Clinical Research Directory

Inclusion Criteria: * Patients having accepted and signed the informed consent form before surgery * Patients aged 30-60 years * Patients with an indication for primary HTO based on anamnestic, clinical and radiological findings leading to the diagnosis of major medial knee compartment overload symptoms * Mechanical varus axis of 3-9 deg. (calculated on full length weightbearing X-ray (FLWB)) * Correctable angular deformity on the tibia only (medial proximal tibial angle (MPTA) + planned correction \< 95 deg. Lateral distal femoral angle (LDFA) \<92 deg.) * Maximal calculated gap height 14 mm * Only the first knee will be included if later contralateral HTO Exclusion Criteria: * Inflammatory arthritis (Rheumatoid Arthritis, Bechterew arthritis, Psoriatic Arthritis) * Patients using Prednisolone perorally * Smokers (need to quit preoperatively) * Significant overweight (Body Mass Index \> 35) * Earlier fractures in affected leg with fracture malalignment \>5 deg. * Extension deficit \>10 deg. in the affected knee * Earlier septic arthritis/osteomyelitis in the affected leg * Previous major surgery affecting leg function. Earlier knee arthroscopic procedures like ACL-reconstruction are not excluded * Planned combined procedures involving HTO + ACL/PCL-reconstruction, meniscal transplantation or meniscal root fixation is excluded * Neurologic disease with symptoms affecting the leg * Serious illness or other factors that make communication, follow-up or rehabilitation difficult (e.g. alcohol or drug abuse, psychiatric disease, non-Norwegian speakers).