Comprehensive Insights into Chondroblastoma Metastasis: Metastatic Patterns and Therapeutic Approaches.

Chondroblastoma metastasis, though rare, represents a clinically significant and notably important aspect of bone tumors. Understanding its epidemiological characteristics, pathological features, and treatment modalities, despite its infrequency, is imperative for comprehensive patient management. This review aims to elucidate the epidemiology, molecular mechanisms, diagnostic challenges, and therapeutic strategies associated with chondroblastoma metastasis. The patterns, prognostic factors, and treatment outcomes were explored through an analysis of case studies and clinical reports. Notably, we highlighted emerging therapeutic perspectives aimed at improving patient outcomes. To the best of our knowledge, there has been no previous review addressing these matters cumulatively, highlighting a significant gap in the existing scholarly literature. By shedding light on the nuances of chondroblastoma metastasis, this review contributes to the advancement of knowledge in this field and informs clinical decision-making for improved patient care.

Restoration of internal rotation after reverse shoulder arthroplasty may vary depending on etiology in patients younger than 60 ​years of age: a multicenter retrospective study.

BACKGROUND: Reverse shoulder arthroplasty (RSA) offers promising functional outcomes for young patients, yet challenges persist in restoring internal rotation (IR). This study aimed to assess the restoration of IR after RSA in patients younger than 60 years of age and analyze the factors affecting IR recovery. METHODS: A retrospective multicenter study was conducted, examining the functional outcome of patients who underwent RSA, with a minimum follow-up period of 2 years. Two subgroups of patients who underwent primary RSA were analyzed separately with respect to active internal rotation with the elbow at the side (AIR1): "difficult AIR1" and "easy AIR1." RESULTS: The study included 136 patients (overall series) with a mean age of 51.6 years. The overall series showed statistically significant improvement in active range of motion (RoM), pain, and Constant scores, especially with active IR (p â€‹< â€‹0.01). According to etiology, statistically significant improvement (p â€‹< â€‹0.05) in active IR was observed for fracture sequelae, primary osteoarthritis, and rheumatoid arthritis, whereas no statistically significant improvement in IR was observed for tumor, revision, and cuff-tear arthropathy (p â€‹> â€‹0.05). In subgroup analysis, patients with easy AIR1 displayed a statistically significant lower body mass index and better Constant score mobility, as well as improved motion in forward elevation and active IR (p â€‹< â€‹0.05). No statistically significant associations were found between improved IR and prosthetic design or subscapularis repair. Scapular notch, lysis of the graft, and teres minor atrophy were significantly associated with better active IR (p â€‹< â€‹0.05). CONCLUSION: RSA improves active RoM, pain, and functional outcomes in patients aged under 60. However, the degree of improvement in IR may vary depending on several factors and the underlying etiologies. These insights are crucial for patient selection and counseling, guiding RSA optimization efforts. LEVEL OF EVIDENCE: IV.

The Gritti-Stokes Amputation: Is It Still a Reliable Technique in the 21st Century? A Narrative Review.

Lower limb amputation is a common surgical procedure performed worldwide. Many individuals require amputation due to various circumstances, with amputations occurring above or below the knee. Surgeons rely on published research to determine the most appropriate technique based on intraoperative and postoperative outcomes. The Gritti-Stokes amputation (GSA) procedure, introduced in 1857, has shown positive results in terms of primary wound healing, reduced mortality rates during and after surgery, and accelerated healing and mobility. However, due to the need for highly trained surgeons and limitations in functional and cosmetic prosthesis fitting, concerns have been raised regarding its utility. Additionally, the procedure is underutilized in cases where it could potentially yield better results. This article provides a comprehensive review of the documented benefits of GSA, suitable candidate selection, limitations, various modifications, and a comparison with traditional approaches to lower limb amputation. The review is focused on evidence published in the last 100 years.

Better Constant Scores and Active Forward Elevation Using Deltopectoral Versus Anterosuperior Approach for Reverse Shoulder Arthroplasty: Matched Cohort Study.

Purpose: To determine, from a sizable cohort of reverse shoulder arthroplasty (RSA), whether the deltopectoral (DP) or anterosuperior (AS) approach grant better outcomes at a minimum follow-up of 24 months. Methods: The authors reviewed 743 RSAs in patients with primary osteoarthritis (OA) with or without rotator cuff lesions and secondary OA due to rotator cuff tears. The DP approach was used in 540 and the AS approach in 203. Pre- and post-operative constant scores (CSs) and shoulder range of motion were recorded. Results: Of the initial cohort of 743 shoulders, 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised; 540 shoulders were operated using DP approach (73%), of which 22 were revised (4.1%), while 203 were operated using the AS approach (27%), of which 11 were revised (5.4%). Propensity score matching resulted in two groups: 172 shoulders operated by DP approach, and 88 shoulders operated by AS approach. Comparing outcomes of the matched groups at 2 or more years also revealed that, compared to the AS approach, the DP approach resulted in significantly better post-operative CSs (67.3 ± 14.0° vs 60.8 ± 18.3, P = 0.017), active forward elevation (137° ± 27.4° vs 129° ± 29.8; P = 0.031). Conclusion: At 2 or more years following RSA, the DP approach granted significantly better CS (by 6.5 points) and active forward elevation (by 8°) compared to the AS approach. The differences observed are clinically relevant and must be considered to manage patient expectations following RSA and for selecting surgical approach depending on their functional needs. Level of evidence: III, comparative study.

Validation of mixed-reality surgical navigation for glenoid axis pin placement in shoulder arthroplasty using a cadaveric model.

BACKGROUND: Mixed reality may offer an alternative for computer-assisted navigation in shoulder arthroplasty. The purpose of this study was to determine the accuracy and precision of mixed-reality guidance for the placement of the glenoid axis pin in cadaver specimens. This step is essential for accurate glenoid placement in total shoulder arthroplasty. METHODS: Fourteen cadaveric shoulders underwent simulated shoulder replacement surgery by 7 experienced shoulder surgeons. The surgeons exposed the cadavers through a deltopectoral approach and then used mixed-reality surgical navigation to insert a guide pin in a preplanned position and trajectory in the glenoid. The mixed-reality system used the Microsoft Hololens 2 headset, navigation software, dedicated instruments with fiducial marker cubes, and a securing pin. Computed tomography scans obtained before and after the procedure were used to plan the surgeries and determine the difference between the planned and executed values for the entry point, version, and inclination. One specimen had to be discarded from the analysis because the guide pin was removed accidentally before obtaining the postprocedure computed tomography scan. RESULTS: Regarding the navigated entry point on the glenoid, the mean difference between planned and executed values was 1.7 ± 0.8 mm; this difference was 1.2 ± 0.6 mm in the superior-inferior direction and 0.9 ± 0.8 mm in the anterior-posterior direction. The maximum deviation from the entry point for all 13 specimens analyzed was 3.1 mm. Regarding version, the mean difference between planned and executed version values was 1.6° ± 1.2°, with a maximum deviation in version for all 13 specimens of 4.1°. Regarding inclination, the mean angular difference was 1.7° ± 1.5°, with a maximum deviation in inclination of 5°. CONCLUSIONS: The mixed-reality navigation system used in this study allowed surgeons to insert the glenoid guide pin on average within 2 mm from the planned entry point and within 2° of version and inclination. The navigated values did not exceed 3 mm or 5°, respectively, for any of the specimens analyzed. This approach may help surgeons more accurately place the definitive glenoid component.

Efficacy of Percutaneous Treatment of Primary Aneurysmal Bone Cysts (ABCs): A Systematic Review and Meta-Analysis.

BACKGROUND: Percutaneous treatment for primary aneurysmal bone cysts (ABCs) has been widely accepted. The study aimed to evaluate the efficacy of various sclerotherapy agents on patients with primary ABCs. METHODS: A meta-analysis of relevant studies. A systematic search was conducted on five databases, resulting in the inclusion of 25 studies with different percutaneous agents. RESULTS: A total of 729 patients with primary ABCs were included. Patients were administered with Ethibloc, doxycycline, embolization, alcohol, polidocanol, and calcitonin with methylprednisolone, respectively. Overall, 542 (74.3%) patients with ABCs had complete healing, 120 (16.4%) had partial healing, 44 (6%) had no-ossification or failure, and 26 (3.5%) had a recurrence. However, there was a total of 45 (6.1%) patients who had surgical curettage after sclerotherapy. Among the sclerotherapy agents, doxycycline showed highly effective results with minimal complications and recurrence, but it required multiple injections per patient. Ethibloc and embolization also proved to be highly effective with fewer injections required but had a higher rate of complications. Absolute alcohol, polidocanol, and calcitonin with methylprednisolone had similar efficacity and favorable success with fewer complications and fewer injections. CONCLUSION: Percutaneous treatment showed promising results in treating primary ABCs. However, more robust research is needed to establish the best approach for sclerotherapy in clinical practice and to address the limitations of the current literature.

Infected Shoulder Arthroplasty in Patients Younger than 60 Years: Results of a Multicenter Study.

Background: Periprosthetic joint infection (PJI) after shoulder arthroplasty remains a significant complication. This study aimed to explore the epidemiology and risk factors of shoulder PJI in patients aged 60 and younger, analyze treatment options, and evaluate outcomes after 1-year follow-up. Methods: In this retrospective multicentric observational study, data from 1404 shoulders in patients under 60 who underwent primary shoulder arthroplasty were analyzed. Patients with PJI and at least 1-year follow-up after infection treatment were included. Results: The study identified 55 shoulders with PJI, resulting in a 2.35% infection rate after primary shoulder arthroplasty in the young population. Male gender and reverse shoulder arthroplasty were risk factors for infection, while previous surgeries did not significantly contribute. The most common causative agents were Cutibacterium acnes and Staphylococcus epidermidis. Open washout had a 52.9% success rate for acute infections, while one-stage and two-stage revisions achieved infection control rates of 91.3% and 85.7%, respectively. Resection arthroplasty had an 81.8% success rate but poorer functional outcomes. Conclusions: PJI following shoulder arthroplasty in young patients is a significant concern. Preoperative planning should be carefully considered to minimize infection risk. Treatment options such as open washout and one-stage and two-stage revisions offer effective infection control and improved functional outcomes. Resection arthroplasty should be reserved for complex cases where reimplantation is not a viable option.

Tenotomy or tenodesis versus conservation of the long head of the biceps tendon in the repair of isolated supraspinatus tears: A systematic review of the literature.

BACKGROUND: Few studies have directly compared the outcomes of rotator cuff repair (RCR) with or without concomitant LHBT tenotomy or tenodesis. The aim of this literature review was to assess: (i) whether an adjuvant procedure on the LHBT at the time of RCR gives better functional results than RCR alone; and (ii) whether reoperation rates are higher after RCR alone or RCR+tenotomy or tenodesis. METHODS: A literature search was carried out on PubMed, MEDLINE, Embase, Web of Science and the Cochrane database for papers published in English or French between 1st January, 2010, and 31st December, 2021. Included studies compared the results of RCR alone with RCR+concomitant tenotomy or tenodesis in patients with tears of the supraspinatus tendon or rotator cuff. ARTICLES: A total of 626 articles were identified in the literature search and 168 were retained for more detailed examination. Forty-seven articles were read in their entirety and nine articles comparing RCR with or without concomitant tenotomy or tenodesis of the LHBT were retained for the analysis. RESULTS: Nine articles comparing the results of RCR alone versus RCR+LHBT tenotomy or tenodesis were reviewed. The majority of patients were more than 50 years old and male. The rate of lesions to the LHBT in the studies included ranged from 26.8-60.2%. Eight of the nine studies compared the functional results of RCR alone versus RCR+tenotomy or tenodesis, with six reporting no significant difference, one reporting better outcomes after concomitant biceps surgery and one reporting worse outcomes after a biceps procedure. DISCUSSION: This review did not provide a strong answer to our questions, owing to the heterogenicity of clinical evaluation and low level of evidence of the studies. However, it appears that in the absence of biceps pathology or in the presence of small lesions, the LHBT could be preserved. The rate of revision did not seem to be higher and cuff healing lower in this situation. Therefore, further randomized studies are required to identify the role of concomitant procedure of the biceps in case of small isolated supraspinatus repair. LEVEL OF EVIDENCE: III; systematic review.

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 2: The IA-RTRHO model - a decision-making aid for long head of the biceps diagnoses in small rotator cuff tears.

INTRODUCTION: The possible applications of artificial intelligence (AI) in orthopedic surgery are promising. Deep learning can be utilized in arthroscopic surgery due to the video signal used by computer vision. The intraoperative management of the long head of biceps (LHB) tendon is the subject of a long-standing controversy. The main objective of this study was to model a diagnostic AI capable of determining the healthy or pathological state of the LHB on arthroscopic images. The secondary objective was to create a second diagnostic AI model based on arthroscopic images and the medical, clinical and imaging data of each patient, to determine the healthy or pathological state of the LHB. HYPOTHESIS: The hypothesis of this study was that it was possible to construct an AI model from operative arthroscopic images to aid in the diagnosis of the healthy or pathological state of the LHB, and its analysis would be superior to a human analysis. MATERIALS AND METHODS: Prospective clinical and imaging data from 199 patients were collected and associated with images from a validated protocoled arthroscopic video analysis, called "ground truth", made by the operating surgeon. A model based on a convolutional neural network (CNN) modeled via transfer learning on the Inception V3 model was built for the analysis of arthroscopic images. This model was then coupled to MultiLayer Perceptron (MLP), integrating clinical and imaging data. Each model was trained and tested using supervised learning. RESULTS: The accuracy of the CNN in diagnosing the healthy or pathological state of the LHB was 93.7% in learning and 80.66% in generalization. Coupled with the clinical data of each patient, the accuracy of the model assembling the CNN and MLP were respectively 77% and 58% in learning and in generalization. CONCLUSION: The AI model built from a CNN manages to determine the healthy or pathological state of the LHB with an accuracy rate of 80.66%. An increase in input data to limit overfitting, and the automation of the detection phase by a Mask-R-CNN are ways of improving the model. This study is the first to assess the ability of an AI to analyze arthroscopic images, and its results need to be confirmed by further studies on this subject. LEVEL OF EVIDENCE: III Diagnostic study.

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.

The Real Post-Operative Range of Motion Differs from the Virtual Pre-Operative Planned Range of Motion in Reverse Shoulder Arthroplasty.

INTRODUCTION: The purpose of this study was to analyze the real range of motion (RoM) measured in patients operated on for reverse shoulder arthroplasty (RSA) and compare it to the virtual RoM provided by the preoperative planning software. HYPOTHESIS: There was a difference between virtual and real RoM, which can be explained by different factors, specifically the scapula-thoracic (ST) joint. METHODS: Twenty patients with RSA were assessed at a minimum follow-up of 18 months. Passive RoM in forward elevation abduction, without and with manually locking the ST joint, and in external rotation with arm at side were recorded. The humerus, scapula, and implants were manually segmented on post-operative CTs. Post-operative bony structures were registered to preoperative bony elements. From this registration, a post-operative plan corresponding to the real post-operative implant positioning was generated and the corresponding virtual RoM analysis was recorded. On the post-operative anteroposterior X-rays and 2D-CT coronal planning view, the glenoid horizontal line angle (GH), the metaphyseal horizontal line angle (MH), and the gleno-metaphyseal angle (GMA) were measured to assess the extrinsic glenoid inclination, as well as the relative position of the humeral and glenoid components. RESULTS: There were some significant differences between virtual and post-operative passive abduction and forward elevation, with (55° and 50°, p < 0.0001) or without ST joint participation (15° and 27°, p < 0.002). For external rotation with arm at side, there was no significant difference between planning (24° ± 26°) and post-operative clinical observation (19° ± 12°) (p = 0.38). For the angle measurements, the GMA was significantly higher (42.8° ± 15.2° vs. 29.1°± 18.2°, p < 0.0001), and the GH angle, significantly lower on the virtual planning (85.2° ± 8.8° vs. 99.5° ± 12.5°, p < 0.0001), while the MH was not different (p = 0.33). CONCLUSIONS: The virtual RoM given by the planning software used in this study differs from the real post-operative passive RoM, except for external rotation. This can be explained by the lack of ST joint and soft tissues simulation. However, in focusing on the virtual GH participation, the simulation looks informative. Some modifications between the glenoid and humerus starting positions before running the motion analysis could be provided for making it more realistic and predictive of the RSA functional results. LEVEL OF EVIDENCE: III.

Preoperative Planning for Reverse Shoulder Arthroplasty: Does the Clinical Range of Motion Match the Planned 3D Humeral Displacement?

INTRODUCTION: The functional outcome after reverse shoulder arthroplasty (RSA) is closely linked to how much the humerus shifts because of the implants. While two-dimensional (2D) angle measurements have been used to capture this shift, it can be measured in three dimensions (3D) as the arm change position (ACP). In a previous study, the ACP was measured using 3D preoperative planning software with the passive virtual shoulder range of motion obtained after RSA. The main objective of this study was to evaluate the relationship between the ACP and the actual active shoulder range of motion measured after RSA. The hypothesis was that the ACP and the active clinical range of motion are related such that the ACP is a reliable parameter to guide the preoperative planning of an RSA. The secondary objective was to assess the relationship between 2D and 3D humeral displacement measurements. MATERIALS AND METHODS: This prospective observational study enrolled 12 patients who underwent RSA and had a minimum follow-up of 2 years. The active range of motion in shoulder flexion, abduction, and internal and external rotation was measured. At the same time, ACP measurements were taken from a reconstructed postoperative CT scan, in addition to the radiographic measurements of humeral lateralization and distalization angles on AP views in neutral rotation. RESULTS: The mean humeral distalization induced by RSA was 33.3 mm (±3.8 mm). A non-statistically significant increase in shoulder flexion was observed for humeral distalization beyond 38 mm (R2 = 0.29, p = 0.07). This "threshold" effect of humeral distalization was also observed for the gains in abduction, as well as internal and external rotations, which seemed better with less than 38 mm or even 35 mm distalization. No statistical correlation was found between the 3D ACP measurements and 2D angle measurements. CONCLUSION: Excessive humeral distalization seems to be detrimental to joint mobility, especially shoulder flexion. Humeral lateralization and humeral anteriorization measured using the ACP seem to promote better shoulder range of motion, with no threshold effect. These findings could be evidence of tension in the soft tissues around the shoulder joint, which should be taken into consideration during preoperative planning.

Inter- and intra-observer agreement in arthroscopic assessment of the long head of the biceps.

INTRODUCTION: Long head of the biceps (LHB) pathology is frequent but can be difficult to diagnose. Arthroscopy is the current diagnostic gold-standard. The aim of the present study was to assess inter- and intra-observer agreement in arthroscopic analysis of the LHB. HYPOTHESIS: Agreement in arthroscopic analysis of the LHB is good in the particular case of small rotator cuff tears. MATERIAL AND METHODS: This prospective study included 49 patients operated on between November 1 and November 30, 2017. Seven surgeons were asked to record videos of arthroscopic LHB analysis for Patte-1 small supraspinatus tendon tears. One junior and 2 senior surgeons analyzed the videos independently, studying macroscopic intrinsic and extrinsic LHB aspect. Inter-observer agreement, and intra-observer agreement for the junior surgeon, were analyzed. RESULTS: Inter-observer agreement between the surgeons and intra-observer agreement for the junior surgeon were slight in describing the pathologic aspect of the LHB: respectively, κ=0.254, p<0.038; and κ=0.319, p<0.0019. DISCUSSION: Isolated arthroscopic LHB assessment without clinical or paraclinical input or precise surgical exploration protocol showed slight inter-observer agreement. Analysis and interpretation of LHB aspect should in practice be based on combined clinical, paraclinical and arthroscopic data. LEVEL OF EVIDENCE: III.

Anatomical plane and transverse axis of the scapula: Reliability of manual positioning of the anatomical landmarks.

Background: The aim of our study was to evaluate the accuracy of manual determination of the three key points defining the anatomical plane of the scapula, which conditions the reliability of planning software programs based on manual method. Method: We included 82 scapula computed tomography scans (56 pathologic and 26 normal glenoid), excluding truncation and major three-dimensional artifact. Four observers independently picked the three key points for each case. Inter- and intra-observer agreement was calculated for each point, using the intraclass correlation method. The mean error (mm) between the observers was calculated as the diameter of the smallest sphere including the four chosen positions. Results: Lower inter-observer agreement was found for the trigonum superoinferior position and for the glenoid center anteroposterior position. The mean positioning error between the four observers was 6.9 mm for the trigonum point, and error greater than 10 mm was recorded in 25% of the cases. The mean positioning error was 3.5 mm for the glenoid center in altered glenoid, compared to 1.8 mm for normal glenoid. Discussion: Manual determination of an anatomical plane of the scapula suffers from inaccuracy especially due to the variability in trigonum picking, and in a lesser extent, to the variability of glenoid center picking in altered glenoid.

Glenoid Inclination: Choosing the Transverse Axis Is Critical-A 3D Automated versus Manually Measured Study.

The aim of this study was to evaluate the variation in measured glenoid inclination measurements between each of the most used methods for measuring the scapular transverse axis with computed tomography (CT) scans, and to investigate the underlying causes that explain the differences. METHODS: The glenoid center, trigonum and supraspinatus fossa were identified manually by four expert shoulder surgeons on 82 scapulae CT-scans. The transverse axis was generated either from the identified landmarks (Glenoid-Trigonum line (GT-line), Best-Fit Line Fossa (BFLF)) or by an automatic software (Y-axis). An assessment of the interobserver reliability was performed. We compared the measured glenoid inclination when modifying the transverse axis to assess its impact. RESULTS: Glenoid inclination remained stable between 6.3 and 8.5°. The variations occurred significantly when changing the method that determined the transverse axis with a mean biase from -1.7 (BFLF vs. Y-axis) to 0.6 (BFLF vs. GT-line). The Y-axis method showed higher stability to the inclination variation (p = 0.030). 9% of cases presented more than 5° of discrepancies between the methods. The manual methods presented a lower ICC (BFLF = 0.96, GT-line = 0.87) with the widest dispersion. CONCLUSION: Methods that determine the scapular transverse axis could have a critical impact on the measurement of the glenoid inclination. Despite an overall good concordance, around 10% of cases may provide high discrepancies (≥5°) between the methods with a possible impact on surgeon clinical choice. Trigonum should be used with caution as its anatomy is highly variable and more than two single points provide a better interrater concordance. The Y-axis is the most stable referential for the glenoid inclination.

Management of normal long head of the biceps tendon in isolated grade-1 supraspinatus tear: Research protocol for a multicenter prospective single-blind randomized study.

BACKGROUND: The long head of the biceps (LHB) tendon is a common locus of pain in rotator cuff tear and of residual pain after tendon repair. Therefore, systematic LHB tenotomy, with or without tenodesis, is usually recommended. However, the recent literature suggests that long-term functional results of supraspinatus tendon repair are comparable between conservation of a normal biceps and tenotomy. The study objective is to compare functional results between sectioning and sparing a normal LHB in treating isolated grade-1 supraspinatus tendon tear. The study hypothesis is that sparing the normal LHB is clinically preferable to sectioning in the particular case of distal supraspinatus tear. METHODS AND ANALYSIS: A French nationwide prospective single-blind randomized clinical study will include 194 patients undergoing arthroscopic repair of grade-1 supraspinatus tear with normal LHB. They will be randomized to 2 parallel groups: LHB sparing and sectioning. The main endpoint is Constant-Murley score, and secondary endpoints comprise ASES and SSV scores, clinical assessment of the biceps, pain on VAS, ultrasound assessment of cuff repair healing and conserved LHBs, impact on return to work and sport, pathologic assessment of sectioned LHBs, and analysis of risk factors for cuff repair failure. ETHICAL APPROVAL AND PUBLICATION: The protocol has been approved by the data protection committee (art.L.1122-1) and meets the criteria of the Declaration of Helsinki and of the SPIRIT statement defining standard protocol items for clinical trials. Results will be published in a peer-reviewed journal. LEVEL OF EVIDENCE: not applicable.

Can surgeons optimize range of motion and reduce scapulohumeral impingements in reverse shoulder arthroplasty? A computational study.

Background: Early glenohumeral impingement leads to poor range of motion and notching in reverse shoulder arthroplasty. The aim was to find from planning software which implant configuration provides the best motions in reverse shoulder arthroplasty. Patients and Methods: Reverse shoulder arthroplasty planning (Glenosys) was made in 31 patients (12 men, 19 women, 76 ± 6 yo) and impingements were analyzed. Inlay (155°-inclined) and Onlay (145°-inclined) humeral designs were tested. Four configurations were tested for each shoulder: "INLAY": non-lateralized glenoid-inlay humerus, "BIO-INLAY": lateralized glenoid (BIO-RSA)-inlay humerus, "ONLAY": non-lateralized glenoid-onlay humerus, and "BIO-ONLAY": lateralized (BIO-RSA) glenoid-onlay humerus. Results: BIO-ONLAY and BIO-INLAY groups presented a significantly better result in all tested motion (p < 0.001 for all tests). BIO-ONLAY allowed a significantly better external rotation, extension and adduction than BIO-INLAY with decreased impingements with the pilar. BIO-INLAY presented a significantly better abduction. In abduction, an abutment of the greater tuberosity against the acromion was associated with a lower range of motion (p < 0.0001) and did not depend on the lateralization. Conclusion: Glenoid lateralization delays the glenohumeral impingement in reverse shoulder arthroplasty and gives the best rotations, adduction and extension when associated with neutral inclination and humeral 145° inclination. Greater tuberosity abutment has to be avoided in abduction and the Inlay design provides the best abduction.

Mechanical behavior of hybrid glenoid components compared to all-PE components: a finite element analysis.

PURPOSE: The purpose of this finite element study was to compare bone and cement stresses and implant micromotions among all-polyethylene (PE) and hybrid glenoid components. The hypothesis was that, compared to all-PE components, hybrid components yield lower bone and cement stresses with smaller micromotions. METHODS: Implant micromotions and cement and bone stresses were compared among 4 all PE (U-PG, U-KG, A-KG, I-KG) and 2 hybrid (E-hCG, I-hPG) virtually implanted glenoid components. Glenohumeral joint reaction forces were applied at five loading regions (central, anterior, posterior, superior and inferior). Implant failure was assumed if glenoid micromotion exceeded 75 µm or cement stresses exceeded 4 MPa. The critical cement volume (CCV) was based on the percentage of cement volume that exceeded 4 MPa. Results were pooled and summarized in boxplots, and differences evaluated using pairwise Wilcoxon Rank Sum tests. RESULTS: Differences in cement stress were found only between the I-hPG hybrid component (2.9 ± 1.0 MPa) and all-PE keeled-components (U-KG: 3.8 ± 0.9 MPa, p = 0.017; A-KG: 3.6 ± 0.5 MPa, p = 0.014; I-KG: 3.6 ± 0.6 MPa, p = 0.040). There were no differences in cortical and trabecular bone stresses among glenoid components. The E-hCG hybrid component exceeded micromotions of 75 µm in 2 patients. There were no differences in %CCV among glenoid components. CONCLUSIONS: Finite element analyses reveal that compared to all-PE glenoid components, hybrid components yield similar average stresses within bone and cement. Finally, risk of fatigue failure of the cement mantle is equal for hybrid and all-PE components, as no difference in %CCV was observed. LEVEL OF EVIDENCE: IV, in-silico.