Knee - Osteotomies

Valgus osteotomy most commonly performed (varus knee) and is indicated in patients that have uni compartmental disease, are less than 60 - 70 years old, are of optimal weight, have an active occupation or lifestyle which they want to maintain and have a good range of motion

NB: ROM is not likely to improve with an osteotomy

INDICATIONS

1. Age:  physiologic age < 60 yrs in an athlete, laborer, or anyone who needs to knee down such as for gardening (TKR will generally not allow the patient to kneel)
2. Weight: > 80 kg are at increased risk for component failure;
3. Angular Deformity: 
   1. > 15 deg of fixed varus deformity (often patients will have varus laxity)
   2. < 15 degrees flexion contracture 
   3. > 90 degrees flexion
4. Radiologically intact lateral (or medial) and patellofemoral compartments

CONTRAINDICATIONS:

1. Tibial Subluxation > 1 cm 
2. RA &  inflammatory arthritis 
3. ACL tear 
4. osteochondral injuries with involvement of more than 1/3 the condylar surface or OCD lesion of more than 5 mm deep 

CLINICAL

• Observe patient walk (look for varus thrust) 
• Stability
• Q Angle
• Compensatory arc of motion  - to correct a valgus knee deformity - for a 20-degree varus osteotomy, 20 deg of abduction at the hip is required so pt does not end up with an adduction deformity
• Examine the foot and ankle to rule out fixed varus deformities which may worsen medial compartment loading
• Leg length discrepancy Coventry closing wedge osteotomy might be indicated, where as, if the arthritic side is shorter (than the other leg), then consider opening wedge osteotomy