CHONDROMALACIACHONDROMALACIA PATELLAEPATELLAE

Literal translation - “Soft Cartilage”

AKAAKA::• Patellofemoral overload syndrome• Patellar Pain syndrome• Anterior knee pain syndrome• Runners Knee

CAUSES:CAUSES:Mechanical overload of the patellofemoral joint.

a) Malcongruence - patellofemoral surfaces

b) Malalignment – extensor mechanism

- weakness of vastus medialis

Single injury – damage to articular surface

PATHOLOGYPATHOLOGYDegeneration of articular cartilage-Precipitant

Changes in articular cartilage + subchondral bone

1.Cartilage N appearance with only biochemical changes but bone shows reactive vascular congestion

OR

2.Cartilage softening/fibrillation with or without subarticular intraosseous hypertension

Fibrillation usually on undersurface of the patella at the jn. of medial and odd patellar facet /median ridge confined to superficial zones and heals spontaneously.

NOT A PRECURSOR OF OA!

Lateral Articular surface involvement-usually congenital tightness of lateral quadriceps expansion

‘Ficat’s hyperpression zone syndrome’

Or

Excessive Lateral Pressure Syndrome

Predisposes to OA

Lateral Release for prophylaxis

CLINICAL FEATURESCLINICAL FEATURES• Introspective teenage girl or athletic young adult• Flat foot / Knock kneed athletes• Spontaneous Pain in front of knee/ beneath the knee

cap• Maybe h/o recurrent displacements/injury• Aggravated by activity/climbing down

stairs/standing after prolonged sitting with knees flexed

• Both knees• Swelling-give way-catching(not true locking)• Grating/grinding sensation when knee is extended

SignsSignsAppears N kneeMalalignment/tilting of patellaQuadriceps wastingEffusionCrepitus on moving the kneeTenderness under the edge of the patellaSmall high patellaIn severe cases a/w Patella Alta“Theatre sign”

Press patella against femur to elicit pain and asking patient to contract the quadriceps first with central pressure then compressing the medial facet and then the lateral facet

Apprehension test + implies previous

subluxation/dislocation.

Patellar tracking with pt seated at edge of the couch, flexing and extending knee against resistance

Patellar alignment gauged by Q angle-angle subtended by the line of quadriceps pull and the line of patellar ligament. Should not exceed 20 degrees

Structures around knee and hip examined r/o referred pain

STAGESSTAGES I:   swelling and softening of the cartilage

II:   fissuring within the softened areas

III: fasciculation of articular cartilage almost to level of subchondral bone;

IV:  destruction of cartilage with subchondral bone exposed

Grading (Bentley 1992)Grading (Bentley 1992)

• Grade I: area <0.5 cm diameter

• Grade II: Area 0.5 – 1.0 cm diameter • Grade III: area 1.0 – 2.0 cm diameter

• Grade IV: area >2 cm diameter

a: softening, swelling/fibrillation of cartilage b: Full thickness cartilage loss to bone

IMAGINGIMAGING• X Rays- skyline view

lateral view with knee half flexed

Tangential views at 30, 60 and 90 degrees of

flexion

Best seen on slightly overexposed lateral X ray

Axillary radiograph determines which facet is involved

Most accurate to measure malpositon CT/MRI with knee in full extension and varying degrees of flexion.

• Diagnosis made only on Arthroscopy or surgery

• Arthroscopy is useful to r/o other causes of anterior knee pain. Also to know presence and extent of the lesion and probing of patella with soft probe

• Gauge patellofemoral congruence, tracking and alignment

DIFFERENTIAL DIAGNOSISDIFFERENTIAL DIAGNOSIS• Patellofemoral overload- maltracking

overuse• Patellar instability-subluxation/tilt• Intraarticular pathology-plica syndrome

meniscal disorders

Osteochondriotis dissecans

Patellofemoral arthritis

Peripatellar disorders-bursitis/tendinitis/apophysitis

Bipartite patella bone tumours

Hip disorders- slipped capital femoral epiphysis

TREATMENTTREATMENT

• Conservative

• Operative

•

Conservative RxConservative Rx• Reassurance• Ice Application• Physiotherapy• Avoid stressful activities• Stretching and strengthening medial quadriceps

15 mins 4 times/day – Quad sets (bicycling, pool running, swimming flutter kick)

• Aspirin / Ibuprofen / Naproxen• Support for a valgus foot STEROIDS BEST AVOIDED

Knee brace

Operative RxOperative Rx Indications:

1. Abnormality correctable by operation

2. Conservative Rx tried for at least 6 months

3. Pt genuinely incapacitated

Surgical OptionsSurgical Options1. Lateral Release

2. Proximal Realignment

3. Distal Realignment

4. Distal elevation of Patellar ligament

5. Chondroplasty

6. Patellectomy

Preventive MeasuresPreventive Measures

Short-arc extensions Done sitting up or lying down. Rolled-up towel to support the thigh keep leg and foot in the air for 5 seconds.Lower foot as knee is bent slowly. Repeat 10 times for each leg, twice a day.

Straight-leg raises Done lying down.

Lift whole lower limb at the hip with the knee extended

keep it up in the air for 5 seconds. Then lower slowly.

Repeat 10 times for each leg, twice a day.

Quadriceps isometric exercises Done sitting up, with legs extended in front Tighten quadriceps muscles by pushing the knees down onto the floor. Hold for 5 seconds. Repeat 10 times each leg, twice a day.

Stationary bicycling low tension setting improves exercise

tolerance without stressing the knee.

Seat should be high enough so that the leg is straight on the down stroke.

Start with 15 minutes a day and work up to 30 minutes a day.

THANK YOUTHANK YOU