What information does the surgeon need before using software to plan a total shoulder arthroplasty? An international perspective.

Shoulder arthroplasty is a surgical procedure that is increasingly being used to treat patients with shoulder joint disorders, such as osteoarthritis and rotator cuff tears. Preoperative planning and the accurate transfer of this plan to the surgical procedure are critical for the success of the surgery. Three-dimensional (3D) preoperative planning software that assists with arthroplasty requires some basic surgical planning steps.

Which is the optimal treatment and the most significant prognostic factor for reverse shoulder arthroplasty in case of PHAROS 2 humeral bone loss? A proportional meta-analysis of nononcologic patients.

Background: Reverse total shoulder arthroplasty (rTSA) for proximal humerus bone loss is linked with increased risks of complications and reoperation. This study aimed to compare the complication and reoperation rates between patients with unaddressed humeral defect (control group [CG]) and those receiving proximal humerus allograft prosthesis composite (APC) or mega-prosthesis (MP) (study group [SG]).

Methods: Systematic searches were conducted in MEDLINE/PubMed, Web of Science, and Embase to find studies on rTSA outcomes in proximal humerus bone loss cases.

All-Arthroscopic Inferior Glenohumeral Ligament Reconstruction With Gracilis Tendon Graft Can Successfully Restore Stability and Function in Predominantly Inferior and Multidirectional Instability Patients With Hyperlaxity.

Purpose: To report the early clinical and radiographic outcomes of an arthroscopic technique to reconstruct the inferior glenohumeral ligament (IGHL) to stabilize the glenohumeral joint in patients with predominantly inferior and multidirectional instability and hyperlaxity.

Methods: Between October 2019 and March 2023, patients with unidirectional (inferior) or multidirectional instability with hyperlaxity, as assessed by a positive Gagey hyperabduction test with instability severity index score >3, IGHL lesions on cross-sectional imaging (magnetic resonance imaging or magnetic resonance angiography) or on arthroscopy, without glenoid bone loss, and with a minimum 12-month follow-up, were enrolled. All patients had symptomatic instability, a positive Gagey hyperabduction test (>105°) on clinical examination, and unsuccessful physical therapy.

Advancing musculoskeletal shoulder modeling: reflecting glenohumeral translation with bony, ligamentous, and muscular stability constraints.

Introduction: Glenohumeral (GH) stability is a delicate interplay between bony congruence, muscle contraction, and ligamentous or capsular stability that can be disrupted by pathologies such as rotator cuff (RC) tears. We aimed to develop an advanced musculoskeletal shoulder model that incorporates subject-specific GH joint contact, active and passive muscle stability, and mechanical properties of ligaments to calculate GH translation using force-dependent kinematics (FDK). We hypothesized that inferior-superior GH translation computed using this model are consistent with GH translation measured by dynamic uniplanar fluoroscopy in healthy shoulders and in shoulders with partial or full RC tears, and that muscle and joint forces computed using the FDK shoulder model are higher than those of the default shoulder model.

Structural alterations during fracture healing lead to void spaces developing in surrounding bone microarchitecture.

Distal radius fractures are among the most common fracture sites, with a high incidence across all age groups. High-resolution peripheral quantitative computed tomography (HR-pQCT) has enabled assessment of bone microarchitecture in vivo at the distal radius, providing new insights into the healing process. However, we have observed structural bone loss that is not captured by standard analysis.

Deep learning algorithms enable MRI-based scapular morphology analysis with values comparable to CT-based assessments.

Scapular morphological attributes show promise as prognostic indicators of retear following rotator cuff repair. Current evaluation techniques using single-slice magnetic-resonance imaging (MRI) are, however, prone to error, while more accurate computed tomography (CT)-based three-dimensional techniques, are limited by cost and radiation exposure. In this study we propose deep learning-based methods that enable automatic scapular morphological analysis from diagnostic MRI despite the anisotropic resolution and reduced field of view, compared to CT.

Baseline characteristics and 2-year functional outcome data of patients undergoing an arthroscopic rotator cuff repair in Switzerland, results of the ARCR_Pred study.

The ARCR_Pred study was initiated to document and predict the safety and effectiveness of arthroscopic rotator cuff repair (ARCR) in a representative Swiss patient cohort. In the present manuscript, we aimed to describe the overall and baseline characteristics of the study, report on functional outcome data and explore case-mix adjustment and differences between public and private hospitals. Between June 2020 and November 2021, primary ARCR patients were prospectively enrolled in a multicenter cohort across 18 Swiss and one German orthopedic center.

Biomechanical evaluation of physical examination tests for rotator cuff tears: a computer simulation study.

Background: Numerous physical diagnostic shoulder tests have been established to determine the presence of rotator cuff tears and to identify the affected muscles. However, reported sensitivities and specificities of these tests vary strongly. The aim of this study was to identify diagnostic postures that are biomechanically most sensitive in identifying rotator cuff lesions and compensation mechanisms.

Automatic 3-dimensional analysis of posterosuperior full-thickness rotator cuff tear size on magnetic resonance imaging.

Background: Tear size and shape are known to prognosticate the efficacy of surgical rotator cuff (RC) repair; however, current manual measurements on magnetic resonance images (MRIs) exhibit high interobserver variabilities and exclude 3-dimensional (3D) morphologic information. This study aimed to develop algorithms for automatic 3D analyses of posterosuperior full-thickness RC tear to enable efficient and precise tear evaluation and 3D tear visualization.

Methods: A deep-learning network for automatic segmentation of the tear region in coronal and sagittal multicenter MRI was trained with manually segmented (consensus of 3 experts) proton density- and T2-weighted MRI of shoulders with full-thickness posterosuperior tears (n = 200).

Scapular morphology is associated with certain patterns of glenohumeral osteoarthritis but not with full-thickness rotator cuff tears.

Background: The role of anatomic factors in rotator cuff (RC) pathology or in the development of shoulder osteoarthritis (OA) is not yet well understood or recognized. While 2-dimensional imaging and measurements are easy to capture and interpret, three-dimensional (3D) methods provide a more thorough description and analysis of the scapula's complex shape. The purpose of this study is to investigate whether scapular anatomy is associated with RC tears or glenohumeral OA using 3D statistical shape modelling.

Navigated augmented reality through a head-mounted display leads to low deviation between planned, intra- and postoperative parameters during glenoid component placement of reverse shoulder arthroplasty: a proof-of-concept case series.

Background: Navigated augmented reality (AR) through a head-mounted display (HMD) has led to accurate glenoid component placement in reverse shoulder arthroplasty (RSA) in an in-vitro setting. The purpose of this study is to evaluate the deviation between planned, intraoperative, and postoperative inclination, retroversion, entry point, and depth of the glenoid component placement during RSA, assisted by navigated AR through an HMD, in a surgical setting.

Methods: A prospective, multicenter study was conducted.

Paget-Schroetter Syndrome in a Patient With Posterior Shoulder Subluxation: A Case Report.

Paget-Schroetter syndrome describes a primary thrombosis of the subclavian vein induced by effort. In most cases, the clinical presentation includes painful swelling, discoloration, and visible collateral circulation in the arm. Paget-Schroetter syndrome is treated with anticoagulation, rest, and physical therapy.

Effect of patient-specific scapular morphology on the glenohumeral joint force and shoulder muscle force equilibrium: a study of rotator cuff tear and osteoarthritis patients.

Osteoarthritis (OA) and rotator cuff tear (RCT) pathologies have distinct scapular morphologies that impact disease progression. Previous studies examined the correlation between scapular morphology and glenohumeral joint biomechanics through critical shoulder angle (CSA) variations. In abduction, higher CSAs, common in RCT patients, increase vertical shear force and rotator cuff activation, while lower CSAs, common in OA patients, are associated with higher compressive force.

Lower trapezius and latissimus dorsi transfer relieve teres minor activity into the physiological range in Collin D irreparable posterosuperior massive rotator cuff tears: a biomechanical analysis.

Background: Tendon transfers are established techniques to regain external rotation mobility in patients with an irreparable, posterosuperior massive rotator cuff tear (MRCT). Posterosuperior MRCT with intact teres minor (type D MRCT) can lead to excessive teres minor loading to maintain external rotation. We hypothesize that tendon transfers are effective in relieving teres minor loading in type D MRCTs.

Functional and Radiologic Outcomes of Degenerative Versus Traumatic Full-Thickness Rotator Cuff Tears Involving the Supraspinatus Tendon.

Background: Arthroscopic rotator cuff repair (ARCR) is among the most commonly performed orthopaedic procedures. Several factors-including age, sex, and tear severity-have been identified as predictors for outcome after repair. The influence of the tear etiology on functional and structural outcome remains controversial.

How to treat stiffness after proximal humeral fractures?

Shoulder stiffness is a frequent complication after proximal humeral fractures treated with or without surgery. Shoulder stiffness is associated with high rates of absence from work and a significant financial burden for the healthcare system. Secondary stiffness is characterized by additional extracapsular adhesions, including subacromial, subcoracoid, and subdeltoid spaces, usually derived from post-fracture or post-surgical extraarticular hematomas.

Glenoid component placement in reverse shoulder arthroplasty assisted with augmented reality through a head-mounted display leads to low deviation between planned and postoperative parameters.

Background: Navigated augmented reality (AR) through a head-mounted display (HMD) may lead to accurate glenoid component placement in reverse shoulder arthroplasty (RSA). The purpose of this study is to evaluate the deviation between planned, intra- and postoperative inclination, retroversion, entry point, depth, and rotation of the glenoid component placement assisted by a navigated AR through HMD during RSA.

Methods: Both shoulders of 6 fresh frozen human cadavers, free from fractures or other bony pathologies, were used.

Deep-Learning-Based Segmentation of the Shoulder from MRI with Inference Accuracy Prediction.

Three-dimensional (3D)-image-based anatomical analysis of rotator cuff tear patients has been proposed as a way to improve repair prognosis analysis to reduce the incidence of postoperative retear. However, for application in clinics, an efficient and robust method for the segmentation of anatomy from MRI is required. We present the use of a deep learning network for automatic segmentation of the humerus, scapula, and rotator cuff muscles with integrated automatic result verification.

Massive rotator cuff tears with short tendon length can be successfully repaired using synthetic patch augmentation.

Background: Choosing the optimal treatment for massive rotator cuff tears (MRCTs) still poses a surgical problem. In MRCTs with good muscle quality, but short tendon length, nonaugmented repairs lead to high failure rates of up to 90%. The aim of the study was to evaluate midterm clinical and radiologic outcomes of massive rotator cuff tears with good muscle quality, but short tendon length, which were repaired with synthetic patch augmentation.

Effect of PARP-1 Inhibition on Rotator Cuff Healing: A Feasibility Study Using Veliparib in a Rat Model of Acute Rotator Cuff Repair.

Background: PARP-1 (poly[ADP-ribose]) was shown to influence the inflammatory response after rotator cuff tear, leading to fibrosis, muscular atrophy, and fatty infiltration in mouse rotator cuff degeneration. So far, it is not known how PARP-1 influences enthesis healing after rotator cuff tear repair.

Hypothesis/purpose: This study aimed to examine the feasibility of oral PARP-1 inhibition and investigate its influence on rat supraspinatus enthesis and muscle healing after rotator cuff repair.

Glenoid Component Placement Assisted by Augmented Reality Through a Head-Mounted Display During Reverse Shoulder Arthroplasty.

Component positioning is a key factor for avoiding complications and improving functional outcomes in reverse shoulder arthroplasty. Preoperative planning can improve component positioning. However, translating the preoperative plan into the surgical procedure can be challenging.

Residual stability of the distal radioulnar joint following ulnar styloid fracture: influence of the remnant distal radioulnar ligaments.

Clinical studies suggest that even untreated basal ulnar styloid fractures may not affect patient outcomes. This may be due to the remaining parts of the distal radioulnar ligament still attached providing sufficient residual stability of the distal radioulnar joint. We tested this hypothesis in a biomechanical cadaveric model.

Patient-specific instrumentation reduces deviations between planned and postosteotomy humeral retrotorsion and height in shoulder arthroplasty.

Background: Patient-specific instrumentation (PSI) may potentially improve humeral osteotomy in shoulder arthroplasty. The purpose of this study was to compare the deviation between planned and postosteotomy humeral inclination, retrotorsion, and height in shoulder arthroplasty, using PSI vs. standard cutting guides (SCG).