Bone Density Changes at the Origin of the Deltoid Muscle following Reverse Shoulder Arthroplasty.

Background: Reverse total shoulder arthroplasty (RSA) significantly impacts deltoid length, tension, and structure. Studies have extensively investigated various modifications in deltoid characteristics, such as perfusion, elasticity, caliber, histological changes, and strength post-RSA. However, to date, there is a notable absence of research evaluating changes in bone mineral density (BMD) at the deltoid muscle origin after the RSA procedure. Methods: A retrospective analysis of a consecutive series of RSAs performed between May 2011 and May 2022 was conducted. Inclusion criteria comprised primary RSAs with both preoperative and last follow-up shoulder CT scans and a minimum follow-up of 12 months. Trabecular attenuation measured in Hounsfield units (HU) was calculated using a rapid region-of-interest (ROI) method. BMD analysis involved segmenting three ROIs in both pre- and postoperative CT scans of each patient: the acromion, clavicle, and spine of the scapula. Results: A total of 44 RSAs in 43 patients, comprising 29 women and 14 men, were included in this study. The mean follow-up duration was 49 ± 22.64 months. Significant differences were observed between preoperative and postoperative HU values in all analyzed regions. Specifically, BMD increased in the acromion and spine, while it decreased in the clavicle (p-values 0.0019, <0.0001, and 0.0088, respectively). Conclusions: The modifications in shoulder biomechanics and, consequently, deltoid tension post-implantation result in discernible variations in bone quality within the analyzed regions. This study underscores the importance of thorough preoperative patient planning. By utilizing CT images routinely obtained before reverse shoulder replacement surgery, patients at high risk for fractures of the acromion, clavicle, and scapular spine can be identified.

Reverse Shoulder Prosthesis for Proximal Humeral Fractures: Primary Treatment vs. Salvage Procedure.

Background: The optimal treatment for complex proximal humerus fractures (PHFs) lacks consensus, with reverse total shoulder arthroplasty (RTSA) often being a final resort rather than a primary approach. This study aimed to compare outcomes and satisfaction rates of primary RTSA for PHFs versus salvage RTSA for previously unsuccessful treatments. We hypothesized that primary RTSA would yield superior clinical outcomes, functional scores, and patient satisfaction. Methods: A retrospective analysis of RSA procedures between 2011 and 2021 was conducted, focusing on primary RTSA for PHFs or salvage RTSA for failed osteosynthesis. Patients meeting inclusion criteria underwent clinical and radiological follow-up for at least two years. Demographic characteristics, outcomes scores, and range of motion (ROM) were assessed. Results: Of 63 patients, 42 underwent primary RTSA and 21 underwent salvage RTSA. The median follow-up was 50 months. Statistically significant differences favored primary RTSA in forward flexion, abduction, internal rotation, and Constant shoulder score. Patient satisfaction levels did not significantly differ between groups. Complications occurred in 7.15% of primary RTSA cases and 14.28% of salvage RTSA cases. Conclusions: Primary RTSA may yield slightly better outcomes and lower complication rates compared to salvage RTSA. Further prospective studies are necessary to validate these findings.

What We Should Expect from an Innovative Intra-Articular Hyaluronic Acid Product: Expert Opinion Based on a Comprehensive Review of the Literature.

BACKGROUND: Intra-articular hyaluronic acid (IAHA) products are often used in the treatment of adults with mild-to-moderate knee osteoarthritis (KOA). The International Symposium on Intra-Articular Treatment (ISIAT) convened a multidisciplinary technical expert panel to define characteristics for an innovative IAHA product that should answer unmet needs in the clinical management of adults with mild-to-moderate KOA. METHODS: An initial set of evidence-based statements was developed based on data extracted from articles identified through a comprehensive literature search. A Delphi panel comprising 19 experts in KOA voted in 3 rounds to rate their degree of agreement with accepted statements. RESULTS: The final set of 13 accepted statements focus on the effect of an innovative IAHA across 5 key domains of nociceptive pain, joint function, quality of life, joint structure and integrity, and adverse effects. The statements set thresholds for clinically meaningful improvements that exceed those generally achievable by currently available IAHA products. CONCLUSION: The characteristics described by these statements from the ISIAT set new standards for what should be expected from an innovative IAHA. These statements should serve as a framework for driving the development of innovative IAHA products that will surpass the actual outcomes achieved by current viscosupplements in patients with mild-to-moderate KOA.

Unicompartmental knee arthroplasty (UKA) for primary spontaneous osteonecrosis of the knee (SONK): a systematic review.

Introduction: The role of unicompartmental knee arthroplasty (UKA) in spontaneous osteonecrosis of the knee (SONK) is still controversial. Materials and methods: We performed a systematic review to evaluate all available current literature on UKA in the setting of SONK. A comprehensive electronic research was performed using the PubMed, Embase, Web of Science, and Cochrane databases with keywords related to SONK and knee arthroplasty. Studies were selected with predetermined inclusion criteria: 1) studies that specifically assessed SONK treated with UKA; 2) studies reporting implant survival rate and global clinical outcomes; 3) studies with a minimum follow up of 1 year. We excluded articles not written in English, articles that did not differentiate between primary and secondary osteonecrosis and articles published before 2000. Results: The overall research process produced 19 studies. We extrapolated data of a total of 717 unicompartimental knee arthroplasty procedures (1,39% lateral UKA, 98,61% medial UKA). Extracted data include years of follow-up, patient demographics, laterality of lesion, radiological findings, unicompartimental knee arthroplasty implants, reason of revision, revision rate, maximum knee flexion, knee clinical outcomes score, and Kaplan-Meier survival curves. The data collected show that UKA had acceptable survival rates as well as revision rates and good clinical outcomes both in the short- and long-term. Conclusion: UKA is an optimal treatment choice for primary SONK when correctly indicated in a carefully selected subset of patients, with no significant difference compared to osteoarthritis. Attention must be paid to distinguish the primary from secondary SONK, as the latter could lead to worse outcomes.

Meniscal extrusion: risk factors and diagnostic tools to predict early osteoarthritis.

Meniscal extrusion (ME) is strongly correlated with cartilage wear and osteoarthritis (OA), be-cause of the altered kinematic and the decreased contact area between the tibia and femur. The aim of this narrative review is to analyze the process of ME, focusing on the possible causes, and to evaluate the correlation between ME and knee OA, in order to provide early diagnosis and treatments. Studies written in English that analyzed the causes of ME, provided indications re-garding diagnosis and treatment, and evaluated the relation between ME and early OA were in-cluded. Injuries, degeneration of the meniscal substance and meniscus root tears are associated with significantly increased ME. An extruded meniscus could be a manifestation of other pa-thologies such as disruption of coronary ligaments, cartilage loss, knee malalignment, ligament injuries, or OA. ME is strongly associated with osteoarthritis features, particularly with bone marrow lesion and cartilage damage. Magnetic resonance imaging represents the gold standard for the detection of ME. The severity of the medial meniscus extrusion may also affect healing af-ter repair, and meniscus extrusion is not completely reduced by meniscus posterior root tear re-pair. In this study, we proved that ME represents an important risk factor for early knee OA. We provided alternative theories of ME, such as meniscal fibers injury first and "dynamic extrusion of the menisci". The phenomenon of aging has been described as a new concept in the etiology of ME. Finally, we stated all the main techniques and characteristics of the diagnostic process, as well as the current knowledge in the therapeutic field.