ObjectiveTo review the bioactive strategies that enhance tendon graft healing after anterior cruciate ligament reconstruction (ACLR), and to provide insights for improving the therapeutic outcomes of ACLR. Methods The domestic and foreign literature related to the bioactive strategies for promoting the healing of tendon grafts after ACLR was extensively reviewed and summarized. ResultsAt present, there are several kinds of bioactive materials related to tendon graft healing after ACLR: growth factors, cells, biodegradable implants/tissue derivatives. By constructing a complex interface simulating the matrix, environment, and regulatory factors required for the growth of native anterior cruciate ligament (ACL), the growth of transplanted tendons is regulated at different levels, thus promoting the healing of tendon grafts. Although the effectiveness of ACLR has been significantly improved in most studies, most of them are still limited to the early stage of animal experiments, and there is still a long way to go from the real clinical promotion. In addition, limited by the current preparation technology, the bionics of the interface still stays at the micron and millimeter level, and tends to be morphological bionics, and the research on the signal mechanism pathway is still insufficient.ConclusionWith the further study of ACL anatomy, development, and the improvement of preparation technology, the research of bioactive strategies to promote the healing of tendon grafts after ACLR is expected to be further promoted.
ObjectiveTo investigate the safety and effectiveness of anatomical approach osteoligaments repair technique in treatment of pronation ankle fractures.MethodsThe clinical data of 53 patients with pronation ankle fractures between April 2015 and October 2016, who were treated with anatomical approach osteoligaments repair technique applied for fracture reduction and internal fixation, were analysed retrospectively. There were 35 males and 18 females with an average age of 33.1 years (range, 18-60 years). The cause of injury included traffic accidents in 27 cases, tumbling in 5 cases, fall from height in 4 cases, twisted injury in 6 cases, sports injuries in 4 cases, and bruises in 7 cases. According to Lauge-Hansen classification, there were 44 cases of pronation external rotation stage Ⅳ and 9 cases of pronation abduction stage Ⅲ. The interval between injury and operation was 4-10 days (mean, 7 days). Postoperative pain and function of ankles were assessed by American Orthopedic Foot and Ankle Score (AOFAS) and visual analogue pain scale (VAS) score. The medial clear space (MCS), tibiofibular clear space (TFCS), distal fibular tip to lateral process of talus (DFTL), the anterior and posterior tibiofibular syndesmosis distance, and the lateral malleolus twist angle were measured by X-ray films and CT of bilateral ankle joints.ResultsThe tourniquet application time was 55-90 minutes (mean, 72.5 minutes); the frequency of fluoroscopy was 5-13 times (mean, 8.9 times). All incisions healed by first intention and no infection, deep vein thrombosis occurred after operation. All patients were followed up 28-48 months (mean, 36 months). There was no significant difference in postoperative MCS, TFCS, DFTL, the anterior and posterior tibiofibular syndesmosis distance, and the lateral malleolus twist angle between bilateral ankle joints (P>0.05). At last follow-up, no ankle instability occurred and the degenerative changes of ankle joints (Kellgren-Lawrence grading Ⅱ) occurred in 5 cases. The average AOFAS score of the ankle joint was 90.84 (range, 85-95); mean VAS score was 1.23 (range, 0-5). The average dorsiflexion and plantar flexion of ankle joints was 20.24° (range, 15-25°) and 42.56° (range, 30-50°), respectively.ConclusionAnatomical approach osteoligaments repair technique in treatment of pronation ankle fractures can expose the talocrural joint and lower tibiofibular syndesmosis clearly, repair the osteoligaments injury directly, and assist the syndesmosis and talocrural joint reduction, and decline the incidence of ankle degeneration.
ObjectiveTo compare the incidence of chondral injury using Rigidfix femoral fixation device via the anteromedial approach and the tibial tunnel approach during anterior cruciate ligament (ACL) reconstruction. MethodsEighteen adult cadaver knees were divided randomly into 2 groups, 9 knees in each group. Femoral tunnel drilling and cross-pin guide insertions were performed using the Rigidfix femoral fixation device through the anteromedial approach (group A) and the tibial tunnel approach (group B). ACL reconstruction simulation was performed at 0, 10, 20, 30, 45, 60, 70, 80, and 90°in the horizontal position. The correlation between incidence of chondral injury and slope angles was analyzed, and then the incidence was compared between the 2 groups. ResultsThe correlation analysis indicated that the chondral injury incidence increased with the increasing of the slope angle (r=0.611, P=0.000; r=0.852, P=0.000). The incidence of chondral injury was 69.1% (56/81) and 48.1% (39/81) in groups A and B respectively, showing significant difference (χ2=7.356, P=0.007). The sublevel analysis showed that the chondral injury incidence of group A (36.1%, 13/36) was significantly higher than that of group B (0) at 0-30°(χ2=15.864, P=0.000), but no significant difference was found between group A (95.6%, 43/45) and group B (86.7%, 39/45) at 45-90°(P=0.267). ConclusionIt has more risk of chondral injury to use Rigidfix femoral fixation device via the anteromedial approach than the tibial tunnel approach to reconstruct ACL.
ObjectiveTo investigate the short-term effectiveness of calcaneal lateral displacement osteotomy with lateral ligament repair in the treatment of Takakura stage Ⅱ varus-type ankle arthritis. MethodsA retrospective analysis was performed on the clinical data of 13 patients with Takakura stage Ⅱ varus-type ankle arthritis treated with calcaneal lateral displacement osteotomy with lateral ligament repair between January 2016 and December 2020. There were 6 males and 7 females aged 31-65 years, with an average age of 53.6 years. The preoperative tibial-ankle surface angle (TASA) was (88.13±1.01)°, medial distal tibial angle (MDTA) was (86.36±1.49)°, tibial talar surface angle (TTSA) was (6.03±1.63)°, talar tilting angle (TTA) was (81.95±2.15)°, and tibiocalcaneal axis angle (TCAA) was (?5.74±6.81)°. The preoperative American Orthopedic Foot and Ankle Society (AOFAS) score was 56.3±7.1 and the pain visual analogue scale (VAS) score was 3.7±0.5. AOFAS scores, VAS scores, TTSA, TTA, and TCAA were compared between pre- and post-operatively. Results All 13 patients were followed up 14-41 months, with an average of 28.7 months. The osteotomies healed in all patients. The last follow-up revealed TTA, TTSA, and TCAA to be (88.27±1.19)°, (?0.13±1.37)°, and (2.09±5.10)° respectively, the AOFAS score was 84.3±4.2 and the VAS score was 0.7±0.5, all showing significant improvement when compared to preoperative values (P<0.05). Conclusion For patients with Takakura stage Ⅱ varus-type ankle arthritis, calcaneal lateral displacement osteotomy with lateral ligament repair can correct the lower limb force line, regain ankle stability, and achieving good short-term effectiveness.
Objective To investigate the feasibility of establishing an anterior cruciate ligament (ACL) reconstruction model using hamstring tendon autograft in cynomolgus monkeys. Methods Twelve healthy adult male cynomolgus monkeys, weighing 8-13 kg, were randomly divided into two groups (n=6). In the experimental group, the ACL reconstruction model of the right lower limb was prepared by using a single bundle of hamstring tendon, and the ACL of the right lower limb was only cut off in the control group. The survival of animals in the two groups was observed after operation. Before operation and at 3, 6, and 12 months after operation, the knee range of motion, thigh circumference, and calf circumference of the two groups were measured; the anterior tibial translation D-value (ATTD) was measured by Ligs joint ligament digital body examination instrument under the loads of 13-20 N, respectively. At the same time, the experimental group underwent MRI examination to observe the graft morphology and the signal/ noise quotient (SNQ) was caculated. Results All animals survived to the end of the experiment. In the experimental group, the knee range of motion, thigh circumference, and calf circumference decreased first and then gradually increased after operation; the above indexes were significantly lower at 3 and 6 months after operation than before operation (P<0.05), and no significant difference was found between pre-operation and 12 months after operation (P>0.05). In the control group, there was no significant change in knee range of motion after operation, showing no significant difference between pre- and post-operation (P>0.05), but the thigh circumference and calf circumference gradually significantly decreased with time (P<0.05), and the difference was significant when compared with those before operation (P<0.05). At 6 and 12 months after operation, the thigh circumference and calf circumference were significantly larger in the experimental group than in the control group (P<0.05). At 3 and 6 months after operation, the knee range of motion was significantly smaller in the experimental group than in the control group (P<0.05). Under the loading condition of 13-20 N, the ATTD in the experimental group increased first and then decreased after operation; and the ATTD significantly increased at 3, 6 months after operation when compared with the value before operation (P<0.05). But there was no significant difference between the pre-operation and 12 months after operation (P>0.05). There was no significant change in ATTD in the control group at 3, 6, and 12 months after operation (P>0.05), and which were significantly higher than those before operation (P<0.05). At each time point after operation, the ATTD was significantly smaller in the experimental group than in the control group under the same load (P<0.05). The MRI examination of the experimental group showed that the ACL boundary gradually became clear after reconstruction and was covered by the synovial membrane. The SNQ at each time point after operation was significantly higher than that before operation, but gradually decreased with time, and the differences between time points were significant (P<0.05). Conclusion The ACL reconstruction model in cynomolgus monkey with autogenous hamstring tendon transplantation was successfully established.
Objective To determine the surgical indications for posterior expansive open-door laminoplasty (EOLP) extended to the C1 level. Methods Seventeen patients undergoing C3-7 or C2-7 open-door laminoplasty were included as the case group between September 2005 and January 2010, whose spinal cord injury symptoms were not alleviated or aggravated again because of the cervical stenosis at C1-4 level, and the causes of the surgery itself were eliminated, all of these patients underwent reoperation with decompress upward to C1 level. Fifteen patients with cervical stenosis who underwent C2-7 laminoplasty and C1 laminectomy were selected as the control group. There was no significant difference in gender, age, and disease duration between 2 groups (P gt; 0.05). The pre- and post-operative cervical curvature and spinal cord compression were evaluated according to the patients’ imaging data; the pre- and post-operative neurological recovery situation was evaluated by Japanese Orthopaedic Association (JOA) 17 score and spinal cord function Frankel grade; the neurological recovery rate (according to Hirabayashi et al. method) was used to assess the postoperative neurological recovery situation. Results In the case group, 8 patients underwent primary C3-7 laminoplasty. In 3 of these patients, there was a cervical stenosis at C1, 2 level, and discontinuous cerebrospinal fluid around the spinal cord was observed; 5 of them with a compression mass which diameter was exceed 7.0 mm in the C2-4 segments. The remaining 9 patients in the case group underwent primary C2-7 laminoplasty, and the diameter of the compression mass was exceed 7.0 mm in the C2-4 segments. In all 17 patients of the case group, reoperation was performed with the decompression range extended to the C1 level, and the follow-up time was 35-61 months with an average of 45.6 months. Cervical curvature: there were 11 cases of cervical lordosis, 4 cases of straight spine, and 2 cases of cervical kyphosis before operation; but after operation, 2 cases of cervical lordosis became straight spine and 1 straight case became kyphosis. The postoperative neurological improvement was excellent in 8 cases, good in 7, and fair in 2. In the control group, all the patients had a compression mass which anteroposterior diameter was exceed 7.0 mm in the C2-4 segments before operation. The follow-up time was 30-58 months with an average of 38.7 months. Cervical curvature: there were 13 cases of cervical lordosis and 2 cases of straight spine before operation; but after operation, 1 case of cervical lordosis became straight spine. The postoperative neurological improvement was excellent in 8 cases, good in 6, and fair in 1. No significant difference was found in the JOA score at pre- and post-operation between 2 groups (P gt; 0.05); however, there were significant differences (P lt; 0.05) in the JOA score between at last follow-up and at preoperation. Conclusion The initially surgical indications which can be used as a reference for EOLP extended to C1 are as follows:① Upper cervical (C1, 2) spinal stenosis: C1 posterior arch above the lower edge part of cerebrospinal fluid around the spinal cord signal is not continuous, and the anteroposterior diameter of the spinal canal actual is less than 8.0 mm as judgment standard. ②There is a huge compression at the lower edge of C2-4 vertebrae, and the most prominent part of the diameter is exceed 7.0 mm, which can not be removed through the anterior cervical surgery, or the operation is high-risk.
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.
In the study of oral orthodontics, the dental tissue models play an important role in finite element analysis results. Currently, the commonly used alveolar bone models mainly have two kinds: the uniform and the non-uniform models. The material of the uniform model was defined with the whole alveolar bone, and each mesh element has a uniform mechanical property. While the material of the elements in non-uniform model was differently determined by the Hounsfield unit (HU) value of computed tomography (CT) images where the element was located. To investigate the effects of different alveolar bone models on the biomechanical responses of periodontal ligament (PDL), a clinical patient was chosen as the research object, his mandibular canine, PDL and two kinds of alveolar bone models were constructed, and intrusive force of 1 N and moment of 2 Nmm were exerted on the canine along its root direction, respectively, which were used to analyze the hydrostatic stress and the maximal logarithmic principal strain of PDL under different loads. Research results indicated that the mechanical responses of PDL had been affected by alveolar bone models, no matter the canine translation or rotation. Compared to the uniform model, if the alveolar bone was defined as the non-uniform model, the maximal stress and strain of PDL were decreased by 13.13% and 35.57%, respectively, when the canine translation along its root direction; while the maximal stress and strain of PDL were decreased by 19.55% and 35.64%, respectively, when the canine rotation along its root direction. The uniform alveolar bone model will induce orthodontists to choose a smaller orthodontic force. The non-uniform alveolar bone model can better reflect the differences of bone characteristics in the real alveolar bone, and more conducive to obtain accurate analysis results.
Objective To determine the change in humeral head anterosuperior migration after releasing the coracoacromial l igament in shoulders from cadavers with simulated intact or irreparable teared rotator cuff, to provide biomechanical basis for preserving the coracoacromial l igament or not during hemiarthroplasty. Methods Twelve freshfrozen cadaveric glenohumeral joints of adult preserving the scapula, upper 2/3 of the humerus, articular capsule and the coracoacromial l igament, were divided into 2 groups. The suprascapularis was preserved in group A (6 shoulders) and excised in group B (6 shoulders). Positioning the joint in a combination of 30° extension, 0° abduction and 30° external rotation, and imposing a 50 N axial compressive load to the humeral shaft, the anterosuperior displacement of the humeral head weremeasured before and after excising the coracoacromial l igament. Results In group A, the displacement of the humeral head was (5.96 ± 0.77）mm with intact coracoacromial l igament and (6.83 ± 0.84）mm after transecting the l igament. In group B, the displacement of the humeral head was (8.07 ± 2.46）mm with intact coracoacromial l igament and (9.92 ± 3.29）mm after transecting the coracoacromial l igament. So the mean increase of anterosuperior migration of the humeral head was (0.88 ± 0.34) mm (P lt; 0.01) in group A, and (1.85 ± 0.99) mm (P lt; 0.01) in group B, which was greater than the former (P lt; 0.05). Conclusion The coracoacromial l igament restrained anterosuperior translation of the humeral head, especially for patients with rotator cuff deficiency, so it should be preserved as far as possible during hemiarthroplasty.
Objective To analyze the correlation between the morphology of tibial intercondylar eminence and non-contact anterior cruciate ligament (ACL) injury, and provide a theoretical basis for the prevention and risk identification of ACL injury. Methods A retrospective analysis was conducted on the knee radiographs of 401 patients admitted to the Chengdu Second People’s Hospital between January 2017 and October 2021, including 219 males and 182 females. Non-contact rupture of ACL was observed in 180 patients and confirmed by arthroscopy or surgery, while the remained 221 patients were confirmed to have normal ACL by physical examination and MRI. The heights of medial and lateral tibial intercondylar eminence and the width of tibial intercondylar eminence of the 401 patients were measured, and the risk factors of ACL injury were analyzed. Results The height of medial tibial intercondylar eminence was lower and the width of tibial intercondylar eminence was smaller in male patients with ACL fracture than those in the male control group with statistical significance (P<0.05). Logistic regression analysis showed that a narrow width of tibial intercondylar eminence was a risk factor of ACL injury in males (P<0.05). The receiver operating characteristic (ROC) curve showed that the diagnostic threshold was 11.40 mm, the area under the curve (AUC) was 0.851 [95% confidence interval (CI) (0.797, 0.896)], the sensitivity was 72.81%, and the specificity was 84.76%. The height of medial tibial intercondylar eminence was lower and the width of tibial intercondylar eminence was smaller in female patients than those in the female control group with statistical significance (P<0.05). Logistic regression analysis showed that both a low height of medial tibial intercondylar eminence and a narrow width of tibial intercondylar eminence were risk factors of ACL injury in females (P<0.05). For the width of medial tibial intercondylar eminence, the ROC curve showed that the diagnostic threshold was 8.30 mm, and the AUC was 0.684 [95%CI (0.611, 0.751)], the sensitivity and specificity were 63.64% and 72.41%, respectively; for the height of medial tibial intercondylar eminence, the diagnostic threshold was 11.30 mm, and the AUC was 0.699 [95%CI (0.627, 0.756)], the sensitivity was 89.39%, and the specificity was 47.41%. Conclusions The reduced width of tibial intercondylar eminence is a risk factor and effective predictor of non-contact ACL injury in males. Both the reduced height of the medial tibial intercondylar eminence and the reduced width of tibial intercondylar eminence are risk factors and may be predictors for non-contact ACL injury in females.