Symphyseal plating for pelvic fracture in a morbidly obese patient: operative challenges and innovation of a novel ‘wire-ramp plate-sliding method’
- Kumar Keshav ,
- Manjunath Nishani ,
- Amarendra Singh and
- Abhishek Singh
- Orthopaedics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
- Correspondence to Dr Kumar Keshav; keshav4700@yahoo.co.in
Abstract
We are describing a case report of a morbidly obese patient (body mass index 41) in his mid-40s with Young and Burgess Anteroposterior Compression type II injury (AO Foundation/Orthopaedic Trauma Association type B1.2) managed by symphyseal plating. Morbid obesity made working at a depth very difficult; hence, we adopted a novel ‘wire-ramp plate-sliding method’. In this method, two strong sturdy K-wires inserted through the medial-most plate holes into the pubis acted as a ramp over which the plate was pushed/slid distally. During this manoeuvre, the K-wires passing through the plate holes were used as a reduction tool. The patient also had a wedge fracture of the distal femoral shaft which was managed by retrograde femoral nailing. At 1-year follow-up, the pelvic continuity is maintained and the fracture has united. The patient is able to do full weight-bearing and is back to his normal life.
Background
Symphyseal plating, one of the commonly performed procedures in pelvi-acetabular domain, is the standard treatment modality in patients having disruption of pubic symphysis.1 However, there are certain challenges depending on the patient profile, pattern of fractures and degree of displacement. Although it is one of the easier surgeries, there are often high failure rates, mostly due to the backout of screws and eventual implant failure which necessitates resurgery.2–4 Morbid obesity makes the otherwise simple surgery quite challenging due to difficult exposure and reduction, requirement of working at a depth and difficulties in screw trajectory due to pendulous abdomen.5–11 We are describing a case report of an AO type B1.2 pelvic fracture in a morbidly obese patient. In order to circumvent the difficulties during the surgery, we innovated a new way of performing symphyseal plating—‘wire-ramp plate-sliding method’.
Case presentation
A morbidly obese patient (body mass index (BMI) 41) in his mid-40s presented at our tertiary care trauma centre after an alleged road traffic accident (direct impact by a four-wheeler). The patient presented to us within an hour of injury in shock. He was managed as per the Advanced Trauma Life Support protocol. Clinical assessment revealed fracture of the pelvis and left femoral shaft. A pelvic binder and below knee skin traction were applied.
Investigations
On getting the relevant X-rays, a Young and Burgess Anteroposterior Compression type II injury (AO Foundation/Orthopaedic Trauma Association type B1.2) was found (figure 1). Along with this, there was a fracture of distal one-third of left femoral shaft (figure 2). The same was confirmed by CT scan, which did not show any significant injury to the posterior ligamentous complex. The patient had a very low haemoglobin level due to profuse blood loss secondary to two major fractures.
X-ray of the pelvis showing symphyseal disruption (AO Foundation/Orthopaedic Trauma Association type B1.2, Young and Burgess Class Anteroposterior Compression 2).
X-ray of the thigh showing wedge fracture of distal one-third femoral shaft.
Treatment
Based on the injury pattern, a symphyseal plating through modified Stoppa approach for pelvic fracture followed by retrograde distal femoral nailing for femoral shaft fracture in the same sitting was planned. The patient required three units of packed red blood cells (two units in the emergency room and an additional one later in the ward) before he could be optimised for the surgical intervention.
A Pfannenstiel incision was given two finger-breaths above the symphysis pubis to expose the pubis bilaterally. However, the pendulous abdomen was the real challenge, since the expected incision line was going to fall on the inferior part of the abdomen which meant vigorous retraction to reach the symphysis (figures 3A,B and 4A–C). After splitting the linea alba, we found the rectus of right side already avulsed. The next step was to clear adhesions between the bladder and the posterior surface of the pubis by entering the space of Retzius. Due to the thick fatty subcutaneous layer, our fingers could barely reach the space as it was around 8–9 cm deep from the skin. We put two malleable retractors in this space to protect the bladder.
Patient profile from front (A) and side (B) showing the morbidly obese patient and his pendulous abdomen.
Intraoperative pictures (A) following prepping and draping, (B) Pfannenstiel incision and (C) splitting of recti.
The next challenge was the reduction of the symphysis and holding it in a manner so that we could apply a plate with screws. Symphyseal disruption in our case was around 3.5 cm. Our attempt to do external compression at the level of trochanters was far from adequate. Putting pointed reduction clamps was difficult at such a depth due to wide separation of symphysis. We could apply it on the superior surface but that would have blocked plate application. There was also the risk of iatrogenic injury to important structures like urinary bladder due to inadequate visualisation. To reduce the fracture, we adopted a novel method—‘wire-ramp plate-sliding method’. This method entails using a thick sturdy K-wire (3 mm in our case) on either side passed through the medial-most plate holes into the pubis while the plate is still far off from the bone. The K-wires then act as a ramp over which the plate is pushed down. While the plate is being pushed down, the K-wires on either side which are passing through the medial-most plate holes come towards each other thereby bringing the hemipelvis closer and reducing the symphyseal disruption (figure 5A,B).
(A,B) Pictorial representation of wire-ramp plate-slide method of fixation.
Keeping the symphysis reduced while inserting screws was a challenge due to the weight of the patient. For ensuring the above, one of the assistants had to keep the plate opposed to the bone with the help of two blunt periosteum elevators. Second, putting a plate on the superior surface of the pubis required drilling and screw insertion at an angle of around 30°–45° in an anteroinferior direction. This trajectory was very difficult due to the protuberant tummy. So, we envisaged using a straight plate on a curved anterior pubic area such that the plate is slightly anteriorly as we go laterally (figure 6). This allowed us to put screws in a posterosuperior direction and get hold in superior pubic ramus in a bicortical fashion (figures 7A–C and 8).
Intraoperative picture following internal fixation by Matta’s plate.
Intraoperative C-arm pictures of the symphysis in anteroposterior (A), inlet (B) and outlet (C) projections.
Immediate postoperative pelvic X-ray showing well-reduced symphyseal disruption having been fixed by Matta’s plate.
For the infra-isthmic femoral shaft fracture, we resorted to retrograde femoral nailing through an infrapatellar approach (figure 9).
Postoperative X-ray of the thigh showing retrograde intramedullary nailing.
Outcome and follow-up
The patient was kept non-weight-bearing for 6 weeks during which physiotherapy exercises like quadriceps strengthening and other exercises were initiated. He was allowed partial weight-bearing with the help of a walker at 6 weeks and full weight-bearing at 3 months. At 1 year of follow-up, X-rays demonstrated reduced symphysis (figure 10) and fully united femoral shaft (figure 11). The patient is able to sit cross-legged and stand and walk unassisted (figure 12). He was unable to squat due to high BMI even before the trauma.
Pelvic X-ray at 1-year follow-up showing well-reduced symphysis and no loosening of the plate.
X-ray of the thigh at 1-year follow-up showing united femoral shaft fracture.
Clinical photographs of the patient at 1-year follow-up.
Discussion
This case demonstrates an innovative method of symphyseal plating in a morbidly obese patient where one encounters challenges at all stages of the surgery—right from exposure to reduction to fixation. We are aware that there could have been various other ways to get the job of symphyseal plating done in this patient. However, our method is one of the novel ones not described anywhere. There are very few papers describing issues related to pelvi-acetabular fractures in morbidly obese patient population, and those describing symphyseal plating in such patients are even rare.5–11
Conservative management of pelvic fractures in these patients is often fraught with higher overall risk of complications. Carson et al from Johns Hopkins University, USA conducted a retrospective observational study on 1331 morbidly obese patients with pelvic and acetabular fractures from National Trauma Data Bank. They found a higher overall complication rate in the morbidly obese (BMI 40) patients compared with the control group. This difference was statistically significant in all except pelvic fracture group managed conservatively.5 However, a study by Porter et al comparing pelvic ring fractures in 102 morbidly obese patients with 186 non-obese patients showed more than twice higher overall complication rate (39% vs 19%, p<0.001) in the former.8
Surgical exposure of pelvis in such patients often requires larger surgical approaches and more surgical expertise.8 Few authors have advocated the use of external fixators in such patients. However, difficulties in palpating bony landmarks and inadequate visualisation under intraoperative fluoroscopy make percutaneous application of ex-fix in this patient population rather challenging. To find a sort of middle ground, Fritz et al described the use of an internal spinal fixator in a morbidly obese elderly woman having a type B1.1 pelvic disruption. They went for minimally invasive technique to avoid the requirement of long incision and consequent wound healing problems in such patients.6 In our case, we could get away with 12.5 cm incision, since we changed the direction of lateral-most screws. Surgical exposure seems inadequate especially while passing lateral-most screws due to the pendulous abdomen coming in the way. Purcell et al in a review paper mentioned about instances where panniculus had been sutured to the chest wall to get it out of the surgical field.11 Baldini-Garcia and Altamirano-Cruz described a complex pelvic fracture where symphyseal plating was done as a part of the procedure. They used Charnley-type retractor for exposure. They had to make two separate stab incisions proximal to the Pfannenstiel incision, through which the screws were placed.7
Reduction of these fractures is difficult. The conventional pointed reduction forceps could not be used in our case due to the depth at which we were working. Baldini-Garcia and Altamirano-Cruz used pelvic reduction forceps by placing two 3.5 mm screws as anchorage.7 However, quite often, these forceps come in the way and do not allow plate fixation easily unless extensive surgical dissection is done. It is here that our novel wire-ramp plate-sliding method helped in reduction in a minimally invasive manner, avoiding the need for extensive exposure. One of the prerequisites of success of our method is that the K-wire used should be strong and sturdy and should be well inside the bone with adequate purchase. This, of course, requires a fair bit of expertise in pelvi-acetabular surgery. Maintaining reduction while the plate is being applied is labour intensive. The pointed reduction forceps often slip while the plate is being applied. In our method, one requires to just keep the plate opposed to the bone and that takes care of reduction.
Fixation modality in such fractures is controversial. Concomitant disruption of posterior ring predisposes to anterior fixation failure. So, there has been a gradual consensus towards ensuring stabilisation of the posterior ring as well.12 In our case, however, the posterior pelvis seemed to be relatively intact and hence we went for anterior fixation only. Because of the concomitant femoral shaft fracture, we had to keep this patient immobilised/on partial weight-bearing for some time. We felt that this immobilisation would help in healing of the posterior injury, which was an incomplete one. Usually, we do put iliosacral screws in such cases. However, because of the bulkiness of the patient (which would have made it challenging and more time-consuming) and other injuries (femoral shaft), which were more important, we decided against putting up an iliosacral screw.
Fixation failure is one of the more common but challenging complications of pelvic fracture fixation. It ranges from 12% to 31% as quoted in literature often requiring reoperation. Our patient has completed 1 year of follow-up and there has not been any obvious screw backout or implant failure. Due to the higher body mass and weight of the body, disruptive forces on open-book type of pelvic fracture are high; hence, primary fixation needs to be strong. Baldini-Garcia and Altamirano-Cruz used two plates in an orthogonal manner to prevent the chances of screw loosening and plate breakage in tile C1.3 fracture.7 Since it was difficult to work at a depth of around 8–9 cm, we could apply only one plate. However, we modified our strategy by passing screws in different directions and getting bicortical purchases to prevent screws from backing out. The trajectory of screws in superior plating is such that the protuberant abdomen is a hindrance. In order to circumvent that, we used a straight plate in such a way that the lateral-most screws were a bit off the pubis anteriorly. This allowed us to go for bicortical purchase in superior pubic ramus in a posterosuperior direction instead of the conventional posteroinferior direction as in case of curved plate. This trajectory was an easy one to put lateral-most screws.
Although we did not encounter any, there are possibilities of a few possible iatrogenic and postoperative complications. The relatively smaller incision is difficult to perform surgery with, especially by the beginners. The insertion of K-wires in each of the hemipelvis needs to be precise. If bladder is not protected properly by the help of malleable retractors, there are chances that the wire may puncture the bladder. Since we are using a single short plate, all we are relying on are the differential screw directions to prevent plate backout. Addition of a separate plate or cable application through the obturator rings may be helpful but would require larger surgical exposure.7 13 Patient compliance for remaining non-weight-bearing for 6 weeks and partial weight-bearing for an additional 6 weeks as one of the causes of successful outcome cannot be overemphasised. It is difficult to generalise the postoperative rehabilitation of morbidly obese patients undergoing surgical interventions for pelvic fractures, which is dictated by the healing status and has to be individualised.8
Our novel surgical technique is one of the possible ways of doing open reduction and internal fixation of symphyseal disruption in morbidly obese patients. However, it needs to be done on several of such patients in future to see its universal applicability.
Learning points
-
Symphyseal plating in morbidly obese patients is quite challenging due to difficult exposure and reduction, requirement of working at a depth and difficulties in screw trajectory due to pendulous abdomen.
-
Our novel surgical technique—‘wire-ramp plate-sliding method’—is one of the possible ways of doing open reduction and internal fixation of symphyseal disruption.
-
In this method, two strong sturdy K-wires inserted through the medial-most plate holes into the pubis act as a ramp over which the plate is pushed/slid distally. During this manoeuvre, the K-wires passing through the plate holes are used as a reduction tool.
-
A straight plate is used instead of the conventional curved one in such a way that the lateral-most screws are a bit off the pubis anteriorly, which allows bicortical purchase in superior pubic ramus when screws are passed in a posterosuperior direction.
Ethics statements
Patient consent for publication
Footnotes
-
Contributors The following authors were responsible for drafting of the text, sourcing and editing of clinical images, investigating results, drawing original diagrams and algorithms, and critical revision for important intellectual content—KK, MN, AmS and AbS. The following authors gave final approval of the manuscript—KK, MN, AmS and AbS.
-
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
-
Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
-
Competing interests None declared.
-
Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.
References
Use of this content is subject to our disclaimer