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(1) Background: This report aims to illustrate the development, progression, diagnosis, and treatment of chronically present articular surface lesions. (2) Methods: In this report, two patients are described from the point of the initial presentation of symptoms to surgical consultation based on radiologic findings. These patients underwent corrective surgery in the form of mosaicplasty to repair lesions present on the articular surface and the underlying subchondral bone. (3) Discussion: Diagnosing juvenile OCD remains challenging due to its variable clinical presentation and minute radiologic discoveries. X-rays are useful; however, the gold standard remains arthroscopy, which can be both diagnostic and therapeutic. Future prospects include the use of novel sonographic methods and the use of artificial intelligence within the given modalities. (4) Conclusions: The detailed imaging provided by MRI, combined with the insights from X-rays and potentially other modalities, allows for a nuanced understanding of this disease. This comprehensive approach ensures that treatment decisions are well-informed, optimising outcomes for young patients with this condition. [ABSTRACT FROM AUTHOR]

The article focuses on the clinicoradiological outcomes of arthroscopic-assisted reduction and internal fixation of tibial plateau fractures. Topics include the surgical challenges and advantages of using arthroscopy for precise fracture reduction and stable fixation; the clinical and radiological outcomes based on the modified Rasmussen criteria; and the potential complications and limitations of this surgical technique.

Copyright of Equine Veterinary Journal is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The aim of this study was to investigate the radiological outcomes of proximal closing metacarpal extension osteotomies using patient-specific guides and instruments (PSI) in early-stage trapeziometacarpal osteoarthritis to gain further insight into the joint loading surface and the benefits of the procedure. Methods: In a prospective observational study, nine patients were included between 11/2020 and 12/2021, undergoing a total of ten proximal metacarpal extension osteotomies for basal thumb osteoarthritis. Computer-assisted surgical planning was performed using computed tomography (CT) and three-dimensional (3D) segmentation, allowing the fabrication of 3D-printed PSIs for surgical treatment. Inclusion criteria were a 1-year follow-up by CT to assess postoperative correction of the positional shift of the first metacarpal (MC1) and the location of peak loads compared with the preoperative situation. Results: Radiographic analysis of the peak loading zone revealed a mean displacement on the articular surface of the trapezius of 0.4 mm ± 1.4 mm to radial and 0.1 mm ± 1.2 mm to palmar, and on the articular surface of the MC1 of 0.4 mm ± 1.4 mm to radial and 0.1 mm ± 1.2 mm to dorsal. Conclusion: There were trends indicating that a flatter pressure distribution and a dorsal shift of the peak loading zone may contribute to an improvement in subjective pain and patient satisfaction associated with this surgical procedure. The non-significant radiological results and the minor dorsal-radial shifts in our small study group limit a firm conclusion. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Objectives: Synovial joints in human limbs strike a balance between mobility, stability, and articular fit, yet little is known about how these conflicting demands pattern intraspecific variation in articular shape. In this study, we use geometric morphometrics to establish the apportionment and magnitude of morphological variance of the articular surfaces of the human shoulder, elbow, hip, and knee. We hypothesize that variances will be comparable between articulating surfaces within a joint and will be larger in joints with smaller ranges of motion, given their plurality of functional demands. Materials and Methods: Three‐dimensional landmarks were taken on the articular surfaces of the glenohumeral, humeroulnar, acetabulofemoral, and tibiofemoral joints from CT scans of 200 skeletons from the University of Tennessee Donated Skeletal Collection (84 females, 116 males). Root mean‐squared distances between articulations calculated from Procrustes shape coordinates were used to determine variance distributions. Results: We found no difference in variances for each articular surface between the sexes or between left and right articular surfaces. A high range of motion is associated with greater morphological variance; however, this pattern is largely driven by the concave articular surfaces of each joint, which consistently exhibit statistically greater variance than their convex counterparts. Discussion: The striking pattern of differential variance between articulating morphologies points to potential disparities in development between them. Consistently higher variance in concave surfaces may relate to chondral modeling theory for the formation of joints. Establishing intraspecific morphological variance patterns is a first step in understanding coordinated evolution among articular features. [ABSTRACT FROM AUTHOR]

Objectives: Limb synovial joints exhibit complex shapes that must accommodate often‐antagonistic demands of function, mobility, and stability. These demands presumably dictate coordination among joint articular shapes, but the structure of morphological covariance within and among joints is unknown. This study analyzes the human shoulder, elbow, hip, and knee to determine how articular covariance is structured in relation to joint structure, accessory cartilage, and function. Materials and Methods: Surface models were created from the CT scans of 200 modern skeletons from the University of Tennessee Donated Skeletal Collection. Three‐dimensional landmarks were collected on the shoulder, elbow, hip, and knee joints. Two‐block partial least squares were conducted to determine associations between surfaces of conarticular shapes, functionally analogous articulations, and articulations belonging to the same bone. Results: Except for the components of the shoulder, all conarticular pairs exhibit covariance, though the strength of these relationships appears unrelated to the amount of accessory cartilage in the joint. Only the analogous articulations of the humerus and femur exhibit significant covariance, but it is unlikely that this pattern is due to function alone. Stronger covariance within the lower limb than the upper limb is consistent broader primate patterns of within‐limb integration. Discussion: With the exception of the elbow, complementary joint function does not appear to promote strong covariance between articulations. Analogous humeral and femoral surfaces are also serially homologous, which may result in the articular associations observed between these bones. Broadly, these patterns highlight the indirect relationship between joint congruence and covariance. [ABSTRACT FROM AUTHOR]

Articular surface irregularities are often observed in collapsed femoral heads with osteonecrosis, while the effects of the degree of collapse on the articular surface are poorly understood. We first macroscopically assessed the articular surface irregularities on 2‐mm coronal slices obtained using high‐resolution microcomputed tomography of 76 surgically resected femoral heads with osteonecrosis. These irregularities were observed in 68/76 femoral heads, mainly at the lateral boundary of the necrotic region. The mean degree of collapse was significantly larger for femoral heads with articular surface irregularities than for those without (p < 0.0001). Receiver operating characteristic analysis showed that the cutoff value for the degree of collapse in femoral heads with articular surface irregularities at the lateral boundary was 1.1 mm. Next, for femoral heads with <3‐mm collapse (n = 28), articular surface irregularities were quantitatively assessed based on the number of automatically counted negative curvature points. Quantitative evaluation showed that the degree of collapse was positively correlated with the presence of articular surface irregularities (r = 0.95, p < 0.0001). Histological examination of articular cartilage above the necrotic region (n = 8) revealed cell necrosis in the calcified layer and abnormal cellular arrangement in the deep and middle layers. In conclusion, articular surface irregularities of the necrotic femoral head depended on the degree of collapse, and articular cartilage was already altered even in the absence of macroscopically determined gross irregularities. [ABSTRACT FROM AUTHOR]

The treatment of medial tibial plateau fractures can be challenging due to poor exposure of the articular surface. Therefore, a medial epicondyle osteotomy may be needed. Current methods describe osteotomy of the medial femoral epicondyle. However, this method requires additional detachment of the medial meniscus in order to ensure proper visualization. The aim of this study is to present a new technique using distal osteotomy of the superficial medial collateral ligament and to analyze the area of the exposed articular surface area. On each of eight fresh-frozen human cadaveric knees (mean age: 79.4 ± 9.4 years), an osteotomy and proximal reflection of the distal insertion of the superficial medial collateral ligament combined with a submeniscal arthrotomy was performed, followed by a medial epicondyle osteotomy. Using a three-dimensional measurement arm (Absolute Arm 8320-7, Hexagon Metrology GmbH), the exposed area was analyzed and compared to the entire medial articular surface using ANOVA (p < 0.05). Through the medial epicondyle osteotomy, 39.9 ± 9.7% of the anteromedial articular surface was seen. This area was significantly smaller compared to the osteotomy of the distal insertion of the superficial collateral ligament with an exposed articular surface of 77.2 ± 16.9% (p = 0.004). Thus, the distal osteotomy exposed 37.3% more of the articular surface compared to the medial epicondyle osteotomy. None of these techniques were able to adequately expose the posteromedial- and medial-most aspects of the tibial plateau. A distal superficial collateral ligament osteotomy may be superior to a medial epicondyle osteotomy when an extension of the anteromedial approach to the tibial plateau is required. A distal superficial medial collateral ligament osteotomy combines the advantages of better exposure of the medial articular surface with preservation of the blood supply to the medial meniscus. However, surgeons should carefully consider whether such an extended approach is necessary, as it significantly increases invasiveness. [ABSTRACT FROM AUTHOR]

Background: Hemi-hamate arthroplasty is one of the treatment options for dorsal proximal interphalangeal joint fracture dislocation. Many studies reported favorable outcomes. However, some long term studies demonstrated the degenerative change of PIP joint. The articular mismatch of the hemi-hamate autograft might play an important role of this complication. Methods: We studied the anatomy of distal articular surface of the hamate bone in embalmed hamate bones. The anatomy of distal articular surface and dimensions of the hamate bone were measured and recorded. Results: Seventy hamate bones were dissected out from embalmed cadavers and included in this study. The mean angle of the 4th metacarpal articulation was 85.54 degrees (SD = 3.53) and mean angle of the 5th metacarpal articulation was 95.51 degrees (SD = 3.57). The inter-articular ridge was approximately 5 degrees radial inclination. Conclusions: The inter-articular ridge of distal articular surface was approximately 5 degrees radial inclination. In order to minimize the graft mismatch, we recommend making the bone cut with the saw blade tilted to radial side 5 degrees to achieve better alignment of inter-articular ridge of the graft. [ABSTRACT FROM AUTHOR]

The free surface of the articular cartilage must withstand compressive and shearing forces, maintain a low friction coefficient and allow oxygen and metabolites to reach the underlying matrix. In many ways it is critical to the physiology of the whole tissue and its disruption always involves deep pathological alterations and loss of the joint integrity. Being very difficult to image with section‐based conventional techniques, it was often described by previous research in conflicting terms or entirely overlooked. High‐magnification face‐on observations with high resolution scanning electron microscopy and with scanning probe microscopy revealed a very thin, delicate superficial layer rich in glycoconjugates, which may explain the very low friction coefficient of the tissue but which was very easily altered and/or dissolved in the preparation. Beneath this superficial sheet lies a thicker coat of thin, highly uniform, slightly wavy collagen fibrils lying parallel to the surface and mutually interconnected by a huge number of interfibrillar glycosaminoglycan bridges. These bridges and the collagen fibrils form an extended reticular structure able to redistribute tensile and compressive stress across a larger area of the surface and hence a greater volume of tissue. [ABSTRACT FROM AUTHOR]

Background: An inflamed and thickened medial patellar plica (MPP) caused by repeated mechanical irritation from trauma or overuse leads to impingement between the anterior medial femoral condyle and the medial articular facet of the patella and produces pain or clicking, which is known as MPP syndrome. In patients with MPP syndrome, cartilage damage may occur depending on the shape of the MPP and the duration of the impingement.Case Presentation: Preoperative magnetic resonance imaging in a 17-year-old male patient with MPP syndrome showed a hypertrophic MPP along with an abnormal notch in the articular surface of the medial femoral condyle. We considered that the impinged hypertrophic plica between the anterior medial femoral condyle and the medial articular facet of the patella resulted in cartilage damage on the articular surface of the medial femoral condyle. However, during arthroscopic surgery, we found that the cartilage of the notch, which was located beneath the MPP, was completely intact. We concluded that this abnormal notch had developed gradually in the MPP without cartilage damage.Conclusions: Surgeons should be mindful that acquired plica-induced notches in the articular surface of the medial femoral condyle can present in patients with MPP syndrome. [ABSTRACT FROM AUTHOR]

Osteochondral defects are often symptomatic and lead to deranged joint function. The spontaneous healing capacity of osteochondral defects is limited. In this case study, use of an acellular scaffold capable of induction of mesenchymal stem-cell migration is described. This scaffold was used on an Outerbridge grade IV medical condylar defect measuring ~2 cm2. At 24 mo follow-up, the articular surface appeared restored by MRI, and the patient returned to sports. [ABSTRACT FROM AUTHOR]

Purpose: Anatomic reduction in tibial plateau fractures remains to be demanding. For further visualisation of and approach to the joint surface an extended lateral approach using a lateral femoral epicondyle osteotomy and subluxation of the lateral meniscus was recently described. First clinical and radiographic mid-term results of this technique are presented in this feasibility study. Method: Ten complex tibial plateau fractures treated with extended lateral approach and lateral meniscal subluxation were prospectively analysed. Clinical and radiographic results were objectified according to the Rasmussen scores. Results: After a median follow-up of 8.6 (IQR 4.3) months good to excellent clinical and radiographic results were noted. The clinical Rasmussen Score showed a median of 25 (IQR 2.8) and radiographic a median of 17 (IQR 2.0) points. Conclusion: Good to excellent clinical and radiological scores were obtained after using an extended lateral approach with lateral femoral epicondyle osteotomy and central meniscus subluxation. No approach specific complications could be observed. [ABSTRACT FROM AUTHOR]

Background: The tibial slope plays an important role in knee surgery. However, standard radiographic measurement techniques have a low reproducibility and do not allow differentiation between medial and lateral articular surfaces. Despite availability of three-dimensional imaging, so far, no real 3D measurement technique was introduced and compared to radiographic measurement, which were the purposes of this study.Methods: Computed tomography scans of 54 knees in 51 patients (41 males and 10 females) with a mean age of 46 years (range 22-67 years) were included. A novel 3D measurement technique was applied by two readers to measure the tibial slope of medial and lateral tibial plateau and rim. A statistical analysis was conducted to determine the intraclass correlation coefficient (ICC) for the new technique and compare it to a standard radiographic measurement.Results: The mean 3D tibial slope for the medial plateau and rim was 7.4° and 7.6°, for the lateral plateau and rim 7.5° and 8.1°, respectively. The mean radiographic slope was 6.0°. Statistical analysis showed an ICC between both readers of 0.909, 0.987, 0.918, 0.893, for the 3D measurement of medial plateau, medial rim, lateral plateau and lateral rim, respectively, whereas the radiographic technique showed an ICC of 0.733.Conclusions: The proposed novel measurement technique shows a high intraclass agreement and offers an applicable opportunity to assess the tibial slope three-dimensionally. Furthermore, the medial and lateral articular surfaces can be measured separately and one can differentiate the slope from the plateau and from the rim. As three-dimensional planning becomes successively more important, our measurement technique might deliver a useful supplement to the standard radiographic assessment in slope related knee surgery.Level Of Evidence: Level III, diagnostic study. [ABSTRACT FROM AUTHOR]

Objective: To determine the visible size of the distal humeral articular surface by using a novel combined medial‐lateral approach as an alternative method of surgical treatment for intra‐articular distal humeral fractures. Methods: In this anatomical study, 12 adult fresh‐frozen cadaveric elbows were randomly divided into a medial‐lateral group and an olecranon osteotomy group, with 6 in each group. In the medial‐lateral group, a medial approach was first used, and then a lateral approach. The sizes of the distal humeral articular surface exposed by each incision and the joined size were measured and calculated. In the olecranon osteotomy group, a posterior olecranon osteotomy approach was applied, and the maximal visible sizes of the articular surface were marked and calculated. Ratios of the maximal sizes of the distal humeral articular surface of the two approaches were compared. Results: In the medial‐lateral group, the medial approach could expose 2/5 of the medial trochlea and 1/3 of the capitellum, while the mean visible size of the distal humeral articular surface was 6.8 cm2, 34.8% of the entire surface; the lateral approach can expose 3/7 of the capitellum and 1/4 of the medial trochlea, while the mean visible size of the distal humeral articular surface was 6.7 cm2, 33.9% of the whole surface; for the combined medial‐lateral approach, the mean scope exposed of the medial and lateral visible articular surface was 38.2% and 43.1%, respectively. Meanwhile, in the olecranon osteotomy group, the posterior olecranon osteotomy was found to expose most of the posterior distal humeral articular surface, except for 1/3 of the anterior trochlea and 1/4 of the anterior capitellum, and the visible range of articular surface was 65.3%. The combined medial‐lateral approach exposed 9.2 cm2 in total, 46.9% of the whole distal humeral articular surface, which averaged 19.6 cm2. However, the visible size of the distal humeral articular surface for the olecranon osteotomy approach was 13.7 cm2, 63.1% of the entire distal humeral articular surface, which averaged 21.3 cm2. There was a significant difference observed between the medial‐lateral group (46.9%) and the olecranon osteotomy group (63.1%) for the maximal visible size of the distal humeral articular surface (t = 7.201, P = 0.001). Conclusions: The combined medial‐lateral approach can expose 46.9% of the distal humeral articular surface, concentrating on the anterior part, so it can be recommended to treat intra‐articular fractures with a simple pattern in the posterior with the anterior side of the distal humerus less comminuted. [ABSTRACT FROM AUTHOR]

Introduction: Primary goals of the study were to present the mid -- to long - term survivorship and clinical, radiological and metal serological results of the first stem -- navigated ASR™ resurfacing at our clinic. Secondary goals were to determine the influence of stem -- navigation on the outcome and risk factors for revision in our cohort. Methods: From Mai 2006 to Mai 2009 46 ASR™ resurfacing hip systems have been implanted in 43 patients with a median age of 55 years. At final follow -- up (33 implants with a mean follow --up of 89,6 months) guidelines were followed and HHS and HOOS were completed. Inclination, NSA and SSA were measured on radiographs and signs of loosening were graded. Risk factors for revision were compared in the non -- revision and revision group. Results: Mean cumulative survival of the prosthesis after 99,9 Months was 81,8%. At final follow -- up 8 revisions were performed. Median HHS was 97, HOOS was 87,2. Four prostheses showed signs of loosening and nine heterotopic ossifications. All shaft components, except one, were placed in minimal valgus position to avoid risk for fracture. Age and diameter of the femoral component were significantly different between the non -- revision and revision group. Discussion: Survivorship is comparable to numbers found in other studies. Patients with complete final follow -- up in general had good objective and subjective scores and few signs of loosening in the radiological follow -- up. Navigation might have a positive effect on reduction of risk for fracture. Age and diameter of the femoral component seem to influence the outcome. [ABSTRACT FROM AUTHOR]

Purpose: The existing literature on lateral atlantoaxial joints is predominantly on bony facets and is unable to explain various C1-2 motions observed. Geometric morphometry of facets would help us in understanding the role of cartilages in C1-2 biomechanics/kinematics. Objective: Anthropometric measurements (bone and cartilage) of the atlantoaxial joint and to assess the role of cartilages in joint biomechanics. Materials and Methods: The authors studied 10 cadaveric atlantoaxial lateral joints with the articular cartilage in situ and after removing it, using three-dimensional laser scanner. The data were compared using geometric morphometry with emphasis on surface contours of articulating surfaces. Results: The bony inferior articular facet of atlas is concave in both sagittal and coronal plane. The bony superior articular facet of axis is convex in sagittal plane and is concave (laterally) and convex medially in the coronal plane. The bony articulating surfaces were nonconcordant. The articular cartilages of both C1 and C2 are biconvex in both planes and are thicker than the concavities of bony articulating surfaces. Conclusion: The biconvex structure of cartilage converts the surface morphology of C1-C2 bony facets from concave on concavo-convex to convex on convex. This reduces the contact point making the six degrees of freedom of motion possible and also makes the joint gyroscopic. [ABSTRACT FROM AUTHOR]

Reasons for performing study Changes in subchondral bone density, induced by the repetitive cyclical loading of exercise, may potentiate fatigue damage and the risk of fracture. Objectives To use computed tomography ( CT) to characterise bone density patterns at the articular surface of the third metacarpal bone in racehorses with and without lateral condylar fractures. Study Design Case control Methods Computed tomographic images of the distal articulating surface of the third metacarpal bone were obtained from Thoroughbred racehorses subjected to euthanasia in the UK. Third metacarpal bones were divided into 3 groups based on lateral condyle status; fractured ( FX, n = 42), nonfractured contralateral condyle ( NFX, n = 42) and control condyles from horses subjected to euthanasia for reasons unrelated to the third metacarpal bone (control, n = 94). Colour CT images were generated whereby each colour represented a range of pixel values and thus a relative range of bone density. A density value was calculated qualitatively by estimating the percentage of each colour within a specific region. Subchondral bone density was assessed in 6 regions from dorsal to palmar and 1 mm medial and lateral to the centre of the lateral parasagittal groove in NFX and control condyles and 1 mm medial and lateral to the fracture in FX condyles. Results Bone density was significantly higher in the FX and NFX condyles compared with control condyles for all 6 regions. A significantly higher bone density was observed in FX condyles relative to NFX condyles in the lateral middle and lateral palmar regions. Fractured condyles had increased heterogeneity in density among the 6 regions of interest compared with control and NFX condyles. Conclusions Adjacent to the fracture, a focal increase in bone density and increased heterogeneity of density were characteristic of limbs with lateral condylar fractures compared with control and NFX condyles. These differences may represent pathological changes in bone density that increase the risk for lateral condylar fractures in racehorses. [ABSTRACT FROM AUTHOR]

Purpose: In orthopedic surgeries, it is important to avoid intra-articular implant placements, which increase revision rates and the risk of arthritis. In order to support the intraoperative assessment and correction of surgical implants, we present an automatic detection approach using cone-beam computed tomography (CBCT). Methods: Multiple active shape models (ASM) with specified articular surface regions are used to isolate the joint spaces. Fast and easy-to-implement methods are integrated in the ASM segmentation to optimize the robustness and accuracy for intraoperative application. A cylinder detection method is applied to determine metal implants. Intersections between articular surfaces and cylinders are detected and used to find intra-articular collisions. Results: Segmentations of two calcaneal articular surfaces were evaluated on 50 patient images and have shown average surface distance errors of 0.59 and 0.46 mm, respectively. The proposed model-independent segmentation at the specified articular surface regions allowed to significantly decrease the error by 22 and 25 % on average. The method was able to compensate suboptimal initializations for translations of up to 16 mm and rotations of up to 21 $$^{\circ }$$ . In a human cadaver test, articular perforations could be localized with an accuracy of 0.80 mm on average. Conclusions: A concept for automatic intraoperative detection of intra-articular implants in CBCT images was presented. The results show a reliable segmentation of articular surfaces in retrospective patient data and an accurate localization of misplaced implants in artificially created human cadaver test cases. [ABSTRACT FROM AUTHOR]

During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined. [ABSTRACT FROM AUTHOR]

Purpose: The assessment of intra-operatively acquired volumetric data is a difficult and often time-consuming task, which demands a new set of skills from the surgeons. In the case of orthopedic surgeries such as the treatment of calcaneal fractures, the correctness of the reduction of the bone fragments can be verified with the help of C-arm CT volumetric images. For an accurate intra-operative assessment of the displaced fragments, an automatic segmentation of the articular surfaces and color-coded visualization was developed. Methods: Our automatic approach consists of three major steps: first, using adjusted standard planes intersecting the articular region, the joint space is localized with an intensity profile-based method. In a second step, the localized joint space is segmented on the Laplacian of Gaussian filtered volumetric image by a modified binary flood fill algorithm. Finally, a 3D surface model of the segmented joint space is analyzed and visualized with focus on critical displacements of the surface. Results: A specifically designed human cadaver study consisting of ten lower legs of ten different donors was conducted to acquire 48 realistic C-arm CT images of misaligned bone fragments (steps of varying sizes) in the posterior talar articular surface of the calcaneus. The proposed algorithmic pipeline was verified by the acquired image data and showed very good results with no false positives and an overall correct displacement assessment of $$93.8\,\%$$ . Conclusions: The proposed algorithmic pipeline can be easily integrated into the clinical workflow and qualifies for intra-operative usage. It showed very good results on the reference data set of the cadaver study. With the help of such an assistance system, the time-consuming process of 2D view adjustment and visual assessment of the gray value images can be greatly simplified. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to quantitatively measure the morphology of the glenoid and to assess feasibility of using the medial tibial plateau surface as a donor for osteoarticular allograft reconstruction of the glenoid. Methods: Using computed tomography (CT), 10 tibias and 10 scapular models from our database (5 males and 5 females in each group) were randomly selected. Commercial software (Mimics, Materialize, Inc., Plymouth, MI) was used to extract the bone contours from the CT images and to reconstruct the 3-dimensional (3D) geometry of the scapula and tibia. By utilizing the software Creo Elements/Pro 5.0 (Parametric Technology Corp., Needham, MA), mean length and width of both the glenoid and medial tibial plateau were calculated. Radius of curvature was then measured in each 3D CT model at three intermediate segment points that were established within the length line at 25, 50, and 75 percent from superior to inferior in the glenoid and from posterior to anterior in the medial tibial plateau. Statistical analysis was performed and determined to be significant for P < 0.05. Results: The mean (±SD) radius of curvature values at the established 25, 50, and 75 percent segments of the glenoid were 47.4 ± 17.5 mm, 51.2 ± 12.4 mm, and 45.9 ± 17.0 mm, respectively. For the medial tibial plateau, the radius of curvature at 25, 50, and 75 percent were 43.5 ± 9.7 mm, 37.4 ± 14.3 mm and 52.3 ± 21.5 mm, respectively. Values of the glenoid length were 34.0 ± 2.9 mm, and width values were 24.4 ± 2.3 mm. For the medial tibial plateau, the length was 42.6 ± 2.7 mm, and the width was 23.3 ± 4.3 mm. There was no statistical difference in the radius of curvature and dimensional surface area between the glenoid and medial tibial plateau surfaces. Conclusion: The 3D CT-based anatomic study found that there is a statistically similar relationship in the radius of curvature of the glenoid and the medial tibial plateau surface. This concept may allow the medial tibial plateau to be used as a donor for osteoarticular allograft reconstruction of the glenoid, especially in young patients where previous studies have demonstrated that the success rate in shoulder replacements is not as good as in older patients. [ABSTRACT FROM AUTHOR]

Copyright of Der Unfallchirurg is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The thermomechanical reaction of the joint-synovial fluid system to periodic and impulse actions has been investigated. The behavior of the body of the joint near the articular surface - resistance of the bone material of the joint to periodic mechanical actions - has been established. It has been shown that the most destructive actions for the joint are instantaneous impulse shock mechanical actions. [ABSTRACT FROM AUTHOR]

This review deals with the relation between the anatomy and function of the ankle joint complex. The questions addressed are how high do the forces in the ankle joint get, where can the joints go (range of motion) and where do they go during walking and running. Finally the role of the ligaments and the articular surfaces is discussed, i.e. how does it happen. The magnitude of the loads on the ankle joint complex are primarily determined by muscle activity and can be as high as four times the body weight during walking. For the maximal range of motion, plantar and dorsiflexion occurs in the talocrural joint and marginally at the subtalar joint. In-eversion takes place at both levels. The functional range of motion is well within the limits of the maximal range of motion. The ligaments do not contribute to the forces for the functional range of motion but determine the maximal range of motion together with the articular surfaces. The geometry of the articular surfaces primarily determines the kinematics. Clinical studies must include these anatomical aspects to better understand the mechanism of injury, recovery, and interventions. Models can elucidate the mechanism by which the anatomy relates to the function. The relation between the anatomy and mechanical properties of the joint structures and joint function should be considered for diagnosis and treatment of ankle joint pathology. [ABSTRACT FROM AUTHOR]

This study’s objective was to compare the use of two biplanar angled radiographs versus standard posterioanterior (PA) and lateral radiographs in determining preservation of the articular space with regard to pin placement in the distal radius. Various combinations of inclination (pitch) and clockwise/counterclockwise rotation (roll) were used to determine the best view of the distal radius articular surface. Optimum visualization of the articular surface presented at 12° inclination plus 15° counterclockwise rotation for the PA view and 22° inclination and 15° counterclockwise rotation for the lateral view. Ten cadaveric forearms were dissected, and ten Kirschner wires (K-wires) were placed at specific surfaces of the distal radius. Each K-wire was countersunk 2 mm below the chondral surface so all K-wires resided within the subchondral bone. Each forearm was radiographed in four views; PA, lateral, pitch-and-roll PA (PR-PA), and pitch-and-roll lateral (PR-lateral). Four blinded reviewers evaluated the radiographs and marked whether they were certain, relatively certain, or uncertain that the K-wires did not penetrate into the articular space. Reviewers demonstrated significantly less uncertainty about intraarticular penetration ( p < 0.005) with both the PR-PA and PR-lateral views compared with standard PA and lateral views. The biconcave nature of the distal radius makes it extremely difficult to visualize placement of hardware with respect to the articular surface using standard radiographs. The use of PR-PA and PR-lateral views significantly improves the surgeon’s ability to judge the position of hardware in the distal radius compared to standard radiographic views, thus allowing for more meaningful clinical decision in post-operative radiographs. [ABSTRACT FROM AUTHOR]

The biomechanical function of articular cartilage relies crucially on its integration with both the subchondral bone and the wider continuum of cartilage beyond the directly loaded contact region. This study was aimed at visualizing, at the microanatomical level, the deformation response of cartilage including that of the non-directly loaded continuum. Cartilage-on-bone samples from bovine patellae were loaded in static compression until a near-equilibrium deformation was achieved, and then chemically fixed in this deformed state. Full-depth cartilage–bone sections, incorporating the indentation profile and beyond, were studied in their fully hydrated state using differential interference contrast microscopy. Morphometric measurements of the indented profile were used in combination with a force analysis of the tangential layer to investigate the extent to which the applied force is attenuated in moving away from the directly loaded region. This study provides microscopic evidence of a structure-related response in the transitional zone of the cartilage matrix. It is manifested as an intense chevron-type shear discontinuity arising from the constraints provided by both the strain-limiting articular surface and the osteochondral attachment. The discontinuity persists well into the non-directly loaded continuum of cartilage and is proposed as a force attenuation mechanism. The structural and biomechanical analyses presented in this study emphasize the important role of the complex microanatomy of cartilage, highlighting the interconnectivity and optimal recruitment of the load-bearing elements throughout the zonally differentiated cartilage depth. [ABSTRACT FROM AUTHOR]

Background: Partial-thickness tear of the subscapularis tendon in the articular surface is common. Hypothesis: Intra-articular repair of a partial articular-surface tear of the subscapularis tendon will provide a successful outcome. Study Design: Case series; Level of evidence, 4. Methods: A total of 29 shoulders with an isolated partial articular-surface tear of the subscapularis tendon without another rotator cuff lesion were treated with arthroscopic intra-articular repair using suture anchors. Biceps tenodesis was performed in 16 patients. Outcomes were prospectively evaluated at a mean of 27 months (range, 19-41 months) using 3 objective (University of California at Los Angeles, American Shoulder and Elbow Surgeons Shoulder Index, Simple Shoulder Test) and 2 subjective (pain and function visual analog scales) measurements. Results: There were 21 men and 8 women, with a mean age of 54 years (range, 41-65 years). Tear widths were small (<1 cm) in 16 shoulders and large (>1 cm) in 13 shoulders. Twenty-six shoulders had articular cartilage erosion on the adjacent humeral head. Lesions of the biceps tendon were noted in 25 patients (partial tear in 15 shoulders; subluxation in 13 shoulders). Shoulder pain scores improved after surgery (5.0 ± 2.7 to 0.3 ± 0.7, P < .05). According to American Shoulder and Elbow Surgeons Shoulder Index scores, 18 were excellent; 10, good; and 1, fair. Internal rotation strength deficit improved from 32% to 4%. Twenty-six patients returned to more than 90% of previous activity. There were no surgical complications; tear size and biceps tenodesis did not affect outcome (P > .05). Conclusion: Arthroscopic intra-articular repair of a partial articular-surface tear of the subscapularis tendon is an effective procedure that spares the intact tendon attachment in the bursal surface. Short-term outcomes were reliable by both objective and subjective measurements. [ABSTRACT FROM AUTHOR]

Cartilage taken from the osteoarthritic bovine patellae was used to investigate the progression of change in the collagenous architecture associated with the development of fibrillated lesions. Differential interference contrast optical microscopy using fully hydrated radial sections revealed a continuity in the alteration of the fibrillar architecture in the general matrix consistent with the progressive destructuring of a native radial arrangement of fibrils repeatedly interconnected in the transverse direction via a non-entwinement-based linking mechanism. This destructuring is shown to occur in the still intact regions adjacent to the disrupted lesion thus rendering them more vulnerable to radial rupture. Two contrasting modes of surface rupture were observed and these are explained in terms of the absence or presence of a skewed structural weakening of the intermediate zone. A mechanism of surface rupture initiation based on simple bi-layer theory is proposed to account for the intensification of surface ruptures observed in the intact regions on advancing towards the fibrillation front. Focusing specifically on the primary collagen architecture in the cartilage matrix, this study proposes a pathway of change from intact to overt disruption within a unified structural framework. [ABSTRACT FROM AUTHOR]

The covering of ultra high molecular weight polyethylene (UHMWPE) and calcium hydroxyapatite (HA)/tricalcium phosphate (TCP) porous solid substrate with polyHEMA hydrogel has been studied aiming at the development of devices to be used as artificial articular surfaces in joint prosthesis or osteochondral repair grafts. Commercial porous UHMWPE was used. Ceramic porous substrate was prepared by load compaction of an HA and TCP powder mixture obtained by aqueous precipitation technique. Two different compaction loads and grain size distribution was used. Polymer particles were added to the powder mixture in order to increase the substrate porosity after the sintering process. The porous substrate was covered with polyHEMA hydrogel by in situ polymerization. Morphological analysis (SEM) showed that a hydrogel layer formed in the porous solid top surface was fixed to the substrate by mechanical interlocking because the porous surface was filled by the hydrogel. After hydrogel covering, the resultant devices showed a decrease in the compressive elastic modulus that was influenced by the porous substrate material. [ABSTRACT FROM AUTHOR]

The peripheral discal tissue and the surface covering layer have been studied in normal and in variously damaged human temporo-mandibular joint discs. In the normal disc the tissue consisted of dense bundles of fibers and rare fibrocytes. The surface of the disc was covered by a regular basophilic and electron-dense layer. These morphological characteristics persisted also in some pathological discs in which fibrous derangements had already occurred in the deep parts. In very deformed and damaged discs associated with serious functional anomalies, the superficial discal tissue consisted of rare fibers dispersed in a loose ground substance and of an increased number of cells. The superficial coating was formed by an irregular dense lamina and aggregates of various materials containing cellular debris, vesicles, filaments and amorphous components. These deposits are probably due to degeneration processes of discal tissue. This investigation suggests that the superficial discal tissue and the covering layer are together involved in maintaining the functional properties of the articular surfaces. Their structural modification in severe functional anomalies leads to failure in the maintenance of nonadherence conditions and to deterioration of the functional defect. [ABSTRACT FROM AUTHOR]

Previous studies have shown that synovial surfactant could have beneficial roles in the joint, especially as a very effective boundary lubricant capable of high load bearing. This study is aimed at further characterization and identification of the source. Known to be an important minor component of pulmonary surfactant, proteolipid has now been detected in appreciable quantities in bovine synovial fluid and bound to the articular surface. Using standard procedures to separate it from the major component [surface-active phospholipid (SAPL)] by column chromatography, proteolipid :phospholipid ratios were found to be comparable to those in the lung or in lamellar bodies (LBs). LBs are the unequivocal source of surfactant in the lung and we have confirmed an earlier study demonstrating their presence in Type B synoviocytes. Using a fixation procedure specifically designed to preserve the graphite-like structure of SAPL deposited as oligolamellar layers, or coiled as lamellar bodies, we were able to demonstrate these structures in equine joints adjacent to the Golgj apparatus associated with the secretory mechanism of the cell. These results indicate that proteolipid could be facilitating the deposition of the graphite-like surface lining of SAPL providing efficient boundary lubrication just as it promotes surfactant adsorption in the lung and in the formation of myelin. Any deficiency in synovial surfactant, compromising its roles in the joint, is discussed in relation to osteoarthritis and the possible administration of exogenous SAPL to the degenerating joint. [ABSTRACT FROM PUBLISHER]

Changes in craniofacial growth after a period of unilateral masticatory function were studied in rabbits. 10-day-old animals were divided into 3 groups. In Group I, mandibular and maxillary molars were ground down 2 × a week on the right side under general anesthesia until age 50 days, and were thereafter left to grow without grinding. In Group II, the right-side molars were ground until age 40 days on. Between days 40 and 60, grinding was performed on the left side. The animals were thereafter left to grow. Group III consisted of unoperated control animals. All of the animals were fed whole pellets and water ad libitum, and were sacrificed at age 100 days. There were measurable differences in growth after periods of unilateral masticatory function. The mandibular ramus was higher, the condylar processus was larger sagittally. and angles between the anterior or posterior borders of the condylar process and inferior border of mandible were smaller in the treated than in the control animals, and there were differences between right and Jeff sides of the same animal in the maxilla and mandible. The inclination of the articular surface of the glenoid fossa was steeper anteriorly on both sides in the treated than in the controls. It was concluded that growth after a period of unilateral masticatory function in young rabbits does not rectify all of the asymmetric changes in the maxilla, mandible and glenoid fossa resulting from the asymmetric function. [ABSTRACT FROM AUTHOR]

In this study the main purpose was to investigate the effect of altered masticatory function on the shape and inclination of the articular surface of the glenoid fossa, and on the growth of the mandible in the rabbit. The maxillary and mandibular molars of 14, 10-d-old rabbits were ground down to the gingiva on the right side twice a week; 9 were controls. At age 50 d all rabbits were killed, soft tissue. of the heads was removed, and the measurements were made. The inclination of the articular surface of the glenoid fossa was shallower on both sides in the experimental group than in the controls; the difference was greater on the right side. There were dimensional and angular differences between right and left sides of the mandible and maxilla in the experimental animals. In conclusion, unilateral masticatory function was found to cause an asymmetric cranio-facial growth. Furthermore, function has an effect on the shape of the glenoid fossa, especially on the balancing side, in conjunction with asymmetric function. [ABSTRACT FROM AUTHOR]

The direct effects on the cartilage articular surface of three anti-inflammatory drugs (Diclofenac, Pirprofen and acetyl-salicylic acid) and of a polysulfated glycosaminoglycan (Arteparon), were studied using an in vitro system in which BALB-c mouse femoral heads were incubated with the drugs. After incubation and labeling of the negative charges of the articular surfaces with cationized ferritin, the femoral heads were examined by electron microscopy. In addition, the effect of the drugs on the aggressive action of collagenase on the articular surface was tested using the same in vitro system. Diclofenac, Pirprofen and the polysulfated glycosaminoglycan did not alter the structure or the charge properties of the surface. Acetyl salicylic acid produced a slight disruption of the articular surface. The drugs studied had no effect on the disruptive action of collagenase. [ABSTRACT FROM AUTHOR]

The magnitude and the direction of the resultant hip joint force are different in different body positions during gait. Therefore the stress distribution in the hip joint articular surface also changes. The aim of this work is to study how the stress distribution changes if the magnitude and the direction of the hip joint force is changed during gait. For this purpose a three-dimensional mathe-matical model is developed. We calculated the values of the peak stress and the location of the pole on the articular surface (where the stress is maximal) in the successive phases of the walking cycle. The values of the peak stress range from 0.8 MPa in the one limb stance phase to 2.6 MPa in the heel strike phase. [ABSTRACT FROM AUTHOR]