Acetabular fractures in geriatric patients: epidemiology, pathomechanism, classification and treatment options

Abstract

The incidence of geriatric acetabular fractures has shown a sharp increase in the last decades. The majority of patients are male, which is different to other osteoporotic fractures. The typical pathomechanism generally differs from acetabular fractures in young patients regarding both the direction and the amount of force transmission to the acetabulum via the femoral head. Geriatric fractures very frequently involve anterior structures of the acetabulum, while the posterior wall is less frequently involved. The anterior column and posterior hemitransverse (ACPHT) fracture is the most common fracture type. Superomedial dome impactions (gull sign) are a frequent feature in geriatric acetabular fractures as well. Treatment options include nonoperative treatment, internal fixation and arthoplasty. Nonoperative treatment includes rapid mobilisation and full weighbearing under analgesia and is advisable in non- or minimally displaced fractures without subluxation of the hip joint and without positive gull sign. Open reduction and internal fixation of geriatric acetabular fractures leads to good or excellent results, if anatomic reduction is achieved intraoperatively and loss of reduction does not occur postoperatively. Primary arthroplasty of geriatric acetabular fractures is a treatment option, which does not require anatomic reduction, allows for immediate postoperative full weightbearing and obviates several complications, which are associated with internal fixation. The major issue is the fixation of the acetabular cup in the fractured bone. Primary cups, reinforcement rings or a combination of arthroplasty and internal fixation may be applied depending on the acetabular fracture type.

Keywords: Anterior column and posterior hemitransverse fracture; Geriatric acetabular fracture; Gull sign; Internal fixation; Primary arthroplasty.

Fig. 1

a Injury mechanism of ACPHT fractures: (1) Force transmission via the greater trochanter. (2) Direction of the force vector to the anterior and superior part of the acetabulum. (3) Fracture between the anterior column and the medial wall. (4) Posterior hemitransverse fracture and internal rotation of the posterior column. b Typical fracture characteristics of ACPHT fractures: multifragmentary anterior column fracture, superomedial articular impaction (“gull sign”), medial wall and posterior column in osseous continuity, simple posterior hemitransverse fracture, internal rotation of the posterior column and the medial wall

Fig. 2

Superomedial dome impactions aka “gull sign”. The name is derived from the typical schematic drawing of gulls by children

Fig. 3

a Minimally displaced ACPHT fracture without gull sign. The fracture healed without further displacement after nonoperative treatment. b Minimally displaced ACPHT fracture with gull sign. Nonoperative treatment resulted in massive pain and further subluxation. Primary arthroplasty was performed after eight days

Fig. 4

a Unreduced superomedial dome impaction after reduction of the anterior column and temporary wire fixation. b Improved reduction of the superomedial dome impaction, but with a remaining moderate gull sign and a high risk of loss of reduction in geriatric patients

Fig. 5

a Posterior hip dislocation with posterior wall fracture and femoral head impaction in an 86 year old female. b Primary arthoplasty without reinforcement rings or additional internal fixation using a double mobility system

Fig. 6

a ACPHT fracture with gull sign. The superolateral dome is intact and in osseous continuity with the supracetabular bone and the iliac wing. b Primary arthoplasty of ACPHT fractures using angular stable reinforcement rings. X-ray control after five years (right) and one year (left)

Fig. 7

a Both-column fractures are defined as fractures with a bony separation of the entire acetabulum from the remaining iliac bone. b In geriatric both-colum fractures the supracetabular fracture components are frequently incomplete and undisplaced and therefore inherently stable