99mTc HMDP bone scanning in generalised nodal osteoarthritis. I. Comparison of the standard radiograph and four hour bone scan image of the hand

Dorso-ventral osteophytes of interphalangeal joints correlate with cartilage damage and synovial inflammation in hand osteoarthritis: a histological/radiographical study

Objective

To detect dorsally located osteophytes (OP) on lateral x-ray views and to correlate their presence with the extent of structural joint damage, determined by histologic grading (cartilage damage and synovial inflammation) and radiographic scoring in hand osteoarthritis (HOA).

Methods

Distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints were obtained from post mortem specimens (n = 40). Multiplanar plain x-rays were taken (dorso/palmar (dp) and lateral views). Radiographic OA was determined by the Kellgren and Lawrence classification. Joint samples were prepared for histological analysis and cartilage damage was graded according to the Mankin scoring system. Inflammatory changes of the synovial membrane were scored using the general synovitis score (GSS). Spearman’s correlation was applied to examine the relationship between histological and radiographical changes. Differences between groups were determined by Mann-Whitney test.

Results

Bony proliferations that were only detectable on lateral views but reminiscent of OPs on dp images were termed dorso-ventral osteophytes (dvOPs). All joints displaying dvOPs were classified as OA and the presence of dvOPs in DIP and PIP joints correlated with the extent of histological and radiographic joint damage, as well as with patient age. Joint damage in osteoarthritic DIP and PIP joints without any dvOPs was less severe compared to joints with dvOPs. Synovial inflammation was mainly present in joints displaying dvOPs and correlated with joint damage.

Conclusion

dvOPs are associated with increasing structural alterations in DIP and PIP joints and can be seen as markers of advanced joint damage. Detecting dvOPs can facilitate the diagnosis process and improve damage estimation in HOA.

Early osteoarthritis of the knee

There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA.

Association between cartilage degeneration and subchondral bone remodeling in patients with knee osteoarthritis comparing MRI and (99m)Tc-DPD-SPECT/CT

OBJECTIVE

The purpose of this retrospective cross-sectional study was to investigate the association between cartilage lesions assessed with 3T-MRI and remodeling of the subchondral bone detected by (99m)Tc-DPD-SPECT/CT.

DESIGN

(99m)Tc-DPD-SPECT/CT and MRI of 27 knees of 25 patients with chronic knee pain and risk factors for osteoarthritis (OA) were evaluated by one nuclear physician and one radiologist. Six regions of the knee (in total 162 regions in 27 knees) were assessed according to structural joint lesions graded with a modified Whole Organ MR imaging score (WORMS) and according to subchondral (99m)Tc-DPD-SPECT uptake. Relationships between regional WORMS scores and uptake were quantified using general estimating equations. In a secondary analysis the uptake sum with the WORMS sum per joint was compared using Spearman correlations.

RESULTS

Elevated subchondral uptake was significantly associated with the grade of cartilage lesions (P < 0.0001). Mean uptake was significantly higher subjacent to full thickness cartilage lesions compared to partial thickness lesions (P < 0.0001). A similar association was observed between bone marrow edema pattern (BMEP) and cartilage lesions. The sum of uptakes per joint was positively correlated to the WORMS sum (rs = 0.42) and to the sum of cartilage lesions per joint (rs = 0.50).

CONCLUSION

Both functional and structural changes of the subchondral bone in terms of scintigraphic osseous activity and the presence and degree of BMEP were significantly associated with cartilage lesions in patients with OA of the knee. This association was pronounced with full thickness lesions, indicating a possible protective effect of the cartilage layer for the subjacent bone.

Alterations in periarticular bone and cross talk between subchondral bone and articular cartilage in osteoarthritis

The articular cartilage and the subchondral bone form a biocomposite that is uniquely adapted to the transfer of loads across the diarthrodial joint. During the evolution of the osteoarthritic process biomechanical and biological processes result in alterations in the composition, structure and functional properties of these tissues. Given the intimate contact between the cartilage and bone, alterations of either tissue will modulate the properties and function of the other joint component. The changes in periarticular bone tend to occur very early in the development of OA. Although chondrocytes also have the capacity to modulate their functional state in response to loading, the capacity of these cells to repair and modify their surrounding extracellular matrix is relatively limited in comparison to the adjacent subchondral bone. This differential adaptive capacity likely underlies the more rapid appearance of detectable skeletal changes in OA in comparison to the articular cartilage. The OA changes in periarticular bone include increases in subchondral cortical bone thickness, gradual decreases in subchondral trabeular bone mass, formation of marginal joint osteophytes, development of bone cysts and advancement of the zone of calcified cartilage between the articular cartilage and subchondral bone. The expansion of the zone of calcified cartilage contributes to overall thinning of the articular cartilage. The mechanisms involved in this process include the release of soluble mediators from chondrocytes in the deep zones of the articular cartilage and/or the influences of microcracks that have initiated focal remodeling in the calcified cartilage and subchondral bone in an attempt to repair the microdamage. There is the need for further studies to define the pathophysiological mechanisms involved in the interaction between subchondral bone and articular cartilage and for applying this information to the development of therapeutic interventions to improve the outcomes in patients with OA.

Biological aspects of early osteoarthritis

PURPOSE

Early OA primarily affects articular cartilage and involves the entire joint, including the subchondral bone, synovial membrane, menisci and periarticular structures. The aim of this review is to highlight the molecular basis and histopathological features of early OA.

METHODS

Selective review of literature.

RESULTS

Risk factors for developing early OA include, but are not limited to, a genetic predisposition, mechanical factors such as axial malalignment, and aging. In early OA, the articular cartilage surface is progressively becoming discontinuous, showing fibrillation and vertical fissures that extend not deeper than into the mid-zone of the articular cartilage, reflective of OARSI grades 1.0-3.0. Early changes in the subchondral bone comprise a progressive increase in subchondral plate and subarticular spongiosa thickness. Early OA affects not only the articular cartilage and the subchondral bone but also other structures of the joint, such as the menisci, the synovial membrane, the joint capsule, ligaments, muscles and the infrapatellar fat pad. Genetic markers or marker combinations may become useful in the future to identify early OA and patients at risk.

CONCLUSION

The high socioeconomic impact of OA suggests that a better insight into the mechanisms of early OA may be a key to develop more targeted reconstructive therapies at this first stage of the disease.

LEVEL OF EVIDENCE

Systematic review, Level II.

Osteoarthritis of the distal interphalangeal joint

Osteoarthritis occurs with the highest prevalence in the distal interphalangeal joint of the hand and has been divided into an erosive and a nonerosive form. The pathogenesis of the early stages of osteoarthritis is poorly understood, but considerable emphasis has been placed on the role of cartilage and subchondral bone as well as soft tissue structures such as collateral ligaments and tendons. Radiographic evaluation represents the most standardized method to quantify disease progression, with different systems having been developed for defining and grading radiographic features. This current concepts article examines the recent knowledge base regarding the etiology, pathogenesis, and evaluation of osteoarthritis of the distal interphalangeal joint.

Role of bone in osteoarthritis pathogenesis

Much of the attention in developing diagnostic tools and therapeutic interventions for the management of osteoarthritis (OA) has focused on the preservation or repair of articular cartilage. It is clear that all of the joint components, including the ligaments, tendons, capsule, synovial lining, and periarticular bone, undergo structural and functional alterations during the course of OA progression. This article focuses on the specific skeletal features of OA and the putative mechanisms involved in their pathogenesis.

Scintigraphy in rheumatic diseases

The aim of this review is to summarise the clinical role of nuclear medicine in rheumatology taking into consideration the most specific diagnostic applications and other worthwhile therapeutic contributions. Traditional bone scintigraphy and recent inflammation-targeting radiopharmaceuticals, such as radiolabelled leucocytes and immunoscintigraphy, now allow us to obtain highly sensitive total-body and tomographical imaging information that can be used for the diagnosis of osteoarticular disease. The most common extra-articular manifestations of rheumatic diseases due to digestive, central nervous, respiratory and cardiovascular system involvement can be diagnosed by specific scintigraphic methods. Radiosynovectomy plays an important role in providing effective treatment for some joint diseases that are resistant to pharmacological therapy. Diagnostic and therapeutic applications of nuclear medicine show the highest efficacy in the early phase of rheumatic diseases. In more advanced stages, scintigraphical techniques play a complementary role to radiographical investigations in the assessment of prognosis and therapy efficacy.

Subchondral bone changes in hand and knee osteoarthritis detected by radiography

OBJECTIVE

To describe the changes in subchondral bone that occur with the onset and progression of osteoarthritis (OA) from macroradiographic assessment of patient's hand and knee joints.

DESIGN

The high magnification and spatial resolution of macroradiography permits detailed anatomical changes to be detected in OA joints. Data on the subchondral cortical and cancellous bone, recorded from both cross-sectional and longitudinal studies of hand and knee OA, are described and discussed with reference to recent findings on the altered biomechanical properties of OA bone.

RESULTS

In OA joints, both subchondral cortical plate and subjacent horizontal trabeculae increase in thickness early, prior to joint space narrowing (JSN). With progression, cortical plate sclerosis increased in 60% of OA hands and did not change in knee OA until JSN <1.5mm in the medial diseased compartment. In knee OA, trabeculae, at sites of tibial subchondral sclerosis, increased in number and extent, changes that overlay a subarticular region that was osteoporotic. With cartilage loss, the articular surfaces in some knees appeared corrugated, and later, with bone-on-bone, the surfaces became flattened and deformed.

CONCLUSIONS

The weaker than normal bone within thickened subchondral cortical plate and trabeculae of OA joints leads, in advanced OA, to deformation of the articular surfaces and absorption of local stresses producing an effect similar to stress-shielding. This effect, it is suggested, results in the subarticular osteoporosis.

Scintigraphic image patterns in dysplastic coxarthrosis: evaluation with reference to radiographic findings in 210 hips

Little is known about scintigraphic image patterns in the various stages of coxarthrosis. We assessed bone scintigraphy in 159 patients (210 hips) with dysplastic arthrosis of the hip. Scintigraphic images were divided into 5 types related to the radiographic stages of the disease. The scintigraphic images showed little, if any, uptake in the stage of prearthrosis. In the early stage, we found an increase in uptake in the weight bearing area in 30% of cases. In the advanced stage, more than half of the cases had an increase in uptake in the medial side of the joint and in the weight bearing area. In the terminal stage, a marked increase in uptake in the weight bearing area was commonest. Since the osteoblastic reaction intensified, a marked increase in uptake was seen not only in the weight bearing area, but also throughout the entire joint. These types of scintigraphic patterns, which change with the stage of coxarthrosis, seem to reflect the natural course of the disease. All hips with rapid progression of the disease showed a marked increase in uptake of radionuclide the entire joint at earlier stages.

Bone scintigraphy for osteonecrosis of the knee in patients with non-traumatic osteonecrosis of the femoral head: comparison with magnetic resonance imaging

OBJECTIVE

To determine whether technetium bone scintigraphy (BS) is useful for screening of non-traumatic osteonecrosis of the knee (ONK), which was a major affected site, secondary to the femoral head, among multiple osteonecrosis, in patients with non-traumatic osteonecrosis of the femoral head (ONFH).

METHODS

A total of 214 knee joints in 107 patients with ONFH were evaluated by BS and a comparison made with magnetic resonance imaging (MRI). ONK was classified into five sites, including the femoral condyles (ONFC), distal femoral metaphysis (ONFM), tibial plateau (ONTP), proximal tibial metaphysis (ONTM), and patella (ONP).

RESULTS

Based on the diagnosis by MRI, ONK was detected in 103 knees of 62 patients (48%). ONFC was most common (86 knees, 40%), ONFM (15%), followed by ONTM (10%), ONP (3%), and ONTP (0.9%). Sensitivity, specificity, and accuracy of BS for ONFC detection were 63%, 71%, and 68%, respectively. When the ONFC lesions on the coronal views of MRI were large or medium sized and occupied two thirds, or the entire anteroposterior joint surface on the sagittal views, the sensitivity of BS for ONFC detection increased to 89% (34/38 knees). The sensitivity of BS for ONFM, ONTM, and ONP detection was 3%, 0%, and 0%, respectively, but these lesions showed a low likelihood of collapse.

CONCLUSION

BS is useful for screening large ONK in patients with ONFH given that 89% of patients with ONFC who had a high risk of collapse of the knee were identified.

Bone scintigraphy in chronic knee pain: comparison with magnetic resonance imaging

OBJECTIVE

To compare increased bone uptake of 99Tcm-MDP and magnetic resonance (MR) detected subchondral lesions, osteophytes, and cartilage defects in the knee in middle aged people with long-standing knee pain.

METHODS

Fifty eight people (aged 41-58 years, mean 50) with chronic knee pain, with or without radiographic knee osteoarthritis, were examined with bone scintigraphy. The pattern and the grade of increased bone uptake was assessed. On the same day, a MR examination on a 1.0 T imager was performed. The presence and the grade of subchondral lesions, osteophytes, and cartilage defects were registered.

RESULTS

The kappa values describing the correlation between increased bone uptake and MR detected subchondral lesions varied between 0.79 and 0.49, and between increased bone uptake and MR detected osteophytes or cartilage defects the values were < 0.54. The kappa values describing the correlation between the grade of bone uptake and the grade of the different MR findings was < 0.57.

CONCLUSIONS

Good agreement was found between increased bone uptake and MR detected subchondral lesion. The agreement between increased bone uptake and osteophytes or cartilage defects was in general poor as well as the agreement between the grade of bone uptake and the grade of the MR findings.

New perspectives on osteoarthritis

Osteoarthritis (OA) is the most common rheumatologic disease, afflicting tens of millions of U.S. citizens. It is not an inevitable consequence of aging; rather, it is a degenerative process acquired because of metabolic, mechanical, genetic, and other influences. It is characterized by progressive loss of cartilage and bony overgrowth. Because cartilage is not innervated, the pain of OA arises from secondary effects, such as joint capsule distention, stretching of periosteal nerve endings, and, possibly, synovial inflammation. Psychologic factors, including stress and depression, may influence the perception of pain by OA patients. The risk of OA apparently is not increased by normal joint use, but persons who participate in competitive sports or who play with abnormal or injured joints are at increased risk. Obesity increases OA risk, and weight loss has been found to decrease it. Some forms of premature OA appear to be inherited. The objective diagnosis of OA is made on the basis of radiography. However, many individuals with radiographic evidence of OA are asymptomatic in the affected joint. It is essential to ensure that pain in the affected joint is attributable to OA and not another cause. The management of OA should include physical medicine measures such as heat or cold therapy and often neglected environmental measures, such as reducing chair height and using shoe orthotics. Therapeutic exercise is beneficial for many patients and includes an initial warm-up with range of motion, muscle strengthening, and aerobic activity (such as swimming). A major question in the pharmacologic management of OA is whether nonsteroidal anti-inflammatory drugs (NSAIDs) are superior to analgesics in terms of symptomatic relief; studies indicate that they are not. The question is relevant because of the adverse effects of NSAID use, particularly in the elderly population.

Progression of digital osteoarthritis: a sequential scintigraphic and radiographic study

Hand radiographs and scintigraphy were obtained initially and at the 4-year follow-up in 15 patients with symptomatic osteoarthritis (OA) of distal and/or proximal interphalangeal joints. For each joint, a 0-15 score was obtained for the OA radiographic lesions read blind by the same observer. An abnormal isotope retention over a bone reference area was assessed and quantified. The predictive value of scintigraphy for the OA radiographic progression was confirmed and shown to be improved by a second investigation. During the study period, the percentage of radiographic OA joints increased from 66.3 to 76.6%, but joints showing an abnormal scan decreased from 40 to 22.5%. Progression of the OA radiographic score was closely related to scintigraphic changes. The mean difference between the final and initial OA score was -0.08 in joints with two normal scans (N = 115), +0.73 in joints showing a first abnormal and a second normal scan (N = 94) and +1.8 in joints with two abnormal scans (N = 14) or a scan becoming abnormal (N = 47). An abnormal scan appears to represent a transient event, and this event is associated with a period of progression of digital OA. Potentially, anti-OA therapies that suppress joint isotope retention might slow down OA progression. The magnitude of joint isotope retention was positively correlated with the OA radiographic score established at the same time (R = 0.61 and P < 0.001), but showed no predictive value for progression of the latter.

Scintigraphic assessment of osteoarthritis of the knee joint

Clinical, radiographic, and scintigraphic abnormalities of the knee joint have been correlated in a cross sectional study of 100 patients with osteoarthritis. The group comprised 73 women and 27 men with a mean age of 65.7 years. One hundred and ninety one of the 200 knees had clinical (175) or radiographic (185) evidence of osteoarthritis, or both (161). Scintigraphic images of the knees were obtained 4-5 minutes (early phase) and 2.5-3.5 hours (late phase) after intravenous injection of 600 mBq of technetium-99m diphosphonate. Abnormal images were recorded in 162 knees (81%), and six different patterns were detected. Generalised isotope retention around the knee (early or late phase) was less common than focal areas of uptake around the joint margin (early or late phase) or in the patella or subchondral bone (late phase). Some knees with abnormal scans were normal on radiography (n = 7), or vice versa (n = 21). Different scan patterns correlated with different clinical and radiographic features: the generalised pattern correlated with pain (odds ratio (OR) = 45.1) and osteophytes (OR = 48.3); joint line retention correlated with subchondral bone sclerosis on radiography (OR = 62.1); and subchondral bone retention correlated with more severe radiographic changes. It is concluded that different patterns of scintigraphic abnormality reflect various aspects of the disease process of osteoarthritis.

Comparison of clinical, radionuclide, and radiographic features of osteoarthritis of the hands

Simultaneous clinical, scintigraphic, and macroradiographic assessments were carried out on 32 patients with hand osteoarthritis and the results at entry and one year reported. The presence and growth of osteophyte correlated with symptoms and a positive scan. The scan did not detect the radiographic features of juxta-articular radiolucencies, subchondral sclerosis, or cartilage thinning. Osteophytes, particularly when fast growing, produce pain, a 'hot' scan, and may predict disintegration of joint architecture.

Quantitative imaging of osteoarthritis

Plain-film radiography currently remains the mainstay of imaging for diagnosis and follow-up in osteoarthritis (OA). However, recent studies have questioned some aspects of its use, particularly the correlation between radiographically evident joint-space narrowing and articular cartilage loss. The results with imaging modalities such as magnetic resonance imaging and ultrasound suggest that these methods will allow accurate noninvasive definition of the structure of articular cartilage and other soft tissues of joints. Other modalities, including microfocal radiography and high-resolution computed tomography, can produce detailed images of trabecular structure and bony alterations in osteoarthritis. Improvements in image analysis and data manipulation, including three-dimensional reconstruction and digitized storage and measurement of images, will likely enable improved quantitative assessment of the abnormalities demonstrated by these techniques. One can hope that such developments will facilitate not only improved detection and definition of OA, but also better evaluation of the effectiveness of pharmacological and physical therapy in practice and in clinical trials.

Techetium 99m methylene diphosphonate bone scanning in osteoarthritic hands

In this prospective study, the radiological features characteristic of osteoarthritis of the hand were compared with the radionuclide bone scan images. A total of 32 patients was assessed at 6-monthly intervals for 18 months. Microfocal radiographs were taken at each visit. The high magnification and resolution of this technique permitted direct measurement of joint space width, subchondral sclerosis, osteophyte number and area and juxta-articular radiolucency area for each joint in the hand. Four-hour technetium 99m methylene diphosphonate bone scans were taken at 0 and 12 months and the activity of tracer uptake at each joint scored. The latter was compared with each X-radiographic feature at every visit and the changes between visits analysed. The scan scores did not correlate with any of the X-radiographic features other than osteophyte size. During the study the size of growing and remodelling osteophytes increased significantly at joints with raised or increased isotope uptake.

Some recent clinical approaches to osteoarthritis research

Clinical investigation of osteoarthritis (OA) is the starting point of the "research triangle," leading to appropriate animal and in vitro studies. This article discusses the historical perspective of clinical investigation, definition of OA, case studies taking place in Bristol, assessment and measurement of OA, including imaging of various types and possible biochemical "markers" of the OA process. The different aspects of the process of OA need to be related to outcome, and the future for clinical research in OA is postulated.

Osteoarthritis revisited

Current research challenges the concept that osteoarthritis is an inevitably progressive disease. Evidence suggests that many factors are involved and that the radiological features represent a spectrum of bone and joint response to disease, rather than reflect disease as such.

Inflammatory joint disease: a comparison of liposome scanning, bone scanning, and radiography

Patients with rheumatoid arthritis, psoriatic arthritis, and osteoarthritis were assessed by clinical evaluation, radiography, and joint scintigraphy using technetium labelled methylene diphosphonate (MDP) and technetium labelled liposomes. Although both scanning techniques were more sensitive than radiographs in detecting joint disease, the liposomes scans were positive only in clinically active inflammatory disease. In patients with rheumatoid arthritis liposome scintigraphy was also able to discriminate between different grades of joint tenderness. In inactive inflammatory polyarthropathies, although the MDP bone scans continued to show increased activity, the liposome scans did not and were therefore a more accurate reflection of the clinical state. The increased uptake in the liposome scans may be due to incorporation of the liposomes into the phagocytic cells of the synovium. This scan may, therefore, by reflecting the activity of cells involved in the disease process, provide a useful way of assessing disease activity and progression.

Thermographic and scintigraphic examination of the early phase of inflammatory disease

Modern imaging techniques can be a valuable aid to the rheumatologist. Isotope scans, particularly technetium diphosphonate, can give very early localisation of inflammatory activity. Infra-red thermography can also provide early data, and is completely non-invasive. In drug assessment, thermography is particularly useful, quantifying the anti-inflammatory effects, which may be more rapid in the small joints and slower in joints such as the knee. Given that many anti-inflammatory drugs are analgesic at a low dose yet may improve subjective function e.g. grip test, there is a definite role for objective measurement of true anti-inflammatory effects. The methodology is now well proven and easily used in clinical practice.

99mTc HMDP bone scanning in generalised nodal osteoarthritis. II. The four hour bone scan image predicts radiographic change

In 14 patients with generalised nodal osteoarthritis a four hour bone scan image was found to predict the changes that occur on the radiograph at follow up between three and five years later. The scan abnormality appeared to precede the development of radiographic signs, and joints abnormal on scintigraphy showed most progression. Normal joints and joints abnormal on x ray alone showed little progression, and those that did subsequently alter became abnormal on scan. Scanning may provide a sensitive technique for monitoring osteoarthritis, it may enable a greater understanding of the underlying disease process, and allow evaluation of modifying therapeutic procedures.