Methods of analyzing the long head of the biceps tendon in the management of distal supraspinatus tendon ruptures. Part 2: The role and validation of an arthroscopic exploration protocol of the long head of the biceps tendon.

INTRODUCTION: Inter-observer arthroscopic assessments of the Long head of the Biceps tendon (LHB) injuries, in the absence of predefined instructions, are poorly reproducible. There are several types of LHB injuries, of varying severity, which can make its intraoperative analysis subjective. HYPOTHESIS: The application of a precise arthroscopic exploration protocol, particularly dynamic, associated with an equally precise analysis of the possible tendon lesions, intrinsic or extrinsic, makes it possible to obtain a reproducible analysis of the lesions of the LHB and aid decision-making around its conservation or its resection, in distal supraspinatus tendon ruptures. MATERIAL AND METHODS: This was a prospective, multicenter study including 371 patients with a stage 1 rupture of the supraspinatus tendon, in accordance with the Patte classification. An exploration protocol with intraoperative video recording of the articular portion of the biceps was systematically performed by the operators. It included static intra-articular and extra-articular observation of the LHB, as well as a dynamic intra-articular hook test with mobilization in internal and external rotation, and in anterior elevation. An analysis of the lesion status of the LHB was then made by the principal operator (Op), after defining the various possible lesions: intrinsic or extrinsic. This initial diagnostic assessment was then compared with the analysis made by two independent observers (Obs1, Obs2) based on a replay of the recorded videos. The reliability of agreement was then measured using Cohen's Kappa coefficient (K) and Fleiss' kappa. RESULTS: Two hundred and fifty-seven videos were analyzable. The level of agreement between the two independent observers was strong (K=0.63) for applying the diagnosis of a healthy or pathological biceps. The agreement between the independent observers and the operator was weaker (respectively K Op-Obs1=0.51 - moderate and K Op-Obs2=0.39 - poor). CONCLUSION: The application of a precise protocol for the exploration of the LHB, associated with a previously defined lesion classification, makes it possible to obtain a high rate of agreement for the arthroscopic diagnostic analysis of the LHB. However, arthroscopy cannot be used as the only criterion for deciding which procedure to perform on the LHB. Other clinical and para-clinical factors must be taken into consideration. LEVEL OF EVIDENCE: III; prospective inter-observer series.

Methods to analyse the long head of the biceps in the management of distal ruptures of the supraspinatus tendon. Part 1: the concept of the "biceps box": dynamic rotator interval approach. Incidence of lesions of the long head of the biceps tendon.

INTRODUCTION: The area encompassing the long head of the biceps (LHB) can be represented as a rectangular parallelepiped. This geometric view can be likened to a box, the "biceps box", where the sides are the extrinsic structures and the LHB is the intrinsic structure. Since these structures are mobile in relation to each other, a dynamic "biceps box" model can modify assessments of the LHB, in its healthy or pathological state, and make the therapeutic approach to treating LHB lesions less arbitrary. MATERIAL AND METHOD: In order to describe the different sides of the "biceps box", and to understand their possible physiological and pathological consequences, a literature review using PRISMA methodology was used. RESULTS: The supraspinatus (SSP) has expansions on its anterior aspect that project anteriorly and cross the coracohumeral ligament (CHL). The most functionally important expansion is the fasciculus obliquus, which extends perpendicular to the axis of the tendon fibers of the SSP, divides the CHL into a deep and a superficial layer, and terminates on the superficial aspect of the subscapularis. The humeral insertion of the SSP may be binary, making a bridge over the LHB, with a posterior branch inserting on the greater tuberosity and an anterior branch on the lesser tuberosity. The superior glenohumeral ligament (SGHL) has a twisted course, downward and forward, and ends at the proximal opening of the bicipital groove with a flap on which the LHB rests. The bicipital pulley is not an independent structure but an arciform structure resulting from the fusion of several tissues. DISCUSSION: The presence of structures linked together by common expansions in the 3 planes of space validates the relevance of a "biceps box" as a functional geometric model. The structure that acts as a crossroads through which all expansions pass is the CHL. An extrinsic SSP lesion can be compensated for by other "biceps box" structures, whereas an extrinsic SGHL lesion rarely exists without the presence of an intrinsic LHB lesion. The CHL constitutes a connective tissue crossed by a vasculonervous pedicle from the lateral pectoral nerve, which may explain some anterior shoulder pain attributed to the biceps. CONCLUSION: The LHB can be likened to an intrinsic structure contained in a box whose sides are made up of different interconnected stabilizing structures defining the extrinsic structures. The concept of a dynamic "biceps box" allows LHB lesions to be accurately classified, separating extrinsic and intrinsic lesions, and thus potentially modifying therapeutic approaches to the LHB. LEVEL OF EVIDENCE: IV; systematic review.

Can artificial intelligence help decision-making in arthroscopy? Part 1: Use of a standardized analysis protocol improves inter-observer agreement of arthroscopic diagnostic assessments of the long head of biceps tendon in small rotator cuff tears.

INTRODUCTION: Injuries of the long head of biceps (LHB) tendon are common but difficult to diagnose clinically or using imaging. Arthroscopy is the preferred means of diagnostic assessment of the LHB, but it often proves challenging. Its reliability and reproducibility have not yet been assessed. Artificial intelligence (AI) could assist in the arthroscopic analysis of the LHB. The main objective of this study was to evaluate the inter-observer agreement for the specific LHB assessment, according to an analysis protocol based on images of interest. The secondary objective was to define a video database, called "ground truth", intended to create and train AI for the LHB assessment. HYPOTHESIS: The hypothesis was that the inter-observer agreement analysis, on standardized images, was strong enough to allow the "ground truth" videos to be used as an input database for an AI solution to be used in making arthroscopic LHB diagnoses. MATERIALS AND METHOD: One hundred and ninety-nine sets of standardized arthroscopic images of LHB exploration were evaluated by 3 independent observers. Each had to characterize the healthy or pathological state of the tendon, specifying the type of lesion: partial tear, hourglass hypertrophy, instability, fissure, superior labral anterior posterior lesion (SLAP 2), chondral print and pathological pulley without instability. Inter-observer agreement levels were measured using Cohen's Kappa (K) coefficient and Kappa Accuracy. RESULTS: The strength of agreement was moderate to strong according to the observers (Kappa 0.54 to 0.7 and KappaAcc from 86 to 92%), when determining the healthy or pathological state of the LHB. When the tendon was pathological, the strength of agreement was moderate to strong when it came to a partial tear (Kappa 0.49 to 0.71 and KappaAcc from 85 to 92%), fissure (Kappa -0.5 to 0.7 and KappaAcc from 36 to 93%) or a SLAP tear (0.54 to 0.88 and KappaAcc from 90 to 97%). It was low for unstable lesion (Kappa 0.04 to 0.25 and KappaAcc from 36 to 88%). CONCLUSION: The analysis of the LHB, from arthroscopic images, had a high level of agreement for the diagnosis of its healthy or pathological nature. However, the agreement rate decreased for the diagnosis of rare or dynamic tendon lesions. Thus, AI engineered from human analysis would have the same difficulties if it was limited only to an arthroscopic analysis. The integration of clinical and paraclinical data is necessary to improve the arthroscopic diagnosis of LHB injuries. It also seems to be an essential prerequisite for making a so-called "ground truth" database for building a high-performance AI solution. LEVEL OF EVIDENCE: III; inter-observer prospective series.