Osteotomy
Osteotomy involves cutting the bone and realining its fragments. This corrects length, alignment and rotation for improved joint mechanics.
- Indications for osteotomy
- Congenital deformity
- Post-traumatic deformity (malunion)
- Common procedures
- Femoral and pelvic osteotomies: for hip dysplasia
- High tibial valgus-producing osteotomies: for isolated medial compartment artitis in knees aligned in varus
Arthrodesis
Arthrodesis involves removing all the articular cartilage of a joint and fusing the bones. This relieves pain while completely restricting the joint range of motion.
- Indications for arthrodesis
- Severe arthritis of the ankle
- Patients with high joint use who are too young for an arthroplasty because there is concern for component wear and the need for early revision
- Salvage for virulent infections in teh elderly
Definition of terms
| Term | Definition |
|---|---|
| Osteotomy | Cutting the bone and realining its fragments. This corrects length, alignment and rotation for improved joint mechanics |
| Arthrodesis (joint fusion) | Remove all articular cartilage and fuse the bones. Relieves pain while completely restricting the joint range of movement |
| Arthroplasty (joint replacement) | Articular cartilage is remodeled, repaired, or replaced |
Arthroplasty
Arthroplasty involves the remodelling, repair, or replacement of articular cartilage. It is also known as replacement arthroplasty or joint replacement. Arthroplasty can be partial or total.
Hip Arthroplasty
Hip replacement arthroplasty is indicated for end-stage arthritis that has failed conservative measures.
Types of hip arthroplasty
| Type | Description |
|---|---|
| Total hip arthroplasty (THA) | Replaces the osteocartilaginous surface of the acetabulam and proximal femur with a bearing surface integrated into the bone. Also indicated for middle-aged adults with femoral neck fracture. The acetabulum is replaced with a metal cup lined with polyethylene and the femur is replaced with a metal stem and ceramic or metal head. |
| Hip hemiarthroplasty | Replaces the diseased osteocartilaginous surface of the proximal femur iwth a bearing surface integrated into bone. Also indicated in elderly adults with femoral neck fractures |
| Hip resurfacing | Replaces a small portion of the femoral head and acetabulum with a smooth metal implant. Rarely used due to high complication rates. |
Knee Arthroplasty
Knee replacement arthropathy is indicated for end-stage arthritis that has failed conservative measures.
Types of knee arthroplasty
| Type | Description |
|---|---|
| Total knee arthroplasty (TKA) | Replaces the disease osteocartilaginous surface of the distal femur, proximal tibia and patella. Often performed without patellar resurfaceing. Distal femur is replaced with a metal prosthetic cap while the proximal tibia is replaced with a metal tray with a polyethylene insert. The patella is replaced with a polyethylene cap |
| Uni-compartmental knee arthroplasty | Replaces the diseased osteocartilaginous surfaces of the medial distal femur and tibia (medial distal compartment) or the lateral distal femur and tibia (lateral compartment) or patellofemoral compartment. |
Complications of Arthroplasty
Complications
| Timing | Complications |
|---|---|
| Intra-operative | Component mal-positioning, vascular injury, nerve injury, fracture |
| Early post-operative | Infection, dislocation, thromboembolic events |
| Late post-operative | Infection, osteolysis or resorption of bone near implant interfaces (worse with malpositioned components), instability |
