A pilot feasibility study for ultrasound evaluation of living human wrist cartilage: site-specific differences in acoustic properties

Musculoskeletal ultrasonography for arthropathy assessment in patients with hemophilia: A single-center cross-sectional study from Shanxi Province, China

Magnetic resonance imaging (MRI) is currently considered the gold standard for assessing hemophilic arthropathy (HA) severity; however, MRI is often costly, time-consuming, and difficult to perform in children. In the present study, we evaluated the joint status of hemophilic patients from Shanxi Province, China, using musculoskeletal ultrasonography (MSKUS) and identified the factors that most strongly correlated with disease severity.The study included 104 patients with hemophilia, who underwent MSKUS examination. A total of 1248 joints (including the shoulder, elbow, wrist, hip, knee, and ankle joints on both sides) from these patients were evaluated. Effusion, hypertrophy, cartilage modification, and bone erosion were assessed. The chi-square test was used to analyze categorical variables, and multivariate logistic regression was used to analyze the relationship between joint disease and risk factors.MSKUS allowed clear visualization of synovial lesions, effusion, cartilage modification, and bone surface damage; however, it was unable to identify changes deep within bones. The distribution of damaged joints was as follows: shoulder, 2 (1.0%); elbow, 80 (38.5%); wrist, 4 (1.9%); hip, 4 (1.9%); knee, 126 (60.6%); and ankle, 90 (43.3%). Damage was more common in the knee, elbow, and ankle joints than in the shoulder, wrist, and hip joints (P < .001). Among the 1248 joints, 306 showed lesions, which included effusion in 102 (8.2%) joints, synovium hypertrophy in 176 (14.1%), cartilage modification in 193 (15.5%), and bone damage in 176 (14.1%). Many joints had multiple lesions at the same time. The chi-square test and multivariate logistic analysis showed that age and hemophilia severity were significantly associated with joint disease, while type of hemophilia and treatment categories were not associated with joint disease.MSKUS is a convenient and cost-effective examination that can play an important role in the diagnosis and long-term monitoring of HA.

In Vivo Evaluation of the Potential of High-Frequency Ultrasound for Arthroscopic Examination of the Shoulder Joint

OBJECTIVE

Accurate arthroscopic evaluation of cartilage lesions could significantly improve the outcome of repair surgery. In this study, we investigated for the first time the potential of intra-articular ultrasound as an arthroscopic tool for grading cartilage defects in the human shoulder joint in vivo and compared the outcome to results from arthroscopic evaluation and magnetic resonance imaging findings.

DESIGN

A total of 26 sites from 9 patients undergoing routine shoulder arthroscopy were quantitatively evaluated with a clinical intravascular (40MHz) ultrasound imaging system, using the regular arthroscopy portals. Reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB), and ultrasound roughness index (URI) were calculated, and high-resolution ultrasound images were obtained per site. Each site was visually graded according to the International Cartilage Repair Society (ICRS) system. "Ultrasound scores" corresponding to the ICRS system were determined from the ultrasound images. Magnetic resonance imaging was conducted and cartilage integrity at each site was classified into 5 grades (0 = normal, 4 = severely abnormal) by a radiologist.

RESULTS

R and IRC were lower at sites with damaged cartilage surface (P = 0.033 and P = 0.043, respectively) and correlated with arthroscopic ICRS grades (r s = -0.444, P = 0.023 and r s = -0.426, P = 0.03, respectively). Arthroscopic ICRS grades and ultrasound scores were significantly correlated (rs = 0.472, P = 0.015), but no significant correlation was found between magnetic resonance imaging data and other parameters.

CONCLUSION

The results suggest that ultrasound arthroscopy could facilitate quantitative clinical appraisal of articular cartilage integrity in the shoulder joint and provide information on cartilage lesion depth and severity for quantitative diagnostics in surgery.

Spectroscopic measurement of cartilage thickness in arthroscopy: ex vivo validation in human knee condyles

PURPOSE

To evaluate the accuracy of articular cartilage thickness measurement when implementing a new technology based on spectroscopic measurement into an arthroscopic camera.

METHODS

Cartilage thickness was studied by ex vivo arthroscopy at a number of sites (N = 113) in human knee joint osteoarthritic femoral condyles and tibial plateaus, removed from 7 patients undergoing total knee replacement. The arthroscopic image spectral data at each site were used to estimate cartilage thickness. Arthroscopically derived thickness values were compared with reference cartilage thickness as measured by 3 different methods: needle penetration, spiral computed tomography scanning, and geometric measurement after sample slicing.

RESULTS

The lowest mean error (0.28 to 0.30 mm) in the regression between arthroscopic and reference cartilage thickness was seen for reference cartilage thickness less than 1.5 mm. Corresponding values for cartilage thickness less than 2.0 and 2.5 mm were 0.32 to 0.40 mm and 0.37 to 0.47 mm, respectively. Cartilage thickness images--created by pixel-by-pixel regression model calculations applied to the arthroscopic images--were derived to demonstrate the clinical use of a camera implementation.

CONCLUSIONS

On the basis of this investigation on osteoarthritic material, when one is implementing the spectroscopic method for estimating cartilage thickness into an arthroscopic camera, errors in the range of 0.28 to 0.30 mm are expected. This implementation does not, however, influence the fact that the spectral method performs less well in the cartilage thickness region from 1.5 to 2.5 mm and cannot assess cartilage thicker than 2.5 mm.

CLINICAL RELEVANCE

Imaging cartilage thickness directly in the arthroscopic camera video stream could serve as an interesting image tool for in vivo cartilage quality assessment, in connection with cartilage diagnosis, repair, and follow-up.

Effect of laser acupuncture on disuse osteoarthritis: an ultrasound biomicroscopic study of patellar articular cartilage in rats

To investigate the effect of laser acupuncture (LA) on disuse changes in articular cartilage using ultrasound biomicroscopy (UBM), Eighteen rats were randomly divided into the control group (C), the tail-suspended group (T), and the tail-suspended with LA treatment group (L). During 28-day suspension period, group L were treated with LA at acupoints on the left hindlimb while group T had a sham treatment. Ultrasound roughness index (URI), integrated reflection coefficient (IRC), integrated backscatter coefficient (IBC), cartilage thickness, and ultrasonographic score (US) of articular cartilage at patella were measured by using an ultrasound biomicroscopy system (UBS). Compared with the group C, URI significantly (P < 0.01) increased by 60.9% in group T, increased by 38.1% in group L. In addition, unloading induced a significant cartilage thinning (P < 0.05) in group T, whereas cartilage thickness in group L was 140.22 ± 19.61 μm reaching the level of the control group (147.00 ± 23.99 μm). There was no significant difference in IRC, IBC, and US among the three groups. LA therapy could help to retain the quality of articular cartilage which was subjected to unloading. LA would be a simple and safe nonpharmacological countermeasure for unloading-induced osteoarthritis. The UBM system has potential to be a sensitive, specific tool for quantitative assessment of articular cartilage.

Arthroscopic Ultrasound Assessment of Articular Cartilage in the Human Knee Joint: A Potential Diagnostic Method

OBJECTIVE

We tested whether an intra-articular ultrasound (IAUS) method could be used to evaluate cartilage status arthroscopically in human knee joints in vivo.

DESIGN

Seven patients undergoing arthroscopic surgery of the knee were enrolled in this study. An ultrasonic examination was conducted using the same portals as in the arthroscopic surgery. A high-frequency (40-MHz) ultrasound transducer (diameter = 1 mm) was directed to the desired location on the articular surface under arthroscopic control. In addition to ultrasound data, an IAUS video and optical video through the arthroscope were recorded. Classification of cartilage injuries according to International Cartilage Repair Society, as conducted by the orthopedic surgeon, provided reference data for comparison with the IAUS.

RESULTS

The IAUS method was successful in imaging different characteristics of the articular surfaces (e.g., intact surface, surface fibrillation, and lesions of varying depth). In some cases, also the subchondral bone and abnormal internal cartilage structure were visible in the IAUS images. Specifically, using the IAUS, a local cartilage lesion of 1 patient was found to be deeper than estimated arthroscopically.

CONCLUSIONS

The IAUS method provided a novel arthroscopic method for quantitative imaging of articular cartilage lesions. The IAUS provided quantitative information about the cartilage integrity and thickness, which are not available in conventional arthroscopy. The present equipment is already approved by the Food and Drug Administration for intravascular use and might be transferred to intra-articular use. The invasiveness of the IAUS method might restrict its wider clinical use but combined with arthroscopy, ultrasonic assessment may enlarge the diagnostic potential of arthroscopic surgery.

A spectroscopic approach to imaging and quantification of cartilage lesions in human knee joints

We have previously described a technology based on diffuse reflectance of broadband light for measuring joint articular cartilage thickness, utilizing that optical absorption is different in cartilage and subchondral bone. This study is the first evaluation of the technology in human material. We also investigated the prospects of cartilage lesion imaging, with the specific aim of arthroscopic integration. Cartilage thickness was studied ex vivo in a number of sites (n = 87) on human knee joint condyles, removed from nine patients during total knee replacement surgery. A reflectance spectrum was taken at each site and the cartilage thickness was estimated using the blue, green, red and near-infrared regions of the spectrum, respectively. Estimated values were compared with reference cartilage thickness values (taken after sample slicing) using an exponential model. Two-dimensional Monte Carlo simulations were performed in a theoretical analysis of the experimental results. The reference cartilage thickness of the investigated sites was 1.60 ± 1.30 mm (mean ± SD) in the range 0-4.2 mm. Highest correlation coefficients were seen for the calculations based on the near-infrared region after normalization to the red region (r = 0.86) and for the green region (r = 0.80).