Citations

Abstract » A thorough understanding of glenoid deformity is essential to anticipate intraoperative needs and manage bony deficiencies. Management strategies include eccentric reaming, alternate scapular line baseplate orientation, bone grafting, or metallic augmentation as either “off-the-shelf” or custom baseplates. Accurate implantation of the glenoid component in the presence of glenoid bone loss (GBL) may also benefit from shoulderspecific guides, navigation, or robotic assistance. » GBL can negatively affect outcomes due to compromised bony fixation, altered soft tissue tensioning, and component malposition, which can contribute to impingement, dislocation, aseptic loosening, polyethylene wear, and component failure. » In this article, we provide a comprehensive review of published literature regarding the management of GBL in primary RSA and provide additional insight on the effectiveness of current approaches to manage bony deficiency.

Background: Recurrent anterior shoulder instability may lead to capsuloligamentous and bony lesions of the glenoid and humerus. To date, there is no clear consensus on how to best measure anterior glenoid bone loss (GBL) in the setting of recurrent instability. The objective of this study, therefore, was to evaluate the accuracy and reliability of 7 different methods of measuring anterior GBL on three-dimensional models based on computed tomography. Methods: Eight levels of GBL in the anterior and anteroinferior directions were virtually generated in 14 three-dimensional healthy glenoid models. GBL was measured with 7 different methods: based on a height/width ratio (M1), based on surface area within a circle (M2 and M3), based on linear distance within a circle, (M4, M5, and M6), and based on a volume ratio (M7). For each method, the measurement accuracy was assessed by comparing the calculated value with the true amount of generated GBL. The measurement reliability was assessed by computing the score variance and intraclass correlation coefficient. Results: The most accurate (average measurement error of <2% and largest proportion with error <5%) and reliable (ICC >0.96) measurement methods for GBL were M2 (based on surface area) and M5 (based on the linear distance). The average measurement error for the other methods ranged between 3% and 11% for anterior GBL and between 2% and 9% for anteroinferior GBL. For anterior GBL, the measurement increased by an average of 0.5% for each 1% increase in circle radius, leading to an overestimation of GBL with a larger circle diameter Conclusion: The methods for calculating glenoid bone loss performed better for the more common direct anterior bone loss rather than the less common anteroinferior-directed bone loss. Both an area-based method (M2) and linear distance–based method (M5) resulted in accurate and reliable measurements of glenoid bone loss; however, the linear distance–based methods may be easier to perform clinically. The height-width ratio and volume methods were less accurate and reliable. Level of Evidence: Level IV ; case series; diagnostic studies. See Instructions for Authors for a complete description of levels of evidence.

AimsTo characterize the effects of varying experimental parameters of transforming growth factor-beta 1 (TGF-β1) in primary knee fibroblasts as an in vitro model of arthrofibrosis.MethodsPrimary knee fibroblasts were isolated from one patient undergoing primary total knee arthroplasty (TKA) and one patient undergoing revision TKA for arthrofibrosis, respectively. Fibroblasts were stimulated with varying concentrations and durations of the pro-fibrotic cytokine TGF-β1. Picrosirius red staining (PSR) was conducted to assess collagen deposition, and real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting were performed to determine cellular gene expression levels. A collagen gel contraction assay was used to assess TGF-β1-induced fibroblast contraction.ResultsIn our experiments, TGF-β1-mediated collagen deposition was consistent across a vast concentration range (0.5 to 40 ng/ml). While α-smooth muscle actin (ACTA2) protein levels and SMAD2 phosphorylation were induced by low concentrations (1 ng/ml), robust ACTA2 transcription required higher concentrations (5 ng/ml) of TGF-β1. Evaluation of TGF-β1-mediated cell and cytoskeletal contractility shows that in the measured fibroblasts, this process occurs within three hours following TGF-β1 administration. Of note, TGF-β1-differentiated myofibroblasts exhibited greater contractile properties than naïve fibroblasts in the presence of TGF-β1.ConclusionTaken together, this study elucidates key TGF-β1 experimental parameters that will inform the development and interpretation of in vitro models of arthrofibrosis.Cite this article: Bone Joint Res 2025;14(6):527–538.

Experimental analyses of knee joint contractures have traditionally utilized a 6-month rabbit model as the gold standard. However, this model is time-intensive and costly. The purpose of this study was to develop an abbreviated rabbit model of knee contractures and compare it to the well-established longer model. Twenty female New Zealand White rabbits were divided into two equal groups and prospectively studied to assess knee passive extension angles (PEA), contracture angles (CA), and terminal posterior capsular stiffness. Experimental knees were immobilized for either 4 weeks ( n = 10) with an 8-week remobilization period in the abbreviated model (i.e., 3 months) or for 8 weeks ( n = 10) with a 16-week remobilization period in the standard model (i.e., 6 months). PEAs were assessed at remobilization and several time points using differing vertical forces. At sacrifice, terminal biomechanical data were collected to assess posterior capsular stiffness. Analysis of PEAs in live animals at each torque value and time point demonstrated increased PEAs and decreased CAs in the 3-month abbreviated model as compared to the 6-month standard model. At sacrifice, biomechanical analysis demonstrated that the posterior capsules of the 3-month experimental limbs were significantly more stiff than the contralateral limb (2.4 vs. 0.05 Ncm/°, p < 0.0001), but significantly less stiff compared to the 6-month experimental limbs (2.4 vs. 4.7 Ncm/°, p < 0.0001). Our study suggests that the 6-month standard rabbit knee model of arthrofibrosis should continue to be used in the laboratory assessment of arthrofibrosis. However, the abbreviated model may be beneficial under selected experimental conditions.

AimsTo evaluate the role of autophagy in primary knee fibroblasts undergoing myofibroblast differentiation as an in vitro model of arthrofibrosis, a complication after total knee arthroplasty characterized by aberrant intra-articular scar tissue formation and limited range of motion.MethodsWe conducted a therapeutic screen of autophagic-modulating therapies in primary human knee fibroblasts undergoing transforming growth factor-beta 1 (TGF-β1)-mediated myofibroblast differentiation. Autophagy was induced pharmacologically with rapamycin or by amino acid deprivation. Picrosirius red staining was performed to quantify collagen deposition. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were conducted to evaluate fibrotic gene expression levels.ResultsRapamycin, an mTOR complex 1 (mTORC1) inhibitor and autophagy inducer, reduced TGF-β1-mediated collagen deposition. Interestingly, we simultaneously report that myofibrogenic genes, including ACTA2, were highly upregulated following rapamycin-TGF-β1 treatment. When autophagy was induced through amino acid deprivation, we demonstrated suppressed extracellular matrix levels, fibrotic gene expression (e.g. ACTA2), and SMAD2 phosphorylation levels in TGF-β1-stimulated fibroblasts.ConclusionOur findings demonstrate that the induction of cellular autophagy suppresses TGF-β1-induced collagen deposition in primary human knee fibroblasts. Taken together, these data suggest that cellular autophagy may be prophylactic against the pathogenesis of arthrofibrosis.Cite this article: Bone Joint Res 2025;14(4):328–337.

Background: No biomechanical study has established the effect of different graft positions or bone block options on anterior glenohumeral joint stability. Purpose/Hypothesis: The purpose of this study was to compare graft choice (distal clavicular vs coracoid autograft for Latarjet) and position on stability of the bone block for anterior glenohumeral instability. It was hypothesized that both grafts would be comparable if flush with the glenoid but that the sling effect of the Latarjet procedure would lead to greater stability in case of graft medialization. Study Design: Controlled laboratory study. Methods: Eight cadaveric shoulders were included. Defects stabilized using a distal clavicular graft and a coracoid graft were consecutively positioned at 0, 4, and 8 mm medially. The starting position was determined by the humeral head’s being seated at its most medial position on the glenoid surface. Each experiment comprised maximal external rotation and glenohumeral abduction at 60° while applying a constant 50-N medial compressive force to the humerus under all conditions. The conjoint tendon was routed through a split in the subscapularis and loaded with a 5-N weight using a pulley system for all Latarjet trials to simulate the sling effect. Results: Regarding the clavicular graft, the stability ratio significantly decreased versus the intact condition at all medial offsets ( P = .007 for 0 mm, P < .001 for 4 mm, and P < .001 for 8 mm), and it was significantly lower in the 4-mm versus 0-mm position ( P = .008), significantly higher in the 4-mm versus 8-mm position ( P < .001), and significantly lower in the 8-mm versus 0-mm position ( P < .001). Regarding the coracoid graft, the stability ratio was comparable with intact for the 0-mm position ( P = .12), while it was significantly lower in the 4-mm and 8-mm positions ( P < .001 for both). The distal clavicular graft at 0-mm offset was comparable with the coracoid graft at 0-mm offset. Conclusion: In shoulders with anterior glenoid bone loss, the coracoid and distal clavicular autografts were biomechanically comparable when placed flush with the glenoid. The distal clavicle at 0-mm offset did not restore stability compared with the intact specimen, but the Latarjet at 0-mm offset was not significantly different from the intact condition. Clinical Relevance: The Latarjet procedure provides higher stability compared with distal clavicular autograft when medialized.

The integration of immersive virtual reality (IVR) in orthopedic surgery offers a platform for surgeon-to-surgeon collaboration. This paper explores a new use case of IVR-based collaboration among orthopedic surgeons, focusing on three key areas: surgical training, procedural planning, and remote peer to peer collaboration. Immersive virtual reality enables surgeons to engage in immersive, interactive environments where complex anatomical structures and surgical techniques can be visualized in three dimensions. This fosters more efficient communication, precise surgical planning, shared learning experiences and an opportunity to enhance 3D visual spatial intelligence. This case study highlights how surgeons in different geographic locations can collaborate, sharing knowledge and expertise in real time without the constraints of physical presence. This connectivity provides a platform for skill acquisition, and the practice of surgical techniques while creating an opportunity for a mentor to educate a remote learner. Moreover, IVR facilitates the rehearsal of a procedure, potentially contributing to improved patient outcomes by reducing errors and enhancing preoperative planning and education. In the context of orthopedic surgery, the ability to virtually simulate surgeries in a collaborative setting represents a novel advancement. IVR also allows for the customization of surgical scenarios, providing surgeons with repeated exposure to common and rare, complex cases, thus broadening their experience base. By supporting a connected surgical community, IVR-based surgeon-to-surgeon collaboration has the potential to create opportunities for educators and learners to connect and learn in a meaningful manner.

Introduction Reverse shoulder arthroplasty (RSA) is performed for various shoulder pathologies. Inadequate tensioning of the deltoid muscle can lead to complications, highlighting the need for optimization. Preoperative quantification of deltoid health may improve operative execution and outcomes. Shear wave elastography (SWE) quantifies stiffness as a marker for muscle health and tensioning. This study establishes normal reference values for the deltoid in healthy individuals. Methods 40 participants were enrolled, 10 in each 18–30, 31–40, 41–55, and 55 + age groups. Two operators performed SWE in 3 deltoid regions, and the intra- and inter-operator agreement was assessed. Results Mean values were 23.2 ± 4.6, 26.4 ± 5.6, and 17.9 ± 5.2 kPa for the anterior, lateral, and posterior regions. The posterior region did not show any age dependency. However, there were significant differences between the age groups of 18–30 and 55 + years in the anterior (19.7 ± 3.7 vs. 26.7 ± 5.3 kPa) and lateral (22.0 ± 5.4 vs. 30.2 ± 8.8 kPa). Intra-operator reliability ranged from 0.45 to 0.60, and inter-reader agreement from 0.57 to 0.85. Conclusion This study provides reference values of deltoid stiffness which could serve as a comparison with clinical measurements for RSA operative planning and execution and prediction of surgical outcomes.

Periprosthetic joint infection represents a devastating complication after total elbow arthroplasty. Several measures can be implemented before, during, and after surgery to decrease infection rates, which exceed 5%. Debridement with antibiotics and implant retention has been reported to be successful in less than one-third of acute infections, but still plays a role. For elbows with well-fixed implants, staged retention seems to be equally successful as the more commonly performed two-stage reimplantation, both with a success rate of 70% to 80%. Permanent resection or even amputation are occasionally considered. Not uncommonly, a second-stage reimplantation requires complex reconstruction of the skeleton with allografts, and the extensor mechanism may also be deficient. Further developments are needed to improve our management of infection after elbow arthroplasty.Cite this article: Bone Joint J 2024;106-B(11):1321–1326.

Background: Surgical repair of full thickness biceps tears has demonstrated adequate outcomes in short and mid-term studies. However, data on the long-term outcomes of full thickness distal biceps injuries and their treatment are currently lacking. Purpose/Hypothesis: The purpose of this study was to report on patient demographics, injury characteristics, and long-term outcomes for patients with full-thickness distal biceps tears. It was hypothesized that complete distal biceps tears managed operatively would demonstrate robust clinical success at long-term follow-up. Study Design: Case series; Level of evidence, 4. Methods: Patients with magnetic resonance imaging–confirmed, complete distal biceps tendon rupture sustained between 1996 and 2016 were identified. Patients were cross-referenced with a regional geographic database. Results: A total of 66 patients (3 female, 63 male) with a median age of 50.8 years (IQR, 41.5-60.4) and a median clinical follow-up of 14.7 years (IQR, 9.6-17.9 years) were included. Patients who sustained a full-thickness distal biceps tendon tear were likely to be in their early 50s, male, right-hand dominant, current/former smokers, and laborers with a history of traumatic injury during an intentional movement. Most of these patients had pain and supination weakness but no loss of range of motion. All included tears were treated operatively. At final follow-up, patients maintained a majority of near-normal range of motion (median total arc of flexion/extension 140° and supination/pronation 80°), excellent elbow flexion strength (91% of patients had full strength), and adequate elbow supination strength (76% of patients had full strength). The overall complication rate was 24%, with 16 out of 66 patients experiencing some type of complication between infection, rerupture, heterotopic ossification, reoperation, and nerve complications. Overall return to work was 98%, and 85% of those who returned to work did so without restrictions. Conclusion: Complete tears of the distal biceps were most common in patients 50 years of age, male sex, right-hand dominant, and current/former smokers. The most common profession was laborer, and injuries were primarily traumatic in nature during intentional activity. Patients managed operatively demonstrated high rates of success at long-term follow-up with respect to elbow function and clinical outcomes.