The fate of patellar tendon and infrapatellar fat pad after arthroscopy via central portal

Abstract

Central patellar (CP) portal is an accessory portal in arthroscopic knee surgery, which generally is considered to be safe. In this cross sectional study, we aimed to delineate the clinical and radiological outcome of patellar tendon (PT) and Hoffa's fat pad after the use of this approach. From our hospital records, patients who underwent arthroscopy via CP portal were identified and were invited for the study. There were16 men and 4 women with a mean age of 32 years. Mean follow-up time was 28 months. Meniscectomy had been performed for irreparable bucket-handle type medial meniscal tears in all patients. At the latest follow-up, no patients had anterior knee pain and physical examination was normal. Mean PT thickness of operated knees measured with Ultrasonography was 5.63+/-1.56, while it was 3.76+/-0.46 mm in contralateral knees and the difference was significant. Contour irregularity of PT and focal hypoechoic areas were found in 17 patients, two of which also had hyperechogenic calcification focuses. Abnormal signal intensity of PT was also found in 17 patients with Magnetic Resonance Imaging (MRI). Eleven of these had decreased signal intensity within the tendon which was interpreted as fibrosis. In six patients, increased signal intensity, radiologically similar to chronic tendinitis, was detected. Four patients had decreased signal intensity in the Hoffa's fat pad. Local fibrous tissues in patellar tendon might cause weakness in the tendon. This study showed that although CP portal did not cause any clinical problems in a low demand group of patients, it leads to a significant radiological sequela in the tendon, biomechanical significance of which needs to be clarified.

Ectopic chondro‐ossification and erroneous extracellular matrix deposition in a tendon window injury model

“…15,16,21 Other tendinopathic-like features such as mild degenerative changes, 18 increase in cellularity and vascularity, 17 hypoechogeneity, and hyperechogeneity, 15,20,21 increase in tendon width 15,[17][18][19][20]21 as observed with MRI and ultrasonography have also been reported. Bayar et al 15 further described their patients having changes similar to tendinopathy in 6 out of 20 patients. This suggested that acute injury as created by the removal of the central one-third of patellar tendon could develop tendinopathic-like changes.…”

“…[8][9][10][11][12] Clinical studies have occasionally reported ectopic calcification after Achilles tendon rupture 13,14 as well as calcification and tendinopathic-like changes in patellar tendon donor site after anterior cruciate ligament (ACL) reconstruction. [15][16][17][18][19][20][21] We hypothesized that chondro-osteogenesis and change in the ECM composition of the repair tissue after acute tendon injury might contribute to the poor tissue quality. This study therefore aimed to examine the presence of chondrocyte phenotype and ossification inside the window wound of the patellar tendon.…”

Patellar Tendinopathy

“…3,5,7,8,12,21,28 The precise cause of CaDs in tendons remains unknown. 9 CaDs in the patellar tendon have been found in volleyball 21 and basketball athletes, 5 as well as in postsurgical patients.…”

“…9 CaDs in the patellar tendon have been found in volleyball 21 and basketball athletes, 5 as well as in postsurgical patients. 3,12,28 …”

Reply to the comments on our article “The fate of patellar tendon and infrapatellar fat pad after arthroscopy via central portal”

“…We thank Dr Checa for this important contribution and comments on our article [1], although these two studies are different in terms of methodology.…”