OBJECTIVE To investigate the effect of meniscus suture on meniscus healing which included healing time and healing pattern. METHODS Fourty healthy rabbits were adopted in this study. The model of meniscus injury was made by a longitudinal incision at the medial meniscus of the left knee. The rabbits were divided into two groups, the experimental group was treated by meniscus suture and the control group was unsutured. After operation, the meniscus samples were collected periodically and observed by gross, light and electronic microscope to analysis the meniscus healing. RESULTS The injured meniscus was healed gradually and completely at the sixth week in the experimental groups. More fibroblasts and less fibrocartilage cells could be observed in the healed meniscus. Oppositely, there was no meniscus healing in the control group and the edge of injured meniscus was sealed by epithelioid cells. CONCLUSION The meniscus suture can accelerate the healing process of meniscus injury. Besides, early suture make the injured meniscus correctly positioned to ensure the normal healing process.
Objective To study degradation of the antigen-extracted meniscus in PBS solution with no enzyme or with different enzymes. Methods Four types of enzymes (collagenase, hyaluronidase, trypsin, papain) were used to enzymolyze the antigen-extracted meniscus and the fresh meniscus for 3, 7, 15 and 30 days (37℃). The antigenextracted meniscus and the fresh meniscus were immersed in PBS solution (37℃) for 30 days. Weight loss measurement, UV spectrophotometry, and scanning electron microscopy (SEM) were used to characterize the degraded materials. Results The two types of the materials were remarkably digested under the enzymes, especially under trypsin. The degradation curves showed that the antigen-extracted meniscus was enzymolyzed less than the fresh meniscus. The degradation products were grouped as amino, peptide, and polyose by the analysis. Both of the materials could hardly behydrolyzed in PBS solution without the enzymes. The four different enzymes had different surface morphologies under the examination of SEM. Conclusion The antigen-extracted meniscus is enzymolyzed more slowly than the fresh meniscus in vitro, and the result can be used as a guideline to the further research.
Objective To review the details of the current effortsto reconstruct or replace the meniscus.Methods Three kinds of proceduresof reconstructing or replacing the meniscus were analyzed and evaluated by an extensive review of the latest literatures concerned. Results Three kinds of techniques were established to reconstruct the meniscus clinically, i.e., the allograft of the meniscus, meniscal reconstruction with the autotendon, and the meniscus scaffold. There were still a few defects in the meniscal replacement, and so the curative techniques would still be investigated. Conclusion Many efforts have been made to reconstruct the meniscus after its injury or its resection so as to prevent degeneration of the knee joint. The meniscal replacement has been employed for many years, but it has not worked so well. The establishment of an ideal replacement of the meniscus requires further studies. Therefore, reconstruction of the meniscus function is still a challenging problem to the surgeons concerned.
Objective To observe the changes of force bearing area and pressures of the rabbit tibiofemoral contact area and the biomechanical reconstruction level of joint after meniscal allograft. Methods A total of 28 Japanese rabbits were involved, weighing 3.0-3.5 kg, male or female. Of 28 rabbits, 7 were selected as meniscus donors, the remaining 21 rabbits were randomized into group A (n=7), group B (n=7), and group C (n=7). Group A underwent single knee opening and suturing, group B underwent medial meniscus excision and suturing, and group C underwent medial meniscus allograft after medial meniscus excision and suturing. The rabbits were sacrified at 12 weeks after operation for biomechanical observation through biomechanical machine and color imaging system. The meniscus tissue specimens were harvested from groups A and C to perform histological and immunohistochemical staining. Results After operation, all rabbits in 3 groups survived to the end of experiment. There were significant differences in the force bearing area and pressures at 0-90° flexion between group B and groups A, C (P lt; 0.05) at 12 weeks, showing no significant difference between group A and group C (P gt; 0.05); and there were significant differences in the force bearing area and pressures at 120° flexion among 3 groups (P lt; 0.05). The histological observation showed that the number of cartilage cells and collagen fibers returned to normal in group C, and the immunohistochemical staining showed that transplanted meniscus of group C contained large amounts of collagen fibers consisting of collagen type I and collagen type II. After 12 weeks of operation, the collagen type I contents were 0.612 5 ± 0.059 8 in group A and 0.587 2 ± 0.063 9 in group C, showing no significant difference (t=0.765, P=0.465); the collagen type II contents were 0.772 4 ± 0.081 5 and 0.814 3 ± 0.051 7, respectively, showing no significant difference (t= —0.136, P=0.894). Conclusion The allograft of rabbit meniscus can significantly increase the force bearing area of the tibiofemoral contact area and reduce the average pressure. Therefore, biomechanically speaking, the meniscus allograft can protect the articular cartilage and reconstruct the biomechanical balance.
Objective To investigate the effects of the insulin-like growth factor 1 (IGF-1), the transforming growth factor β1(TGFβ1), and the basic fibroblast growth factor (bFGF) on proliferation and cell phenotype of the human fetal meniscal cells, and to find out the best combination and concentration of the growth factors for the meniscus tissue engineering. Methods The fetus came from the healthy woman accidental abortion and the procedure had got her approval.The human fetal meniscal fibrochondrocytes were cultured in vitro. The cell phenotype was identifiedby the collagen type Ⅱ immunohistochemistry and Aggrecan immunofluorescence. Inthe growth factor groups, the 3rd passage meniscal cells synchronized by the serum starvation method and were mixed with IGF-1 (1, 10, 50, 100 μg/L), TGF-β1 (0.1, 1.0, 5.0, 10.0, 50.0 μg/L), and bFGF (5, 10, 50, 100, 200 μg/L), respectively, and in the combination groups, the combinations of bFGF and TGF-β1, bFGF and IGF-1, TGF-β1 and IGF-1 were established at their optimal effect concentrations. The control group was also established for comparison. The dose-response relationship was studied at 48 h and 72 h bythe MTT colorimetric method. Results The 3rd passage meniscalcells could express collagen type Ⅱ and Aggrecan before and after the addition of the three growth factors. The proliferating effects of the growth factors (IGF-1 50 μg/L，TGF-β1 5 μg/L，bFGF 50 μg/L) on the 3rd passage cells at 48 h and 72 h were significantly better in the growth factor groups than in the control group (Plt;0.05)，and the combination groups of bFGF 50 μg/L and IGF-1 50 μg/L, IGF-1 50 μg/L and TGF-β1 5 μg/L showed a significantly higher proliferatingeffect than that in the single growth factor group (Plt;0.05). bFGF 50 μg/L and TGF-β1 5 μg/L had no synergetic effect (Pgt;0.05). Conclusion IGF-1, TGF-β1 and bFGF can promote the proliferation of the human fetal meniscal cells, respectively, and the combinations of bFGF and IGF-1, IGF-1 and TGF-β1 at their optimal concentrations can have better proliferating effects than the single growth factor. They can be used for the in vitro amplification of the meniscal seed cells.
Objective To investigate the result of the arthroscopicrepair of the meniscus tears with the absorbable sutures. Methods From June 1998 to May2003，the meniscus tears in 110 patients (78 males, 32 females; aged 1466 years, averaged 27.5 years) were repaired with absorbable sutures under an arthroscope. In the patients, there were 93 vertical split injuries, 12 transverse split injuries, and 5 hidden split injuries. There were 78 tears in the lateral margin of the meniscus, 23 tears in the anterior angle of the meniscus, and 9 tears in the posterior angle of the meniscus. Ninetyone patients had 2 sutures, 13 patients had 4 sutures, 4 patients had 6 sutures, and 2 patients had 8 sutures. The rehabilitation program was performed in all the patients postoperatively, and the clinical outcome was observed. The Lysholm score was 57±12 preoperatively. Results Thefollow-up for an average of 26 months (range,12-67 months) showed that 3 patients had a light pain on exertion in the surgically-treated knee;1 patientunderwent an operation again for recurrence of the symptoms due to a failure in the healing of the meniscus tear, so a second arthroscopic operation was performed; and the other patients had a satisfactory result with an excellent knee function. The Lysholm score was 92±7 after operation. Conclusion The arthroscopic repair of the meniscustears has advantages of safety and reliability in the suturing and easier to perform. The repaired meniscus can play much better physiological and biomechanical functions, and will not limit the normal movement of the meniscus during the knee flexion after the sutures are absorbed.
Objective To elucidate the latest research progress and application of tissue engineered meniscus. Methods The literature concerning the advance in tissue engineered meniscus was extensively reviewed, then closely-related issues including seed cells, scaffolds, and bioreactors were analyzed. Results With more and more attention being paid to meniscus tissue engineering, different approaches and strategies for seed cells, scaffolds, and bioreactors have contributed to the generation of meniscal constructs, which are capable of restoring meniscal lesions to some extent, but translating successes in basic science research to clinical application is still limited. Conclusion More research for the optimal combination of the appropriate cell source, the scaffold type, and the proper physical and chemical factors for the stimulation of cells differentiation into tissue with optimal phenotypes in tissue engineered meniscus is still in needed, but the overall future looks promising.
Objective To investigate the effectiveness of meniscal allograft in treatment of discoid meniscus tear. Methods Between May 2005 and September 2009, 7 cases of discoid meniscus tear were treated with meniscal allograft. There were 2 males and 5 females with an average age of 22.6 years (range, 18-33 years). The locations were the left knee in 5cases and the right knee in 2 cases. The causes were sport trauma in 4 cases, impact injury in 2 cases, and no apparent reason in 1 case. Of them, 7 cases had joint tenderness gap, 2 cases had positive results in floating patella test, 7 cases had positive results in McMurray test, and 6 cases had positive results in squatting test. The range of knee motion was 0-60°. The disease duration ranged from 3 months to 17 years (median, 26 months). Results The number of the pins was 9-13 (mean, 11). The operative time ranged from 1.5 to 2.7 hours (mean, 1.7 hours). The postoperative fever time ranged from 31 to 57 hours (mean, 46.4 hours). Incisions healed by first intention in 6 cases; infection occurred in 1 case after operation and was cured after 18 days of local irrigation with antibiotic sal ine. Seven patients were followed up 21.6 months on average (range, 12-53 months). The range of knee motion was 0-125°. All patients had the negative results of floating patella test, McMurray test, and squatting test. MRI showed that there was a good heal ing between the transplanted meniscus and the surrounding synovium. The Japanese Orthopaedic Association (JOA) score was 80.71 ± 4.82 at 6 months after operation, showing significant difference (t=10.11, P=0.00) when compared with the score (41.71 ± 8.07) before operation. Conclusion Meniscal allograft in treatment of discoid meniscus tear is a rel iable and effective method, which can ease knee pain.
Objective To investigate the clinical application of periosteal autograft in repair of cartilage defect caused by osteoarthritis of knee. Methods From 1996 to 1999, 36 knees of cartilage defect of knee joint in 28 cases were treated. In the operation, the cracked degenerative cartilage was removed before free periosteum from tibia was transplanted to repair the defect, and the meniscuses in 8 knees of the 36 knees were reconstructed. After operation, early continuous passive movement was adopted for 4 weeks, and 8 knees with reconstruction ofthe meniscus were immobilized by plaster splint for 7 days after operation and before passive movement. All of the cases were followed up for 1 to 4 years before clinical evaluation in symptoms, signs and radiological findings. Results The general satisfactory rate was 86.1%, in which the function was excellent in 22 knees and good in 9 knees. Conclusion The periosteal autograft is a good choice for repairing cartilage defect due to osteoarthritis, with a satisfactory outcomein the short term.
ObjectiveTo investigate the medium-term effectiveness of both side stereo suture for meniscus bucket handle tear under arthroscopy. MethodsBetween January 2009 and December 2012, 38 patients with combined injury of meniscus bucket handle tear underwent arthroscope surgery by the method of both side stereo suture. There were 26 males and 12 females with an average age of 32 years (range, 19-42 years). The injury causes included sports injury in 21 cases, traffic accident injury in 11 cases, and other trauma in 6 cases. The left knee was involved in 15 cases and the right knee in 23 cases. The interval between injury and operation was 2 days to 6 months (mean, 2.5 months). MRI examination showed meniscus injury at grade Ⅲ, including 22 cases of internal injury and 16 cases of lateral injury. The Barrett standard, Lysholm score of knee joint, and joint mobility were used to assess the function recovery of the knee joint. ResultsAll incisions healed primarily with no complication. All cases were followed up 24.5 months on average (range, 18-36 months). Based on the Barrett standard, meniscus bucket handle tear was successfully repaired in all cases. The Lysholm scores and range of motion of the knee at 6 months, 12 months, and last follow-up were significantly better than preoperative ones (P<0.05). ConclusionThe both side stereo suture of meniscus bucket handle tear under arthroscopy has an excellent medium-term effectiveness, with the advantages of firm suture and high healing rate.