- See: Arthrodesis Menu: / PreOp Planning
- Discussion:
- arthrodesis remains a treatment option for patients who have recurrent infection, or who are poor candidates for reimplantation;
- problems inherent in the performance of knee arthrodesis following a total knee arthroplasty complicated by infection are bone loss,
shortening, gait disturbance, & inability to eradicate infection;
- fusion rates of revised knee arthroplasties are all significantly lower than primary knee arthrodesis rates.
- total knee arthroplasty of the unconstrained or semiconstrained types in multiple series were easier to fuse than constrained total knees;
- reduction in bone stock as caused by infection further decreases fusion rate;
- type of prosthesis affects success of fusion:
- w/ unconstrained prosthesis:
- time to union is 2.5 months;
- success rate ranges from 70-80 %
- w/ hinged implant:
- time to union is 22 months;
- success rate is about 55%;
- bone grafting will increase chance of union;
- attempted fusion in the face of chronic infection will decrease success rate to below 20%;
- Indications for Fusion:
- failed total knee arthroplasty w/ high functional demand;
- single-joint disease;
- deficient extensor mechanism;
- poor soft-tissue coverage that cannot be adequately reconstructed;
- immunocompromised patient, & highly virulent microorganism;
- Specific Techniques:
- external fixator:
- success rate of 70%- 80%;
- complications: peroneal nerve palsy and pin tract infections.
- IM nailing:
- fusion rates of 80% to 85% are reported.
- procedure is lengthy & technically demanding, & may have high blood loss;
- if there has been extensive joint line resections (from previous surgeries) consider intercalary allograft;
- patients are quickly ambulatory on the treated extremity;
- successful fusion usually occurs within four to six months.
- plating
Arthrodesis of the knee after failed infected total knee arthroplasty.
Advanced concepts in knee arthrodesis.
Knee arthrodesis following total knee arthroplasty in rheumatoid arthritis.
Knee arthrodesis in the treatment of failed total knee replacement.