Interlocking screws placed with freehand technique and uni-planar image intensification: the “dip-stick” technique

Injury, Int. J. Care Injured 45S5 (2014) S21–S25

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Interlocking screws placed with freehand technique and uni-planar image intensification: the “dip-stick” technique Carlos A Finellia,*, Bruce H Ziranb, Alexandre Penna Torinic, Hélio Jorge A Fernandesd, Fernando Baldy dos Reisd Department of Orthopaedic Trauma Surgery, “Dr Carmino Caricchio” Tatuapé Municipal Hospital and Federal University of São Paulo (DOT–UNIFESP), São Paulo - Brazil The Hughston Clinic at Gwinnett Medical Centre, Atlanta, Georgia, USA c Department of Orthopaedic Trauma Surgery, “Dr Carmino Caricchio” Municipal Hospital, São Paulo – Brazil d Department of Orthopaedic Trauma Surgery, Federal University of São Paulo (DOT–UNIFESP), São Paulo, Brazil a

b

keywords

abstract

Intramedullary nail Distal locking Image intensification

Objective: To report our experience with a novel alternative method of freehand interlocking of intramedullary nails. This method requires the use of only anterior-posterior image intensification and an intramedullary guide wire to verify screw placement. Our results are compared with historical results in the literature. Methods: A total of 815 patients were treated using this technique from January 2008 to December 2012; 603 patients had fractures of the tibia and 212 had fractures of the femur. Results: The mean duration of surgery for tibial shaft fractures was 55.6 minutes (range 42-60 minutes) and that for fractures of the femur was 78 minutes (range 50-90 minutes). The mean time for each distal locking was 3.8 minutes (2.5-5.1 minutes), with 7.65 seconds of exposure to radiation during each block. Conclusions: The surgical technique is simple, easy and reproducible. Mean time of surgery and radiation exposure was less than that in the literature. A comparative study should be performed. © 2014 Elsevier Ltd. All rights reserved.

Introduction Locked intramedullary nailing has been utilised successfully as the treatment of choice for most diaphyseal fractures of the tibia and femur [1-6]. Results have been mostly excellent with high healing rates and good functional outcomes [7,8]. One of the main problems of interlocked nails is the placement of interlocking screws in the distal holes. Many different technologies and devices have been attempted in an effort to increase accuracy, and to decrease surgical times and radiation exposure. Although the proximal interlocking screws can be placed reliably through guides attached to the insertion jigs, the use of guides for the distal screw holes has had mixed results. One of the reasons for these mixed results is the known deformity of the nail during insertion through the medullary canal, which results in subtle bending and twisting, and thus makes fixed external guides less accurate. Also, adjustable external guides still require image intensification to obtain an accurate position relative to the nail, and therefore obviate their utility [9-14]. The freehand technique of interlocking screw placement is the current standard teaching in most residency programmes. Firstly, the “perfect circle” method is required to establish the * Corresponding author at: 86 Síria St, 1st floor, room #3, Tatuapé – São Paulo – SP - Brasil, CEP: 03063-000. Tel.: 5511-7620-2153. E-mail address: [email protected] (C.A. Finelli). 0020-1383/$ – see front matter © 2014 Elsevier Ltd. All rights reserved.

true axis of the interlocking screw hole relative to the bone. The surgeon must then place the drill point in the centre of the circle and drill in a co-axial fashion, through the nail and far cortex. After measurement, a screw is placed, but verification for length in the anterior-posterior image and for placement through the nail in the lateral is still recommended. In experienced hands, this method has been widely successful, but there are numerous unpublished and anecdotal reports of prolonged and complicated interlocking times [9,11,15,16]. We have developed a technique for placement of interlocking screws that utilises known relationships between the bone and nail, and incorporates use of a guide wire within the nail to assist and verify screw placement. This avoids the need for multiplanar imaging, prolonged imaging to find perfect circles, and the potential contamination of the image intensifier as it is moved repeatedly between anterior–posterior and lateral images [17]. The purpose of the present report was to describe the technique, present our preliminary results, and compare the method with methods in the literature. Methods A consecutive series of 815 patients treated with intra­ medullary nails was studied prospectively at the “Dr. Carmino Caricchio”-Tatuapé Municipal Hospital, from January 2008 to December 2012. Distal interlocking screws for each patient

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Fig. 3. (A) asymmetrically, (B) symmetrically. Fig. 1. Guide wire in the medullary cavity. (A) Anterior-posterior image, (B) Lateral image.

Fig. 4. The drill co-axial with the axis of the screw hole.

Fig. 2. Nail is centrally located.

were placed using the described technique. Inclusion criteria were diaphyseal fractures of the tibia or femur that were treated with reamed intramedullary nailing. Meta-diaphyseal fractures and very proximal and distal fractures were excluded. Outcome variables included total surgical time, time for interlocking screw placement, and radiation exposure. Patients were followed-up until healing using radiographic and clinical evaluation by the treating surgeon. As the purpose of the report is to evaluate an alternative method of placing interlocking screws, postoperative evaluation did not include formal outcome evaluations, but attention was noted for any associated event that may be related to the technique. Technique All aspects of intramedullary nailing used accepted principles and techniques. The described technique is for distal interlocking of the nail in which anterior-posterior and lateral imaging is traditionally used. In our technique, the guide wire is placed centrally in the medullary cavity (Figure 1). By so doing, the reaming and the subsequent nail are also centrally located (Figure 2). Instead of beginning with a lateral image, an anteriorposterior image perpendicular to the nail is used to determine the cephalad-caudad position of the interlocking hole. A perpendicular view of the nail is obtained by examining the scalloped defects of the nail where the interlocking holes have removed the normal side wall of the nail. They can also be seen as alterations in the image density. Perpendicularity is achieved when the image of the interlocking hole is symmetrically orientated around the nail (Figure 3).

Fig. 5. Drill passed across the nail.

The need for a true perpendicular view is two-fold. Firstly, the planar orientation of the nail to bone is established to help the surgeon centralise the drill. Secondly, it also establishes the axis of the interlocking hole in the axial plane. By aiming perpendicular to the nail and imaging direction, the drill should be co-axial with the axis of the screw hole (Figure 4). After verifying perpendicularity, the drill point is centralised in the coronal plane within this area. Using knowledge that the nail is centrally located in the canal, the surgeon uses proprioceptive and tactile feedback from the drill point to estimate the anterior and posterior cortical limits of the bone in the region of the most distal interlocking hole. The surgeon estimates the mid-point of the canal in the axial plane, which should correspond to the central location of the nail. The drill is then passed across the nail (but not through the far cortex) as seen on the anterior-posterior image (Figure 5). To verify the correct placement of the drill through the nail, the previously used guide wire that was withdrawn is now passed through the nail up to the interlocking hole. If the drill is properly positioned through the nail, the guide wire cannot pass distal to the interlocking hole and will have both a tactile sensation and an auditory metallic tapping of the guide wire against the drill bit and can be verified with an anterior-



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Fig. 8. The screw through the nail. Fig. 6. (A) The drill within the nail, (B) The drill not within the nail.

Fig. 9. External haemostat in relation to the insertion jig.

Fig. 7. The “dip-stick” movement.

posterior image. If the guide wire passes across the interlocking hole, it confirms that the drill point is not within the nail, and a corrective manoeuvre is required (Figure 6). As the passing of the guide wire has the manual and tactile characteristic of a dip stick used to measure oil levels, this acronym was chosen as a descriptor (Figure 7). Once the drill is verified to be through the nail, it is passed across the far cortex. Standard screw measurements and placement are performed and the guide wire is again used to verify that the screw is also through the nail (Figure 8). The location of the guide wire at the distal most screw hole is then set using an external haemostat placed on the guide wire, in relation to the insertion jig. (Figure 9) When the subsequent drilling and screw placement is performed the relative position of the haemostat from its reference should be equivalent to the distance between interlocking holes (Figure 10). Results A total of 815 patients (557 male, 258 female) with a mean age of 32 years (range 16-67 years) were treated with this technique. There were 212 fractures of the femur, and 603 fractures of the tibia. The technique was successful in all cases and lateral imaging was not needed in any of the 815 patients. Mean total operative time was 55.6 minutes for the tibia (range 42-60 minutes), and 78 minutes for the femur (range 50-90 minutes). The time to interlocking was measured from the time of drill insertion to that of screw placement. The mean interlocking time, per screw, was

Fig. 10. Equivalent position.

3.8 minutes (range 2.5-5.1 minutes). Mean radiation time was 7.65 second (range 5.6-9.3 seconds). This figure was measured directly from the cumulative time acquisition of the machine or the machine specification of time per image. There were no adverse events, fractures, or aborted pro­ cedures. In the early era of the technique, several (4) drill bits were broken without incident, and were retrieved when possible. The learning curve is relatively steep and this technique is now taught as standard procedure at the senior author’s (CAF) institution. Discussion There are several ongoing challenges in orthopaedic trauma and one of them appears to be distal interlocking. This aspect of nailing is considered by many to be rudimentary and common; however, there are always situations where interlocking becomes problematic. Also, if a surgeon does not routinely perform intramedullary nailing with freehand interlocking, the technique can eventually become more challenging. Although many guides

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have been developed, no single device has dominated the market. Clinical practice indicates that despite good efforts and intentions, even assistive devices are associated with problems; in fact, sometimes they make the efforts more challenging and frustrating. There are two other issues related to interlocking that are worthy of mention. The first issue is radiation exposure. Although the amount of absorbed radiation is relatively small, and radiation energy dissipates quickly as an inverse square function of the imaging emitter and collector, there is still the risk of cumulative lifetime radiation exposure, particularly for the operator whose hands are frequently within the described six feet of safe distance. Previous literature describes radiation dose associated with interlocked nailing with a range of 5 minutes. Our method is notably less than the described literature. There may well be a learning curve to the technique; however, the mean and range of exposure times indicate that the technique is safer than the standard freehand technique, and may be relatively easy to learn [16,18]. The second issue is contamination. Repeated swings of the C-arm from anterior-posterior to lateral are associated with an inherent risk of introducing contaminants during this phase of surgery. Recent studies have found that the drape of the C-arm becomes contaminated relatively rapidly. Furthermore, the position of the image intensifier in the lateral image is often a tight space and may bring a surgeon’s clean hand and equipment in proximity to a drape that was previously below sterile limits. Obviously, a new drape can always be placed over the C-arm during lateral positioning, but this would incur the costs of a new drape with each lateral view. In the traditional freehand technique, a typical scenario would be to start with an anteriorposterior view to centre the nail in the field, then a lateral view would be used to obtain the “perfect circles” and may require up to several lateral images. Once verified, localisation of the incision and multiple drill point placements are required, again with further radiation. The drill point is then advanced and verified to be through the nail. The image may then be switched back to anterior-posterior to verify drill position and measurement. Once the screw is placed, another lateral image is required to verify that the screw was placed through the nail [19]. In our technique, only an anterior-posterior view is required to initiate localisation, drilling and screw placement. The perpendicularity of the anterior-posterior image to the nail is very important because this establishes the reference perspective of the nail relative to the surgeon, bone, and drill/ screw components. The advantage of the retained guide wire is utilised as the verifying measure of both drill and nail placement. The initial guide wire placement, reaming and nail should be placed as centrally in the canal as possible. The surgeon must have the proprioceptive ability to then initiate drilling in the mid-section of the bone to approximate the nail hole. Small aberrations from an exact starting point were easy to rectify with small adjustments of the drill. For this reason, surgeons do not drill the far cortex until drill placement has been verified. If any difficulties are encountered, and perhaps during the early part of the learning curve, the surgeon can still utilise the lateral view; however, if the technique described is performed successfully, only a final and verifying lateral view of the screws is required. By mastering the new technique described in this paper, operative times and interlocking times were lower than those reported in the literature. There are inherent risks, such as causing a fracture due to stresses on the bone from a drill obliquely and tightly engaged across a nail hole, but the main risk was found to be drill breakage. The risk and concern of drill breakage should not be undervalued, with the subsequent time required to remove it, or

the risk of leaving it in place; however, the authors do not feel that this particular complication is severe enough to nullify the benefits of our technique. Conclusion This report describes the successful deployment of a technique used to drill and place screws across an intramedullary nail, using very limited radiation, only a few positional changes, and the tactile assistance of a retained guide wire. This technique may be particularly useful in more basic operating conditions where imaging has lower quality, is limited, or is unavailable. The technique may be modified and, certainly, more study is needed. This technique is easy to master, and is now taught as standard procedure in the authors’ training programme. Conflict of Interest Statement Bruce H Ziran has served as a consultant for Synthes and Acumed, has equity in Tekartis and Powers Medical Group. He has been a reviewer for JBJS, Clinical Orthopedics and Related Research, Journal of Orthopedic Trauma and Patient Safety in Surgery and is a committee member in OTA health policy. Fernando Baldy dos Reis has served as a consultant for Stryker. Carlos Augusto Finelli, Alexandre Penna Torini, Hélio Jorge A. Fernandes, Fernando Baldy dos Reis have no conflict of interest. References [1] Konstantinidis L, Papaioannou C, Hirschmüller A, Pavlidis T, Schroeter S, Südkamp NP, Helwig P. Intramedullary nailing of trochanteric fractures: central or caudal positioning of the load carrier? A biomechanical comparative study on cadaver bones. Injury 2013;44:784-90. [2] Hawi N, Liodakis E, Suero EM, Stuebig T, Citak M, Krettek C. Radiological outcome and intraoperative evaluation of a computer-navigation system for femoral nailing: A retrospective cohort study. Injury 2014;45:1632-6. [3] Ayalon OB, Patel NM, Yoon RS, Donegan DJ, Koerner JD, Liporace FA. Comparing femoral version after intramedullary nailing performed by trauma-trained and non-trauma trained surgeons: is there a difference? Injury 2014;45:1091-4. [4] Xue XH, Yan SG, Cai XZ, Shi MM, Lin T. Intramedullary nailing versus plating for extra-articular distal tibial metaphyseal fracture: a systematic review and meta-analysis. Injury 2014;45:667-76. [5] Jankovic A, Korac Z, Bozic NB, Stedul I. Influence of knee flexion and atraumatic mobilisation of infrapatellar fat pad on incidence and severity of anterior knee pain after tibial nailing. Injury 2013 ;44 (Suppl 3):S33-9. [6] Beingessner DM, Scolaro JA, Orec RJ, Nork SE, Barei DP. Open reduction and intramedullary stabilisation of subtrochanteric femur fractures: A retrospective study of 56 cases. Injury 2013;44:1910-5. [7] Bhandari M, Guyatt GH, Khera V, Kulkarni AV, Sprague S, Schemitsch EH. Operative management of lower extremity fractures in patients with head injuries. Clin Orthop Relat Res 2003;(407):187-98. [8] Karladani AH, Granhed H, Edshage B, Jerre R, Styf J. Displaced tibial shaft fractures: a prospective randomized study of closed intramedullary nailing versus cast treatment in 53 patients. Acta Orthop Scand 2000;71:160-7. [9] Krettek C, Mannss J, Könemann B, Miclau T, Schandelmaier P, Tscherne H. The deformation of small diameter solid tibial nails with unreamed intramedullary insertion. J Biomech 1997;30:391-4. [10] Krettek C, Könemann B, Nöschel F, Schandelmaier P, Blauth M, Tscherne H. Development and initial clinical use of an aiming device for distal boring in interlocking nailing without roentgen image intensifier for the unreamed tibial nail. Unfallchirug 1996;99:845-54. [11] Krettek C, Könemann B, Farouk O, Miclau T, Kromm A, Tscherne H. Experimental study of distal interlocking of a solid tibial nail: radiation-independent distal aiming device (DAD) versus freehand technique (FHT). J Orthop Trauma 1998;12:373-8. [12] Pardiwala D, Prabhu V, Dudhniwala G, Katre R. The AO distal locking aiming device: an evaluation of efficacy and learning curve. Injury 2001;32:713-8. [13] Gugala Z, Nana A, Lindsey RW. Tibial intramedullary nail distal interlocking screw placement: comparison of the free-hand versus distally-based targeting device techniques. Injury 2001;32(Suppl 4):SD21-5. [14] Barry TP. Radiation exposure to an orthopedic surgeon. Clin Orthop Relat Res 1984;(182):160-4. [15] Knudsen CJ, Grobler GP, Close RE. Inserting the distal screws in a locked femoral nail. J Bone Joint Surg Br 1991;73B:660-1. [16] Barrick EF. Distal locking screw insertion using a cannulated drill bit: technical



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