Musculoskeletal

Introduction

Our department has a keen interest in all aspects of musculoskeletal imaging, particularly ultrasound, and the pursuit of new innovative imaging methods and analytics. 

We are particularly proud of our pioneering work on addressing bone marrow changes in osteoporosis, quantifying glenoid bone loss, classification of talar dome osteochondral lesions, accuracy of ultrasound for classifying soft tissue masses, traction MR imaging of joints, identifying rib fractures on ultrasound, assessment of carpal tunnel syndrome on ultrasound, population reference ranges for developmental spinal canal size, assessing inflammatory changes in rheumatoid arthritis and spondylopathy, positional MRI of the normal and injured knee and more recently the discovery of two rheumatoid arthritis structural phenotypes.

Our main current research interests are the imaging of tibiofemoral joint stability, direct traction MR imaging of joints, and quantifying inflammation in rheumatoid arthritis.

Using a simple positional MR technique, we have shown how patients with ACL and other non-ACL injuries have significant changes in translation and rotation.  While there is a wide variation in tibiofemoral movement among normal subjects, there is relatively little side-to-side variation. 

We are currently exploring this further with a positional CT-based study.

We have shown how traction improves visualization of the articular cartilage, intrinsic ligaments, and triangular fibrocartilaginous complex in the wrist joint as well as improving cartilage visibility in the ankle, hip, and elbow. We are now in the process of developing and testing more direct, practical, and user-friendly traction devices for the wrist, ankle, and hip joints.

MRI exquisitely reveals inflammatory change in rheumatoid arthritis. We are following up a cohort of 131 early rheumatoid arthritis patients with MRI examination at baseline, year 1 and year 8. We have developed automated methods of quantifying bone marrow oedema on MRI and are in the process of developing a method of automatically quantifying the degree of bone marrow oedema and synovitis.

We have undertaken pioneering work on marrow changes in osteoporosis, being one of the first to recognize that:

• Osteoporosis is associated with both an increase in marrow fat and reduced marrow perfusion. We have also explored the reasons behind this impaired marrow perfusion.
• Similar changes are seen in the proximal femur with most reduction in perfusion occurring in the region of the femoral neck. 
• Marrow fat increases dramatically in females around the time of the menopause
• This research has opened up a completely new way and approach to looking at osteoporosis and many researchers have begun exploring into this area since our first papers were published in 2005 and 2006. Before our first papers were published, not a single paper had dealt with marrow changes in osteoporosis. This is now a very substantial area of research from groups interested in osteoporosis across America, Europe and China.

• First to show a method of non-invasively measuring glenoid bone loss. 
• First to show how glenoid one loss occurs from the anterior aspect of the glenoid rather than from the antero-inferior aspect of the glenoid as previously thought. 
• First to describe the anterior straight line.
• First to show method of measuring glenoid bone loss on MRI.
• First to show excellent side-to-side symmetry in glenoid measurements and contour.  
• First to determine the high prevalence of glenoid bone loss in shoulder dislocation. 
• Our CT- and MR-based methods of measuring glenoid bone loss have been accepted as the worldwide norm and now is routinely used. Before our research, there was no known means of measuring glenoid bone loss non-operatively.

• First to develop a very widely used 8-grade system for disc degeneration on MR
• First to show that menopause leads to accelerated disc degeneration after the menopause. 
• First to show that the diagnostic capability of low-field is comparable to high field MRI. 
• First to develop a population reference range for developmental size of both the cervical and luisa the spinal canals.

• First to show the accuracy of ultrasound in diagnosing acute rib fracture 
• First to show low accuracy of radiographs in detecting rib fractures

• First to describe an MR technique to differentiate and measure the two main bundles of the ACL. This allows an accurate evaluation of partial tears and the degree of involvement of each bundle. 
• Oblique axial imaging is now a widely practiced MR imaging technique 
• First to show that the screw home mechanism is lost in ACL tears

• First to describe value of high-resolution small FOV coil imaging in talar dome osteochondral lesions 
• First to describe a grading system for talar dome osteochondral lesions on MR which includes features such as chondral separation and hypertrophy

• First prospective studies on ultrasound of superficial and deep soft tissue tumours determining the accuracy of ultrasound in the specific diagnosis of superficial soft tissue tumours            

• World leader in traction MR imaging of peripherals joints 
• First to show major benefit of traction MRI in demonstrating injury to wrist ligaments, cartilage and triangular fibrocartilage complex. Several research projects underway.
• First report of traction MR arthrography of the elbow

• In conjunction with my colleagues in the Dept of Medicine (Prof LS Tam) and Orthopedics (Prof Qin Ling), we have investigated bone density, microstructure, and strength of the distal radius using HR-pQCT and MRI in patients with RA, psoriasis and SLE and are actively pursuing several research projects in this area.

• Numerous studies have demonstrated that the skeleton of East Asians has microstructural and mechanical advantages. It is noted that postmenopausal Chinese women have a higher trabecular plate-to-rod ratio and greater whole bone stiffness, translating into greater trabecular mechanical competence. Compared with Caucasians, both pre- and postmenopausal Chinese women had greater cortical thickness, cortical tissue mineral density, and reduced cortical porosity. Fragility fracture prevalences among Chinese are no more than half that of older Caucasians, both for men and women. We recommended the osteoporosis cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.7 for Chinese women. For older Chinese men, we recommended the cutpoint values for T-score of femoral neck, total hip, and spine to be -2.7, -2.6, and -3.2. For Caucasian women, the QCT (quantitative CT) lumbar spine bone mineral density cutpoint value for classifying osteoporosis is 80 mg/ml. We suggest that the QCT cutpoint value for classifying osteoporosis among older East Asian women will be 45-50 mg/ml lumbar spine bone mineral density

References

• Wáng YXJ, Griffith JF, Blake GM, Diacinti D, Xiao BH, Yu W, Su Y, Jiang Y, Guglielmi G, Guermazi A, Kwok TCY. Revision of the 1994 World Health Organization T-score definition of osteoporosis for use in older East Asian women and men to reconcile it with their lifetime risk of fragility fracture. Skeletal Radiol. 2024;53:609-625.
• Wáng YXJ, Blake GM, Tang SN, Guermazi A, Griffith JF. Quantitative CT lumbar spine BMD cutpoint value for classifying osteoporosis among older East Asian women should be lower than the value for Caucasians. Skeletal Radiol. 2024 Feb 27. doi: 10.1007/s00256-024-04632-4.

• We have been researching vertebral fragility fracture for many years. We were the first to report that vertebral fragility fracture prevalence and severity among Chinese are no more than half of that of Caucasians, both for women and for men. We also majorly revised the radiographic diagnosis criteria for vertebral fragility fracture and authored the first consensus of radiographic diagnosis of vertebral fragility fracture. We concluded that older Chinese have a generally healthier spine relative to older Caucasians.

References

• Wáng YXJ, Diacinti D, Leung JCS, Iannacone A, Kripa E, Kwok TCY, Diacinti D. Much lower prevalence and severity of radiographic osteoporotic vertebral fracture in elderly Hong Kong Chinese women than in age-matched Rome Caucasian women: a cross-sectional study. Arch Osteoporos. 2021;16:174.
• Wáng YXJ, Diacinti D, Aparisi Gómez MP, Santiago FR, Becce F, Tagliafico AS, Prakash M, Isaac A, Dalili D, Griffith JF, Guglielmi G, Bazzocchi A. Radiological diagnosis of prevalent osteoporotic vertebral fracture on radiographs: an interim consensus from a group of experts of the ESSR osteoporosis and metabolism subcommittee. Skeletal Radiol. 2024 Apr 25. doi: 10.1007/s00256-024-04678-4.
• Wáng YXJ, Deng M, Griffith JF, Kwok AWL, Leung JCS, Lam PMS, Yu BWM, Leung PC, Kwok TCY. ‘Healthier Chinese spine’: an update of osteoporotic fractures in men (MrOS) and in women (MsOS) Hong Kong spine radiograph studies. Quant Imaging Med Surg 2022;12(3):2090-2105.