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find Keyword "Screw" 10 results
  • EFFECTIVENESS AND BIOMECHANICAL ANALYSIS OF THREE FIXATION METHODS IN TREATMENT OF POSTERIOR Pilon FRACTURES

    Objective To investigate the effectiveness and biomechanical analysis of 3 fixation methods of screw anterior-posterior fixation (SAPF), screw posterior-anterior fixation (SPAF), and buttress plate fixation (BPF) in treatment of posterior Pilon fractures. Methods Fifteen fresh-frozen skeleto-ligamentous lower leg specimens were harvested to establish the models of posterior Pilon fracture, and then fracture was fixed with BPF (n=5), SAPF (n=5), and SPAF (n=5). Vertical force was loaded to internal fixation failure in a speed of 1 cm/minute with servohydraulic testing machine. The instantaneous loads of 1 mm and 2 mm steps and the failure modes were recorded. Between May 2008 and December 2011, 56 patients with posterior Pilon fracture were treated with SAPF (SAPF group) in 11 cases, or SPAF (SPAF group) in 26 cases, or BPF (BPF group) in 19 cases. There was no significant difference in age, gender, injury cause, side, disease duration, and complications among groups (P gt; 0.05). Clinical and radiographic examinations were used to assess the reduction and healing of fracture; the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the visual analogue scale (VAS) were used to evaluate the functional outcomes. Results No breaking or bending was observed in all specimens, fixation failure was caused by cancellous bone compression. The instantaneous loads of 1 mm and 2 mm steps were the largest in BPF group, larger in SPAF group, and smallest in SAPF group, showing significant differences among 3 groups (P lt; 0.05). A total of 47 cases were followed up 16-54 months (9 in SAPF group, 22 in SPAF group, and 16 in BPF group), with a mean time of 35.2 months. Fixation failure was found in 2 cases of SAPF group; the other cases obtain bony union within 3 to 4 months (mean, 3.2 months) with no fixation failure. The AOFAS score was significantly lower in SAPF group than in SPAF and BPF groups (P lt; 0.05), but no significant difference was found between SPAF and BPF groups (P gt; 0.05). The VAS score was significantly higher in SAPF group than in SPAF and BPF groups (P lt; 0.05), but no significant difference was found between SPAF and BPF groups (P gt; 0.05). Conclusion SAPF could not reach enough fixation strength for the posterior Pilon fracture; both SPAF and BPF could reach rigid fixation, and have good effectiveness. And from the biomechanical points, BPF could reach better fixation strength than screw fixations.

    Release date:2016-08-31 04:05 Export PDF Favorites Scan
  • EFFECTIVENESS COMPARISON OF TWO ARTHROSCOPIC DIFFERENT FIXATIONS FOR ANTERIOR CRUCIATE LIGAMENT TIBIAL EMINENCE AVULSION FRACTURES

    Objective To compare the effectiveness of arthroscopic screw and suture fixations in treatment of anterior cruciate ligament tibial eminence avulsion fractures. Methods Between January 2002 and January 2009, 43 patients with freshanterior cruciate ligament tibial eminence avulsion fracture were treated, which were rated as types II and III according to Meyers- McKeever-Zaricznyj classification. Fractures were fixed with either screw (screw group, n=21) or nonabsorbable suture (suture group, n=22). There was no significant difference in sex, age, disease duration, and fracture type between 2 groups (P gt; 0.05). The range of motion (ROM) and Lysholm score were compared between 2 groups, and the knee stabil ity was evaluated based on the Lachman test and KT-2000 measurement. Results The operation time was 48-60 minutes (mean, 51.6 minutes) in the screw group, and 55-68 minutes (mean, 63.2 minutes) in the suture group, showing significant difference (t=4.645, P=0.032). Incisions healed by first intention and no compl ication occurred in 2 groups. All patients were followed up (5.7 ± 0.6) years in the screw group and (5.3 ± 0.5) years in the suture group. The fracture healed completely in both groups; the heal ing time was (3.3 ± 0.6) months in the screw group and (3.2 ± 0.4) months in the suture group, showing significant difference (t=3.723, P=0.019). Between the screw group and the suture group, no significant difference was found in ROM [(128.6 ± 10.1)° vs. (130.2 ± 14.1)°, P gt; 0.05] and Lysholm score (94.6 ± 14.5 vs. 95.1 ± 17.2, P gt; 0.05). The stabil ities based on KT-2000 measurement were also similar between 2 groups at last follow-up [(0.9 ± 0.3) mm vs. (1.0 ± 0.4) mm, P gt; 0.05]. Lachman test of 2 groups were negative. Conclusion Boththe screw and nonabsorbable suture fixation techniques for anterior cruciate l igament tibial eminence avulsion fracture (type II or III) have good results in terms of functional outcome and stabil ity. However, some patients show flexion contractures of 5° or 10°.

    Release date:2016-08-31 05:44 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY OF CERVICAL PEDICLE SCREW LOCATOR SYSTEM

    Objective To develop a high-accuracy, better-safety and low-cost cervical pedicle locator system for guiding cervical pedicle screw placement. Methods Cervical pedicle screw locator system was made of stainless steel. Ten cervical specimens from voluntary donation were divided into two groups according to compatibil ity design: control group inwhich 60 screws were planted into C2-7 by free hand; and experimental group in which 60 screws were planted into C2-7 under the guidance of three-dimensional locator system. The condition of screw insertion was observed and the accuracy was evaluated by the integrity of pedicle walls. Results In the control group, 32 screws (53.33%) were placed inside the pedicles and 28 (46.67%) were outside; 9 screws (15.00%) led to nerve root injury, 5 screws (8.33%) caused vertebral artery injury and no spinal cord injury occurred; and the qual ification ratio of screw insertion was 76.67% (excellent 32, fair 14, poor 14). While in the experimental group, 54 screws (90.00%) were placed inside the pedicles and 6 (10.00%) were outside; 1 screw (1.67%) caused vertebral artery injury and no nerve root injury and spinal cord injury occurred; and the qual ification ratio of screw insertion was 98.33% (excellent 54, fair 5, poor 1). There was significant difference between the two groups (P lt; 0.05). Conclusion Cervical pedicle screw locator system has the advantages of easy manipulation, high accuracy of screw placement and low cost. With further study, it can be appl ied to the cl inical.

    Release date:2016-09-01 09:05 Export PDF Favorites Scan
  • EXPERIMENTAL STUDY OF POSTERIOR PEDICLE SCREW PLACEMENT ON ATLAS

    Objective To assess the possibility of placing the posterior pedicle screw on atlas. Methods Twenty human cadaver specimens were used to insert pedicle screws in atlas, through the posterior arch or the pedicle of C1 into the lateral mass. The screw entry point was on the posterior surface of C1 posterior arch and at the intersection of the vertical line through the center of C2 inferior articular process and the horizontal line at least 3 mm below the superior rim of the C1 lamina. The screw of 3.5 mm in diameter was placed in a direction of 10° medial angle and 5° upwardangle. After placement of C1 pedicle screw, the distance from C1 screw entry point to the mediallateral midpoint of C1 pedicle, the maximum length of screw trajectory and the actual screw trajectory angles were measured. The direction of screw penetrating through the cortical of C1 pedicle or lateral mass and the injuries to the vertebral artery and spinal cord were observed.Results Forty pedicle screws were placed on atlas, the mean distance from C1 screw entry point to the medial-lateral midpoint of C1 pedicle was (2.20±0.42)mm, the maximum length of screw trajectory averaged (30.51±1.59)mm, and the actual screw trajectory angle measured (9.7±0.67)° in a medial direction and (4.6±0.59) ° in a upward direction. Only 1 screw penetrated the upper cortical bone of the atlas pedicle because the upward angle was too large, and 8 screws were inserted so deep that the inferior cortical bone of the C1 lateral mass was penetrated. But no injuries to the vertebral artery and spinal cord wereobserved. Conclusion C1 posterior pedicle screw fixation is quite accessible and safe, but the su

    Release date:2016-09-01 09:33 Export PDF Favorites Scan
  • Surgical or Conservative Treatment for Acute Nondisplaced Scaphoid Fractures in Adults: A Systematic Review

    Objective?To determine the effectiveness and safety of surgical treatment compared to conservative treatment for adult acute nondisplaced scaphoid fractures. Methods?We searched the specialized trials registered in the Cochrane muscle group, The Cochrane Library (CCTR), MEDLINE (1966 to 2007), EMbase (1980 to 2007), PubMed (1966 to 2007), NRR, CCT, and CBMdisc (1979 to July 2007). We also handsearched some Chinese orthopedics journals. Randomized controlled trials (RCTs) of surgical treatment versus conservative treatment for adult acute nondisplaced scaphoid fractures were included. The extraction of data and the methodological assessment of included RCTs were performed by two reviewers independently. RevMan software was used to carry out meta-analysis. Results?Five RCTs including 269 patients met the inclusion criteria. Compared with conservative treatment, the time taken before returning to work or participation in sports was shorter in the surgical treatment group. Because of inadequate extraction data and heterogeneity in the included studies, the results of the time of union and grip strength were not consistent. But all the results showed favorable tendencies. No significant difference was found in wrist motion and complications between the surgical and conservative treatment groups. Conclusion?Compared with conservative treatment for adult acute nondisplaced scaphoid fractures, surgical treatment could decrease the time of returning to work or participation in sports, decrease the time of union, and improve grip strength. But it does not improve the wrist motion or decrease the complications. Because of the small sample size, this conclusion should further tested using well-designed, large scale RCTs.

    Release date:2016-09-07 02:10 Export PDF Favorites Scan
  • MANUFACTURE AND CLINICAL APPLICATION OF SCREW DIRECTOR OF CALCANEOUS SUSTENTACULUM TALI FOR TREATMENT OF INTRA-ARTICULAR CALCANEAL FRACTURES

    ObjectiveTo evaluate the clinical results of the self-manufactured screw director of the calcaneous sustentaculum tali in the surgical treatment of intra-articular calcaneal fractures. MethodsBetween May 2012 and October 2013, 40 patients (47 feet) underwent surgical treatment of intra-articular calcaneal fractures, and the clinical data were analyzed. There were 29 males and 11 females with an average age of 46 years (range, 25-68 years). According to Sanders classification, 17 feet were rated as type Ⅱ, 20 feet as type Ⅲ, and 10 feet as type IV. The average time from injury to admission was 6.02 hours (range, 1-12 hours). All the patients were treated with the screw director of the calcaneous sustentaculum tali to fix the sustentaculum tali. The intraoperative times of fluoroscopy were recorded. The Böhler angle and Gissane angle were measured at pre- and post-operation. The clinical functional outcomes were evaluated according to the Maryland foot score system. ResultsThe intraoperative times of fluoroscopy were 2-4 times (mean, 2.85 times). Radiographic examination showed 45 screws were accurately implanted into the middle of the sustentaculum tali in implanted 47 screws except 1 screw which penetrated into the anteroinferior of the sustentaculum tali and 1 screw which penetrated into the anterior of the sustentaculum tali. The accurate rate of screw implant was 95.7%. All patients were followed up for an average of 12 months (range, 8-18 months). During the follow-up, incision skin necrosis and infection occurred in 2 cases, and sural nerve injury developed in 3 cases. Bone union was achieved at an average of 12.72 weeks (range, 9-18 weeks) postoperatively. The Böhler angle was improved significantly from (6.48±3.67)° pre-operatively to (29.40±4.65)° post-operatively (t=-31.38, P=0.00). The Gissane angle was improved significantly from (99.30±5.85)° pre-operatively to (130.84±5.08)° post-operatively (t=-28.32, P=0.00). The Maryland foot score was 90.66 on average (range, 65-98) at last follow-up; the results were excellent in 41 feet, good in 3 feet, and fair in 3 feet with an excellent and good rate of 93.6%. ConclusionThe self-manufactured screw director of the calcaneous sustentaculum tali can significantly improve the accuracy of the screw implanted into the sustentaculum tali and reduce the harm of intraoperative fluoroscopy to the body.

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  • SCREW-BASED INTERMAXILLARY TRACTION COMBINED WITH OCCLUSAL SPLINT FOR TREATMENT OF PEDIATRIC MANDIBULAR CONDYLAR FRACTURE

    ObjectiveTo evaluate the effectiveness of the screw-based intermaxillary traction combined with occlusal splint in the treatment of pediatric mandibular condylar fracture. MethodsBetween June 2005 and December 2013, 35 pediatric patients with 49 mandibular condylar fractures were treated, and the clinical data were retrospectively reviewed. There were 25 boys and 10 girls, aged 3-13 years (mean, 7.3 years). The injury causes included falling (18 cases), traffic accident (14 cases), and violence (3 cases). The time between injury and treatment was 2-30 days (mean, 6.8 days). Restricted mouth opening was observed, and the maximal mouth opening was (22.74±7.22) mm except 3 patients who were too young to measure. Condylar fractures were located at the left (12 cases), at the right (9 cases), at bilateral (14 cases) based on the sites; and fractures were classified as intra-capsular (35 fractures), neck (10 fractures), and subcondylar (4 fractures) based on the fracture line. Four self-drilling titanium screws were inserted into the alveolar bone of both maxilla and mandible. After screw inserting, an occlusal splint with a fulcrum was used on the affected side and elastic band was put to perform anterior intermaxillary traction. After 1 month, the screws and splint were removed. Follow-up examinations were carried out on schedule. ResultsAll the patients were followed up from 6 months to 8 years and 10 months (median, 71 months). No screw-related complication occurred in the others except one case of screw loosening. The postoperative maximal mouth opening was (38.82±2.02)mm. Mild joint noise was found in 4 cases and opening deviation occurred in 6 cases. Radiographic results demonstrated complete condyle remodeling was achieved in 24 cases (32 fractures), and moderate remodeling in 11 cases (17 fractures) at last follow-up. ConclusionThe screw-based intermaxillary traction combined with occlusal splint might be an effective method for pediatric mandibular condylar fracture. The screw-related complications may be avoided by careful preoperative investigations.

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  • TREATMENT OF PRONATION EXTERNAL ROTATION ANKLE FRACTURE COMBINED WITH SEPARATION OF DISTAL TIBIOFIBULAR SYNDESMOSIS

    ObjectiveTo evaluate the difference between using and not using syndesmotic screw to treat pronation external rotation (PER) ankle fracture combined with separation of distal tibiofibular syndesmosis. MethodsBetween April 2011 and October 2014, 46 cases of PER ankle fracture combined with separation of distal tibiofibular syndesmosis were treated, and syndesmotic screw was used in 24 cases (fixation group) and syndesmotic screw was not used in 22 cases (non-fixation group). There was no significant difference in gender, age, weight, cause of injury, side, injury to operation time, and fracture type between 2 groups (P > 0.05). The time for full weight-bearing, fracture healing time, and complications were recorded after operation. Anteroposterior and lateral X-ray films were taken to measure the tibiofibular overlap (TBOL) and tibiofibular clear space (TBCS). Baird-Jackson score was used to evaluate functional recovery of the ankle. ResultsAll incision healed by first intention without complications. The cases were followed up 13-18 months (mean, 15.2 months) in 2 groups. The time for full weight-bearing was 8-12 weeks (median, 11 weeks) in fixation group, which was significantly later than that in non-fixation group (range, 6-10 weeks; median, 8 weeks) (Z=-5.049, P=0.000). X-ray examination showed reduction of separation of distal tibiofibular syndesmosis. All fractures healed. The fracture healing time was (13.83±1.37) weeks in fixation group, and was (13.91±1.31) weeks in non-fixation group, showing no significant difference (t=-0.191, P=0.945). No separation of distal tibiofibular syndesmosis, delayed union, nonunion, loosening, or breakage of fixation devices was observed in 2 groups. There was no significant difference in TBOL, TBCS, Baird-Jackson score and the excellent and good rate between 2 groups (P > 0.05). ConclusionIf the medial, lateral, and posterior structures of the ankle could be repaired according to injury, no significant influence on functional outcome of ankle or radiologic findings could be detected whether syndesmotic fixation is given or not in treating PER ankle fracture (exclude Maisonneuve fracture) combined with separation of distal tibiofibular syndesmosis.

    Release date:2016-10-02 04:55 Export PDF Favorites Scan
  • ISO-C3D NAVIGATION FOR PERCUTANEOUS SACROILIAC JOINT SCREW INTERNAL FIXATION FOR TREATMENT OF PELVIC POSTERIOR RING INJURIES

    ObjectiveTo investigate the advantages and effectiveness of ISO-C3D guided percutaneous sacroiliac joint screw internal fixation for treatment of pelvic posterior ring injuries by comparing with anterior opened reduction and reconstruction plate internal fixation. MethodsA retrospective analysis was made on the clinical data of 54 patients with posterior ring injury treated between June 2013 and January 2016. Of 54 patients, 33 underwent ISO-C3D guided percutaneous sacroiliac joint screws internal fixation (group A), and 21 underwent anterior opened reduction and reconstruction plate internal fixation (group B). There was no significant difference in gender, age, cause of injuries, injury to operation time, fractures type, combined injuries, and injury severity score (ISS) between 2 groups (P > 0.05). The operation time, intraoperative blood loss, length of operative incision, hospitalization time, postoperative pain degree, reduction evaluation, and functional evaluation were compared between 2 groups. ResultsGroup A was significantly better than group B in operation time, length of operative incision, and hospitalization time (P < 0.05). The intraoperative blood loss of group A (10-20 mL) was significantly less than that of group B[(524.1±160.1) mL]. All patients of the 2 groups were followed up 7 to 24 months with an average of 11.6 months. No injury of vessel or nerve occurred in group A; worse neurological symptoms of lower limbs and incision infection were observed in 2 patients of group B respectively, and the other patients achieved primary healing of incision. At 48 hours after operation, the visual analogue scale (VAS) score of group A (1.7±0.7) was significantly lower than that of group B (8.2±0.8) (t=-30.463, P=0.000). Radiological examination showed fracture reduction. According to the Matta score standard, the reduction results were excellent in 21 cases (63.6%), good in 10 cases (30.3%), and fair in 2 cases (6.1%) in group A; the reduction results were excellent in 16 cases (76.2%), good in 4 cases (19.1%), and fair in 1 case (4.7%) in group B; and there was no significant difference between 2 groups (χ2=0.961, P=0.618). Fracture or dislocation healed well in 2 groups, and the walking function was restored. According to the Majeed standard for evaluation, the results were excellent in 23 cases (69.7%), good in 9 cases (27.3%), and fair in 1 case (3.0%) in group A; the results were excellent in 14 cases (66.7%), good in 5 cases (23.8%), and fair in 2 cases (9.5%) in group B; no significant difference was shown between 2 groups (χ2=1.501, P=0.591). ConclusionCompared with anterior opened reduction and reconstruction plate internal fixation, ISO-C3D navigation percutaneous sacroiliac joint screw internal fixation is an ideal surgical method to treat pelvic posterior ring injury, with the characteristics of less trauma, less pain, precise screw implant and safety.

    Release date:2016-11-14 11:23 Export PDF Favorites Scan
  • Meta-analysis of the long-term efficacy of unilateral versus bilateral screw fixation on thoracolumbar single vertebral fracture

    ObjectiveTo evaluate the long-term effect of unilateral versus bilateral screw placement on thoracolumbar single vertebral fracture by means of meta-analysis.MethodsThe data of China National Knowledge Infrastructure, Wangfang Database, SinoMed, VIP Database for Chinese Technical Periodicals, PubMed, Elsevier Science Direct, EBSCO, Web of Science, and Springer Link were searched by computer, and the literatures related to effect comparison between unilateral and bilateral pedicle screw fixation in thoracolumbar single vertebral fracture were collected, including domestic and foreign published journal literatures and grey literatures such as academic conference reports and dissertations. The retrieval time was from their inception to August 17, 2019. After literature screening, quality evaluation, and data extraction, Stata 12.0 and RevMan 5.0 softwares were used for data analysis.ResultsA total of 12 articles were included, including 7 in English and 5 in Chinese, with a total of 848 patients (424 in the unilateral pediclescrew fixation group and 424 in the bilateral pedicle screw fixation group). The results of meta-analysis showed that: there was no significant difference in any of the main outcome indicators between the two groups, including the ratio of anterior height of fractured vertebra [mean difference (MD)= −0.16%, 95% confidence interval (CI) (−1.20%, 0.88%), P=0.76], postoperative follow-up Cobb angle [MD=−0.17°, 95%CI (−0.50, 0.15)°, P=0.29], postoperative follow-up Visual Analogue Scale score [MD=−0.06, 95%CI (−0.16, 0.04), P=0.24], postoperative follow-up Oswestry Disability Index score [MD=−0.28, 95%CI (−0.66, 0.11), P=0.15], and incidence of complications [relative risk=0.81, 95%CI (0.57, 1.15), P=0.23], but two secondary outcome indicators namely operation time [MD=−33.26 minutes, 95%CI (−51.72, −14.80) minutes, P=0.000 4] in the unilateral pedicle screw fixation group were smaller than those in the bilateral pedicle screw fixation group, whlie there were no statistically significant difference in postoperative length of hospital stay [MD=−1.59 days, 95%CI (−4.53, 1.36) days, P=0.29] and intraoperative blood loss [MD=−74.09 mL, 95%CI (−155.96, 7.77) mL, P=0.08] between the two groups.ConclusionUnilateral and bilateral screw placement of thoracolumbar single vertebral fracture has the same long-term effect, and unilateral screw placement can reduce the number of screw implantation, and shorter operation time, which is more in line with the actual clinical needs.

    Release date:2020-02-24 05:02 Export PDF Favorites Scan
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