The size of the Hill Sachs defect increases during reduction of a first time shoulder dislocation in older adults: a pilot study in 20 cases.

PURPOSE: To evaluate if the size of Humeral Hill-Sachs Defects (HSDs) increases during reduction in the emergency department (ED) in subjects that have a first-time anterior shoulder dislocation. METHODS: Subjects more than 18 years old presenting to the ED a first-time anterior shoulder dislocation were included. A computed tomography was performed prior to any reduction attempt (Pre-CT). The shoulder was reduced in the emergency room with intraarticular lidocaine; if two attempts failed, the shoulder was reduced under anaesthesia. A second CT was performed after reduction of the shoulder (Post-CT). CT were evaluated using the Osirix software. A 3-dimensional reconstruction of the humeral head was performed and the maximum width of the humeral defect, maximum depth of the humeral defect and total volume of the humeral defect were measured. The relative increase in size was calculated. RESULTS: Twenty subjects were included in the study. All subjects presented HSDs in the Pre-CT that had a width of a median of 9.9(interquartile range:2.9)mm, a depth of 7.0(3.0]mm and a volume of 355(333)mm2. The HSD in the Post-CT had a width of 10.9(3.0)mm (an increase of 7.23[8.5]%, significant differences, p = 0.0001) a depth of 7.2(2.7)mm (an increase of 9.93[20.7]%, significant differences, p < 0.0001) and a volume of 469(271) mm2 (an increase of 27.5[26.9]%, significant differences, p < 0.0001). There were size increases larger than 25% in 15/20 (75%) of subjects. CONCLUSION: Standard reduction manoeuvres performed in a first-time anterior shoulder dislocation increase the size of the HSD. This increase in size is larger than 25% in four out of five cases. LEVEL OF EVIDENCE: IV, prospective cases series study.

Advanced Hydrogel-Based Strategies for Enhanced Bone and Cartilage Regeneration: A Comprehensive Review.

Bone and cartilage tissue play multiple roles in the organism, including kinematic support, protection of organs, and hematopoiesis. Bone and, above all, cartilaginous tissues present an inherently limited capacity for self-regeneration. The increasing prevalence of disorders affecting these crucial tissues, such as bone fractures, bone metastases, osteoporosis, or osteoarthritis, underscores the urgent imperative to investigate therapeutic strategies capable of effectively addressing the challenges associated with their degeneration and damage. In this context, the emerging field of tissue engineering and regenerative medicine (TERM) has made important contributions through the development of advanced hydrogels. These crosslinked three-dimensional networks can retain substantial amounts of water, thus mimicking the natural extracellular matrix (ECM). Hydrogels exhibit exceptional biocompatibility, customizable mechanical properties, and the ability to encapsulate bioactive molecules and cells. In addition, they can be meticulously tailored to the specific needs of each patient, providing a promising alternative to conventional surgical procedures and reducing the risk of subsequent adverse reactions. However, some issues need to be addressed, such as lack of mechanical strength, inconsistent properties, and low-cell viability. This review describes the structure and regeneration of bone and cartilage tissue. Then, we present an overview of hydrogels, including their classification, synthesis, and biomedical applications. Following this, we review the most relevant and recent advanced hydrogels in TERM for bone and cartilage tissue regeneration.

Arthroscopic Bankart repair with all-suture anchors does not cause important glenoid bone osteolysis: a volumetric CT study of 143 anchors.

PURPOSE: To evaluate with computed tomography (CT) the incidence of anchor-related osteolysis after implantation of two types of all-suture anchors for the management of labral lesions in shoulder instability. METHODS: Single-cohort, observational study with 12-month follow-up. Thirty-three participants (27 males/6 females; age 38.3 years [SD 11.3]) with anterior labral lesions in which 143 all-suture anchors (71 Iconix 1.4 mm and 72 Suturefix 1.7 mm) were implanted were evaluated with a CT performed a mean of 15.4 [3.85] months after surgery. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (defects larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (defects larger than twice the drill volume). RESULTS: No bone defect was identified in 16 anchors (11.2%, [95% CI 6.5-17.5%]). A partial bone defect was found in 84 anchors (58.7% [50.2-66.9%]). Tunnel enlargement was found in 43 anchors (30.11% [22.6-37.6%]). No anchor caused cystic lesions (0% [0-2.5%]). The defect volume was a mean of 27.8 mm3 (SD 18.4 mm3, minimum 0 mm3, maximum 94 mm3). Neither the position in the glenoid nor the type of implant used had a significant effect in the type or size of the defects. CONCLUSION: When using all-suture anchors in the glenoid during instability surgery, relevant bone osteolytic defects are rare at 1-year follow-up. Most anchor insertion tunnels will fill completely (11%) or partially (59%) with bone. Tunnel enlargement will develop in 30% of anchors. No cystic defects larger than 0.125 cm3 were observed. There is a low risk that all-suture anchors cause significant osteolytic bone defects in the glenoid. These implants can be used safely. Level of evidence IV.

Arthroscopic remplissage with all-suture anchors causes cystic lesions in the humerus: a volumetric CT study of 55 anchors.

PURPOSE: To evaluate with computed tomography (CT) the incidence of implant-related osteolysis after implantation of two types of all-suture anchors during remplissage for the management of Hill-Sachs lesions in shoulder instability. METHODS: Single-cohort, observational study with a minimum of 12 months follow-up. Twenty-five participants (19 males and 6 females; mean age 37.4 years [SD: 11.6]) with Hill-Sachs lesions requiring remplissage were evaluated with a CT performed a mean of 14.1 [3.74] months after surgery. Fifty-five all-suture anchors (19 2.3 mm Iconix and 36 1.7 mm Suturefix) were used. The volume of the bone defects was measured in the CT. Every anchor was classified into one of four groups: (1) no bone defect. (2) Partial bone defect (bone defects smaller than the drill used for anchor placement). (3) Tunnel enlargement (bone defect larger than the drill volume but smaller than twice that volume). (4) Cystic lesion (bone defect larger twice the drill volume). RESULTS: No bone defect was identified in only two anchors (3.6%, 95% CI 0.4-12.5%). A partial bone defect was found in eight anchors (14.5%, 95% CI 6.5-26.7%). In 35 anchors (63.6%, 95% CI 49.6-76.2%), there was enlargement of the bone defect that was smaller than 200% the size of the drill used. Ten anchors caused bone defects larger than twice the size of the drill used (18.2%, 95% CI 9.1-30.9%). The defect size was a mean of 89 mm3 (SD: 49 mm3, minimum 0 mm3, maximum 230 mm3). CONCLUSION: When using all-suture anchors in arthroscopic remplissage during instability surgery, relevant bone osteolytic defects are common at 1-year-follow-up. Cystic defects larger than twice the volume of the resected bone during implantation develop in one in six anchors and significant tunnel widening will develop in another three out of five anchors. This bone loss effectively increases the size and depth of the Hill-Sachs lesions but does not seem to affect short-term clinical outcomes. LEVEL OF EVIDENCE: Level IV.

Risk of neurological injury in posterior bone block surgery for recurrent glenohumeral instability: a cadaveric study.

INTRODUCTION: Recurrent posterior glenohumeral instability poses a challenge for treatment. Bone block procedures have been advocated in cases where a bony defect is present. However, these techniques are not free of complications due to the proximity of neurovascular structures. The aim of this study is to measure the distance to the axillary and suprascapular nerves at the different steps of the procedure. MATERIALS AND METHODS: Ten frozen human cadavers were used. The bone graft was prepared and placed on the posterior aspect of the glenoid, where it was fixed with two K-wires in different positions: parallel to the articular surface and with 20° of medial angulation. The distance from the entry and exit points of the K-wires to the axillary and suprascapular nerves was measured. RESULTS: At the exit point, mean distance from the superior K-wire to the axillary nerve was 4.4 mm in the neutral position and 14.4 mm when medially angulated (p = 0.01) and 2.6 mm and 11.5 mm, respectively, for the inferior K-wire (p < 0.01). No differences were found at the entry point (p = 0.7 and p = 0.3). For the suprascapular nerve, mean distance to the entry point of the superior K-wire was significantly greater when it was inserted with 20° of medial angulation than when placed in neutral position (p = 0.04). No differences were found for the inferior K-wire (p = 0.35). CONCLUSION: Posterior bone block surgery should be performed taking into consideration the possibility of axillary nerve injury anteriorly at the exit point of the K-wires. Wire and screw insertion parallel to the glenoid articular surface may reduce the risk, while increased wire or screw medial angulation with respect to the glenoid surface may heighten risk. LEVEL OF EVIDENCE: Not applicable (cadaveric study).