Objective To evaluate the internal fixation effect, degradation, and biocompatibility of polylactic-co-glycolic acid/hydroxyapatite (PLGA/HA) absorbable cannulated screws in treatment of lateral femoral condyle fracture of canine so as to provide the theory basis for their further improvement and clinical application. Methods Sixteen adult male Beagles (weighing, 9-12 kg) were selected to prepare the models of bilateral lateral femoral condyle fracture; left fracture was fixed with PLGA/HA absorbable cannulated screws as experimental group and right fracture with metal screws as control group. At 2, 4, 8, and 12 weeks after operation, general observation was done and X-ray films were taken for observing fracture healing; bone mineral density was measured; the histological examination was performed; and the degradation property of absorbable cannulated screws was detected. Results All animals survived to the end of the experiment. General observations showed that no fracture displacement occurred and fracture healed at 12 weeks in 2 groups; no breakage, displacement, or loosening of screws was observed in experimental group. X-ray films results showed that the absorbable cannulated screws could not be found out by X-ray in experimental group, but metal screws could be found out in control group; fracture healed with time in 2 groups. The bone mineral density reached the peak at 8 weeks in 2 groups, and no significant difference was found between 2 groups and among different time points in the same group (P gt; 0.05). Histological examination showed that 2 groups had similar fracture healing process at different time points; no obvious inflammatory reaction was found around absorbable cannulated screws in experimental group. The degradation results of absorbable cannulated screws showed that the intrinsic viscosity and molecular weight distribution obviously decreased at 2 weeks; the number average molecular weight and the weight average molecular weight markedly decreased at 4 weeks; and the maximum shear force did not decrease obviously at 8 weeks, and then decreased significantly. Significant differences were found in all indexes among different time points in the same group (P lt; 0.05). Conclusion PLGA/HA absorbable cannulated screws and metal screws show similar fracture healing process for fixing lateral femoral condyle fracture of canine, and the absorbable canulated screws have good biocompatibility. The maximum shear force of PLGA/HA absorbable cannulated screw has no obvious decrease during 8 weeks after operation, so it can ensure full healing of fracture.
ObjectiveTo investigate the effectiveness of anatomical reconstruction of the anterior talofibular ligament by partial peroneal brevis tendon combined with double intra-fix screws.MethodsA clinical data of 46 patients with the anterior talofibular ligament rupture admitted between September 2015 and October 2019 and met the selection criteria were retrospectively analyzed. All anterior talofibular ligaments were reconstructed with partial peroneal brevis tendon and fixed with double intra-fix screws. There were 22 males and 24 females, with an average age of 28.1 years (range, 16-52 years). Forty cases had a history of ankle sprain, 1 case was injured by a heavy object, and 5 cases were suffered from falls. There were 17 cases on the left side and 29 cases on the right side. The disease duration ranged from 3 months to 10 years (median, 20.3 months). The visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, varus angle of ankle, and the difference of the anterior talar translation between healthy and affected sides (looseness, similarity, tightness) were recorded before and after operation; 23 patients were evaluated by Patient-Reported Outcomes Measurement Information System (PROMIS) score, including pain interference (PI) and physical function (PF) scores.ResultsThe operation time was 39-179 minutes, with an average of 65.8 minutes. All incisions healed by first intention. All patients were followed up 12-30 months (mean, 23 months). The VAS score, AOFAS ankle-hindfoot score, varus angle of ankle, difference of the anterior talar translation between healthy and affected sides, and PI and PF scores of PROMIS at 6 months and last follow-up significantly improved when compared with those before operation (P<0.05). There was no significant difference in VAS score, PI score of PROMIS, and AOFAS ankle-hindfoot score between at 6 months and at last follow-up (P>0.05). However, the PF score of PROMIS, the difference of the anterior talar translation between healthy and affected sides, and the varus angle of ankle were significant (P<0.05).ConclusionAnatomical reconstruction of the anterior talofibular ligament by partial peroneal brevis tendon and double intra-fix screws has the advantages of small incision, convenient tendon removal, and firm graft fixation. The postoperative patients recover quickly and the effectiveness is satisfactory.