Fracture Characteristics

Both-column fractures are associated with an incidence of approximately 20% and therefore belong to the most common acetabular fracture types.¹

As there is complete detachment of the articular surface from the remaining posterior pelvic ring,² a floating acetabulum³ is present.

Primarily, there are two main fracture lines separating the anterior from the posterior column connecting at the supraacetabular region. The acetabular roof is normally completely attached to the anterior column (▶ Fig. 17.1). These primary fracture lines are often extended by secondary fracture lines, resulting in additional injuries and more complex column fragments.

The fracture line of the posterior column typically starts near the most proximal part of the greater sciatic notch and fractures the joint surface at a variable point at the posterior-cranial area reaching the acetabular fossa. The inferior pubic ramus is fractured at variable sites. An additional posterior wall fracture is possible. Posterior fractures can extend to even the linea terminalis.

The fracture of the anterior column typically starts variable at the iliac crest. Sometimes, a multifragmentary fracture with a triangular fragment near the sacroiliac (SI) joint can be present. Uncommonly, the anterior fracture starts more distal, between the anterior superior and anterior inferior iliac spine. If this latter fracture line has a more horizontal connection to the main posterior column fragment, transition fractures to T-type fractures can be present. In rare cases, the SI joint may be involved.

Typically, the anterior main fracture line meets the primary posterior fracture line superior to the acetabulum.

Radiographically, the pathognomonic sign of a both-column fracture is the spur sign (▶ Fig. 17.2).^2,​4 This is caused because the intact posterior iliac segment, connected to the SI joint, remains in its anatomical position, whereas the fractured free acetabular fragments are displaced medially. In the obturator oblique view (OOV), this results in a characteristic lateral bony spike.^2,​4

The most common both-column fracture starts cranially at the iliac crest as a multifragmentary fracture of the anterior column, whereas the posterior fragment corresponds to an isolated posterior column fragment. A multifragmentary posterior fracture or an anterior column fracture extending into the SI joint is unusual (▶ Fig. 17.3). A central femoral head dislocation is possible and was observed in up to 42%.⁵ In approximately one-fifth of the cases described in the literature an acetabular roof comminution was observed. Additional pelvic ring injuries are reported in up to 45%.⁵

17.2 Radiological–Anatomical Criteria

• 
  

  Pelvic anteroposterior (AP) view (▶ Fig. 17.4a). The characteristic lines of the anterior and posterior column (e.g., the iliopectineal and ilioischial line) and the anterior and posterior wall line are disrupted. The femoral head is usually dislocated centrally together with the posterior column fragment. The iliopectineal line is disrupted far cranially. The acetabular roof is completely displaced and internally rotated. The iliac crest is fractured at a variable point. The bony ring of the obturator foramen is fractured at the inferior pubic ramus. Occasionally, a spur sign becomes visible, representing the both-column fracture (see OOV). Frequently, additional lesions of the pelvic ring (symphyseal disruption rupture, SI joint injuries, fractures of the contralateral pubic rami) are present.

  
  
• 
  

  Iliac oblique view (IOV) (▶ Fig. 17.4b). Fracture lines at the iliac fossa or at the iliac crest are best seen. The ilioischial line is disrupted near the greater sciatic notch indicating the fracture of the posterior column. A fracture line through the quadrilateral surface separates both columns. At the anterior column, a disruption of the anterior acetabular horn may be present.

  
  
• 
  

  Obturator oblique view (OOV) (▶ Fig. 17.4c). The exact fracture course along the linea terminalis becomes clear as well as the disruption of the obturator foramen. The pathognomonic spur sign is clearly visible.

  
  
• 
  

  Computed tomography (▶ Fig. 17.2d, ▶ Fig. 17.2e). Step-by-step analysis of the axial views detects the complete separation of the joint surfaces from the axial skeleton. The exact extent and position of the fragments becomes clear. Three-dimensional (3D) views improve the overall understanding of the both-column fracture significantly.

  
  
• 
  

  Transition forms to other fracture types. In low anterior column fractures (between the anterior superior and anterior inferior iliac spine), transitional forms to T-type fractures are possible, if small parts of the articular surface remain uninjured. If the CT analysis presents an articular part connected to the axial skeleton, transition types to associated anterior column plus posterior hemitransverse fracture may be present.

  
  
  
  

  

  
  

  Fig. 17.4 (a) Both-column fracture. The pelvic AP view identifies the iliac fracture lines and the extent of the fracture at the acetabulum with disruption of the iliopectineal and ilioischial line. (b) The IOV demonstrates the posterior column fracture and the extent of the iliac fossa involvement. (c) The OOV visualizes the spur sign (white dotted line).

17.3 Pathobiomechanics

Both-column fractures typically result from forces along the greater trochanter and forced medialization of the femoral head against the acetabulum. This mechanism is comparable to the mechanism resulting in pure transverse fractures. Letournel observed both-column fractures exclusively after this mechanism.² Dakin et al described these forces with a frequency of 44%.⁶

A typical fracture morphology results from the following: the lateral directed pressure against the acetabulum leads to a fracture just below the level of the linea terminalis; this fracture line typically extends into the iliac fossa; it reaches the iliac crest and leads to an external rotation around an axis within the superior pubic ramus; and this results in a cranialization of the anterior column fragment (▶ Fig. 17.2e).

The posterior column may be displaced variably or only slightly displaced. Usually a medialization of the posterior column is observed together with an internal rotation of the whole column. The posterior column is often without any contact to the femoral head.³

17.4 Hip Joint Stability

Due to the fracture morphology resulting in a floating acetabulum, both-column fractures are considered potentially unstable.

However, minor displaced fractures may be associated with a sufficient intrinsic stability. Due to ligamentotaxis, the periacetabular fragments may be congruently positioned around the femoral head, even if the femoral head is displaced medially.^2,​7 Regarding classical fracture healing, a certain stability is assumed allowing partial weight bearing.

Pierannunzii et al suggested that secondary congruence often results in some coxa profunda with possible subsequent multidirectional impingement potentially leading to an impaired functional outcome.³

17.5 Treatment Indications

The majority of the both-column fractures are treated operatively.^8,​9 An anatomical joint reconstruction significantly increases the probability of a good to excellent long-term result.⁸

17.5.1 Operative Treatment

Operative treatment is indicated in^2,​5,​10:

• 
  

  Articular displacement > 2 mm

  
  
• 
  

  Unstable hip joint

  
  
• 
  

  Femoral subluxation/dislocation (incongruence)

  
  
• 
  

  Relevant central femoral head dislocation with the risk of femoroacetabular impingement

  
  
• 
  

  Additional displaced posterior column or wall fracture

  
  
• 
  

  Incarcerated soft tissues

  
  
• 
  

  Intraarticular fragments

  
  
• 
  

  Extended superior dome involvement

  
  
• 
  

  Presence of marginal impaction

  
  
• 
  

  Neurovascular injuries

17.5.2 Conservative Treatment

In a special subgroup of both-column fractures, conservative treatment aiming for secondary joint congruence is considered an option.

The concept of secondary congruence was defined by Letournel and describes an extraanatomic arrangement of the fracture fragments around the femoral head.² Thus, healing with development of a secondary acetabular joint equivalent is possible. Conservative treatment provides a possible alternative in patients not suitable for operative treatment, such as those patients with general contraindications such as higher grade cardiovascular pathologies, local soft tissue problems (Morel-Lavallée lesions), or polytraumatized patients in the stabilization phase.⁷

17.6 Techniques of Osteosynthesis

17.6.1 Biomechanics of Osteosynthesis

Levine et al analyzed the influence of secondary joint congruence in simulated both-column fracture.¹¹ Congruence was performed by supraacetabular and posterior plate osteosynthesis.

There was a significant increase in the resulting forces at the superior dome area and a corresponding decrease at the anterior acetabulum, but no significant changes were observed at the posterior joint area.¹¹

17.6.2 Approach

Operative stabilization of both-column fractures is possible via various approaches:

• 
  

  Anterior approaches

  
  
  
  
  • 
    

    Ilioinguinal approach^{2,​5,​8,​9,​10,​12,​13}

    
    
  • 
    

    Intrapelvic approach^{14,​15,​16,​17,​18,​19,​20}

  
  
• 
  

  Extended iliofemoral approach according to Letournel^{2,​13,​21,​22}

  
  
• 
  

  Simultaneous anterior and posterior approaches^13,​23

Operative treatment of both-column fractures was predominantly performed using the ilioinguinal approach for long time. In large series, the ilioinguinal approach was used in 50%, an extended approach in 25%, and the Kocher-Langenbeck approach in 17%.^2,​8,​24 With the introduction of the intrapelvic approach, this approach’s favorability has increased.^{14,​15,​16,​17,​18,​19,​20}

The choice of approach depends on fracture morphology. Because, in the majority of cases, a multifragmentary fracture of the anterior column with a simple large posterior column fragment is present, anterior approaches are recommended.^5,​10

The presence of a displaced posterior wall fracture or a multifragmentary fracture of the posterior column with and without posterior marginal impactions does not allow anatomical posterior reduction using an anterior approach. Thus, a primary of secondary posterior approach is recommended.

In high posterior column fractures, extending to the superior border of the greater sciatic notch, a relative indication is seen using a posterior approach. Here, the intrapelvic approach is an alternative.

In both-column fracture SI joint injury—a transiliac fracture dislocation—an extended approach can be considered. These fractures can additionally be sufficiently treated using an ilioinguinal approach or an intrapelvic approach with opening of the first window.

Some authors described the combined use of an anterior and posterior approach within one surgical step or sequentially. Harris et al simultaneously used an ilioinguinal and Kocher-Langenbeck approach.²³ The mean operating time was 280 minutes with a mean blood loss of 1735 mL. In general, the use of combined approaches is rarely performed. Matta used this technique in only 2%, Letournel in 3%, and Mayo in 4%.^2,​8,​25

Comparative data on the choice of surgical approaches for both-column fractures are reported by some authors.

• 
  

  Letournel’s analysis of 158 both-column fractures reported the use of the Kocher-Langenbeck approach in 19.6%, the ilioinguinal approach was used in 50.6%, the extended iliofemoral approach in 18.4%, and a combined approach in 9.4%.²

  
  
• 
  

  The First German Multicenter Pelvis Study Group evaluated 55 surgically treated patients with both-column fractures. The Kocher-Langenbeck approach was used in 20 patients, the ilioinguinal approach in 17 patients, and a Smith-Petersen approach in two patients. Eleven patients were treated using an extended approach (5 extended iliofemoral approach, 6 Maryland approach), five patients using a simultaneous approach combination, and two patients were treated with a sequential approach combination.²⁴

  
  
• 
  

  Tannast et al reported on Matta’s data of 234 both-column fractures: 1% of patients were treated using the Kocher-Langenbeck approach, 65% using the ilioinguinal approach, 32% using the extended iliofemoral approach, and 2% using a combined AP approach.¹³

Whenever possible, an isolated approach should be used.^{26,​27,​28} Because anterior approaches are the most frequently used approaches, the reduction and stabilization concept is described for the ilioinguinal and the intrapelvic approaches.

17.6.3 Reduction and Stabilization Techniques

The reduction technique is adapted to the selected approach. A simple isolated approach is favored. Correspondingly, the following reduction techniques using the ilioinguinal approach and their modifications for the intrapelvic approach are described.

Ilioinguinal Access

Various instruments are available for reduction. The following reduction aids are most frequently used (▶ Fig. 17.5):

• 
  

  Long-pointed reduction forceps (Weller forceps)

  
  
• 
  

  Farabeuf forceps

  
  
• 
  

  Matta clamps

  
  
• 
  

  Asymmetrical reduction forceps

  
  
• 
  

  Ball spike pusher

  
  
• 
  

  Colinear reduction forceps

  
  
• 
  

  5-mm Schanz screw with T-handle

  
  
  
  

  

  
  

  Fig. 17.5 Typical reduction aids used in the treatment of both-column fractures.

In addition, laminar spreaders and various raspatories or periosteal elevators and small plates are used for optimizing reduction.

The reconstruction techniques of both-column fractures using the ilioinguinal approach is already described in detail.^{2,​5,​10,​29}

The reduction and stabilization concept comprises of two essential steps after dissection of the three windows of this approach:

• 
  

  Reconstruction of anterior column according to the proximal-to-distal rule

  
  
• 
  

  Reduction of posterior column against the reconstructed anterior column followed by fixation of the posterior column using posterior column screw(s)

First Step: Iliac Fossa Debridement

The main principle consists of adequate debridement of all fracture surfaces, starting peripherally at the iliac crest and extending to the interspinous gap. This is followed by a step-by-step direct and indirect reduction of the iliac wing.

Typically, a fracture line extends to the iliac crest. Occasionally, a complete iliac wing fragment can be present. These fractures are mobilized and cleaned. In the presence of an incomplete fracture at the iliac crest, it can be necessary to allow mobilization of this fracture to enable performance of an iliac crest osteotomy to avoid significant impairments in fracture debridement and reduction (▶ Fig. 17.6).

Thereafter, reduction of the iliac fossa fracture lines is performed. Often, digital reduction can already be sufficiently performed. Fracture compression and retention is performed using pointed reduction forceps (Weller or Backhaus clamps) (▶ Fig. 17.7).

For better manipulation of the anterior column fragment, the Farabeuf forceps or the large (asymmetric) reduction forceps are recommended. Because these forceps are positioned on the inner and outer side of the ilium, an additional incision of the gluteal fascia with slight subperiosteal dissection is necessary.

The exact normal contour of the iliac crest has to be restored. In doubt, further lateral dissection is performed for visual reduction control.

If the reduction is incomplete, an ad latus offset remains between the (intact) iliac fragment connected to the SI joint and the unstable anterior column fragment.

This offset can be reduced by inserting a Hohmann retractor into the fracture line and then performing a Kapandji maneuver.

The classical displacement of the anterior column fragment consists of a medialization. The retractor is positioned from inside the iliac fossa through the fracture gap and, by tilting, reduction is performed against the intact posterior ilium.

Second Step: Fixation at the Iliac Crest

Fixation of the iliac crest fracture line is usually performed with long 3.5-mm cortical screws perpendicular to the fracture line in the voluminous portion just below crest. Screw lengths of > 50 mm are regularly possible (▶ Fig. 17.8).

Alternatively, an anatomically contoured reconstruction plate is fixed from the inside the iliac fossa just below the iliac crest line. Screw lengths are, however, very short. In elderly patients with osteoporosis, standard screws are often insufficient. Therefore, plates with locking head screws are considered an optimal option.

Third Step: Fixation of Iliac Fossa Key Fragments

Free fragments, which are often seen near the linea terminalis, have to be anatomically reduced and fixed. This is also performed using 3.5-mm screws or temporarily with K-wires. Alternatively, a small one-third tubular plate can support the reduction by opposing the classic external rotation forces of the iliac fossa displacement (▶ Fig. 17.9).

Fourth Step: Reduction the Main Anterior Column Fragment

The main fracture line of the anterior column is usually close to the linea terminalis and medially just below the entrance level of the true pelvis (▶ Fig. 17.10). Typically, an external rotational deformity of the partially reconstructed fragment is observed with cranial displacement and external rotation. Thus, reduction has to be performed by cranial pressure force in internal rotation. The medially displaced femoral head can interfere with this reduction maneuver. Therefore, femoral head reduction into its anatomical position is crucial. This is performed by percutaneously inserting a Schanz screw into the femoral neck, thus allowing lateral pull of the centrally subluxated femoral head to its anatomical position. Sometimes, an additional longitudinal pull has to be performed. Thereafter, reduction of the main anterior column fragment can be easily performed by pushing the fragment into internal rotation using a ball spike pusher perpendicular to the fracture line at the line at the terminalis in direction to the true pelvis (▶ Fig. 17.10).

Related posts:

Epidemiology Classification of Acetabulum Fractures Indications and Planning T-Type Fractures Approaches Radiological Diagnostics

Stay updated, free articles. Join our Telegram channel

Join