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 evaluate the feasibility and effectiveness of percutaneous cannulated screw fixation for the treatment of Day type Ⅱ pelvic crescent fracture.MethodsThe clinical data of 14 patients with Day type Ⅱ pelvic crescent fractures underwent closed reduction and percutaneous cannulated screw fixation between January 2009 and July 2016 were retrospectively analysed. There were 9 males and 5 females, aged 17-65 years (mean, 38 years). The causes of injury included traffic accident in 8 cases, falling from height in 3 cases, bruise injury in 3 cases; all were closed fractures. According to Tile classification, there were 8 cases of type B, 6 cases of type C. There were 13 cases combined with fracture of the anterior pelvic ring, including 8 cases of superior and inferior ramus of pubis fracture, 1 case of superior ramus of pubis fracture with symphysis separation, and 4 cases of symphysis separation. The interval of injury and admission was 1- 72 hours (mean, 16 hours), and the interval of injury and operation was 3-8 days (mean, 5 days). After operation, the reduction of fracture was evaluated by the Matta evaluation criteria, the clinical function was assessed by Majeed function assessment.ResultsThe operation time was 35-95 minutes (mean, 55 minutes), cumulative C-arm fluoroscopy time was 3-8 minutes (mean, 5 minutes), no iatrogenic vascular injury and pelvic organ damage occurred. Postoperative X-ray films at 2 days indicated that 2 cases of vertical shift and 2 cases of mild rotation were not completely corrected. Postoperative CT examination at 3 days indicated that 2 pubic joint screws broke through the obturator bone cortex. None of the pubic ramus screws entered into the acetabulum, but a screw of superior pubic branch broke through the posterior cortical of superior pubic branch, a screw of posterior ilium column broke through the medial bone cortex of the ilium, and no clinical symptom was observed. One patient suffered from wound infection in the pubic symphysis, then healed after 2 weeks of wound drainage, the other wounds healed by first intention. According to Matta criterion for fracture reduction, the results were excellent in 9 cases, good in 4 cases, and fair in 1 case with an excellent and good rate of 92.9%. All patients were followed up 8-24 months (mean, 14 months). All fractures healed at 4 months and restored to the normal walking at 6 months after operation, 3 patients suffered from slight pain in the sacroiliac joints and slight claudication when they were tired or walked for a long time and unnecessary for special treatment. One patient felt pain in the back of the iliac spine when he was lying down. During the follow-up, no screw loosening or other internal fixation failure occurred. At last follow-up, according to Majeed functional evaluation criteria, the results were excellent in 7 cases, good in 5 cases, and fair in 2 cases with an excellent and good rate of 85.7%.ConclusionThe percutaneous cannulated screw fixation is a safe treatment for Day type Ⅱ pelvic crescent fracture, which has a reliable fixation and good effectiveness.
ObjectiveTo investigate and analyze the effectiveness of internal fixation with the two different cannulated screw implanting methods of rhomboid and inverted triangle in the treatment of femoral neck fracture in young adults.MethodsThe clinical data of 38 young adults with femoral neck fracture who met the selection criteria between January 2018 and August 2019 were retrospectively analyzed. According to the different methods of cannulated screw implanting, the patients were divided into two groups, 19 cases in each group. The trial group was treated with closed reduction and cannulated screw rhombic distribution internal fixation, while the control group was treated with closed reduction and cannulated screw inverted triangular distribution internal fixation. There was no significant differences in patients’ gender, age, cause of injury, Garden classification of fracture, and time from injury to operation between the two groups (P>0.05). The fracture healing time, the incidence of nonunion, femoral neck shortening, and femoral head necrosis were recorded and compared between the two groups; the effectiveness was evaluated by Harris score and visual analogue scale (VAS) score at last follow-up.ResultsThe incisions of the two groups healed by first intention. All patients were followed up 12-24 months with an average of 15.5 months. There were 1 case of fracture nonunion and 2 cases of shortening of femoral neck in the trial group; while there were 2 cases of fracture nonunion, 1 case of necrosis of femoral head, and 6 cases of femoral neck shortening in the control group; the difference in the incidence of complications (15.8% vs. 47.4%) between the two groups was significant (χ2=4.385, P=0.036). The remaining 18 cases in the trial group and 17 cases in the control group all achieved osteonal union, and the healing time was (14.8±1.6) weeks and (15.9±1.3) weeks, respectively, showing no significant difference between the two groups (t=1.265, P=0.214). At last follow-up, Harris score and VAS score of the trial group were 88.9±4.3 and 1.1±0.7, respectively, while those of the control group were 86.9±5.9 and 1.3±0.9, respectively, showing no significant difference (t=0.603, P=0.550; t=1.152, P=0.257). Hip function was evaluated in accordance with Harris score, the results were excellent in 12 cases, good in 6 cases, and fair in 1 case in the trial group, the excellent and good rate was 94.74%; the results were excellent in 10 cases, good in 7 cases, and fair in 2 cases in the control group, the excellent and good rate was 89.47%; there was no significant difference in the excellent and good rate between the two groups (χ2=0.368, P=0.544).ConclusionThe short-term effectiveness of the two kinds of cannulated screw implanting methods is clear, rhomboid fixation of 4 screws has strong stability with stress distribution, which can effectively reduce the incidence of femoral neck shortening, fracture nonunion, femoral head necrosis, and other complications.
ObjectiveTo discuss the effectiveness of arthroscopic treatment of anterior cruciate ligament (ACL) tibial eminence avulsion fracture in adolescents by using double heads compressive cannulated screw fixation.MethodsTwenty-four patients with ACL tibial eminence avulsion fractures were treated by arthroscopic reduction and internal fixation with double heads compressive cannulated screw fixation between June 2014 and June 2017. There were 15 males and 9 females with an average age of 12.3 years (range, 5-18 years). The body mass index was 19.3-26.4 kg/m2 (mean, 23.3 kg/m2). The injury causes included traffic accident injury in 10 cases, sports injury in 8 cases, and falling injury in 6 cases. According to the Meyers-McKeever classification, there were 19 cases of type Ⅱ and 5 cases of type Ⅲa. All patients’ drawer test and pivot shift test were positive. The interval between injury and operation was 3-14 days (mean, 6.2 days). During the follow-up period, the fracture healing condition of patients were determined by X-ray examination; Lysholm score, International Knee literature Committee (IKDC) score, and Tegner score were used to evaluate the knee function.ResultsPrimary healing of incision was obtained in all patients after operation. All the 24 patients were followed up 6-32 months (mean, 16.4 months). At 6 weeks after operation, 3 patients had difficulty in knee flexion. After the release of the knee joint by manipulation, the knee joint function recovered normally at 6 months after operation. At last follow-up, the X-ray films showed that all the fractures healed and no epiphyseal dysplasia, knee joint deformity, or leg length discrepancy occurred. The Lysholm score, IKDC score, and Tegner score were improved from preoperative 44.3±5.4, 43.7±4.4, and 3.0±1.3 to postoperative 93.1±4.3, 94.6±3.3, and 8.1±1.2, the differences were all significant (t=25.152, P=0.000; t=28.634, P=0.000; t=13.226, P=0.000).ConclusionThe arthroscopic reduction and internal fixation with double heads compressive cannulated screw in treatment of ACL tibial avulsion fracture (Meyers-McKeever type Ⅱ and Ⅲ) in adolescents has so many advantages, such as minimal trauma, simple operation, firm fixation, little effect on the epiphyseal plate, and has a good joint function recovery.
ObjectiveTo investigate the effectiveness of minimally invasive plate and medial supporting cannulated screw fixation via tarsal sinus approach in treatment of Sanders type Ⅱ and Ⅲ calcaneal fractures. Methods A clinical data of 46 patients with Sanders type Ⅱand Ⅲ calcaneal fractures met the selective criteria between March 2016 and March 2021 was retrospectively analyzed. The factures were fixed with minimally invasive plate and medial supporting cannulated screws via tarsal sinus approach in 20 cases (group A) and with minimally invasive plate in 26 cases (group B). There was no significant difference between groups in term of the gender, age, injury causes, fracture type and side, the time from injury to operation, and preoperative calcaneal length and width, B?hler angle, Gissane angle, and visual analogue scale (VAS) score (P>0.05). The operation time, intraoperative blood loss, hospital stay, and the interval between operation and full weight-bearing were recorded. The pain improvement of patients was evaluated by VAS scores before operation and at 48 hours after operation. The ankle joint function was evaluated by American Orthopaedic Foot and Ankle Society (AOFAS) score at 3 and 12 months after operation. Besides, the calcaneal length and width, B?hler angle, and Gissane angle were measured by X-ray films before and after operation. Furthermore, the difference (loss value) between 3, 12 months and 1 day after operation was calculated. Moreover, the fracture healing and healing time was observed. ResultsAll operations of two groups were successfully completed. The incisions healed by first intention, and no vascular/nerve injury or incision infection occurred. The operation time of group A was significantly longer than that of group B (P<0.05). There was no significant difference in the intraoperative blood loss, hospital stay, and the interval between operation and full weight-bearing (P>0.05). All patients were followed up 12-36 months (mean, 14.8 months). The VAS scores at 48 hours after operation were significantly lower than those before operation in the two groups (P<0.05); there was no significant difference in the difference of pre- and post-operative VAS score between groups (P>0.05). The AOFAS scores at 12 months after operation were significantly higher than those at 3 months after operation in the two groups (P<0.05); and there was no significant difference between groups at 3 and 12 months (P>0.05). X-ray films showed that the fractures of the two groups healed and there was no significant difference in healing time (P>0.05). There was no significant difference in calcaneal length and width and Gissane angle between groups at each time point (P>0.05), but there was significant difference in B?hler angle between groups at 12 months (P<0.05). The imaging indexes of the two groups significantly improved at each time point after operation when compared with those before operation (P<0.05). There was no significant difference between different time points after operation (P>0.05) in the imaging indexes of group A. There were significant differences in the calcaneal length, calcaneal width, and Gissane angle of group B between 12 months and 1 day, 3 months after operation (P<0.05), and there was no significant difference between 1 day and 3 months after operation (P>0.05). The differences in B?hler angle of group B between different time points after operation were significant (P<0.05). There was no significant difference between groups in the loss of all imaging indexes at 3 months after operation (P>0.05). The losses of calcaneal width, B?hler angle, and Gissane angle in group A at 12 months after operation were significantly smaller than those in group B (P<0.05), and there was no significant difference in the loss of calcaneus length between groups (P>0.05). ConclusionCompared with only minimally invasive plate fixation, the combination of minimally invasive plate and medial supporting cannulated screw fixation via tarsal sinus approach for Sanders type Ⅱ and Ⅲ calcaneal fractures has the advantages of less trauma, less incision complications, reliable fracture reduction and fixation, and good long-term stability.
Objective To design a new type of three-dimensional honeycomb guide for percutaneous cannulated screw placement in femoral neck fracture and evaluate its effectiveness. Methods The clinical data of 40 patients with femoral neck fracture who met the selection criteria between June 2019 and December 2020 were retrospectively analyzed. According to different intraoperative positioning methods, they were divided into control group (20 cases, free hand positioning screws) and study group (20 cases, new guide assisted positioning screws). There was no significant difference in gender, age, side, cause of injury, Garden classification, and time from injury to operation between the two groups (P>0.05). The operation time, fluoroscopy times, guide needle puncture times, and fracture healing time of the two groups were recorded. The hip function was evaluated by Harris score at last follow-up. At immediate after operation, the following imaging indexes were used to evaluate the accuracy of screw implantation distribution: screw spacing, screw coverage area, distance from screw to cervical cortex, parallelism between screws, and screw to cervical axial deviation. Results All operations were successfully completed, and the guide needle did not penetrate the femoral neck cortex. There was no significant difference in operation time and fluoroscopy times between the two groups (P>0.05); the guide needle puncture times in the study group was significantly less than that in the control group (t=8.209, P=0.000). Imaging detection at immediate after operation showed that the screw spacing and screw coverage area in the study group were significantly greater than those in the control group (P<0.05); the distance from screw to cervical cortex, parallelism between screws, and screw to cervical axial deviation were significantly smaller than those in the control group (P<0.05). All patients were followed up 7-25 months, with an average of 19.3 months. There was no significant difference in follow-up time between the two groups (t=?0.349, P=0.729). There were 2 cases of fracture nonunion in the control group and 1 case in the study group, and the other fractures completely healed. One case of osteonecrosis of the femoral head occurred in the control group. During the follow-up, there was no complication such as vascular and nerve injury, venous thrombosis, screw penetration, withdrawal, breakage, and refracture, etc. There was no significant difference in fracture healing time and Harris score at last follow-up between the two groups (P>0.05). ConclusionThe new three-dimensional honeycomb guide has the advantages of simple structure and convenient use. It can reduce the puncture times of the guide needle and effectively improve the accuracy distribution of cannulated screw implantation.
ObjectiveTo investigate the effectiveness of TiRobot-assisted percutaneous sacroiliac cannulated screw fixation in the treatment of posterior pelvic ring injuries with sacral variations, and to evaluate its feasibility and safety. Methods The clinical data of 7 patients with Tile type C pelvic fractures and sacral variations treated with TiRobot-assisted percutaneous sacroiliac cannulated screw fixation between January 2020 and June 2021 were retrospectively analyzed. There were 5 males and 2 females with an average age of 36 years (range, 17-56 years). The causes of injury were traffic accident in 4 cases and falling from height in 3 cases. According to Tile classification of pelvic fractures, there were 1 case of type C1.1, 1 case of type C1.2, and 5 cases of type C1.3; according to Denis classification of sacral fractures, there were 3 cases of zone Ⅰ and 4 cases of zone Ⅱ; sacral deformities included 3 cases of lumbar sacralization, 2 cases of sacral lumbarization, and 2 cases of accessory auricular surface of the sacrum. The time from injury to operation ranged from 2 to 7 days, with an average of 4.6 days. The implantation time of each screw, the fluoroscopy times of each guide pin, the quality of fracture reduction (according to Matta score), the excellent and good rate of screw position, the healing time of fracture, and the incidence of complications were recorded, and the effectiveness was evaluated by Majeed score. Results A total of 13 screws were implanted during the operation, the implantation time of each screw was 10-23 minutes, with an average of 18.2 minutes; the position of the guide pin was good, and no guide pin was adjusted, the fluoroscopy times of each guide pin were 3-7 times, with a median of 4 times. Postoperative imaging data at 3 days showed that the position of sacroiliac screw implantation was evaluated as excellent. No complication such as incision infection or vascular nerve injury occurred, and no adverse events related to robotic devices occurred. At 3 days after operation, according to Matta score, the quality of fracture reduction was excellent in 6 cases and good in 1 case, and the excellent and good rate was 100%. All the 7 patients were followed up 6-15 months, with an average of 12.4 months. Bone union was achieved in all patients, and the healing time ranged from 18 to 24 weeks, with an average of 21.2 weeks. Majeed score at last follow-up was 81-95, with an average of 91.5; 5 cases were excellent, 2 cases were good, and the excellent and good rate was 100%. ConclusionTiRobot-assisted percutaneous sacroiliac cannulated screw fixation for posterior pelvic ring injury with sacral variation is accurate, safe, minimally invasive, and intelligent, and the effectiveness is satisfactory.
Objective To investigate the clinical efficacy of computer-assisted cannulated screw internal fixation system based on error correction method for femoral neck fractures. Methods A retrospective analysis was made on the clinical data of 20 femoral neck fracture patients treated by computer-assisted cannulated screw internal fixation system based on error correction method between January 2014 and October 2015 (trial group), and 36 femoral neck fracture patients undergoing traditional manual surgery with closed reduction by cannulated screw fixation in the same period (the control group). There was no significant difference in gender, age, injury cause, side of fracture, types of fracture, and time from injury to operation between 2 groups (P>0.05). The operation time, intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion, fracture healing time, fracture healing rate, and Harris hip score were compared between 2 groups. Results All incisions healed by first intention after operation, and no complication of blood vessel and nerve injury occurred. The operation time of trial group was significantly longer than that of control group (t=2.290,P=0.026), however, the intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion of trial group were significantly less than those of control group (t=–10.650,P=0.000;t=18.320,P=0.000;t=–16.625,P=0.000). All patients were followed up 12-18 months (mean, 14.7 months). X-ray films showed that fracture healing was obtained in 2 groups, showing no significant difference in fracture healing time between 2 groups (t=0.208,P=0.836). No complication of ischemic necrosis of femoral head occurred during follow-up period. At last follow-up, the Harris hip score was 87.05±3.12 in trial group and was 86.78±2.83 in control group, showing no significant difference (t=0.333,P=0.741). Conclusion Computer-assisted cannulated screw internal fixation surgery based on error correction method for femoral neck fractures is better than traditional manual surgery in decreasing intraoperative radiation and surgical trauma during operation.
ObjectiveTo systematically review the efficacy of percutaneous cannulated screw (PCS) versus plate fixation (PF) in the treatment of ankle fractures. MethodsThe Cochrane Library (Issue 5, 2014), PubMed, EMbase, CBM, CNKI, VIP and WanFang Data were searched up to May 28th 2014, for studies concerning the efficacy of percutaneous cannulated screw versus plate fixation for ankle fractures. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the methodological quality of included studies. Then, meta-analysis was performed by using RevMan 5.1 software. Result A total of 10 studies (3 RCTs and 7 CCTs) involving 627 patients were included. The results of meta-analysis showed that:compared with the PF group, the PCS group was superior in time of the operation (RCT:MD=-6.78, 95%CI -11.95 to -1.60, P=0.01; CCT:MD=-9.76, 95%CI -13.68 to -5.84, P<0.000 01), blood loss during the operation (RCT:MD=-36.14, 95%CI -40.02 to -32.17, P<0.000 01; CCT:MD=-34.80, 95%CI -37.78 to -31.81, P<0.000 01) and the time of the fracture healing (RCT:MD=-1.16, 95%CI -1.51 to -0.81, P<0.000 01; CCT:MD=-1.55, 95%CI -2.97 to -0.13, P=0.03); However, there were no statistical differences between the two groups in complication rate (CCT:OR=0.48, 95%CI 0.08 to 2.81, P=0.41), AOFAS score excellent rate (RCT:OR=2.11, 95%CI 0.81 to 5.49, P=0.12; CCT:OR=1.58, 95%CI 0.75 to 3.30, P=0.23), and postoperative malleolus pain rate (CCT:OR=0.68, 95%CI 0.00 to 148.82, P=0.89). ConclusionCurrent evidence shows that PCS is superior to PF in shorting time of the operation, reducing blood loss during the operation, and shorting time of the fracture healing. However, the complication rate, AOFAS score excellent rate, and postoperative malleolus pain rate are similar for each operation. Due to the quality limitation of the CCTs, the conclusion are needed to be verified by more high quality RCTs in future.
ObjectiveTo explore the changes of bone and risk of micro-fracture in femoral head after removal of cannulated screws following femoral neck fracture healing under the impact force of daily stress.MethodsA total of 42 specimens of normal hip joint were collected from 21 adult fresh cadaveric pelvic specimens. Wiberg central-edge (CE) angle, bone mineral density, diameter of femoral head, neck-shaft angle, and anteversion angle of femoral neck were measured. Then, the 3 cannulated screws were implanted according to the AO recommended method and removed to simulate the complete anatomical union of femoral neck fracture. The morphology of screw canal in the femoral head was observed by CT. Finally, the specimens were immobilized vertically within the impact device in an upside-down manner, and the femoral heads were impacted vertically. Every specimen was impacted at 200, 600, and 1 980 N for 20 times with the impacting device. After impact, every specimen was scanned by CT to observe the morphology changes of screw canal in the femoral head. Micro-fractures in the femoral head could be confirmed when there was change in the morphology of screw canal, and statistical software was used to analyze the risk factors associated with micro-fractures.ResultsAfter impact at 200 and 600 N, CT showed that the morphology of screw canal of all specimens did not change significantly compared with the original. After impact at 1 980 N, there were protrusion and narrowing in the screw canal of the 22 femoral head specimens (11 pelvic specimens), showing obvious changes compared with the original screw canal, indicating that there were micro-fractures in the femoral head. The incidence of micro-fracture was 52.38% (11/21). logistic regression results showed that there was correlation between micro-fracture and bone mineral density (P= 0.039), but no correlation was found with CE angle, diameter of femoral head, neck-shaft angle, and anteversion angle (P>0.05).ConclusionThe micro-fractures in the femoral head may occur when the femoral head is impacted by daily activities after removal of cannulated screws for femoral neck fractures, and such micro-fractures are associated with decreased bone density of the femoral head.