chapter 10: Patellar Dislocation

Fulkerson's Approach to Acute Patellar Dislocation

When there is radiographic evidence of an osteochondral fragment in the knee, do an arthroscopy to locate the fragment and replace it if it is large enough. Pinning the fragment back to the trochlea generally requires a limited lateral arthrotomy, at which time a lateral release will normally be done if there is patellar tilt. If there is a small fragment (<1 cm articular diameter), the fragment is usually removed arthroscopically. If the patient has evidence of significant lateral patellar tilt, a lateral release is done. We emphasize tilt because we agree with Christensen et al (38) that lateral release alone is not consistently helpful for patients with subluxation (39).

However, if acute patellar dislocation has been a result of direct trauma without underlying malalignment, there is no reason to do a lateral release. Also, if there is no evidence of bone attached to a loose fragment, there is little reason to operate acutely inasmuch as replacement of cartilage alone will be destined to failure in the majority of cases.   Nonetheless, when there are fragments of bone attached to a significant piece of articular cartilage, one should make an effort to restore the joint surface.  At times, one may wish to use fine(6-0) suture to stabilize articular edges and allow fragment healing .

In short, then, we recommend a logical approach to these patients. Replace fragments that have been dislodged from the lateral trochlea or patella. Do a lateral release when there is evidence of a predisposing tilt. When there is no major osteochondral fragment or clear malalignment, treat the patient with immobilization initially, followed by progressive quadriceps exercise emphasizing the vastus medialis obliquus, and mobilization of the knee using a patella buttress brace.  The author prefers his own design brace, the Trupull Lite (DJO, Vista, CA)






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