Ninety patients are involved in this study, who underwent arthroscopic lateral patellar release for lateral patellar compression syndrome and they had patellofemoral degenerative lesion, which diagnoses by MRI preoperatively and proved by arthroscopic examination to be early stages of degenerative changes with no loss of articular surface. The patients were divided in to two groups (A and B). Group A (45 patients) were treated by local injection of Hyaluronic acid intraarticularly, and Group B (45 patients) were no injection intraarticular.

This study was done by one orthopedic surgeon in two hospitals. Ninety patients are involved in this study, who underwent arthroscopic lateral patellar release for lateral patellar compression syndrome and they had patellofemoral degenerative lesion, which diagnoses by MRI preoperatively and proved by arthroscopic examination to be early stages of degenerative changes with no loss of articular surface. The patients were divided in to two matched groups (A and B) regarding the age and gender; Group A (45 patients) were treated by local injection of Hyaluronic acid intraarticularly, 2 weeks after arthroscopy and were followed by VAS of knee pain for one year at (3) months, (6) months and (12) months, and Group B (45 patients) were no injection intraarticular. The study started on June (2017) and ends on March (2020). injection of Hyaluronic acid was used and followed in the same way. All patients presented with anterior knee pain which failed to respond to conservative treatment for 6 weeks or recurrent of symptoms after stopping of conservative treatment which involved changes of life style and NSAID. MRI done for all patients before operation.

Inclusion Criteria:

• Lateral patellar compression syndrome

Exclusion Criteria:

• Patellar instability.
• Smoking.
• Diabetes Mellitus.
• Previous knee surgery.