Articular Cartilage Injury Diagnosis & Classification Dr. Vipul Vijay MBBS MS DNB DipSICOT Att. Consultant, Indraprastha Apollo Hospitals, New Delhi

Tire Analogy Tread of a tire = articular cartilage

Degenerative

Traumatic

Bad to the Bone

History Type of injury Timing of injury Location Duration of symptoms

Symptoms Retro-patellar/peri- patellar pain. Pain in popliteal fossa – in lesions of the trochlea. Pain usually secondary to capsular/synovial irritation sub-chondral bone overload Locking Clicking Feeling of giving way Activity related knee swelling Increased pain with prolonged flexed knee position and stair climbing

Examination ROM Joint swelling Joint line tenderness Gait analysis, to assess Intoeing Hip abductor weakness Valgus mal-alignment of the limb (these predispose knee to injury and alters PF joint biomechanics) Palpation of medial & lateral patellar retinaculum for tenderness Patellar mobility, tilt & subluxation in ML plane Quadriceps wasting especially of VMO

Examination Q angle Should be measured in both extension and 300 flexion laterally subluxed patella in full extension can falsely decrease the Q-angle Patella should be repositioned in the central sulcus before measuring the Q-angle J-sign Patient slowly extends knee from full flexion, patella subluxe laterally once it leaves the constraints of trochlear groove near full extension (may suggest patho laxity of the medial soft tissues, specially the MPFL)

Imaging Radiographs *Standing anteroposterior (AP) *45° flexion posteroanterior (PA “Rosenberg”) *Flexion lateral *Shallow angle axial (Merchant) *Long leg axial True lateral radiograph useful in assessing trochlear dysplasia Patellar tilt not always appreciated on Merchant view

X-rays

Imaging CT of the patello-femoral joint Tibial tubercle to trochlear groove (TT-TG distance) -superposition of two CT images, one through the patello-femoral articulation, the other through the tibial tubercle -calculate the distance between the centre of the TG and the centre of the TT are marked, and medial-to-lateral distance between two is measured - 15 mm normal - >20 mm, consider tibial tubercle osteotomy

Imaging Magnetic resonance imaging Arthroscopy - gold standard for - 100% sensitivity and 81.5% specificity - Allows staging of chondral lesions - May detect very early intra cartilaginous lesions - PD and T2 images are useful Arthroscopy - gold standard for assessing articular injury

Imaging of articular cartilage - MRI Accurate assessment of cartilage thickness Demonstrate changes of cartilage surface Demonstrate changes in internal cartilage signal intensity Allow evaluation of sub-chondral bone for signal intensity abnormalities

Imaging of articular cartilage - MRI Standard techniques FSE / TSE SPOILED GRE IMAGES DRIVEN EQUILIBRIUM FOURIER TR. STEADY STATE FREE PRECESSION Physiologic imaging T2 MAPPING Na+ IMAGING DIFFUSION WEIGHTED IMAGING CONTRAST ENHANCED IMAGING

MRI – cartilage lesions T1 WI FSE T2 – Fat Sat

FSE T2 WI FSE T2 Fat Sat FSE PD Fat Sat 3D SPGRE Fat Sat

recalled gradient acquisition Partial thickness Cartilage defect These set of images demonstrate partial thickness cartilage defect – on 3D SPGRE & FSE T2 WI. 3D SPGR 3 dimensional spoiled recalled gradient acquisition FSE T2 WI

Focal Cartilage damage d/to trauma These again show focal cartilage damage following trauma. Marrow edema is an excellent marker for cartilage injury, but is not seen with relatively T1 weighted SPGRE technique. 3D SPGR FSE T2 WI

Cartilage Fissure FSE T2 WI 3D SPGR Sag. FSE T2 WI shows this cartilage fissure outlined by bright synovial fluid. But the underlying cartilage is better seen on SPGRE image. FSE T2 WI 3D SPGR

3D SPGRE image shows this cartilage ‘step-off’ 3D SPGRE image shows this cartilage ‘step-off’. Note FSE T2 WI shows less detail of the cartilage. This is the arthroscopy picture of the same site. 3D SPGR

Subchondral Osteophyte FSE T2 WI 3D SPGR Subchondral osteophyte is a sign of cartilage damage. Subchondral Osteophyte

Delaminating Cartilage injury Sag 3D SPGRE image shows delamination of the trochlear cartilage. Another adjacent slice shows piece of delaminated cartilage in the joint. Delaminating Cartilage injury

Grading of cartilage lesions Outerbridge RE. The aetiology of chondromalacia patellae. J Bone Joint Surg [Br] 1961;43-B:752-7.

Cartilage Lesion Classification

Cartilage Lesion Classification

Cartilage Lesion Classification

Cartilage Lesion Classification

Baeur & Jackson classification Chronic degrading has the worst prognosis

Grading of Chondral lesions

Grading of Chondral lesions

Inter-observer variations in grading Compared 2 trainees with one senior surgeon Rating system used was not discussed Concluded variation in experience was the primary determinant of disagreement. Javed A, Siddique M, Vaghela M, Hui AC. Interobserver variations in intra-articular evaluation during arthroscopy of the knee. J Bone Joint Surg Br. 2002;84:48-49.

Inter-observer variations in grading Classified 19 knees using Outerbridge, Collins & French Society of Arthroscopy scores 4 surgeons Good inter- and intra-rater reliability of ll grading systems Brismar BH, Wredmark T, Movin T, Leandersson J, Svensson O. Observer reliability in the arthroscopic classification of osteoarthritis of the knee. J Bone Joint Surg Br. 2002;84:42-47.

Inter-observer variations in grading 6 cadaver knees underwent arthroscopy and then arthrotomy Outerbridge classification was used Surgeons with more than 5 years in practice had a κ of 0.72 compared to a κ of 0.50 among fellows and surgeons with fewer than 5 years in practice. A κ of 1.00 means perfect agreement and 0.00 means agreement completely by chance. Cameron ML, Briggs KK, Steadman JR. Reproducibility and reliability of the Outerbridge classification for grading chondral lesions of the knee arthroscopically. Am J Sports Med. 2003;31:83-86.

Inter-observer variations in grading Less than 25% variation in the assessment of full thickness cartilage lesions amongst surgeons. Arthroscopy remains the gold standard. Agreement in Arthroscopic and Arthrotomy Assessment of Full-Thickness Articular Cartilage Lesion. Asbjørn Årøen, Cartilage 2013 4: 214

Conclusion Number of classification systems are available. Moderate to good agreement b/w orthopaedic surgeons using any classification. Arthroscopic grading classification can be used for multi-center studies which involve multiple surgeons. Agreement improves with the experience of the orthopeadic surgeon. Arthroscopic evaluation remains the gold standard but newer MRI techniques are catching up.

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