Methods Total of 23 patients with combined osteoarthritis knee and proximal tibial stress fracture were enrolled in this study. Of those 23 patients, 18 were females and five were males. All patients were managed surgically by TKA (PCL sacrificing) with a long tibial stem (straight or with offset). Assessments of union and tibiofemoral alignment were carried out using radiographs. Clinically, patients were evaluated by assessment of knee range of motion, knee society score (KSS), and knee injury and OA outcome score. Results The average follow-up period was 6.5 ± 2.3 years (range from 5 to 9 years) all fractures united in 3– 8 months (average 3.2 months), and mean range of motion improved from 89°±8° to 119°±6°, mean knee society score improved from 32 ± 8 to 87 ± 5, mean knee injury osteoarthritis outcome score improved from 27 ± 6 preoperatively to 79 ± 5 after a minimum of 5 years follow-up. no complications (instability, infection, or patella mal-tracking) were reported, although 1 case had a femoral intraoperative condyle fracture which was fixed by screws with no effect on the outcome. Conclusion The use of a long tibial stem TKA is an effective and reproducible single surgical procedure in the management of combined osteoarthritis knee and proximal tibial stress fracture. Satisfactory clinical scores and radiological outcomes were achieved and proper limb alignment was restored obviating the need for further fixation or grafting.