The cement-augmented transiliacal internal fixator (caTIFI): an innovative surgical technique for stabilization of fragility fractures of the pelvis
Introduction
Even though the incidence of pelvic ring fractures is low (0.3 to 8%) [1], an increase over the last two decades can be detected. Demographic data show that especially the incidence of pelvic fractures in the group of over-85-year-old women compared to the overall incidence increased disproportionately high [2]. Looking at data from the German Pelvic Trauma Registry (DGU) 68% of pelvic fractures occurred in patients older than 65 years, with a peak at 85 years, predominantly in females (57%) [3]. These are mainly injuries caused by low energy trauma or even without any trauma (insufficiency fractures). In comparison to the high energy pelvic trauma that leads to transsacral, transiliosacral and transiliac posterior instability, the pelvic ring fracture in the elderly involves mainly sacral fractures with or without involvement of the sacro-iliac-joint leaving the sacro-iliac ligaments intact. There are different existing options to treat these injuries including transiliac bridging procedures (e.g. sacral bar, transiliac internal fixator, ilio-iliac plate), lumbopelvic fixation techniques, or ilio-sacral screw fixation [4].
None of the currently used techniques has been proven to be superior, neither in clinical studies nor in biomechanical analyses. However, especially for the elderly, it is very important to choose an osteosynthesis that allows immediate full weight bearing after operative treatment because this population is often not able to do partial weight bearing and mobilization is mandatory to prevent complications. Another fact is that the elderly patients often present with many comorbidities and therefore, low invasive procedures are preferable.
For the classification of the pelvic ring lesions [5, 6], the system of Tile, adopted by the Association for the Study of Internal Fixation/Orthopaedic Trauma Association (ASIF/OTA) is currently accepted worldwide [7, 8]. In correlation to the classification system for fractures of the extremities developed by the âArbeitsgemeinschaft fĂŒr Osteosynthesefragenâ (AO), Tile distinguishes between three degrees and types of instability, which are easy to discriminate: stable pelvic ring lesions, rotationally unstable lesions and rotationally and vertically unstable pelvic ring lesions. Further discrimination is based on morphologic criteria. The classification system has a high inter-observer reliability [9] and is well related to injury severity and outcome [10, 11].
With regard to the mechanism of injury, it is well accepted that there are important differences between pelvic ring lesions of an elderly injured patient compared to a young adult. Specifically the osteoporotic structure of the bone of an elderly patient leads to the situation that low-energy accidents and even normal physiological loads can lead to a fatigue fracture of the sacrum and the pelvic ring. Even though fragility fractures of the pelvic ring lead to bone disruption, the thick dorsal sacroiliac, sacrotuberal and sacrospinal ligaments remain intact and keep the pelvic ring in its anatomical borders. The fracture fragments can move within these borders and this can generate pain to the patient secondary to micromotion instability. This kind of vertical and rotational instability is not comparable to that of an OTA 61 Type C fracture of young adults [12, 13]. Therefore, a new comprehensive classification system for fatigue fractures of the pelvis was presented 2013 by Rommens and Hofmann [4]. It is based on clinical and radiological criteria and reflects four categories of increasing instability. Lesions within the groups are distinguished by the localization of the instability. Furthermore the classification system gives hints for the extent of surgical therapy and type of fixation, (Table 1).
In 2004, the trans-iliacal internal fixator (TIFI) was described in a prospective study including 31 patients with vertical shear injuries of the pelvis to be a save and minimal invasive surgical technique for stabilization of sacro-iliac joint disruptions and sacral fractures [14]. After longitudinal incision of the fascia the pedicle screws are placed into the posterior superior iliac spine in cranio-caudal direction and the transverse rod can be placed in a minimal invasive manner below the fascia of the spinal muscles. This way the injured hemipelvis is fixed angular stable to the non-injured side. Out of 62 inserted pedicle screws none was positioned incorrectly. Overall, one loosening of a pedicle screw and two superficial wound infection occurred in this study.
To achieve the highest stability by internal fixation with pedicle-screws and rods, a maximum diameter and length of the pedicle-screws is recommended [15]. Especially in osteoporotic bone this is necessary to prevent early failure of the internal fixation. Schildhauer et al. analyzed in a radiographic morphometric study of 40 trauma patients (21 males, 19 females; in the age of 16 to 78 years) the optimal bone corridor to place screws for iliolumbar fusion to treat spinal injuries of the low lumbar spine, sacral or dorsal pelvic ring fractures. He could show that the path from the posterior superior iliac spine to the anterior inferior iliac spine had the largest bony canal lengths, with 141mm in male and 129 mm in female patients. Furthermore, the width of this supraacetabular bone canal allows the placement of implants with a diameter of 8-mm in male and 6- to 7-mm in female patients. Schildhauer proposed that for an optimized iliac screw placement for lumbopelvic fixation appropriate pedicle screws should be placed into this bone stock [16]. The insertion of the screws should be done under intraoperative fluoroscopic control using obturator obliqueâoutlet and standard lateral pelvic views (Fig. 1).
Gaensslen et al. confirmed the results of Schildbauer and described the safe percutaneous placement of Schanz screws in the so called âsupraacetabular bone canalâ of the ilium bone to treat OTA 61 Type B and Type C fractures by a ventral external fixator [17]. Out of 64 supraacetabular external fixator applications (108 Schanz screws) a primary perforation of the Schanz screw into the small pelvis was seen in just two patients (3%).
Cement augmentation is an option to improve the fixation stability of the implant in osteoporotic bone. Cement augmentation of screw fixations in osteoporotic sacral fractures was shown to lead to adequate pain reduction and recurrence of mobility [18, 19, 20].
In this paper, we suggest a minimally invasive stabilization technique for osteoporotic pelvic ring fractures using a cement augmented internal fixator with Schanz screws that facilitates immediate full weight bearing.
Section snippets
Patients and methods
Results
15 patients (14 female) with fragility fractures of the pelvis were diagnosed according to the trauma mechanism and an assured or assumed underlying osteoporosis. Eleven of them suffered a fall from standing height and for three patients recurrent simple falls were recorded as trauma mechanism. One patient suffered a pelvic ring fracture without any trauma.
The average age of the patients with fragility fractures of the pelvis was 79,9 years (SD 9,0 years). The youngest patient was 49years and
Discussion
Improvement of fixation of the posterior elements of the pelvic ring in elderly patients with underlying osteoporosis and related outcomes has received a lot of attention lately [24, 25, 26, 27, 28, 29, 30, 31].
The method described in this paper is a safe and low invasive procedure that provides sufficient stability for full weight bearing in patients with osteoporotic pelvic ring injuries. Four perforations of the iliac cortex without need for revision were recorded. These perforations were
Limitations
Since the number of patients (n = 15) included in this retrospective study is small we were unable to carry out any statistical evaluation.
Conclusion
The main focus of this study was to describe the modified surgical technique of the cement augmented trans-iliacal-internal fixator (caTIFI) with placement of the Schanz screws from the posterior superior iliac spine to the anterior inferior iliac spine into the supraacetabular bone canal rather than placing them in a cranio-caudal direction into the posterior superior iliac spine. Usage of cannulated and perforated Schanz screws gives the opportunity to control the correct position of the
Acknowledgment
We like to thank Nadine Hausmann for assistance for data acquisition.
Conflict of interest
The authors are not compensated and there are no other institutional subsidies, corporate affiliations, or funding sources supporting this work unless clearly documented and disclosed.
References (39)
- et al.
Survival trends and predictors of mortality in severe pelvic trauma: estimates from the German Pelvic Trauma Registry Initiative
Injury
(2011) - et al.
Comprehensive classification of fragility fractures of the pelvic ring: Recommendations for surgical treatment
Injury
(2013) - et al.
Current classification of fractures. Rationale and utility
Radiol Clin North Am
(1997) - et al.
Survival trends and predictors of mortality in severe pelvic trauma: estimates from the German Pelvic Trauma Registry Initiative
Injury
(2011) - et al.
Percutaneous iliosacral screw fixation after osteoporotic posterior ring fractures of the pelvis reduces pain significantly in elderly patients
Injury
(2015) - et al.
Fluoroscopically assisted computer navigation enables accurate percutaneous screw placement for pelvic and acetabular fracture fixation
Injury
(2015) - et al.
Percutaneous iliosacral fixation in external rotational pelvic fractures. A biomechanical analysis
Injury
(2015) - et al.
Factors associated with outcome of spinopelvic dissociation treated with lumbopelvic fixation
Injury
(2014) - et al.
The effect of thread length and location on extraction strengths of iliosacral lag screws
Injury
(1994) - et al.
Stabilization of fatigue fractures of the dorsal pelvis with a trans-sacral bar. Operative technique and outcome
Injury
(2012)
Outcome and complications of posterior transiliac plating for vertically unstable sacral fractures
Injury
Changes in epidemiology and treatment of pelvic ring fractures in Germany: an analysis on data of German Pelvic Multicenter Study Groups I and III (DGU/AO)
Acta Chir Orthop Traumatol Cech
Closed pelvic fractures: characteristics and outcomes in older patients admitted to medical and geriatric wards
Postgrad Med J
How reliable and accurate is the AO/OTA comprehensive classification for adult long-bone fractures?
J Trauma Acute Care Surg
Pelvic ring fractures: should they be fixed?
J Bone Joint Surg Br
Fracture and dislocation compendium. Orthopaedic Trauma Association Committee for Coding and Classification
J Orthop Trauma
Interobserver reliability of the young-burgess and tile classification systems for fractures of the pelvic ring
J Orthop Trauma
Staged reconstruction of pelvic ring disruption: differences in morbidity, mortality, radiologic results, and functional outcomes between B1, B2/B3 and C-type lesions
J Orthop Trauma
MRI and CT of insufficiency fractures of the pelvis and the proximal femur
AJR Am J Roentgenol
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