ObjectiveTo investigate the biomechanical properties of artificial ligament in the treatment of injuries to distal tibiofibular syndesmosis so as to provide a scientific basis for clinical application. MethodsSixteen fresh ankle specimens were harvested from 8 normal fresh-frozen cadavers. The initial tests were performed on 16 intact specimens (group A) and then the distal tibiofibular syndesmosis injury models were made (group B); the distal tibiofibular syndesmosis was fixed with artificial ligament in 8 specimens (group C) and with cannulated lag screw in the other 8 specimens (group D). The pros and cons of different fixation methods were analyzed by displacement, stress shielding effect, the strength and stiffness of ankle joints, the contact area of tibiotalar articular surface and the contact stress. ResultsUnder the physiological loading or combined with external rotation moment, the displacement of group C was significantly lower than that of groups B and D (P < 0.05), but no significant difference was found between groups A and C (P > 0.05); and there were significant differences among groups A, B, and D (P < 0.05). The rates of stress shielding in the tibia and fibula of group C were significantly lower than those of group D (t=-71.288, P=0.000;t=-97.283, P=0.000). The stress strength in tibia of group C was significantly higher than that of groups A and D (P < 0.05), but no significant difference was found between groups A and D (P > 0.05). Group C had the highest stress strength in fibula, followed by group A, group D had the lowest; differences were significant among 3 groups (P < 0.05). There was no significant difference in shear strength among groups A, C, and D (P > 0.05). The axial stiffness in tibia of group D was significantly lower than that of groups A and C (P < 0.05), but no significant difference was found between groups A and C (P > 0.05). The axial stiffness in fibula of group C was significantly higher than that of groups A and D (P < 0.05), but no significant difference was found between groups A and D (P > 0.05). Group C had the highest shear stiffness in tibia and fibula, followed by group D, group A had the lowest; differences were significant among 3 groups (P < 0.05). In groups A, C, and D, the contact area of tibiotalar articular surface gradually reduced, and the contact stress gradually increased, and differences were significant among 3 groups (P < 0.05). ConclusionFixation of distal tibiofibular syndesmosis injury with artificial ligament can better meet the physiological functions of the distal tibiofibular syndesmosis and has lower stress shielding, better stress distribution. Hopefully, it can reduce the complications of the distal tibiofibular syndesmosis injuries and become a better treatment choice.
The application of artificial ligament products in anterior cruciate ligament (ACL) surgeries has gone through a long twisty way. In the 1970s, early artificial ligament products were initially used for ACL surgeries, which showed poor clinical efficacy and eventually ended up in failure. Over the last 20 years, there has been a growing number of ACL reconstruction with new artificial ligament products, including the Leeds-KeioTM, the LARSTM (Ligament Advanced Reinfocement System), and the Trevira HochfestTM. Among these new products, the LARSTM has been more commonly applied for ACL surgeries. Although these new artificial ligament products have good mechanical properties and show significant improvement of cumulative failure and complication rate, they still have limitations.
Objective Anterior cruciate ligament (ACL) reconstruction using a new generation of artificial ligaments (NGAL) gained popularity in China owing to its good effectiveness and early functional recovery, but iatrogenic surgical failures and preconceived misconceptions have seriously affected its standardized clinical application. A specialist consensus is now developed to provide guidance and reference for orthopaedic sports medicine doctors when adopting or considering the NGAL for ACL reconstruction. Methods The consensus on the core techniques and adverse events in ACL reconstruction using the NGAL was developed by a modified Delphi method, referring exclusively to the NGAL for ACL reconstruction approved by the National Medical Products Administration (NMPA). Consensus specialists were selected from the members of the Chinese Association of Orthopaedic Surgeons (CAOS) and the Chinese Society of Sports Medicine (CSSM). The drafting team summarized the draft consensus terms based on medical evidence and organized rounds of investigation: two rounds of online questionnaire investigation and the final round of face-to-face meeting. After discussion, revision, and voting, a consensus on the draft consensus term was reached when the agreement rate exceeded 85%. The consensus terms were categorized as “strong” (agreement rate: 95.0%-100%), “moderate” (agreement rate: 90.0%-94.9%), and “basic” (agreement rate: 85.0%-89.9%). ResultsThirty-one specialists completed the questionnaire investigation. They all practiced in university teaching hospitals (Grade-A tertiary hospitals) from 16 provinces, autonomous regions, and municipalities in China. Among them, 28 were chief physicians and 3 were associate chief physicians; 22 were professors and 7 were associate professors; the average seniority in orthopedic sports medicine was 25.2 years (range, 12-40 years); the average seniority in performing ACL reconstruction procedures was 13.2 years (range, 7-23 years); in terms of the number of ACL reconstruction using the NGAL, 18 completed more than 100 cases, of which 6 had more than 300 cases; in terms of research, 28 had published more than 1 related paper in the past 5 years, of which 13 had published more than 3 related papers. Twenty-six specialists attended the face-to-face meeting and reached a consensus on 9 terms, including 8 strong terms and 1 moderate term. Conclusion ACL reconstruction using the NGAL must deploy “isometric” or “near-isometric” reconstruction and should preserve the natural ACL remnants as much as possible. Bone tunnel positioning can be performed using intraoperative radiographic measurements or the lateral femoral intercondylar ridge as reference marks. Incorrect positioning of the bone tunnel is the main reason of surgical failure, and there is a lack of consensus on handling interference screws during revision. Bone tunnel enlargement exists after reconstruction but rarely causes related symptoms. Synovitis and infection are uncommon complications. The aging effect of polyethylene terephthalate fiber on the long-term clinical outcomes is unknown and deserves attention.