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Interlocking of intramedullary nails is a challenging procedure in orthopedic trauma surgery. Numerous methods have been described to facilitate this process. But they are exposed patient and surgical team to X-rays or involves trial and error. An accurate and non-invasive method has been provided to easily interlocking intramedullary nails. By transferring a safe visible light inside the nail, a drilling position appears which use to drilling bone toward the nail hole. The wavelength of this light was obtained from ex-vivo spectroscopy on biological tissues which has optimal transmission, reflectance, and absorption properties. Moreover, animal and human experiments were performed to evaluate performance of the proposed system. Ex-vivo performance experiments were performed successfully on two groups of cow and sheep samples. Output parameters were procedure time and drilling quality which there were significant differences between the two groups in procedure time (P < 0.05). But no significant differences were observed in drilling quality (P > 0.05). Moreover, an In-vivo performance experiment was performed successfully on a middle-aged man. To compare the provided method, targeting-arm, and free-hand techniques, two human experiments were performed on a middle-aged and a young man. The results indicate the advantage of the proposed technique in the procedure time (P < 0.05), while the drilling quality is equal to the free-hand technique (P = 0.05). Intramedullary nail holes laser indicator is a safe and accurate method that reduced surgical time and simplifies the process. This new technology makes it easier to interlocking the intramedullary nail which can have good clinical applications., (© 2021. The Author(s).)

Objectives: This study aims to mechanically compare five different extra-focal bi-cortical pin configurations (using two and three pins) employed for fixation of a simulated unstable extra-articular distal radius fracture with dorsal comminution using a sawbone model., Materials and Methods: This in vitro mechanical study was conducted between June 2019 and July 2019. A standard fracture model (Arbeitsgemeinschaft für Osteosynthesefragen [AO] type 23-A3.3) was created using a fourth generation composite artificial radius bone. Five groups with two- and three-pin configurations were tested under axial, volar, and dorsal loading with a universal test device. Mean stiffness values were compared statistically., Results: Comparison of stiffness values from axial and volar loading tests between groups in paired comparison showed no statistically significant difference (p=0.194 and p=0.086, respectively). Dorsal loading tests showed statistically significant difference between the groups in pairwise comparison (p=0.002). Three-pin groups (Groups 3, 4, and 5) had higher stiffness values compared to two-pin groups (Groups 1 and 2) in dorsal loading tests (p=0.001). Three-pin configuration test groups with two divergent or convergent pins from the radial styloid performed better compared to both two-pin groups (p=0.01, p=0.002) in dorsal loading tests., Conclusion: Our data demonstrated that the three-pin configuration with two divergent or convergent Kirschner wires from the styloid and a third wire from the dorsal/ulnar cortex had higher stiffness values compared to two-pin configurations in dorsal loading tests. When indicated, we suggest the use of a three-pin construct. Particularly in cases with a risk of volar angulation, we recommend a three-pin configuration with two divergent or convergent bi-cortical Kirschner wires.

Objectives: This study aims to evaluate the effectiveness of silver ion doped calcium phosphate-based ceramic nano powder-coated titanium pins in preventing bacterial colonization., Materials and Methods: A total of 66 titanium pins were divided into three groups of 22 implants. The first group was coated with silver ion doped calcium phosphate-based ceramic powder by using electrospray method. The second group was coated with pure hydroxyapatite (HA), and the remaining pins were used without any coating. The remaining 22 pins were used without any coating. Staphylococcus epidermidis clinical isolate was used for the study. Each pin was placed in 1x10 4 CFU/mL bacterial suspension containing tube and at 24 h quantitative culture of bacteria on the broth and on the pins were performed. Free silver ions were determined by atomic absorption method. The antibacterial culture tests were repeated on Day 2 and Weeks 2, 4, 6, and 8., Results: Bacterial growth was statistically higher in broth containing uncoated pins, compared to broth media containing silver ion doped HA-coated, and pure HA-coated pins at 24 h (p=0.036 and p=0.009, respectively). The release of bacteria from silver doped HA-coated pins was statistically less, compared to pure HA-coated pins and uncoated pins (p=0.039 and p=0.002, respectively). No significant differences were observed between the HA-coated and uncoated pin groups. Minimum inhibitory concentration levels for silver ion doped powder was 8 μg/mL for coagulase-negative Staphylococcus. No free silver ions were detected in the broth media., Conclusion: Silver ion doped nano size calcium phosphate-based powder-coated titanium pins reduced the bacterial colonization significantly. Using silver ion doped materials in the body can be a good option to prevent from implant related infections.

Internal fixation such as elastic stable intramedullary(ESIN) nail and submuscular plate (SMP) is gaining popularity for femoral shaft fractures in school-aged children. However, external fixation (ExFix) might be a valuable option for the distal third femoral shaft fractures, where the fracture heals rapidly, but it is crucial to avoid angular malunion. This study aims to compare the clinical outcomes, postoperative complications of distal third femoral shaft fractures in school-aged children treated by ESIN versus ExFix.Patients aged 5 to 11 years with distal third femoral shaft fractures treated at our institute from January 2014 to January 2016 were included and categorized into ESIN (n = 33) and ExFix (n = 38) group. The preoperative data, including baseline information of the patients, radiographic parameters, and type of surgical procedure, were collected from the hospital database, and postoperative data, including complications, were collected during the follow-up visit.In all, 33 patients (average, 8.0 ± 2.1 years, male 20, female 13) in the ESIN group and 38 patients (average, 8.3 ± 2.3 years, male 23, female 15) in the ExFix group were included in this study. There was significantly less operative time for the ExFix group (45.4 ± 7.8 min) as compared to the ESIN group (57.8 ± 11.3 min) (P < .01), reduced estimated blood loss (EBL) in the ExFix group (9.9 ± 3.5) as compared to the ESIN group (16.4 ± 6.5) (P < .01). As for the frequency of fluoroscopy, there was a significant difference between the ExFix group (13.9 ± 2.4) and the ESIN group (15.5 ± 3.2) (P = .02). The rate of major complications was not significantly different between the 2 groups (P = .19). The rate of implant irritation was significantly higher in the ExFix group (28/38, 73.7%) than the ESIN group (12/33, 36.4%) (P < .01). The rate of surgical site infection (SSI) is significantly higher in the ExFix group (18/38, 47.4%)) than the ESIN group (1/33, 3%) (P < .01). The rate of scar concern was significantly higher in the ExFix (9/38, 23.7%) than the ESIN (2/33, 6.1%), (P = .04). According to the Flynn scoring system, 30(90.9%) patients in the ESIN group and 24(89.5%) patients in the ExFix group were rated as excellent. None of the patients had poor outcomes.Both ESIN and ExFix produced satisfactory outcomes in distal third femoral shaft fractures. ExFix remains a viable choice for selected cases, especially in resource-challenged and austere settings.

Background: Elastic intramedullary nails (ESIN) have been the treatment of choice in many long bone fractures in children for more than 20 years. The introduction of ESIN has drastically reduced tissue traumatization during fracture fixation procedures and decreased the risk of growth cartilage damage, as well as allowing for preservation of the natural biology of closed fracture healing. The objective of the present report is to draw attention to a small group of patients with bone mineralization disorders, who consequently demonstrate decreased mechanical resistance of the skeletal system, in whom indications for using ESIN fixation are limited., Material and Methods: The study group consisted of 6 patients who met the criteria for using ESIN fixation, but did not demonstrate a satisfactory outcome. The inclusion criteria included age below 18 years, appropriate ESIN nail insertion technique with correct calculation of nail diameter (2/5 of the medullary canal diameter), body mass &lt; 50 kg and achieving appropriate prebending that is the prerequisite of three-point intramedullary support. The patients' medical records and radiographs were analyzed and they were invited for clinical and radiological follow-up examinations., Results: All six patients demonstrated a gradually increasing bending deformity of the long bone axis. Additionally, in three patients, there was intrusion of terminal parts of the nails into the bone. In one patient with bone fibrous dysplasia, the proximal epiphysis was perforated by the flattened ends of the nails. In all patients, the removal of the ESIN fixation was followed by single or double-level corrective osteotomies and Rush pin fixation., Conclusion: In cases of long bone fractures in children with metabolic bone disorders in whom the bone structure is weakened and the bones themselves are easily deformed, more rigid intramedullary fixation with Rush or Fassier-Duval type nails as primary osteosynthesis should be considered.

In situ pinning of slipped capital femoral epiphysis (SCFE) is a safe and effective treatment modality, but often results in residual deformity leading to femoroacetabular impingement, which may limit patient activities and predispose to early onset arthritis. Enhanced understanding of the implications of femoroacetabular impingement and new surgical techniques have prompted interest in treating post-slipped capital femoral epiphysis deformity to both improve current symptoms and delay or prevent hip arthrosis., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: More elderly patients are suffering from intertrochanteric fractures. However, the choice of internal fixation is still controversial, especially in the treatment of unstable intertrochanteric fracture; thus, previous implants continue to be improved, and new ones are being developed. The purpose of our study was to compare the biomechanical advantages between the zimmer natural nail (ZNN) and proximal femoral nail antirotation-II (PFNA-II) in the treatment of elderly reverse obliquity intertrochanteric fractures., Methods: A three-dimensional finite element was applied for reverse obliquity intertrochanteric fracture models (AO31-A3.1) fixed with the ZNN or PFNA-II. The distribution, peak value and position of the von Mises stress and the displacement were the criteria for comparison between the two groups., Results: The stresses of the internal fixation and femur in the ZNN model were smaller than those in the PFNA-II model, and the peak values of the two groups were 364.8 MPa and 171.8 MPa (ZNN) and 832.3 MPa and 1795.0 MPa (PFNA-II). The maximum amount of displacement of the two groups was similar, and their locations were the same, i.e., in the femoral head vertex (3.768 mm in the ZNN model and 3.713 mm in the PFNA-II model)., Conclusions: The displacement in the two models was similar, but the stresses in the implant and bone were reduced with the ZNN. Therefore, the ZNN implant may provide biomechanical advantages over PFNA-II in reverse obliquity intertrochanteric fractures, as shown through the finite element analysis. These findings from our study may provide a reference for the perioperative selection of internal fixations.

Background: The aim of this study was to compare the clinical and radiological results of the proximal femoral nail antirotation (PFNA) with those of the dynamic hip screw (DHS) and percutaneous compression plate (PCCP) in the treatment of simple pertrochanteric fractures., Methods: A total of 203 patients were included in the study. PFNA fixations were performed in 73 patients (PFNA group), DHS in 68 patients (DHS group), and PCCP in 62 patients (PCCP group). The main outcome measurements were perioperative properties, the Harris hip score, changes in the neck-shaft angle, and loss of the abductor muscle strength. Data were compared between the groups., Results: The mean estimated total blood loss and the number of patients receiving the blood transfusion rate in the PFNA group were statistically significantly lower. The mean operation and fluoroscopy times in the PCCP group were statistically significantly higher. The mean loss of the abductor muscle strength and changes in the neck-shaft angle in the PFNA group were statistically significantly higher. The mean Harris hip scores were similar., Conclusion: Our findings demonstrated that although PFNA was superior with regard to the perioperative data, DHS and PCCP were superior in maintaining the reduction and the abductor muscle strenght. All three implants were similar and had satisfactory functional outcomes.

Background and objectives : Pediatric tibial shaft fractures often have satisfactory outcomes after closed reduction and casting. However, surgical treatment may be required in unstable or open fractures. Titanium elastic nails (TENs) are a good option for the surgical treatment of pediatric tibial fractures due to their advantages such as short hospitalization periods, easy applicability, early weight bearing, and early union. In this study, we evaluated radiological and functional outcomes in pediatric patients with tibial shaft fractures that underwent fixation with TENs. Materials and methods : A total of twenty tibial shaft fractures that were treated with TENs in our clinic between 2013 and 2017 were retrospectively reviewed. The mean age at injury was 8.9 ± 2.78 (range of 3-14) years. Seven (35%) out of 20 fractures were open fractures, of which one fracture was classified as Grade I and six fractures were classified as Grade II. In each patient, antegrade nailing was performed by inserting a TEN in the medial and another TEN in the lateral side of the proximal metaphysis. Clinical outcomes including union, alignment, leg-length inequality, and complications were evaluated using modified Flynn's criteria. Results : The mean time to union was 10.85 ± 3.39 (range of 6-20) weeks. No patient had a sagittal or coronal angulation of over 10°. One patient had a leg-length inequality of 10 mm. Among three patients with open fractures, two of them had superficial wound infections and the other patient had a deep wound infection. All the infections were successfully treated with appropriate antibiotic therapies. Four other patients had pin tract irritation that required no intervention. No significant difference was observed between patients with open and closed fractures with regard to the clinical and radiological findings although patients with open fractures had a significantly higher complication rate compared to patients with closed fractures ( p < 0.05). No patient had a restricted range of motion of the ankle and knee joints. Twelve (60%) patients had an excellent outcome, and eight (40%) patients had a satisfactory outcome. Conclusions : Intramedullary fixation with TENs provides favorable outcomes and reduced complication rates in the treatment of unstable pediatric tibial shaft fractures that cannot be reduced with conservative treatment modalities or cannot be casted due to the presence of an edema or open wound., Competing Interests: The authors declare no conflict of interest.

To compare the efficacy of curettage and bone grafting combined with elastic intramedullary nailing (EIN) vs curettage and bone grafting in the treatment of long bone cysts in children and to clarify the necessity of using EIN in the treatment of bone cysts.Sixty-two patients were involved in this study from Jan. 2009 to Sept. 2017 (43 males, 19 females; 27 humeri, 35 femurs); the patients were assigned to an EIN group, comprising 30 patients who underwent curettage and bone grafting combined with EIN, or to a non-elastic intramedullary nailing (NEIN) group, comprising 32 patients who underwent curettage and bone grafting alone. The prognosis of the 2 groups was assessed with reference to the standard of Capanna.No statistically significant differences in sex, age, location, activity, pathological fracture, cyst volume, operative time and intraoperative blood loss were found between the 2 groups (P > .05). The effective rate was 90.0% in the EIN group and 68.8% in the NEIN group, and the difference was statistically significant (P < .05).Compared to simple curettage and bone grafting, curettage and bone grafting combined with EIN treatment can significantly improve the prognosis of children with bone cysts. It is recommended that EIN be added to bone cyst curettage and bone grafting.

The aim of this study was to clinically compare the therapeutic effects of internal fixation using a third-generation Gamma Long Nail (TGLN) with that of INTERTAN in the treatment of Seinsheimer Type V subtrochanteric femoral fractures in elderly patients.The therapeutic effect of internal fixation with TGLN, compared with that with INTERTAN, was retrospectively analyzed in elderly patients diagnosed with Seinsheimer Type V subtrochanteric fracture. Twenty-five cases were divided into 2 groups based on the fixation devices: the TGLN group (13 cases; 5 men and 8 women) and the INTERTAN group (12 cases; 5 men and 7 women). Patients were followed up postoperatively, and their clinical history, intraoperative blood loss, fracture healing, Harris Hip Scores, and postoperative complications were recorded and compared.Patients in the TGLN group had shorter operation time and less intraoperative blood loss, compared with those in the INTERTAN group (P < .05). There were no significant between-group differences in postoperative complications, fracture healing time and Harris Hip Scores during the follow-up (P > .05).

Objectives: The halo ring can be applied in children, through skeletal traction or a halo vest device, to treat many cervical spine pathologies, including traumatic injuries and pathologies related to deformities. However, the procedure is associated with various complications, such as infection, pin loosening, and respiratory and neurological problems. Although widely studied in adults, the best pin insertion site in children and the correlations of pin insertion sites with outcomes and complications have not been completely elucidated. This study aimed to determine alternative pin placement sites based on a morphological analysis of the infant skull by computerized tomography (CT)., Methods: An analytical-descriptive study was performed using 50 CT scans from children. The Wilcoxon and Friedman tests were used., Results: A linear and directly proportional relation was found between cranial thickness and patient age. The average thicknesses of the anterior points across all ages analyzed ranged from 4.16 mm to 4.98 mm. The thicknesses of the posterior points varied from 3.94 mm to 4.27 mm. Within each age range, points 1 cm above the standard insertion sites had thicknesses similar to those of the standard sites, and points 2 cm above the standard insertion sites had thicknesses greater than those of the standard sites., Conclusions: The cranial thickness at all points increases linearly with age. Points 1 and 2 cm above the standard insertion sites are viable alternatives for the placement of halo pins. Preoperative CT can aid in choosing the best positioning sites for pins in the skull.

This study aims to investigate the clinical effect of the combined an additional locking plate with bone graft based on retaining the original intramedullary nail for the treatment of lower limb nonunion.From June 2008 to December 2012, 39 patients were admitted and treated, who developed non-infectious bone nonunion after intramedullary nail fixation for long bone fracture in the lower limb. Additional locking plate and autogenous iliac bone grafting were performed for these patients, in which the original intramedullary nail was retained. Follow-ups were performed once at postoperative months 1, 2, 3, 6, and 12, and every year onwards. During these follow-ups, imaging and clinical function examinations were performed, in order to observe callus growth and the fractured limb functions.All patients have been followed-up, in which the duration of these follow-ups ranged between 8 and 24 months. All patients gained bony union within 6 to 11 months, and the healing rate was 100%. Radiographic healing time ranged between 8 and 15 months. Full weight-bearing time ranged between 2 and 10 months. According to Harris hip scores and Hospital for Special Surgery (HSS) Knee joint scores, 17 cases were excellent, 2 cases were good, and 1 case was acceptable; with an excellent and good rate of 95.00%. According to HHS score for the knee, 15 cases were excellent, 3 cases were good, and 1 case was acceptable; with an excellent and good rate of 94.74%.The combined treatment of the additional blocking plate with bone grafting based on retaining the original intramedullary nail for bone nonunion could effectively eliminate lateral and rotatory instability of the fractured ends. This surgical method had a short operation time, high healing rate and other advantages.

Background: We assessed the effect on the torsional stability by different pin diameters and varied pin configurations in a biomechanical supracondylar humerus fracture model., Methods: After scanning a model of a pediatric humerus, the image was imported into software. Variable pin trajectories were planned. Acrylonitrile butadiene styrene plastic models were 3-dimensionally printed with predetermined pin trajectories. Models were osteotomized and potted with a polyurethane resin. Five-pin configurations were designed to test coronal and sagittal patterns of pin placement. Each included 3 lateral pins and a medial pin. Pin diameters of 1.6, 2.0, and 2.4 mm were tested in all configurations. Three models for each pin diameter/configuration were tested to ensure uniformity. Stability of the construct was tested to determine the torque needed to deflect the osteotomy 10 degrees in internal/external rotation. Each model was tested 3 times., Results: In all models/configurations, the 2.4 mm pin diameter was statistically stiffer than 1.6 mm diameter pins; this lost statistical significance in certain patterns when comparing 2.0- and 2.4-mm pins. When comparing a divergent to a parallel configuration in the coronal plane, there was no significant difference in stability when pin diameter or number were controlled. The convergent pin configuration was, in general, the least stable pattern. Use of a medial pin conferred statistically significant stiffness throughout most models as demonstrated with pin deletion. Use of 2 pins was significantly less stiff than most 3-pin models., Conclusions: Larger pin diameters confer greater stiffness among all patterns. The use of 3 lateral and 1 medial pin was not statistically different than 2 lateral and 1 medial pin in our models. Both patterns were stiffer than 3 lateral pins only or other fewer pin constructs. The alignment of pins in the sagittal plane did not affect overall construct stiffness.

Background: Vertical shear fractures are unstable and potentially life-threatening injuries that require urgent reduction and stabilization. The aim of this study was to compare the biomechanical efficacy of three different external fixation pin configurations for vertical shear pelvic fractures in a cadaveric model. We hypothesized that a modified external fixation pin configuration with a crestal (CR) pin in the stable hemipelvis and bilateral supra-acetabular (SA) pins provides the greatest overall stability to axial loading., Methods: The force to failure within a standard standing axial load (maximum 650 N) was tested on 10 human cadaveric pelvises with vertical shear fractures. Three pin configurations were compared including iliac crest (IC), SA and a modified SA frame with a third CR pin on the stable hemipelvis. Both displacement at the posterior pelvis at 650 N and force to failure of >25 mm displacement was recorded., Results: The mean force to failure was highest with CR (499 N), then IC (350 N) and then SA (265 N) pin configurations, being statistically non-significant (P = 0.165). The minimum force to failure followed a similar trend with 296, 68 and 43 N for CR, IC and SA, respectively. About 1/4 CR, 1/4 IC and 2/9 SA pins sustained 650 N or more without failure., Conclusion: It was shown that this new design may reliably withstand a seated physiological load of 250 N. However, none of the three pin configurations tested can reliably withstand a standing load of 650 N. Further experiments are needed to quantify these findings under physiological loading., (© 2018 Royal Australasian College of Surgeons.)

Background: Hip fracture patients in general are elderly and they often have comorbidities that may necessitate anticoagulation treatment, such as warfarin. It has been emphasized that these patients benefit from surgery without delay to avoid complications and reduce mortality. This creates a challenge for patients on warfarin and especially for those with trochanteric or subtrochanteric hip fractures treated with intramedullary nailing, as this is associated with increased bleeding compared to other types of hip fractures and surgical methods. The aim of the study was to evaluate if early surgery (within 24 h) of trochanteric or subtrochanteric hip fractures using intramedullary nailing is safe in patients on warfarin treatment after fast reversal of the warfarin effect., Methods: A retrospective case-control study including 198 patients: 99 warfarin patients and 99 patients without anticoagulants as a 1:1 ratio control group matched for age, gender and surgical implant. All patients were operated within 24 h with a cephalomedullary nail due to a trochanteric or subtrochanteric hip fracture. All patients on warfarin were reversed if necessary to INR ≤ 1.5 before surgery using vitamin K and/or four-factor prothrombin complex concentrate (PCC). Per- and postoperative data, transfusion rates, adverse events and mortality was compared., Results: There were no significant differences in the calculated blood-loss, in-house adverse events or mortality (in-house, 30-day or 1-year) between the groups. There were no significant differences in the pre- or peroperative transfusions rates, but there was an increased rate of postoperative transfusions in the control group (p = 0.02)., Conclusion: We found that surgical treatment with intramedullary nailing within 24 h of patients with trochanteric or subtrochanteric hip fractures on warfarin medication after reversing its effect to INR ≤ 1.5 using vitamin K and/or PCC is safe.

Background: To ascertain whether the tip-apex distance (TAD), calcar referenced TAD (CalTAD), and the sum of both (TADcalTAD) are predictive measurements of mobilisation of the cephalic screw in patients with trochanteric hip fractures., Methods: Between 2014 and 2015, 68 patients (mean age 86 years, 45 females, 23 males) with a trochanteric hip fracture underwent intramedullary nailing. The TAD and CalTAD were measured, and for each parameter, we calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV)., Results: There is evidence of a statistically significant association between a TAD and CalTAD greater than 25 mm and a TADcalTAD greater than 50 mm and mobilisation of the cephalic screw. All measurements have similar sensitivity, but the TAD presents the highest specificity (p < 0.01)., Conclusion: To avoid the risk of mobilisation of the cephalic screw and possible subsequent failure of the construct, surgeons should strive for a TAD and CalTAD less than 25 mm and a TADcalTAD less than 50 mm when using intramedullary fixation.

Background: For a distal tibial spiral fracture combined with a non-displaced posterior malleolar fragment (PMF), we proposed a hypothesis that the treating surgeon could assess the size of the PMF to determine the need for stabilizing that structure first before rodding the tibia., Materials and Methods: Fifty 3-D models (22 females) of combined distal tibial and posterior malleolar fractures from one trauma center were reconstructed. In each case, a virtual tibial intramedullary nail (vIM nail) with three distal anteroposterior (AP) locking screws (S 13 , S 15 and S 37 , the number indicating the distance from the screw to the nail tip) were inserted into the center of the tibial canal and ended on top of the distal tibial physeal scar. Contact between the screws and the PMF was defined as causing PMF displacement. The relationship between PMF secondary displacement and traumatic anatomic factors (the fragment area and height of the PMF) was explored. Then, the parameters were justified by analyzing intraoperative radiographs of 35 cases treated by nail with single locking screw (S 15 ) design., Results: In the analog experiment, multiple logistic regression analysis revealed that the height of the PMF could confidently predict the risk of fragment displacement (S 13 : odds ratio [OR] 1.18, 95% confidence interval [CI] 1.06-1.32; S 15 : OR 1.15, 95% CI 1.05-1.27). Regarding the height of the PMF, the receiver operating characteristic established a cut-off value of 31.2 mm for preliminary fixation of the fragment with 88.89% sensitivity and 88.89% specificity. In the operation group the nail stopped on the top of distal tibial physeal scar, no PMF secondary displacement occurred when the PMF height was less than 31.2 mm. However, the incidence of secondary displacement was 93.33% when the height of the PMF exceeded 31.2 mm., Conclusion: When the distal tibial physeal scare was set as the limit of nail insertion depth, the height of the PMF could be used as a reliable reference predicting the risk of PMF secondary displacement caused by distal anteroposterior locking screw.

Objectives: No studies have assessed the effects of parameters associated with insertion temperature in modern self-drilling external fixation pins. The current study assessed how varying the presence of irrigation, insertion speed, and force impacted the insertion temperatures of 2 types of standard and self-drilling external fixation half pins., Methods: Seventy tests were conducted with 10 trials for 4 conditions on self-drilling pins, and 3 conditions for standard pins. Each test used a thermocouple inside the pin to measure temperature rise during insertion., Results: Adding irrigation to the standard pin insertion significantly lowered the maximum temperature (P <0.001). Lowering the applied force for the standard pin did not have a significant change in temperature rise. Applying irrigation during the self-drilling pin tests dropped average rise in temperature from 151.3 ± 21.6°C to 124.1 ± 15.3°C (P = 0.005). When the self-drilling pin insertion was decreased considerably from 360 to 60 rpm, the temperature decreased significantly from 151.3 ± 21.6°C to 109.6 ± 14.0°C (P <0.001). When the force applied increased significantly, the corresponding self-drilling pin temperature increase was not significant., Conclusions: The standard pin had lower peak temperatures than the self-drilling pin for all conditions. Moreover, slowing down the insertion speed and adding irrigation helped mitigate the temperature increase of both pin types during insertion.

Background: Retrograde intramedullary fibular nail fixation is being utilized with increasing frequency, particularly in patients at higher risk of wound complications. The purpose of this anatomic study was to assess the relative risk to nearby anatomic structures when implanting a contemporary retrograde locked intramedullary fibular nail., Methods: Ten human cadaveric lower extremities were instrumented with a fibular nail. The cadavers were dissected. The shortest distance, in millimeters (mm), between the site of procedural steps and nearby named structures of interest (ie, sural nerve, superficial peroneal nerve, and the peroneal tendons) was measured and recorded. Levels of risk were assigned based on observed distances as high (0 to 5 mm), moderate (5.1-10 mm), and low (greater than 10 mm)., Results: The peroneus brevis (PB) tendon was found to be less than 5.0 mm from the distal skin incision in all specimens. When reaming and inserting the nail through the distal fibula aperture, the PB was less than 5.0 mm in 6 specimens. The peroneus longus tendon was at moderate to high risk when inserting both the proximal and distal syndesmotic screws in 9 specimens. The superficial peroneal nerve was at high risk when inserting an anterior to posterior distal locking screw in 7 specimens. The sural nerve was at low risk for all procedural steps. No structures were violated or damaged during any portion of the fibular nail instrumentation., Conclusion: The peroneal tendons and superficial peroneal nerve were at the highest risk; however, no structures were injured during instrumentation., Clinical Relevance: The current findings indicate that strict adherence to sound percutaneous technique is needed in order to minimize iatrogenic damage to neighboring structures when performing retrograde locked intramedullary fibular nail insertion. This includes making skin-only incisions, blunt dissection down to bone, and maintaining close approximation between tissue protection sleeves and bone at all times.

Background Forearm fractures in pediatric population is usually managed conservatively. Unstable fractures need operative intervention like closed or open intramedullary nailing or open reduction and internal fixation with plates and screws. However, there is no consensus regarding the method of treatment according to age group. Objective To standardize the use of elastic nailing system as effective form of treatment in terms of function, cost and lower complications as compared to widely used titanium nails in developed countries.Method Sixty eight pediatric patients with both bone forearm diaphyseal fractures were managed with closed reduction and intramedullary fixation with rush nail or k-wire and followed at least for 6 months for evaluation of radiological and functional outcome. Result Patients were divided into two age groups, Group A for age of 5 to 9 years (26 patients) and Group B for age of 10-15 years (42 patients). The mean time for union for Group A patient was 7.31 weeks which was significantly lower than that of Group B patients of 9.33 weeks (p-value < 0.05). All the patients in Group A had excellent outcome and 36 (85.7%) patients had excellent outcome and 6 (14.3%) had good outcome in Group B. 5 out of 68 cases (7.35 %) had minor complications (2 in Group A and 3 in Group B). The mean time for implant removal was 17.9 weeks in Group A and 22.9 in Group B. Conclusion Intramedullary fixation for unstable diaphyseal both bone fractures of forearm is safe and cost effective method of treatment with good to excellent functional outcome with union time being significantly lower in younger age group.

Case: A 75-year-old man underwent intramedullary nailing for an unstable intertrochanteric fracture of the left hip. After surgery and postoperative recovery, he was transferred to a rehabilitation ward. He was able to mobilize at 2 days postoperatively; at 2 weeks postoperatively, he developed the sudden onset of tachycardia, hypotension, and a large hematoma on the left thigh. Following immediate resuscitation, a computed tomography (CT) angiogram demonstrated a bleed from a branch of the profunda femoris artery. The 3-dimensional CT reconstruction implicated the displaced lesser trochanter osseous fragment as the cause of the hemorrhage., Conclusion: Surgeons should be aware of this rare complication and the possible etiology of fracture displacement as the cause of a delayed-onset bleed after intramedullary nailing, and they should also be cognizant of the subsequent optimal management.

Aims: The aim of this paper is to review the evidence relating to the anatomy of the proximal femur, the geometry of the fracture and the characteristics of implants and methods of fixation of intertrochanteric fractures of the hip., Materials and Methods: Relevant papers were identified from appropriate clinical databases and a narrative review was undertaken., Results: Stable, unstable, and subtrochanteric intertrochanteric fractures vary widely in their anatomical and biomechanical characteristics, as do the implants used for their fixation. The optimal choice of implant addresses the stability of the fracture and affects the outcome., Conclusion: The treatment of intertrochanteric fractures of the hip has evolved along with changes in the design of the implants used to fix them, but there remains conflicting evidence to guide the choice of implant. We advocate fixation of 31A1 fractures with a sliding hip screw and all others with an intramedullary device. Cite this article: Bone Joint J 2017;99-B:128-33., (©2017 The British Editorial Society of Bone & Joint Surgery.)

Surgeons in low-resource settings manage an increasing number of patients presenting with high-energy fractures. The number of surgeons and the operating time available are frequently not adequate to treat these fractures in a timely manner. A common cause of delay in treating fractures is waiting for the patient to accumulate sufficient funding to pay for the surgery, including the surgical implant. The donation of the SIGN intramedullary nail interlocking screw system obviates a major delay in timing of surgery. The SIGN intramedullary nail has been designed to be used in low-resource settings as it can be placed without fluoroscopy or electricity. The SIGN-trained surgeons are very skillful in hand reaming the canal, placing the nail, and interlocking screws without fluoroscopy. As more is learned about fracture healing, the SIGN system continues to evolve. The SIGN system is expanding to include deformity correction and soft tissue coverage.

Background: Elastic stable intramedullary nailing (ESIN) is accepted widely for treatment of diaphyseal femur fractures in children. However, complication rates of 10 to 50 % are described due to shortening or axial deviation, especially in older or heavier children. Biomechanical in vitro testing was performed to determine whether two modified osteosyntheses with end caps or a third nail could significantly improve the stability in comparison to classical elastic stable intramedullary nailing in a transverse femur fracture model., Methods: We performed biomechanical testing in 24 synthetic adolescent femoral bone models (Sawbones®) with a transverse midshaft (diaphyseal) fracture. First, in all models, two nails were inserted in a C-shaped manner (2 × 3.5 mm steel nails, prebent), then eight osteosyntheses were modified by using end caps and another eight by adding a third nail from the antero-lateral (2.5-mm steel, not prebent). Testing was performed in four-point bending, torsion, and shifting under physiological 9° compression., Results: The third nail from the lateral showed a significant positive influence on the stiffness in all four-point bendings as well as in internal rotation comparing to the classical 2C configuration: mean values were significantly higher anterior-posterior (1.04 vs. 0.52 Nm/mm, p < 0.001), posterior-anterior (0.85 vs. 0.43 Nm/mm, p < 0.001), lateral-medial (1.26 vs. 0.70 Nm/mm, p < 0.001), and medial-lateral (1.16 vs. 0.76 Nm/mm, p < 0.001) and during internal rotation (0.16 vs. 0.11 Nm/°, p < 0.001). The modification with end caps did not improve the stiffness in any direction., Conclusions: The configuration with a third nail provided a significantly higher stiffness than the classical 2C configuration as well as the modification with end caps in this biomechanical model. This supports the ongoing transfer of the additional third nail into clinical practice to reduce the axial deviation occurring in clinical practice.

Objectives: This study aims to investigate whether there is any significant difference in bending resistance between titanium and stainless steel locking screws of femur nails and to review deformation of locking screws which is a common problem in interlocking nailing., Materials and Methods: In this study, a total of 60 pieces of 5 mm major diameter titanium and stainless steel locking screws were used as six groups in three different thread depth structures (high threaded, low threaded, and unthreaded). Three-point bending tests were conducted on steel screws placed inside stainless steel tube with 30 mm inner diameter, which imitated the level of lesser trochanter. We used an axial compression testing machine in order to determine the yield points that permanent deformation occurred in the locking screws., Results: For low threaded locking screws, which are the most frequently used thread type for locking screws, the mean bending yield points were 1413 N on the titanium screws and this level was below 1922 N (2.8 BW) of level walking loading on femur for 70 kg person. On low threaded stainless screws, bending resistance was 2071 N, which was above the value of 1922 N. For high threaded locking screws, the mean bending yield points were 874 N on the titanium screws and 556 N on stainless screws., Conclusion: In comminuted femur shaft fractures (in full load bearing conditions), using stainless steel locking screws is better instead of titanium screws to avoid locking screw deformation since low threaded stainless steel screws were 46.5% more resistant to bending deformation than titanium ones. Stainless steel or titanium high threaded locking screws may only be carefully used in non-comminuted fractures.

Objectives: This study aims to investigate which intramedullary nail is biomechanically better for establishing interfragmentary rotational stability., Materials and Methods: Thirty composite femurs were utilized in this study. We analyzed interfragmentary rotational arc displacements between 10 Nm external-6 Nm internal torques and 6 Nm external-6 Nm internal torques which imitate rotation torques while walking on a flat surface and descending stairs by administering 10 interlocking nails, 10 compression nails, and 10 Mehmet anti-rotation nails with tube compression., Results: Maximum interfragmentary rotation arc displacement between 10 Nm external rotation and 6 Nm internal rotation torques was mean 1.64 mm in the Mehmet nail compressed by 7 Nm torque wrench. This value was lower by 309% (6.72 mm) from interlocking nail (p=0.000), 201% (5.42 mm) from compression nail compressed by 2.5 Nm torque wrench (p=0.000), and 26% (1.92 mm) from compression nail compressed by 7 Nm torque wrench (p>0.05)., Conclusion: In axially stable transvers and short oblique femur fractures, Mehmet nail is superior to other intramedullary nails with limited movement between locking screw and hole, more interfragmentary compression without locking screw deformation, and no proximal nail migration.

Objective: Several clinical studies have reported that the use of hydroxyapatite- (HA) coated pins enhance external fixation. Although these studies have demonstrated higher extraction torques and lower rates of pin loosening with HA coating, there is little evidence to suggest that these biomechanical advantages translate to a lower rate of pin replacement prior to healing. The research question posed was "Is there sufficient evidence to prove that hydroxyapatite coating lowers the rate of pin replacement for external fixation?", Methods: An electronic search of Medline (Ovid, 1946 - December Week 4 2011), Embase (Ovid, 1980-2011 Week 52), and the Cochrane Central Register of Controlled Trials (Issue 4 of 4, October 2011) was conducted to identify all randomized and quasi-randomized controlled trials which compared HA-coated pins with non-coated pins for external fixation, with particular emphasis on the premature replacement of pins as a consequence of loosening., Results: The combined search strategies retrieved 72 citations. Four randomized controlled trials (101 patients, 327 HA-coated vs. 354 uncoated pins) were included in this review. None of the studies demonstrated a clear benefit between pin types with respect to premature replacement of pins prior to healing., Conclusion: This review did not find sufficient evidence to validate the preferential use of HA-coated pins over standard pins as a means of avoiding premature replacement of pins used for external fixation. The use of uncoated pins is justifiable, especially within the context of limited financial resources.

Preclinical evaluation of spinal implants is a necessary step to ensure their reliability and safety before implantation. The American Society for Testing and Materials reapproved F1717 standard for the assessment of mechanical properties of posterior spinal fixators, which simulates a vertebrectomy model and recommends mimicking vertebral bodies using polyethylene blocks. This set-up should represent the clinical use, but available data in the literature are few. Anatomical parameters depending on the spinal level were compared to published data or measurements on biplanar stereoradiography on 13 patients. Other mechanical variables, describing implant design were considered, and all parameters were investigated using a numerical parametric finite element model. Stress values were calculated by considering either the combination of the average values for each parameter or their worst-case combination depending on the spinal level. The standard set-up represents quite well the anatomy of an instrumented average thoracolumbar segment. The stress on the pedicular screw is significantly influenced by the lever arm of the applied load, the unsupported screw length, the position of the centre of rotation of the functional spine unit and the pedicular inclination with respect to the sagittal plane. The worst-case combination of parameters demonstrates that devices implanted below T5 could potentially undergo higher stresses than those described in the standard suggestions (maximum increase of 22.2% at L1). We propose to revise F1717 in order to describe the anatomical worst case condition we found at L1 level: this will guarantee higher safety of the implant for a wider population of patients., (© IMechE 2014.)

Tibia fractures in children are generally treated successfully by conservative means. The aim of this study was to evaluate the efficacy and safety of fixation using Titanium elastic nails (TEN) in pediatric tibia fractures in which conservative measures failed or were deemed inapplicable. In this study, 30 patients who had tibia fractures and were fixated with TEN between 2007 and 2011 were analyzed retrospectively. The procedure was performed after poly-trauma in six patients, open fracture in seven, reduction loss in twelve, and unsuccessful closed reduction in five patients. The number of girls and boys was 3 and 27, respectively, with a mean age of 9.8 years. The evaluation criteria of Flynn et al. were used in the analysis of the results. The mean follow-up period was 18 months. The mean period of union was 8 weeks and 14 weeks in closed and open fractures, respectively. Epiphyseal damage, rotational deformity, need for reintervention, deep infection, implant failure, or recurrent fracture was not observed in any case. According to the Flynn evaluation system, 23 cases were evaluated as excellent, and 7 as good. Fixation with TEN is an easy, effective, and safe method that can be used in tibia fractures that are open, irreducible, or with loss of reduction and in cases with accompanying trauma, such as floating knee.

Despite poor early results with intramedullary nailing of extra-articular proximal tibia fractures, improvements in surgical technique and implant design modifications have resulted in more acceptable outcomes. However, prevention of the commonly encountered apex anterior and/or valgus deformities remains a challenge when treating these injuries. It is necessary for the surgeon to recognize this and know how to neutralize these forces. Surgeons should be comfortable using a variety of the reduction techniques presented to minimize fracture malalignment., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Object: Halo orthosis placement is a common neurosurgical procedure for the treatment of cervical spine injuries. Frontal sinus puncture by the anterior pins may occur using standard techniques, and up to 30% are dissatisfied with forehead scarring, especially women and African Americans., Methods: The authors describe a frontolateral (FL) anterior pin site placement supported by high-resolution CT scan skull thickness measurements. The standard supraorbital (SO) pin site is several centimeters above the lateral orbit, whereas the FL pin site is 2-3 cm posterolateral to the SO site. Frontolateral placement is just anterior to the temporalis muscle close to a triangular anterior projection of the temporal hairline. For quantitative information on skull thickness at the SO and FT pin sites, thin 0.625-mm CT scan measurements of the outer table, diploic space, and inner table were obtained in 40 adults (80 sites)., Results: The mean values for total skull thickness at the SO and FT sites were not significantly different. The inner table was significantly thicker at the FL site in both males and females, buttressed by the nearby greater sphenoid wing. The mean total skull thickness was significantly less in females than in males, but the values were not significantly different at the SO and FL sites., Conclusions: The FL and SO anterior pin sites are comparable with respect to skull thickness CT measurements, with a significantly thicker inner table at the FL site. In the senior author's experience, the FL anterior pin site yielded secure fixation without skull perforation, neurovascular injury, or propensity to infection. The cosmetic result of the FL site is more acceptable, and the authors recommend its general usage be adopted.

Object: Cobalt-chromium alloy (CoCr) rods haves some preferred biomechanical properties over titanium rods for spinal fixation. The use of CoCr rods in spinal fusion is relatively new, and there is no study in the existing world literature assessing the artifact caused by these rods in patients undergoing postoperative MRI. The purpose of this study is to compare the amount of imaging artifact caused by these implants and to assess its impact on the visualization of neighboring neural structures., Methods: This study investigated MR images in patients who underwent implantation of thoracolumbar instrumentation using 5.5-mm-diameter CoCr rods between November 2009 and March 2011 and images obtained in a comparison group of patients who had 5.5-mm titanium rods implanted during the same time period. Axial measurements of the artifact created by the rods between the screw heads were compared between the groups. Two blinded board-certified radiologists performed the measurements independently. They scored the visualization of the spinal canal using a subjective scoring system of 1-3, with 1 representing very good visualization and 2 and 3 representing reduced (good or suboptimal, respectively) visualization as a result of rod-related artifact. All measurements and scores were independently provided for T1-weighted and T2-weighted fast spin echo sequences (1.5-T magnet, 5-mm slice thickness)., Results: A total of 40 levels from the CoCr group (6 patients) and 30 levels from the titanium group (9 patients) were included in the analysis. Visualization of the canal at all levels was rated a score of 1 (very good) by both evaluators for both the CoCr and titanium groups. The average artifact on T1-weighted images measured 11.8 ± 1.8 mm for the CoCr group and 8.5 ± 1.2 mm for the titanium group (p < 0.01). The corresponding measurements on T2-weighted images were 11.0 ± 2.3 mm and 8.3 ± 1.7 mm (p < 0.01), respectively. In a mixed regression model, the mean artifact measurement for the CoCr group was, on average, 3.5 mm larger than for the control group. There was no significant difference between the measurements of the 2 evaluators (p = 0.99)., Conclusions: The artifact caused by CoCr rods is approximately 3.5 mm larger than that caused by titanium rods on axial T1- and T2-weighted MRI. However, artifact from either CoCr or titanium was not found to interfere with the evaluation of the spinal canal and surrounding neural elements.

The authors report a case of progressive congenital kyphoscoliosis in which the patient, a boy, originally underwent combined anterior and instrumented posterior spinal fusion at the age of 7 years and 3 months. Early proximal junctional kyphosis and implant failure mandated proximal extension of implants with 2 new rods connected to the old caudad short rods. At the 3-year follow-up, clinical and CT assessment revealed a thoracolumbar pseudarthrosis for which the patient underwent a 2-stage procedure without complication. Recordings of somatosensory evoked potentials intraoperatively were normal. Twelve hours after surgery, his neurological status started to progressively deteriorate. The patient was brought to the operating room, and the initially achieved correction was reversed by an apex-only exposure of the 4-rod system. After surgery the patient started to show progressive improvement in his neurological function. A final myelography was performed and showed free passage of the dye without evidence of obstruction. Clinically, the patient continued to improve and at his 3-month follow-up had near-complete resolution of his neurological deficits. Findings on his physical examination were normal at the final 12-year follow-up. Despite normal findings on intraoperative neuromonitoring, a delayed neurological deficit can occur after complex spine reconstruction. Preoperative risk assessment, surgical approach, and instrumentation deserve careful attention. Advantages of a 4-rod construct are discussed in this case.

Purpose: The aim of this study was to compare two intramedullary devices used in the treatment of intertrochanteric fractures., Method: During the period 2006-2007 46 TGN and 51 PFNA were used for the treatment of intertrochanteric fractures in our hospital. Clinical and radiological follow-up were available. Surgical time, blood loss and complications have been considered., Results: The mean operative time for the TGN group was significantly higher than in the PFNA group (62 min and 45 min, respectively) with a p = 0.04. The mean blood loss was significantly higher in the TGN group (285 ml; SD 145) in relation to the PFNA group (226 ml; SD 136) with p = 0.03. Also, rate of complications was higher in the TGN group (p = 0.01). Clinical outcomes were good for both groups. Intra-operative and post-operative complications in the TGN group were associated with a longer operative time and a higher blood loss, probably due to the reaming needed in TGN that can increase blood loss and risk of comminution or fracture propagation. Moreover, all but one of the procedure-related complications were observed in very elderly patients., Conclusions: Based on our results in the intertrochanteric fracture, use of PFNA should be recommended in cases of elderly and osteoporotic patients, while TGN should be used in more severely displaced fractures in patients with a slightly better bone mineral density.

Background: Intramedullary nailing of pertrochanteric femoral fractures has grown in popularity over the past 2 decades likely because this procedure is associated with a low risk for postoperative morbidity and a fast recovery of function. The evaluation of outcomes associated with pertrochanteric nailing has mainly been based on objective measures. The purpose of the present study is to correlate patients' health-related quality of life results after intramedullary nailing of pertrochanteric fractures with objective outcome measures., Methods: We conducted a single-center study including 62 patients (mean age 80 ± 10 years) with pertrochanteric fractures treated with a Gamma 3 Nail. Health related quality of life was measured using the Short Form-36. These results were compared to both US and Austrian age and sex-adjusted population norms. The objective outcome measures studied at one year postoperatively included Harris Hip Score, range of motion, leg length, body mass index, neck-shaft angle and grade of osteoarthritis., Results: According to the Harris Hip Score 43 patients (67%) had excellent or good results. There was no significant difference in the average neck-shaft angle comparing affected hip to non-affected hip at 12 months postoperatively. The average osteoarthritis score, for both the injured and uninjured hip, did not differ significantly. We found significant differences between the bodily pain, social functioning and mental health subscales and two summary scores of the Short-Form 36 in comparison to Austrian population norms. Complication rate was 8%., Conclusions: The results of this study confirm that intramedullary nailing with the use of a Gamma Nail is a safe treatment option for stable and unstable pertrochanteric fractures. Despite good functional and radiographic results we noticed a substantial fall off in patients' quality of life up to 12 months after operation.

Objective: Iliac crest autograft remains the gold standard for spinal fusion operations. Given risk of donor site morbidity, many centers utilize allograft. We reviewed published series of C1-2 posterolateral instrumented fusions with allograft and autograft., Methods: Online databases were searched for English-language articles reporting quantifiable outcome data published between 1994 and 2011 of posterior atlantoaxial instrumented arthrodesis with C1 and C2 screws. Thirteen studies describing 652 patients having autograft and seven studies describing 60 patients having allograft serve as the basis of this report., Results: All studies were retrospective case series (Class III evidence). There were no differences in complications or mortality between the groups. There were trends toward shorter operative times and less blood loss using allograft. A higher proportion of patients in the allograft group underwent sacrifice of the C2 nerve root and decortication and packing of the C1-2 joints (P<0.0001). There was no significant difference in the proportion of surviving patients who achieved solid fusion in the autograft (642 of 644 [99.7%]) and allograft patients (59 of 59 [100%]; P = 1.0)., Conclusions: This review is limited by the retrospective data and inconsistent methodology of fusion determination used in most studies. Modern instrumentation and proper surgical techniques result in high rates of successful C1-2 arthrodesis. The use of allograft is a treatment option (Class III evidence) during posterior C1-2 instrumentation and fusion operations. Randomized, controlled trials using standardized radiographic assessments are needed across spinal arthrodesis studies to better determine the prevalence of radiographic fusion and establish technique superiority., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: The surgical treatment of fractures of the tibia includes reamed and unreamed options. Reamed nails have mechanical advantages but they significantly harm the endosteal circulation. Unreamed nails spare the endosteal circulation, but provide a less stable fixation. In both systems, immediate full weight-bearing is not possible due to instability related to distal interlocking (DI). Further, DI is responsible for the majority of the fluoroscopy requirement and a significant loss of surgical time. In our study, we present the clinical results of a new intramedullary (IM) nail and system, which allows stable fixation with an unreamed technique that permits immediate full weight-bearing, with a minimum fluoroscopy requirement for DI., Methods: Fifty tibia fractures (49 patients) operated using our new IM system between 2008 and 2010 were evaluated retrospectively. They were allowed full weight-bearing the day after surgery. The patients were followed at least 10 months postoperatively., Results: Mean fluoroscopy time was 18 seconds (min: 10, max: 30) for DI. Mean union time was 9 weeks (min: 6, max: 12). There was no neurovascular injury, deep infection, malunion, delayed union, or nonunion., Conclusion: We demonstrated that our newly developed IM nail and new DI system may be an option to solve the stability problems sourced from the DI screw. It also significantly decreases the requirement of fluoroscopy.

Very little is known about the influence of the mechanical environment on the healing of large segmental defects. This partly reflects the lack of standardised, well characterised technologies to enable such studies. Here we report the design, construction and characterisation of a novel external fixator for use in conjunction with rat femoral defects. This device not only imposes a predetermined axial stiffness on the lesion, but also enables the stiffness to be changed during the healing process. The main frame of the fixator consists of polyethylethylketone with titanium alloy mounting pins. The stiffness of the fixator is determined by interchangeable connection elements of different thicknesses. Fixators were shown to stabilise 5 mm femoral defects in rats in vivo for at least 8 weeks during unrestricted cage activity. No distortion or infections, including pin infections, were noted. The healing process was simulated in vitro by inserting into a 5 mm femoral defect, materials whose Young's moduli approximated those of the different tissues present in regenerating bone. These studies confirmed that, although the external fixator is the major determinant of axial stiffness during the early phase of healing, the regenerate within the lesion subsequently dominates this property. There is much clinical interest in altering the mechanics of the defect to enhance bone healing. Our data suggest that, if alteration of the mechanical environment is to be used to modulate the healing of large segmental defects, this needs to be performed before the tissue properties become dominant.

Due to the annular gap between intramedullary (IM) nails and the endosteal surface, high interfragmentary movement can occur under loading. This could prolong the healing time, particularly for thin IM nails that are often used for unreamed IM nailing. The aims of our study were to determine the influence of the nail diameter on the healing time of human tibial shaft fractures and to investigate whether the healing time could be shortened by increasing the stiffness of the implant material. Therefore, a corroborated numerical model for simulating the fracture healing process in humans was used to simulate the healing process of human tibial fractures treated with IM nails. The calculated healing time (up to 71 weeks) was longest for transverse fractures treated with thin IM nails made of titanium. That the healing time was disproportionately long depended on the nail diameter, and could be greatly reduced by using a thicker nail or using steel instead of titanium. To avoid a prolonged healing time, the nail should be thick, and the annular gap should be as narrow as possible. Alternatively, using steel instead of titanium may also help to avoid a prolonged healing time., (Copyright © 2011 Orthopaedic Research Society.)

Purpose: Restoration of the anterior spinal profile and regular load-bearing is the main goal treating anterior spinal defects in case of fracture. Over the past years, development and clinical usage of cages for vertebral body replacement have increased rapidly. For an enhanced stabilization of rotationally unstable fractures, additional antero-lateral implants are common. The purpose of this study was the evaluation of the biomechanical behaviour of a recently modified, in situ distractible vertebral body replacement (VBR) combined with a newly developed antero-lateral polyaxial plate and/or pedicle screws and rods using a full corpectomy model as fracture simulation., Methods: Twelve human spinal specimens (Th12-L4) were tested in a six-degree-of-freedom spine tester applying pure moments of 7.5 Nm to evaluate the stiffness of three different test instrumentations using a total corpectomy L2 model: (1) VBR+antero-lateral plate; (2) VBR, antero-lateral plate+pedicle screws and rods and (3) VBR+pedicle screws and rods., Results: In the presented total corpectomy defect model, only the combined antero-posterior instrumentation (VBR, antero-lateral plate+pedicle screws and rods) could achieve higher stiffness in all three-movement planes than the intact specimen. In axial rotation, neither isolated anterior instrumentation (VBR+antero-lateral plate) nor isolated posterior instrumentation (VBR+pedicle screws and rods) could stabilize the total corpectomy compared to the intact state., Conclusions: For rotationally unstable vertebral body fractures, only combined antero-posterior instrumentation could significantly decrease the range of motion (ROM) in all motion planes compared to the intact state.

Study Design: Retrospective analysis of a consecutive cohort of 62 adolescent patients treated by posterior spinal fusion (PSF) with a minimum follow-up of 2 years., Objective: To present sagittal and coronal results of a specific method of reduction: the simultaneous translation on 2 rods (ST2R)., Summary of Background Data: The long-term outcome of surgically treated scoliosis is dependent not only on the coronal correction but also on restoration of sagittal curves. Recent publications confirm the moderate correction of thoracic hypokyphosis by posterior instrumentation with hooks or pedicle screws., Methods: Radiographic parameters were measured preoperatively and at 6 weeks, 1 year, and last follow-up (between 2 and 7.4 years) in a consecutive cohort of 62 patients with adolescent idiopathic scoliosis (AIS) treated by PSF. All operative procedures were performed by the same surgeon using stable anchorages such as screws or self-stabilizing claws. The screws and claws included a polyaxial-threaded extension, which was fixed to the rod with connecting clamps. Reduction of the deformity was obtained by gradual and alternate tightening of the nuts on all threaded extensions on both rods, which allowed the vertebrae to gradually approach the rods while the translation maneuver was performed., Results: In the coronal plane, the average main curve was reduced from 51° to 16° and maintained 70% of correction at last follow-up. In the sagittal plane, for patients with hypokyphosis (27 cases < 20°), the average kyphosis angle was significantly improved from 9° to 29° and maintained during follow-up (32°) with a mean gain of 23° (P < 0.0001). Only 1 patient reported hypokyphosis (18°) at last follow-up. For patients with normal kyphosis, the average gain was 8°., Conclusion: In a large consecutive cohort, reduction of scoliosis by ST2R is a simple method that allows 70% of correction in the coronal plane, equivalent to screw instrumentations, and a restoration of normal thoracic kyphosis.

Introduction: Various techniques have been described for posterior atlantoaxial fusion. Sublaminar passage of the wire/cable is cumbersome with a risk of spinal cord injury. Packing morselized bone grafts into the C1-2 facet joints may be difficult and it may cause massive bleeding and neuropathic pain or posterior scalp numbness postoperatively. We introduce a modified method by using C1-2 screw-rod fixation (SRF) to compress a structural iliac bone graft between the posterior elements of C1 and C2 without supplemental wiring construct., Materials and Methods: From December 2006 to May 2009, 35 consecutive patients with atlantoaxial instability treated by this method were reviewed retrospectively. Clinical and radiographic history was recorded. Patients with neck pain had relieved significantly after surgery and the neurologic status was also improved greatly. Thirty-three (94.3%) patients gained bony fusion at 3 months postoperatively. No vertebral artery and spinal cord injuries were noted. There was no instrumentation failure during the observation period., Conclusion: We conclude that the C1-2 SRF with construct-compression structural bone grafting can be used for C1-2 fusion with relatively simple performance and less time-consuming in selected cases.

Background: A weight-bearing platform applied at the distal end of an Ilizarov external frame allows patients with hindfoot transfixations, foot deformities or plantar skin lesions to bear weight. This leads to an indirect loading of the fracture or osteotomy site. However, the effect on the fracture/osteotomy site's motion or compressive loads is unknown. The aim of this study was to analyze the mechanical effects of a weight-bearing platform on the traditional all-wire, four-ring frame in comparison to a two-ring frame consisting of half-pins., Methods: Two frame configurations, with either anatomically positioned wires or half-pins, were analyzed with and without a weight-bearing platform applied underneath the distal ring. Composite tibiae with a mid-diaphyseal osteotomy of 3.5 mm were used in all the experiments. An axial load was applied with the use of a universal test machine (UTS®). Interfragmentary movements, the relative movements of bone fragments and movements between rings were recorded using displacement transducers. Compressive loads at the osteotomy site were recorded with loading cells., Results: Indirect loading with a weight-bearing platform altered the force transmission through the osteotomy. Indirect loading of the tibiae decreased the extent of the axial micro-motion by 50% under the applied weight load when compared to direct weight loading (p < 0.05). The half pin frame was 25% stiffer than the wire frame under both direct and indirect loading of the tibiae (p < 0.05). Compressive loads under indirect loading were reduced by 67% in the wire frame and by 57% in the half-pin frames compared to direct loading of the bones (p < 0.05). While axial loading in the wire frames resulted in plain axial movements at the site of the osteotomy, it was coupled with translational movements and angular displacements in the half pin mountings. This effect was more apparent in the case of indirect loading., Conclusions: A weight-bearing platform has substantial influence on the biomechanical performance of an Ilizarov external fixator. Half-pins induce greater stiffness to the Ilizarov external fixator and allow the usage of only one ring per bone segment, but shear stresses at the osteotomy under axial loading should be considered. The results allow an estimation of the size and direction of interfragmentary movements based on the extent of weight bearing.

Study Design: Review of a prospectively collected growing rod database., Objective: To define risk factors for and characterize the nature of growing rod fractures., Summary of Background Data: Rod fracture is a common complication of growing rod treatment. The project sought to analyze risk factors for rod breakage and develop preventive strategies., Methods: Records of 327 patients in a prospectively collected growing rod database were studied. Risk factors studied were studied as patient-related and rod-related. Multivariate analysis was performed., Results: Eighty-six rod fractures occurred in 49 patients (49 of 327, 15%). Sixteen patients had repeat fractures with eight patients having more than two fractures (maximum six). The most common fracture locations were above or below the tandem connectors (34 of 86) and near the thoracolumbar junction (35 of 86). Other locations were adjacent to anchors (12 of 86) and cross-links (2 of 86). Syndromic diagnoses had the highest rate of fracture; significantly greater than neuromuscular diagnoses (14% vs. 2%, P = 0.01). Patients who were ambulatory had a higher fracture rate (21% vs. 8.7%, P = 0.01). Single rods had a higher fracture rate than dual rods (36% vs. 11%, P < 0.001). Repeat fracture was also more common in patients with single rods (13% vs. 2%, P = 0.0002). In dual-rod constructs, the incidence of both rods breaking at the same time was 26% (7 of 27). Stainless steel rods had a higher fracture rate than titanium rods (29% vs. 18%, P = 0.02). The nonfracture group had larger diameter rods than the fracture group (P = 0.01). The fracture group had shorter tandem connectors than the nonfracture group (P < 0.001). Neither the size of preoperative scoliosis (P = 0.2) nor kyphosis (P = 0.4) was a risk factor for fracture. Length of instrumentation (P = 0.9), anchor type (P = 0.6), and pelvic fixation (P = 0.38) had no significant effect on fracture rates. Eight wound complications were reported, including three cases of skin breakdown at the rod fracture site., Conclusion: Risk factors for rod fractures include prior fracture, single rods, stainless steel rods, small diameter rods, proximity to tandem connectors, short tandem connectors, and preoperative ambulation. Repeat fractures are common, especially with single rods. Rod replacement, with larger diameter rods if appropriate, may be a preferred strategy over connecting the broken rods as fractures signal fatigue of the rod.

Sixty-two femoral shaft fractures in 60 patients treated by elastic intramedullary nailing with mean age of the patients being 9.2 years (range 5 years to 12 years) and average follow-up of 15 months (range 7 months to 60 months) are evaluated. Twenty-eight fractures were fixed with titanium elastic nail while 34 fractures were fixed with Enders nail. There were 40 midshaft fractures, 18 proximal femoral and 4 were fractures of distal third. Fracture patterns were transverse in 35, short oblique in 14 cases and 13 were spiral fractures. Mean age of union in this series was 17 weeks (range 12 weeks to 28 weeks). Ten cases had complications, 5 had nail tip irritation, 3 varus or valgus malalignment and 2 had delayed union. In this series, we did not have any non-union, refracture, limb length discrepancy or any major infection. The result demonstrates 100% union rate irrespective of the age, weight and height of the patient. Regardless of the site of fracture and their pattern, it united every time with elastic nail fixation. We did not find and mismatch in the results of fractures stabilised with titanium elastic nail with that of elastic stainless steel nail.

Introduction: Recently, results from the large, randomized study to prospectively evaluate reamed intramedullary nails in patients with tibial fractures (SPRINT) trial suggested a benefit for reamed intramedullary nail insertion in patients with closed tibial shaft fractures largely based on cost-neutral autodynamizations and a potential advantage for unreamed intramedullary nailing in open fractures. We performed an economic evaluation to compare resource use and effectiveness of reamed and unreamed intramedullary nailing using a cost-utility analysis., Methods: We calculated quality-adjusted life years (QALYs) for each patient from a self-administered health utility index 3 questionnaire for the first 12 months following the intramedullary nailing. A convenience sample of 235 SPRINT patients provided data on costs associated with health care resource utilization. All costs are reported in Canadian dollars for the 2008 financial year., Results: We found incremental effects of -0.017 (95% confidence interval [CI] -0.021-0.058) and -0.002 (95% CI -0.060-0.062) QALYs for patients treated with reamed compared with unreamed intramedullary nails in closed and open fractures, respectively. The incremental costs for reamed compared with unreamed intramedullary nailing were $51 Canadian dollars (95% CI -$2298-$2400) in closed tibial fractures and $2546 Canadian dollars (95%CI -$1773-$6864) in open tibial fractures. Unreamed nailing dominated reamed nailing for both closed and open tibial fractures; however, the cost and the utility results had high variability., Conclusion: Our economic analysis from a governmental perspective suggests small differences in both cost and effectiveness with large uncertainty between reamed and unreamed intramedullary nailing., (Copyright © 2011 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)