Diagnostic Value of Computed Tomography and Risk Factors for Lateral Hinge Fracture in the Open Wedge High Tibial Osteotomy.PURPOSE
 The purposes of this study were to evaluate (1) the disparity of detection of lateral hinge fracture (LHF) between postoperative simple radiography and high-resolution computed tomography (CT) and affecting factors of LHF and (2) whether generally recommended postoperative rehabilitation protocols are appropriate according to the type of LHF.


 From 2014 to 2015, patients who underwent primary open wedge high tibial osteotomy (OWHTO) for isolated medial compartment osteoarthritis of the knee joint were retrospectively enrolled.  The incidence of LHF after OWHTO based on simple radiographs was compared with its incidence based on CT scans.  Twenty-three cases (24.5%) of LHF after 94 OWHTOs were detected (15 cases on simple radiographs, 8 cases on CT scan).  The correction loss of the hip-knee-ankle angle and the medial proximal tibial angle in the LHF group was significantly larger than those in the non-LHF group (1.3° ± 1.8° vs 0.4° ± 1.4°, P < .001; 1.3° ± 1.1° vs 0.7° ± 0.9°, P = .009, respectively).


 Further evaluation with CT scanning is highly valuable immediately after all OWHTO because of its higher detection rate (24.5%) of LHF compared with simple radiographs (16%).  Finally, the LHF should be managed conservatively in order to prevent postoperative correction loss.



CT