and is accurate in detecting the presence of intra-articular abnormal findings, especially synovitis. PEPPER test was sensible, specific and accurate in the detection of radial head chondropathy. Two new diagnostic tests (SALT and PEPPER) were specifically designed to evoke pain from intra-articular structures. These tests could be a valid support in the diagnostic algorithm of recalcitrant lateral elbow pain. Positive findings may be indicative of a minor instability of the lateral elbow condition. Diagnostic study, development of diagnostic criteria on basis of consecutive patients, level II.

Background The aim of this study was to find reliable anatomic landmarks of the normal acromioclavicular joint (ACJ) that could enable the precise evaluation of the horizontal displacement of the clavicle after dislocation. The hypothesis was that the anterior borders of the acromion and the clavicle are always aligned in intact ACJs. Materials and methods In 30 cadaveric specimens, the anterior and posterior borders of the ACJ's articular facets and the most prominent anterior and posterior bony landmarks of the acromion and the clavicle were identified. The anterior and posterior overhang of the acromion and the clavicle was measured in relation to the borders of the articular facets. Therefore, the possible anterior and posterior alignment of the ACJ was evaluated. Results Anteriorly, only 18 ACJs (60%) were aligned whereas 7 (24%) had major overhang of the acromion and 3 (10%) had major overhang of the clavicle. Similarly, 18 cases (60%) were posteriorly aligned, whereas 6 (20%) had major clavicular overhang and 4 (14%) had major overhang of the acromion. In 78% of these cases, the ACJ was aligned as well anteriorly as posteriorly ( P P = .032) or the clavicle ( P = .049), the better the posterior joint alignment. Conclusion Our hypothesis was not verified. The acromion and clavicle are not perfectly aligned in a significant number of specimens with intact ACJs (40% of cases). The most reliable landmarks remain their articular facets.

This chapter presents the technique and the results of arthroscopic plication of the radial component of the lateral collateral ligament (R-LCL). Elongation or partial articular-sided tears of the R-LCL may lead to a symptomatic minor instability of the lateral elbow (SMILE) and cause lateral elbow pain and disability. An all-arthroscopic technique to repair the R-LCL with a suture anchor was developed. The benefits of this all-arthroscopic procedure for surgical stabilization of the R-LCL include smaller incisions with less soft-tissue dissection, better visualization of the joint, easier accessibility for surgical instruments, and possibility of effective control lateral elbow patholaxity. The main steps of the operation are test of lateral elbow patholaxity, evaluation of the annular drive-through (ADT) sign, inspection of the radial side of the joint, insertion of a suture anchor through the anterolateral portal, shuttling of the suture anchor through the ligament, and verification of effective elimination of the annular drive-through sign. This technique of R-LCL plication ensures an anatomic repair.

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.

The engineering development and outcomes of distal humeral hemiarthroplasty (DHH) have gained increasing interest for the utilization of these implants in a new large horizon of clinical scenario. This chapter will focus on the spectrum of the surgical indications and the expected results of DHH.

Case A patient who had previously been diagnosed with fibrodysplasia ossificans progressiva was seen for hip pain and progressive soft tissue ossifications. Through a careful clinical examination, by which a subtype of brachydactyly was noted, the Albright hereditary osteodystrophy phenotype was recognized, and a new diagnosis of pseudopseudohypoparathyroidism was established. This paucisymptomatic condition often remains unidentified; however, its transmission can lead to more potentially serious diseases. Conclusions A careful diagnostic process, including physical examination, is essential. Even if advanced tests exist, small clinical findings can lead to the proper conclusion. In our case, a finger pointed us in the right direction.

Purpose: the purpose of this study is to describe a new arthroscopic technique for reduction and fixation of coronoid process fractures (CPFs) and report clinical and functional results in 4 patients after a 24-month follow-up. Methods: four patients underwent arthroscopic reduction and fixation of isolated CPFs (acute or non-unions, type I or type II according to the Regan-Morrey classification) performed using a new technique based on coronoid tunnelling and capsular plication. The patients were evaluated 6, 12 and 24 months after surgery, using the Disability of the Arm, Shoulder and Hand scale (DASH), the Mayo Elbow Performance Index (MEPI), and a visual analog scale (VAS); elbow range of motion (ROM) and joint stability were also evaluated and the rate of complications was reported. Results: all 4 patients completed the follow-up. At 6, 12 and 24 months, respectively, they recorded mean DASH scores of 22, 14 and 7, mean MEPI scores of 74, 82 and 94, and mean VAS scores of 4, 2 and 1. The mean ROM increased in all directions (at 6, 12 and 24 months, respectively: flexion: 112°, 125°, 144°; extension: 3°, 5°, 6°; pronation: 76°, 84°, 91°; supination: 78°, 82°, 86°). No signs of instability were observed and no complications were reported. Conclusions: the new all-arthroscopic coronoid tunnelling and capsular plication technique here proposed can restore elbow function, ROM and stability and allows anatomical reconstruction of the joint after type I or type II CPFs. if performed by an experienced arthroscopist, it is a valid alternative to open reduction and external fixation. Level of evidence: Level IV, retrospective case series.

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.

Background:Pseudoparalysis is defined as active forward flexion less than 90° with full passive motion. There is controversy about the ideal surgical management of a massive rotator cuff tear with pseudoparalysis.Purpose/Hypothesis:The purpose of this study was to prospectively analyze the ability to reverse pseudoparalysis with an arthroscopic rotator cuff repair (ARCR). The hypothesis was that in the absence of substantial glenohumeral arthritis, preoperative fatty infiltration of grade 3 or higher and an acromiohumeral interval (AHI) of less than 7 mm would not prevent reversal of pseudoparalysis with an ARCR.Study Design:Case series; Level of evidence, 4.Methods:A prospective multicenter study of ARCR performed for preoperative pseudoparalysis was conducted. The minimum follow-up was 1 year. The mean patient age was 63 years, and pseudoparalysis was present for a mean of 4.2 months preoperatively. Preoperative radiographic evaluation included plain film evaluation of the AHI and Hamada classification and MRI evaluation of fatty degeneration and rotator cuff retraction. Functional outcome was determined by the Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES) Shoulder Score, visual analog scale (VAS), and subjective shoulder value (SSV).Results:Of the 58 patients enrolled, 56 had at least 1 year of follow-up. Mean active forward flexion improved from 47° preoperatively to 159° postoperatively ( P < .001). Statistically significant improvements were seen in the SST (from 2.8 preoperatively to 10.1 postoperatively), SSV (from 28 to 83), ASES Shoulder Score (from 37 to 88), and VAS (from 5.7 to 1.1) ( P < .001). Pseudoparalysis was reversed in 53 of 56 patients (95%). There was no difference in the rate of reversal of pseudoparalysis between those patients with an AHI of less than 7 mm (88.2%) and those with an AHI of 7 mm or more (96.9%) ( P =.289). Pseudoparalysis was reversed in all 8 of the patients with fatty degeneration of grade 3 or higher in 1 or more of the rotator cuff muscles.Conclusion:ARCR can lead to reversal of preoperative pseudoparalysis in patients with minimal preoperative glenohumeral arthritis. ARCR is a viable first line of treatment for patients with pseudoparalysis in the absence of advanced glenohumeral arthritis.