Objective To explore the biomechanic effects of multi ple freeze-thaw on human allograft tendons. Methods Thirty tendons (24 flexor digitorum superficial is tendons and 6 flexor poll icis longus tendons) were harvested from 3 fresh cadaver donors and were divided into 6 groups randomly (fresh group; 1 cycle, 2 cycle, 3 cycle, 5 cycle, and 10 cycle freeze-thaw groups). There was 4 flexor digitorum superficial is tendons and 1 flexor poll icis longus tendon in each group. The structural and mechanical properties as well as viscoelastic change were estimated. Results The results of the structural and mechanical properties in 1 cycle, 2 cycle, and 3 cycle freeze-thaw groups were similar to that of the fresh group (P gt;0.05). The tendons in 5 cycle and 10 cycle freeze-thaw groups showed a significantly lower ultimate load and maximum stress when compared with those of fresh group (P lt; 0.05), but there was no significant difference in maximum tensile or maximum strain (P gt; 0.05). Moreover, the tendons in 5 cycle and 10 cycle freeze-thaw groups had a significant increase in viscoelastic properties when compared with fresh group (P lt; 0.05). Conclusion In the cryopreservation of tendon allografts, the cycle of freeze-thaw should not exceed 3 times. Multiple cycle freeze-thaw will weaken the biomechanical properties of tendon allografts, which make grafts easier to fatigue or even rupture.
Objective To investigate the outcomes of arthroscopic reduction and internal fixation of tibial eminence avulsion fracture using absorbable double suture anchors. Methods Between February 2007 and August 2009, 18 patients with tibial eminence avulsion fracture were treated with arthroscopic reduction and fixation using absorbable doublensuture anchors. There were 12 males and 6 females with an average age of 30.6 years (range, 17-48 years). The disease causes were traffic accident injury in 4 cases, sport injury in 8 cases, and fall ing from height injury in 6 cases; the locations were left side in 7 cases and right side in 11 cases. The results of the anterior drawer test and Lachman test were positive. According to Meyers-McKeever classification, 10 cases were rated as type II, 7 as type III, and 1 as type IV fractures. The time from injury to treatment was 6-20 days (mean, 10.2 days). Results Incision healed primarily. All the patients were followed up 29.1 months (range, 13-43 months). The X-ray films showed good reduction of fracture immediately after operation and fracture heal ing at 3 months. At the last follow-up, the range of motion of knee was 0-130°. The results of Lachman test and anterior drawer test were negative in 18 cases and 16 cases, repectively; and the results of anterior drawer test were weakly positive in 2 cases. The mean Lysholm score was significantly improved from 53.9 ± 6.7 preoperatively to 91.6 ± 4.2 postoperatively (t=22.100, P=0.000). The Inter national knee Documentation Commitee (IKDC) 2000 subject score improved from 58.1 ± 3.7 preoperatively to 92.8 ± 5.9 postoperatively (t=20.700, P=0.000). Conclusion Arthroscopic treatment using absorbable double suture anchors for tibial eminence avulsion fracture can provide satisfactory reduction, stable fixation, and good heal ing of the avulsed fragment, which is a minimally-invasive, simple, and effective treatment for patients with tibial eminence avulsion fracture.
Objective To explore the diagnosis and treatment of anterior cruciate l igament (ACL) cysts of the knees. Methods The cl inical data were retrospectively analysed from 13 patients with ACL cysts between December 2000 and August 2007. The patients included 7 males and 6 females with an average age of 46.3 years (range, 32-55 years). The locationswere the left knee in 6 cases and the right knee in 7 cases. Seven cases had an obvious history of trauma, 4 cases had a history of chronic injury, and 2 cases had no obvious incentive factor. The disease duration was from 6 to 29 months (mean, 20 months). Anterior drawer test was positive in 1 case, pivot shift test was positive in 1 case, and McMurray test was positive in 3 cases. Six cases were preoperatively diagnosed by MRI. The cysts located near the tibial insertion in 6 cases, between the ACL and the posterior cruciate l igament in 3 cases, and near the femoral attachment in 4 cases. All cysts were arthroscopically resected and had the pathohistological examination. Results The pathohistological examination showed mucoid degeneration of collagen and connective tissues, and the diagnosis result was ACL cyst. All incisions healed by first intention, and no compl ication occurred. Thirteen patients were followed up 2 to 5 years (mean, 2 years and 6 months). The symptoms of arthralgia, swell ing, and interlocking of the affected knees disappeared. At 24 months postoperatively, the anterior drawer test was positive in 1 case, the pivot shift test was positive in 1 case, and McMurray test was positive in 4 cases. There was no recurrence during the follow-up. There were significant differences in the range of motion and Lysholm score between pre- and post-operation (P lt; 0.01). Conclusion ACL cysts may be indicated by simple knee pain, especially when accompanied by l imitation of joint motion without imaging evidence of osteoarthritis. The MRI finding is very important in the diagnosis of ACL cysts, and arthroscopic resection and debridement is the first choice in the treatment of ACL cysts.
Objective To compare the effectiveness between arthroscopic double-bundle and single-bundle anterior cruciate l igament (ACL) reconstruction with deep-frozen allografts. Methods Between January 2008 and January 2009, 105 patients undergoing arthroscopic ACL reconstruction with deep-frozen allografts were selected and randomly divided intosingle-bundle (n=59) or double-bundle (n=46) groups. Patients were evaluated preoperatively and postoperatively 6, 12, and 24 months. Of the patients, 93 (51 in the single-bundle group and 42 in the double-bundle group) were available for full evaluation. There was no significant difference in gender, age, height, weight, disease duration, compl ication, the International Knee Documentation Committee (IKDC) score, and Lysholm score between 2 groups (P gt; 0.05). The anterior drawer test and the Lachman test for all were rated as + in 2 groups, and the pivot shift test were rated as ++ before operation. Results All wounds healed by first intention, and no related compl ication such as fracture, infection, or deep venous thrombosis was observed. There was no significant difference in the IKDC score, Lysholm score, anterior drawer test, pivot shift test, and Lachman test between 2 groups at 6-month and 12-month follow-up (P gt; 0.05). The IKDC score, Lysholm score, pivot shift test, Lachman test, and the side-to-side difference measured by KT-1000 arthrometer in the double-bundle group were significantly better than those in single-bundle group at 24-month follow-up (P lt; 0.05). Conclusion The double-bundle ACL reconstruction with deep-frozen allografts has better effectiveness than the single-bundle ACL reconstruction.
Objective To compare the effectiveness of anatomical single-bundle (ASB) and over-the-top singlebundle (OSB) reconstruction of the anterior cruciate l igament (ACL). Methods Between January 2008 and June 2008, 64 patients with ACL injury underwent arthroscopic ACL reconstruction. ASB ACL reconstruction was performed in 28 cases (ASB group) and OSB ACL reconstruction in 36 cases (OSB group). There was no significant difference in gender, age, diseaseduration, International Knee Documentation Committee (IKDC) score, Lysholm score, and side-to-side difference between 2 groups (P gt; 0.05). Results All incisions healed by first intention; no infection or other compl ications occurred. All cases were followed up 20-24 months (mean, 21.5 months). There were significant differences in the IKDC score, Lysholm score, and the side-to-side difference between last follow-up and preoperation in 2 groups (P lt; 0.05), but there was no significant difference between 2 groups at last follow-up (P gt; 0.05). Significant differences were found in negative rate of the pivot shift test between last follow-up and preoperation in ASB group and between 2 groups at last follow-up (P lt; 0.05), but there was no significant difference between last follow-up and preoperation in OSB group (P gt; 0.05). Conclusion The effectiveness of arthroscopic ASB ACL reconstruction is better than that of arthroscopic OSB ACL reconstruction, especially in controll ing rotational stabil ity.
Objective To investigate the effectiveness of percutaneous reduction by leverage and fixation using nonabsorbable suture with neckwear knot loop l igature to treat tibial intercondylar eminence avulsion fractures under the arthroscope. Methods Between February 2003 and December 2008, 28 patients with tibial intercondylar eminence avulsion fractures were treated, including 16 left knees and 12 right knees. There were 15 males and 13 females with an average age of19.5 years (range, 14-45 years). The injury causes included traffic accident injury in 11 cases, sport injury in 10 cases, and sprain injury in 7 cases. Based on Meyers-McKeever classification, there were 18 cases of type III and 10 cases of type IV. The X-ray films showed the tibial intercondylar eminence displaced fracture. The mean time between trauma and operation was 7 days (range, 4-12 days). All patients were treated surgically with an arthroscopically assisted reduction by leverage and fixation using 5-0 Ethibond suture with neckwear knot loop l igature. Results All incisions healed by first intention without infection or injuries of nerves and vessels. Twenty-eight patients were followed up 26 months on average (range, 12-66 months). The X-ray films showed fracture heal ing within 9-13 weeks (mean, 11 weeks). At last follow-up, all patients were able to return to their pre-injury activity and daily l ife. The knee joint was stable with no l imp or impingement of intercondylar fossa. The knee joint range of motion was 0-130°. The results of Lachman and anterior drawer tests were negative in all patients. At last follow-up, the Lysholm score was 93.5 ± 2.5, showing significant difference when compared with the preoperative one (29.0±2.2, t=53.000, P=0.000). Conclusion Percutaneous reduction by leverage and fixation using nonabsorbable suture with neckwear knot loop l igature is minimally invasive and satisfied reduction and fixation in treating the tibial intercondylar eminence avulsion fracture under the arthroscope, so it is benefit for early functional exercises, and can achieve excellent results.
Objective To investigate the surgical technique and short-term effectiveness of anterior cruciate l igament (ACL) reconstruction with LARS artificial l igament. Methods Between November 2008 and April 2010, eighty patients withACL injury were treated with LARS artificial l igament under arthroscope and successfully followed up. There were 51 males and 29 females, aged from 17 to 43 years with an average of 29.2 years. The injuries were caused by sport in 63 cases, traffic accident in 14 cases, and bruise in 3 cases. There were 43 left knees and 37 right knees. The disease duration ranged from 10 days to 11 months. The anterior drawer test, Lachman test, and pivot shift test for all cases were rated as positive. The preoperative Lysholm score was 55.4 ± 5.7, Irgang score was 48.3 ± 6.2, and Larson score was 54.8 ± 7.4; and the International Knee Documentation Committee (IKDC) score was lower than normal level in all cases. Obl ique coronal MRI showed ACL injury in all cases. Residual ACL and synovium were preserved during surgery. Results All incisions healed by first intention without compl ication of infection or deep venous thrombosis. All patients were followed up 7 to 24 months with an average of 16.8 months. There were 3 cases of screws exposure toward femoral cortical bone, 2 cases of loosening tibial screw, and 1 case of knee extension l imitation, and they were cured after symptomatic treatment. No LARS artificial l igament rupture and joint fibrosis occurred during followup. At last follow-up, the results of anterior drawer test, Lachman test, and pivot shift test were positive in 2, 3, and 3 patients,respectively. There were significant differences in Lysholm, Irgang, and Larson scores of affected knees between preoperation and 6 weeks postoperatively, last follow-up, respectively (P lt; 0.05). The normal rate of IKDC score were 43.75% (35/80) and 97.50% (78/80) at 6 weeks postoperatively and last follow-up, respectively. Conclusion The viscoelastic properties of LARS artificial l igament is different from that of biological materials. The graft should be fixed at a relatively extension position to avoid knee extension l imitation and sl ight loosening of graft tension is permitted at flexion position. Good cl inical result could be achieved if the technique is well appl ied.
Objective To explore the best flexion angle of the transplantation tendon for fixing joint in simultaneously reconstructing of the anterior cruciate l igament (ACL) and posterior cruciate l igament (PCL) using semitendinosus tendon as autologous graft. Methods Twenty-four clean level New Zealand White rabbits [(aged 6-8 months, male or female, and weighing (2.5 ± 0.2) kg] were selected and divided randomly into 3 groups (n=8) according to fixation angle of the reconstructed l igaments. The bilateral semitendinosus tendons of hind legs were used to reconstruct the PCL and ACL of right hind leg, and the reconstructed l igaments were fixed at knee flexion angles of 90° (group A), 60° (group B), and 30° (group A). The rabbit general situation was observed after operation, and the specimens of the knee joints (including 10 cmdistal end and 10 cm proximal end) were harvested for testing extension and flexion, displacement, and internal and external rotation at 3 months after operation. Results All the rabbits survived to the end of experiment. There was no significant difference in maximal displacements of ACL and PCL among 3 groups (P gt; 0.05). The anterior and posterior displacements of shift in 3 groups were less than 1 mm, suggesting good stabil ity. The anterior displacement and the posterior displacement at 30° flexion and 90° flexion in group A were significantly larger than those in group C (P lt; 0.05). There were significant differences in internal rotation angle and external rotation angle between group A and group C (P lt; 0.05), and there was no significant difference among other groups (P gt; 0.05). Conclusion When simultaneously reconstructing ACL and PCL, the knee flexion angle of 60° for fixing the reconstructed l igaments can achieve the best effect.
Objective To review the methods and progress of arthroscopic reconstruction of anterior cruciate l igament (ACL) with the remnant preservation technique. Methods Recent l iterature about arthroscopic reconstruction of ACL with the remnant preservation technique was reviewed and analyzed. Results The preserved ACL after injuries could be single-bundle or remnant. The preserved remnant provided synovium for the reconstructed ACL, and it could accelerate revascularization of the graft, and it was benefit for the proprioception too, and certain kinds of remnant could contribute to the stabil ity of the joint. The preserved remnant could prevent the washing-effect of the joint fluid, then prevent the enlargement of the tibial tunnel. Cyclops or impingement may occurred in remnant preservation technique. Conclusion Remnant preservation in ACL reconstruction can provide good cl inical result. But remnant preservation is a skill demanded technique. There should be more research and cl inical trials about remnant preservation in ACL reconstruction about its necessity and advantage, also disadvantage.
Objective To investigate whether anterior cruciate l igament (ACL) reconstruction with the remnants and the remaining bundle preservation is beneficial for the revascularization of the graft or not. Methods Animal models of the ACL reconstruction in 18 healthy New Zealand White rabbits (2-3 months old) were made using about 2.5 cm long extensordigitorum longus tendon and randomly divided into three groups (n=6): remnants debridement group (group A), remnantspreservation group (group B) and remaining bundle preservation group (group C). The histological examination was made after 2, 4 and 8 weeks of operation. The intravascular injection of ink was used to observe the revascularization of the graft. The specimens were stained with HE method to observe the histological changes of the graft. Results All the animals were in good condition and had good knee functions in the observation period. There was no new vessel in groups A and B at 2 and 4 weeks postoperatively. And new vessels were observed in the synovium of the graft in group C. The areas of the vessels in group C were (505 ± 27) pixels at 2 weeks and (624 ± 23) pixels at 4 weeks. At 8 weeks postoperatively new vessels were observed in all the three groups. The new vessel areas of groups A, B and C were (674 ± 65), (836 ± 76) and (1 219 ± 146) pixels, respectively. The vessel areas of group C were significantly bigger than those of groups A and B (P lt; 0.05). The vessel area of group B was significantly bigger than that of group A (P lt; 0.05). The fibroblast amount in group B was significantly more than that in group A at 2 and 4 weeks postoperatively (P lt; 0.05). But there was no significant difference between them at 8 weeks postoperatively (P gt; 0.05). The fibroblast amount of group C was significantly more than that of group A (P lt; 0.05) at each observation time postoperatively. At 2 and 4 weeks postoperatively, the fibroblast amount of group C was significantly more than that of group B (P lt; 0.05), but there was no significant difference between them at 8 weeks postoperatively (P gt; 0.05). Conclusion ACL reconstruction with remnants and remaining bundle preservation is beneficial for the early revascularization and fibroblasts growing of the graft. So the course of necrosis, regeneration and remodel ing of the graft is shortened.