Free synovium promotes meniscal healing. Synovium, muscle and synthetic mesh compared in dogs.

We studied the effect of free synovium on the healing of tears in the avascular portion of the menisci in dogs. A longitudinal incision was made in the medial meniscus. In 35 dogs, a free graft of synovium was inserted into the tear and sutured. In 10 dogs, a free graft of quadriceps muscle was used. In 10 dogs, a Dacron mesh was inserted. In the contralateral knee, the tear was sutured without implantation as a control. 2, 4, 6, 8, and 12 weeks after the operation, the menisci were dissected. 11 of the 35 with free synovium were healed. The menisci with muscle grafts, those with Dacron mesh and those in the control group did not heal. Histology showed that tears were repaired with fibrous tissue. Microangiography showed that capillaries grew from the periphery, but they did not reach the tear.

Axial parameters affecting lower limb alignment after high tibial osteotomy.

Lower limb alignment of 46 knees treated with high tibial osteotomy was studied to find a method for determining the precise correction angle. The femorotibial angle was divided into several axial alignment parameters. Before the operations, the femorotibial angle correlated with the tilting angle of the femoral shaft toward the horizontal (femoral shaft-horizontal angle) and that of the tibial shaft toward the horizontal (tibial shaft-horizontal angle). After the operations, the femorotibial angle correlated with the tibial shaft-horizontal angle, but not with the femoral shaft-horizontal angle. The postoperative femoral shaft-horizontal angle tends to be constant regardless of the degree of valgus. In preoperative varus knees, the varus deformity increases the degree of shift of the femoral and tibial shaft toward the varus direction. In postoperative valgus knees, the more valgus the knee the more the tibial shaft shifted toward the valgus direction, which was not true for the femoral shaft. The femorotibial angle was influenced more by the tibial axial alignment in the postoperative valgus knee. The slope of the distal femoral articular surface influenced the tilt of tibial articular surface toward the horizontal which, in turn, influenced the tibial shaft-horizontal angle. The authors recommend relying on the tibial axial alignment parameter to determine the amount of correction. The slope of the distal femoral articular surface should be considered in preoperative planning.

Second look arthroscopy after meniscal repair. Factors affecting the healing rate.

Second look arthroscopy was performed on 46 of 137 consecutive patients who underwent arthroscopic meniscal repair. All tears were of the vertical type. Thirty-two tears were located in avascularized areas. Thirty-one patients had associated anterior cruciate ligament insufficiencies. Anterior cruciate ligament reconstructions were performed simultaneously on 26 patients. The double-needle cannula method was used in all the patients. An additional transplantation of a vascularized synovial pedicle flap to the suture site was performed on 7 tears in avascularized areas. Second look arthroscopy showed no healing in 8 patients and healing in 38. Four of the 8 unhealed tears were located in avascularized areas, and 4 had unreconstructed anterior cruciate ligament injuries respectively. All 7 patients with synovial pedicle flaps showed healing. All patients with anterior cruciate ligament reconstructions showed healing, and the healing rate was significantly higher than that of the other patients (p < 0.005). Patients with anterior cruciate ligament insufficiencies showed a significantly lower healing rate than the others (p < 0.005). In patients with tears in avascularized areas, the conventional meniscal repairs showed a lower healing rate than did the repairs with a synovial pedicle transplantation or an anterior cruciate ligament reconstruction (p < 0.005). These results suggest that the most important factors influencing meniscal healing are the presence of anterior cruciate ligament tears, ligamentous reconstruction, and vascularity of the tear site.

Untreated acute anterior cruciate ligament tears of the knee: progression and the influence of associated injuries.

Arthroscopy was performed on 53 consecutive patients with acutely torn ACL within two weeks after the initial injury. Arthrography was performed on 42 of the 53 patients prior to arthroscopy. Four Segond's fractures, twenty-six meniscus tears (eight medial, eighteen lateral) and nineteen medial collateral ligament (MCL) ruptures were revealed. One medial meniscectomy was performed under arthroscopy, and ten MCL tears were repaired in the acute phase. No surgical procedure was done on the torn ACL, but three excisions of ACL stubs were performed due to a restriction of full extension. The patients were re-examined clinically and radiographically after a period of from 3 years 7 months to 11 years 1 month, averaging 6 years 2 months. Four late meniscectomies were performed on the medial menisci in the chronic phase. Anterior translations of the tibia and knee rating scores of the patients with MCL tears and with Segond's fractures did not differ from those of the others. Anterior translations of the tibia in patients with medial meniscectomies increased (P < 0.05), and their functional scores significantly decreased (P < 0.01) more than those of the other patients. Patients with repaired MCL tears showed significantly higher functional scores than those of the patients with unrepaired MCL ruptures (P < 0.05).

Meniscal repair using a flap of synovium. An experimental study in the dog.

The healing process of longitudinal lesions in the avascular region of the meniscus was investigated in 42 menisci from 21 dogs. A longitudinal incision was made in the avascular portion of the medial menisci of 21 dogs. In one knee, a flap of synovium was sutured into the wound, and in the other, the wound was sutured as a control. Animals were killed after 1 to 12 weeks, and the menisci were removed and examined by gross inspection, light microscopy, and microangiography. In the control knees, no healing had occurred. In 19 of 21 knees in which a synovial pedicle was used, the suture site did not open at any of the postoperative weeks. The longitudinal lesion was repaired with fibrovascular tissue at 6 weeks, and the vessels over the femoral surface of the menisci and an inner portion of the menisci had reached the suture site. The healing of meniscal lesion occurred due to the use of the vascularized synovial pedicle flap and the neovascularization from the parameniscal area.