Objective To evaluate the biomechanical property of tendons repaired with the modified Kessler suture combined with " 8” suture, and to provide evidence for the clinical application of this suture methods in repairing acute Achilles tendon rupture. Methods Forty frozen flexor digitorum longus tendons from fresh pork hind leg were randomly assigned into 4 groups, 10 specimens each group. In group A, the tendons were dissected transversely at the midpoint to forming the model of tendon with transversely cutting injury. The tendons in groups B, C, and D were dissected transversely at the midpoint, then a 2 cm segment of tendon from the incision in each side was dissected longitudinally with 1 mm internal to forming " frayed tendon” model. All the tendons were sutured with2-0 non-absorbable suture material with different suturing methods: in group A, the tendons with transversely cutting injury model with Krackow suture, and in the groups B, C, and D with Krackow suture, Kessler suture, and the modified Kessler suture combined with " 8” suture separately. All repaired tendons were fixed onto the biomechanical testing machine. The length, width, and thickness of each side and midpoint of the tendons were recorded, and the cross-sectional area was calculated. The tendons were stretched at a speed of 15 mm/minutes until failure (suture avulsion or rupture). The computer automatically recorded the maximum load, stress, strain, the failure displacement, and the stiffness. These biomechanical parameters of tendons in different groups were analyzed and compared. Results There was no significant difference in the length and cross-sectional area of each tendon among 4 groups (F=0.245, P=0.863; F=0.094, P=0.963). Two tendons in group B, 1 in group C, and 1 in group D were excluded because of tendon slipping; all tendons in group A and 8 tendons in group B failured due to suture rupture, 9 tendons in group C due to suture slipping, and 9 tendons in group D due to 3 sutures slipping from tendon tissue together. The maximum load, the maximum stress, the maximum strain, the failure displacement, and the stiffness of the tendons between groups A and B showed no significant difference (P>0.05). The maximum load, the maximum stress, and the stiffness of the tendons in group D were larger than those in both groups B and C (P<0.05), but no significant difference was found in the maximum strain and the failure displacement between groups B, C, and D (P>0.05). The maximum load, the maximum stress, the failure displacement, and the stiffness of the tendons in group B were larger than those in group C (P<0.05), but the difference of maximum strain between groups B and C was not significant (P>0.05). Conclusion The modified Kessler suture combined with " 8” suture can provide better biomechanical property of the repaired tendon compared with other suture approaches.
Objective To investigate the effectiveness of individual surgery for chronic Achilles tendon rupture. Methods A retrospective analysis was made on the clinical data of 25 patients (26 Achilles tendons) with chronic Achilles tendon rupture between September 2009 and March 2016, including 22 males and 3 females with a mean age of 38 years (range,18-59 years). The median disease duration was 12 weeks (range, 4 weeks to 12 years). The repairing method depended on the defect size, injury site, and tissue condition of the involved Achilles tendon: 9 Achilles tendons were repaired by end-to-end anastomosis, 8 by a gastrocnemius turndown flap, and 9 by auto free tendon (4 ipsilateral hamstring tendon and 5 ipsilateral 2/3 peroneus longus tendon). The American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot score, heel lifting of the affected leg, active ankle range of motion (plantar flexion and dorsiflexion), maximum calf circumference, and complications were applied to assess the effectiveness. Results Hypersensitivity occurred in 1 incision, and stage I healing was obtained in the other incisions. No complication of re-rupture, infection, nerve injury, or deep venous thrombosis occurred. All the patients were followed up 8-85 months (mean, 34 months). The AOFAS ankle-hind foot score was significantly improved to 95.81±5.34 at last follow-up from preoperative 50.54±5.52 (t=–34.844,P=0.000); the excellent and good rate was 100% (excellent in 21 cases and good in 4 cases). The active dorsiflexion of the operated side [(13.9±2.4)°] was significantly lower than that of normal side [(16.7±2.0)°] (t=–9.099,P=0.000), but the active plantar flexion showed no significant difference between affected side [(39.8± 3.2)°] and normal side [(40.6±2.6°)] (t=–1.917,P=0.068). The maximum calf circumference of the operated side [(379.4±18.8) mm] was significantly lower than that of normal side [(387.1±16.6) cm] (t=–5.053,P=0.000). The other patients could finish heel lifting of the affected leg without limitation except for 1 patient. All patients returned to normal work and activity, and 12 patients returned to normal sports. Conclusion Individual surgery depending on the defect, injury site, and tissue condition of the involved Achilles tendon can repair all kinds of chronic Achilles tendon rupture with a low rate of complications.