2015 ISAKOS Biennial Congress ePoster #1932

Degenerative Cartilage Change of Patellofemoral Joint After Anterior Cruciate Ligament Reconstruction

Sang Hak Lee, MD, PhD, Seoul KOREA, REPUBLIC OF
Kyoung-Ho Yoon, MD, PhD, Prof., Seoul KOREA, REPUBLIC OF
Jung Suk Kim, MD, Seoul KOREA, REPUBLIC OF
Kyung Hee University, School of Medicine, Seoul, KOREA

FDA Status Not Applicable

Summary: More larger scar tissue of infrapatella fat pad in postoperative MRI will be cause of more degenerative change of patellofemoral joint.

Abstract:

Purpose

Several reports have been published progression of articular cartilage degeneration of patellofemoral joint (PFJ) after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the prevalence and risk factor of cartilage degeneration of PFJ in short term follow-up period. We hypothesized that larger scar tissue of infrapatellar fat pad (IPFP) and instability will be cause of more degenerative change.

Methods

107 patients form Dec. 2000 to May. 2013, who received ACL reconstruction and underwent postoperative magnetic resonance imaging (MRI) and second-look arthroscopy, were retrospectively reviewed. Average age of the patients was 27.3±9.5 years (range 15–54 years), duration between ACL reconstruction and second look arthroscopy was 28.7±15.8 months (range 7.0–111.0 months). Severity of IPFP scar was evaluated by MRI that was taken an average of 26.2±23.1 months (range 5.0–135.6 months) after ACL reconstruction. Cartilage degeneration was evaluated second look arthroscopy. Instability was checked by anterior drawer test, Lachman test, pivot-shift test, and anterior translation on Telos stress radiographs (Telos, Weiterstadt, Germany), at least 1 year after reconstruction. Insall-Salvati ratio also checked both simple radiograph and MRI at preoperatively and last follow-up.

Results

25 patients (24.0%) showed cartilage degeneration of PFJ in second look arthroscopy. According to severity of IPFP scar tissue, we divided patients into 3 groups. (Group A : focal and incomplete band scar, n=69, Group B : complete band scar, n=31, Group C : diffuse and infiltrated scar, n=7) Cartilage degeneration of PFJ was found significantly worsened with more scar formation of IPFP. (p=0.000, respectively) Side to side difference and anterior drawer test, Lachman test, pivot-shift test were not correlated with cartilage degeneration of PFJ. (p=0.566 in side to side difference, p=0.305 in anterior drawer test, Lachman test, pivot-shift test) Age was also no correlation with cartilage degeneration. (p=0.308) The average value for the Insall-Salvati ratio were 0.96±0.15 preoperatively, 0.95±0.15 at last follow-up in simple radiograph and 0.99±0.16 preoperatively, 0.98±0.14 at last follow-up in MRI. Insall-Salvati ratio was no statistically significant difference both simple radiograph and MRI. (p=0.296 in simple radiograph, p=0.473 in MRI)

Conclusions

More larger scar tissue of infrapatella fat pad in postoperative MRI will be cause of more degenerative change of patellofemoral joint. Instability and age did not affect cartilage degeneration of PFJ in short term follow-up period.