The role of MDCT in the preoperative planning of percutaneous screw fixation of lateral compression type 2 (LCII ) injuries.

Transcription

1 The role of MDCT in the preoperative planning of percutaneous screw fixation of lateral compression type 2 (LCII ) injuries. Poster No.: P-0053 Congress: ESSR 2016 Type: Scientific Poster Authors: A. Isaac, D. Dalili, J. Edwin, P. Harnett; London/UK Keywords: Anatomy, Bones, Trauma, CT-Quantitative, Image manipulation / Reconstruction, Percutaneous, Computer Applications-3D, Technical aspects, Decision analysis, Athletic injuries, Image verification DOI: /essr2016/P-0053 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 24

2 Purpose Percutaneous screw fixation of fractures of the Iliac wing, Young-Burgess "Lateral Compression-type II" pelvic fractures were first described in 2002, by A. Starr et al. The screws are placed in the corridor of bone between the anterior inferior iliac spine (AIIS) and the posterior superior iliac spine (PSIS), perpendicular to the fracture line. Intraoperative fluoroscopy imaging to estimate the LC2 screw length is difficult, as overlapping artefacts compromises views of the PSIS in the iliac-oblique view. The 'down the wing' view used to judge screw length of this corridor, is not accurate, as the exit point curves inferiorly and distally to the projected PSIS. Therefore the screw length is easily accidently over estimated. Long screws can penetrate the skin over the PSIS or cause a pressure ulcer. We describe a pre-operative templating method of the un-injured side that accurately estimates the AIIS to PSIS length. Page 2 of 24

3 Images for this section: Fig. 5: Intraoperative images: Traditional Open Reduction Methods amandaisaac Page 3 of 24

4 Fig. 6: Traditional Open Reduction Methods amandaisaac Page 4 of 24

5 Fig. 7: Percutaneous Fixation of LCII fractures amandaisaac Page 5 of 24

6 Fig. 3: Post operative imaging following percutaneous fixation amandaisaac Page 6 of 24

7 Fig. 4: Post operative imaging. Conventional radiographs to confirm the position of the screws. amandaisaac Page 7 of 24

8 Fig. 8: Entry point : AIIS easily visualised amandaisaac Page 8 of 24

9 Fig. 9: Medial and lateral corridor of the ilium are also easily visualised amandaisaac Page 9 of 24

10 Fig. 10: Exit point of the PSIS is poorly visualised. Technically it is very challenging to estimate the screw length when learning percutanaeous techniques amandaisaac Page 10 of 24

11 Methods and Materials Our study included eight CT scans performed on patients who underwent percutaneous fixation of their LC2 fractures using LC2 Screws. Using the MPR function on PACS, the 1mm axial images were reformatted on SECTRAPACS software. The static marker is dragged into the axis of the posterior ilium. This creates a oblique sagittal or an enface view of the AIIS to PSIS. The minimum distance just above the sciatic notch is measured, the maximum distance to the PSIS distance was measured, and a distance in the middle of these two was measured. One musculoskeletal radiologist and two orthopaedic surgeons independently recorded three measurements. The measurements were then compared to the results of the actual length of the LC2screws used. Iliac-oblique postoperative radiographs with high resolution of the PSIS were utilised to confirm the correct screw length. Page 11 of 24

12 Images for this section: Fig. 11: Planning the trajectory of the screws - London/UK Page 12 of 24

13 Fig. 12: Reformats on PACS: The static marker is dragged into the axis of the posterior ilium. This creates an oblique sagittal or an enface view of the AIIS to PSIS. amandaisaac Page 13 of 24

14 Fig. 13: Templating Method: three readings are obtained per side: maximum reading minimum reading and mid point reading. amandaisaac Page 14 of 24

15 Results Accuracy for clinician 1 (%) 97.8 Accuracy for clinician 2 (%) Accuracy for clinician 3(%) The mean accuracy amongst all three clinicians was 96.2% of actual screw used. (95 % C.I. ( %) or 4.3mm (95% C.I. 7.2mm - 1.3mm). The data was independently analysed using the Shapiro Wilk's test. There was excellent correlation between the measurements obtained from the MDCT reformats and the actual screws used. Page 15 of 24

16 Images for this section: Fig. 14: The results' table amandaisaac Page 16 of 24

17 Conclusion There was excellent correlation between the measurements obtained from the MDCT reformats and the actual screws used. The mean accuracy amongst all three clinicians was 96.2% of actual screw used. (95 % C.I. was % or 4.3mm-95% C.I. 7.2mm - 1.3mm). There were no screws that penetrated the posterior cortex, which could cause a sacral ulcer. Conscripting modern software, reformatting routine MDCT studies performed on trauma patients with LC2 fractures can be reliably used preoperatively. This avoids errors in measurements, improves fixation of the fracture, reducing intraoperative time and subsequently potential patient morbidity associated with incorrect length. Page 17 of 24

18 References Starr AJ, Walter JC, Harris RW, Reinert CM, Jones AL. Percutaneous screw fixation of fractures of the iliac wing and fracture-dislocations of the sacroiliac joint (OTA Types 61-B2.2 and 61-B2.3, or Young-Burgess "lateral compression type II" pelvic fractures). J Orthop Trauma 2002;16: Jacob AL, Messmer P, Stock KW, et al. Posterior pelvic ring fractures: closed reduction and percutaneous CT-guided sacroiliac screw fixation.cardiovasc Intervent Radiol 1997;20: Armack DB, Moed BR, McCarroll K, Freccero D. Accuracy of detecting screw penetration of the acetabulum with intra-operative fluoroscopy and computed tomography. J Bone Joint Surg [Am] 2001;83-A: A Parker P. Fluoroscopic and 3-D computed tomographic guidance in percutaneous fixation of acetabular fractures. J Bone Joint Surg [Am]2001;83-A: Starr AJ, Jones AL, Reinert CM, Borer DS. Preliminary results and complications following limited open reduction and percutaneous screw fixation of displaced fractures of the acetabulum. Injury 2001;32(Suppl 1): Routt ML Jr, Nork SE, Mills WJ. Percutaneous fixation of pelvic ring disruptions. Clin Orthop 2000;375: Routt ML Jr, Simonian PT, Mills WJ. Iliosacral screw fixation: early complications of the percutaneous technique. J Orthop Trauma1997;11: Borrelli J, Koval KJ Jr, Helfet DL. The crescent fracture: a posterior fracture dislocation of the sacroiliac joint. J Orthop Trauma 1996;10: Browner BD, Cole JD, Graham JM. Delayed posterior internal fixation of unstable pelvic fractures. J Trauma 1987;27: Matta J, Saucedo T. Internal fixation of pelvic ring fractures. Clin Orthop 1989;242: Mehlman C, DiPasquale T. Radiation exposure to the orthopaedic surgical team during fluoroscopy: how far away is far enough? J Orthop Trauma1997;11: Moed BR, Karges DE. Techniques for reduction and fixation of pelvic ring disruptions through the posterior approach. Clin Orthop 1996;329: Routt ML Jr, Kregor PJ, Simonian PT, Mayo KA. Early results of percutaneous iliosacral screws placed with the patient in the supine position. J Orthop Trauma 1995;9: McLaren A. Long-term pain and disability in relation to residual deformity after displaced pelvic ring fractures. Can J Surg 1990;33: Henderson R. The long-term results of non-operatively treated major pelvic disruptions. J Orthop Trauma 1989;3:41-7. Kellam JF, McMurtry RY, Paley D, Tile M. The unstable pelvic fracture: operative treatment. Orthop Clin North Am 1987;18: Page 18 of 24

19 17. Routt ML Jr, Simonian PT, Swiontkowski MF. Stabilization of pelvic ring disruptions. Orthop Clin North Am 1997;28: Barei DP, Bellabarba C, Mills WJ, Routt ME Jr. Percutaneous management of unstable pelvic ring disruptions. Injury 2001;32(Suppl 1): Barei DP, Bellabarba C, Mills WJ, Routt ME Jr. Percutaneous management of unstable pelvic ring disruptions. Injury 2001;32(Suppl 1): Ebraheim NA, Mermer M, Xu R, Yeasting RA. Radiological evaluation of S1 dorsal screw placement. J Spinal Disord 1996;9: Shuler TE, Boone DC, Gruen GS, Peitzman AB. Percutaneous iliosacral screw fixation: early treatment for unstable posterior pelvic ring disruptions. J Trauma 1995;38: Gay SB, Sistrom C, Wang GJ, et al. Percutaneous screw fixation of acetabular fractures with CT guidance: preliminary results of a new technique. AJR Am J Roentgenol 1992;158: Jacob AL, Suhm N, Kaim A, et al. Coronal acetabular fractures: the anterior approach in computed tomography-navigated minimally invasive percutaneous fixation. Cardiovasc Intervent Radiol 2000;23: Page 19 of 24

20 Personal Information Dr Amanda Isaac: Consultant Musculoskeletal Radiologist, Guy's and St Thomas' NHS Foundation Trust, London, UK Senior Clinical Lecturer, Kings College London, UK Dr Danoob Dalili: Specialist Registrar in Clinical Radiology, Imperial College Healthcare NHS Foundation Trust Mr John Edwin: Specialist Registrar in Orthopaedic Surgery, Kings College Hospital NHS Foundation Trust, London, UK Mr Paul Harnett, Consultant Orthopaedic Surgeon, Kings College Hospital NHS Foundation Trust, London, UK Page 20 of 24

21 Images for this section: Fig. 15: Guy's and St Thomas's NHS Foundation Trust amandaisaac Page 21 of 24

22 Fig. 16: KCL - London/UK Page 22 of 24

23 Fig. 17: Imperial college - London/UK Page 23 of 24

24 Fig. 18: KCH - London/UK Page 24 of 24