The rational of intra-articular viscosupplementation is based on both the biological and mechanical properties of HA, which exerts positive effects on the modulation of the entire joint environment.

The aim of the present double blind controlled study was to evaluate the effects in terms of pain control and functional recovery provided by a single intra-operative injection of HA performed at the end of arthroscopic partial meniscectomy.

Patients included in this trial were randomized in two treatment groups: the first one received a single injection of HA (Hymovis 24 mg/3ml, Fidia Farmaceutici Spa, Padova, Italy) at the end of the arthroscopic meniscectomy, whereas the second group was treated by surgery alone.

All patients were evaluated basally, at 15, 30, 60, and 180 days after surgery by the following evaluation tools: IKDC (International Knee Documentation Committee) subjective, VAS (Visual Analogue Score) for pain, EQ-VAS for general Health Status, KOOS (Knee Injury and Osteoarthritis Outcome Score) and Tegner score. Furthermore, during the basal evaluation and at each follow-up visit up to 2 months, active and passive Range of Motion (ROM) of both the operated and contralateral knee were documented; also in addition, the trans-patellar circumference of both knees was registered to assess the trend of knee swelling over time.

Inclusion Criteria:

1. chronic symptomatic meniscal tears requiring partial resection;
2. healthy contra-lateral knee (i.e. no pain or functional limitation in the contra-lateral joint);

Exclusion Criteria:

1. previous surgery on the index knee;
2. other concurrent articular lesion requiring surgical treatment (e.g.: cartilage or ligament injuries);
3. history of knee infectious arthritis;
4. concurrent rheumatic, metabolic or severe systemic disease;
5. Body Mass Index (BMI) > 30;
6. known hypersensibility or allergy to/towards HA ;
7. alcohol or other substances abuse/excess.