This study reviews outcomes of the first 55 knees implanted with a redesigned metal-backed unicondylar prosthesis at Brigham and Women's Hospital. It reports clinical and radiographic results at an average 5.5-year follow-up and codifies patient selection criteria for unicompartmental knee arthroplasty.
When you are deciding between UKA and TKA in a patient with medial compartment arthritis, the Kozinn-Scott criteria from this paper are the framework you apply: age over 60, weight under 180 lbs, deformity under 15° and correctable to neutral, flexion arc at least 90°, contracture 5° or less, and both cruciates intact.
The final decision cannot be made preoperatively. After arthrotomy, if you find exposed subchondral bone in the opposite compartment or under the patella, you convert to TKA. Small cartilage erosions in non-weight-bearing areas of the opposite compartment are acceptable. Asymptomatic patellofemoral chondromalacia is acceptable. Symptomatic patellofemoral pain is not.
Chondrocalcinosis seen on preoperative films or at arthrotomy should prompt reconsideration — it signals synovial and cartilage pathology beyond one compartment, and this paper reports an ongoing pain case attributable to exactly this finding.
If UKA fails, conversion to TKA is straightforward provided bone-sparing cuts were used at the original operation — a key reason to perform UKA correctly even if you anticipate the patient may eventually need TKA.
This study reviews outcomes of the first 55 knees implanted with a redesigned metal-backed unicondylar prosthesis at Brigham and Women's Hospital. It reports clinical and radiographic results at an average 5.5-year follow-up and codifies patient selection criteria for unicompartmental knee arthroplasty.
When you are deciding between UKA and TKA in a patient with medial compartment arthritis, the Kozinn-Scott criteria from this paper are the framework you apply: age over 60, weight under 180 lbs, deformity under 15° and correctable to neutral, flexion arc at least 90°, contracture 5° or less, and both cruciates intact.
The final decision cannot be made preoperatively. After arthrotomy, if you find exposed subchondral bone in the opposite compartment or under the patella, you convert to TKA. Small cartilage erosions in non-weight-bearing areas of the opposite compartment are acceptable. Asymptomatic patellofemoral chondromalacia is acceptable. Symptomatic patellofemoral pain is not.
Chondrocalcinosis seen on preoperative films or at arthrotomy should prompt reconsideration — it signals synovial and cartilage pathology beyond one compartment, and this paper reports an ongoing pain case attributable to exactly this finding.
If UKA fails, conversion to TKA is straightforward provided bone-sparing cuts were used at the original operation — a key reason to perform UKA correctly even if you anticipate the patient may eventually need TKA.