This study will compare meniscal healing augmented or without augmentation with platelet rich plasma in primary meniscal tear treatment (prolotherapy). The assessments will include validated, disease specific, patient oriented outcome measures. Results of this study will help ascertain whether platelet rich plasma may improve meniscal healing rates.

The role of meniscal in the knee integrity is pivotal and lack or partial role of the meniscus increases rate of joint degeneration. Partial meniscal removal is the most popular procedure and meniscal repair remain in minority of arthroscopic surgeries. As criteria of inclusion to meniscal repair are very rough, still success rates of meniscal repair remain in the 60-80% range for isolated repairs. This rate is greater when performed with ACL reconstruction. The investigators believe that augmentation with platelet rich plasma as prolotherapy ill induce healing without the need for arthroscopy.

Inclusion Criteria:

• Complete horizontal 10 mm in length
• Tear located in the vascular/avascular portion of the meniscus (chronic horizontal tear on MR)
• Single tear of the medial and/or lateral meniscus
• Skeletally mature patients 18-70 years of age

Exclusion Criteria:

• discoid meniscus
• arthritic changes (Kellgren Lawrence scale >2) or axial leg deformity (valgus > 6 deg)
• inflammatory diseases (i.e. rheumatoid arthritis)
• concominant chondral defects (> 2 ICRS)