Calcific tendinitis (CT) is a condition that most commonly affects the rotator cuff tendons of the shoulder joint. Fundamental crystal morphology and composition underlying different radiological stages of CT remained insufficiently characterized. We collected human tendon samples from 33 patients with CT and 12 control patients. CT patients exhibited an increased incidence of comorbidities, especially high blood pressure and disorders of fat metabolism. Based on the Gärtner classification, calcific deposits were classified as type I in two patients, type II in 14 patients, and type III in 17 patients. Tendon calcification of the controls was significantly lower compared to the CT group. No differences in the amount of histological calcification between the Gärtner groups were observed. A correlation between the radiological size of calcification and the amount of calcification detected in histology was found. SEM-EDS and Raman identified basic calcium phosphate to be the predominant crystal type in tendons from CT patients, with only two calcium pyrophosphate detections. CT is mainly associated with BCP deposition. Calcified depot size was associated with pain intensity, while diabetes mellitus was observed more frequently in CT patients than in controls. BCP may be a focus of future mechanistic studies on CT.

Osteoarthritis (OA) of the knee is characterized by cartilage matrix degeneration, which eventually leads to joint dysfunction and surgical replacement. Preoperative radiography, the standard for treatment decision making, provides limited information on the extent of degeneration, emphasizing the need for quantitative intraoperative techniques. This study evaluates the potential of vibroacoustic signals generated from instrument–tissue interactions to assess cartilage degeneration severity. A total of 136 ex vivo cartilage specimens of varying degeneration severity, histologically graded using the OARSI score, were collected from 41 patients undergoing arthroplasty. The specimens were classified into three groups: healthy cartilage (OARSI ≤2.0), degenerated cartilage (OARSI ≥ 2.5), and subchondral bone. Vibroacoustic signals were captured during specimen palpation using a vibration measurement system affixed to a surgical probe. 26 characteristic signal features were extracted using Continuous-Wavelet Transformation, and their discriminative power was assessed using Support Vector Machine and k-Nearest-Neighbor classifiers under patient- and specimen-level grouped cross-validation with nested hyperparameter tuning. Bone was distinguished from cartilage with 84–91% recall. Healthy cartilage (OARSI ≤2.0) was identifiable with 74–80% sensitivity, whereas the specificity for degenerated cartilage (OARSI ≥ 2.5) remained limited (40–57%), constituting the principal limitation of the approach. Interpreting the binary cartilage classification as a diagnostic test, a receiver-operating characteristic (ROC) analysis yielded an area under the curve (AUC) of up to 0.66 (95% CI [0.56, 0.76]). The study demonstrates that vibroacoustic signals from instrument–tissue interactions may provide complementary information for intraoperative cartilage evaluation and may contribute to decision making in arthroplasty, while the reliable grading of cartilage degeneration remains an open challenge.

Background/Objective: Postoperative recovery after spine surgery varies substantially and cannot be fully explained by structural pathology alone. This study evaluates postoperative outcomes using a structured 2 × 2 Surgical Trauma Gradient integrating exposure-related invasiveness (minimally invasive vs. open) and biomechanical strategy (decompression vs. fusion), and examines the modifying role of Type-D personality. Methods: This observational cohort study included 200 patients undergoing elective spine surgery. Patients were stratified into four surgical subgroups: minimally invasive decompression, open decompression, minimally invasive fusion, and open fusion. Primary outcomes included pain intensity (Visual Analog Scale), functional disability (Oswestry Disability Index), patient satisfaction (Patient Satisfaction Index), and postoperative complications at 12-month follow-up. Surgical invasiveness was modeled both categorically and as an ordinal gradient. Multivariable regression, logistic regression, interaction analysis, and longitudinal mixed-effects models were applied. Results: Postoperative outcomes demonstrated a consistent gradient across increasing surgical burden. In multivariable models, higher surgical invasiveness independently predicted greater residual pain (β = 0.69; 95% CI 0.55-0.82; p < 0.001) and higher functional disability (β = 6.20; 95% CI 5.10-7.30; p < 0.001). Increasing invasiveness was also associated with lower patient satisfaction (β = -0.38; 95% CI -0.47 to -0.29; p < 0.001) and higher complication risk (OR = 1.64; 95% CI 1.12-2.41; p = 0.01). Type-D personality independently predicted worse postoperative pain (β = 0.41; p = 0.008) and significantly modified the association between surgical burden and pain (interaction β = 0.22; p = 0.012). Conclusions: Postoperative outcomes follow a structured Surgical Trauma Gradient influenced by both surgical burden and psychosocial vulnerability, particularly Type-D personality. Integrating these dimensions may improve perioperative risk stratification and support individualized treatment strategies.

Accurate identification of implants in total knee arthroplasty (TKA) is essential for revision arthroplasty but is often complicated by incomplete documentation. While convolutional neural networks (CNNs) achieve high accuracy in implant recognition, the role of multimodal large language models (LLMs), such as ChatGPT remains unclear. This study combined a retrospective radiographic analysis of 80 bicompartmental TKA cases with a structured comparison of CNN-based classification and LLM-based interpretive reasoning. The analysis included four implant systems. Convolutional neural networks served as benchmark references, while a multimodal large language model (ChatGPT) was evaluated for implant identification, reasoning, and confidence estimation. Radiographs in anteroposterior projection showed higher recognition performance than lateral views across all systems. The combined use of both projections improved reliability, indicating dependence on complementary morphological features. Convolutional neural network-based approaches achieved accuracies exceeding 99

In the original publication [...].

BACKGROUND:Chronic postoperative pain is a common and often insufficiently treated complication that is closely linked with depressive and anxiety symptoms. OBJECTIVE:To investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) reduces postoperative pain and if depressive or anxiety symptoms modulate the treatment effects. METHODS:In a three-arm, double-blind, randomized controlled trial, 44 patients undergoing joint replacement surgery were allocated to an intervention group (n = 15), sham group (n = 17), or treatment as usual (TAU) control group (n = 12). Assessments were conducted at hospital admission (T0) and before discharge (T1) using the Short-Form McGill Pain Questionnaire (SF-MPQ), the Patient Health Questionnaire‑9 (PHQ-9) and the Generalized Anxiety Disorder 7 (GAD-7). Data were analyzed using mixed-design ANOVA and linear mixed-effects regression models with a Bonferroni correction. RESULTS:There were no significant main or interaction effects of group, time, or group × time on pain intensity (F(2,18) = 0.04, p = 0.959, η2 = 0.003; F(1,18) = 0.89, p = 0.358, η2 = 0.015). The PHQ‑9 scores showed trends for group and time effects (F(2,21) = 5.96, p = 0.009, η2 = 0.322; F(1,21) = 5.06, p = 0.035, η2 = 0.038). The GAD‑7 did not reveal significant effects. Moderation analyses did not indicate any significant effects of depressive or anxiety symptoms on pain change and combined moderation was not significant either. CONCLUSION:In the present study, taVNS did not reduce postoperative pain and showed no moderating effects of depression or anxiety. Standardization of stimulation parameters, inclusion of psychological and somatic comorbidities and longer high-frequency follow-up periods are needed for future studies.

Background:The diagnosis of periprosthetic joint infection (PJI), and particularly low-grade ((LG) PJI) infections, remains a clinical challenge. Systemic inflammatory markers sometimes yield false-negative results in inapparent cases, complicating the differentiation from aseptic loosening (AL). This exploratory study evaluated tissue-based complement factors C3 and C5 as biomarkers compared to terminal factor C9 and established systemic parameters. Methods:Fifty-five patients undergoing revision arthroplasty were categorized into high-grade PJI (HG) PJI, N = 20), (LG) PJI (N = 14), and AL (N = 21). Serum parameters (C-reactive protein (CRP), white blood cells (WBC)) were analyzed by immunohistochemistry for tissue-based C3, C5, and C9. Diagnostic performance was assessed via ROC analysis. Results:Pathogen spectra differed significantly, with (LG) PJI dominated by Cutibacterium acnes and (HG) PJI by staphylococci. ROC analysis showed that serum CRP accurately identified (HG) -PJI, but failed in (LG) PJI. WBC demonstrated limited accuracy. In contrast, C3 detection in tissues exhibited superior performance, particularly for identifying (LG) PJI versus (HG) PJI. C5 detection remained robust in both PJI types. Terminal factor C9 yielded lower overall discrimination and significant cross-reactivity in AL cases. Conclusions:Central complement factors C3 and C5 serve as robust tissue biomarkers for PJI, outperforming C9 and systemic parameters. Their implementation may improve clinical decision-making, especially in (LG) PJI cases, where standard diagnostic criteria remain inconclusive.

Abstract The continuous enhancement of orthopedic implant surfaces is essential to improving biological integration and minimizing infection-related complications. This work introduces an approach of functional surface modification for metallic implant materials that combines compositional tuning with controlled structural design. The strategy addresses key limitations of conventional implant surfaces by integrating antibacterial functionality and osteogenic support within a single surface system. The developed modification concept involves the formation of a biofunctional layer on metallic substrates, incorporating specific elements or compounds with known antibacterial and cell-stimulating properties. In parallel, the surface morphology is tailored on the micro- and nanoscale through controlled processing to guide cellular attachment and differentiation. The resulting architecture aims to establish a biologically active interface capable of modulating cell–surface interactions and reducing bacterial adhesion. This dual approach enables a tunable balance between antibacterial efficacy and osseointegrative potential, adaptable to various implant materials and design requirements. The modified surfaces were characterized in terms of their morphological, chemical, and biological properties using complementary analytical and in-vitro evaluation techniques. Particular emphasis was placed on correlating structural and compositional parameters with biological performance indicators such as cell adhesion, proliferation, and microbial response. These investigations provide a comprehensive understanding of how engineered surface features contribute to the functional behaviour of implant materials under physiological conditions. Overall, the presented concept demonstrates the effectiveness of combining compositional functionalization with controlled topographical design in developing next-generation implant surfaces. The adaptability of the approach to different metallic substrates and processing routes highlights its potential for translation into various orthopaedic implant applications, providing a versatile pathway toward improved clinical outcomes and the prevention of periprosthetic joint infections (PJI).

Abstract Purpose Long-segment fusion terminating at the sacrum is associated with a substantial risk of distal mechanical complications, including screw loosening and pseudarthrosis. Whether spinopelvic fixation is associated with improved construct durability and maintenance of sagittal alignment compared with sacral-only fixation remains clinically relevant. Methods This retrospective single-center cohort study included 100 adult patients undergoing posterior long-segment fusion involving four or more motion segments terminating at the sacrum between 2000 and 2024. Patients were stratified into sacral-only fixation and spinopelvic fixation groups. Radiographic outcomes included screw loosening, pseudarthrosis, sagittal vertical axis (SVA), and pelvic incidence–lumbar lordosis (PI–LL) mismatch. Clinical outcomes were assessed using the Oswestry Disability Index (ODI) over a standardized two-year follow-up. Results Baseline characteristics were comparable between groups, although anterior lumbar interbody fusion (ALIF) at L5–S1 was performed more frequently in the spinopelvic fixation group (46% vs. 14%, p < 0.001). Sacral-only fixation was associated with higher rates of pseudarthrosis (48% vs. 12%, p < 0.001) and clinically relevant screw loosening (34% vs. 6%, p = 0.004). Spinopelvic fixation was associated with better maintenance of PI–LL mismatch during follow-up, whereas final SVA values were comparable between groups. Both groups demonstrated clinically meaningful functional improvement, although recovery occurred earlier in the spinopelvic fixation cohort. Conclusion Spinopelvic fixation was associated with lower rates of distal mechanical complications and improved maintenance of postoperative spinopelvic alignment following long-segment fusion terminating at the sacrum. Given the retrospective study design and the unequal distribution of ALIF, these findings should be interpreted as hypothesis-generating rather than causal but may support consideration of spinopelvic fixation in patients at increased risk of distal construct failure.

Objectives: Type-D personality, characterized by negative affectivity (NA) and social inhibition (SI), has been associated with adverse outcomes in chronic pain and cardiovascular populations. Evidence in spine outpatient settings remains limited. We aimed to assess the prevalence of Type-D personality and its association with pain, disability, and psychological distress in patients presenting to a university spine outpatient clinic. Methods: This exploratory cross-sectional study included 300 consecutive patients (18-85 years) presenting to a university spine outpatient clinic between 2023 and 2025. Patients completed the Type-D Scale-14 (DS14; Type-D defined as NA ≥10 and SI ≥10), the Hospital Anxiety and Depression Scale (HADS), the Visual Analog Scale for pain (VAS, 0-10), and the Oswestry Disability Index (ODI, 0-100). Demographic and clinical characteristics were recorded. Comparisons between Type-D and non-Type-D patients were performed. Results: The prevalence of Type-D personality was 32.3% (95% CI: 27.0-37.6%). Compared with non-Type-D patients, Type-D patients reported higher pain intensity (VAS: 5.23 vs. 3.88), disability (ODI: 38.6 vs. 31.3), anxiety (HADS-A: 10.0 vs. 6.5), and depression (HADS-D: 8.4 vs. 6.4); all p < 0.01. Between-group differences were clinically relevant, with large effect sizes for pain intensity (VAS; Cohen's d ≈ 1.10) and moderate-to-large effect sizes for functional disability (ODI; Cohen's d ≈ 0.75). Correlation analyses showed moderate to strong associations between Type-D personality traits (negative affectivity and social inhibition) and psychological distress. In stratified analyses, longer pain duration was descriptively associated with greater disability, particularly among patients with Type-D personality. Conclusions: Type-D personality is common in spine outpatient populations and is associated with greater pain, disability, and psychological distress. These findings underscore the relevance of psychosocial factors in spine outpatient care and highlight the need for further longitudinal research to clarify prognostic implications and potential targets for intervention.

Chronic postoperative pain is a common and often insufficiently treated complication that is closely linked with depressive and anxiety symptoms. To investigate whether transcutaneous auricular vagus nerve stimulation (taVNS) reduces postoperative pain and if depressive or anxiety symptoms modulate the treatment effects. In a three-arm, double-blind, randomized controlled trial, 44 patients undergoing joint replacement surgery were allocated to an intervention group (n = 15), sham group (n = 17), or treatment as usual (TAU) control group (n = 12). Assessments were conducted at hospital admission (T0) and before discharge (T1) using the Short-Form McGill Pain Questionnaire (SF-MPQ), the Patient Health Questionnaire‑9 (PHQ-9) and the Generalized Anxiety Disorder 7 (GAD-7). Data were analyzed using mixed-design ANOVA and linear mixed-effects regression models with a Bonferroni correction. There were no significant main or interaction effects of group, time, or group × time on pain intensity (F(2,18) = 0.04, p = 0.959, η2 = 0.003; F(1,18) = 0.89, p = 0.358, η2 = 0.015). The PHQ‑9 scores showed trends for group and time effects (F(2,21) = 5.96, p = 0.009, η2 = 0.322; F(1,21) = 5.06, p = 0.035, η2 = 0.038). The GAD‑7 did not reveal significant effects. Moderation analyses did not indicate any significant effects of depressive or anxiety symptoms on pain change and combined moderation was not significant either. In the present study, taVNS did not reduce postoperative pain and showed no moderating effects of depression or anxiety. Standardization of stimulation parameters, inclusion of psychological and somatic comorbidities and longer high-frequency follow-up periods are needed for future studies.

Interleukin-11 (IL-11) is a member of the IL-6 family of cytokines and possesses both pro- and anti-inflammatory properties. IL-11 activates its target cells via binding to a membrane-bound IL-11R and subsequent formation of a homodimer of the signal-transducing receptor gp130. Thus, the expression pattern of the IL-11R determines which cells can be activated by IL-11. However, knowledge about IL-11 target cells and cells that secrete IL-11 are sparse, and the overall roles of IL-11 in inflammatory diseases are largely unexplored. In this study, we show that high amounts of IL-11 can be detected via ELISA in the synovial fluid of osteoarthritis (OA) patients in comparison to rheumatoid arthritis (RA) patients. Using primary cells and tissue of OA patients, we show that IL-11 is expressed by chondrocytes in cartilage, but not in the synovium. We further identify the cytokine transforming growth factor β 1(TGF-β1) as a potent inducer of IL-11 secretion in both primary chondrocytes and fibroblasts, and TGF-β1 and IL-11 levels correlate significantly in the synovial fluid of OA patients. Using immunohistochemistry, we show that both cartilage and synovium express IL-11R, and the amount of IL-11R is independent of the disease severity. Primary chondrocytes and fibroblasts from OA patients respond to IL-11 stimulation with potent activation of the Jak/STAT3 signaling cascade, suggesting that these cell types are not only the source, but also the targets of IL-11 in OA patients. Our results uncover IL-11 as a potential new target for therapy in OA.

If revision of a unicompartmental knee arthroplasty (UKA) is required, converting it to a total knee arthroplasty (TKA) remains the favored approach. However, worse functional outcomes after revision from UKA to TKA are reported compared to primary TKAs. One potential driver may be a decline in patella height, limiting knee flexion, and increasing patellofemoral stress. Therefore, the aim of this study was to assess whether the patella height changes after revision from UKA to TKA. We retrospectively analyzed 128 aseptic UKA to TKA revisions between 2015 and 2022 at a single medical center. True lateral radiographs were obtained before revision (T1), one week after revision (T2), and at the last follow-up (T3). Two orthopedic surgeons independently measured the modified Insall-Salvati ratio (mISR) at each time point. The mean age was 67 years, 67

BACKGROUND:Massive rotator cuff tears (MRCT) are one of the major challenges in reconstructive shoulder surgery and the therapeutic concepts are still controversial. Using conventional reconstruction techniques rotator cuff re-tear rates still occur up to 52%-94% according to the recent literature. Therefore, superior capsule reconstruction (SCR) using acellular human dermal allografts (AHDG) are currently a frequently applied alternative treatment option for MRCT. Although the functional outcome improves, there is some discrepancy in survival time of the graft. The purpose of this study was to evaluate the structural graft integrity by magnetic resonance imaging (MRI) scans and the functional status of the shoulder early after surgery. MATERIALS AND METHODS:Twenty-nine patients with conventionally irreparable MRCT were treated with an arthroscopic SCR utilized an AHDG (Epiflex, DIZG). Pre- and postoperative MRIs were used to evaluate the rotator cuff and graft configuration. The mean MRI follow-up was 9.8 ± 3.9 (6-21) weeks. The functional status was recorded regarding the Constant Score (CS) and active range of motion. General complications were noted. The clinical follow-up (FU) was 9.4 ± 2.9 (6-17) weeks and 1 year postoperatively at 42.5 ± 5.7 (36-58) weeks. RESULTS:The presence of a total graft failure rate of 59% type 3 according to Mirzayan after SCR with AHDG did not negatively influence the functional outcome during the observation period. There was the main effect of time on all directions of range of motion and all categories of the CS-Score (pain: P < .001, activity: P = .01 and motion: P = .04) except for CS-force value (P = .28) at the first FU and the improvement remained constant until the last FU. There were no significant differences in clinical outcome between the group with graft failure and the group with intact graft at the first and last FU. CONCLUSIONS:The SCR with AHDG in MRCT shows high rate of structural graft failures in early postoperative MRI. However, this does not correlate with the functional outcome in early and mid-term FU. Further studies focusing to elucidate the underlying complex process of in vivo AHDG regeneration and recent developments of biological graft healing and surgery techniques may improve the structural integrity of the SCR construct.

Modular hip joint replacements typically comprise a metal stem, a metal or ceramic ball, a polyethylene or ceramic acetabular cup inlay and a metal shell. Nevertheless, it is evident that this modularity represents a multitude of advantages and disadvantages. Implants retrieved from revision surgery showed evidence of abrasion and corrosion. Increased wear processes may occur. It is possible that these wear mechanisms could be reduced by functionalization of the surface. One potential method for inducing the transformation is through the utilization of a deep rolling process. As the metallic femoral heads are primarily composed of CoCrMo wrought alloy, this study employs a novel deep rolling tool to machine the inner conical bore (inner taper) of the femoral head. The resulting changes in mechanical and physical properties are investigated, as well as their influence on the clamping situation. A considerable enhancement is observed in the mechanical properties and a distinct reduction in surface irregularities, resulting in smoother morphologies after the deep rolling process. Along with the augmented mechanical properties, an improved clamping behavior is also achieved through the augmentation of torsional resistance, which subsequently reduces wear processes in the tapered connection and thus improves the implant.

Objectives: To investigate the association between Type-D personality and pain-related outcomes in patients undergoing spine surgery, and to discuss implications for the management of chronic pain conditions. Methods: A prospective cohort of 200 patients scheduled for elective spine surgery was assessed for Type-D personality using the DS14 scale. Postoperative outcomes including pain intensity (VAS), functional recovery (ODI), complication rates, and patient satisfaction (PSI) were measured preoperatively and at 3, 6, and 12 months. Multivariate regression analyses adjusted for age, sex, surgical approach, comorbidities, and baseline health status. Results: Type-D personality was identified in 30% of patients. These individuals reported significantly higher postoperative pain, slower functional recovery, higher complication rates, and lower overall satisfaction compared to non-Type-D patients. Compared with non-Type-D patients, Type-D patients reported higher pain and slower functional recovery at 12 months (VAS β = 0.34, 95% CI 0.18–0.52, p = 0.004, Cohen’s d = 0.61; ODI β = 0.31, 95% CI 0.12–0.48, p = 0.006, d = 0.58), and lower satisfaction (PSI β = −0.36, 95% CI −0.49 to −0.20, p < 0.001, d = 0.66). Conclusions: Type-D personality is associated with worse postoperative pain and recovery. Preoperative psychological assessment and tailored interventions may improve outcomes. These findings highlight the importance of integrating psychosocial screening into pain management strategies for both spine surgery and chronic pain populations.

BackgroundCalcification of articular tissues is commonly observed in later osteoarthritis (OA) stages and can be caused by basic calcium phosphate (BCP) or calcium pyrophosphate (CPP) crystals. Calcification, particularly CPP deposition, has recently been associated with inflammation and cellular senescence. Investigating this association, we analyzed the concentration of various inflammatory mediators in synovial fluid and synovial membrane of OA patients in relation to calcification and the different crystal types.MethodsSynovial fluid was collected from OA patients during joint replacement surgery. Cytokine concentrations were measured using magnetic bead-based multiplex assay using Luminex® technology. Radiographs were used to determine and grade calcification of the knee joint and involved calcium crystal types were identified via Raman spectroscopy.ResultsSynovial fluid of patients with radiological calcification showed elevated levels of multiple cytokines (IL-10, IL-15, IL-1ra, GM-CSF), chemokines (IL-8, MCP-1, MIP-1b) and growth factors (PDGF-AB/BB, VEGF). Crystal differentiation revealed higher synovial fluid concentrations of IL-15, IL-1ra, IL-10, GM-CSF, PDGF-AB/BB and MIP-1b in patients with CPP- compared to BCP-calcified cartilage.ConclusionWe show an elevated cytokine profile in synovial fluid of patients with radiological calcification that may be linked to CPP depositison in cartilage.

BACKGROUND:The Type D personality ("distressed personality") is characterized by a combination of negative affectivity and social inhibition. While this personality style was originally researched in the context of cardiovascular disease, recent studies also show a significant association with chronic pain disorders, especially back pain. OBJECTIVES:This narrative review examines the current state of knowledge on the relationship between type D personality and back pain. The aim is to analyze possible psychological, behavioral, and biological mechanisms and to derive clinical implications for orthopedic pain therapy. MATERIALS AND METHODS:A selective literature search was conducted in the PubMed, PsycINFO and Google Scholar databases. Original studies, systematic reviews and meta-analyses from the last 20 years focusing on psychosomatic aspects of chronic back pain were included. RESULTS:Several studies show that individuals with Type D characteristics have an increased risk of developing and chronicizing back pain. Possible mediating mechanisms include maladaptive stress processing, somatisation, reduced social support and changes in neuroendocrine and inflammatory processes. CONCLUSIONS:Type D personality is a relevant psychosocial risk factor in the development and persistence of chronic back pain. Early detection may contribute to improving multidisciplinary therapeutic approaches.