Purpose <p>Unicondylar knee arthroplasty (UKA) is a less invasive alternative to total knee arthroplasty (TKA) for patients with isolated unicondylar knee osteoarthritis and obtains good functional and clinical results. Still, the revision and survival rates of UKA are inferior compared to TKA. Therefore, patient-specific implants were introduced to obtain more reliable results. This retrospective study compares standard UKA and patient-specific UKA after short-term follow-up.</p> Methods <p>One study group consisted of 50 patients with a standard UKA implant, implanted using navigation technology. The other group consisted of 25 patients with a patient-specific implant, implanted using respective patient-specific instruments.</p> Results <p>2 years postoperatively, functional and clinical scores were similar or better in the standard UKA group. The postoperative range of motion and axial alignment were comparable in both groups. The number of complications was low, without any case of aseptic loosening.</p> Conclusion <p>Standard UKA and patient-specific UKA provide good short-term clinical and functional results. No benefit was obtained using patient-specific implants, which would justify the high cost and effort of this technique for “standard” patients with medial osteoarthritis.</p> Trial registration number <p>NCT03201172 (clinicaltrials.gov).</p>