Knee Flashcards
Indications for High Tibial Osteotomy
- young, active patient (<50 years) in whom an arthroplasty would fail due to excessive wear
- healthy patient with good vascular status
non-obese patients - pain and disability interfering with daily life
- only one knee compartment is affected
- compliant patient that will be able to follow postop protocol
Contraindications for High Tibial Osteotomy
- inflammatory arthritis
- obese patient BMI>35
- flexion contracture >15 degrees
- knee flexion <90 degrees
- procedure will need >20 degrees of correction
- patellofemoral arthritis
- ligament instability
- varus thrust during gait
Contraindications for Varus-producing High Tibial Osteotomy
In addition to generic contraindications for HTO
- Medial compartment OA
- Loss of medial meniscus
- Femoral condyle hypoplasia (DFO is better)
Contraindications for Valgus-producing High Tibial Osteotomy
In addition to generic contraindications for HTO
- Lateral compartment cartilage thinning
- Loss of lateral meniscus
- Lateral tibial subluxation >1cm
- Medial compartment bone loss >2 mm
- Varus deformity >10 degrees
Indications for Unicompartmental Knee Replacement
- Unicompartmental arthritis
- Age > 60
- Weight < 82kg
- Low demand
Contraindications for Unicompartmental Knee Replacement
- Inflammatory arthritis
- ACL deficiency (absolute contraindication for mobile bearing and lateral UKR)
- Fixed varus > 10 degrees
- Fixed valgus > 5 degrees
- Flexion contracture > 10 degrees
- Knee ROM less than 90 degrees
- Meniscectomy of other compartment
- High-demand patients
- Arthritis in any other compartment
Indications for Knee Arthrodesis
- Painful ankylosis after infection or trauma
- Neuropathic arthropathy
- Tumor resection
- Salvage for failed TKR
- Loss of extensor mechanism
Goals / Steps in Revision TKR
- Infection rule out
- Extract component with minimal bone loss
- Bone defects restoration
- Joint line restoration
- Ligament balance
- Stable implants
- Soft tissue coverage
Steps in Medial release in TKR
- Deep MCL to mid-coronal plane of tibia
- Osteophyte removal
- Posteromedial corner release
- Subperiosteal sleeve MCL release
- Medial Tibial reduction osteotomy
- PCL release (change to PS knee)
- Semimembranosis release (especially with FFD)
- Pie-crust MCL
- Complete MCL release (change to varus/valgus constrained unhinged knee)
Steps in Lateral release in TKR
- Osteophytes
- Posterolateral capsule
- Iliotibial band pie-crust or off Gerdy’s (if tight in extension)
- Popliteus (if tight in flexion)
- LCL (change to constrained TKR, especially if popliteus released)
Caton Deschamps ratio
Height of patella articular surface = A
Distance from distal edge of patella articular surface to the anterior tibial joint line = B
Caton Deschamps = A / B
Knee has to be at 20 to 80 degrees (as per original paper)
0.6 to 1.3 is normal
