The surgical treatment of a secondary gonarthrosis caused by haemophilic arthropathy needs high quality in soft tissue balancing and accurate alignment in total knee arthroplasty (TKA), which are essential for good long-term results. Due to the early-onset severe arthropathy, haemophiliacs undergo prosthetic surgery at a younger age than general population; therefore to ensure a longer duration of implantation is a major objective to be reached in this setting. As several prospective randomised studies could show, Computer navigation in prosthetic surgery improve precision concerning geometry of axes, resection planes and implant alignment, by the determination of joint centres (actual axis), amount of bone resection, size of prostheses and check of ligament balance. At our department, since January 2006, we implanted four TKA in four patients (age range 45–52 years) affected by severe Haemophilia B; the same surgeon used a single system (Orthopilot system) in all cases.

The quality of implantation was studied on postoperative standardized long leg coronal and lateral x-rays. Our results showed that CAS had greater consistency and accuracy in implant placement. Complications influencing the clinical outcome did not occur. In our experience, drawbacks of the navigation systems are the additional costs and the additional operation time between 15 and 25 min. However, one of the most important advantages of using of this technique in patient affected by coagulation disease, according to the international literature, is the reduction of blood loss after operation. A long-term follow-up of these and of larger samples of patients is needed for testing cost/risk-benefit ratio of Orthopilot in prosthetic surgery of haemophiliacs. Therefore navigated total knee arthroplasty in haemophilic arthropathy is not yet a standard procedure, but this technique could become an important surgical choice in management of severe secondary osteoarthritis in the future.