Osteoarthritis (OA)

Contents

Definition

noninflammatory disorder of movable joints characterized by deterioration of articular cartilage and formation of new bone at the joint surfaces and margins
a.k.a. “Degenerative Joint Disease”

OA XR Findings
1) Joint space narrowing
2) Subchondral sclerosis
3) Subchondral cysts
4) Osteophytes

Clinical Features

cardinal symptom is pain with joint use that is relieved by joint rest; nocturnal pain occurs in late stages
range of motion limitations, especially flexion and extension
crepitation with joint motion, signifies bone-on-bone quality of degenerative arthritis

Radiographic Abnormalities	Pathologic Feature
Loss of joint space	Cartilage erosion
Subchondral sclerosis	Complete loss of cartilage and eburnation of bone
Subchondral cysts	Infiltration of degenerative microfractures by synovial fluid
Osteophytes	Synovial membrane stimulation, revascularization of remaining cartilage and capsular traction
Loose Bodies	Fragmentation of osteochondral surface
Bony collapse	Compression of weakened bone

Osetoarthritis of the Knee

Clinical Features

pain is localized to the affected compartment (medial > lateral > patellofemoral)
joint line tenderness ± joint effusion
patients generally lack full range of motion:

-flexion contractures ? posterior osteophytes and capsular contracture restrict
angular deformities:

-varus: collapse of medial compartment, bowlegged appearance

-valgus: collapse of the lateral compartment, knock-kneed appearance

Management

Conservative	NSAIDs / COX-2 inhibitors (celecoxib), chondroitin Orthoses, such as elastic knee supports, or valgus unloading braces Intraarticular corticosteroid injections Viscosupplementation with hyaluronan derivatives Ambulatory aids, such as a cane, crutches, or walker
Invasive	Arthroscopic debridement Osteotomy High tibial osteotomy (HTO) for tx. of varus deformity Distal femoral osteotomy for tx. of valgus deformity Unicompartmental knee arthroplasty Patellofemoral arthroplasty Total knee arthroplasty (TKA)

Osteoarthritis of the Hip

Clinical Features

pain (groin, medial thigh) and stiffness aggravated by activity

-obturator nerve becomes irritated by the arthritic joint causing the pain
decreased ROM (internal rotation is lost first), crepitus
± fixed flexion contracture leading to apparent limb shortening (Thomas test)

Management

Conservative	Weight reduction, activity modification, physiotherapy NSAIDs / COX-2 inhibitors (celecoxib) Ambulatory aids, such as a cane, crutches, or walker (cane is held in hand opposite the involved hip)
Invasive	Arthroscopic debridement Femoral or pelvic osteotomies (rare) Arthrodesis (fusion) Total hip arthroplasty (THA)