- 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:
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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:
Knee arthrodesis following total knee arthroplasty in rheumatoid arthritis.
Knee arthrodesis in the treatment of failed total knee replacement.
