OSTEOARTHRITIS

Osteoarthritis : 

Osteoarthritis Shahbaz Shafi Malik BSc (Hons), MB BCh, MRCS Norfolk & Norwich University Hospital

OA : 

OA Chronic disorder Degenerative joint disease Result in progressive erosion of articular cartilage

Epidemiology : 

Epidemiology Starts at 50 years of age Female > male (2: 1) 10% of general population

Classification : 

Classification Primary OA Idiopathic and appears insidiously arises without obvious predisposing influences Oligo-articular Age Genetic – familial tendency Obesity – OA knee

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Secondary OA – presence of other predisposing factor Previous trauma Intrarticular fracture, recurrentl dislocation Infection Septic arthritis Congenital deformity of a joint Perthe’s diease, SUFE Inflammatory RA Underlying systemic diseases DM, Haemochromatosis, Obesity

Pathology : 

Pathology The cardinal features are: Progressive loss of cartilage thickness Subarticular cyst formation and sclerosis Remodelling of the bone ends and osteophyte formation Synovial irritation Capsular fibrosis

Pathogenesis : 

Pathogenesis The normal homeostasis in the joint is disturbed OA is a disease of wear-and-tear : Occurs in old age Weight bearing joints Increase frequency in the joints predisposed to abnormal mechanical stress  obese & previous joint deformity Genetic factors Risk increased with: Reduced Bone density High levels of oestrogen

Pathogenesis : 

Pathogenesis

Pathogenesis : 

Pathogenesis Characterized by significant changes of: Composition Mechanical properties of cartilage Early  the degenerating cartilage Increased in water Decreased concentration of proteoglycans Weakening of collagen network (reduce type II collagen) IL-1, TNF and NO are increased in the joint Increased apoptosis of chondrocytes These result in: Reduce tensile strength Reduce resilience  Degeneration

Morphology : 

Morphology Early stage: Increased in chondrocytes Subsequently  cracking of the matrix Gross Granular surface Small fractures & dislodge, producing ‘joint mice’ Osteophytes formation

Clinical features : 

Clinical features Pain Stiffness Swelling Deformities Joint instability Loss of function

History : 

History Age - > 50 years BMI Occupation – what type? Any history of trauma around the joint? Secondary causes – congenital, RA Any joint pain become worst by activity, relieved by rest. Joint stiffness – early morning, long rest Swelling? Affect on daily activity !! Climbing stairs

Examination : 

Examination General examination Inspection Gait (antalgic!) Deformity (varus/valgus) Muscle wasting (quadricep) Joint swelling erythema Palpation Joint effusion Tenderness Palpable osteophytes

Examination : 

Examination Movement Crepitus Reduced/limited ROM Sepcial test Valgus/varus stress

Investigation: X-ray features : 

Investigation: X-ray features Narrowing or loss of joint space 1st sign of OA - reflects loss of articular cartilage; main pathology Osteophyte formation-around the periphery of the joint. Subchondral sclerosis-looks very white on the radiograph. Subchondral cyst

X-ray features : 

X-ray features

Management - Conservative : 

Management - Conservative Pain relief Analgesic and NSAIDS Intra-articular corticosteroid To increase movement to prevent muscle wasting and deformity/contracture. physiotherapy/exercise programme, non -weight bearing exercise to strengthen muscle strength (cycling, swimming etc). To reduce load on the joint Weight loss if patient is obese Use of walking stick to distribute the load Avoid unnecessary stress,eg jogging,climbing stairs

Operative management : 

Operative management Arthroscopic debridement and cleaning of the joint cavity and infusion of synthetic synovial fluid. Arthrodesis If stiffness is acceptable and neighbouring joints are not likely to be prejudiced. Usually done in young patient. Arthroplasty Joint replacement -usually done in old patient.

OA - Knee : 

OA - Knee Knee is a complex synovial joint formed between femoral condyles, tibial condyles & patella. Stabilised by variety of ligaments. Active movement at the knee are: Flexion/extension, medial rotation & lateral rotation.

Articular Cartilage : 

Articular Cartilage Reduce friction at the joint Act as a cushion to absorb the shock associated with joint use Transmit weight loads to the underlying bone.

Mechanical Axis : 

Mechanical Axis The mechanical axis of the knee is a line extending from the center of the hip joint  to the middle of the ankle joint. This line is practically perpendicular to the ground. In a healthy, well aligned knee joint, the mechanical axis  passes through the middle of the knee. Only when the mechanical axis passes through the center of the knee joint, the stresses on the knee joint surfaces are uniform in all areas of the joint and well balanced. In many knee joint diseases, the mechanical axis is disturbed and does not pass through the center of the joint. This disturbance results in the overload of distinct areas of the knee joint leading to their damage. The patella lies not symmetrically in its groove.

Mechanical Axis : 

Mechanical Axis

Radiological exam : 

Radiological exam Views Standing AP (weight bearing)/Lateral Notch patellar views (Sunrise view) Posteroanterior intracondylar (PAIC) Tangential patellar Findings Joint space narrowing Medial tibiofemoral joint space narrowing Patellofemoral joint space narrowing Lateral joint space narrowing to lesser extent New subchondral bone formation Tibia lateral subluxation Osteophyte formation Medial osteophytes are most prominent initially

Grading : 

Grading The best way to see if osteoarthritis is present and see the severity is by looking at x-rays of the knee. OA is classified into 5 stages : Grade 0:     · Normal knee joint     · No loss of cartilage and no deformation Grade 1:     · Some loss of articular cartilage     · If severe loss of cartilage, joint space narrows     · Osteophytes may be seen

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Grade 2:     · More activity in the bone under the cartilage     · Increased activity can lead to bone hardening (sclerosis) and cysts     · Change in bone density (whitening of bone on x-ray) Grade 3:     · Some deformations on edge of bone     · Rough edges     · Increased joint narrowing Grade 4:     · Complete loss of joint space     · Definite deformity of bone ends     · Changes in joint shape mean the bone contour has been altered

Role of diacerein & glucosamine : 

Role of diacerein & glucosamine Diacerein is IL-1 inhibitor Disease modifying effect on O.A. Prophylactic use of diacerein leads to lower degree of articular stiffness when compared to glucosamine Prophylactic chondroprotective effects of diacerein and glucosamine are histologicaly similar.

Surgery : 

Surgery Arthroscopic debridement Proximal tibial osteotomy Distal femoral osteotomy Chondral resurfacing procedure Autologous chondrocyte grafting Mosaicplasty TKR Arthrodesis Patellectomy UKA

Arthoscopic techniques : 

Arthoscopic techniques Simple lavage Debridement Abrasion chondroplasty

OSTEOCHONDRAL & AUTOLOGOUS CHONDROCYTE TRANSPLANTATON : 

OSTEOCHONDRAL & AUTOLOGOUS CHONDROCYTE TRANSPLANTATON Healthy chondrocytes are harvested from an uninvolved area of injured knee. Grown in tissue culture Injected into knee cartilage defect. Sealed over with a periosteal flap from proximal medial tibia Still experimental

Arthoplasty : 

Arthoplasty Preservation of bone stalk Immedite wt. bearing Shorter recovery time Easier revision to TKR Disadvantages Technical difficulty Prosthesis loosening & failure

TKR : 

TKR

References : 

References 1.