Selection of internal fixation method for femoral intertrochanteric fractures using a finite element method

BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimensional model of the femur was established from sectional computed tomography images,and an internal fixation model was established.Finite element analysis of the femur model was established,and three intertrochanteric fracture models,medial defect,lateral defect,and medial-lateral defects,were simulated.Displacement and stress distribution after fixation with a proximal femoral anti-rotation intramedullary nail(PFNA),integrated dual-screw fixation(ITN),PFNA+wire,PFNA+plate,and PFNA+wire+plate were compared during daily activities.RESULTS The maximum displacement and stress of PFNA and ITN were 3.51 mm/473 MPa and 2.80 mm/588 MPa for medial defects;2.55 mm/288 MPa and 2.10 mm/307 MPa for lateral defects;and 3.84 mm/653 MPa and 3.44 mm/641 MPa for mediallateral defects,respectively.For medial-lateral defects,reconstructing the medial side alone changed the maximum displacement and stress to 2.79 mm/515 MPa;reconstructing the lateral side changed them to 3.72 mm/608 MPa,when both sides were reconstructed,they changed to 2.42 mm/309 MPa.CONCLUSION For medial defects,intramedullary fixation would allow early low-intensity rehabilitation exercise,and ITN rather than PFNA reduces the risk of varus and cut-out;for lateral wall defects or weakness,intram-edullary fixation allows higher-intensity rehabilitation exercise,and ITN reduces the risk of varus.For both medial and lateral defects,intramedullary fixation alone will not allow early functional exercise,but locating lateral or medial reconstruction will.For defects in both the inner and outer sides,if reconstruction cannot be completed,ITN is more stable.

A segmental defect adaptation of the mouse closed femur fracture model for the analysis of severely impaired bone healing

Objective: To better characterize nonunion endochondral bone healing and evaluate novel therapeutic approaches for critical size defect healing in clinically challenging bone repair, a segmental defect model of bone injury was adapted from the threepoint bending closed fracture technique in the murine femur.Methods: The mouse femur was surgically stabilized with an intramedullary threaded rod with plastic spacers and the defect adjusted to different sizes. Healing of the different defects was analyzed by radiology and histology to 8 weeks postsurgery. To determine whether this model was effective for evaluating the benefits of molecular therapy, BMP-2 was applied to the defect and healing then examined.Results: Intramedullary spacers were effective in maintaining the defect. Callus bone formation was initiated but was arrested at defect sizes of 2.5 mm and above, with no more progress in callus bone development evident to 8 weeks healing. Cartilage development in a critical size defect attenuated very early in healing without bone development, in contrast to the closed femur fracture healing, where callus cartilage was replaced by bone. BMP-2 therapy promoted osteogenesis of the resident cells of the defect, but there was no further callus development to indicate that healing to pre-surgery bone structure was successful.Conclusions: This segmental defect adaptation of the closed femur fracture model of murine bone repair severely impairs callus development and bone healing, reflecting a challenging bone injury. It is adjustable and can be compared to the closed fracture model to ascertain healing deficiencies and the efficacy of therapeutic approaches.

Intramedullary nailing of clavicular midshaft fractures in adults using titanium elastic nail

Objective： Studies showed elastic stable intramedullary nailing （ESIN） of displaced midclavicular fractures has excellent outcomes, as well as high complication rates and specific problems. The aim was to discuss ESIN of midshaft clavicular fractures.Methods： Totally 60 eligible patients （aged 18-63 years） were randomized to either ESIN group or non-operative group between January 2007 and May 2008. Clavicular shortening was measured after trauma and osseous consolidation.Radiographic union and complications were assessed. Function analysis including Constant shoulder scores and disabilities of the arm, shoulder and hand （DASH） scores were performed after a 15-month follow-up.Results： ESIN led to a signifcantly shorter time to union, especially for simple fractures. In ESIN group, all patients got fracture union, of which 5 cases had medial skin irritation and 1 patient needed revision surgery because of implant failure. In the nonoperative group, there were 3 nonunion cases and 2 symptomatic malunions developed requiring corrective osteotomy. At 15 months after intramedullary stabilization, patients in the ESIN group were more satisfied with the appearance of the shoulder and overall outcome, and they benefited a lot from the great improvement of post-traumatic clavicular shortening. Furthermore,DASH scores were lower and Constant scores were significantly higher in contrast to the non-operative group.Conclusion： ESIN is a safe minimally invasive surgical technique with lower complication rate, faster return to daily activities, excellent cosmetic and better functional results,restoration of clavicular length for treating mid-shaft clavicular fractures, resulting in high overall satisfaction, which can be regard as an alternative to plate fixation or nonoperative treatment of mid-shaft clavicular fractures.

Comparative study on treatment of midshaft tibial fracture with expandable and interlocking intramedullary nails

Objective ： To evaluate the clinical results of treatment of midshaft tibial fracture with expandable intramedullary nails compared with interlocking intramednilary nails. Methods： From June 2003 to August 2005, 46 patients （27 males and 19 females, aged 20-74 years, mean =38.4 years ） with midshaft tibial fracture were treated surgically in our department. The causes of fractures were traffic injury in 21 patients, fall injury in 6, tumbling injury in 11 and crushing injury in 8. According to AO/ ASIF classification, Type A fracture was found in 16 patients, Type B in 11, Type C1 in 5, and Type C2 in 2. Open fractures were found in 12 patients, according to Gustilo classification, Type Ⅰ in 9 patients and Type Ⅱin 3 patients. Based on the patients＇consent, 24 patients were treated with expandable intramedullary nails （Group A ） and 22 with interlocking intramedullary nails （Group B ）. The operation time, blood loss during operation, X-ray fluoroscopic times, hospitalization time, weight bearing time after operation, healing time of fracture and complications of all the patients were recorded. The clinical effects of all the cases were evaluated according to the criteria of Johner-Wruhs. Results： All the patients were followed up for 12,34 months （ mean = 16.2 months）. The time of operation, the blood loss, X-ray fluoroscopic times, hospitalization time and healing time of fracture of Group A significantly decreased （P 〈 0.05 ） compared with those of Group B, but the time for weight bearing after operation, the Johner- Wruhs degree of clinical effects and complications had no significant difference between Group A and Group B （P〉0.05）. Conclusions： Expandable intramedullary nail can shorten operation time, decrease blood loss and reduce invasion, which is a safe and effective treatment method for tibial midshaft fracture.

Treatment of nonunions of humeral fractures with interlocking intramedullary nailing

Objective： To introduce the experience of treating nonunions of humeral fractures with interlocking intramedullary nailing. Methods： Twelve patients with humeral nonunions were treated with interlocking intramedullary nailing. The time interval between trauma and surgery was 10.5 months on average. Open reduction with anterograde approach was performed. Axial compression was specially applied to the fracture site with humeral nail holder after insertion of distal locked screws. Iliac bone grafting was added. Results： The average follow-up period was 21 months （ranging 9-51 months）. All patients achieved osseous union 5.8 months after treatment on average. Eleven patients hadgood functions of the shoulder joints and the upper extremities. No patient experienced any permanent neurological deficit. Refracture of the original ununited region occurred in one patient after removal of the internal fixator one year later, but union was achieved after closed re-intramedullary nailing fixation. Conclusion： Humeral interlocking intramedullary nailing is an effective alternative treatment for humeral nonunion.

Elastic intramedullary nail for treatment of extremity fractures in children

Objective： To assess the clinical therapeutic effects of elastic intramedullary nail on extremity fractures in children. Methods： From June 2005 to March 2008, 40 children with extremity fractures were treated by elastic intramedullary nail, in whom femoral shaft fractures occurred in 26 cases, tibiofibular fractures in 8 cases, radial capitular fractures in 4 cases, ulnoradial fractures in 2 cases. All patients were treated by closed reduction and elastic intramedullary nail fixation. Results： All the fractures gained satisfactory reduction and healing. The average duration needed for fracturehealing was 1-2 months. Postoperative follow-up confirmed a sound functional recovery. Conclusions： The elastic intramedullary nail is a minimally invasive and effective surgical approach for treatment of extremity fractures in children. It allows early functional exercises after operation and secures a satisfactory bone union and functional recovery.

Reamed or unreamed intramedullary nailing for tibial fractures： a meta-analysis

Objective：To compare the treating effects of different intramedullary nailing methods on tibial fractures in adults.Methods：Literature reports in both Chinese and English languages were retrieved （from the earliest available records to October 1,2013） from the PubMed,FMJS,CNKI,Wanfang Data using randomized controlled trials （RCTs） to compare reamed and unreamed intramedullary nailing for treatment of tibial fractures.Methodological quality of the trials was critically assessed,and relevant data were extracted.Statistical software Revman 5.0 was used for data-analysis.Results：A total of 12 randomized controlled trials,comprising 985 patients （475 in the unreamed group and 510 in the reamed group）,were eligible for inclusion in this meta-analysis.The results of metaanalysis showed that there were no statistically significant differences between the two methods in the reported outcomes of infection （RR=0.64; 95％CI,0.39 to 1.07;P=0.09）,compartment syndrome （RR=1.44; 95％CI,0.8to 2.41; P=0.16）,thrombosis （RR=1.29; 95％CI,0.43to 3.87; P=0.64）,time to union （WMD=5.01; 95％CI,-1.78 to 11.80; P=0.15）,delayed union （nonunion）（RR=1.56; 95％CI,0.97 to 2.49; P=0.06）,malunion （RR=1.75; 95％CI,1.00 to 3.08; P=0.05） and knee pain （RR=0.94; 95％CI,0.73 to 1.22; P=0.66）.But there was a significantly higher fixation failure rate in the unreamed group than in the reamed group （RR=4.29; 95％CI,2.58to 7.14; P＜0.00001）.Conclusion：There is no significant difference in the reamed and unreamed intramedullary nailing for the treatment of tibial fractures,but our result recommends reamed nails for the treatment of closed tibial fractures for their lower fixation failure rate.

Computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails: a preliminary report on clinical application

Objective： To evaluate the clinical feasibility and effect of the computer-assisted auto-frame navigation system for distal locking of tibial intramedullary nails. Methods： The hardware components of the system included a PC computer with a monitor, auto mechanical stereotactical locating cubic frame, foot holder and localization operative apparatus. Special navigation software can be used for registration of X-ray fluoroscopic images and real-time controlling navigation of tools. Twenty-one cases of dose tibial and fibular fractures were treated with dosed intramedullary nailing, 6 of which involved in middle third, 12 in middle and lower third, 3 in lower third. C-arm alignment and registration time, fluoroscopic time and drilling time involved in the locking procedure were recorded. The size of unreamed or reamed tibial nails ranged from 8/300-11/330. Results： All distal holes except 1 were locked successfully. In 9 of 41 locked holes （21.95 % ）, the drill bit touched the canal of locking hole without damage of the nail and clinical consequences. The fluoroscopy time per pair of screws was 2.23 s± 0.31s. Conclusions： The computer-assisted auto-frame navigation system for distal locking is well designed, easy to operate and do not need additional instrmnents during the procedure. The developed system enables the physician to precisely navigate surgical instruments throughout the anatomy using just a few computer-calibrated radiographic images. The total time of x-ray exposure per procedure can be significantly reduced.

To evaluate the role of platelet-rich plasma in healing of acute diaphyseal fractures of the femur

Purpose： New research is focusing on the use of autologous growth factors to increase the effect of bone fracture healing while decreasing the amount of healing time for the patient. Platelets have been demonstrated to be the natural storage vessel for several growth factors and cytokines that promote blood coagulation, tissue repair, and the process of bone mineralization. The present study aims to evaluate the role of platelet-rich plasma （PRP） in healing of acute femoral shaft fractures radiologically. We hypothesize that it provides artificial hematoma and releases various growth factors. Methods： This prospective randomized study was carried out in 72 patients of traumatic fracture of the femoral shaft operated with interlocking nails （closed or open）. Patients were divided into two groups： study group A （n - 33） treated with intramedullary nailing ＆ PRP injection/gel application in the same setting; and control group B （n - 39） treated with intramedullary nailing without PRP application. Both groups were further divided into two subgroups. Study group included subgroup AI （n = 14） operated with closed intTamedullary nailing and PRP injection at the fracture site under radiological control, and subgroup A2 （n = 19） operated with open intramedullary nailing and PRP gel along with fibrin membrane application at the fracture site; while control group included subgroup B1 （n - 16） operated with closed intramedullary nailing, and subgroup B2 （n -- 23） operated with open intramedullary nailing. Radiological assessment of fracture healing was done by measuring the cortex to callus ratio every month till union at 6 months. Results： Measurements of mean cortex to callus ratio revealed significant difference between the groups A ＆ B at third and fourth months. Measurements of mean cortex to callus ratio did not reveal significant difference between the subgroups at first and sixth months. A statistically significant difference was observed between subgroups A1 ＆ B2 and B1 ＆ B2 at the second month; between subgroups A1 ＆ B2, A2 ＆ B2 and BI ＆ B2 at the third month; and between subgroups A1 ＆ B2 at fourth and fifth months. Conclusion： PRP has no effect on femoral shaft fracture healing treated with closed intramedullary nailing. However, PRP and matrix scaffold provided by fibrin membrane may provide an artificial he- matoma effect in the initial phase of healing in open or failed closed intramedullarv nailing.

Orthopaedic surgeon＇s nightmare： iatrogenic fractures of talus and medial malleolus following tibial nailing

Intramedullary interlocking nailing is the gold standard for treatment of tibial shaft fractures. The growing use of intramedullary nailing has resulted in an increased number of tibial nailing in daily clinical practice. Despite adequate surgeon experience, tibial nailing is not without complications if proper techniques are not followed. A case of iatrogenic talar neck and medial malleolus frac- tures during intramedullary nailing of tibia in a 24-year-old male is reported. It is believed to be caused by forceful hammering of insertion zig with foot dorsiflexed. To the best of our knowledge, no such case has been reported in the literature. It is possible to reduce the risk of this complication by adoption of preventive measures.

Treatment of distal femoral nonunion and delayed union by using a retrograde intramedullary interlocking nail

Objective: To analyze the causes of distal femoral nonunion and delayed union and assess the outcome of the corresponding treatment, retrograde intramedullary interlocking nail (RIIN). Methods: From June 1995 to December 1998, 15 patients (9 males and 6 females) with distal femoral nonunion and delayed union were treated with RIIN. The average age of the patients was 34.5 years (23 46 years). Bone grafting was performed in 10 patients, closed reaming was done in the other 5 patients. Correction osteotomy was performed in 2 patients, and intra articular release of knee adhesion in 11 patients. X ray examination and knee society clinical rating system (KSS) were used to evaluate the results. Results: All fractures were followed up for at least 9 months with average follow up duration of 14.5 months (9 33 months). Solid union was documented in all patients at 6.4 months on average. There were no infections or malunions in this series. Based on the final follow up data, acceptable functional range of motion (ROM) of over 90° was achieved in most patients. The average ROM was 93.5° with significant improvement of 28° ( 42.7 %, P< 0.05 ) compared with the preoperative ROM. The average knee score was 96. Excellent ROM emerged in 13 patients. The knee function score was 90.5 on average. Conclusions: The main causes of distal femoral nonunion and delayed union are improper indications and improper use of the implants. RIIN is an effective alternative for treatment of distal femoral nonunion and delayed union because it can provide a stable and reliable fixation which is beneficial for early functional exercise of knee. Bone grafting, closed reaming and intra articular release of knee adhesion should be considered in order to enhance the bone healing and improve ROM and the knee function.