Repairs by trephination and suturing of longitudinal injuries in the avascular area of the meniscus in goats.

Trephination may encourage healing of a tear in the avascular area of the meniscus, but healing may not be complete in unstable tears. We studied trephination with suture of longitudinal injuries in the avascular area of the medial meniscus in 20 goats; samples were studied at 3, 8, and 25 weeks. All 20 tears treated by trephination and suture were completely (4 samples) or partly (16 samples) healed. The average tensile strength of the healed repair was 40.4 kg/cm2 at 25 weeks. The level of DNA synthesis and tissue ingrowth decreased with time; DNA synthetic activity was also found in the chondrocytes of the menisci treated by suture alone. Only three of the menisci treated by suture alone were partly healed, and the remainder showed no gross evidence of healing. The addition of trephination to the sutured meniscus appears to promote healing of longitudinal injuries in the avascular area and is recommended rather than suturing or trephination alone. Meniscal suture alone may stabilize the tear and stimulate cell proliferation for healing, but it appears to be significantly restricted without an adequate blood supply.