This nationwide Danish registry study characterized the incidence, indications, techniques, and outcomes of knee arthrodesis after failed total knee arthroplasty. It drew on 92,785 primary TKAs performed over 17 years to identify 164 arthrodesis cases. The study provides the largest population-level dataset on this salvage procedure.
When a TKA is so compromised that arthrodesis is being considered, the patient is rarely dealing with a single problem. Nearly half of patients in this series had two or more simultaneous indications, most commonly infection layered on top of extensor mechanism disruption or soft tissue deficiency.
Infection is the dominant driver (93% of cases), so your primary goal before arthrodesis is infection control — but eradication is achieved in only 74%, even after arthrodesis.
Fixation choice matters: intramedullary nailing achieved fusion in 84% vs 61% with external fixation (p=0.01). When bone stock allows, IMN is the preferred construct. The more revision surgeries a patient has had beforehand, the lower the fusion rate — bone stock loss accumulates with each attempt.
Set realistic expectations with patients: solid fusion is achieved in only 65%, one in five will need repeat arthrodesis, and one in seven will ultimately lose the limb to above-knee amputation. Arthrodesis is a salvage — not a solution.
This nationwide Danish registry study characterized the incidence, indications, techniques, and outcomes of knee arthrodesis after failed total knee arthroplasty. It drew on 92,785 primary TKAs performed over 17 years to identify 164 arthrodesis cases. The study provides the largest population-level dataset on this salvage procedure.
When a TKA is so compromised that arthrodesis is being considered, the patient is rarely dealing with a single problem. Nearly half of patients in this series had two or more simultaneous indications, most commonly infection layered on top of extensor mechanism disruption or soft tissue deficiency.
Infection is the dominant driver (93% of cases), so your primary goal before arthrodesis is infection control — but eradication is achieved in only 74%, even after arthrodesis.
Fixation choice matters: intramedullary nailing achieved fusion in 84% vs 61% with external fixation (p=0.01). When bone stock allows, IMN is the preferred construct. The more revision surgeries a patient has had beforehand, the lower the fusion rate — bone stock loss accumulates with each attempt.
Set realistic expectations with patients: solid fusion is achieved in only 65%, one in five will need repeat arthrodesis, and one in seven will ultimately lose the limb to above-knee amputation. Arthrodesis is a salvage — not a solution.