Compared with primary total knee arthroplasty, revision unicompartmental knee arthroplasty was correlated with poorer outcomes; however, researchers theorized this may have been a result of poorer preoperative function.
The researchers reviewed a prospective database of patient-reported outcomes for all medial unicompartmental knee arthroplasty (UKA) procedures performed at a single center between August 2006 and October 2011. Using Oxford Knee, EuroQol-5D (EQ5D) and health VAS scores, the researchers compared outcomes for 518 patients (546 knees) who underwent UKA with 6,753 patients who underwent primary total knee arthroplasty (TKA). The researchers also used perioperative imaging and clinical notes to identify patients who were indicated for revision or in need of bone grafting, stems and augments. Mean follow-up of patients was 20 months.
Results showed out of the 546 medial UKAs performed, 29 patients needed revision UKA at a mean of 25 months. The rate of revision for primary TKA was significantly lower at 0.8% at a mean of 19 months, according to the researchers. Among the 29 patients needing revision UKA, 25 patients were revised to TKA.
According to the researchers, none of the patients who needed medial UKA revision underwent simultaneous bilateral surgery. Reasons for revision included aseptic loosening, osteoarthritis progression, persistent pain, infection, polydislocation and periprosthetic fracture. Ten patients needed augments, stemmed implants or bone grafts.
No significant differences were observed in preoperative Oxford knee, EQ5D or health VAS scores between patients with successful UKA and patients needing revision surgery, according to the researchers. However, Oxford knee and EQ5D scores became poorer before revision surgery.
Preoperative and postoperative health VAS scores were not significantly different between patients who needed revision surgery and those who underwent successful UKA or primary TKA.
Compared with patients who underwent revision surgery, patients who had a successful UKA had greater improvements in Oxford knee scores, according to researchers. ‒ by Monica Jaramillo
Disclosures: The researchers report no relevant financial disclosures.