Background: Considering the increasing number of young and active patients needing TKA, orthopedic surgeons are looking for a long-lasting and physiological bond for the prosthetic implant. Multiple advantages have been associated with cementless fixation including higher preservation of the native bone stock, avoidance of cement debris with subsequent potential third-body wear, and the achievement of a natural bond and osseointegration between the implant and the bone that will provide a durable and stable fixation. Discussion: Innovations in technology and design have helped modern cementless TKA implants to improve dramatically. Better coefficient of friction and reduced Young’s modulus mismatch between the implant and host bone have been related to the use of porous metal surfaces. Moreover, biologically active coatings have been used on modern implants such as periapatite and hydroxyapatite. These factors have increased the potential for ingrowth by reducing micromotion and increasing osteoconductive properties. New materials with better biocompatibility, porosity, and roughness have been introduced to increase implant stability. Conclusions: Innovations in technology and design have helped modern cementless TKA implants improve primary stability in both the femur and tibia. This means that short-term follow-up are comparable to cemented. These positive prognostic factors may lead to a future in which cementless fixation may be considered the gold-standard technique in young and active patients.

Case: A 51-year-old woman, affected by end-stage renal disease, presented with 16-month-old ruptures of the right patellar tendon and the left quadriceps tendon. Since she had been nonambulatory for more than a year, the authors decided to perform a bilateral one-staged reconstruction with an Achilles tendon allograft on the right side and a full extensor mechanism allograft on the left side, achieving excellent clinical and functional results at 57 months’ follow-up. Conclusions: Bilateral spontaneous rupture of the extensor mechanism of the knee is a rare but dramatic occurrence. Allograft can be considered as a treatment option in case of chronic lesion or delayed reconstruction, with satisfactory midterm outcomes.