To clarify the meaning the patellar tenderness for the patellofemoral osteoarthritis we compared intraoperative findings of the wear pattern of the articular cartilage of the patella and corresponding femoral trochiea with preoperative patellar
tend4erness in cases of total knee arthroplasty. The tenderness was observed according to the divided area such as inferior pole, lateral facet, central ridge, medial facet and superior pole. The wear pattern of the articular cartilage was also
on
the
aforementtioned divided area. One hundred and twelve knees of 73 patients were involved in this study.
The average age of the patients was 61.8 years ranging from 30 to 80.
The sex was predominently female (67 patients, 91.8%).
Position of the patella was measured with Insall-Salvati measurement and Blackburne-Peel measurement. From a Merchant´s view sulcus angle and congruence angle were measured. The relationship of those findings and the wear pattern was analyzed
statistically with chi-square test.
1. Wear of the cartilage was near or at the central ridge, from, which it was extended medially, laterally and distally. No case showed isolated wear of inferior pole or superior pole.
2. Patellar tenderness was most frequently observed at inferior pole followed by lateral facet and then central ridge. However, there was no isolated tenderness on central ridge where wear of the articular cartilage was seen, Tenderness on the
proximal
pole was frequently observed independently. The tender point was not coincided with the wear area at all.
3. There was no significant relationship between congruence angle and patellar tenderness or wear of cartilage (P>0.05).
4. Wear of the articular cartilage of the trochlea could occur without wear of the of the cartilage of the patella, however there was no statistical relationship between the two (P > 0.05). Radiological subchondral sclerosis was not
significantly
related with the findings of wear of the cartilage (P > 0.05), whereas subchondral cyst was seen more frequently in case of intact cartilage (P < 0.05).
From these results it was suggested that the patellar tenderness could not be a index of the severity of the wear of articular cartilage of the patella. The patellar tenderness may be caused by other factors other than cartilage wear, such as
synovial
impingement or spur.
|