Background: The joint closure technique used for total knee arthroplasty cases can have an impact on outcomes, especially when considering accelerated rehabilitation programs that follow surgery. In this study, we describe the details of the technical steps involved in performing the water-tight arthrotomy joint closure technique that we developed and use. Methods: A total of 536 patients (average age: 62 years, average body mass index: 34 kg/m2) with primary osteoarthritis of the knee underwent total knee arthroplasty using the modified intervastus approach between 2019 and 2021. We used the water-tight arthrotomy joint closure technique to close the knee arthrotomy incision. Any infections and complications, as well as the duration of surgery and cost related to this wound closure technique, are also reported. Results: Few complications were noted with this closure technique. When we first started using it, there was one case of drainage through the proximal capsular repair which required a return to the operating room 5 days postoperatively for an irrigation and debridement. We also had two cases of superficial skin necrosis along a small part of the incision line which were observed on a weekly basis and which healed uneventfully with application of betadine once daily on the necrotic area. The average time for performing wound closure after total knee arthroplasty was 45 min. Conclusion: We conclude that the water-tight closure approach can achieve very durable, water-tight capsule repairs and results in a decrease in postoperative wound drainage.