2 Clinical and radiological evaluation
1 Clinical examination
Patient history and clinical examination are the baseline of any preoperative work up for osteotomies around the knee. History of trauma or previous surgery and professional activity and sports, are of special interest. The expected patient activity level is to be considered. Contraindications such as nicotine abuse, which often leads to delayed consolidation of the osteotomy, overweight, rheumatoid arthritis, and patient age over 60-70 years, where knee arthroplasty leads to better results [1, 2], must be ruled out. Nevertheless, consideration of biological age should take priority over chronological age.
Clinical examination includes evaluation of soft tissue and skin as well as vascular and neurological status of the lower extremity. Systemic or local infection should be ruled out.
The range of motion of the knee should be inspected. At least 120° of flexion and not more than 20° extension deficit are mandatory. Anteroposterior and mediolateral ligamenteous stability should be examined and the leg length must be inspected. The alignment of the lower extremity is evaluated under full weight bearing and in the supine position. If the medial compartment is involved, movement under varus stress is painful, whereas valgus stress should reduce pain.
The authors classify three different groups of patients which can be treated by osteotomy around the knee:
Patients with unicompartmental arthritis
Patients with malalignment of the leg and ligamenteous instability of the knee
Patients with complex deformities
1.1 Unicompartmental osteoarthritis
The most common group of patients presents with unicompartmental medial or lateral femorotibial osteoarthritis. These patients complain about pain in the affected joint compartment during weight bearing. If pain is not located exclusively either over the medial compartment or the lateral joint space, the indication for osteotomy should be reconsidered. Femoropatellar pain with significant degenerative changes of the cartilage is considered as a relative contraindication for osteotomy. Special attention should be addressed to the subjective pain level, for example with the visual analog scale (VAS). In the authors’ experience, patients suffering higher pain levels often have less relief and benefit from osteotomy.
1.2 Knee instability
Another group of patients that can be treated by osteotomy around the knee are patients with varus malalignment of the leg and ligamenteous instability of the knee. Signs of cartilage damage in the medial joint are often present in these patients. In contrast to patients with osteoarthritis, where pain is the leading symptom, instability and giving way of the knee is prominent. Combined procedures with correction osteotomy and ligament reconstruction or two-plane osteotomy (valgization-flexion or valgization-extension osteotomy) are established treatment methods for these patients (see chapter 11 “Osteotomy and ligament instability: tibial slope corrections and combined procedures around the knee joint”).