chapter 8: Patellar Tilt‑Compression and the Excessive Lateral Pressure Syndrome (ELPS)


Patient 1 (32‑year‑old female hairdresser)

This patient has spontaneous onset of pain in both knees, left more than right, 3 years before first being seen. One and one‑half years after the onset, she noted swelling in both knees at the end of the day standing at work, which was associated with a sense of heaviness in the knees. Going up and down stairs particularly increased the pain. On examination: Flexion‑extension was full, there was no ligamentous laxity, and there were no meniscal signs. There was pain on compression of the lateral facet and on extension against resistance. The patella tracked normally on clinical examination. Crepitus could be felt on moving the patella both longitudinally and transversely in the trochlea. Transverse movement, that is, the patellar play, was decreased. The patient was unable to squat. Physical signs were identical on both sides. Radiograph: AP, lateral, and axial views were all within normal limits. Bilateral lateral retinacular releases were done. Operative findings (Fig. 8.17): right knee, Outerbridge Grade 3 findings on the lateral facet, with fissures and softened cartilage. The patellar surface was debrided of loose cartilage; left knee, Outerbridge Grades 3 to 4 changes, more extensive than the right, affecting the entire medial and lateral facets, with one long horizontal fissure extending from the median ridge into the lateral third of the lateral facet. Secondary stellate fissures reached subchondral bone along nearly the entire lateral border; patellar debridement was coupled with subchondral perforations. Postoperative course was uncomplicated. The patient returned to work 2 months after the surgery. Follow‑up at 1 year: the patient continued to work, but also continued to have pain and swelling at the end of a day's work and some difficulty with stairs. Because of the advanced arthrosis, this patient may be a candidate for patellar anteriorization. The right knee would be particularly amenable to anteromedial tibial tubercle transfer to shift contact stress from the arthritic lateral facet onto better medial cartilage and reduce overall load. In retrospect, a CT scan might have revealed tilt of the patellae in early flexion, at which time a decision to do lateral release in addition to debridement would have been appropriate. In view of the advanced cartilage changes, initial tibial tubercle anteromedialization might have eliminated the need for reoperation.





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