Bone & Joint Research最新文献

Aims: The aim of this study was to investigate which patient- and fracture-related factors predict functional outcome at two years in patients aged 60 years or older with a proximal humerus fracture, and to assess the possible evidence in favour of treatment effect heterogeneity in these patients.

Methods: This was a secondary analysis of a prior randomized controlled trial. We included patients from a Nordic multicentre trial including two trial cohorts (two-part and multipart): 88 patients with a two-part fracture (nonoperative vs locking plate), and 160 patients with a multipart fracture (nonoperative vs locking plate vs hemiarthroplasty) recruited between February 2011 and December 2019. The outcomes were Disabilities of Arm, Shoulder and Hand (DASH) questionnaire score, Oxford Shoulder Score (OSS), and Constant-Murley score (CS) at two years. Ordinary least squares regression was used to estimate 24 months of functional outcomes. We used the methodology described in the Predictive Approaches to Treatment effect Heterogeneity (PATH) statement for the assessment of treatment effect heterogeneity.

Results: A total of 248 patients were included in the trials. Dizziness frequency was the most important predictor for DASH and OSS at 24 months. Dominance of the injured arm was the most important predictor for Constant score. R², describing the variation explained by the baseline variables, showed moderate model fit for all outcomes, i.e. DASH (0.395), OSS (0.363), and CS (0.387). When operative treatments were compared with nonoperative treatments, the interactions between predicted outcome and treatment assignment were small and had high uncertainty, implying a lack of heterogeneous treatment effect.

Conclusion: We found that dizziness at baseline is the strongest predictor for DASH and OSS at 24 months. Our results showed that patient selection, based on the covariates available to us, does not seem to be a credible possibility in older patients with proximal humerus fractures, and thus nonoperative treatment should remain the gold standard.

Aims: Tibial plateau fractures (TPFs) commonly occur in older osteoporotic individuals and pose significant challenges during acute total knee arthroplasty (TKA). This study aimed to evaluate the biomechanical performance of asymmetric metaphyseal cones in managing lateral TPFs during acute TKA.

Methods: A finite element model was developed using a generic size 5 tibia geometry with an integrated asymmetric metaphyseal cone system. Various lateral TPF patterns were systematically simulated through 12 uncontained defect configurations, quantified by the unsupported surface area ratios of the cone (R_u). Four physiological loading conditions (standing up, walking, knee bending, and stair descending) were analyzed under standardized boundary constraints. Bone-implant interface micromotions were assessed against an osseointegration threshold (150 μm), while cancellous bone strains were evaluated against yield criteria (greater than 0.5% for tension and less than -0.7% for compression).

Results: The implant system demonstrated stable biomechanical performance across all loading conditions when R_u ≤ 44%, with micromotions remaining below 50 μm. Maximum interface micromotions of 82 µm occurred during stair descending at R_u = 56%, remaining substantially below the osseointegration threshold. Significant increases in micromotions and in the volume of bone exceeding the strain criteria occurred for R_u > 44%. The posterolateral region exhibited the highest micromotion and strain concentrations, indicating a critical zone for biomechanical stability.

Conclusion: Asymmetric metaphyseal cones provide effective stabilization for lateral uncontained defects, managing micromotions and bone strains within clinically safe limits. The recommended maximum defect size for cone treatment is an unsupported area ratio R_u = 44%. These findings suggest that asymmetric metaphyseal cones present a promising option for addressing severe lateral TPFs during acute TKA.

Aims: After total hip arthroplasty (THA), dual-energy x-ray absorptiometry (DXA) is used as necessary to assess the bone mineral density (BMD) in the Gruen zones around the femoral stem implants. Although periprosthetic BMD may serve as a potential indicator for evaluating stress adaptive remodelling and stem fixation, several factors can introduce measurement errors. Therefore, an automated method was applied using quantitative CT, verified for the total hip with correlation coefficient > 0.9, for BMD assessment in the Gruen zones.

Methods: This was a retrospective analysis of 71 hips from 58 participants (9 male and 49 female) who underwent THA using the same taper-wedge type stem. Preoperative and postoperative CT scans were acquired alongside DXA measurements of the Gruen zones. A deep-learning method was used to measure BMD in the Gruen zones from preoperative CT images by embedding the stem position information acquired from postoperative CT images through iterative closest point registration. CT images were rotated to the neutral position and were projected anteroposteriorly to generate a digitally reconstructed radiograph to measure the BMD at each zone (CT-aBMD). Correlations between CT-aBMD and DXA measurements were assessed for each zone.

Results: The correlations between CT-aBMD and DXA measurements for zones 1 to 7 were 0.924, 0.783, 0.817, 0.921, 0.731, 0.847, and 0.677, respectively (p < 0.001 for all).

Conclusion: Our results based on CT analysis suggest that DXA is generally reliable for assessing BMD in the Gruen zones. However, caution may be advised for zones 5 and 7 because of limited correlations. As zone 7 plays a crucial role in stem fixation, during longitudinal evaluation of post-THA stress adaptive remodelling, we recommend ensuring cautious interpretation and consistent BMD measurements using the image attached to the DXA report. It is imperative to calculate the least significant change for accurate BMD evaluation.

Aims: Discogenic pain due to intervertebral disc (IVD) degeneration contributes substantially towards low back pain (LBP). This study aims to develop novel and non-invasive diagnostic tools by directly comparing the quantitative results of the normal and degenerated osteochondral endplates obtained using simultaneous ¹⁸F-NaF PET/MRI.

Methods: We prospectively enrolled 22 participants with chronic lower back pain from August 2022 to November 2023. We classified all 110 lumbar IVDs (L1/2-L5/S1 in 22 people) into 75 normal IVDs and 35 degenerative IVDs. The T2 relaxation times in the cartilaginous endplate on MRI (T2rt-CEP-MR) and normalized subchondral bone on positron emission tomography (PET) images (SUVmax-SB-PET) of all 110 lumbar IVDs were recorded. To analyze the relationship between the cartilaginous endplate and neighbouring subchondral bone, we employed Pearson correlation coefficient and generalized estimating equation (GEE) models to examine the T2rt-CEP-MR and SUVmax-SB-PET results in normal and degenerative IVDs.

Results: We observed lower T2rt-CEP-MR in the middle location of the disc (p = 0.003) and higher SUVmax-SB-PET in the anterior, middle, and posterior locations of the disc (p = 0.030, p = 0.006, and p < 0.001, respectively) in degenerative IVDs. Regarding the association between the T2rt-CEP-MR of discs and the SUVmax-SB-PET of the neighbouring subchondral bone, we observed a significant correlation (r = 0.211 to 0.328, p < 0.001) in all locations of normal IVDs. Additionally, a significant correlation was observed in the anterior and middle locations of the degenerative IVDs, and a marginally significant correlation was observed in the posterior region of the degenerative IVDs (r = 0.159, p = 0.060).

Conclusion: Simultaneous ¹⁸F-NaF PET/MRI is a novel and reliable technique for evaluating the osteochondral endplate. The differences in quantitative results could help clinicians to establish an impression of discogenic pain. A spatial relationship exists between the biochemical changes within discs and subchondral bone metabolism.

Femoroacetabular impingement (FAI) is caused by abnormal contact between the femur and acetabulum, resulting in pain, limited motion, and early osteoarthritis. Existing imaging techniques for diagnosing FAI face considerable challenges. Radiomics involves the quantitative extraction and analysis of imaging features using advanced algorithms, often combined with machine learning (ML), to enhance diagnostic and prognostic precision. When integrated with ML, radiomics can identify patterns beyond conventional imaging measurements, potentially enabling automated, precise, and reproducible assessment of hip morphology and pathology. Early studies demonstrate its potential to differentiate between normal, symptomatic, and asymptomatic cam-type hips. However, challenges persist, including the standardization of imaging protocols, feature selection, access to large datasets, and the explainability of models. This review summarizes the state of the art in radiomics for FAI and highlights its future applications.

Aims: Cystic lesions are strongly associated with the pathogenesis and selection of treatment strategies in osteoarthritis (OA) and osteonecrosis of the femoral head (ONFH). However, the differences in cystic lesions arising from these two diseases are not fully understood. This study aimed to delineate the variations in cyst characteristics in the femoral heads of patients with OA and ONFH.

Methods: A total of 45 patients with OA and 105 patients with ONFH who underwent total hip arthroplasty (THA) between September 2014 and December 2021 were recruited in the study. The 3D distribution, microstructure, and histological characteristics of cystic lesions were comprehensively analyzed. Comparative assessments of the microstructural, histomorphometric, and histopathological properties of cystic lesions between OA and ONFH were performed, using micro-CT, decalcified and undecalcified bone histomorphology, and scanning electron microscopy (SEM).

Results: In comparison to ONFH, cystic lesions in OA exhibited a smaller volume and a denser distribution. Despite a common prevalence in the anterior hemisphere in both conditions, ONFH cysts were predominantly located laterally, whereas OA cysts were found mainly medially. In OA, the trabecular bone surrounding the cystic lesions exhibited a more sclerotic microarchitecture, with an increase in bone formation and a decrease in bone resorption at the remodelling level. Histologically, cystic lesions in ONFH demonstrated a higher degree of angiogenesis compared to those in OA.

Conclusion: While cystic lesions in both OA and ONFH were predominantly located in the anterior hemisphere, they exhibited different distribution and involvement characteristics, microstructure and bone remodelling properties, as well as histopathological features.

Aims: Mitochondrial transplantation has been proposed as a potential treatment for injured ligament tissue. This study aimed to investigate the relationship between the time from injury to surgery and the activity of injured anterior cruciate ligament (ACL) cells. Additionally, we evaluated the effectiveness of mitochondrial transplantation in chronically injured ACL cells and in an in vivo ACL partial tear animal model.

Methods: First, ACL injured tissue from rabbits (n = 6 for each timepoint) was harvested at two (acute), four (subacute), and eight (chronic) weeks following ACL transection. We investigated cell proliferation, migration capability, and the expression of collagen synthesis, vascular endothelial growth factor (VEGF), and transforming growth factor-β (TGF-β) genes in injured ACL cells at different injury timepoints. Second, we isolated mitochondria from human adipose-derived stem cells (hADSCs) and transplanted them into the ACL cells. Lastly, we evaluated the in vivo effects of hADSCs-mitochondrial transplantation in a rabbit knee model with partial ACL tear.

Results: After injury, the highest cell activity was observed at four weeks. Immunohistochemical staining showed that hADSCs-mitochondria were taken up by the eight-week injured ACL cells, leading to subsequent improvements in cell viability, migration capability, and collagen synthesis, and VEGF gene expression which were superior to those of untreated cells. At eight weeks, treated injured ACL cells achieved cell proliferation and collagen type I, type III, and VEGF expression levels comparable to those of four-week injured cells. In the in vivo study, enhanced collagen synthesis was observed in the histological analysis following hADSCs-mitochondrial transplantation.

Conclusion: The optimal timing of ACL reconstruction is four to six weeks after injury due to peak cell activity. Mitochondrial transplantation improves the activity of chronically injured ACL cells and enhances collagen synthesis in ACL partial tears, highlighting its potential as a treatment for improving their regenerative capability.

Aims: The reconstruction of complex defects involving various tissues still presents a challenge for reconstructive surgery and makes a combined flap indispensable. The mediodistal femur region (MDFR), which is supplied by the descending genicular artery (DGA), represents a unique donor site for harvesting combined flaps. This study analyzes the vascular anatomy of this region and the possible types of combined flaps.

Methods: Within this analysis, the vascular supply of the DGA in a total of 35 lower limbs was investigated, having been embalmed with the Walter Thiel technique in order to enable lifelike conditions.

Results: The DGA was detectable in 100% (n = 35) of all instances. The artery divided into three branches in 48.57% (n = 17) of cases and two branches in the remaining cases. In 40% (n = 14) of cases we found a saphenous artery (SA) and a musculoarticular branch (MAB), in 8.57% (n = 3) an articular branch (AB) and a muscular branch (MB), and in 2.86% (n = 1) a SA and a MB. Usage of DGA branches enabled corticoperiosteal, corticocancellous, osteochondral, or osteocutaneous flaps in 100% (n = 35) of our cases, and myocorticoperiostal, osteomyotendinous, osteomyotendocutanous, or osteotendofasciocutaneous flaps in 97.14% (n = 34). Vascular supply of skin flaps was feasible via the SA in 100% (n = 35) of cases or via dermal branches of the AB in 37.14% (n = 13).

Conclusion: The multitissue, distal-mediofemoral region, supplied by the DGA and its branches, offers an optimal donor site with reliable vascularization, enabling the harvesting of combined flaps.

Aims: Intervertebral disc degeneration (IDD) and sagittal-oriented articular processes can restrict motility and increase stiffness of the motion segment, potentially causing compensatory stress and higher motility in adjacent segments. It is unclear if these factors trigger IDD progression in adjacent segments. This study aimed to elucidate this using functional MRI, and identify biomechanical mechanisms with a validated numerical model.

Methods: Clinical data from 95 patients were retrospectively collected from January 2022 to April 2023. Disc collapse and fibrosis were assessed by disc height ratio and fractional anisotropy (FA) values in the L4-L5 segment. The orientation of articular facet processes in L4-L5 was examined. Annulus fibrosus integrity was investigated using diffusion tensor fibre tractography in cranial (L3-L4) and caudal (L5-S1) segments. Statistical analyses determined differences between patients with and without annulus tears, and regression analyses identified predictors of annulus tears. Numerical models of L3-S1 motion segment were developed, incorporating variations in disc collapse, fibrosis, and facet orientation angles in L4-L5. Stress distribution on cranial and caudal discs was calculated under various loading conditions.

Results: Compared to patients with intact annulus at the cranial segment (L3-L4), those with annulus tears show reduced facet orientation angles and disc height ratios, and elevated FA values. These parameters are independent risk factors for cranial annulus tears, not observed on the caudal side. Models with sagittal-oriented articular processes (facet orientation = 35°), disc collapse, and fibrosis show higher stress on the cranial disc, particularly within the annulus, compared to models with coronal-oriented processes (facet orientation = 65°) and healthy discs.

Conclusion: Sagittal orientation of articular processes and IDD phenotypes may increase the risk of annulus tears in the cranial adjacent segment by compromising the biomechanical environment. This offers a novel perspective for understanding biomechanical interactions in adjacent segments during IDD progression.