- Age:
- physiologic age < 60 yrs in an athlete, laborer, or anyone who needs to knee down such as
for gardening (remember that a
TKR will generally not allow the patient to kneel);
- Angular Deformity:
- less than 15 deg of fixed varus deformity (often patients will have varus laxity);
- no more than 15 degrees flexion contracture
-
valgus deformities:
- valgus of upto 12 deg can be corrected by tibial osteotomy;
- in active pt w/ isolated
lateral compartment OA & valgus knee, either
HTO or
distal femoral osteotomy can relieve symptoms.
- for valgus deformities > 12 deg, distal femoral osteotomy is preferred in order to maintain joint line parallel to floor.
- distal femoral osteotomy avoids excessive joint line obliquity.
- Flexion:
- less than 90 degrees flexion is a contraindication to HTO;
- Tibial Subluxation / Varus Thrust:
- lateral tibial subluxation more than 1 cm is a contraindication
- instability in full extension makes it difficult to obtain correct position by tibial
osteotomy, and in these cases joint replacement is required;
- note that a large varus thrust can still place a knee into a relative varus
during ambulation (eventhough w/ operative correction into valgus);
- Abduction:
- when performing either a varus or valgus osteotomy, compensatory arc of motion must be present before surgery.
- for a 20-degree varus osteotomy, 20 deg of abduction is required so pt does not end up with an adduction deformity.
- Other Conditions:
- contraindicated w/
RA, inflammatory arthritis,
chondrocalcinosis;
- preop pain in knee w/ pt is at rest should be minimum, since pain at rest may indicate that there is an inflammatory component to dz;
- ACL tear is a relative contra-indication;
- osteochondral injuries:
- w/ involvement of more than 1/3 the condylar surface or OCD lesion of more than 5 mm deep, osteotomy alone
may not be sufficient to restore adequate function to the knee (in these cases consider allografting);
- Tenderness:
- valgus osteotomy of prox tibia is indicated w/ medial tenderness only;
- pain should be relieved by rest;
- Arthroscopic Findings:
- Radiographs for HTO:
- Weight:
- pts who weigh
80 kg are at increased risk for component failure;
