CHONDROMALACIA PATELLAE

Chondromalacia Patellae

Chondromalacia patellae is softening of articular surface of patella. It can occur due to diverse etiology.
Types
a. Primary idiopathic type
b. Secondary adolescent type
c. An adult type

Primary adolescent chondromalacia Patellae
It is type occurring in adolescent more common in females. The condition occurs without antecedent trauma.
Clinical features
There is dull aching anterior knee pain. Pain is more in flexion (as in going up and down stairs). Cinema Sign: Prolonged sitting with flexed knees produces severe pain, relieved by extension.
Signs
Facet of patella is tender to finger tip palpation. Retro patellar tenderness: Direct patellofemoral compression elicits pain due to rubbing of patella against femur.

Pathology: The condition is graded according damage.
Outebridge’s grading
1) Softening and swelling
2) Fissuring
3) Fibrillation (Crabmeat) appearance
4) Exposure of subchondral bone.

Investigations
X-ray shows patella alta. Tangential view shows lateral tilt or displacement. Degenerative changes or erosion might be seen in facet. The lesion is best visualized by arthroscopy.

Management:
Conservative line with medication ,cast is often used as first line therapy. Immobilization in cast gives adequate rest for revascularization. Quadriceps exercises and hamstring stretching are often prescribed.
Surgery is indicated for chronic pain unresponsive to conservative methods. Surgery aims at correction of malallignment and treatment of diseased cartilage. Lateral ratinacular release is done for malallignment.

For disease cartilage, following procedures are done as per stage
a) Arthroscopic patellar shaving
b) Excision of defects and drilling of subchondral bone
c) Facetectomy
d) Maquet Procedure : This procedure aims at advancing tibial tuberosity to relieve compressive load on joint.


Secondary chondromalacia Patellae
Secondary chondromalacia patellae follows traumatic injury. Trauma can be direct blow, twist or recurrent patellar dislocation. Condition is more common over median ridge. In addition to characteristic pain, buckling and instability in common. There is retro patellar tenderness and lateral patellar tilt. Tangential view X-ray shows detached fragment of bone. Treatment is aimed at treating malallignment. However when degenerate arthritic changes, Patellectomy is treatment of choice.