Transplantation of fresh-frozen menisci: an experimental study in dogs.

Transplantation of 25 fresh-frozen medial menisci was studied in 15 adult dogs. Before implantation, the allografts were deep-frozen and stored at -70 degrees C for 6 weeks to 18 months. The animals were killed 2 to 8 months postoperatively, and their knees and transplants were examined macroscopically and histologically. Complete healing of the allografts was found in 19 knees, incomplete in 3, and healing by massive fibrovascular tissue in 3 knees. Some shrinkage of the transplants taken 2 to 4 months after the surgery was observed; however, the 6- and 8-month specimens appeared grossly normal. Histologically, all transplants displayed a characteristic decrease in the number of cells, but this was significantly less pronounced in the 6- and 8-month specimens. Some degenerative alterations were found in all transplanted knees, but was obviously less pronounced in areas covered by the allografts and in the 6- and 8-month specimens. It is concluded that the transplantation of the fresh-frozen menisci could be successful; although the transplants are subjected to a remodeling process, they appear to function normally and protect the articular cartilage. The technique of conservation by freezing at -70 degrees C offers the advantage of an effective meniscal banking.

[Fracture of a transfixed intramedullary nail in a patient with pseudoarthrosis of the femoral diaphysis]. / Prelom transfiksiranog intramedularnog klina u bolesnika s pseudoartrozom dijafize femura.

This is a case report on a patient with a multiple femur's fracture where a transfixed intramedullar nailing of Grosse-Kempf type has been done. "The nail dynamization" was not carried out before the beginning of vertical loading. Seven months after the full vertical loading had begun, at a sudden torsian movement of the extremity, the nail had broken. Analyzing the cause of the fixative material fracture, a conclusion has been made that, apart from the presence of adequate trauma, the nail fracture happened also due to the development of pseudoarthrosis of femur and the unfulfilled "nail dynamization".

Allograft meniscus transplantation in the dog.

We studied transplantation of a fresh meniscus in 25 knees in 15 adult dogs. On 2 tables and with 2 surgical teams the medial menisci were explanted, exchanged and implanted into the opposite dog's knee. The animals were killed 4-12 months postoperatively, and the transplants were studied histologically. Complete healing in the host's capsular tissues was found in 18 knees, incomplete healing in 3, and healing by massive fibrovascular scar tissue in 4 knees. In the 4- and 5-month specimens the transplants were found to be narrower, thinner, and of changed color and consistency, while in the 8- and 12-month specimens most of the allografts appeared grossly normal. Histologically, the allografts had normal general microarchitecture, but a marked decrease in the number of cells. In the 8- and 12-month specimens the cells had increased but the number of cells in general was still less than in the controls. Although some degenerative changes of the medial tibial articular cartilage were noted in most knees, there were less changes beneath the allografted meniscus.

[Transplantation of the meniscus in dogs--preliminary report]. / Transplantacija meniskusa u psa--preliminarno saopstenje.

A preliminary investigation of the allogenic transplantation of the meniscus without the vascular bundle was carried out in 4 adult dogs with 8 knees. In one operation session on 2 dogs at 2 operative tables and with two operative teams an identical surgical procedure in general anaesthesia was done. A medial parapatellar incision of the knee was used, the medial capsule and the collateral ligament near its proximal insertion were severed. Explanted medial menisci were exchanged and the meniscus from the other dog was put in position of the explanted one and fixed with 3 tangentially placed sutures (posterior, medial and anterior) which were taken out through the capsule and teid extra-articularly; there was no immobilisation, and after 3 weeks the identical operation was done on the other knee. The animals were sacrificed 4-5 months after the operation, the knees were dissected and observed. In all 8 knees transplanted menisci were completely healed around their periphery, however their appearance was rather changed. They were narrower, thinner, and of different colour and consistency. The transplanted menisci were removed and conserved in 10% (formalin) for the further investigation. It is concluded that the allogenic meniscal transplantation without the vascular bundle is possible and that the further investigation of this problem is justified.

[Revascularization of the forelimb in dogs]. / Revaskularizacija podlakta u psa.

Revascularization of the forearm was performed on six mature dogs of a different race. Arteria mediana was cut 2 cm above the fork of the arteria radialis and later sutured with a nonresorptive monofilament thread/Ethilonr/7-0 and 8-0 in diameter. The same process was repeated on the cefalica vein. Arteriographies were performed on the operated extremities, pre-operatively, immediately after operation and while an animal being sacrificed. The subjects were sacrificed six months after the operation. Then microscopic and histological analyses were carried out to assess the quality of the blood vessels at the suturing place. At the place of the blood vessels reconstruction, lumen did not get narrower which indicated that all the vessels were in a perfect functional condition. In a number of dogs a higher collagenic proliferation was noticed, in the vicinity of the blood vessels sutured. In the regenerative process of the arterial wall tunica mediana almost took a predominant position, like in the intact arteria. All the three strata were present with no relevant deviations in structure. In the cefalica vein the regeneration of the connective tissue support of the smooth muscles cells was insufficient. Based on the analysis of the results obtained it might be concluded that after revascularization of the forearm of the dog the regeneration of the blood vessels made the segment functionally capable with the structure not different from the normal one which existed in the blood vessels of the same part of the body.