Introduction: Drainage of the surgical wound following major surgical procedures is advocated to avoid haematoma formation. Recently the need for of wound drainage in joint arthroplasty has been questioned. The aim of this prospective randomised study is to determine the benefits of a postoperative closed-suction drain after UKR.

Material and Methods: In a prospective randomised trial we evaluated the use of a postoperative closed-suction drain in unicompartmental knee replacement. Seventy-eight patients were divided into two groups: one without a postoperative closed-suction drain (Group A) and one with a drain (Group B). Both groups were matched for age, sex, and pre-operative haemoglobin.

Results: In group A we observed a lower day one postoperative analgesic requirement, smaller knee circumference 3 days postoperatively and less local wound complications. No deep infections occurred in either group during the follow-up period. Drain usage in UKR resulted in no significant advantage in postoperative pain, range of motion, and hospital stay. Post-operative drainage does however increase the cost of the procedure both in labour and equipment expenditure.

Conclusions: We conclude that avoiding postoperative closed-suction drainage in UKR does not influence the final outcome.

Introduction: Nowadays bicompartimental arthritis of the knee in patients younger than sixty still remains a challenge for the orthopaedic surgeon. In these selected cases, the authors present their experience in performing a mini-invasive bi-unicompartimental knee replacement assisted by computer navigation.

Materials and Methods: From January to December 2003, the authors treated 7 patients (7 knees) with bicompartimental arthritis of the knee. The mean age was 66 and in all the cases there was a arthritis deformity with no ligament deficiency and a pain-free femoro-patellar joint. The Orhopilot (4.0 version) navigation system was used during the surgery to assist prosthesis placement. In all the cases a minimal surgical approach was used (7 to 9 cm skin cut). The patients were assessed using a UKR dedicated outcome score (G.I.U.M. Score), pre-operatively and at the latest follow-up. Pre-operatively the mean GIUM score was 49.1 (range 26–63)

Results: At the lastest follow-up the mean GIUM score was 80.2 (range:75–94). The average femorotibial angle was 179° (range 177° −181°). A good ligament balance was achieved In all cases using a computer assisted spreader device. All the patients were satisfied and had returned to their previous occupation soon.

Conclusions: The authors underline how the computer navigation system supports ligament balancing and a correct prosthesis alignment. They registred no fracture of the tibial intercondylar eminence cause of wrong balancing and cuts. They emphasize this real mini-invasive surgical approach to the cure of the knee arthritis, above all in young patients with post traumatic deformities.