Displacement Of Fracture Fragments Research Articles

Reconstruction of talus model with Mimics software for treatment of talar posterior process fracture through posteromedial malleolar approach

Objective To evaluate the advantages of reconstructing by mimics software before operation a three-dimensional model of talar posterior process fracture which is to be used in the treatment of talar posterior process fracture through the posteromedial malleolar approach. Methods From May 2015 to February 2019, 7 patients with talar posterior process fracture were treated at Department of Orthopaedic Trauma, Jishuitan Hospital. They were 5 men and 2 women, aged from 20 to 70 years (mean, 39 years). They underwent routine CT examination preoperatively. Their posterior process of talus was reconstructed by Mimics software based on their CT scanning data before operation to determine the size, number and displacement of fracture fragments. Their fractures of posterior process of talus were treated by open reduction and screw fixation in prone position through the posterior ankle approach. The American Orthopedic Foot & Ankle Society (AOFAS) ankle-hindfoot scoring system was used to evaluate functional recovery. Results The operation time for this group ranged from 70 min to 105 min, averaging 87.1 min. Early after operation, the wounds healed well with no injury to nerves or tendons. All patients were followed up for 4 to 24 months (average, 12 months). Follow-up by X-ray examination after 10 to 16 weeks revealed fracture union with no complications like screw breakage, nonunion, malunion or traumatic arthritis. Their AOFAS ankle-hindfoot scores at the final follow-up ranged from 80 to 98 points. Conclusion Preoperative three-dimensional reconstruction of talar posterior process fracture based on CT images using Mimics software can accurately determine the entry point and direction of screw insertion, yielding advantages of clear exposure, easy reduction and convenient screwing in the treatment of talar posterior process fracture through the posteromedial malleolar approach. Key words: Talus; Os trigonum; Fractures, bone; Materialise’s interactive medical image control system; Surgical approach

Evaluation of labial versus labio-inferior lines of osteosynthesis using 3D miniplate for fractures of anterior mandible: A finite element analysis with a pilot clinical trial

PurposeThe fractures of anterior mandible are subject to severe torsional forces due to muscles acting in opposite directions. 3D miniplate has been suggested as a good alternative by some researchers. However, finite element model (FEM) studies indicate that labio-inferior positioning of two miniplates perpendicular to each other offers better stability as compared to labial positioning. This study aims at combining the advantages of a single 3D miniplate and labio-inferior positioning of two conventional miniplates, which was assessed by finite element analysis along with a pilot clinical trial. MethodsTwo FEM models were created using CT data of a 24-year-old patient with Angle class I occlusion: control model with labial plating and study model with labio-inferior plating. The models were processed with MIMICS® (materialise, Leuven, Belgium), CATIA® (Dassault Systemes) and finite element analysis softwares. Parameters adopted for analysis were (1) displacement (mm) of fracture fragments during each screw fixation, (2) lingual splay and post fixation stability of fracture fragments with masticatory load, and (3) stress distribution (MPa) across fracture fragments. Moreover, a pilot clinical trial including five patients with anterior mandible fracture was conducted. The fractures were managed by intraoral open reduction and 3D miniplate fixation in labio-inferior position. Intraoperative interfragmentary gap, post fixation lingual splay and radiographic fracture union and complications were assessed clinically. ResultsLabio-inferior plating demonstrated less displacement (mm) of fracture fragments during screw fixation (0.059 vs. 0.079) as well as after application of masticatory load (1.805 vs. 1.860). Negligible lingual splay and less stress distribution (MPa) across fracture fragments (1.860 vs. 1.847) were appreciated in the study group as compared to control group. Clinical trial support the favorable outcome related to intraoperative and postoperative assessment parameters. ConclusionFEM analysis and clinical trial reveal better results with labio-inferior positioning of 3D miniplate when compared to labial positioning.

Pediatric Type II Tibial Spine Fractures: Addressing the Treatment Controversy With a Mixed-Effects Model.

Background:Tibial spine fractures, although relatively rare, account for a substantial proportion of pediatric knee injuries with effusions and can have significant complications. Meyers and McKeever type II fractures are displaced anteriorly with an intact posterior hinge. Whether this subtype of pediatric tibial spine fracture should be treated operatively or nonoperatively remains controversial. Surgical delay is associated with an increased risk of arthrofibrosis; thus, prompt treatment decision making is imperative.Purpose:To assess for variability among pediatric orthopaedic surgeons when treating pediatric type II tibial spine fractures.Study Design:Cross-sectional study.Methods:A discrete choice experiment was conducted to determine the patient and injury attributes that influence the management choice. A convenience sample of 20 pediatric orthopaedic surgeons reviewed 40 case vignettes, including physis-blinded radiographs displaying displaced fractures and a description of the patient’s sex, age, mechanism of injury, and predominant sport. Surgeons were asked whether they would treat the fracture operatively or nonoperatively. A mixed-effects model was then used to determine the patient attributes most likely to influence the surgeon’s decision, as well as surgeon training background, years in practice, and risk-taking behavior.Results:The majority of respondents selected operative treatment for 85% of the presented cases. The degree of fracture displacement was the only attribute significantly associated with treatment choice (P < .001). Surgeons were 28% more likely to treat the fracture operatively with each additional millimeter of displacement of fracture fragment. Over 64% of surgeons chose to treat operatively when the fracture fragment was displaced by ≥3.5 mm. Significant variation in surgeon’s propensity for operative treatment of this fracture was observed (P = .01). Surgeon training, years in practice, and risk-taking scores were not associated with the respondent’s preference for surgical treatment.Conclusion:There was substantial variation among pediatric orthopaedic surgeons when treating type II tibial spine fractures. The decision to operate was based on the degree of fracture displacement. Identifying current treatment preferences among surgeons given different patient factors can highlight current variation in practice patterns and direct efforts toward promoting the most optimal treatment strategies for controversial type II tibial spine fractures.

Posterior wall acetabular fracture fixation: A mechanical analysis of fixation methods.

Stable, anatomical fixation of acetabular fractures gives the best chance of successful outcome, while penetration of the acetabular articular surface with screws is associated with poor outcomes. Spring plates are an alternative to interfragmentary lag screws when penetration is a concern. A mechanical study comparing fracture stability and construct stiffness of three fixation methods for posterior wall acetabular fractures with transverse comminutions was performed. The three fixation methods tested were a posterior wall rim plate, a posterior wall buttress plate with separate lag screws and a posterior wall plate with two spring plates. Nine samples were tested, three for each fixation method. Two-dimensional motion analysis was used to measure fracture fragment displacement and construct stiffness. After two 6000 cycle-loading protocols, to a maximum 1.5 kN, the mean fracture displacement was 0.154 mm for the rim plate model, 0.326 mm for the buttress plate and 0.254 mm for the spring plate model. Mean maximum displacement was significantly less for the rim plate fixation than the buttress plate (p = 0.015) and spring plate fixation (p = 0.02). The rim plate was the stiffest construct 10,962 N/mm, followed by the spring plate model 5637 N/mm and the buttress plate model 4882 N/mm. Based on data obtained in this study, where possible a rim plate with interfragmentary lag screws should be used for isolated posterior wall fractures as this is the stiffest and most stable construct. When this method is not possible, spring plate fixation is a safe and a superior alternative to a posterior buttress plate method.

Arthroscopic fixation of ACL avulsion fracture in the saint pault hospital: A review of treatment outcomes: Cohort study.

BackgroundThe purpose of this research is to evaluate the results of arthroscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture, and to determine how effective such a technique is when it comes to restoring of knee function.Materials and methodsThis prospective study involves 28 patients, who underwent arthroscopic fixation of displaced ACL avulsion fractures at Saint Paul Hospital (Hanoi) from January 2014 to March 2018.ResultsThe first three weeks were not marked with any abnormalities associated with post-operative sutures and hematomas, infectious complications were not detected either. Post-operative displacement of fracture fragments did not take place among the patients involved in the study. At the 3-month follow-up, the average IKDC score was 90.7 (range: 76–100), and the average Lysholm score was 93.6 (range 82–100). The percentage of excellent scores was 42.9% (12 patients), good scores accounted for 50% (14 patients), while fair/poor scores accounted for 3.6% each (1 patient on each score). The percentage of excellent/good scores was 92.9% in total.ConclusionThis study shows that ACL avulsion fracture can be treated effectively by arthroscopic suture fixation with fiber wires. In fact, this technique may restore knee function and stability.

Arthroscopic fixation of ACL avulsion fracture in the Saint Paul Hospital: a review of treatment outcomes.

The purpose of this research is to evaluate the results of arthroscopic suture fixation with fiber wires used as treatment for ACL avulsion fracture, and to determine how effective such a technique is when it comes to restoring of knee function. This prospective study involves 28 patients, who underwent arthroscopic fixation of displaced ACL avulsion fractures at Saint Paul Hospital (Hanoi) from January 2014 to March 2018. The first 3weeks were not marked with any abnormalities associated with postoperative sutures and hematomas; infectious complications were not detected either. Postoperative displacement of fracture fragments did not take place among the patients involved in the study. At the 3-month follow-up, the average IKDC score was 90.7 (range 76-100), and the average Lysholm score was 93.6 (range 82-100). The percentage of excellent scores was 42.9% (12 patients), good scores accounted for 50% (14 patients), while fair/poor scores accounted for 3.6% each (one patient on each score). The percentage of excellent/good scores was 92.9% in total. This study shows that ACL avulsion fracture can be treated effectively by arthroscopic suture fixation with fiber wires. In fact, this technique may restore knee function and stability.

Stability of femoral neck fracture fixation: A finite element analysis

Femoral neck fractures represent a relatively uncommon injury in the non-elderly population often resulting from high-energy trauma. Clinical outcome in these patients can be improved by optimizing surgical procedures and selecting appropriate fixation methods. The aim of this study was to develop a numerical fracture model to investigate the influence of critical mechanical factors on the stability of fixation methods for femoral neck fractures. The mechanical stability of fracture fixation was assessed through employing finite element models and simulating progressive consolidation of the fracture for a vertical femoral neck fracture (i.e. Pauwels type III in which the angle between the fracture line and the horizontal plane is greater than 70°). Mechanical performance was compared among three different fixation methods (cannulated screws, dynamic hip screw with de-rotational screw, and proximal femoral locking plate). Axial femoral head displacement varied from 2.3 mm for cannulated screws to 1.12 mm for proximal femoral locking plate, although dynamic hip screw with de-rotational screw indicated a value of 0.94 mm. Considering a consolidated fracture and full weight-bearing load case, average displacements of fracture fragments were obtained of about 1.5, 3 and 70 µm for dynamic hip screw with de-rotational screw, proximal femoral locking plate and cannulated screws methods, respectively. In terms of interfragmentary movements at the fracture site, outcomes of this study demonstrated that, in agreement with our previous experimental research, the dynamic hip screw with de-rotational screw implant is a more effective choice than cannulated screws and proximal femoral locking plate techniques for vertical femoral neck fractures in young patients. Thus, one may conclude that the use of dynamic hip screw with de-rotational screw, particularly during the early stages of bone healing, could provide suitable mechanical environments that facilitate direct bone formation and shorter healing times.

There has to be an easier way: facet fracture characteristics that reliably differentiate AOSpine F1 and F2 injuries.

To identify morphologic features of isolated cervical spine facet fractures that can reliably differentiate AOSpine F1 and F2 injuries. Retrospective review of cervical spine CTs on all patients who sustained isolated cervical fractures of the facets presenting to our level 1 trauma center from August 2012 through December 2015. CTs were reviewed for facet fracture characteristics and AOSpine facet fracture classification. Association between facet fracture characteristics and AOSpine classification was assessed through multivariable logistic regression models. Fifty-six patients with cervical spine fractures isolated to the facets were included in the study. The mean age was 36 (range 9-90) years with 55.4% (n = 31) males. A significant correlation was found between subtype F1 and subtype F2 in laterality (left- or right-sided) (p = 0.004), interfacetal fracture involvement (p < 0.0001), transverse process involvement (p < 0.001), displacement of fracture fragment (p < 0.001), comminution of fracture (p < 0.0001), and vertebral arch disruption (p = 0.001). After multivariable analysis, left side laterality (p = 0.03), transverse process involvement (p = 0.01), and fracture comminution (p = 0.003) were associated with F2 fractures. Facet fractures with transverse process involvement or comminution have a higher probability of being an F2 fracture. These characteristics may be helpful when categorizing facet fractures using the AOSpine classification.

Quantitative 3-dimensional Computerized Tomography Modeling of Isolated Greater Tuberosity Fractures with and without Shoulder Dislocation.

The aim of this study was to assess differences in fracture morphology and displacement between isolated greater tuberosity (GT) fractures (i.e. fractures of the greater tuberosity without other fractures of the proximal humerus) with and without shoulder dislocation utilizing quantitative 3-dimensional CT imaging. Thirty-four CT-scans of isolated greater tuberosity fractures were measured with 3-dimensional modeling. Twenty patients (59%) had concomitant dislocation of the shoulder that was reduced prior to CT-scanning. We measured: degree and direction of GT displacement, size of the main fracture fragment, the number of fracture fragments, and overlap of the GT fracture fragment over the intact proximal humerus. We found: (1) more overlap -over the intact humerus- in patients without concomitant shoulder dislocation as compared to those with shoulder dislocation (P=0.03), (2) there was a trend towards greater magnitude of displacement between those without (mean 19mm) and those with (mean 11mm) a concomitant shoulder dislocation (P=0.07), and (3) fractures were comparable in direction of displacement (P=0.50) and size of the fracture fragment (P=0.53). We found substantial variation in degree and direction of displacement of GT fracture fragments. Variation in degree of overlap and displacement is partially explained by concomitant shoulder dislocation.

Comparative study of radiological and clinical outcomes by using single and double interlocking distal screws for humerusshaft fractures

Background: The aim of this study was to make a comparative analysis of radiological and clinical outcomes of using either one or two interlocking distal screws on ahumerus intramedullary nail for the internal fixation of humeral shaft fractures. Methods: From April 2010 to April 2015, 30 patients were enrolled with humeral shaft fractures who were operated on using intra medullary humerus nails. The patients were divided into 2 groups according to how many interlocking distal screws were used to lock the humerus nail: in group 1, a single interlocking distal screw was used in 16 patients; and in group 2, double interlocking distal screws, in 14 patients. We compared the degree of recovery of the displaced fracture fragments between the two groups. Shoulder function of patients wereassessed by modified American Shoulder and Elbow Surgeons (ASES) score. Results: We found that 15 (93.7%) fractures achieved union in group 1, and 13 (92.8%) of fractures, in group 2. There was no meaningful difference in the time to bone union and the recovery of displaced fracture fragments between the two groups. At the final follow-up, we found that the scores for shoulder joint modified ASES was 76.2 for group 1 and 79. 1 for group 2. Conclusions: This study shows that if locked appropriately, even a single screw on a humerusnail can provide satisfactory radiological union and improved clinical outcome after intramedullary nailing of humeral shaft fractures.

Role of Biplane Double Supported Screw Fixation For Fracture Neck Femur In Elderly Population: A Prospective Study

Introduction:The treatment of fracture neck femur varies according to the age of patient, the displacement of fracture fragments and the duration of the fracture. Various treatment options available for elderly are screw fixation, hemiarthroplasty and total hip arthroplasty.Materials and Methods:This is a prospective study done at authors institutes between January 2014- December 2016. 30 patients aged more than 50 years who sustained fracture neck femur were included in the study. 3 patients were lost to follow up and 2 patients died due to medical comorbidities. Out of the 25 remaining patients, 17 were males and 8 were females and they were operated by the biplane double supported screw fixation method (BDSF TECHNIQUE) and were followed up for a period of two years. The final Harris Hip Score at the last follow up was calculated.Results:Out of the 25 patients, the union was achieved in all the patients. The mean duration of union was 10 weeks. 1 patient had progressive femoral head resorption due to chondrolysis resulting in antalgic gait and unbearable pain and underwent total hip arthroplasty. The mean harris hip score was 81.2Conclusion:In elderly patients with osteoporosis and in those patients who can not afford arthroplasty or in those patients where arthroplasty is contraindicated, BDSF method is an alternate method for fixing fracture neck femur.

Results of bridging LCP along with corticocancellous autogenous bone graft and calcium hydroxyapatite blocks in gap nonunion of long bones

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; High-energy trauma is an important cause of compound fractures of long bones that in turn results into bone gap due to bone loss or high communition with resultant displacement of minute fracture fragments and hence non-union. Bone resorption or surgical excision for infection or tumour also leads to gap non-unions.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Forty-one patients having fracture of long bones of extremities with a bone gap of upto 2 inches were enrolled and were treated with autogenous bone grafting and calcium hydroxyapatite (CHA) blocks along with fixation by a locked compression plate (LCP) and plaster slab. The average follow-up period was ten months. One patient was excluded from the study due to drop out from follow up.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; In 23 (57.5%) patient’s radiological union occurred by 24-26 weeks. In 16 (40%) patients, radiological union was seen between 26-28 weeks, while in one (2.5%) patient union was seen at 30 weeks. Also, it was seen that smaller the length of gap, the faster was the union. Excellent results were seen in the majority of 25 patients (62.5%), good results in 11 patients (27.5%), fair results in 3 patients (7.5%) and poor outcome in 1 patient (2.5%). Also, it was seen that smaller the gap size, better was the outcome.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; The technique of bridge plating using internal fixator i.e. LCP along with autogenous corticocancellous bone graft and CHA blocks is a fairly good technique to treat gap non unions. It has its own advantages of avoiding complications associated with large external frame constructs. However, larger gap size limits the usefulness of this technique.&lt;/p&gt;

Does an early mobilization and immediate home-based self-therapy exercise program displace proximal humeral fractures in conservative treatment? Observational study

Nonoperative management of proximal humeral fractures (PHFs) is the most common treatment, but its functional outcome may improve with early mobilization. In frail osteoporotic patients, quick recovery of prefracture independency is mandatory. This study assessed fracture displacement in PHFs managed with conservative treatment after early mobilization and a home-based self-exercise program. We retrospectively analyzed the radiologic displacement of fracture fragments of PHFs treated conservatively with early mobilization and a home-based self-exercise program. Included were 99 patients with 26 one-part, 32 two-part, 32 three-part, and 9 four-part PHFs managed conservatively, followed by early mobilization and a home-based self-exercise program. In the x-ray examinations, the head displaced from varus into valgus 55° ± 23° to 42° ± 22°, in the normal range of anatomic values. The medial hinge displaced from medial to the diaphysis (+1 ± 6 mm) to lateral to the head (-0.6 ± 6 mm). The greater tuberosity displaced cranially from -1 ± 7 mm to 2 ± 5 mm. The Constant score at the 1-year follow-up was 79.69 ± 16.3. The home-based self-exercise program for conservative treatment of PHFs displaces the head-diaphysis angle and the medial hinge toward anatomic reduction, but there is a risk of greater tuberosity cranial displacement. Functional results are fairly good, allowing frail patients to keep on with their independency and life style. Because a large number of patients might need further physiotherapy, the quality of the home-based self-exercises should be supervised.

Three Year Review of Dorsal Plating for Complex Intra-Articular Fractures of the Distal Radius

The volar approach is commonly used for plating intra-articular fractures of the distal radius. Despite this, certain fracture configurations are more suitable for dorsal plate fixation. This technique has not gained favour due to the reported high incidence of extensor tendon irritation and attrition ruptures. With the advent of lower profile plates this risk has decreased. We report on forty-six cases performed in a tertiary hand centre between January 2011 and May 2014. Patients were identified from a database of distal radius fractures treated with open reduction and internal fixation. Pre-operative radiographs and computed tomogram (CT) scans were reviewed to classify fractures and evaluate fracture configurations. Dorsal displacement of fracture fragments was present in all cases. Records and imaging were reviewed to assess bony union and complications including tendon irritation, rupture and need for further surgery. Plate placement was dependent on the degree of comminution in each fracture component. The combination of a dorsal and radial styloid plate was used in 52% of cases. There were no cases of tendon rupture and one case of post-operative loss of reduction. Removal of metal was performed in ten patients, mainly to improve motion and for tendon irritation (four cases each). Even though technically challenging, dorsal plating is useful in cases of dorsal fragment displacement and comminution, as well as complex AO-23C3 fractures with involvement of the lunate fossa. It allows stable reduction of the dorso-ulnar fragment which is important to restore DRUJ anatomy. The rate of tendon irritation and rupture is lower when compared to earlier plate designs, and removal of metal is only necessary in a few cases.

What is the fracture displacement influence to fracture non-union in intramedullary nail treatment in subtrochanteric fracture?

IntroductionThe fracture displacement in intramedullary nail in femoral subtrochanteric fracture may cause fracture non-union. We retrospectively analysed our recent experience to clear the influence about fracture displacement in intramedullary nail in femoral subtrochanteric fracture. Materials and methodsThis study includes 36 patients in the intramedullary nail group followed up for more than 12 months; these patients suffered from femoral subtrochanteric fracture from 2009.1–2014.12 in our hospital. The operation time, amount of bleeding, length of hospital stay, fracture healing time, Harris function score of hip joint, fracture displacement, TAD and postoperative complications were summarized. ResultsThe average follow up time was 20.2 months, average operation time was 126 min, average amount of bleeding was 258 ml, average hospitalization was 13.1 days, average fracture healing time was 6.8 months, average fracture displacement was 1.23 cm, average TAD was 19.7 mm and average hip Harris function score was 82.5 points. Five cases suffered non-union. Only the fracture displacement degree made significant correlation with fracture non-union. All union patients had a fracture displacement less than 2.2 cm and all non-union patients had a fracture displacement more than 2.5 cm. ConclusionIntramedullary nail treatment must focus on fracture reduction and recovery of femoral medial support with assisted incision technique or closed cerclage wire technique when necessary. In our opinions, only the fracture displacement degree made significant correlation with bone non-union and all cases achieved bone union when it less than 2.2 cm according to our statistics. But it still need further research to find out the displacement of fracture fragments could be tolerant.

Multiplanar realignment for unstable Hangman’s fracture with Posterior C2-3 fusion: A prospective series

ObjectiveThere is lack of consensus on the preferred approach for unstable Hangman’s fracture. The associated soft tissue injuries apart from apparent bony injury add to the complexity of dislocation and needs to be addressed. Here, we evaluated the clinico-radiological characteristics and outcome of patients managed by posterior C2-3 fusion. Patients & methodsNine patients with unstable Hangman’s fracture (type II and IIA) were prospectively studied. The displacement of fractured fragments and C2-3 dislocation was studied in multiple planes. C2 pars-pedicle screw was placed to bring fractured fragments together (lag effect), which was then fused with C3 lateral masses to achieve multiplanar realignment. Clinical outcome was assessed in terms of pain (VAS score) and neurological status after surgery. Patient’s clinico-radiological status was followed up at regular intervals. ResultsPain was the predominant symptom (VAS: 8.1 ± 1.1). Only one had neurological deficit (ASIA- D). Mean VAS score improved significantly in postoperative period (1.2 ± 1.6). About two-third (66.7%) had atypical Hangman’s. In six, fractured segments were malaligned in multiple planes. Axial rotation, lateral translation and superior translation (over-riding) of fragments were seen in 4, 4 and 3 patients respectively. Two had adjacent level injuries. Reduction and realignment of fractured fragments as well as C2-3 in multiple planes could be achieved in all. Follow-up varied from 6 to 22 months (mean, 12.8 ± 5.7). Bony fusion was evident in 9 to 12 months. Three patients showed mild curvature change in subaxial spine. ConclusionThe fractures fragments may be dislocated in axial (rotation and lateral translation) apart from antero-posterior plane. It is important to study the radiology in various planes. Posterior C2-3 fusion is an effective way to achieve good realignment of bony fragments in all planes. It also addresses the instability resulting from soft tissue injury.

Comparison between absorbable pins and mini-screw fixations for the treatment of radial head fractures Mason type II-III

BackgroundThe treatment of comminuted radial head fractures can include prosthetic replacement or open reduction and internal fixation. The purpose of this study is to evaluate the results of two different internal fixation systems for Mason type II-III radial head fractures.MethodsBetween 2005 and 2015, 82 patients were treated using pins and 65 patients by mini-screws. The follow-up protocol included: a clinical evaluation 15 days after surgery, and clinical and radiographic evaluations performed at 30 and 60 day intervals, unless any complications were reported by the patient. Over a period of at least 12-months of follow-up, patients were checked and interviewed. Clinical examinations included elbow range of motion (ROM), arm, shoulder and hand Disabilities, (DASH), and the Mayo Elbow Performance Score (MEPS).ResultsSixty-one subjects who had been treated with mini-screws were clinically reviewed at a mean 47.3 ± 35.8 month of follow-up; all patients who had been treated using absorbable pins were evaluated at a mean 82.5 ± 20.6 month of follow-up. No significant statistically differences were observed between the two groups in the mean ROM, DASH, and MEPS scores. Residual pain was reported in 15.8%of the patients treated by pins and 9.2% patients treated by mini-screws. Secondary displacement of fracture fragments was observed in 8.5% patients treated by pins and 1.6% using mini-screws.ConclusionsBoth absorbable pins and mini-screws provided adequate strength and rigidity, allowing good clinical and functional scores at a mid-term follow-up. However, a higher rate of secondary displacement of the fracture fragments was reported among subjects who had been treated using absorbable pins.

Posterior Screw Fixation in Previously Augmented Vertebrae with Bone Cement: Is It Inapplicable?

ObjectiveThe purpose of this study was to determine the feasibility of screw fixation in previously augmented vertebrae with bone cement. We also investigated the influence of cement distribution pattern on the surgical technique.MethodsFourteen patients who required screw fixation at the level of the previous percutaneous vertebroplasty or balloon kyphoplasty were enrolled in this study. The indications for screw fixation in the previously augmented vertebrae with bone cement included delayed complications, such as cement dislodgement, cement leakage with neurologic deficits, and various degenerative spinal diseases, such as spondylolisthesis or foraminal stenosis. Clinical outcomes, including pain scale scores, cement distribution pattern, and procedure-related complications were assessed.ResultsThree patients underwent posterior screw fixation in previously cemented vertebrae due to cement dislodgement or progressive kyphosis. Three patients required posterior screw fixation for cement leakage or displacement of fracture fragments with neurologic deficits. Eight patients underwent posterior screw fixation due to various degenerative spinal diseases. It was possible to insert screws in the previously augmented vertebrae regardless of the cement distribution pattern; however, screw insertion was more difficult and changed directions in the patients with cemented vertebrae exhibiting a solid pattern rather than a trabecular pattern. All patients showed significant improvements in pain compared with the preoperative levels, and no patient experienced neurologic deterioration as seen at the final follow-up.ConclusionFor patients with vertebrae previously augmented with bone cement, posterior screw fixation is not a contraindication, but is a feasible option.

Biomechanical study of screw and plate fixation of a posterior malleolar fracture for osteoporosis patients in a simulation of the normal gait cycle

Objective Purpose of this research is to biomechanically compare the screw-fixed and plate-fixed posterior malleolus fracture in osteoporosis patients with fatigue loading system and space motion system in simulation gait cycle, and to give theory evidence on how to choose an internal fixation in osteoporosis patients with posterior malleolus fracture. Methods 72 osteoporotic cadaveric lower limbs were prepared to simulate Haraguchi I posterior malleolus fracture and randomized into 2 groups with 36 each. Screw group were fixed with 2 paralleled 4.0 mm titanium partial thread cancellous screws from posterior to anterior. Plate group were fixed with plate. Based on the ratio of fracture area on sagittal plane to distal tibial articular surface (S), the two groups were subdivided into three subgroups, named as screw group A, plate group A, screw group B, plate group B, screw group C, plate group C. S (screw group A, plate group A)=1/4; S (screw group B, plate group B)=1/3; S (screw group C, plate group C)=1/2. According to the height of fracture fragments, these 6 subgroups were further divided into subgroup a with height 19.3 mm and subgroup b with height 39 mm. Furthermore, 4 different conditions of gait cycle were simulated as follows: 1) specimen was loaded with 3.2 body weight (BW) at dorsiflexion angle of 12°; 2) Start-up phase: dorsiflexion angle of 5°, 3 BW; 3) neutral position, 3.6 BW; 4) maximum plantar flexion, angle of 12°, 4.5 BW. At the end of repeated loading, the displacement of fracture fragment was measured with space motion system. Results At dorsiflexion 12° and plantar flexion 15°, there was significant difference of displacement between screw and plate group with larger displacement in screw group, whatever S or H was. When ankle was at dorsiflexion of 5°, the displacement showed significant difference between screw group Aa and plate group Aa, screw group Ba and plate group Ba, screw group Bb and plate group Bb, screw group Cb and plate group Cb, with larger displacement in screw group. In neutral position, the differences were significant with larger displacement in screw group, except between screw group Bb and plate group Bb. Conclusion Plate can provide stronger fixation for osteoporosis patients with posterior malleolus fracture in most situations, but both of the two methods cannot provide stable fixation when posterior malleolus fragment was in too big area or height. Key words: Ankle injuries; Osteoporosis; Fracture fixation, internal; Biomechanics

Surgery approach for thoracolumbar burst fracture in response to posterosuperior fracture fragment of injured vertebral body

Objective To investigate the radiographic characteristics of posterosuperior fracture fragment of the injured vertebral body and its effects on the results of surgical treatment in thoracolumbar burst fractures. Methods A total of 45 patients with acute thoracolumbar burst treated by either anterior or posterior surgery from January 2014 to December 2015 were analyzed by retrospective case-control study. There were 24 males and 21 females with a mean age of 33.6 years (range, 23-52 years). Fractured segments included T12 in six cases, L1 in 15, L2 in 14, L3 in 5, and L4 in 5. Based on AO classification, there were ten cases of A3 fractures and 35 cases of A4 fractures, among which four cases of A4 were combined with B2 injuries. Eleven patients underwent anterior surgery and 34 patients posterior surgery. The operation time and intraoperative blood loss were recorded. The following parameters were also measured pre- and post-operatively, namely the displacement and inversion angle of posterosuperior fracture fragment, Cobb angle, anteroposterior diameter (APD) of spinal canal, and American spinal injury association (ASIA) neurological scale. Results All patients were followed up for 11-24 months (mean, 17 months). There were no complications except for one case of implant loosening at three months after anterior surgery. The average operation time was 138.3 minutes and intraoperative blood loss was 293.7 ml in anterior surgery while the average operation time was 77.5 minutes and intraoperative blood loss was 54.7 ml in posterior surgery (P 8 mm, the APD was much smaller in posterior surgery with only 78.5%(P 25°, the APD was significantly different in anterior surgery and posterior surgery (95.4% vs. 80.8%) (P<0.05). Conclusions Although posterior surgery for thoracolumbar burst fractures is easy to perform and has short operation time and little intraoperative blood loss, it cannot always guarantee adequate decompression of spinal canal. When the posterosuperior fragment displacement is >8 mm or when its inversion is >25°, stand-alone posterior indirect reduction technique is likely to lead to inadequacy of canal restoration. In this case, anterior surgery should be considered in order to achieve more complete canal decompression. Therefore, this radiographic characteristic of the posterosuperior fragment could serve as an approach reference for thoracolumbar burst fractures. Key words: Spinal fractures; Thoracic vertebrae; Lumbar vertebrae; Fracture fixation, internal