The knee is divided into three compartments, the medial compartment, the lateral compartment, and the patellofemoral compartment. Degenerative arthritis of the knee can affect any of these compartments, and 1/3 of patients with knee osteoarthritis have early lesions limited to one compartment. Current surgical options for unicompartmental arthritis include unicompartmental knee arthroplasty (UKA), high tibial osteotomy (HTO), and total knee arthroplasty (TKA). High tibial osteotomy is mainly used in younger, more active and obese patients, and as a transitional procedure to total knee arthroplasty, it has the disadvantage of incomplete symptomatic relief and short maintenance, and is less frequently used in older age groups. Unicondylar arthroplasty, on the other hand, is gaining more and more attention due to the prosthesis design, case selection, and improved surgical techniques. Our department has been performing unicondylar arthroplasty since 2003. The results of UKA surgery are now encouraging, with Berge 2005 reporting a 13-year survival rate of 98% for the Miller-Galante prosthesis and Cartier 2007 reporting a 10-year survival rate of 94.5% for the 161-knee UKA. Our department has been performing this technique since 2003, with good early to mid-term results. The classic indication for unicondylar arthroplasty is for patients with low activity, no significant obesity, and over 60 years of age. The impact of patello-femoral joint degeneration is more controversial. In our clinical work it is difficult to find patients with purely normal patellofemoral joints, and our data show that even if patellofemoral degeneration is present (Alhback stage 0-I), the absence of a history of persistent anterior knee pain is not a contraindication to UKA. In our case follow-up, progression of patello-femoral degeneration was also observed, and its long-term regression remains to be seen. The effect of weight on the postoperative outcome of unicondylar arthroplasty is also controversial; the classical indications for UKA exclude obese patients, but there is no rigorous evidence-based data to suggest that modern artificial knee unicondylar arthroplasty is only indicated for patients of appropriate weight. The data from this group show little effect of overweight (BMI 25-32) in the near to mid-term. This may be related to the design of the prosthesis, the placement of the appropriate prosthesis size, the balance of the flexion and extension gaps, and the balance of the internal and external compartments (preventing the placement of too thick/thin prostheses). Of course, no study comparing severely overweight and extremely overweight patients was done in this group. Although it has been reported in the literature that UKA has an advantage over TKA in terms of improved joint mobility, our results show little difference between the two in terms of improved joint mobility.Ackroyd et al. compared the 10-year follow-up results of 408 cases of UKA and 531 cases of TKA, with an excellent rate of 77.9% for UKA; and only 75.1% for TKA;; 93.8% for flexion above 90 degrees after UKA, while only 83.7%; TKA could be flexed above 90 degrees after surgery. The better results in our group may be related to the selection of patients who are all simple osteoarthritis patients. ukA is associated with less surgical blood loss, faster recovery, the ability to move off the floor early, shorter hospital stay, better postoperative function, and lower hospital costs compared to TKA. Our results validate this point. In addition, it has been found that UKA is superior to TKA in terms of improving proprioception, especially in joint mobility. This is apparently associated with the preservation of more autologous tissue.UKA has similar early and mid-term complication rates compared with TKA, and is similar in terms of improved function (postoperative joint mobility, pain relief), but with less injury, faster recovery, and lower cost, making it a worthwhile surgical option to consider for the treatment of unicompartmental arthritis.