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The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 1 | Pages 76 - 81
1 Jan 2005
Pajarinen J Lindahl J Michelsson O Savolainen V Hirvensalo E

We treated 108 patients with a pertrochanteric femoral fracture using either the dynamic hip screw or the proximal femoral nail in this prospective, randomised series. We compared walking ability before fracture, intra-operative variables and return to their residence. Patients treated with the proximal femoral nail (n = 42) had regained their pre-operative walking ability significantly (p = 0.04) more often by the four-month review than those treated with the dynamic hip screw (n = 41). Peri-operative or immediate post-operative measures of outcome did not differ between the groups, with the exception of operation time. The dynamic hip screw allowed a significantly greater compression of the fracture during the four-month follow-up, but consolidation of the fracture was comparable between the two groups. Two major losses of reduction were observed in each group, resulting in a total of four revision operations. Our results suggest that the use of the proximal femoral nail may allow a faster postoperative restoration of walking ability, when compared with the dynamic hip screw


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_4 | Pages 13 - 13
3 Mar 2023
Rohra S Sinha A Kemp M Rethnam U
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Background. Dynamic Hip Screw (DHS) is the most frequently used implant in management of intertrochanteric femoral fractures. There is a known statistical relationship between a tip-apex distance (TAD) >25mm and higher rate of implant failure. Our aim was to analyse all DHS procedures performed in our trust from seventeen months and compare their TAD values to the acceptable standard of ≤25mm. Methods. All patients undergoing DHS between April 2020-August 2021 were identified from our theatre system. Additionally, those presenting to hospital with implant failures were included. Patient demographics, date of surgery, fracture classification (AO) and date/mode of failure were recorded. Intraoperative fluoroscopy images were reviewed to calculate TAD, screw location and neck shaft angles by two independent observers. Results. 215 patients were identified, five of which were excluded due to inadequate fluoroscopy. Failure was seen in 3.3% of the cohort (n=7), of which 71.4% had an unacceptable TAD. In total, 21 patients (10%) had TAD >25mm, of whom 12 had superiorly and 15 had posteriorly placed screws. There were no failures in patients with a TAD of <20mm whereas a TAD >30mm had 50% failure rate. Conclusion. This audit reinforces the importance of aiming for a low TAD (preferably <20mm) intraoperatively. It is also desirable to avoid superiorly and significantly posteriorly placed screws. Implications. Complex hip revision surgery in the elderly bears substantial financial implications to the NHS and, more importantly, causes prolonged morbidity to the patient. Adhering to established standards will ensure reduced implant failure and best patient care


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 70 - 70
1 Mar 2006
Waters T Gibbs D Powles D Dorrell J
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We present the results of a technique of dynamic hip screw insertion through a very small incision, typically 2.5cm. Method: The technique is performed using a standard dynamic hip screw set and requires no additional equipment. We compared the results to those of an age and sex matched group who had undergone the operation through a traditional approach. We compared the time spent in theatre, the pre and post-operative haemoglobin concentration, haematocrit, and prevalence of wound infection. Results: 13 consecutive intertrochanteric hip fractures were treated with a dynamic hip screw and 4-hole plate by one surgeon using the percutaneous technique. There were 9 females and 4 males with a mean age of 84 years (range 62 to 96 years). The mean post-operative drop in haemoglobin concentration in the percutaneous group was 2.2 g/dl (range 0 to 4.4 g/dl) compared to 3.5 g/dl (range 1.2–5.4) in the control group (p=0.014). The mean haematocrit drop was 0.07 (range 0 to 0.12) in the percutaneous group compared to 0.10 (range 0.03 to 0.17) in the control group (p=0.017). The mean theatre time with the percutaneous technique was 57 minutes (range 40–75 minutes) and in the control group, 60 minutes (range 30–95). There were no wound problems. Conclusion: To our knowledge, this technique has not been previously reported. The percutaneous technique offers a better clinical outcome at no extra expense and warrants further evaluation in a larger study


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 5 | Pages 616 - 621
1 May 2011
O’Neill F Condon F McGloughlin T Lenehan B Coffey JC Walsh M

We biomechanically investigated whether the standard dynamic hip screw (DHS) or the DHS blade achieves better fixation in bone with regard to resistance to pushout, pullout and torsional stability. The experiments were undertaken in an artificial bone substrate in the form of polyurethane foam blocks with predefined mechanical properties. Pushout tests were also repeated in cadaveric femoral heads. The results showed that the DHS blade outperformed the DHS with regard to the two most important characteristics of implant fixation, namely resistance to pushout and rotational stability. We concluded that the DHS blade was the superior implant in this study


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_II | Pages 173 - 173
1 Feb 2004
Tsarouhas T Poulilios A Nicolopoulos F Papadopoulos F Bakali S Gevezes E
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Aim: The addition of the Trochanteric Support Plate (TSP) to the Dynamic Hip Screw is a very effective way of treatment of the reverse oblique fractures of the proximal femur. It secures the stabilisation of the greater trochanter as well as it prevents from the lateral transposition of the greater trochanter during the impaction of the fracture postoperatively. Method: The reversed oblique fractures of the proximal femur is a group of unstable fractures characterised by a fracture line going from lateral distal to medial proximal of the lesser trochanter. The OTA classifies them as 3.1 A3 fractures and subdivides them in 31 A3.1, 31 A3.2. and 31 A3.3 groups. We operated on 1535 fractures of the hip in our Department during Jan. 1998 to Dec. 2002, 997 of them were introchanteric or subtochanteric fractures. Among them there were 35 reversed oblique fractures. Five of them were fixed by an interlocking nail (gamma nail), nire of them by a Dynamic Hip Screw and twenty one by the Dynamic Hip Screw with the addition of a Trochanteric Support Plate. We surveyer the duration of the operation as well as the duration of the operation as well as the radiation time in each of them. Results: Five out of nine fractures treated by the dynamic hip screw alone failed and were reoperated one out of four fractures treated by the gamma nail developed a pseudarthrosis and was reoperated, too. Only one out of twenty one fractures treated by the dynamic hip screw with the addition of the trochanteric support plate (TSP) failed because of inadequate reduction of the fracture and wrong placement of the screw. Conclusion: The addition of the Trochanteric Support Plate to the Dynamic Hip Screw is a more satisfactory way of treatment of the reversed oblique fractures of the proximal femur when compared to the other methods of osteosynthesis. The advantages are: lower percentage of complications, easy application of the plate and short radiation time. However the result may be disastrous in case of a bad reduction of the fracture and a wrong placement of the screw


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 4 - 4
1 Jan 2011
McCarthy MJH Long R Weston R Gheduzzi S Keenan J Miles A
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Objectives: To compare the biomechanical properties of lag screw insertion in a laboratory model. Two blades, the Synthes Dynamic Helical Hip Screw (DHHS) and Proximal Femoral Nail Antirotation (PFNA), and two screws, the Synthes Dynamic Hip Screw (DHS) and Stryker Gamma 3 lag screw, were compared. Setting: Orthopaedic biomechanics laboratory. Design: Insertion testing was carried out in high and low density polyurethane foam mounted and attached to a Zwick Roell Amsler Hydrowin. Outcome Measures: The axial load and torque during insertion of the implants was measured. Results: The force required to insert the DHHS and PFNA blades was greater than the DHS and Gamma 3 screws into both low and high density foam. The force required to insert the DHHS and PFNA blades into high density foam was greater than low density foam. The torque required to insert the DHHS and PFNA blades into high density foam was less than that to insert the DHS and Gamma 3 screws. The torque required to insert the DHS and Gamma 3 screws into low density foam was less than the DHHS and PFNA blades. The torque during insertion of the DHHS and PFNA blades seemed to be independent of foam density. Conclusions: The insertional properties of blades are significantly different to screws and this may have clinical importance


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_I | Pages 82 - 82
1 Jan 2004
Shah N AMMA M Sherman K Phillips R Viant W
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Aims: Dynamic hip screw (DHS) is a common implant used for extracapsular fracture neck of femur. Accurate placement of the guide wires for the DHS insertion is the most important surgical step. In order to improve precision and accuracy of the guide wire placement, Computer Assisted Orthopaedic Surgery System (CAOSS) was used , which was developed at the University of Hull. Methods: CAOSS helps in surgical planning and aid surgeons for accurate guide wire placement into femoral neck. After fracture reduction, intra-operative computer based surgical planning was performed using one fluoroscopic image in two planes each. A trajectory obtained thus helped surgeon to place a guide wire along with the required course under the computer guidance. Results: CAOSS system was used on 11 patients for guide wire placement. Intra-operative fluoroscopic images of all the patients showed accurate position of the guide wire both in AP and lateral planes. In theory only 4 fluoroscopic images are required during this surgical procedure in total. But in practice, more than 4 were required depending upon the experience of the radiographer. None of the patient had any intra-operative complication. Conclusions: The computer aided surgery was found to be safe, accurate and reliable for guide wire placement for dynamic hip screw insertion


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 377 - 377
1 Mar 2004
Shah N Phillips R Mohsen A Sherman K
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Aims: Dynamic hip screw (DHS) is a common implant used for extracapsular fracture neck of femur. Accurate placement of the guide wires for the DHS insertion is the most important surgical step. In order to improve precision and accuracy of the guide wire placement, Computer Assisted Orthopaedic Surgery System (CAOSS) was used which was developed at the University of Hull. Early clinical experience in 14 cases is presented. Methods: CAOSS helps in surgical planning and aid surgeons for accurate guide wire placement into femoral neck. After fracture reduction, intraoperative computer based surgical planning was performed using one ßuoroscopic image in two planes each. A trajectory obtained thus helped surgeon to place a guide wire along with the required course under the computer guidance. Results: CAOSS system was used on 11 patients for guide wire placement. Intraoperative ßuoroscopic images of all the patients showed accurate position of the guide wire both in AP and lateral planes. Only 4 ßuoroscopic images were required during the surgical procedure in total, both pre and post guide wire insertion. Conclusions: The computer aided surgery used in guide wire placement for dynamic hip screw insertion proves to be accurate and reliable. It also reduces ionisation radiation exposure to the surgeon, patients and theatre personnel


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 185 - 185
1 Mar 2006
Espierrez J Cuenca J Martaanez F Garcia-Erce J Martinez A
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Background: To determine patients clinical and haematological characteristics that could affect the use of blood and infection incidence with hip fractures (HF) treated with a dynamic hip screw (DHS). Patients and Methods: A retrospective study of all the HF patients during 5 years (January1995- December1999) who were treated with a dynamic hip screw (DHS ïf’, Synthes-Stratec, Oberdof, Switzerland) at one unique university hospital. No patient was excluded. Age, gender, elapsed time, anaesthesia risk (ASA clasification), type of HF (internationalAO classification), transfusion procedure and the total used; haemoglobin (Hb) at days 0 (incoming to urgency service) and first postoperative (POD ï€1) were examined. We also analyzed the infection incidence (CDC criteria), place and severity. The statistical univariate analysis included Student’s t-test for numeric variables and Pearson’s chi-squared test for string variables. There was considered to be a statistically significant difference (SSD) when p< 0.05. A multivariate stepwise logistic regression model was used. Results: Three hundred and one patients with HF were studied. 125 A1 and 176 A2, according to the AO classification. Male/female ratio: 76/225 (25.2%/74.8%); age 78.97 years old (range: 23–104); ASA: I 53 (17.6%); II 97 (32.2%); III 138 (45.8%) and IV 13 (4.3%). Hb Values on the day of admission: 128.7 g/L (range: 81.7–176.7) and POD ï€1: 101 g/L (range: 54.7–150.7). 186 (61.8%) patients were transfused with an average 1.42 red cell concentrate (range: 0–6). 89 (29.6%) had an infection diagnosis: 79 (26.2%) urinary tract infection (UTI), 7 (2.3%) pneumonia and 8 (2.7%) superficial wound. 18 (6%) died in the first month. At univariant study of transfusion act, the transfused patients were older (p< 0.001), suffered more infections (p:0.019), more UTI (p:0.003), had lower Hb day 0 (p< 0.001) and POD ï€1(p< 0.001). When analyze the infection, the patients were older (p< 0.001), had higher ASA (p:0.019), lower Hb at day0 (p< 0.026), longer stay (p< 0.001), were more transfused (p:0.019), and received more transfusions (p:0.004). The logistic regression analysis identified only the type of HF, the age and the Hb level (p< 0.05) as independent predictors of transfusion. Comments: In patients with HF the Hb is the most important predictor of blood transfusion, and it is associated with a higher rate of post surgical infection and longer hospital stays. These complications may be explained by the possible inmunomodulation effect of allogenic blood transfusion


The Journal of Bone & Joint Surgery British Volume
Vol. 68-B, Issue 4 | Pages 557 - 560
1 Aug 1986
Esser M Kassab J Jones D

In a randomised prospective trial 98 elderly women with trochanteric fractures of the femur were treated with either a 135 degrees Jewett nail-plate or a 135 degrees Dynamic hip screw. The results at six weeks, three months and six months were statistically analysed. There were no significant differences in the two groups with regard to pain, length of hospital stay, morbidity or mortality. Although operative difficulties and open reduction were more common with the Dynamic hip screw, at the end of six months more patients in this group were mobile and there was significant radiological evidence of better compression without loss of fixation


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 70 - 70
1 Mar 2006
Subramanian K Puranik G Ali M Sahni V
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Introduction: Dynamic Hip Screw (DHS) fixation is one of the most common orthopaedic surgical procedures. Tip Apex Distance (TAD) is a well recognised method of evaluating the screw position of the DHS. We studied the adequacy of fixation of DHS by assessing TAD and type of reduction. Materials and Methods: We selected a random cohort of 102 patients who had DHS fixation and had the requisite clinico-radiologic data. TAD is defined as sum of the distance, in millimeteres, from the tip of the lag screw to the apex of femoral head, as measured on AP radiograph and Lateral radiograph, after correction has been made for radiological magnification. Tip apex distance of 25 mm or less is considered as good, 26–30mm as acceptable, 31–35mm as poor and more than 35mm as unacceptable. Quality of reduction was assessed as per Sernbo. Good, if alignment was normal on AP and maximum 20 degrees angulation on lateral radiograph and less than 4mm of displacment of any fragment. To be labelled acceptable, a reduction had to meed the criteria of a good reduction with respect to either alignement or displacement, but not both. A poor reduction met neither. Results: Mean TAD in our series was 24mm. (9.84 – 37.6). Our of this 58.82% were 25mm or less indicating good, 25.49% of them were 26–30mm indicating acceptable, 8.82% were 30–35mm indicating poor and 6.8% were more than 35mm indicating unacceptable. 39.21% patients had good reduction. 43.13% had acceptable reduction and 17.64% had poor reduction. Conclusion: This study shows that only 58.82% of all patients having DHS fixation had good placement of the fixation device and only 39.21% had a good reduction. We conclude that complacency must not set in on DHS fixation and that we must endeavour for good reduction and placement in as many cases as possible


The placement of the guide wire in the dynamic hip screw operation can be a challenging task to the trauma surgeon. Complications can arise related to incorrect guide wire entry point, making wrong tracks, or even accepting an unsatisfactory lag screw placement. Insisting to optimise the guide wire position can lead to increase in operation and radiation exposure times. A new non-invasive technique is described to assist precision placement of the guide wire in the dynamic hip screw fixation of the neck of femur fractures using no more than a size A4 plain folded paper and a non-permanent marker pen. The new non-invasive “no high tech” method can help the trauma surgeons to shorten the operation time and reduce the radiation exposure time needed to place the guide wire in the dynamic hip screw fixation of the neck of femur fractures


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_9 | Pages 38 - 38
1 May 2017
Ertem F Havıtçıoğlu Ç Erduran M Havıtçıoğlu H
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Background. The advantages of treatment by open reduction and internal fixation for intertrochanteric fractures of the proximal femur have been well known for several decades. Failure of fixation can result in revision surgery, prolonged inpatient stay and has major socio-economic consequences. There are many new devices on the market to help deal with this problem. Expandable hip screw (EHS) is one such device, which is an expanding bolt that may offer superior fixation in osteoporotic bone compared to the standard dynamic hip screw (DHS) type device. Methods. Static axial compression tests with elastic deformation of the specimens were performed with a crosshead speed of 10 mm/min to determine stiffness of testing was performed with 3 cycles from 0 N to 250 N, 3 cycles from 0 N to 500 N, 3 cycles from 0 N to 750 N and 3 cycles from 0 N to 1000 N with a holding time of 10 s per test cycle. Displacement control was apply the pullout strength with a velocity of 1mm/sec. The ability to resist rotation about the axis of a lag screw is of critical importance particularly when the fracture line is perpendicular, or nearly perpendicular, to the femoral neck. Implants were subjected to a rotation of 1 degree/sec and peak torque values were recorded. Results. The mean axial cyclic loading DHS showed higher stiffness value than EHS. The mean stiffness achieved at pullout test in the EHS and DHS groups were 587.8N/mm and, 334.1N/mm respectively (p<0.05). The peak torque for the EHS device was significantly greater than the torque for the DHS with torque values of 4.56 Nm/degree and 2.97 Nm/degree, respectively (p<0.05). Conclusions. The EHS device demonstrated superior resistance to pullout and torsion greater loads compared to the DHS in an unstable fracture model. However, axial cyclic loading demonstrate lower strength, by optimising the size of device will perform. Level of Evidence. Level 5


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 79 - 79
1 Apr 2018
van Duren B Wescott R Sugand K Carrington R Hart A
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Background. Hip fractures affect 1.6 million people globally per annum, associated with significant morbidity and mortality. A large proportion are extracapsular neck of femur fractures, treated with the dynamic hip screw (DHS). Mechanical failure due to cut-out is seen in up to 7% of DHS implants. The most important predictor of cut-out is the tip-apex distance (TAD), a numerical value of the lag screw”s position in the femoral head. This distance is determined by the psychomotor skills of the surgeon guided by fluoroscopic imaging in theatre. With the current state of surgical training, it is harder for junior trainees to gain exposure to these operations, resulting in reduced practice. Additionally, methods of simulation using workshop bones do not utilise the imaging component due to the associated radiation risks. We present a digital fluoroscopy software, FluoroSim, a realistic, affordable, and accessible fluoroscopic simulation tool that can be used with workshop bones to simulate the first step of the DHS procedure. Additionally, we present the first round of accuracy tests with this software. Methods. The software was developed at the Royal National Orthopaedic Hospital, London, England. Two orthogonally placed cameras were used to track two coloured markers attached to a DHS guide-wire. Affine transformation matrices were used in both the anterior-posterior (AP) and cross table lateral (CTL) planes to match three points from the camera image of the workshop bone to three points on a pre-loaded hip radiograph. The two centre points of each marker were identified with image processing algorithms and utilised to digitally produce a line representing the guide-wire on the two radiographs. To test the accuracy of the system, the software generated 3D guide-wire apex distance (GAD) (from the tip of the guide-wire to a marker at the centre of calibration) was compared to the same distance measured with a digital calliper (MGAD). In addition, the same accuracy value was determined in a simulation scenario, from 406 attempts by 67 medical students. Results. The median absolute inaccuracy of FluoroSim with 270 measurements was 3.35mm (IQR = [1.15mm, 6.53mm]). The absolute inaccuracy showed a graded increase the further away the tip of the guide-wire was from the centre of calibration; MGAD ≤10mm, median absolute inaccuracy = 1.53mm; MGAD 10mm<x≤20mm, median absolute inaccuracy = 4.97mm; MGAD >20mm, median absolute inaccuracy = 7.23mm. Comparison between all three groups reached significance (p < 0.001). In a simulation scenario with medical students, FluoroSim had a significantly greater median absolute inaccuracy of 4.79mm compared to the testing scenario (p < 0.001). Conclusion. FluoroSim is a safe and inexpensive digital imaging adjunct to workshop bones simulation. To our knowledge this technology has not been explored in the context of DHS simulation, and has the potential to be extended to other orthopaedic procedures


The Journal of Bone & Joint Surgery British Volume
Vol. 72-B, Issue 5 | Pages 794 - 796
1 Sep 1990
Richards R Evans G Egan J Shearer

We compared, under laboratory conditions, the resistance to cutting out of the AO dynamic hip screw and the Pugh sliding nail. The mean load at cut out, adjusted for bone strength, was 70% greater for the Pugh sliding nail. The reasons for this difference are discussed


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 8 | Pages 1073 - 1078
1 Aug 2008
Little NJ Verma V Fernando C Elliott DS Khaleel A

We compared the outcome of patients treated for an intertrochanteric fracture of the femoral neck with a locked, long intramedullary nail with those treated with a dynamic hip screw (DHS) in a prospective randomised study. Each patient who presented with an extra-capsular hip fracture was randomised to operative stabilisation with either a long intramedullary Holland nail or a DHS. We treated 92 patients with a Holland nail and 98 with a DHS. Pre-operative variables included the Mini Mental test score, patient mobility, fracture pattern and American Society of Anesthesiologists grading. Peri-operative variables were anaesthetic time, operating time, radiation time and blood loss. Post-operative variables were time to mobilising with a frame, wound infection, time to discharge, time to fracture union, and mortality. We found no significant difference in the pre-operative variables. The mean anaesthetic and operation times were shorter in the DHS group than in the Holland nail group (29.7 vs 40.4 minutes, p < 0.001; and 40.3 vs 54 minutes, p < 0.001, respectively). There was an increased mean blood loss within the DHS group versus the Holland nail group (160 ml vs 78 ml, respectively, p < 0.001). The mean time to mobilisation with a frame was shorter in the Holland nail group (DHS 4.3 days, Holland nail 3.6 days, p = 0.012). More patients needed a post-operative blood transfusion in the DHS group (23 vs seven, p = 0.003) and the mean radiation time was shorter in this group (DHS 0.9 minutes vs Holland nail 1.56 minutes, p < 0.001). The screw of the DHS cut out in two patients, one of whom underwent revision to a Holland nail. There were no revisions in the Holland nail group. All fractures in both groups were united when followed up after one year. We conclude that the DHS can be implanted more quickly and with less exposure to radiation than the Holland nail. However, the resultant blood loss and need for transfusion is greater. The Holland nail allows patients to mobilise faster and to a greater extent. We have therefore adopted the Holland nail as our preferred method of treating intertrochanteric fractures of the hip


The Journal of Bone & Joint Surgery British Volume
Vol. 75-B, Issue 5 | Pages 789 - 793
1 Sep 1993
Radford P Needoff M Webb J

We made a randomised prospective comparison of the Dynamic Hip Screw and the Gamma locking nail for the internal fixation of 200 petrochanteric femoral fractures in elderly patients. There was less intraoperative blood loss and a lower rate of wound complications in the patients treated by the Gamma nail. They had, however, a high incidence of femoral shaft fracture which we relate in part to implant design. We do not recommend the use of the Gamma nail for these fractures


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 80 - 80
1 Apr 2018
Sugand K van Duren B Wescott R Carrington R Hart A
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Background. Hip fractures cause significant morbidity and mortality, affecting 70,000 people in the UK each year. The dynamic hip screw (DHS) is used for the osteosynthesis of extracapsular neck of femur fractures, a procedure that requires complex psychomotor skills to achieve optimal lag screw positioning. The tip-apex distance (TAD) is a measure of the position of the lag screw from the apex of the femoral head, and is the most comprehensive predictor of cut-out (failure of the DHS construct). To develop these skills, trainees need exposure to the procedure, however with the European Working Time Directive, this is becoming harder to achieve. Simulation can be used as an adjunct to theatre learning, however it is limited. FluoroSim is a digital fluoroscopy simulator that can be used in conjunction with workshop bones to simulate the first step of the DHS procedure (guide-wire insertion) using image guidance. This study assessed the construct validity of FluoroSim. The null hypothesis stated that there would be no difference in the objective metrics recorded from FluoroSim between users with different exposure to the DHS procedure. Methods. This multicentre study recruited twenty-six orthopaedic doctors. They were categorised into three groups based on the number of DHS procedures they had completed as the primary surgeon (novice <10, intermediate 10≤x<40 and experienced ≥40). Twenty-six participants completed a single DHS guide-wire attempt into a workshop bone using FluoroSim. The TAD, procedural time, number of radiographs, number of guide-wire retires and cut-out rate (COR) were recorded for each attempt. Results. A significant construct effect was seen for TAD and COR between novice and other users (p < 0.05). The intermediate and experienced users were not significantly different for these metrics. For all other metrics, experienced users had the highest score, contrary to expectation. Conclusion. FluoroSim was able to separate novice users from other cohorts for the two clinically significant outcome metrics. We can therefore partially reject the null hypothesis as construct validity was present for TAD and COR. We have demonstrated that FluoroSim has the potential to be a useful adjunct when learning the psychomotor skills needed for the DHS procedure away from theatre


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_3 | Pages 81 - 81
1 Apr 2018
Sugand K Wescott R van Duren B Carrington R Hart A
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Background. Training within surgery is changing from the traditional Halstedian apprenticeship model. There is need for objective assessment of trainees, especially their technical skills, to ensure they are safe to practice and to highlight areas for development. In addition, due to working time restrictions in both the UK and the US, theatre time is being limited for trainees, reducing their opportunities to learn such technical skills. Simulation is one adjunct to training that can be utilised to both assess trainees objectively, and provide a platform for trainees to develop their skills in a safe and controlled environment. The insertion of a dynamic hip screw (DHS) relies on complex psychomotor skills to obtain an optimal implant position. The tip-apex distance (TAD) is a measurement of this positioning, used to predict failure of the implant. These skills can be obtained away from theatre using workshop bone simulation, however this method does not utilise fluoroscopy due to the associated radiation risks. FluoroSim is a novel digital fluoroscopy simulator that can recreate digital radiographs with workshop bone simulation for the insertion of a DHS guide-wire. In this study, we present the training effect demonstrated on FluoroSim. The null hypothesis states that no difference will be present between users with different amounts of exposure to FluoroSim. Methods. Medical students were recruited from three London universities and randomised into a training (n=23) and a control (n=22) cohort. All participants watched a video explanation of the simulator and task and were blinded to their allocation. Training participants completed 10 attempts in total, 5 attempts in week one, followed by a one week wash out period, followed by 5 attempts in week 2. The control group completed a single attempt each week. For each attempt, 5 metrics were recorded; TAD, procedural time, number of radiographs, number of guide-wire retires and cut-out rate (COR). Results. No significant difference was present for any metric between the groups at baseline; randomisation had produced heterogeneous groups minimising selection bias. Intragroup training effect (comparison of initial and last attempt) was significant for all metrics in the training group (p < 0.05) but for no metrics in the control group. The intergroup training effect (comparison of training group attempt ten to control group attempt ten) was present for procedural time, number of radiographs and number of guide-wire retries (p < 0.05). Significance was not reached for TAD and COR. Conclusion. FluoroSim shows skill acquisition with repeat exposure, so the null hypothesis can be rejected. This study has demonstrated the merits of FluoroSim as a training adjunct for psychomotor skill development in a DHS setting


Introduction: Many patients admitted to acute fracture units with femoral neck fractures are frail and elderly, dehydrated and malnourished, often with associated medical conditions. Surgery may be delayed for investigation, prolonged management and inadequate review of their medical problems, leading to clinical deterioration with poor outcome. Local anaesthetic techniques have been described for intracapsular fractures. We describe a technique effective for the treatment of the more difficult extracapsular type. Aims: To provide a safe and effective technique using local anaesthetic and sedation, for the insertion of a dynamic hip screw in high risk elderly patients with extracapsular femoral neck fractures. Method: Fifty elderly patients who sustained an inter-trochanteric fracture of their femoral neck underwent dynamic hip screw insertion under local anaesthetic and sedation. These patients were medically assessed following admission, all were ASA grade 4, had an additional medical condition (recent MI, CVA, chest infection, aortic stenosis) and were deemed unfit for either general or spinal anaesthesia. All patients not fit for traditional anaesthetic methods were assessed for their suitability for operation under LA, consented and placed on the next available theatre list. A femoral nerve block was performed, with the aid of a nerve stimulator for accurate location, in the anaesthetic room; skin and periosteal infiltration was performed using a 22g spinal needle, with caution to include the distribution of the lateral cutaneous nerve. The patient was then placed on the fracture table and mild sedation (Ketamine, Diazemul, 02/N20) was administered, titrated against the patients requirements. The fracture was reduced using traction and internal rotation, and the DHS inserted. Local Anaesthetic:Infiltration; * 20mls O.25% marcaine/1 in 200,000 adrenaline diluted to 40mls with sterile water. (30mls used with 10mls reserved) * 20mls 1% lidocaine diluted in 40mls of sterile water. (10mls used for skin). Local Anaesthetic femoral nerve block; * 10mls 0.25% plain marcaine. The combined amount of local anaesthetic used is well below safe limits recommended by the World Federation of Societies of Anaesthesiologists. Conclusion: This technique is a safe, simple and effective method of allowing high risk, medically unfit patients to undergo surgery. It reduces operative bleeding and postoperative analgesia requirements, no peri-operative deaths occurred and one patient had evidence of post operative tachycardia that settled within 12 hours