Double-Level Osteotomy in Severe Varus Malalignment to Optimize Knee Joint Restoration.

Background: Lower extremity alignment-correcting procedures for unicompartmental osteoarthritis are experiencing a rapid rise. Medial open-wedge high tibial osteotomy (MOW-HTO) thereby represents the most common technique among osteotomies but is limited in cases of severe malalignment. Some cases make a double-level osteotomy necessary. Indications: If planning of malalignment correction using a MOW-HTO results in a mechanical medial proximal tibial angle (mMPTA) of more than 93° (causing an oblique joint line), double-level osteotomy is indicated to avoid nonphysiological knee kinematics. Technique Description: After clinical examination and detailed analysis of malalignment (full-weight-bearing long-leg radiograph: hip-knee-angle [HKA], mMPTA, mechanical lateral distal femoral angle [mLDFA], joint line convergence angle [JLCA]), as well as individualized planning of the correction, the surgical procedure starts with an arthroscopy to evaluate the cartilage conditions and eventually treat intraarticular pathologies. Then, the femoral supracondylar correction is performed (closed wedge, biplanar osteotomy [ Results: In recent literature, only few publications report on results of double-level osteotomies. Babis et al reports that it is a valuable procedure for patients with large varus deformity. Nakayama et al noted a significant improvement in patient-registered clinical outcomes in early postoperative evaluation of 20 patients. Schröter et al reports on 37 knees and findings include good clinical results, despite progressive osteoarthritis. Discussion/Conclusion: In cases of severe malalignment, adequate axis correction may require a double-level osteotomy. Exact preoperative planning is essential. Results reported in recent publications are promising. By splitting 1 large correction into 2 smaller ones, complications like hinge fracture and delayed bone healing are lowered.