S. Murakami et al., QUANTITATIVE-ANALYSIS OF SYNOVIAL FIBROSIS IN THE INFRAPATELLAR FAT PAD BEFORE AND AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION, American journal of sports medicine, 25(1), 1997, pp. 29-34
We performed quantitative analysis of synovial fibrosis in the infrapa
tellar fat pad in 26 patients who underwent arthroscopically assisted
anterior cruciate ligament reconstructions. Twelve patients underwent
reconstruction with patellar tendon autografts, and 14 had reconstruct
ions with semitendinosus and gracilis tendon autografts. Synovial samp
les were obtained at the time of reconstruction from 10 patients and a
t second-look arthroscopy from all 26 patients. Sections from quick-fr
ozen samples were stained with either hematoxylin and eosin or Fast gr
een and Sirius red. We used sodium hydroxide in absolute methanol to e
lute the Fast green and Sirius red stains, and the total collagen cont
ent of each section was estimated by measuring the optical density of
the eluted solution. The volume of each section was determined on a co
mputer using an imaging program, and collagen content per unit of tiss
ue was calculated. Median collagen content was 15.3 mu g/mm(3) for the
preoperative samples, 25.1 mu g/mm(3) for the group with patellar ten
don autografts, and 27.1 mu g/mm(3) for the group with hamstring tendo
ns autografts. Analysis of preoperative and postoperative paired sampl
es revealed a significant increase in synovial collagen after anterior
cruciate ligament reconstruction. We observed increased fibrosis in p
atients who had pain on exertion or stiffness in squatting after the r
econstructive surgery.