Background: minimally invasive total knee arthroplasty (MIS-TKA) has been gradually promoted in clinical practice, but its effect is still controversial. Bone metabolism index can reflect the situation of bone repair and injury after operation clearly, and it is suitable to evaluate the effect of this kind of operation. Objective: To investigate the effect of minimally invasive and traditional total knee arthroplasty (TKA) on the early postoperative bone metabolism in patients with knee osteoarthritis (KOA), and to evaluate the clinical effect. Methods: 90 patients with koa who underwent unilateral TKA from January 2019 to December 2019 were randomly divided into two groups: 45 patients with traditional TKA and 45 patients with MIS-TKA. The bleeding volume, operation time, start time of straight leg raising training, incision length and 24 hours after operation were compared between the two groups The visual analogue score (VAS score) of pain within hours; the serum ALP and bmd-akj monitoring indexes before and 1 month after operation; and the specific sequence of carboxy terminal peptide β (β-CTX), amino terminal pro peptide (P1NP), tartrate resistant acid phosphate of type I collagen on the 3rd, 5th, 7th, 15th and 30th day before and after operation The trend of changes of TRACP5b and BGP and the occurrence of complications. Results: The incision length, the start time of straight leg elevation training and the VAS score within 24 hours after operation in the minimally invasive group were all better than those in the traditional group, the difference was statistically significant (P < 0.001). The operation time in the minimally invasive group was longer than that in the traditional group, the difference was statistically significant (P < 0.001), but there was no statistically significant difference in the amount of bleeding between the two groups (P > 0.001). There was no significant difference in ALP and bmd-akj between the two groups (P > 0.05); there was no significant difference in β-CTX, P1NP, TRACP5b and BGP between the two groups before operation (P > 0.05); the levels of β-CTX, P1NP, TRACP5b and BGP in the minimally invasive group after operation were significantly lower than those in the traditional group (P < 0.05); there was no infection, lower extremity deep vein thrombosis and other complications in the two groups after operation.