Med. J. Cairo Univ., Vol. 84, No. 3, December: 97-, www.medicaljournalofcairouniversity.net A Comparative Study of Ultrasonographic Findings with Clinical and Radiological Findings of Painful Osteoarthritis of the Knee Joint HALA H. ABD EL-MAKSOUD, M.D.* and AMR M. GAMEIL, M.Sc.** The Departments of Rheumatology & Rehabilitation* and Radiology**, National Institute of Neuromotor Rehabilitation, General Organization for Teaching Hospitals and Institutes, Egypt Abstract Aim: To evaluate correlation between ultrasonographicsynovitis, effusion and clinical and radiological parameters in patients with painfull osteoarthritis of the knee joint. Patients and Methods: 5 patients with primary chronic painfull knee osteoarthritis (5 knee joints) fulfill (ACR criteria) with pain during physical activity 3mm. On VAS, other clinical parameters [synovitis and effusion (moderatesevere, absent-minimal)] on clinical examination, plain x- may of knee joint (kellgrenlawrence grade: -4) were collected. Ultrasonographic examination of the painfull knee was performed by radiologist in the same day. Ultrasonographicsynovitis was defined as synovial thickness >_4mm with diffuse or nodular appearance, and joint effusion was defined as effusion depth 4mm. Results: 5 patients with 5 painful knee OA were analysed. At US (4%) demonstrated neither synovitis nor effusion, (48%) had effusion alone, (8%) had both synovitis and effusion and (4%) had synovitis alone. Multivariant analysis showed that inflammation and effusion seen by US hadnon significant statistical correlation with advanced radiological disease (kellgren-lawrence grade 3, p-value=.957 for synovitis and odd ratio=. for joint effusion), with knee joint effusion on clinical examination (p-value=.9999 for synovitis and effusion) and with pain intensity on activity (p-value=.47 for synovitis and odd ratio=4.875 for effusion). Conclusion: Ultrasonographic synovitis and effusion had non significant statistical correlation with either clinical or radiological parameters suggestive of inflammation. Key Words: Ultrasonography Synovitis Effusion Osteoarthritis. Correspondence to: Dr. Hala H. Abd El-Maksoud, The Department of Rheumatology & Rehabilitation, National Institute of Neuromotor Rehabilitation, General Organization for Teaching Hospitals and Institutes, Egypt Introduction PAIN is the predominant feature of clinical knee osteoarthritis, but its origin is not clearly established []. Among the different tissues contributing to the sources of pain, synovial tissue or subcondral bone, or both may have an important role []. A link between synovial inflammation and progression of structural damage has been suggested by a number of studies. The clinical diagnosis of synovial inflammation in knee osteoarthritis based on the presence of symptoms such as a sudden change in the level of pain, pain at night, prolonged morning stiffness and the presence of an effusion on clinical examination [3]. A more objective assessment of inflammatory findings in osteoarthritis might be obtained by imaging techniques such as arthroscopy, MRI or Ultrasonography. Ultrasonography seems more useful in the evaluation of joint effusion and synovitis (both hypertrophy and morphology) [4,5]. Aim of work: Evaluate correlation between US synovitis and joint effusion and between these two variables and clinical features and X-ray grading of OA of knee. Patients and Methods The study was conducted on 5 patients with primary osteoarthritis who attend outpatient clinic of Rheumatology in National Institute of Neuromotor Rehabilitation from June -August. 97
98 A Comparative Study of Ultrasonographic Findings 5 outpatients with chronic, painfull, primary knee osteoarthritis who attend outpatient clinic of Rheumatology and Rehabilitation in National Institute of Neuromotor Rehabilitation. Permission from Ethics Committee of General Organization for Teaching Hospitals & Institutes was obtained and a written informed consent was obtained from every patient before study participation. They were 4 females and one male with age group ranged between 3-7 years. Inclusion criteria: All patients with primary knee osteoarthritis according to the American College of Rheumatology [] with first OA symptoms detected at least months before study entry, with radiographic evidence of OA for the studied knee defined by kellgren and Lawrence (K & L) grade -4 [7]. And with pain intensity during physical activity 3mm on a cm Visual Analogue Scale (VAS). Exclusion criteria: Disabling OA. Secondary OA. History of injury to the studied knee in the months before study entry. Partial or total knee replacement. Osteotomy of studied joint. History of arthroscopy of the studied joint within the previous year. Intra-articular injection of steroids given during the previous 4 weeks. History of radiographic features of crystalopathies such as gout, etc. Clinical evaluation: Demographic data were collected including age and gender and the presence of clinical effusion (moderate-severe or absent-minimal and synovitis (absent or present). After making the initial diagnosis and selecting the patients that met the criterion to be enrolled in the study, the results of clinical evaluation about presence or absence of synovitis and effusion were recorded. Ultrasound assessment: The ultrasonographic examination was performed by radiologist. The radiologist was blind to the clinical evaluation results. The ultrasonographic features of inflammation in the joint include: Joint effusion, synovial thickening and the presence of vascular flow in synovial tissue in doppler imaging. For all patients a standard protocol was used, with the patient in supine position the knee was evaluated in semiflexed (3-45º) and fully extended position and the suprapatellar pouch was evaluated in the longitudinal and transverse planes (including medial and lateral recesses). Synovitis and effusion were measured and recorded only in the suprapatellar recess using US equipment with a high frequency linear array transducer (8/7MHZ). The maximal synovial thickness and effusion depth were measured in millimeters using longitudinal axis. The following features were recorded: Synovitis was defined as hypoechoic synovial hypertrophy with thickness 4mm. The shape of synovial hypertrophy was also marked as diffuse or nodular appearance with the knee semiflexed at 45º on the median longitudinal plane crossing the quadriceps tendon. It was recorded as absent if maximal synovial thickness was >4mm and present if 4mm [8]. Effusion: Was defined as an anechoic area and was measured in the suprapatellar recess, with the knee in full extension and measured at the maximum depth observed with a longitudinal scan. It was recorded as absent if the maximal effusion depth was >4mm, and present if 4mm [8]. Results 5 patients analyzed in the study: - Clinical and radiological study (Table ). - Among 5 studied patients with painfull knee osteoarthritis: (4%) demonstrated neither ultrasonographic thickness nor effusion, 4 (5%) had effusion and 3 (%) had synovial thickness. In all 3 cases of synovial thickness the appearance of synovial tissue was diffuse (Table ).
Hala H. Abd El-Maksoud & Amr M. Gameil 99 Table (): Summarizes the main baseline characteristics of the 5 analyzed subjects with painfull knee osteoarthritis. Characteristics Age: Sex: Female, n (%) Male, n (%) Knee pain intensity on VAS, n (%): 9-mm. (Hurts worst) 7-8mm. (Hurts whole lot) mm. (Hurts even more) Knee joint effusion on clinical examination, n (%): Moderate-important Absent-minimal Knee joint synovitis on clinical examination, n (%): K & L radiological grade 3, n (%) K & L radiological grade >3, n (%) Subjects n=5 Range: 3-7 years old. Mean: 5.7 SD:. 4 (9%) (4%) 4 (%) (4%) (44%) (8%) 3 (9%) (%) (48%) 3 (5%) K & L radiological grade 3 in medial femorotibial compartment & or in femoropatellar comportment of the studied knee. Table (): Ultrasonographic distribution of synovial thickness, synovial appearance as well as maximal knee joint effusion depth. Absent Present Synovial thickness (mm): (88 %) 3 (%) Mean (SD).98 (.8) Median (range).4 (4.4) Appearance of synovial tissue, n (%): Normal appearance 8 (7%) (%) Nodular 3 (%) (%) Diffuse (4%) 3 (%) Maximal effusion depth (mm): (44%) 4 (5%) Mean (SD) 4.8 (.) Median (range) 4. (8.7) US knee synovitis was defined as "present" if synovial thickness was 4mm with diffuse or nodular appearance. US knee effusion was defined as "present" if maximal effusion depth was 4mm. Table (3): Comparison between ultrasonographic synovial thickness and clinical and radiological characteristics in subjects with painfull knee osteoarthritis. Characteristics US synovial thickness Absent n (%) Present n (%) p-value (fisher exact test) VAS: 7-mm. (Hurts whole 9 (7%) (8%).47 lot & hurts worst) ( (NS) mm. (hurts even more) 3 (%) (4%) (4 Effusion on clinical examination: Moderate-severe ( (8%) (%).9999 Absent-minimal (3 (8%) 3 (%) (NS) Radiological K & L grades: 3-4 ( 9 (3%) 3 (%).957 - (3 3 (5%) ( %) (NS) NS: Statistically nonsignificant difference between two groups subjects with knee OA with a more severe pain intensity on VAS 7mm. (Hurts whole lot "7-8mm." & hurts worst "9-mm."), a more severe radiological grade (K & L grade 3) and moderate or important knee joint effusion on clinical examination had no increased probability of synovial thickness being detected on US examination (p-value on fisher exact test: Non-significant:.47,.9999 &.957 respectively). Table (4): Comparison between ultrasonographic knee joint effusion and clinical and radiological characteristics in subjects with painfull knee osteoarthritis. Characteristics VAS: 7-mm. (Hurts 8 (3 whole lot & hurts worst) ( mm. (hurts even 3 (%) more) (4 Us knee joint effusion Absent Present n (%) n (%) p- value O.R. (95% CI) %) 3 (5%). 4.875 (NS) (.498 to (4%) 55.94) Radiological K & L grades: 3-4 ( 5 (%) 7 (8%).84. - (3 (4%) 7 (8%) (NS) (.44 to Effusion on clinical 5.844) examination: Moderate- (4%) (4%) p-value fisher important ( Absent-minimal (3 exact test (4%) 3 (5%).9999 (NS) OR: Odd Ratio. 95% CI: 95% confidence interval. Analyzing the probability of the presence of joint effusion on US in group with VAS 7mm. versus >7mm, K & L 3 versus >3, moderate-important joint effusion on clinical examination versus absent-minimal. NS: Non-significant difference between two groups. Subject with Knee OA with a more servere VAS 7mm, a more severe radiological grade (K & L 3 grade) and moderate or important knee joint effusion on clinical examination had no increased probability of detectable joint effusion on US examination OR (4.87,. "pvalue. Ns:. &.84" & p-value on fisher exact test.9999 "NS" respectively).
A Comparative Study of Ultrasonographic Findings Synovial thickness (mm) Interval.5- -.5.5- -.5.5-3 3-3.5 3.5-4 4-4.5 4.5-5 5 or more Number Synovial thickness Percent 8.% 44.% 4.%.% 4.%.% 8.%.% 4.% 8.% Synovial thickness Mean Std. Deviation Minimum Maximum Range Median Interquartile range mm.98.8. 5. 4.4.4. Effusion depth (mm) 8 4 Relationship between ultrasonographic knee synovial thickness & effusion depth (using linear regression) y=.5743 x + 3.3 r=.34 Number of cases 8 4 Ultrasonographic distribution of synovial thickness -.5.5- -.5.5-3-.5 3.5-3 4-3.5 4.5-4 5-4.5 Synovial thickness intervals (mm) 5 or more Fig. (): Distribution of ultrasonographic synovial thickness in the overall group of patients. 3 4 5 Synovial thickness (mm) Fig. (3): Relationship between ultrasonographic synovial thickness and effusion using actual measurements rather than the predefined protocol cutoff points using linear regression, demonstrated, an intermediate positive relationship. Regression equation Effusion depth =.5743 synovial thickness + 3.3 Effusion depth (mm) Effusion depth Effusion depth (mm) Interval.-..-4. 4.-..-8. More than 8 Number Percent 4.% 4.% 4.% 8.% 8.% Mean Std. Deviation Minimum Maximum Range Median Interquartile range 4.8..8.5 8.7 4..95 (A) Number of cases 8 4 Ultrasonographic distribution of effusion depth.-..-4. 4.-..-8. More than 8 Effusion depth interval (mm) Fig. (): Distribution of ultrasonographic effusion in the overall group of patients. (B) Fig. (4): Synovitis (A) and joint effusion (B) on ultrasonography in subjects with painfull knee OA. (A) Synovitis in a longitudinal scan (suprapatellar recess). (B) Joint effusion in a longitudinal scan (suprapatellar recess).
Hala H. Abd El-Maksoud & Amr M. Gameil Discussion Pain is the prominent feature of osteoarthritis of knee joint and has complex etiologies that are not yet fully understood. It remains uncertain which part of pain in knee OA is explained by the pathology of soft tissue structures. The aim of this study was to evaluate correlation between ultrasonographicsynovitis, effusion and clinical and radiological parameters. Our results found that US inflammation was detected in at least half the subjects with chronic symptomatic knee OA. This study showed a statistically non-significant correlation between ultrasonographic features of inflammation of osteoarthritic knee joint (synovial thickness and effusion) and clinical parameters (pain intensity assessed by VAS mm, effusion on clinical examination and advanced X-ray grades by K & L scale), and lack of sensitivity of clinical parameters in predicting inflammation of the synovium. Our findings are in line with Karen bevers et al., study findings [9] revelaed inability to demonstrate an association between US features and level or degree of knee pain, univariant regression analysis showed no association between separate ultrasonographic features and NRS pain or koos pain scores. Regression analysis in the separate K-L groups, showed no association between US and pain. They explain this by other origin of pain which can not be captured by ultrasonographic features (e.g. bone marrow lesions or locoregional pain). Our results are in line with D'Agostino et al., study results [8] found no significant statistical correlation between US inflammatory signs and pain intensity during physical activity. One of theirexplanationwas that the study focused on the assessment of synovial features alone in painfull knee OA and we did not explore other possible sources of pain and certainly this supports recent MRI studies which suggest that non synovial features such as bone marrow lesions may be associated with pain. Our results disagree with D'Agostino et al., results [8] found that "subjects with knee O.A. with more severe radiological grade measured by K & L grades (K & L 3) and moderate or important knee joint effusion on clinical examination had increased probability of a joint effusion being detected at US examination (OR:.9 and.7 respectively) and an increased probability of synovitis being detected at US examination (OR:. and.97 respectively). Our results are not in line with Bita Abbasi et al., study [] that revealed a positive correlation between US knee arthritis (defined as presence of synovitisor effusion) and WOMAC pain subscore (p>. ). Conclusion: In our study we were unable to demonstrate statistically significant association between ultrasonographic features of inflammation of painful osteoarthritic knee joint (synovial thickness and effusion) and intensity of pain during physical activity, severity of X-ray grades and effusion on clinical examination. References - CREAMER P., HUNT M. and DIEPPE P.: Pain mechanism in osteoarthritis of the knee: Effect of intra-articular anaethetic. J. Rheumatol., 3: 3-, 99. - AMOR B.: Congestive outbreak of osteoarthritis chondrolysis and cartilage repair. Revpart, 43: -3, 993. 3- DOUGADOS M.: Clinical assessment of osteoarthritis in clinical trials. Curt. Opin. Rheumatol., 7: 87-9, 995. 4- KANE D., BALINT P.V. and STURROCK R.D. : Ultrasonography is superior to clinical examination in the detection and localization of knee joint effusion in rheumatoid arthritis. J. Rheumatol., 3: 9-7,3. 5- WALTER M., HARMS H., KNEE V., RADKE S., FAEN- DRICH T.P. and GOHLKE B.F.: Correlation by of power Doppler sonography (PDS) in the diagnosis of synovial hypertrophy of the knee joint by verifying and comparing the PDS findings with histopathological findings of synovial membrane vascularity. Arthritis. Rheum., 44: 33-8,. - ALTMAN R., ASCH E., BLOCH D., BOLE G., BOREN- STIEN K., BRANDT 5.K., et al.: Development of criteria for the classification and reporting of osteoarthritis. Classification of osteoarthritis of the knee. Arthritis Rheum., 9: 39-49, 98. 7- KELLGREN J.H. and LAWRENCE J.S.: Radiological assessment of osteoarthritis of the knee. Ann. Rheum. Dis., : 494-5, 957. 8- DAGOSTINO M.A., CONAGHAN P., LE5BARS M., et al.: Eular report on the use of ultrasonography in painfull knee osteoarthritis. Part : Prevalence of inflammation in osteoarthritis. Ann. Rheum. Dis., 4: 73-9, 5.
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