|SYMPOSIUM ON PELVIC TRAUMA
|Year : 2014 | Volume
| Issue : 1 | Page : 14-18
Surgical approaches of the pelvis
Roop Bhushan Kalia1, Alok Chandra Agrawal2
1 Associate Professor Orthopaedics, All India Institute of Medical Sciences, Raipur CG Chhattisgarh, India
2 Professor and Head of the Department, Orthopaedics, All India Institute of Medical Sciences, Raipur CG Chhattisgarh, India
|Date of Web Publication||6-Jun-2014|
Roop Bhushan Kalia
402 Type V A, All India Institute of Medical Sciences Residential Complex, Kabir Nagar, Raipur - 492 099, Chhattisgarh
Source of Support: None, Conflict of Interest: None
Fractures of the pelvis are difficult injuries to treat surgically. Thorough knowledge of the surgical anatomy is a prerequisite to be able to perform the surgical procedure safely as major neurovascular bundles and viscera are at risk of iatrogenic injury with disastrous consequences which are fortunately rare- but can happen. The approaches ideally need to be learned ideally first on cadavers and then under supervision till thorough familiarity is attained. The learning curve is steep; however it should not dissuade surgeons and once learned can allow for safe internal fixation to be performed in a large number of patients.
Keywords: Anterior approaches, posterior approach, fracture pelvis
|How to cite this article:|
Kalia RB, Agrawal AC. Surgical approaches of the pelvis. J Orthop Traumatol Rehabil 2014;7:14-8
| Introduction|| |
To be able to achieve good outcomes in the surgical treatment of pelvic injuries the first pre-requisite is to completely understand all components of the injury. Once all components of the injury are understood, consideration is directed to the surgical approach. Approaches to the pelvis are challenging as the pelvis is the transition zone between the appendicular skeleton and the axial, houses the urogenital organs and the gastrointestinal tract and provides the route for transit of the neurovascular bundles to the lower limbs. A thorough knowledge of these vital structures is an imperative requirement if iatrogenic injury is to be avoided. Close proximity to the fractures to neurovascular bundles can result in catastrophic complication during fracture exposure, reduction or fixation.
Recently there has been a trend toward minimally invasive surgery for the pelvis due to concerns about the morbidity associated with standard surgical exposures. However, closed reduction of unstable pelvic injuries is extremely difficult and the advantages of minimal invasion are countered by the requirement of expensive high quality imaging which are available only at a handful of institutions.
Correct positioning with radiolucent bolsters, supports and radiolucent table are essential pre-requisites for safe and successful approach of pelvic injuries. Imaging of the pelvis needs to performed before skin preparation and high quality inlet and outlet views are essential for safe placement of implants.
| General principles|| |
Important bony landmarks need to be identified and marked before skin incisions. Careful draping and use of plastic adhesive drapes is recommended for most fractures. To protect neurovascular bundles from injury, muscles need to dissect sub-periosteally. A good surgical approach provides adequate exposure of the fracture with a minimal soft-tissue injury and short operating time.
| Anterior approach to the symphysis pubis and pubic rami|| |
Injuries of the anterior pelvic ring including the symphysis pubis and the pubic rami are best approached by the Pfannenstiel approach. This approach can be extended laterally for reduction and fixation of rami fractures. Fractures of the base of rami need a formal ilio-inguinal approach to avoid vascular injury to the external iliac vessels. Sometimes an inferior median laparotomy is preferable if a concomitant abdominal injury needs exploration.
The urogenital triangle needs to be shaved and a urethral Foley's catheterization needs to be done before draping and skin preparation. The presence of a supra-pubic catheter implies violation the space of Retzius and increases the chances of infection manifold. Management of complete urethral injuries is controversial and passing the catheter as remotely as possible superiorly from the anterior abdominal wall decreases the chances of infection after reconstructive surgery.
The patient is positioned supine on a radiolucent table.
A curved incision is made 2 cm cephalad to the pubic symphysis.
Self-retaining retractors are useful to retract the superficial fascia especially so in obese patients. The external oblique aponeurosis is incised to the external inguinal opening and the spermatic cord and the ilio-inguinal nerve are identified and retracted by a penrose drain. If the symphysis pubis needs fixation a midline vertical incision is made in the lines alba [Figure 1].
|Figure 1: A vertical incision is made in linea alba to allow the lateral retraction of the rectus abdominis|
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The two bellies of the rectus abdominis are separated. This provides adequate exposure for fixation of symphyseal disruptions after careful elevation of the posterior rectus sheath from the anterior body of the pubis. Abdominal packs are inserted in the retro pubic space of Retzius to retract the bladder posteriorly [Figure 2].
|Figure 2: Retracting the two recti opens the retro-pubic space of Retzius and the urinary bladder. Access is gained to the superior surface of the pubic symphysis and the pubis|
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If rami fractures need to be exposed the dissection is continued laterally along the superior surface of the pubis dividing the pectineal fascia and the lacunar ligaments. If further lateral exposure is required it is safer to do a limited ilioinguinal approach using the middle and the lateral windows for exposure.
Corona mortis vessels are an anatomical aberration, which connect the external iliac vessels and the obturator vessels and pass behind the rami close to the bone. This arterial anastomosis has been found in 28.5% of patients in a study.  Accidental injury can lead to profuse hemorrhage. Identification is easy by passing a gloved finger behind the ramus. They can be left alone if only screw fixation is contemplated, however careful ligation is required if a plate fixation is planned.
During closure suction is inserted in the retro pubic space and the rectus sheath is repaired by non-absorbable sutures. Careful repair of the external oblique aponeurosis is required to prevent inguinal hernias.
| ANTEROLATERAL APPROACH TO THE ILIAC WING AND SACROILIAC (SI) JOINT|| |
The anterolateral Olerud approach corresponds to the lateral portion of Letournel's ilio-inguinal approach. The approach exposes both surfaces of the iliac wing and the SI joints and is useful for fixing fractures of the iliac wing, crescent fractures and disruptions of the SI joints. The anterior approach to the SI joint offers safe, reliable access and allows anterior plates to be positioned accurately across the joint. Although the SI joint is one of the most posterior structures in the entire pelvic ring, the anterior approach allows greater exposure and control than does the seemingly more logical posterior approach as anteriorly; the joint is flat and directly available, whereas posteriorly it is overhung by the posterior iliac crest, which limits the access.
Position of the patient
The patient is placed in a supine position on the operating table with a large radiolucent bolster under the buttock. The opposite iliac wing is supported with a support attached to the operating table and the table is tilted 20° toward the opposite side, allowing the mobile contents of the pelvis to fall away from the inner table of the ilium.
A long curved incision  is made over the iliac crest starting at about the level of the iliac tubercle 7-8 cm posterior to the anterior superior iliac spine. The incision is curved anteriorly towards the anterior superior iliac spine and beyond by 5 cm.
The skin incision is deepened through the subcutaneous fat by cutting cautery. The deep fascia overlying the glutei is incised where it attaches to the outer lip of the iliac crest. The periosteum of the entire anterior third of the iliac crest is incised and the muscles off the outer wall of the pelvis to are gently stripped to expose about 1 cm of the outer surface below the crest of the ilium. Iliacus muscle arising from the inner wall of the ilium is detached by blunt dissection to expose the inner table.
Several nutrient arteries entering the inner table bleed after the dissection is completed. This can be controlled either by a large laparotomy sponge packed into the created cavity or by applying bone wax to the bleeding points. After controlling the bleeding the ilio-psoas muscle is retracted medially by a retractor exposing the SI joint. The inner table is accessible to the pelvic brim and below that to digital feel. The key to adequate exposure of the SI joint is adequate anterior dissection. The lateral end of the inguinal ligament and its attachment to the anterior superior iliac spine must be mobilized to visualize the SI joint adequately.
If further medial access is required the aponeurosis of the external oblique muscle is exposed and incised by dividing the aponeurosis of the external oblique muscle in the line of its fibers from the anterior superior iliac spine to the superficial inguinal ring as described by Letournel in the classical Ilio-inguinal approach  [Figure 3]. The lateral cutaneous nerve of the thigh will appear in the lateral edge of the dissection and is hooked by a blunt artery forceps. In most cases, the nerve can be isolated and preserved. This will expose the spermatic cord in the male and the round ligament in the female which are carefully isolated in a Penrose drain. The dissection is continued medially, dividing the anterior part of the rectus sheath to expose the underlying rectus abdominis muscle.
|Figure 3: The skin incision for the ilio-inguinal approach starts from the iliac crest and runs across 2 cm above the inguinal ligament. Any part of the approach can be used for access|
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Divide the conjoint tendon of the Internal oblique and transversus abdominis from the pubis to open the space of Retzius.  The inguinal ligament, which is the in-turned lower margin of the external oblique aponeurosis is incised longitudinally with care and the lacuna musculorum and lacuna vasorum exposed. A rubber drain is passed around the lacuna musculorum consisting of the ilio-psoas and the femoral nerve. By finger dissection the space between the ilio-pectineal fascia and lacuna vasorum is defined and the vessels are carefully retracted by a Langenbach retractor and the ilio-pectineal fascia is divided carefully by a scissors to gain access to the true pelvis [Figure 4].
|Figure 4: The critical deep dissection with delineation of the iliopectineal fascia, which needs to be cut to gain access into the true pelvis|
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After reduction and fixation, a suction drain is inserted into the true pelvis and the wound is closed in layers.
| Posterior approach to the sacrum and si joints|| |
This approach is indicated for SI disruptions, fractures of the sacrum, posterior iliac wing and crescent fractures. It is especially useful posterior ring injuries with significant translational instability. Approach is easy and straight forward, however consideration must be given to soft tissue-injuries like Morelle-Lavalle lesion and other severe intra-cranial, abdominal or thoracic injuries as prone positioning is required. Surgery needs to be delayed until the associated injuries are healed and the soft-tissues are recovered.
Patients need to be positioned in the prone position with bolsters under the chest and pelvis. Care is taken to ensure adequate imaging by taking inlet and outlet views before skin preparation and draping.
A straight skin incision is made beginning 1-2 cm proximal and medial to the posterior superior iliac crest and extending distally to just below the sciatic notch for sacral fractures. For crescent fractures and SI joint disruptions the incision is lateral to the posterior superior iliac spine. Proximally it can be curved along the posterior iliac crest if further exposure is needed. The incision should be avoided on the posterior superior iliac spine especially in thin individuals, as prolonged pressure in the supine position can lead to wound breakdown and difficulties in wound healing.
Incise down into the outer border of the subcutaneous surface of the iliac crest to reveal the layer of ilio-lumbar fascia that covers the gluteus maximus muscle. The origin of the gluteus maximus is detached sub-periosteally from the crest and the muscle is carefully reflected downward and laterally. Branches from the inferior gluteal artery, which emerge from the pelvis, penetrate this muscle from its deep surface. In addition, the inferior gluteal nerve emerges from the notch beneath the piriformis to supply the muscle. Because it is imperative that these two structures be preserved the inferior mobilization of the muscle is limited. As the gluteus maximus muscle is reflected, the gluteus medius muscles will be uncovered along with the piriformis as it emerges through the greater sciatic notch. 
The superior gluteal artery enters the gluteal area superior to the piriformis and needs to be carefully protected during the dissection. The superior gluteal nerve runs close to the superior gluteal artery. A finger is inserted into the greater sciatic notch, which allows the anterior SI joint to be palpated. Release of a portion of the sacro-tuberous ligament may be necessary for adequate medial exposure. Erector spinae and the multifidus muscle may be detached medially from their insertion into the sacrum for sacral alar fractures. The fracture planes can be carefully distracted for debridement as the visualization decreases after reduction. This is important for sacral fractures through the sacral foramina and the sacral canal.
Adequate exposure allows for application of reduction forceps across the fracture planes or the SI joint through the greater sciatic foramen. For vertical shear injuries polyaxial pedicle screw can be inserted into the pedicle of L5 and the posterior ilium for distraction spondylodesis, which effectively neutralizes the shear forces.
| PERCUTANEOUS TECHNIQUE OF ILIO-SACRAL FIXATION|| |
Minimally invasive techniques have an advantage of preserving the soft-tissue envelope; however they are exacting techniques which require excellent fluoroscopic lateral, inlet and outlet views for safe placement of the screws.  Rotationally unstable injuries do not require longitudinal traction and simple draping is often sufficient. Vertically unstable pelvic injuries need peroperative longitudinal traction and it is advantageous to drape the lower extremity free for such an eventuality.
The technique can be performed with the patient in the supine or prone position. The prone position has an advantage that it allows an open approach if problem in reduction is encountered during the percutaneous procedure.
A small lateral incision is given after confirming the position of the sacral promontory on a true lateral image by fluoroscopy at the entry point of the cancellous screw in the ilium. A guide wire is inserted into the soft-tissues by hand and held by a Kocher's clamp and the position verified by fluoroscopy.
| Summary|| |
Adequate surgical exposure is of paramount importance to be able to successfully reduce and fix pelvic fractures. These approaches need to take the general condition of the patient and local soft-tissues condition into consideration for minimizing complications as they can be extensive involving considerable dissection. Adequate experience and knowledge are pre-requisites as various large neurological and vascular bundles are at risk to iatrogenic injury with disastrous consequences to the patient. Accurate positioning, excellent fluoroscopy and careful surgery can minimize complications and result in improved outcomes safely in a large number of patients.
| References|| |
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|2.||Goris RJ, Biert J. A single, midline, extraperitoneal incision for internal fixation of type C unstable pelvic ring fractures. J Am Coll Surg 1995;181:81-2. |
|3.||Karakurt L, Karaca I, Yilmaz E, Burma O, Serin E. Corona mortis: Incidence and location. Arch Orthop Trauma Surg 2002;122:163-4. |
|4.||Letournel E. The treatment of acetabular fractures through the ilioinguinal approach. Clin Orthop Relat Res 1993;292:62-76. |
|5.||Matta JM. Anterior exposure with the ilioinguinal approach. In: Mears DC, Rubash HE, editors. Pelvic and Acetabular Fractures. Thorofare, NJ: Slack; 1986. |
|6.||Moed BR, Karges DE. Techniques for reduction and fixation of pelvic ring disruptions through the posterior approach. Clin Orthop Relat Res 1996;329:102-14. |
|7.||Simonian PT, Routt ML Jr, Harrington RM, Tencer AF. Internal fixation of the unstable anterior pelvic ring: A biomechanical comparison of standard plating techniques and the retrograde medullary superior pubic ramus screw. J Orthop Trauma 1994;8:476-82. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4]