Single-surgeon prospective cohort reporting ten-year survival of 144 Oxford medial unicompartmental knee arthroplasties. All patients had anteromedial osteoarthritis with strictly verified intact ACLs. The central question: can a fully congruous mobile bearing match TKA survival while eliminating the polyethylene wear failures that plagued earlier UKA designs?
UKA had a reputation for high failure rates before this paper, largely because incongruous fixed-bearing designs generated contact pressures that destroyed thin polyethylene inserts within a few years.
This study established the conditions under which UKA can match TKA survival: congruous mobile bearings + strict patient selection (anteromedial OA pattern, intact ACL, correctable varus on stress radiograph).
When you see a patient with isolated medial compartment OA and a synovially covered ACL confirmed at arthroscopy or MRI, this paper is the evidence base for offering UKA rather than defaulting to TKA.
The ACL rule is the most testable clinical pearl: an absent or damaged ACL is a hard contraindication because it generates shear at the tibial interface and causes loosening at ten times the rate of ACL-intact knees. Patellofemoral disease and chondrocalcinosis are NOT contraindications — a common misconception worth knowing for boards and for counseling patients pre-operatively.
Single-surgeon prospective cohort reporting ten-year survival of 144 Oxford medial unicompartmental knee arthroplasties. All patients had anteromedial osteoarthritis with strictly verified intact ACLs. The central question: can a fully congruous mobile bearing match TKA survival while eliminating the polyethylene wear failures that plagued earlier UKA designs?
UKA had a reputation for high failure rates before this paper, largely because incongruous fixed-bearing designs generated contact pressures that destroyed thin polyethylene inserts within a few years.
This study established the conditions under which UKA can match TKA survival: congruous mobile bearings + strict patient selection (anteromedial OA pattern, intact ACL, correctable varus on stress radiograph).
When you see a patient with isolated medial compartment OA and a synovially covered ACL confirmed at arthroscopy or MRI, this paper is the evidence base for offering UKA rather than defaulting to TKA.
The ACL rule is the most testable clinical pearl: an absent or damaged ACL is a hard contraindication because it generates shear at the tibial interface and causes loosening at ten times the rate of ACL-intact knees. Patellofemoral disease and chondrocalcinosis are NOT contraindications — a common misconception worth knowing for boards and for counseling patients pre-operatively.