Postoperative pain is part of surgery trauma. In orthopedic surgery artroplastic replacement of knee- and hipjoints are common. Postoperative pain relieve can be complicated. A new concept for pain relieve postoperative is local infiltration analgesia (LIA). This technique implicates that a catheter is left in the surgical area and that local anestesia can be administered post surgery. The goal is no or only little pain with minimal side effects. The catheter could be placed intra- or extracapsulare. The best position is not known. Primary aim is to study if position of the catheter effects the need of other postoperative analgesia. Secondary aim is to study if the position effects patient mobility within the first two days.

Inclusion Criteria:

• Patients undergoing arthroplastic surgery of knee or hip

Exclusion Criteria:

• Sensitivity to local anesthetics
• Other reason not to use local anesthetics