Fabella Fractures after Total Knee Arthroplasty with Correction of Valgus Malalignment

Figure 2

Preoperative (a, b) and immediate postoperative (c, d) knee radiographs in a 68-year-old woman who underwent total knee arthroplasty of the right knee because of symptomatic knee osteoarthritis with valgus malalignment. Preoperative knee radiographs (anterior-posterior view of both knees (a) and lateral view of the right knee (b)) show osteophytes, sclerotic changes, and some degree of generalized joint space narrowing on both sides, in keeping with femorotibial osteoarthritis. There is approximately 10° valgus malalignment of the right knee and approximately 14° valgus malalignment of the left knee. Note the normal appearing fabella ((b) arrowhead). Immediate postoperative radiographs of the right knee on the same day of surgery (anterior-posterior view (c) and lateral view (d)) show not only a good position of the total knee arthroplasty with a well-aligned knee joint but also a horizontal fracture through the fabella with only minimal dislocation ((d) including magnified view of the fabella).

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