Reduction and Internal Fixation of Posterior Wall and Column Fractures in Older Patients

Fig. 4.1

AP X-ray of the pelvis. The arrow is pointing at the displaced right posterior wall fragment

../images/395168_1_En_4_Chapter/395168_1_En_4_Fig2_HTML.jpg — Fig. 4.2

3D rendering of a right iliac oblique view. The arrow is pointing to the displaced posterior column fracture

../images/395168_1_En_4_Chapter/395168_1_En_4_Fig3_HTML.jpg — Fig. 4.3

3D rendering of a right obturator oblique view. The arrow is showing the displaced posterior wall fracture

Advanced imaging with CT scans of the pelvis will provide a comprehensive assessment and show non-displaced fracture lines, amount of displacement, articular impaction, and incarcerated fragments that may not be evident on standard radiographs (Figs. 4.4, 4.5, and 4.6).

../images/395168_1_En_4_Chapter/395168_1_En_4_Fig4_HTML.jpg — Fig. 4.4

Axial CT scan of the pelvis showing a right acetabular fracture. The arrow is indicating the displaced posterior column fracture line

../images/395168_1_En_4_Chapter/395168_1_En_4_Fig5_HTML.jpg — Fig. 4.5

Axial CT scan of the pelvis showing a right acetabular fracture. The arrow is indicating the displaced posterior wall fragment

../images/395168_1_En_4_Chapter/395168_1_En_4_Fig6_HTML.jpg — Fig. 4.6

3D rendering showing the right displaced posterior column and posterior wall fragments

Elderly patients rarely present with fractures of the posterior column and/or wall, most commonly sustaining anterior column and/or wall fractures or anterior column posterior hemi transverse fractures [9, 10].

Indications and Contraindications

Patients with concentrically reduced fractures outside of the weight-bearing portion of the acetabulum, joint congruency, secondary congruence, <20% posterior wall involvement, and articular displacement less than 2 mm are fracture characteristics which may be amenable to for nonoperative management [6, 11]. Close clinical and radiographic monitoring is critical in the nonoperative treatment of these injuries to ensure adequate joint stability, overall alignment, and patient function.

The goals of surgical treatment are to provide early mobilization of the patient and to delay or prevent the onset of posttraumatic arthritis by restoring anatomic alignment of the articular surface. Acetabular fracture associated with subluxation or dislocation of the femoral head is generally an indication for surgical treatment. Loss of joint congruence due to fracture pattern, retained fragments, and articular surface displacement >2 mm are additional indications for surgical management of acetabular fractures.

Positioning/Draping/C-Arm

The most commonly employed surgical approach to the posterior wall and column is the Kocher-Langenbeck approach. Patients may be positioned lateral with affected side up or in prone position as per surgeon’s preference. Lateral positioning allows trochanteric osteotomy with or without surgical hip dislocation if necessary for increased exposure and no specialty table is required. Prone positioning affords the benefit of gravitational assistance in reduction, particularly for fractures involving the posterior column and transverse and T-type fractures, and removes the weight of the limb as a deforming force on the fracture.

At our institution, lateral positioning is the preferred methodology. A radiolucent table is utilized with a beanbag and axillary roll to position in the lateral decubitus position with the affected hip up. Standard split drapes are applied over impermeable drapes. Care is taken to ensure that the surgical field includes the posterior superior iliac spine posteromedially, the nipple line superiorly and through the perineum, excluding the anus with the non-sterile impermeable down drape. Hair is clipped as necessary and initial skin cleansing is performed with rubbing alcohol. The ipsilateral leg is prepped into the field and the skin is prepped with an alcohol-based surgical prep. The foot is typically isolated in an impermeable stocking to above the knee. Once the sterile split drapes are placed, the skin and surgical field are covered with an occlusive and adhesive barrier drape. The leg is prepped into the surgical field to allow hip range of motion for both reducing maneuvers and easing tension on the sciatic nerve.

Approach

The Kocher-Langenbeck approach provides complete access to the greater sciatic notch and thus to the posterior column as well as the posterior wall. The incision begins caudally around 5 cm from the posterior superior iliac spine and curve toward the greater trochanter and continues distally midlateral along the femur. Sharp dissection and electrocautery extends this incision down to the iliotibial band and gluteus maximus fascia, which are divided in line with the skin incision. Appropriate position of the division of the iliotibial band in the sagittal plane is confirmed by palpation of the gluteal sling posteriorly. Blunt dissection proximally exploits the natural separation within the gluteus maximus, superiorly.

Dissection is carried down to the short external rotators and the sciatic nerve is identified. The most reliable location of the sciatic nerve is on the posterior aspect of the quadratus femoris. The relationship of the nerve to the piriformis is variable and not as reliable [12]. The piriformis, with its close proximity to the posterior column, may be disrupted by fracture displacement and is therefore not always a reliable landmark. The location of the piriformis tendon is identified, as is the interval between the gemelli and quadratus femoris. Within this interval, there is the triceps tendon of the inferior gemellus, obturator internus and superior gemellus. The tendon is located more on deep surface of this interval, almost adherent to the posterior hip capsule. Take care to isolate the triceps and the piriformis as independent structures to tag and release from their insertion. The authors’ preferred method is to divide the tendons as closely as possible to the insertion point and to repair at closure with absorbable, monofilament suture. Repair through drill holes is not felt to be necessary.

The now-mobilized piriformis can be utilized to guide exposure of the greater sciatic notch. The gluteus minimus is typically excised from the capsule remnant and posterosuperior acetabular surface since it is usually significantly damaged by the injury and surgical approach, may limit visualization of components of the fracture, and is felt to contribute to postoperative heterotopic bone formation when left in place. Following the muscle belly of the obturator internus to the lesser sciatic notch facilitates easy access and exposure to the more caudal elements of the posterior column.

Through this approach, the posterior column down to the ischial tuberosity, posterior wall, and posterior to superior acetabulum are visualized. Fracture reduction and fixation are performed as detailed below.

After fixation, additional debridement of nonviable soft tissue is performed with attention to damaged muscle felt to contribute to postsurgical heterotopic bone formation. Layered closure over a drain consists of repair of the triceps and piriformis tendons to their insertion at the stump left during their release on the initial approach. The gluteal fascia and iliotibial band are then closed with absorbable monofilament suture over the deep drain. This closure may be performed in running or interrupted fashion per surgeon’s preference. The subcutaneous and subdermal layers are closed with absorbable sutures. Depending on skin quality and medical comorbidities, the skin is closed with nonabsorbable monofilament versus staples.

Reduction and Fixation

Once adequate exposure and soft tissue debridement have been completed, cortical and cancellous fracture edges are carefully prepared by dissection of periosteum and removal of fracture hematoma and debris to facilitate assessment of reduction. Distraction of the femoral head can assist with visualization into the acetabulum for removal of osteochondral fragments and other fracture debris and limited direct visualization of articular fracture lines and assessment of osteochondral injury on the femoral side of the joint. A threaded Shanz pin may be inserted from the lateral aspect of the proximal femur up toward the femoral head and a T-handled chuck attached for application of vertical and lateral traction. If in the prone position, the effect of gravity driving the femoral head into the pelvis or displacing the posterior column is lessened.

Once the fracture site has been adequately exposed, prepared, and debrided, the reduction is carried out in a logical progression. Depending upon its presence, location, and extent, marginal impaction may be addressed before or after reduction of the posterior column. Reduction of posterior column displacement may be accomplished with the use of a Shanz pin into the ischial tuberosity to correct rotational malalignment, attachment of a Jungbluth clamp attached via screws on either side of the fracture to achieve multi-planar control, placement of small or large tenaculum bone clamps or pelvic reduction clamps or any combination of the above as necessary. Accurate reduction of marginal impaction fragments is dependent upon a concentric reduction of the femoral head to the intact portion of the acetabulum as this reduced head acts as a template for reduction of the impacted osteochondral fragments. Elevation of these articular fragments is achieved with an osteotome, provisional fixation is obtained with small diameter smooth Kirschner wires, and definitive fixation may be augmented with bone graft or intra-fracture mini-fragment screws if the size of the impaction fragments permits. As stated above, the order of reduction of column, marginal impaction, and wall fragments will vary with fracture configuration.

Once the column is reduced, lag screw fixation is desirable if adequate fracture obliquity is present (Fig. 4.7). This will often allow for removal of provisional clamps facilitating posterior wall reduction and fixation. If not amenable to lag screw fixation, provisional mini-fragment plate fixation can be helpful in allowing clamp removal.