3.1 Clinical evaluation

In GAF, individual goals of treatment and the approach largely depend on patient-related factors, so the clinical evaluation must extend beyond the routine history and physical examination. The following patient-related factors should be thoroughly assessed before treatment options are considered:

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  Preinjury ambulatory status

  
  
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  Functional demands

  
  
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  Independence in activities of daily living

  
  
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  Medical comorbidities

  
  
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  Cognitive status

  
  
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  Bone quality

  
  
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  Preexisting osteoarthritis of the affected hip

  
  
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  Concomitant injuries, especially those with an impact on postoperative mobilization plans

The optimal treatment strategy for an individual patient must be chosen considering factors related to both fracture and patient to provide the best possible clinical outcome. The primary goals in the treatment of GAF are prompt and adequate single-staged treatment (“single-shot surgery”) allowing for early mobilization and avoiding morbidity and mortality associated with prolonged bed rest and subsequent revision surgery.

3.2 Imaging

3.2.2 Computed tomographic scan

Computed tomography (CT) is the gold standard for the evaluation of acetabular fractures, and multiplanar CT reconstructions are mandatory for understanding the exact acetabular fracture pattern [8, 9]. CT imaging of the pelvis allows for proper assessment of the following parameters:

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  Detailed fracture line characteristics and type of acetabular fracture ( Case 1: Fig 3.8-2 )

  
  
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  Extent of anterior and posterior wall comminution and/or marginal impaction

  
  
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  Impaction of the weight-bearing acetabular dome and of the femoral head ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6 )

  
  
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  Articular surface congruity

  
  
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  Subtle subluxation/medialization of the femoral head ( Case 3: Fig 3.8-4 )

  
  
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  Intraarticular bony fragments

Furthermore, modern CT permits manual multiplanar 2-D reconstruction in any arbitrary plane. Additional manual reconstructions complement the information gained from standard axial, coronal, and sagittal planes.

4.1 Classification of Letournel and Judet

The classification system of Letournel and Judet is the most widely used and represents an anatomical and radiographic description of acetabular fracture patterns [12]. This system divides acetabular fractures into two groups, ie, basic and associated fractures, with five fracture subtypes in each group. Basic fracture patterns include posterior wall fractures, posterior column fractures, anterior wall fractures, anterior column fractures, and transverse fractures. Associated fracture patterns include T-shaped fractures, posterior column with posterior wall fractures, transverse with posterior wall fractures, anterior column with posterior hemitransverse fractures and two-column fractures. While the AO/OTA or Tile classification of pelvic ring injuries is limited in its use for the assessment of geriatric pelvic ring injuries (see chapter 3.7 Pelvic ring), the commonly used classification systems for acetabular fractures (Letournel and AO/OTA classifications) are valuable for the assessment of GAF as well. The distribution of acetabular fracture patterns in older adults differs significantly from younger patients, with fracture types involving the anterior column being much more common ( Fig 3.8-1 ).

4.2 AO/OTA Fracture and Dislocation Classification

The alphanumeric AO/OTA classification of acetabular fractures is based on the classification of Letournel and Judet, but includes additional modifiers, making it more complex and less commonly used in daily practice. The AO/OTA classification distinguishes between type A (partial articular fractures with one column involved: A1, posterior wall; A2, posterior column; A3, anterior wall or anterior column), type B (a portion of the acetabular articular surface is in osseous continuity with the iliac bone: B1, transverse; B2, T-shaped; B3, anterior column and posterior hemitransverse) and type C (fracture patterns with no osseous continuity between the acetabular articular surface and the iliac bone: different subtypes of two-column fractures).

4.3 Typical fracture types in geriatric patients

Geriatric acetabular fractures show less variation than acetabular fractures in younger patients due to more uniform injury mechanisms. The incidence of anterior column and wall fractures as well as anterior column with posterior hemitransverse fractures is significantly higher in these patients than in younger populations [4]. Additionally, radiographic findings associated with poor outcome, such as superomedial dome impaction (gull sign) ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6 ), comminution, and marginal impaction in posterior wall fractures and femoral head impactions are more commonly seen in geriatric patients [4].

A characteristic fracture type in geriatric patients is the anterior column with posterior hemitransverse fracture ( Case 1: Fig 3.8-2, Case 3: Fig 3.8-4, Case 5: Fig 3.8-6, Case 6: Fig 3.8-7, Case 8: Fig 3.8-9 ). In these fractures the anterior column is often multifragmentary or comminuted ( Case 5: Fig 3.8-6 ), while the posterior hemitransverse fracture is simple and frequently undisplaced ( Case 1: Fig 3.8-2 ). The quadrilateral plate is generally in osseous continuity with the posterior column ( Case 5: Fig 3.8-6 ). Due to the medial protrusion of the femoral head with medialization of the quadrilateral plate, the posterior column is typically internally rotated. This mechanism is comparable to the opening of a swinging door by the femoral head and is called “open door injury” by the authors in analogy to the “open book injury” of the pelvic ring.

5.1 General remarks

In younger patients, we strive for fracture healing in an anatomical position. Thus, displaced fractures generally require open reduction and internal fixation. The overall goals in the treatment of GAF are as follows:

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  Rapid restoration of the hip function by an adequate single-staged treatment (single-shot surgery) to allow for early mobilization with weight bearing as tolerated

  
  
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  Avoidance of the morbidity and mortality associated with bed rest and/or revision surgery [13, 14]

Treatment options for GAF include:

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  Nonoperative treatment ( Case 1: Fig 3.8-2, Case 2: Fig 3.8-3 )

  
  
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  Internal fixation ( Case 4: Fig 3.8-5 )

  
  
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  Hip arthroplasty ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6 )

  
  
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  Combinations of internal fixation and arthroplasty ( Case 6: Fig 3.8-7, Case 7: Fig 3.8-8 )

The exact roles of the different treatment strategies have not yet been clearly defined as there is a paucity of adequately powered randomized or other prospective studies. Parameters which need to be addressed during decision making include fracture type, age, comorbidities, activity level, osteoporosis, and preexisting osteoarthritis. Orthogeriatric comanagement is necessary for optimal practice. Generally, the delay between trauma and operative intervention should be minimized. The operative treatment of GAF, however, requires special skills and an appropriate level of experience. A delay until operative treatment may be justified if no experienced surgeon is immediately available [13, 14].

5.2 Nonoperative versus operative treatment

The appraisal of joint instability, rather than joint congruency in younger patients, represents an important factor in the decision-making process. Instability is often positively correlated with pain and the inability to ambulate. In unclear situations, an attempt to mobilize the patient with adequate pain management and close monitoring is often made. Failure makes a strong case for operative stabilization ( Case 3: Fig 3.8-4 ).

For the assessment of fracture stability, it is more important to assess the acetabular columns rather than the acetabular walls. While displaced acetabular walls need operative intervention in young patients, this may not be true for geriatric patients. A displacement of a few millimeters may be tolerated if the femoral head remains centered during weight bearing ( Case 1: Fig 3.8-2 ). Regular follow-up x-rays are therefore necessary in these cases in order to detect additional displacement ( Case 3: Fig 3.8-4 ). A displacement of only a few millimeters of the acetabular columns is relevant and indicates a higher degree of instability. These fractures typically require operative treatment ( Case 7: Fig 3.8-8 ). Nondisplaced fractures of the columns as well as nondisplaced transverse or hemitransverse fractures may be treated nonoperatively with weight bearing as tolerated ( Case 1: Fig 3.8-2, Case 2: Fig 3.8-3 ). Operative treatment is usually indicated in fractures with subluxation or dislocation of the hip joint, even in patients in a poor general condition, in order to facilitate nursing care and mobilization ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6 ). Nonoperative treatment of unstable fractures with prolonged bed rest or skeletal traction leads to poor functional results and complications due to immobilization and should be avoided in the treatment of GAF [15].

5.3 Internal fixation versus arthroplasty

Due to a lack of adequate trial data, the decision to employ internal fixation or arthroplasty mainly depends on the surgeon′s preference, experience, and personal skills [16–18]. New prosthetic fixation concepts for the acetabular components, such as angular stable reinforcement rings ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6, Case 8: Fig 3.8-9 ), and their further development will increase the relevance of primary arthroplasty for GAF.

A 2-stage procedure with initial internal fixation and secondary hip arthroplasty after osseous consolidation of the fracture in the situation of symptomatic posttraumatic osteoarthritis is a standard procedure in the treatment of acetabular fractures in nongeriatric patients. In geriatric patients, however, the concept of single-shot surgery, ie, a single operative intervention in the first days after trauma as a definitive solution, should be applied in order to reduce the number of operative interventions and the overall rehabilitation time. Accordingly, primary hip arthroplasty is an enticing concept for the treatment of geriatric acetabular fractures. The major challenge of primary total hip arthroplasty (THA) is the fixation of the cup in the fractured acetabulum. Revision cups and acetabular reinforcement rings and combinations with internal fixation are frequently required.

Primary arthroplasty may be considered in the following situations:

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  Fragile patients with limited mobility ( Case 3: Fig 3.8-4 )

  
  
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  Comminuted fractures ( Case 5: Fig 3.8-6 )

  
  
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  Impaction zones of the acetabular dome (gull sign) ( Case 3: Fig 3.8-4, Case 5: Fig 3.8-6 )

  
  
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  Severe osteoporosis ( Case 8: Fig 3.8-9 )

  
  
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  Preexisting osteoarthritis ( Case 7: Fig 3.8-8 )

  
  
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  Fractures that would require extensive surgery or combined approaches ( Case 5: Fig 3.8-6 )

  
  
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  Acetabular fractures after femoral hemiarthroplasty ( Case 8: Fig 3.8-9 )

  
  
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  Periprosthetic acetabular fractures ( Case 9: Fig 3.8-10 )