JOURNAL OF MIUTflRV PHRRMflCO-MEDKINC N<>7-2014
A CROSS-SECTIONAL STUDY ON MRI CHARACTERISTICS OF SYMPTOMATIC OSTEOARTHRITIS KNEES IN INPATIENTS
AT 103 HOSPITAL
Nguyen Xuan Thiep*; Nguyen Thanh Le**; Nguyen Thi Phi Nga**
Doan Van De**; Le Dinh Tuan***; Tran Viet Tien**
SUMMARY
Background: Doubts have been expressed about the relationship between the seventy of symptoms of osteoarthritis (OA) knees and anatomical changes within involved joints.
Objective: To investigate characteristics of magnetic resonant images (MRI) of heavily symptomatic knees with OA.
Methods: A prospective observational cross-sectional study was conducted on 54 symptomatic knees OA on admission These patients were selected for MRI investigation.
Results. 100% of the patients had cartilaginous defects, 53% had osteochondral defects, 74.1% had bone marrow edemas, 38.5% had subchondral cysts, 74.1% had osteophytes. 100%
had meniscal intrasubstance degeneration, 42.6% had meniscal subluxations, 57.4% had meniscal tears, and 18.5% had portions of menisci loss, 90.7% had synovial effusions or synovitis
Conclusion: Anatomical changes in heavily symptomatic knees with OA are obvious.
• Key word: Symptomatic osteoarthritis knee; MRI.
INTRODUCTION ebumation of subctiondral bone, osteophytes, Osteoarthritis is the most common type ^"^ subchondral cysts. When clinically of arthritis, making up high prevalence, « " " ' ^ * oste°arthntis is characterized by especially in the elderly. It is also the joint pain, tenderness, limitation of movement, leading cause of the high rate of disability "^P^"^' o<:'^si°nal effusion, and variable in the elderly. Aging population and obesity t^^grees of inflammation without systemic are major risk factors of increasing effects [7]. Up to date, many studies have morbidity [4]. OA is characterized by a revealed the ability of MRI in detecting progressive loss of articular cartilage morphological changes frequently occumng accompanied by new bone fomiation and, i" OA which helps physicians not only often, synovial proliferation that may culminate have better understanding of the condition inpain, loss of joint function, and disability b"* also track the efficacy of various [1]. OA is manifested by morphological, treatments. However, there are still a few biochemical, molecular, and biochemical studies on this field conducted in Vietnam changes of both cells and matrix which and we initiated the research with a view lead to a softening, fibrillation, ulceration, to detecting MRI charactehstlc? in symptomatic loss of articular cartilage, sclerosis and knees with OA.
* Military Medicine Department, Bonder Femes
" 103 Hospital
'" Thaibinh Pharmaco-Mediclne University
Corresponding author: Le Dinh Tuan ([email protected])
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JOURNRL OF MILITARV PHflflMRCO-mCDICINE N°7-2014 SUBJECTS AND METHODS
A pnsspective otisen/ational cross-sectional study was carried out on 32 patients aged
> 38 years between December, 2012 and July, 2013 diagnosed with knee OA unilaterally or bilaterally on admission. The disease situation was clinically assessed based on standardized protocols by research therapists. All participants underwent an antero-posterior and a lateral plain radiography of their both knees. These radiographs were scored later by a radiologist blinded to clinical status Information from both teams was collected to choose 54 knees for later MRI invesfigation.
* Selection criteria:
- Symptomatic knees that fulfilled the American College of Rheumatology (ACR, 1991) Clinical Classification Criteria for Osteoarthritis of the Knee [2] were selected.
The following symptoms and signs were evaluated; unilateral or bilateral knee pain (1); marginal osteophytes in plain radiographs (2): morning stiffness < 30 minutes (3);
crepitus (4); age £ 38 (5); articular fluid (if presented) had cell count < 2,000/mm' (6). The knees were selected if they had (1) + (2) or had at least 4 out of the 6 symptoms and signs mentioned with (1), (3) and (4) were mandatory.
- The patients were willing to enroll in the research
* Exclusion criteria:
- Knees with history of infections, rheumatism, gout, trans-articular wounds/
fractures.
- Patients that could not undertake an MRI procedure (bearing pacemakers, metal pieces, claustrophobia).
* MR/ acquisition:
The 54 selected knees were imaged in a 1.5T superconducting magnet (Philips
Medical Systems) using a dedicated knee coll at the Diagnostic Imaging Department of Hospital 103. Every examination consisted of:
- Coronal proton density and T2-weighted dual spin echo (SE), 5 mm slice thickness.
- Sagittal proton density and T2-weighted dual SE images, 5 mm slice thickness
- Sagittal three-dimensional (3D) T1- weighted spoiled gradient echo (GE) frequency selective fat-suppressed images, 1.5 mm slice thickness; no gap.
- Axial proton density and T2-weighted turbo spin echo (TSE) fat-suppressed images, echo tram length 6; 2 mm slice thickness; no gap.
Total acquisition time was 30 minutes (including the initial survey sequence)
MRIs were scored according to KOSS (Knee Osteoarthritis Scoring System) [8].
Cartilaginous and osteochondral defects, osteophytes, subchondral cysts and bone marrow edema were assigned to the following anatomical locations;
- The patellar crest (crista patellae).
- Medial or lateral patellar facet.
The medial or lateral trochlear articular facet.
- The medial or lateral femoral condyle (excluding the trochlear groove).
- The medial or lateral tibial plateau.
The medial and lateral meniscal horns were reviewed for the presence of meniscal tears, subluxation, intrasubstance degeneration or absence of a meniscal portion. A meniscal abnormality was assigned to the body, the anterior or posterior horn.
Joint effusion, synovitis and Baker's cysts were noted.
MRIs were interpreted by a 10-year experienced radiologist on MRI.
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JOURNfll OF MIUTRRV PHRRMRCO-MEDICINC N°7-2014 RESULTS
1. Descriptive characteristics.
Table 1: Descriptive characteristics of 32 participants.
FEATURES
Age
Gender
<40 4 0 - 5 9
>59 Male Female
NUMBER (total = 32) 2 7 23 17 15
PROPORTION (%) 6.3 21.8 71 9 53.1 46.9 The table showed that patients over 59
years accounted for the highest percentage (71.9%). However, there was a balance in the gender.
2. MRI characteristics.
* Prevalence of lesion in categories:
Cartilaginous defect: 54 knees (100%);
bone marrow edema: 40 knees (74,1%), osteochondral defect; 32 knees (59,3%);
osteophyte: 40 knees (74,1%); meniscal lesion: 54 knees (100%); synovial effusion:
49 knees (90,7%).
in an overview of lesions prevalence in different categories, it was shown that hyaiine cartilaginous defects and meniscal lesions were observed in all inspected knees. Osteochondral defects were the least common and only presented in 59.3% of investigated knees.
Table 2: Cartilaginous defect characteristics.
LOCATION OF CARTILAGINOUS DEFECT Patellar crest Medial patellar facet Lateral patellar facet Medial trochlear articular facet Lateral trochlear articular facet Medial femoral condyle Lateral femoral condyle Medial tibial plateau Lateral tibial plateau
GRADE 1 (n; %) 0 (0.0) 3 (5.6) 3 (5.6) 2 (3.7) 4(7.4) 5 (9.3) 12 (22.2)
0 (0.0) 2 (3.7)
GRADE 2 (n;%) 9 (16.7)
5 (9.3) 7 (13.0) 3 (5.6) 5 (9.3) 27 (50-0) 30 (55.6) 5 (9.3) 1 (1.9)
GRADE 3 (n; %) 20 (37.0) 15(27.8) 14 (25.9) 8(14 8) 9(16 7) 20 (37.0) 7(13.0) 9 (16.7) 2(3.7)
TOTAL (n; %) 29 (53.7) 23 (42.6) 24 (44.4) 13(24.1) 18(33.3) 52 (96.0) 49(91.0) 14(25.9) 5(9 3)
Cartilaginous were divided into depth as deflned were also seen in as shown In table was the most defects (96.0%);
observed in 20
defects, in particular, three grades due to their by KOSS. These lesions their anatomical locations 2. Medial femoral condyle frequently cartilaginous defects > grade 2 were inspected knees (37%).
Patella was also a lesion of high frequency detected at grades 2 and 3.
Lateral femoral condyles, in comparison to medial ones, had a slightly smaller frequency of cartilaginous defects (91.0%) and this lesion was also less severe.
Significant cartilaginous defect (> grade 1) was only seen in 37 knees (68.5%).
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JOURNRL OF MILITRRV PHRRMRCO-MCDICINE N°7-Z014 TaWe 3; Osteochondral defect characteristics.
LOCATION OF OSTEOCHONDRAL DEFECT Patellar crest Medial patellar facet Lateral patellar facet Medial troctilear articular facet Lateral trochlear articular facet Medial femoral condyle Lateral femoral condyle Medial tibial plateau Lateral tibial plateau
GRADE 1 (n; %) 6(11.1) 8 (14.8) 10 (18.5) 1 (1.9) 4 (7.4) 11 (20.4)
3 (5.6) 5 (9.3) 0 (0.0)
GRADE 2 (n: %) 2 (3.7) 1 (1.9) 1(1.9) 5 (9.3) 5 (9.3) 5 (9.3) 1 (1.9) 4 (7.4) 1 (1.9)
GRADES (n;%) 0 (O.D) 0 (0.0) 0 (0.0) 1 (1.9) 1 (1.9) 1 (1.9) 0 (0.0) 0(0.0) 1 (1.9)
TOTAL (n; %) 8 (14.8) 9(16.7) 11 (20.4)
7 (13.0) 10 (18.5) 17(31.5) 4(7 4) 9 (16.7) 2 (3,7) Osteochondral defects had the greatest frequency of occurrence in medial femoral condyles (31.5%). 20.4% of knees with osteochondral defects were detected in lateral patellar facets, ranking the second only alter medial femoral condyles.
Table 4: Bone marrow edema characteristics.
LOCATION OF LESION Patellar bone Femoral bone Tibial bone
TaWe 5.- Osteophyte LOCATION OF LESION Patellar bone Femoral bone Tibial bone
GRADE 1 (re %) 9(16.7) 14 (25.9) 13 (24.1)
;haracteristics.
GRADE 1 (re %) 14 (25.9) 11(20.4) 16(29.6)
GRADE 2 (n: %) 5 (9.3) 18 (33.3) 6(11,1)
GRADE 2 (n; %) 9 (16.7)
4 ( 7 4) 8 (14.8)
GRADE 3 (n; %) 0 (0.0) 1 (1.9) 2 (3,7)
GRADES (n; %) 2 (3.7) 13 (24 1)
3 ( 5 6)
TOTAL (re %) 14 (26.0) 33(61.1) 21 (38.9)
TOTAL (n; %) 25 (46.3) 28(51.9) 27 (60,0) In the research, bone marrow edemas and osteophytes were relatively equal (74.1%) as shown in table 4 and 5. Both lesions were the most frequently common in femoral bones.
TaWe 6; Subchondral cyst characteristics.
LOCATION OF LESION Patella
Femoral bone Tibial bone
GRADE 1 (n; %) 2(3.7) 3 (5.6) 1 (1.9)
GRADE 2 (n, %) 3 (5.6) 8(14.8) 3 (5.6)
GRADE'S (n;%) 1 (1.9) 5 (9.3) 2 (3.7)
TOTAL (n; %) 6(11.2) 16 (29.7) 6(11.2) Femoral bones had the highest frequency and the greatest diameter of both subchondral cysts and osteophytes.
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JOURNfll OF MILITflRV PHflRMRCO-MCDICINC N ° 7 - ! 0 1 4 Table 7: Meniscal lesion characteristics.
PORTION OF MENISCUS
Medial meniscus
Lateral meniscus
Anterior horn Posterior tiom Body Anterior hom Posterior hom Body
TEAR (n; %) 3 (5.6) 7(13.0) 4 (7.4) 6(11.1) 2(3.7) 6(11.1)
SUBLUXATION (re%) 11 (20.4)
1 (1.9) 14(25.9) 2(3.7) 0 (0.0) 3 (5.6)
DEGENERATION (n; %) 47 (87.0) 50 (92.6) 46 (85.2) 44(81.5) 53 (98.1) 45 (83.3)
ABSENCE (n; %) 0 (0.0) 3 (5.6) 1 (1.9) 4 (7.4) 0 (0.0) 2 (3.7) 100% of investigated knees had a manifestation of meniscal intrasubstance degeneration at least in one of their anatomical portions. Meniscal subluxation were seen in 31 knees (57.4%), meniscal tears occurred in 30 knees (55,6%), but only 10 knees (18,5%) were absent from the portions of meniscus.
TaWe 8: Effusions/synovitis in particular recesses.
RECESS Suprapatellar pouch Medial patellar recess Lateral patellar recess Dorsal femorotlbjal joint space Popliteal tendon sheath Surrounding antenor cruciate ligament Sunounding posterior cruciate ligament Menlscosynovial recess
Baker cyst 1 lecess presentation 2 recess presentation
> 2 recesses presentation
NUMBER (n = 54) 32 40 20 9 7 1 6 2 5 10 12 27
PROPORTION (%) 59.3 74.1 37.0 16.7 13 1.9 11.1 3.7 9.3 18.5 22.2 50 0 Synovial fluid images were noticed in 49 knees (90.7%). 5 knees showed no sign of fluid (9.3%). 27 knees (50%) with fluid images were seen in more than 2 recesses presentation. Fluid images were mostly observed around patellae (83.3%) with the proportion of occurring in suprapatellar pouches alone was 59%.
TaWe 9: Total scores by KOSS.
SCORE
<47 2 47 Average
NUMBER (n = 54) 26 28
PROPORTION (%) 48.2 51.9 47.19 (±22.045)
With a total of 54 knees with OA investigated with MRI and scored by KOSS, the highest score was 91 and the lowest was 13.
97
JOURNRl OF MIUTflRV PHRRMRCO-MCDICINC N°7-!aU DISCUSSION
MRI has been a popular imaging diagnostic technique in recent years.
Differences in the density of protons and other magnetic resonant capable atomic nuclei in different tissues enable this technique to gain pictures with good contrast even If those adjacent tissues are similar in echogenicity or opacity. Together with stronger magnetic field and faster computing, the advents of new contrast agents has yielded better resolution and contrast.
In this study, all the MRI inspected knees were clinically and radiographically diagnosed with OA. The results showed that cartilaginous defect, the very first lesions of OA were all manifested in at least one of their anatomical locations.
Most severe cartilaginous defects were observed in medial femoral - tibial joints.
Cartilaginous facets in this joint seem to be the most stressful loaded in human activities. Cartilaginous defects, joint space narrowing in this compartment cause varus alignment that shifts the load-bearing axis medial to knee center, creating a moment arm that increases forces across the medial compartment which can quicken the OA progression [3). To compare between medial and lateral femora-tibial compartments, 4 8 . 1 % of knees with cartilaginous defects had more severe in medial space while only 9.3% of this lesion was more severe in lateral space.
Beside two mentioned defects, patellar cartilaginous facets and their counterparts in trochlear grooves were also the severe cartilaginous ones. In the study, there were 8 knees (14.8%), of which cartilaginous and osteochondral defects in patellar-
femoral compartment signiflcantly out- weighed over those lesions in femoral- tibial ones. Hinman and K. M. Crossley (2007) supposed that patellar-femoral joint OA and femoral-tibial joint OA are distinct entities which require distinct approaches [6].
32 out of 54 knees (59.3%) presented osteochondral defects in at least one of their anatomical locations. Similar to the defects of cartilage, the locations of osteochondral defect commonly occurs In the medial femoral condyles and medial tibial plateaus and lesions in this locations were often more severe. The facets of trochlear grooves were the places of moderate osteochondral defects. Lateral femoral-tibial compartments, in comparison with the other two compartments belonging to the medial femoral-tibial and patellar- femoral regions, were the least commonly seen region of osteochondral defects and lesions in this area, when presented, were also less severe. Bone marrow edema was observed in 74.1% of Inspected knees with the most frequent occurrence in femoral bones. This lesion was also seen in tibial bones with various grades of severity. Subchondral cysts were less common than bone marrow edemas but usually appear together with the latter (p < 0.05). In the current research, subchondral cysts were seen in various forms and sizes with the most common location of femoral bones, followed by the tibial bones and patellae with equal frequencies (table 6). Osteophyte's appearances on MRIs were much different from that on plain radiographs and could be detected in more shapes and places.
Many "osteophytes" developed so large
JOURNRl OF MILITflRV PHRRMflCO-MCDICINC N°7-2ai4 that it tiecame 'banks" of bone, embanked
their bones of origins. In our research, many trochlear grooves had two walls, ones of origin and the others outer was newly built by "osteophytes" if they could still be named like that.
Lesions of menisci appeared on MRIs were also various. Meniscal intrasubstance degenerations were the most common encountered with various grades. Meniscal tears were more clearly to be seen if being vertical, horizontal or complex but more difficult if radial, in the research, 57.4% of knees had meniscal tears, 42.6%
had meniscal subluxation, and 18.5% had some of their meniscal portions loss.
Water has a plenty of protons so edematous synovitis and synovial effusions are readily to be seen on MRIs, However, heavy edemas make it difBcult to differentiate images of synovitis from those of effusions.
Contrast agents must be used for the certain of the differentiation between these two entities. These agents, after given intravenously, will be able to appear in the capillaries of synovial membranes but not the synovial recesses thus enable us to tell the actual places of the water. In our research we did not use contrast agents and had to describe these two entitles with the same term of "fluid image". They were only absent at all recesses in 9.3%
of knees while presented at more than 2 recesses In 50% of cases. In our research. Baker's cysts presented with 9.3% of knees. In another research, Binh Thi Dieu Hang [5] only detected this cysts in 1.4% of inspected knees which was also with OA. This large difference of proportions may be due to methods of detection. The above author attempted to detect these cysts by palpation and this
method is much less sensitive to effusion when compared to MRI.
MRI is regarded as one of the most useful noninvasive tools for detecting great details of various lesions of knee OA. Like many other degenerative diseases, knee OA progresses continuously with aging but not always is symptomatic. In the research, many newly symptomatic OA knees had quite severe lesions revealed by MRI 12 knees with only mild pains (WOMAC pain scores s 10) and little radiographic lesions (Kellgren-Laurence scores < 2) were selected to assess their MRIs, the results was that anatomical lesions were still obvious enough with the average KOSS scores of 24.5 (±18.3), Many authors suppose that MRI can detect knees with OA in their very early stages even those are asymptomatic and this technique should be used to screen those at high risk of developing OA.
Changing life styles, works, exercise methods, etc properly in time may restrain the disease. Symptoms of OA may fluctuate rapidly due to many factors while anatomical lesions were worse or better and reflect the actual acts of both disease processes as well as therapeutic attempts and can be used as an efficient tool in assessing new treatments aiming at anatomical targets. Sharing this opinion, in 2011, after a study aimed at Identifying predictive factors for total knee replacement using data from MRI of knee osteoarthritis patients in a phase 111 multicentre disease-modifying osteoarthritis drug (DMOAD) study [9] Jean-Pierre Raynauld supposed that MRI could be used to Identify risk factors of later progressive knee OA and deflne the outcome of trial DMOADs.
JOURNfll OF MIUTHRV PHflRMflCO-MCDICINC N°7-2014 CONCLUSION
With 54 symptomatic knees that fulfilled ACR Clinical Classiflcation Criteria for Osteoarthritis of the Knee examined by MRI we draw the following conclusion;
-100% of knees with OA had cartilaginous defects in at least one anatomical location with medial femoral condyles the most Involved (96%).
- 53% had osteochondral defects in at least one anatomical location, 74.1% had bone marrow edemas, 38.5% had subchondral cysts, 74.1% had osteophytes
- 100% had signs of Intrasubstance degeneration of their menisci, 42.6% had meniscal subluxations, 57.4% had meniscal tears, and 18.5% had some portions of their menisci absent
- 90.7% had synovial effusions or synovitis among which 18% had 1 recess involved.
22.2% had 2 recesses involved, and 50%
had more than 2 recesses.
REFFERENCES
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Arthritis Res Ther. 2009, pp.11-227.
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4. Leena Sharma. Jlng Song et al. Vanjs and valgus alignment and incident and progressive knee osteoarthritis. Ann Rheum Dis. 2010, 69, pp.1940-1945.
5. Harhson's Pnnclpies of Intemal Medicine 18th edition. Part 14, Section 3. Chapter 332, Osteoarthritis The McGraw-Hill Companies. 2012,
6. Hinman and K. M. Crossley Patellofemoral joint osteoarthritis: an important subgroup of knee osteoarthritis. Rheumatology. 2007, 46, pp,1057-1062,
7. Klaus E. Kuettner, Victor M. Goldberg, eds American Academy of Orthopaedic Surgeons.
June 1995. Osteoarthritic Disorders; Wort(Shop, Monterey, California, April 1995.
8. Peter R et al MRI assessment of knee osteoarthritis; Knee osteoarthritis scoring system (KOSS)-inter-observer and intra-obsen/er repriDducibility of a compartment-based scoring system. Skeletal Radiol. 2006, 34, pp.95-102.
9. Jean-Pierre Raynauld et al for the Canadian Licofelone Study Group. Risk factors predictive of joint replacement in a 2-year multicentre clinical trial in knee osteoarthritis using MRI; results from over 6 years of observation. Ann Rheum Dis. 2011, 70, PP.1382-13B8.
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