Fabella Fractures after Total Knee Arthroplasty with Correction of Valgus Malalignment

Figure 3

Preoperative (a–c), immediate postoperative (d, e), and 45-day postoperative (f, g) knee radiographs in a 63-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 (a) and lateral views (b, c) of both knees) show osteophytes, sclerotic changes, and severe joint space narrowing of right-sided lateral and left-sided medial femorotibial compartments, in keeping with femorotibial osteoarthritis. There is approximately 23° valgus malalignment of the right knee and approximately 7° varus malalignment of the left knee. Note the normal appearing fabellae ((b) and (c) arrowheads). Immediate postoperative radiographs of the right knee on the same day of surgery (anterior-posterior view (d) and lateral view (e)) show a good position of the total knee arthroplasty with a well-aligned knee joint and with a still normal appearing fabella ((e) arrowhead). However, 45-day postoperative radiographs of the right knee (anterior-posterior view (f) and lateral view (g)) show a shattered patella ((g) including magnified view of the fabella).

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