EXTERNAL FIXATION AS A BASIC AND FINAL METHOD FOR TREATMENT OF PELVIC RING INJURIES IN POLYTRAUMA Bondarenko A.V., Kruglykhin I.V., Plotnikov I.A., Talashkevich M.N., Voytenko A.N., Tueva G.A.

Altay State Medical University,

Regional Clinical Hospital of Emergency Medical Aid, Barnaul, Russia

External fixation of the pelvic ring with various transosseous devices is a low-invasive osteosynthesis technique. Despite of wide use of internal fixation techniques, external fixation of the pelvic ring is still actual. The low traumatic impact of the method, possibility of use for opened fractures, rapidness and reliability are essential for patients with polytrauma (PT) [1-11]. At the same time, the difficult installation of nails, difficulties during reposition, especially for non-fresh injuries, problems with fixation of unstable structures of the posterior complex, bulkiness of the constructs, need for external fixation device (EFD) up to full union of a fracture, significant number of complications and low quality of life hinder the wider use of the external fixation methods in pelvic surgery.

There are two types of use of external fixation for pelvic injuries. The first variant is temporary use of EFD as the anti-shock measure for hemodynamic instability at the stage of intensive care. The second one is the use at the profile clinical stage for stabilizing condition with pelvic ring reconstruction. Although the use of EFD for urgent treatment of pelvic instability is supported by all authors, it is considered as an additional fixing method for final reconstruction, and only for some types of fractures [7, 9-12]. The discussion of indications for external or internal fixation of various types of injuries has been continuing [6, 8, 10, 13].

The objective of the study – to find out the peculiarities of the use of external fixation devices as the main and final method of treatment in the reconstruction of pelvic ring injuries in patients with polytrauma.

Materials and methods

For 10 years, from 2008 till 2017, 165 patients with unstable pelvic ring injuries and PT received the treatment in the department of severe associated injury of Barnaul Regional Clinical Hospital of Emergency Medical Care. The main and final method of treatment was external osteosynthesis. The study did not include the patients with combination of external and internal osteosynthesis (EFD or iliosacral screws, EFD and pelvic plates) and the patients with unstable hemodynamics who received the temporary external fixation of the pelvic ring. Despite that we adhere to integration of different osteosynthesis techniques for treatment of pelvic injuries, it was decided to analyze the results of EFD only in “clear” view. The study was conducted according to World Medical Association Declaration of Helsinki – Ethical Principles for Medical Research Involving Human Subjects, 2013, and the Rules of clinical practice in the Russian Federation (the Order by the Russian Health Ministry, June 19, 2006, No.266), with the written consent for participation in the study and approval from the local ethical committee.

There were 92 (55.8 %) men and 73 (44.2 %) women. The age varied from 14 to 72, the median age (Me) – 33, the interquartile range – 24-49. There were 67 (40.6 %) employed persons, 53 (32.2 %) unemployed persons of working age, 22 (13.3 %) students, 23 (13.9 %) retired. The causes of PT were road traffic accidents in 109 (66.1 %) patients, falling from height in 45 (27.3 %), crushing injury in the pelvic region in 11 (6.6 %) patients. 52 (31.5 %) patients suffered from industrial injuries. Associated injury was diagnosed in 131 (79.4 %) patients, multiple injury – in 31 (18.8 %), combined injury – in 3 (1.8 %). According to ISS [14], severe PT without life threat (17-25 points) was noted in 80 (48.5 %) patients, severe PT with life threat (25-40) – in 58 (35.1 %), critical (≥ 41) – in 27 (16.4 %). Traumatic brain injuries (TBI) of various severity were diagnosed in 89 (53.9 %) persons, locomotor system injuries in other regions – in 98 (59.3 %).

Closed pelvic injuries were noted in 144 (87.3 %) patients, opened injuries – in 21 (12.7 %). AO/SIF classification was used for estimation of pelvic injuries [15]. Injury types (stable or unstable), location (unilateral or bilateral) and characteristics of injured structures were estimated. The last one means the dominating injury to the ligamentous apparatus of pelvic junctions or bone fractures. This moment is not reviewed appropriately in the studies. A fracture heals by means of callus formation which resists the external factors, and becomes stronger over time. The ligamentous apparatus of the junctions restores with formation of connective tissue scar, which has some mobility. Because of this, displacement of pelvic ring fragments (up to 2 cm) does not interrupt the union and almost has no influence on its static and dynamic functions. At the same time, the same displacement in the junctions results in disordered congruence, instability and degenerative arthrosis.

The table 1 shows the distribution of the patients according to severity in dependence on a type of injury to the posterior pelvic ring according to AO-ASIF and distribution into the subgroups. The patients had 219 injuries to the structures of the posterior semi-ring of the pelvis. 109 (66.1 %) patients had the partially stable injuries to the pelvic ring (type B – horizontal and rotation instability) because of injuries from anterioposterior (AP) and lateral (L) compression. 56 (33.9 %) patients had the unstable injuries (type C – vertical instability) as result of injuries after displacement or combined impactions. 111 (67.3 %) patients had the unilateral injuries to the posterior complex, 54 (32.7 %) – bilateral. Among 219 injuries to the posterior pelvic semi-ring, the bone fractures (sacrum and iliac bone) were found in 129 cases, ruptures of the ligamentous apparatus of the iliosacral junctions (ISJ) – in 90. The ratio of injuries to the posterior part of the pelvis in view of injuries of the ligamentous injuries to ISJ to fractures of bones was 0.69.

Table 1

Injuries to posterior pelvic ring in the patients (n = 165)

Type of pelvic ring injury (61) according to AO-ASIF	Abs.	%
В1.1 – incomplete unilateral injury, external rotation, rupture of anterior cruciate ligament	19	11.5
В1.2 – incomplete unilateral injury, external rotation, sacrum fracture	37	22.4
В2.1 – incomplete unilateral injury, internal rotation, sacrum fracture	17	10.3
В2.2 – incomplete unilateral injury, internal rotation, rupture of anterior cruciate ligament	6	3.6
В2.3 – incomplete unilateral injury, internal rotation, fracture of posterior part of iliac bone	10	6.1
В3.1 – incomplete bilateral injury, “opened book”, rupture of anterior cruciate ligament	4	2.4
В3.2 – incomplete bilateral injury, opened book as a main injury, contralateral lateral compression of sacrum	9	5.5
В3.3 –incomplete bilateral injury, lateral compression of both halves of pelvis	7	4.2
С1.1 – complete unilateral injury, through iliac bone	8	4.8
С1.2 – complete unilateral injury, rupture of anterior cruciate ligament	5	3
С1.3 – complete unilateral injury, through sacrum	9	5.5
С2.1 – complete unilateral injury through iliac bone, incomplete contralateral injury	4	2.4
С2.2 – complete unilateral injury through anterior cruciate ligament, incomplete contralateral injury	10	6.1
С2.3 – complete unilateral injury through sacrum, incomplete contralateral injury	15	9.2
С3.1 – complete bilateral injury, extrasacral rupture of anterior cruciate ligament on both sides	1	0.6
С3.2 – complete bilateral injury, unilateral fracture of sacrum, rupture of anterior cruciate ligament on other side	2	1.2
С3.3 – - complete bilateral injury, sacrum fracture on both sides	2	1.2
Total	165	100

The table 2 shows the characteristics of the injuries to the anterior pelvic semi-ring. As seen, the injuries to the anterior pelvic semi-ring are more often presented by fractures of branches of the pubic and ischial bones, rarer – by ruptures of pubic symphysis. The differences in the incidence were statistically significant (p < 0.05). There were 2 (1.8 %) patients with ruptures of pubic symphysis among 107 patients with fractures of the anterior pelvic semi-ring, and 10 (21.7 %) ruptures of pubic symphysis among 46 patients with fractures of pubic and ischial bones. The differences were statistically significant (p < 0.05). Therefore, ruptures of pubic symphysis were more often in the patients with the most severe pelvic injuries.

Table 2

Injuries to anterior pelvic ring in the patients (n = 165)

Injury type	Fractures of branches of pubic and ischial bones		Ruptures of pubic symphysis*		Total
Injury type	Abs.	%	Abs.	%
Partially stable injury (type B) (n = 109)	107	64.8	2	1.2	109
Unstable injury (type C) (n = 56)	46	27.9	10	6.1	56
TOTAL	153	92.7	12	7.3	165

At admission, external fixation of the pelvic ring was urgently conducted for 11 patients. The indication was opened injuries to the pelvis (mainly, the anterior semi-ring) and evident instability of the posterior one. In other patients, the terms of realization of operations varied from several hours to 60 days after injury (Me – 5 days, interquartile range – 3-10 days). The main number of operations with EFD was performed on in the first week of hospital treatment immediately after stabilization of patients’ condition.

The aim of pelvic reconstruction was creation of the posterior pelvic stability, restoration of congruence in iliosacral joints and recovery of pelvic symmetry. The indications for reconstruction were diastasis in pubic symphysis more than 2.5 cm or vertical displacement more than 1 cm, any displacement of more than 1 cm in the posterior part, internal rotation of hemipelvis more than 15 degrees according to the axial view of CT image.

Four main variants of configuration of external fixations devices were used:

1. On the basis of four nail-screws, diameter of 4.5-6.5 m, which are placed into the iliac wings with anterior C-frame (Fig. 1). The AO-ASIF specialists call it “the upper way” [13].

Figure 1
To the left – a pelvic injury 61В1.1с4 fixed with EFD

(a, b), X-ray images before and after surgery,

to the right (c) – the appearance of the patient.

2. A similar four-rod configuration with the anterior C-frame which is different from the previous one in conduction of one rod on each side into the anterioinferior pelvic spine instead of the crest (Fig. 2). The AO/ASIF specialists call such placement of EFD rods as “the lower way” [13]. Since a screw-nail goes through the supraacetabular region (more dense part of the iliac bone), the lower way has more rigidity of fixation as compared to the upper way.

Figure 2

To the left – a pelvic injury 61С1.2а2с3 fixed with EFD

(a, b), X-ray images before and after surgery,

to the right (c) – the appearance of the patient.

3. The original configuration of EFD, which has been developed in our department (the patent No.2277876 “A method of treatment of fractures and lacerations of the pelvic ring with vertical and rotational displacement [16]), consisting in pelvic introduction of three nail-screws on each side, which made the supporting points in mutually transverse planes. The anterior semi-ring was fixed with neutral positioning of the nail-screws in the anterior four-angle frame. The posterior semi-ring was fixed after making the additional angle compression with nail-screws in the supraacetabular regions. The free ends of the rods (over the skin) formed the equilateral triangle. After fixation in Ilizarov’s constructs, the indicated condition allowed removing the horizontal and rotation displacement of the pelvic bones (Fig. 3). This configuration was “the lower way”, with higher rigidity of fixation and a possibility for better manipulation with fragments during reposition.

Figure 3

Unstable pelvic injury С2.3а1b1с1 fixed with original EFD,
to the left (a) – the appearance, to the right (b) – X-ray image.

4. The original configuration of EFD with stabilization of one femur which has been developed in our department (the patent No.2477089 “The way for treatment of fractures of proximal femur” [17]). This configuration is used for treatment of pelvic ring injuries relating to acetabular and femoral fractures. Two or three nail-screws were introduced into the iliac wings and supraacetabular region on both sides. Then the external frame was mounted. The nail-screw was introduced into acetabular region. It was strengthened in the semi-ring or the arc of Ilizarov device for traction along the axis of the femoral neck in central displacements. Two crossing pins were introduced into the supracondylar region. They were strengthened and tightened in the ring for traction along the axis of the extremity. All elements of the construction were connected with screws (Fig. 4). Depending on conditions, the necessary number of the supports was used for femur fractures.

Figure 4

Pelvic injury 61В3.3а1b3с3, the hip – 32В3.1,

to the left (a, b) – X-ray images before and after surgery,

to the right (c) – the appearance of the patient.

The table 3 shows the use of various types of EFD configuration depending on injury severity. As one can see, the first variant (the upper way) was used only for 23 (13.9 %) patients with partially stable injuries to the pelvic ring. More rigid EFD systems were used more often: the second variant (the lower way) – 53 (32.1 %) patients, the third variant – 82 (49.7 %). Pelvic EFD relating to femoral EFD (the fourth variant) was used rarely – 7 cases (4.2 %). There were not any statistically significant differences in use of various EFD configurations in various types of injuries to the pelvic ring (p > 0.05).

Table 3

Variants of EFD assemblies in different types of injuries

Type of pelvic ring injury	Variants of EFD assembly				TOTAL
Type of pelvic ring injury	variant 1	variant 2	variant 3	variant 4	TOTAL
Type B – partially stable (n = 109)	23	37	44	5	109
Type C – unstable (n = 56)	-	16	38	2	56
TOTAL	23	53	82	7	165

One should note that all variants of EFD were used only with the anterior frames. It was associated with the fact that all patients with PT had several injuries to various organs and systems, and need for supine position during most part of the profile clinical phase. The closed ring system of EFD or the posterior frame could not be used due to possible development of hypodynamic complications. Osteosynthesis was conducted with use of the construction of the Pilot factory of Ilizarov Center (Kurgan, Russia).

The hospital mortality, characteristics of complications and treatment results were considered during estimation of the results. The statistical analysis of the data was initiated with construction of the frequency polygon. The statistical significance of the results was estimated with χ2 test with Yates' correction and Bonferroni’s technique with multiple comparisons. The critical level of significance was less than 0.05 when testing the null hypotheses [18].

RESULTS AND DISCUSSION

3 (1.8 %) patients died, including 2 patients with sepsis and 1 with pulmonary embolism. 2 patients had the unstable (type C) unilateral injuries to the pelvic ring, 1 patient – partially stable (type B) bilateral injury. The factors promoting the complications were massive traumatic detachment of soft tissues of in the pelvic region (Morel-Lavalle syndrome), and hypodynamia. The cause of hypodynamia was severe TBI with coma state in 2 cases, and high body mass in one case. 2 patients received EFD with 4th variant with fixation of pelvic and femoral fractures, 1 patient (the upper way) – 1st variant without rigid fixation of fragments. It caused the loosening of the nail-screws, contamination of tissues, and distribution of the process deathwards.

The table 4 shows the characteristics and the rate of the somatic complications. The bronchopulmonary complications were more often in the patients with severe PT (26 points and more). Among them, 4 patients had the pelvic ring injuries of type B, 10 – type C, 9 – unilateral injuries, 5 – bilateral injuries, 6 – a dominating injury of the bone component of the pelvic ring, 8 – a dominating injury of the ligamental component. Pneumonia was caused by multiple rib fractures with lung contusion in 7 patients, severe TBI with long term ALV – in 9. Totally, injuries in other locations caused more bronchopulmonary complications as compared to pelvic injuries.

Table 4

Features and frequency of somatic complications in the patients (n = 165)

Types of complications	Abs. number	%
Pneumonia, pleuritis	14	38.9
Deep venous thrombosis in lower extremities	9	25.0
Bed sores	8	22.3
Sepsis	3	8.4
Adhesive obstruction	1	2.7
PE	1	2.7
TOTAL	36	100

Clinically significant deep venous thrombosis (DVT) of the lower extremities and the pelvis were in 9 patients with severe PT (26 points and more). 3 patients had some pelvic injuries of type B, 6 patients – type C. Unilateral injuries were in 2 patients, bilateral – in 7. A dominating injury to the bone component of the pelvic ring was in 4 patients, to the ligamentous one – in 5. Fractures of the lower extremities were only in 3 patients. No clinically significant thrombosis was found after ultrasonic examination in the first day. It appeared on the days 5-7 after injury and was mostly determined by acute massive blood loss with subsequent development of thrombophilia, but not by vascular injury.

Bedsores in the lumbosacral region were in 8 patients. Among them, 2 patients had polytrauma with severity of 17-25, 6 patients – 26 and more. 2 patients had some injuries to the pelvic ring of type B, 6 type C. Bilateral and unilateral injuries to the posterior complex were characterized by similar frequency (4/4). A dominating injury to the bone component of the pelvic ring was in 3 patients, to the ligamentous component – in 5. The bedsores were caused by hypodynamia in the patients with severe TBI.

Sepsis developed in 3 patients. In caused death in 2 patients (described above). Sepsis was treated successfully in one patient with PT severity of 41, a bilateral injury to the pelvis of type C (fixed with EFD according to the second variant), severe TBI, bilateral multiple fractures of the ribs and the sternum, and lung contusion. The patient recovered.

Adhesive obstruction developed in one patient with PT severity of 59, an opened pelvic fracture (bilateral unstable injury to the pelvic ring), with dominating injury to the ligamentous component and colon injury. After admission, primary surgical management of the opened fracture and laparotomy with colostomy were conducted. Adhesive obstruction was corrected, but required for two procedures of recurrent laparotomy on the days 7 and 11.

Therefore, somatic complications were noted in the patients with severe PT (> 26), severe TBI, injuries to the internal organs to the chest and the abdomen, unstable bilateral injuries to the pelvic ring with a dominating injury to the ligamentous component (p > 0.05).

Local complications were identified in 88 (53.3 %) patients. Their characteristics and the rate are presented in the table 5. Infectious complications were most common. Inflammation of soft tissues around the nail-screws was identified in 29 patients. Among them, 11 patients had pelvic ring injuries of the type B, 18 – type C, 9 – unilateral injuries, 20 – bilateral injuries, 19 – instability of the posterior complex with the ligamentous apparatus laceration, 10 – fractures. 24 patients had PT severity more than 26 points. 2 patients had inflammation of paravesical cellular tissue with formation of phlegmonas. Inflammation of soft tissue hematoma in the pelvic region was found in 16 patients, including 5 patients with opened fractures of the pelvis. Soft tissue bedsores in the region of the nail-screws were found in 12 cases.

Table 5

Features and rate of local complications in the patients (n = 165)

Complications	Number	%
Inflammation of soft tissues around EFD rods	29	32.9
Hematoma purulence in pelvic region	16	18.2
Paravesical cellular tissue inflammation	2	2.3
Neurological disorders	11	12.5
Soft tissue bed sores in region of rods-screws	12	13.6
Instability of transosseous elements	11	12.5
Secondary displacements	5	5.7
Fractures of rods	2	2.3
TOTAL	88	100

As one can see, the local infectious complications were more often identified in injuries of type C, and in bilateral injuries to the posterior complex with a dominating injury to the ligamentous apparatus (p < 0.05).

Neurological disorders were found in 3 patients with transsacral instability as a traumatic damage of the roots of the lumbosacral plexus, 2 – as clinical disorders of fibular nerves, - 1 – as tibial nerve disorder. One year after the conservative treatment, the lost functions recovered in all patients.

The instability of the nail-screws was found in 11 patients (3 – bilateral partial injury, 5 – full bilateral, 3 – full unilateral). The cause was incorrect introduction of the rods into the iliac wing with its low thickness, excessive body mass or hyperactivity of a patient. Usually, removal of the rods was realized on the side of a laceration of the sacroiliac junction on the second week after osteosynthesis. In one case, it resulted in recurrence of pelvic ring deformation.

The fractures of the nail-screws were in two patients. Both patients had the full bilateral injuries to the posterior semi-ring and transsympheseal instability. The broken nail-screws were replaced.

Secondary displacements or recurrence of deformation were noted in 5 patients. In one case, a displacement in the posterior complex appeared during removal of the rods in a partial unilateral injury to the posterior semi-ring with transsympheseal instability two weeks after osteosynthesis. In 4 cases, the vertical displacement appeared in bilateral injuries (3 complete and 1 partial ruptures of the posterior pelvic semi-ring) within 1.5-3 months. Moreover, the secondary displacement was caused by insufficient fixation of the posterior parts of the pelvis in full bilateral injuries to the posterior complex in the patients with obesity.

Therefore, the local and somatic injuries more often developed (60.8 %) in the patients with injury severity of 26 and higher, with unstable bilateral injuries to the posterior complex and a dominating injury to the ligamentous apparatus (64.7 %). The differences were statistically significant (p < 0.05).

The long term results of the treatment were studied within 3-6 years after trauma. 84 patients (50.9 %) were examined. The outcomes (Majid scale) [19] were: excellent – 20 (23.8 %), good – 29 (34.5 %), satisfactory – 28 (33.3 %), bad – 7 (8.4 %). The positive results prevailed.

The bad results were determined by intense pain syndrome, the extremity shortening, pelvic deformation, need for additional support during walking and lost working capability. All patients with unsatisfactory results had the significant vertical and dorsal displacement in the posterior semi-ring (more than 2 cm): 6 – because of dislocation in the sacroiliac joint, 1 – as result of unhealed sacral fracture. No cases were associated with development of chronic posttraumatic osteomyelitis of the pelvis.

CONCLUSION

1. The highest number of complications, longer time of fixation, longer hospital stay, general duration of treatment and the worst long term results were found in the patients with unstable bilateral injuries to the pelvic ring with a dominating injury to the ligamentous apparatus.

2. More rigid stable fixation of the fragments is achieved with EFD with use of “the lower way) or the original three-rod configuration. These external fixation devices can be used as a final method at the stage of intensive care.

3. It is not allowed to use pelvic EFD with femur fixation for patients with PT at the intensive care stage since they limit the mobility and cause hypodynamic complications.

4. EFD is not indicated for massive traumatic detachments of soft tissues in the pelvic region (Morel-Lavalle syndrome) because of higher possibility of tissue infection near the transosseous elements.

5. Use of EFD as the main and final technique of fixation of the pelvic ring should be careful in patients with excessive body mass due to higher possibility of infectious complications.

Information about financing and conflict of interests

The study was conducted without sponsorship. The authors declare the absence of clear or potential conflicts of interests relating to publication of the present article.