Partial vs. Total Knee Replacement Surgery
The knee has three compartments-the medial compartment (inside aspect of the knee), the lateral compartment (outside of the knee) and the patellofemoral compartment (in front of the knee). In some knee osteoarthritis patients, only one compartment of the knee is affected-usually the medial compartment. A partial or unicondylar knee replacement, as its name suggests, replaces only the affected compartment of the knee. On the other hand, a total knee replacement involves the replacement of all three compartments of the knee.
Source: Verywell Health