- Email: [email protected]
Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing
G Model JINJ 7750 No. of Pages 4
Injury, Int. J. Care Injured xxx (2018) xxx–xxx
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing M. Williamson* ,a , E. Iliopoulosa , R. Williamsb , A. Trompetera a b
Trauma & Orthopaedics, St George’s University Hospitals NHS Foundation Trust, London, SW17 0QT, United Kingdom Department of Radiology, St George’s University Hospitals NHS Foundation Trust, London, SW17 0QT, United Kingdom
A R T I C L E I N F O
Keywords: Tibial nail Tibia fracture Proximal tibial fractures Suprapatellar tibial nail Fluoroscopy Radiation exposure Surgical technique
A B S T R A C T
Background: Fractures of the tibial shaft are routinely managed with intramedullary nailing. An increasingly accepted technique is the suprapatellar extended leg method. The aim of this study was to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times and lower radiation doses when compared to the traditional infrapatellar technique. Study design and methods: Data from 200 consecutive intramedullary tibial nailing operations in our level 1 Major Trauma Centre were retrospectively collected from a prospective database (January 2014– December 2017). Only acute diaphyseal nailing procedures were included. The operations were performed by seven senior trauma consultants experienced in both suprapatellar and infrapatellar tibial nailing. The operations were divided into two groups: infrapatellar and suprapatellar. Intraoperative radiation time and dose data were collected. Results: A total of 90 cases were included and analysed. The majority of the patients were male (82%). 37 operations were infrapatellar and 53 were suprapatellar. Independent samples t-test revealed lower radiation time and dose for the suprapatellar group. The infrapatellar group had a mean radiation time of 129.7 56.6 s versus 94.4 47.9 s for the suprapatellar group. The infrapatellar group had a mean radiation dose (Dose Area Product) 53.6 34.2 cGY cm2 versus 38.2 26.7 cGY cm2 for the suprapatellar group. The difference in mean radiation time and mean radiation dose were both significant (p = 0.002 and p = 0.02 respectively). Conclusions: Suprapatellar tibial nailing is an increasingly accepted technique in the management of tibial fractures. It is shown here that amongst surgeons experienced in both suprapatellar and infrapatellar nailing techniques, the suprapatellar approach trends towards lower use of intra-operative fluoroscopy as measured by time and dose and thus potentially lower radiation exposure to the operating surgeon, assistants and patient. © 2018 Published by Elsevier Ltd.
Introduction Fractures of the tibial shaft are routinely managed with intramedullary nailing [1]. Their origins lie with Gerhard Küntscher and his V-shaped nail, which he introduced during World War II. The technique and design have been developed over subsequent decades [2]. Most commonly, an infrapatellar nail insertion technique is used to treat tibial shaft fractures. Typically, the knee is flexed to 90 over either a support, or the end of the operating table, or the leg is placed into a figure of four position. Surgical approaches to facilitate nail entry point are typically either the transtendinous
* Corresponding author at: 44 Mafeking Avenue, TW8 0NH, United Kingdom. E-mail address: [email protected] (M. Williamson).
approach which involves splitting the patellar tendon or a paratendinous approach involving an incision to one side of the patellar tendon [3]. In proximal fractures of the tibia there is the risk of apex anterior angular deformity due to the pull of the patellar tendon. During infrapatellar nailing, this deformity is further exaggerated when the knee is flexed to gain access to the entry point. In order to overcome this, nailing the tibia with the leg extended was described by Tornetta et al. [4]. Early extended nailing typically involved a parapatellar approach akin to that used in knee arthroplasty and required extensive mobilisation of the patella and patellar tendon to gain access to the correct nail entry point. More recently, the suprapatellar/retropateller approach for extended knee tibial nailing has gained popularity. Here, the incision is located proximal to the patella and the instrumentation for nailing of the tibia is passed behind the patella through the knee
https://doi.org/10.1016/j.injury.2018.07.004 0020-1383/© 2018 Published by Elsevier Ltd.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
G Model JINJ 7750 No. of Pages 4
2
M. Williamson et al. / Injury, Int. J. Care Injured xxx (2018) xxx–xxx
joint. Various studies have suggested benefits with the suprapatellar technique such as easier fracture reduction and lower incidence of anterior knee pain [5]. The senior author of this study, experienced in both supra and infrapatellar tibial nailing techniques, has noted the suprapatellar technique appears to be faster. It involves an easier setup, the entry point for the wire is predictable and reproducible and it uses the anatomy of the trochlea to guide the trochar into the right place each time [6]. This decreased operation time may offer a further benefit of lower intra-operative fluoroscopy time and dose. Fluoroscopic imaging is routinely used during orthopaedic procedures, and is essential for the ensuring accurate fracture reduction and implant positioning in tibial nailing. However, the use of ionising radiation intra-operatively can lead to harmful biological effects in both patients and staff. An awareness of the detrimental biological effects of ionising radiation is essential. X-rays are sub-atomic particles from the highest part of the electromagnetic spectrum. At the energies associated with medical imaging, these particles have enough energy to ionise an atom and release an electron, leading to possible tissue damage which, can result in cell mutation or death. The higher the dose of radiation the greater the chance that tissue damage will occur. This risk of biological damage is known as the stochastic effect; it implies that no dose of radiation is safe and we should therefore always aim to use the lowest dose reasonably achievable [7–9]. As such, any procedure which utilises lower dosage of ionising radiation should be encouraged. The aim of this study was, therefore, to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times and lower radiation doses when compared to the traditional infrapatellar technique.
The Stryker, Mahwah, NJ 07430, USA, T2 Tibial Nail was used for both infrapatellar and suprapatellar techniques. The infrapatellar intramedullary tibial nails were performed using a transtendinous approach. The suprapatellar nails were performed with the patient supine on a radiolucent table with the knee in a semi-extended position of between five to ten degrees. A three to five centimetre incision was made proximal to the proximal pole of the patella and the quadriceps tendon was split longitudinally. Specific instrumentation was required - the sleeve and trocar were inserted through the patellofemoral joint and a guide wire inserted through the trocar. The same entry point for the nail was used as for the infrapatellar technique. Two Kirschner wires were used to secure the trocar in place and the opening drill was used to access the medullary canal. From this point on, the two procedures were identical [10]. Results After exclusions, a total of 90 patients were included in the study. Fig. 1 demonstrates how the 90 study patients were derived from the original 200 procedures. The majority of the patients were male (82%). There were 37 cases in the infrapatellar tibial nailing group and 53 cases in the suprapatellar tibial nailing group. Overall, the mean fluoroscopy time of the cohort was 108.9 54.2 s and the mean radiation dose (Dose Area Product– DAP) was 44.4 30.7 cGY cm2.
Study design and methods Data from 200 consecutive intramedullary tibial nailing operations were included. These data were retrospectively analysed from a prospectively collected database (January 2014– December 2017) at our level 1 Major Trauma Centre. Only acute diaphyseal nailing procedures were included. Tibial nailing for non-union, exchange tibial nailing, tibial nailing combined with other orthopaedic operations, nailing of proximal and distal tibia fractures requiring associated articular reconstruction and operations with insufficient radiation data were excluded from the study. Procedures where single blocking screws were used were included. The operations were performed by seven senior trauma consultants experienced in both suprapatellar and infrapatellar tibial nailing. The first ten cases for each consultant using the suprapatellar technique (approximately six months per consultant), were excluded to allow for initial learning curves. Intraoperative radiation time and dose data were recorded at the time of surgery as part of the routine Ionising Radiation (Medical Exposure) Regulations (IR(ME)R) 2000 [9]. Dose data was measured as the Dose Area Product (DAP). This is defined as the absorbed dose multiplied by the specific body area irradiated. DAP is typically used to assess the radiation risk during X-ray examinations. It is a better indicator of overall risk of inducing cancer than the total applied radiation dose within the field because it reflects the specific dose absorbed by the area of tissue irradiated. The operations were divided into two groups; infra- and suprapatellar tibial nailing. IBM SPSS statistics ver. 23.0 (SPSS Inc, Chicago, IL, USA) was used for statistical analysis. Statistical significance was set at 0.05. Independent samples t-test was used to compare means.
Fig. 1. Flow diagram of how the 90 intramedullary (IM) tibial nails were derived from the 200 procedures. SP = suprapatellar insertion technique, IP = infrapatellar insertion technique.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
G Model JINJ 7750 No. of Pages 4
M. Williamson et al. / Injury, Int. J. Care Injured xxx (2018) xxx–xxx
Independent samples t-test revealed lower radiation time and dose for the suprapatellar group. The infrapatellar group had a mean radiation time of 129.7 56.6 s versus a mean radiation time of 94.4 47.9 s for the suprapatellar group (Table 1). The infrapatellar group had a mean radiation dose 53.6 34.2 cGY cm2 versus the suprapatellar group which had a mean radiation dose of 38.2 26.7 cGY cm2 (Table 1). The difference in mean radiation time and mean radiation dose were both statistically significant (p = 0.002 and p = 0.02 respectively). Discussion Intramedullary nailing has long been established as the gold standard treatment for tibial shaft fractures. Whilst the traditional infrapatellar approach has been favoured, it presents certain difficulties regarding fracture reduction, anterior knee pain and accurate entry point identification. The suprapatellar approach has potentially offered solutions to these problems. This study demonstrates the suprapatellar nailing technique lowers the use of intra-operative fluoroscopy as measured by time and dose. An advantage of the suprapatellar tibial nail is in the reduction and stabilisation of proximal tibial fractures. These fractures can be technically challenging because of the anterior angulation of the patellar tendon. This deformity is further exaggerated when the knee is flexed to gain access to the entry point during the infrapatellar technique. There is evidence that for the suprapatellar technique in the semi extended position, fracture reduction was more accurate in terms of angulation and translation in the coronal plane [4]. A significant complication of infrapatellar tibial nails is the incidence of anterior knee pain [11]. Previous studies have shown that there is either no significant difference or even reduction of anterior knee pain between the suprapatellar technique and the infrapatellar technique [5,6]. Further benefits of suprapatellar tibial nailing include that the incision is at a greater distance away from where commonly the soft tissue damage or open fracture wound occurs over the tibia [12], there is a decreased risk of patellar tendon damage and damage to the infrapatellar nerve [13]. An accurate nail entry point is key to the success of any tibial nailing. It has been shown that the centre of the entry point is just medial to the lateral tibial spine on the anteroposterior radiograph and immediately anterior to the articular margin on the lateral radiograph [3]. This entry point is constant and remains the same for all nailing procedures regardless of approach or instrumentation. Jones et al showed the nail insertion point is more accurate with the suprapatellar tibial nailing technique [6]. The reduced fluoroscopy time shown here may in part be due to the ease at which the entry point for a nail is achieved with the suprapatellar technique. Reviews of the suprapatellar tibial nailing technique also suggest that it is easier to achieve and maintain reduction of the fracture. Furthermore, intra-operative fluoroscopy is easier as the knee does not need to be repositioned for the anteroposterior and lateral radiographs. The knee can be kept in the original semi-extended position that was required for
Table 1 Radiation data for suprapatellar and infrapatellar intramedullary tibial nails. Radiation Time (secs)
Mean
Standard Deviation
Infrapatellar Suprapatellar
129.7 94.4
56.6 47.9
Dose DAP (cGY/cm2)
Mean
Standard Deviation
Infrapatellar Suprapatellar
53.6 38.2
34.2 26.7
3
reduction and nail insertion [14,15]. This decreases the time between anteroposterior and lateral radiographs. The Ionising Radiation (Medical Exposure) Regulations (IR(ME) R) 2000 is UK legislation which provides a framework intended to protect patients from the hazards associated with ionising radiation and advises that an awareness of the detrimental biological effects of ionising radiation is essential. Ionising radiation can directly or indirectly interact with DNA, disrupt water molecules and create reactive oxygen species leading to biological tissue damage. This can lead to cancerous and noncancerous diseases [8,9,16]. Intra-operative radiation exposure remains a significant concern to all theatre staff and limiting radiation has become an important topic in orthopaedics [7]. For the surgeon and other theatre staff, scattered radiation is the leading cause of exposure and directly relates to the patient’s DAP value. Therefore, reducing patient dose will directly translate in the reduced exposure of the theatre team. For patients undergoing procedures in theatre, the primary beam is the only source of radiation. There are several variables that will influence the final dose value. These can be divided into radiographer factors, surgical technique factors and patient factors. Patient factors, such as patient size, are understandably difficult to influence. Radiographer factors, such as intelligent collimation, limiting the use of magnification and using a reduced dose pulsed exposure where possible are dependent on the skill of the radiographer and team work with the surgeon. In general terms, surgeons can limit radiation exposure by minimising frequency of exposure and removing unnecessary surgical objects from the primary beam (exposure factors will change to try and penetrate metallic objects). However, there are many surgical technique factors that influence the final dose value. These include the positioning of the X-ray tube beneath the patient, minimising angles, patient positioning and limiting the use of supportive blocks. Therefore, it is possible the final radiation dose is increased in the infrapatellar technique compared to the suprapatellar technique because of aspects such as the use of supportive blocks and because of the difficulty in obtaining the anteroposterior and lateral radiographs, which increases the angle of the beam. A previous study by Sun et al. showed a decrease in fluoroscopy time for suprapatellar nails compared to infrapatellar nails in a total of 162 tibial nails [17]. However, that study did not look at fluoroscopic dose, and the fluoroscopic time they reported on was only a secondary outcome. Our study also shows that radiation dose is reduced during the suprapatellar technique which more accurately represents radiation exposure to the patient and theatre staff. Furthermore, our study set out to specifically answer the question surrounding radiation time and dose. The two major uncontrolled variables in the present study were: the skill and experience of the surgeon; and the difficulty of the fracture. Only seven consultant surgeons were included for analysis. They are experienced trauma surgeons working at a major trauma centre and have extensive experience in both suprapatellar and infrapatellar tibial nailing. This was done to rule out bias created by less experienced surgeons in either technique, or surgeons with more experience in one nailing approach. In addition, the first ten cases, representing initial learning curves in suprapatellar techniques for each consultant, (approximately six months per consultant) were excluded. Complex tibial nailing procedures and those procedures that involved treatment of further fractures were excluded to minimise these cases skewing the results. Conclusion This study aimed to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
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and lower radiation doses when compared to the traditional infrapatellar technique. Both mean radiation time and mean radiation dose were lower in the suprapatellar group. Therefore, this study shows that amongst surgeons experienced in both supra and infrapatellar nailing techniques, the suprapatellar approach has significantly lower use of intra-operative fluoroscopy as measured by time and dose and thus potentially lower radiation exposure to the operating surgeon, assistants and patient. Funding None. Conflict of interest statement A. Trompeter has an R+D/Education consultancy contract with Stryker. However, no payment or work is related to this project in anyway. The remaining authors have no other conflicts of interest including no financial or personal relationships with other people or organisations that could inappropriately influence (bias) this work. References [1] Finkemeier C.G., Schmidt AH, Kyle RF, Templeman DC, Varecka TF. A prospective, randomized study of intramedullary nails inserted with and without reaming for the treatment of open and closed fractures of the tibial shaft. J Orthop Trauma 2000;14(March–April (3)). [2] Bong MR, Koval KJ, Egol KA. The history of intramedullary nailing. Bull NYU Hosp Dis 2006;64(3–4):94–7. [3] Zelle B, Boni G. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures. Patient Saf Surg 2015;9:40.
[4] Tornetta 3rd P, Collins E. Semiextended position of intramedullary nailing of the proximal tibia. Clin Orthop Relat Res 1996;328(July):185–9. [5] Sanders RW, DiPasquale TG, Jordan CJ, Arrington JA, Sagi HC. Semiextended intramedullary nailing of the tibia using a suprapatellarapproach: radiographic results and clinical outcomes at a minimum of 12 months followup. J Orthop Trauma 2014;28(May (5)):24. [6] Jones M, Parry M, Whitehouse M, Mitchell S. Radiologic outcome and patientreported function after intramedullary nailing: a comparison of the retropatellar and infrapatellar approach. J Orthop Trauma 2014;28(May (5)):256–62. [7] Williams H, Widdowfield M, Cosson P. The radiographer’s multidisciplinary team role in theatre scenarios. Radiography 2015;21:165–71. [8] Tootell A, Szczepura K, Hogg P. An overview of measuring and modelling dose and risk from ionising radiation for medical exposures. Radiography 2014;20:323–32. [9] Department of Health. The ionising radiation (medical exposure) regulations 2000. IR(ME)R together with notes on good practice. London: TSO; 2000. . (Accessed January 2018) http://www.opsi.gov.uk/si/si2000/20001059.htm. [10] Stryker Orthopaedics, T2 tibial nailing system operative technique, 325 Corporate Dr. Mahwah NJ 07110, www.stryker.com (Accessed January 2018). [11] Court-Brown CM, Gustilo T, Shaw AD. Knee pain after intramedullary tibial nailing: its incidence, etiology, and outcome. J Orthop Trauma 1997;11 (February–March (2)):103–5. [12] Franke J, Hohendorff B, Alt V, Thormann U, Schnettler R. Suprapatellar nailing of tibial fractures–indications and technique. Injury 2016;47(February (2)):495–501. [13] Fu B. Locked META intramedullary nailing fixation for tibial fractures via a suprapatellar approach. Indian J Orthop 2016;50(May–June (3)):283–9. [14] Eastman J, Tseng S, Lo E, Li CS, Yoo B, Lee M. Retropatellar technique for intramedullary nailing of proximal tibia fractures: a cadaveric assessment. J Orthop Trauma 2010;24(November (11)):672–6. [15] Gelbke MK, Coombs D, Powell S, DiPasquale TG. Suprapatellar versus infrapatellar intramedullary nail insertion of the tibia: a cadaveric model for comparison of patellofemoral contact pressures and forces. J Orthop Trauma 2010;24(November (11)):665–71. [16] Cloutier D. Radiation exposure in orthopaedics. JBJS J Orthopaedics Phys Assist 2015;3(April (2)):5–9. [17] Sun Q, Nie X, Gong J, Wu J, Li R, Ge W, et al. The outcome comparison of the suprapatellar approach and infrapatellar approach for tibia intramedullary nailing. Int Orthop 2016;40(December (12))2611–7 Epub 2016 May 7.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
Injury, Int. J. Care Injured xxx (2018) xxx–xxx
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing M. Williamson* ,a , E. Iliopoulosa , R. Williamsb , A. Trompetera a b
Trauma & Orthopaedics, St George’s University Hospitals NHS Foundation Trust, London, SW17 0QT, United Kingdom Department of Radiology, St George’s University Hospitals NHS Foundation Trust, London, SW17 0QT, United Kingdom
A R T I C L E I N F O
Keywords: Tibial nail Tibia fracture Proximal tibial fractures Suprapatellar tibial nail Fluoroscopy Radiation exposure Surgical technique
A B S T R A C T
Background: Fractures of the tibial shaft are routinely managed with intramedullary nailing. An increasingly accepted technique is the suprapatellar extended leg method. The aim of this study was to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times and lower radiation doses when compared to the traditional infrapatellar technique. Study design and methods: Data from 200 consecutive intramedullary tibial nailing operations in our level 1 Major Trauma Centre were retrospectively collected from a prospective database (January 2014– December 2017). Only acute diaphyseal nailing procedures were included. The operations were performed by seven senior trauma consultants experienced in both suprapatellar and infrapatellar tibial nailing. The operations were divided into two groups: infrapatellar and suprapatellar. Intraoperative radiation time and dose data were collected. Results: A total of 90 cases were included and analysed. The majority of the patients were male (82%). 37 operations were infrapatellar and 53 were suprapatellar. Independent samples t-test revealed lower radiation time and dose for the suprapatellar group. The infrapatellar group had a mean radiation time of 129.7 56.6 s versus 94.4 47.9 s for the suprapatellar group. The infrapatellar group had a mean radiation dose (Dose Area Product) 53.6 34.2 cGY cm2 versus 38.2 26.7 cGY cm2 for the suprapatellar group. The difference in mean radiation time and mean radiation dose were both significant (p = 0.002 and p = 0.02 respectively). Conclusions: Suprapatellar tibial nailing is an increasingly accepted technique in the management of tibial fractures. It is shown here that amongst surgeons experienced in both suprapatellar and infrapatellar nailing techniques, the suprapatellar approach trends towards lower use of intra-operative fluoroscopy as measured by time and dose and thus potentially lower radiation exposure to the operating surgeon, assistants and patient. © 2018 Published by Elsevier Ltd.
Introduction Fractures of the tibial shaft are routinely managed with intramedullary nailing [1]. Their origins lie with Gerhard Küntscher and his V-shaped nail, which he introduced during World War II. The technique and design have been developed over subsequent decades [2]. Most commonly, an infrapatellar nail insertion technique is used to treat tibial shaft fractures. Typically, the knee is flexed to 90 over either a support, or the end of the operating table, or the leg is placed into a figure of four position. Surgical approaches to facilitate nail entry point are typically either the transtendinous
* Corresponding author at: 44 Mafeking Avenue, TW8 0NH, United Kingdom. E-mail address: [email protected] (M. Williamson).
approach which involves splitting the patellar tendon or a paratendinous approach involving an incision to one side of the patellar tendon [3]. In proximal fractures of the tibia there is the risk of apex anterior angular deformity due to the pull of the patellar tendon. During infrapatellar nailing, this deformity is further exaggerated when the knee is flexed to gain access to the entry point. In order to overcome this, nailing the tibia with the leg extended was described by Tornetta et al. [4]. Early extended nailing typically involved a parapatellar approach akin to that used in knee arthroplasty and required extensive mobilisation of the patella and patellar tendon to gain access to the correct nail entry point. More recently, the suprapatellar/retropateller approach for extended knee tibial nailing has gained popularity. Here, the incision is located proximal to the patella and the instrumentation for nailing of the tibia is passed behind the patella through the knee
https://doi.org/10.1016/j.injury.2018.07.004 0020-1383/© 2018 Published by Elsevier Ltd.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
G Model JINJ 7750 No. of Pages 4
2
M. Williamson et al. / Injury, Int. J. Care Injured xxx (2018) xxx–xxx
joint. Various studies have suggested benefits with the suprapatellar technique such as easier fracture reduction and lower incidence of anterior knee pain [5]. The senior author of this study, experienced in both supra and infrapatellar tibial nailing techniques, has noted the suprapatellar technique appears to be faster. It involves an easier setup, the entry point for the wire is predictable and reproducible and it uses the anatomy of the trochlea to guide the trochar into the right place each time [6]. This decreased operation time may offer a further benefit of lower intra-operative fluoroscopy time and dose. Fluoroscopic imaging is routinely used during orthopaedic procedures, and is essential for the ensuring accurate fracture reduction and implant positioning in tibial nailing. However, the use of ionising radiation intra-operatively can lead to harmful biological effects in both patients and staff. An awareness of the detrimental biological effects of ionising radiation is essential. X-rays are sub-atomic particles from the highest part of the electromagnetic spectrum. At the energies associated with medical imaging, these particles have enough energy to ionise an atom and release an electron, leading to possible tissue damage which, can result in cell mutation or death. The higher the dose of radiation the greater the chance that tissue damage will occur. This risk of biological damage is known as the stochastic effect; it implies that no dose of radiation is safe and we should therefore always aim to use the lowest dose reasonably achievable [7–9]. As such, any procedure which utilises lower dosage of ionising radiation should be encouraged. The aim of this study was, therefore, to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times and lower radiation doses when compared to the traditional infrapatellar technique.
The Stryker, Mahwah, NJ 07430, USA, T2 Tibial Nail was used for both infrapatellar and suprapatellar techniques. The infrapatellar intramedullary tibial nails were performed using a transtendinous approach. The suprapatellar nails were performed with the patient supine on a radiolucent table with the knee in a semi-extended position of between five to ten degrees. A three to five centimetre incision was made proximal to the proximal pole of the patella and the quadriceps tendon was split longitudinally. Specific instrumentation was required - the sleeve and trocar were inserted through the patellofemoral joint and a guide wire inserted through the trocar. The same entry point for the nail was used as for the infrapatellar technique. Two Kirschner wires were used to secure the trocar in place and the opening drill was used to access the medullary canal. From this point on, the two procedures were identical [10]. Results After exclusions, a total of 90 patients were included in the study. Fig. 1 demonstrates how the 90 study patients were derived from the original 200 procedures. The majority of the patients were male (82%). There were 37 cases in the infrapatellar tibial nailing group and 53 cases in the suprapatellar tibial nailing group. Overall, the mean fluoroscopy time of the cohort was 108.9 54.2 s and the mean radiation dose (Dose Area Product– DAP) was 44.4 30.7 cGY cm2.
Study design and methods Data from 200 consecutive intramedullary tibial nailing operations were included. These data were retrospectively analysed from a prospectively collected database (January 2014– December 2017) at our level 1 Major Trauma Centre. Only acute diaphyseal nailing procedures were included. Tibial nailing for non-union, exchange tibial nailing, tibial nailing combined with other orthopaedic operations, nailing of proximal and distal tibia fractures requiring associated articular reconstruction and operations with insufficient radiation data were excluded from the study. Procedures where single blocking screws were used were included. The operations were performed by seven senior trauma consultants experienced in both suprapatellar and infrapatellar tibial nailing. The first ten cases for each consultant using the suprapatellar technique (approximately six months per consultant), were excluded to allow for initial learning curves. Intraoperative radiation time and dose data were recorded at the time of surgery as part of the routine Ionising Radiation (Medical Exposure) Regulations (IR(ME)R) 2000 [9]. Dose data was measured as the Dose Area Product (DAP). This is defined as the absorbed dose multiplied by the specific body area irradiated. DAP is typically used to assess the radiation risk during X-ray examinations. It is a better indicator of overall risk of inducing cancer than the total applied radiation dose within the field because it reflects the specific dose absorbed by the area of tissue irradiated. The operations were divided into two groups; infra- and suprapatellar tibial nailing. IBM SPSS statistics ver. 23.0 (SPSS Inc, Chicago, IL, USA) was used for statistical analysis. Statistical significance was set at 0.05. Independent samples t-test was used to compare means.
Fig. 1. Flow diagram of how the 90 intramedullary (IM) tibial nails were derived from the 200 procedures. SP = suprapatellar insertion technique, IP = infrapatellar insertion technique.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
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Independent samples t-test revealed lower radiation time and dose for the suprapatellar group. The infrapatellar group had a mean radiation time of 129.7 56.6 s versus a mean radiation time of 94.4 47.9 s for the suprapatellar group (Table 1). The infrapatellar group had a mean radiation dose 53.6 34.2 cGY cm2 versus the suprapatellar group which had a mean radiation dose of 38.2 26.7 cGY cm2 (Table 1). The difference in mean radiation time and mean radiation dose were both statistically significant (p = 0.002 and p = 0.02 respectively). Discussion Intramedullary nailing has long been established as the gold standard treatment for tibial shaft fractures. Whilst the traditional infrapatellar approach has been favoured, it presents certain difficulties regarding fracture reduction, anterior knee pain and accurate entry point identification. The suprapatellar approach has potentially offered solutions to these problems. This study demonstrates the suprapatellar nailing technique lowers the use of intra-operative fluoroscopy as measured by time and dose. An advantage of the suprapatellar tibial nail is in the reduction and stabilisation of proximal tibial fractures. These fractures can be technically challenging because of the anterior angulation of the patellar tendon. This deformity is further exaggerated when the knee is flexed to gain access to the entry point during the infrapatellar technique. There is evidence that for the suprapatellar technique in the semi extended position, fracture reduction was more accurate in terms of angulation and translation in the coronal plane [4]. A significant complication of infrapatellar tibial nails is the incidence of anterior knee pain [11]. Previous studies have shown that there is either no significant difference or even reduction of anterior knee pain between the suprapatellar technique and the infrapatellar technique [5,6]. Further benefits of suprapatellar tibial nailing include that the incision is at a greater distance away from where commonly the soft tissue damage or open fracture wound occurs over the tibia [12], there is a decreased risk of patellar tendon damage and damage to the infrapatellar nerve [13]. An accurate nail entry point is key to the success of any tibial nailing. It has been shown that the centre of the entry point is just medial to the lateral tibial spine on the anteroposterior radiograph and immediately anterior to the articular margin on the lateral radiograph [3]. This entry point is constant and remains the same for all nailing procedures regardless of approach or instrumentation. Jones et al showed the nail insertion point is more accurate with the suprapatellar tibial nailing technique [6]. The reduced fluoroscopy time shown here may in part be due to the ease at which the entry point for a nail is achieved with the suprapatellar technique. Reviews of the suprapatellar tibial nailing technique also suggest that it is easier to achieve and maintain reduction of the fracture. Furthermore, intra-operative fluoroscopy is easier as the knee does not need to be repositioned for the anteroposterior and lateral radiographs. The knee can be kept in the original semi-extended position that was required for
Table 1 Radiation data for suprapatellar and infrapatellar intramedullary tibial nails. Radiation Time (secs)
Mean
Standard Deviation
Infrapatellar Suprapatellar
129.7 94.4
56.6 47.9
Dose DAP (cGY/cm2)
Mean
Standard Deviation
Infrapatellar Suprapatellar
53.6 38.2
34.2 26.7
3
reduction and nail insertion [14,15]. This decreases the time between anteroposterior and lateral radiographs. The Ionising Radiation (Medical Exposure) Regulations (IR(ME) R) 2000 is UK legislation which provides a framework intended to protect patients from the hazards associated with ionising radiation and advises that an awareness of the detrimental biological effects of ionising radiation is essential. Ionising radiation can directly or indirectly interact with DNA, disrupt water molecules and create reactive oxygen species leading to biological tissue damage. This can lead to cancerous and noncancerous diseases [8,9,16]. Intra-operative radiation exposure remains a significant concern to all theatre staff and limiting radiation has become an important topic in orthopaedics [7]. For the surgeon and other theatre staff, scattered radiation is the leading cause of exposure and directly relates to the patient’s DAP value. Therefore, reducing patient dose will directly translate in the reduced exposure of the theatre team. For patients undergoing procedures in theatre, the primary beam is the only source of radiation. There are several variables that will influence the final dose value. These can be divided into radiographer factors, surgical technique factors and patient factors. Patient factors, such as patient size, are understandably difficult to influence. Radiographer factors, such as intelligent collimation, limiting the use of magnification and using a reduced dose pulsed exposure where possible are dependent on the skill of the radiographer and team work with the surgeon. In general terms, surgeons can limit radiation exposure by minimising frequency of exposure and removing unnecessary surgical objects from the primary beam (exposure factors will change to try and penetrate metallic objects). However, there are many surgical technique factors that influence the final dose value. These include the positioning of the X-ray tube beneath the patient, minimising angles, patient positioning and limiting the use of supportive blocks. Therefore, it is possible the final radiation dose is increased in the infrapatellar technique compared to the suprapatellar technique because of aspects such as the use of supportive blocks and because of the difficulty in obtaining the anteroposterior and lateral radiographs, which increases the angle of the beam. A previous study by Sun et al. showed a decrease in fluoroscopy time for suprapatellar nails compared to infrapatellar nails in a total of 162 tibial nails [17]. However, that study did not look at fluoroscopic dose, and the fluoroscopic time they reported on was only a secondary outcome. Our study also shows that radiation dose is reduced during the suprapatellar technique which more accurately represents radiation exposure to the patient and theatre staff. Furthermore, our study set out to specifically answer the question surrounding radiation time and dose. The two major uncontrolled variables in the present study were: the skill and experience of the surgeon; and the difficulty of the fracture. Only seven consultant surgeons were included for analysis. They are experienced trauma surgeons working at a major trauma centre and have extensive experience in both suprapatellar and infrapatellar tibial nailing. This was done to rule out bias created by less experienced surgeons in either technique, or surgeons with more experience in one nailing approach. In addition, the first ten cases, representing initial learning curves in suprapatellar techniques for each consultant, (approximately six months per consultant) were excluded. Complex tibial nailing procedures and those procedures that involved treatment of further fractures were excluded to minimise these cases skewing the results. Conclusion This study aimed to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004
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and lower radiation doses when compared to the traditional infrapatellar technique. Both mean radiation time and mean radiation dose were lower in the suprapatellar group. Therefore, this study shows that amongst surgeons experienced in both supra and infrapatellar nailing techniques, the suprapatellar approach has significantly lower use of intra-operative fluoroscopy as measured by time and dose and thus potentially lower radiation exposure to the operating surgeon, assistants and patient. Funding None. Conflict of interest statement A. Trompeter has an R+D/Education consultancy contract with Stryker. However, no payment or work is related to this project in anyway. The remaining authors have no other conflicts of interest including no financial or personal relationships with other people or organisations that could inappropriately influence (bias) this work. References [1] Finkemeier C.G., Schmidt AH, Kyle RF, Templeman DC, Varecka TF. A prospective, randomized study of intramedullary nails inserted with and without reaming for the treatment of open and closed fractures of the tibial shaft. J Orthop Trauma 2000;14(March–April (3)). [2] Bong MR, Koval KJ, Egol KA. The history of intramedullary nailing. Bull NYU Hosp Dis 2006;64(3–4):94–7. [3] Zelle B, Boni G. Safe surgical technique: intramedullary nail fixation of tibial shaft fractures. Patient Saf Surg 2015;9:40.
[4] Tornetta 3rd P, Collins E. Semiextended position of intramedullary nailing of the proximal tibia. Clin Orthop Relat Res 1996;328(July):185–9. [5] Sanders RW, DiPasquale TG, Jordan CJ, Arrington JA, Sagi HC. Semiextended intramedullary nailing of the tibia using a suprapatellarapproach: radiographic results and clinical outcomes at a minimum of 12 months followup. J Orthop Trauma 2014;28(May (5)):24. [6] Jones M, Parry M, Whitehouse M, Mitchell S. Radiologic outcome and patientreported function after intramedullary nailing: a comparison of the retropatellar and infrapatellar approach. J Orthop Trauma 2014;28(May (5)):256–62. [7] Williams H, Widdowfield M, Cosson P. The radiographer’s multidisciplinary team role in theatre scenarios. Radiography 2015;21:165–71. [8] Tootell A, Szczepura K, Hogg P. An overview of measuring and modelling dose and risk from ionising radiation for medical exposures. Radiography 2014;20:323–32. [9] Department of Health. The ionising radiation (medical exposure) regulations 2000. IR(ME)R together with notes on good practice. London: TSO; 2000. . (Accessed January 2018) http://www.opsi.gov.uk/si/si2000/20001059.htm. [10] Stryker Orthopaedics, T2 tibial nailing system operative technique, 325 Corporate Dr. Mahwah NJ 07110, www.stryker.com (Accessed January 2018). [11] Court-Brown CM, Gustilo T, Shaw AD. Knee pain after intramedullary tibial nailing: its incidence, etiology, and outcome. J Orthop Trauma 1997;11 (February–March (2)):103–5. [12] Franke J, Hohendorff B, Alt V, Thormann U, Schnettler R. Suprapatellar nailing of tibial fractures–indications and technique. Injury 2016;47(February (2)):495–501. [13] Fu B. Locked META intramedullary nailing fixation for tibial fractures via a suprapatellar approach. Indian J Orthop 2016;50(May–June (3)):283–9. [14] Eastman J, Tseng S, Lo E, Li CS, Yoo B, Lee M. Retropatellar technique for intramedullary nailing of proximal tibia fractures: a cadaveric assessment. J Orthop Trauma 2010;24(November (11)):672–6. [15] Gelbke MK, Coombs D, Powell S, DiPasquale TG. Suprapatellar versus infrapatellar intramedullary nail insertion of the tibia: a cadaveric model for comparison of patellofemoral contact pressures and forces. J Orthop Trauma 2010;24(November (11)):665–71. [16] Cloutier D. Radiation exposure in orthopaedics. JBJS J Orthopaedics Phys Assist 2015;3(April (2)):5–9. [17] Sun Q, Nie X, Gong J, Wu J, Li R, Ge W, et al. The outcome comparison of the suprapatellar approach and infrapatellar approach for tibia intramedullary nailing. Int Orthop 2016;40(December (12))2611–7 Epub 2016 May 7.
Please cite this article in press as: M. Williamson, et al., Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing, Injury (2018), https://doi.org/10.1016/j.injury.2018.07.004