Does the magnetic-guided intramedullary nailing technique shorten operation time and radiation exposure?

Aim

The aim of this study is to show whether a new magnetic-guided locking technique is superior to a standard freehand technique in terms of operation time and radiation exposure. This treatment will be used for distal locking of the tibia during intramedullary nailing.

Methods

This randomized trial is done through 80 patients having tibial fractures with a mean age of 25 years (range 16–67 years). In the magnetic locking group, there were 20 fractures of the distal third, 16 of the shaft, and 4 of the proximal tibia; in the freehand group, these numbers were 15, 20, and 5, respectively. The parameters like operation time, distal locking time, radiation exposure duration, and dose were compared.

Results

We placed 100 distal locking screws in the magnetic locking group and 95 in the freehand group. Fluoroscopy was necessary only in the freehand group. All screws were correctly positioned the first time in both groups. The magnetic locking group had a shorter mean surgical time (52 ± 6.2 vs 70 ± 10.9 min; P < 0.01), a shorter mean distal locking time (5 ± 1.1 vs 16 ± 2.0 min; P < 0.01), and a shorter mean placement time for each screw (2 ± 0.5 vs 7 ± 1.2 min; P < 0.01). The magnetic locking group had lower mean radiation exposures (8 ± 4.5 vs 40 ± 7.6 s; P < 0.01) and mean radiation exposure (5.4 ± 2.5 vs 25 ± 6.8 mGy range; P < 0.01).

Conclusions

For distal locking during tibial intramedullary nailing, the magnetic locking system is as accurate as the standard freehand technique, but it has lower operative times and radiation exposures compared to the standard freehand technique. Therefore, the magnetic locking system should be preferred to current standard freehand techniques.     

Interlocking intramedullary nails. An improved method of screw placement combining image intensification and laser light.

Insertion of distal interlocking screws in femoral nails can be technically demanding and may entail substantial exposure. A method of insertion of femoral interlocking screws that uses a laser guiding system in addition to the standard image intensifier was used in an attempt to improve the accuracy of distal screw placement and to limit radiation exposure. Using this technique, 97% of the distal femoral drill holes attempted were successfully made with the first pass of a drill. Little or no resistance to the drill was met from contacting the femoral nail. Average fluoroscopy time was 0.4 minute. Laser-assisted screw placement requires relatively inexpensive modifications of existing equipment and is easy to master. Compared with the more commonly used freehand method, laser-assisted screw placement appears to offer a reduction in the amount of time and radiation exposure required to insert distal interlocking femoral screws.     

The effectiveness of the external distal aiming device in intramedullary fixation of tibial shaft fractures

Introduction

Intramedullary nailing has become a popular and effective procedure for the treatment of most fractures of the tibial diaphysis. However, distal interlocking screw placement under fluoroscopic control is responsible for the majority of the radiation exposure and a significant loss of surgical time in the entire nailing procedure. To limit fluoroscopy use, during distal interlocking screw placement, Orthofix^® has developed a distal targeting device which compensates for the inevitable deformation of the nail in the sagittal plane during its insertion. This prospective clinical study evaluates the efficacy of this distal targeting device for distal locking.

Materials and methods

One hundred and fifteen fresh tibial fractures in the same number of patients with a mean age of 37.5 years (17–85 years) were treated with operative stabilization using the Orthofix tibial nailing system.

Results

The mean duration of the operation was 38 min (20–55 min). A mean of four intra-operative plain X-rays (2–6 X-rays) were used in 103 cases to confirm guide wire placement, final nail insertion and accuracy of screws placement. The mean duration of the use of the image intensifier utilized in the remaining 12 fractures was 5 s (3–8 s). The distal targeting device failed in 12 (5.2%) distal locking screws.

Conclusion

This study demonstrates that distal locking can be performed easily and successfully with minimal exposure to radiation, once the surgeon develops a reasonable experience with the use of this distal targeting device.

     

Nail over nail technique for distal locking of femoral intramedullary nails

The free hand technique remains the most popular method for distal locking; however, radiation exposure is a major concern. In an endeavour to overcome this concern, distal locking with the nail over nail technique is evaluated. Seventy patients with femoral diaphyseal fractures treated by intramedullary nailing were divided in two groups for distal locking: either using the free hand technique (group I) or with the nail over nail technique (group II). The average number of images taken to achieve nail insertion without locking, for distal locking, and for the complete procedure in group I was 25.8, 24.2, and 50.08, respectively, compared with 24.8, 4.1, and 28.9, respectively, in group II (statistically extremely significant decrease in radiation). The nail over nail technique appears to be a reliable solution for decreasing radiation exposure during closed femoral intramedullary nailing. However, over-reaming of 1.5 mm is the key to the success of the technique.     

Distal locking of femoral nails under direct vision through a cortical window

We present a salvage technique for distal femoral interlocking under direct vision through a window in the anterior femoral cortex in a subgroup of six patients, among those presented to our institution during the last 10 years with a femoral shaft fracture treated with reamed, locked intramedullary nailing. The common characteristic of these patients was the performance of distal locking under direct vision through a small window in the anterior femoral cortex because of intraoperative dysfunction of the image intensifier. Screw insertion was successful in all cases. All fractures and all cortical windows healed uneventfully. No postoperative fractures occurred through the cortical defect. This technique, despite being a salvage one, has proven a safe alternative to the common distal targeting techniques. It can be used when an image intensifier is unavailable without jeopardizing the excellent clinical and radiographic outcome of reamed locked nailing of femoral shaft fractures.     

Fluoroscopic freehand and electromagnetic-guided targeting system for distal locking screws of humeral intramedullary nail

Purpose

The current techniques used to lock distal screws for the nailing of long bone fractures expose the surgeons, radiologists and patients to a hearty dose of ionizing radiation. The Sureshot? Distal Targeting System is a new technique that, with the same results, allows for shorter surgery times and, consequently, less exposure to radiation.

Materials and methods

The study was performed on 59 patients (34 males and 25 females) with a simple humerus fracture diagnosis, type 1.2.A according to the AO classification, who were divided into two groups. Group 1 was treated with ante-grade intramedullary nailing with distal locking screws inserted with a freehand technique. Group 2 was treated with the intramedullary nail using the Sureshot? Distal Targeting System. Two intra-operative time parameters were evaluated in both groups: the time needed for the positioning of the distal locking screws and the time of exposure to ionizing radiations during this procedure.

Results

Group 2 showed a lower average distal locking time compared to group 1 (645.48″ vs. 1023.57″) and also a lower average time of exposure to ionizing radiation than in group 1 (4.35″ vs. 28.96″).

Conclusion

The Sureshot? Distal Targeting System has proven to be equally effective when compared to the traditional techniques, with the added benefits of a significant reduction in both surgical time and risk factors related to the exposure to ionizing radiation for all the operating room staff and the patient.

     

Robotic distal locking of intramedullary nailing: Technical description and cadaveric testing

Interlocked intramedullary nailing is the treatment of choice for femoral shaft fractures. However, distal locking is a technically challenging part of the procedure that can result in distal femoral malrotation and high radiation exposure. We have tested a robotic procedure for robotic distal locking based on the computation of a drilling trajectory on two calibrated fluoroscopic images. Twenty distal holes were attempted in ten cadaveric femur specimens. Successful screw hole drilling was achieved at the first attempt in each of the ten specimens (20 drill holes in total). No failures were recorded. The average total number of images needed was 6.5 +/− 3.6. The average computation time was 16.5+/− 16.0 seconds. Robotic distal locking was feasible in this test and can be integrated into a fully robotic intramedullary nailing procedure.     

Distal Locking of Tibial Nails

The indications for intramedullary nailing have expanded to include most tibial shaft fractures. Nail design has improved since their first introduction, but distal locking remains a difficult part of the procedure, resulting in radiation exposure to the patient and the surgeon and increased operation time. To address these issues, we describe an alternative surgical technique using a newly designed distal targeting device that consists of a proximally mounted aiming arm, and we report the preliminary data from its use in all tibial shaft fractures amenable to surgery for a 2-year period. Sixty-three tibial shaft fractures were treated with this method. The mean duration of the distal locking was 6.5 minutes, and in all successful cases, radiation exposure for distal locking was two shots (one shot before targeting and another for the confirmation of proper screw insertion). Radiation exposure was on average 0.85 seconds (range, 0.4-1.2 seconds) and 1.4 mGy (range, 0.8-1.9 mGy). There were no major intraoperative complications related to the technique. The method has certain advantages and can reduce radiation exposure and operation time. Nonetheless, familiarity with the instrumentation is a prerequisite for accurate distal locking. LEVEL OF EVIDENCE: Level IV Therapeutic study.     

Contralateral reversed distal femoral locking plate for fixation of subtrochanteric femoral fractures

Purpose: Subtrochanteric fractures of the femur are being managed successfully with various intramedullary and extramedulary implants with reasonable success. However, these implants require precise placement under image intensifier guidance, which exposes the surgeon to substantial amount of radiation. It also restricts the management of these fractures at peripheral centers where facility of image intensifiers is not available. Keeping this in mind we designed this study to identify if contralateral reversed distal femoral locking plate can be used successfully without the use of image intensifier. Methods: Twenty-four consecutive patients (18 men and 6 women) with a mean age of 28 years (range 19e47 years) suffering subtrochanteric fractures of the femur underwent open reduction and internal fixation with reversed contralateral distal femoral locking plate. The outcome was assessed at the mean follow-up period of 3.2 years (range 2e4.6 years) using the Harris hip score. Results: Twenty-one fractures united with the primary procedure, with a mean time of consolidation being 11 weeks (range, 9e16 weeks). One patient developed superficial suture line infection, which resolved with oral antibiotics. Another patient had a fall 3 weeks after surgery and broke the plate. Repeat surgery with reversed distal femoral locking compression plate was performed along with bone grafting and the fracture united. Two cases had nonunion, which went in for union after bone grafting. The mean Harris hip score at the time of final follow-up was 90.63 (range 82-97). Conclusion: The reversed contralateral distal femoral plate is a biomechanically sound implant, which when used for fixation of the subtrochanteric fractures with minimal soft tissue stripping shows results comparable to those achieved by using other extramedullary implants as well as intramedullary devices. The added advantage of this implant is its usability in the absence of an image intensifier.     

Interlocking nailing without imaging: the challenges of locating distal slots and how to overcome them in SIGN intramedullary nailing

Placement of the distal interlocking screw is the most difficult part in all intramedullary nail interlocking screw systems and the Surgical Implant Generation Network (SIGN) interlocking system is not an exception. SIGN nails are interlocking implants designed with a precision instrumentation set for use in treatment of long bone fractures without an image intensifier. Locating the distal slots of SIGN nails could be challenging for young SIGN surgeons when treating very complex comminuted fractures and in obese patients. This study was stimulated by a patient who presented one year after surgery with knee pain due to a migrating nail because of missed distal screws. A total of 48 patients divided into two groups of 24 were studied retrospectively and prospectively. The retrospective studies revealed that failure to locate distal locking slots in ten antegrade nailing procedures was due to wrong entry point and comminution of the fracture. The challenges encountered led us to innovating methods to overcome the difficulties of placement of distal screws in a prospective study. Application of methods A and B made location of the distal slots easier in the prospective study even though there were more complex comminuted fractures. The methods also reduced the antegrade operation time by 1 hour 11 minutes. We concluded that SIGN nailing could be challenging and frustrating at the early learning stage. Application of the two innovative methods will make distal slot location easier. They will also make SIGN interlocking nailing less difficult for young SIGN surgeons as they journey through the learning curves.     

导航在长骨干骨折髓内钉固定中的应用

目的阐述透视导航技术在长骨干(股骨和胫骨)骨折,特别是在术中远端交锁髓内钉固定中的应用。探索在导航条件下术中应用髓内钉图像库开展远端交锁固定的可行性。此外,医用机器人的开发旨在被进一步用来改善手术程序的精确性。方法导航手术下,55例行股骨远端交锁钉固定和36例行胫骨远端交锁钉固定。其中13例术中应用图像库开展远端交锁固定。结果远端交锁固定成功率为97%。结论透视导航在长骨干骨折术中,使远端髓内交锁钉固定成功率增高。图像库的应用可以进一步减少患者和手术人员的X线辐射剂量。     

Observational prospective unblinded case-control study to evaluate the effect of the Gamma3® distal targeting system for long nails on radiation exposure and time for distal screw placement

PurposeTo determine if the DTS decreases radiation exposure (primary outcome measure), fluoroscopy time (secondary outcome measure), and time to distal screw placement (secondary outcome measure) compared to the freehand “perfect circles” method when used for locking of cephalomedullary nails in the treatment of femur fracturesMethodsFifty-eight patients with hip or femoral shaft fractures that were treated with a long cephalomedullary nail were enrolled in this study. Cohorts were determined based on the method of distal interlocking screw placement into either the “Perfect Circles” or “Distal Targeting” cohort. Time from cephalad screw placement to placement of final distal interlocking screw (seconds), radiation exposure (mGy), and fluoroscopy time (seconds) were compared between groups. Hospital quality measures were compared between cohorts.ResultsUse of the DTS resulted in 77% (4.3x) lower radiation exposure (p < 0.001), 64% (2.7x) lower fluoroscopy time (p < 0.001), and 60% (1.7x) lower intraoperative time from end of cephalad screw placement to end of distal interlocking screw placement (p < 0.001) compared to the freehand “perfect circles” method. There was no difference in 30-day or 90-day complication rates between cohorts.ConclusionThe Stryker Gamma3® Distal Targeting System is a safe, effective and efficient alternative to the freehand “perfect circles” method.     

A new mechanical aiming device for the placement of distal interlocking screws in femoral nails

Although the free-hand technique remains the most popular method for distal interlocking screw insertion, a proximally mounted “radiation-independent” device which compensates for implant deformation has been developed. In 15 intact human cadaveric femora the same surgeon performed statically locked intramedullary nailing using the distal aiming system. Operation time, distal screw insertion, total radiation time and accuracy of the interlocking screw placement were measured using a radiation-independent distal aiming system. The average total operation time was 21.2 ± 8.6 min, and the average distal locking time (2 screws) was 7.1 ± 2.4 min. The total operation time and the distal locking time declined over the first 10 cases. These times did not significantly improve in the subsequent 5 procedures. The average total fluoroscopy time was 28.1 ± 16.6 s. None of the screw placements using the distal aiming device required the use of fluoroscopy. Drill-nail contact was absent in 5 drillings, mild in 9 drillings, moderate in 16 drillings, and severe in none. Measurement of screw damage showed in 55 of 60 measurements wear of less than 15 μm. There were no failures or major complications. A minor complication related to distal locking was observed in one specimen. This study suggests that distal interlocking screws can be placed successfully using a radiation-independent aiming arm-based system, which accounts for nail deformations. The distal aiming device (DAD) can be learned easily. The main advantages of the aiming arm include the elimination of radiation during distal interlocking and precise screw placement with little insertion-related hardware damage. Received: 23 Juni 1997     

A mechanical distal aiming device for distal locking in femoral nails.

Although the free hand technique remains the most popular method for distal interlocking screw insertion, proximally mounted radiation independent devices that compensate for implant deformation recently have been developed for the femur. However, the benefits of such systems have not been determined. This study prospectively compared the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement when using a radiation independent distal aiming system with those using the free hand technique. In 20 paired intact anatomic specimen femurs, one surgeon experienced only in the free hand technique performed statically locked intramedullary nailing using the two methods. For the aiming system and free hand technique, respectively, the total operation time was 19.1 +/- 8.4 minutes versus 20.9 +/- 11.3 minutes, the distal locking time was 6.6 +/- 2.4 minutes versus 4.8 +/- 1.5 minutes, the total fluoroscopy time was 23 +/- 17 seconds versus 69 +/- 34 seconds, and the distal locking fluoroscopy time was 0 versus 37 +/- 15.5 seconds. There were no failures in either group. Drill nail contact and distal screw damage were greater with the free hand technique. This study suggests that the main advantages of the aiming arm compared with the free hand technique include the elimination of radiation during distal interlocking and more precise screw placement with decreased insertion related hardware damage.     

Evaluation of the Stryker S2 IM Nail Distal Targeting Device for reduction of radiation exposure: a case series study

Distal locking is one challenging step during intramedullary nailing of femoral shaft fractures that can lead to an increase of radiation exposure. In the present study, the authors describe a technique for the distal locking of femoral nails, implementing a new targeting device in an attempt to reduce radiation exposure and operational time. Over a 2-year period, 127 consecutive cases of femoral shaft fractures were included in the study. All cases were treated with nailing of femoral shaft fractures with an unslotted reamed antegrade femoral nail and distal locking was performed with the use of a proximally mounted aiming device. Mean duration of the procedure was 63.5 ± 18.1 min while the duration for distal locking was 6.6 ± 2.6 min. In all successful cases, exposure from intraoperative fluoroscopy was 17.2 ± 7.4 s for the whole operative procedure, and for distal locking was 2 shots, 1.35 s (range, 0.9–2.2 s) and 1.9 mGy (range, 1.1–2.9 mGy). Five cases (3.9%) were unsuccessful, but overall no intraoperative complications were encountered from the application of this technique. The ability of the device to correspond to the level of nail deformation and to properly identify the distal holes, reduced exposure to radiation compared to other published reports, and should be considered as a valuable tool for distal locking of femoral fractures.     

Fluoroscopy as an imaging means for computer-assisted surgical navigation.

OBJECTIVE: Intraoperative fluoroscopy is a valuable tool for visualizing underlying bone and surgical tool positions in orthopedic procedures. Disadvantages of this technology include the need for continued radiation exposure for visual control, and cumbersome means of alignment. The purpose of this article was to highlight a new concept for a computer-assisted freehand navigation system that uses single intraoperatively acquired fluoroscopic images as a basis for real-time navigation of surgical tools. MATERIALS AND METHODS: Optoelectronic markers are placed on surgical tools, a patient reference, and the fluoroscope to track their position in space. Projection properties of the fluoroscope are acquired through an initial precalibration procedure using a tracked radiopaque phantom grid. Corrections are applied to compensate for both the fluoroscope's image intensifier distortions and the mechanical bending of the C-arm frame. This enables real-time simulation of surgical tool positions simultaneously in several single-shot fluoroscopic images. In addition, through optoelectronically tracked digitization of a target viewpoint, the fluoroscope can be numerically aligned at precise angles relative to the patient without any X-ray exposure. RESULTS: This article shows the feasibility of this technology through its use in cadaver trials to perform the difficult task of distal locking of femoral nails.     

Computer assisted orthopaedic surgical system for insertion of distal locking screws in intra-medullary nails: a valid and reliable navigation system

The insertion of distal locking screws is a difficult task in intra-medullary (IM) nailing operations of long bones and contributes a significant proportion to the overall operating time. The current technique to insert these screws uses numerous fluoroscopic images and depends on the skills and expertise of the surgeon. The Computer Assisted Orthopaedic Surgical System (CAOSS) was developed to assist orthopaedic surgeons in these operations. The laboratory based test results for insertion of distal locking screws in IM nailing procedures are presented and discussed in terms of accuracy and as part of the validation process to introduce new CAOS procedures into clinical use. This study shows that CAOSS in IM nailing is robust and reliable. Positional accuracy was shown to be within 0.3 mm and angular accuracy within 0.2 degrees with femoral IM nail. CAOSS was also shown to be very reliable and accurate at different angles of distal screws in fluoroscopic image space.     

Insertion of distal locking screws of tibial intramedullary nails: A comparison between the free-hand technique and the SURESHOT™ Distal Targeting System

Introduction

Positioning of the distal locking screws of an intramedullary nail is often challenging and time consuming because of difficult localisation of the distal locking holes, potential screw malalignment and nail deformation during insertion. The standard free-hand technique under fluoroscopic control involves considerable radiation exposure of both the patient and the surgical team. In this study, we aimed to compare the free-hand technique with a new system that utilises electromagnetic (EM) tracking data (SURESHOT™ Distal Targeting System) to localise distal locking holes.

Material and methods

Patients admitted from March 2010 to January 2013 for tibial fracture that required intramedullary nailing were analysed retrospectively. We compared intraoperative radiation exposure time and distal locking time in patients treated with the standard free-hand technique and distal locking using the EM field-generating device. Intraoperative radiation exposure time and distal locking time were used for comparison.

Results

Data from a total of 50 patients were analysed. The standard free-hand technique and the EM field-generating device were used in 25 (group 1) and 25 (group 2) patients, respectively. Mean distal locking time was 1258.6 (450–2289) s in group 1 and 603.5 (360–1140) s in group 2. Mean radiation exposure time was 19.4 (6–33) s in group 1 and 4.6 (1–10) s in group 2.

Conclusion

The EM field-generating device significantly reduces distal locking time and, more importantly, significantly decreases duration of exposure to ionising radiation.     

Intraoperative radiation exposure in displaced supracondylar humeral fractures: a comparison of surgical methods

Crossed K-wires, descending elastic stable intramedullary nailing and radial external fixator are alternatives in the operative treatment of displaced supracondylar humeral fractures. Only little knowledge of intraoperative radiation exposure exists in those procedures. We found average image intensifier times of 30.7 s for K-wires, 41.4 s for the external fixator and 80.0 s for elastic stable intramedullary nailing. Extensively increased fluoroscopy times was seen in cases switched from closed to open reduction intraoperatively. To avoid unnecessary intraoperative radiation exposure for patient, surgeon and staff, limits of radiation time are recommended as an additional indicator to change the surgical procedure to another fixation method or open reduction.     

The AO distal locking aiming device: an evaluation of efficacy and learning curve

OBJECTIVES: The AO nail mounted 'distal locking aiming device', developed to obtain radiation independent distal locking, has an unproven efficacy in a large clinical setting. This prospective study compares the efficacy and learning curve of the distal aiming device with the popular 'free hand technique'. MATERIALS AND METHODS: Distal locking in thirty cases of statically locked intramedullary femur nailing using the distal aiming device for rotationally stiff unslotted AO SUN nails was prospectively compared with the same number using the free-hand technique with regard to duration, radiation exposure, accuracy of screw placement, and learning curve. RESULTS AND DISCUSSION: For the free-hand technique and the distal aiming system respectively, the average distal locking time was 35.8+/-18.6 versus 19.3+/-9.8 minutes, and the average number of images taken to achieve distal locking was 11.5+/-3.4 versus 3.8+/-3.5. The decrease in average distal locking time by 46.1% and in radiation by 70.0% with the distal aiming system is statistically significant at P<0.001. There were three failures of the distal aiming device and these were converted to the free-hand technique. The learning curve for the distal aiming device was shorter and more predictable than that with the free hand technique. We also analyse the failures and associated pitfalls with the system. CONCLUSIONS: We found the AO distal locking aiming device to be an accurate, radiation-independent jig with a short and predictable learning curve.