The primary study objective is to evaluate a cementless partial knee system that has a modular 3-D printed porous metal tibial component and a cemented partial knee system. The hypothesis is that at minimum 2-year follow-up, fixed bearing medial partial knee replacements using cementless and cemented fixation will demonstrate no differences in clinical outcome.

This is a prospective, randomized, unblinded clinical trial of 100 patients will be enrolled by invitation of the principal investigator. Inclusion criteria include patients 18-85 years old, patients receiving a medial fixed bearing partial knee replacement and patients deemed suitable for both cemented and cementless fixation after review of the preoperative radiographs. Minimum two-year outcome will be analyzed, and long-term follow-up will continue to 5 years.

Inclusion Criteria:

• Age18-85 years old
• medial fixed bearing partial knee replacement
• bone suitable for both cemented and cementless fixation after review of the preoperative radiographs.

Exclusion Criteria:

• Non-English speakers
• current smokers
• grossly porotic bone
• advanced other compartment arthritis at the time of surgery necessitating a total knee arthroplasty (TKA)
• previous high tibial osteotomy with prior hardware
• patients who are randomized but are deemed unsuitable to receive the assigned implant by the surgeon due to bone quality or bone cuts