Scientific Background: Adult articular cartilage, critical to proper joint function, has minimal self-repair ability. No adequate repair technique exists for large defects.

Cryopreservation which is a process of deep-freezing of cells and tissues, enables the preservation of a high proportion of cells when the tissue is thawed and implanted.

Aim: To evaluate a novel method for cryopreservation of articular cartilage in the form of osteochondral sheep cylinders.

Materials and Methods: Osteochondral cylinders, 9mm diameter x 15mm length, were drilled from fresh cadaver sheep knee condyles. A bank of harvested cryo-preserved osteochondral cylinders was created. 17 sheep were used for transplantation. The thawed cylinders (allografts) were transplanted into the medial femoral condyle of the knee while the lateral femoral condyle received the fresh cylinder autograft as a control. The sheep were followed up for one year, following which in-vitro studies were performed to assess for articular cartilage viability.

Results: Clinically, histologically and radiologically there was almost 100% incorporation of allogenic osteochondral cylinders involving most of the weight-bearing area of the sheep knees.

Conclusion: Osteochondral cylinders can be successfully frozen and then transplanted into sheep knees with regeneration of knee function. Successful cryopreservation of human cartilage will be a major breakthrough in the treatment of cartilage lesions.

The importance of meniscal tears repair is discussed widely in the literature. The repair should be performed if the conditions promise some chance for healing. Due to technical difficulties many orthopaedic surgeons still prefer partial meniscectomy to meniscal repair.

We describe our techniques for meniscal repair. The described techniques could be used by any surgeon with basic skills in arthroscopic surgery. No special equipment is needed.

The basic equipment for this technique is a standard 18 gouge needle. The plastic cup of the needle is cut away in order to overcome the ridge between the plastic and the metal part of the needle, thus making the suture passage easier.

Following the arthroscopic identification of the meniscal tear and preparing the torn parts for repair, the place for the first suture is identified.

A 2–3 mm long skin incision is made. The subcutaneous tissue is bluntly developed to the capsule. The 18 gouge needle is past from outside-in in the desired point through the torn margins of the meniscus. The tip of the needle is emerged above or under the meniscal surface, depends on our decision of suture position.

1st step – Producing a loop outside the joint: Two ends of a nylon 2/0 suture are inserted through the needle into the joint cavity, and pulled out through one of the arthroscopic portals. The needle is removed. The result of this step is a nylon 2/0 suture passing through the torn parts of the meniscus with a loop outside the joint.

2nd step – Producing a double-loop inside the joint cavity: A second nylon 2/0 suture is passed through the first loop. The first suture is pulled into the joint. At this stage, both loops are inside the joint, holding each other. The free ends of the first loop are emerged through one of the arthroscopic portals, while the free ends of the second loop pass through the torn parts of the meniscus and emerge through the capsule.

3rd step – Producing the meniscal suture: A second 19 gouge needle is inserted close to the point of insertion of the first one, directed into the joint. The emerging point of this needle, on the meniscus, should be positioned according to the desired suture direction (transverse, vertical, or oblique). The tip of the needle is then directed into the “2nd” nylon loop (the “1st” nylon loop can assist at this stage). The loop is wrapped over the needle, and the 1st suture is removed.

PDS suture (1/0 or 2/0) is inserted through the needle until a 5 cm free end is positioned intra articular. The needle is removed with caution without pulling the PDS suture, leaving the

PDS free end inside the nylon loop. The nylon loop is used as a pooling tool for the PDS suture. Pulling the free end of the PDS suture out of the joint results in a PDS loop for the meniscal suture (in order to avoid iatrogenic tear of the meniscal tissue while pulling the sutures, a probe should be positioned under the PDS suture during the process). The PDS is tightened over the capsule. The technique is repeated as much as necessary for perfect repair of the meniscus.

The advantage of this method is that it does not necessitates unique equipment, but rather uses the ordinary arthroscopic tools and sutures. This method was used successfully upon large number of meniscal tears. We recommend its use routinely.