Pipkin fracture

Description

Femoral head fractures are relatively uncommon and are typically associated with hip dislocations after severe high-impact trauma such as a motor vehicle collision. Hip fracture-dislocations are clinical emergencies requiring immediate reduction to prevent osteonecrosis.

The first published case was by John Birkett in 1869, and the first review of global literature and early classification by Christopher in 1926.

The Pipkin classification system (1957) is the most-frequently used system for classification of femoral head fractures. The alternate Brumback classification system (1987) is more comprehensive fracture-dislocation classification and takes into account the degree of comminution of the fractured fragments; the size of the head fracture; size of the acetabular fracture; and joint stability.

Pipkin classification of femoral head fracture

Classification system for femoral head fractures usually in association with hip dislocations.

• Type I: Femoral head fracture inferior (distal) to fovea. Usually small fracture not involving the weight-bearing surface
• Type II: Femoral head fracture superior (proximal) to fovea. Larger fracture involving the weight-bearing surface
• Type III: Type I/II femoral head fracture AND fracture of femoral neck. Increased risk of avascular necrosis
• Type IV: Type I/II femoral head fracture AND fracture of acetabulum, most commonly the posterior wall

History of the Pipkin classification

1869 – John Birkett (1815-1904) provided the first published case description of femoral head fracture. Birkett reported the case of a 35-year-old woman who died following a fall from a window. Autopsy demonstrated left hip dislocation with a femoral head fracture.

On further examination it was discovered that a portion of the head of the femur had been broken off. This fragment, to which the greater part of the ligamentum teres was still attached, remained in the acetabulum.

Authorities upon the subject of dislocations of the joints do not even allude to this complication. Malgaigne states “Les luxations du femur ne sont guere compliquees que de fractures soit des os du bassin, soit du femur meme soit d’autres os plus eloignes (The luxations of the femur are but little complicated with fractures, either of the pelvic bones, the femur itself, or more distant bones)” 

Having failed to find a parallel case in the book of Robert W. Smith of Dublin, I wrote to that gentleman who did me the favour to reply as follows “Although tolerably familiar with the literature of fractures and luxations I am not aware of any similar injury having been placed on record as happening to the head of the femur.” 

We have then, probably, under observation an injury hitherto undescribed.

Birkett 1869

1872 – Walter Moxon (1836-1886) performed the autopsy on a man struck by a train. He sustained compound iliac dislocation of the hip with partial avulsion of the femoral head.

At the post-mortem examination a very singular injury was found. A portion of the head of the bone remained in the hip-joint, attached by the round ligament, so that fracture as well as dislocation had occurred. Evidently, on the displacement of the head of the bone, some violent force, taking advantage of the leverage the limb afforded, had forced the head of the femur to plough its way among muscles, the thigh being flexed at the same moment that the bone was carried backward, and whilst it pivoted on the side of the pelvis; none but very enormous violence could effect such a terrible injury.

Moxon 1872

1926 – Frederick Christopher (1889-1967) published a detailed review and analysis of the 14 femoral head fractures published in world literature, which substantially contributed to a better understanding of this injury. He added a case of his own from 1924, a woman who sustained posterior dislocation of the hip associated with avulsion of the inferior part of the femoral head. Closed reduction under general anaesthesia was successful.

1957 – Garrett Pipkin (1904-1981) analysed a group of 25 cases (cases of his own and those of colleagues) and developed his fractures classification system of femoral head fractures (4 Types)

• Type I: Femoral head fracture inferior (distal) to fovea.
• Type II: Femoral head fracture superior (proximal) to fovea.
• Type III: Type I/II femoral head fracture AND fracture of femoral neck.
• Type IV: Type I/II femoral head fracture AND fracture of acetabulum, most commonly the posterior wall

1987 – Robert Joseph Brumback proposed a more comprehensive classification system, taking into account the direction of dislocation and joint stability. The Brumback classification highlights the importance of joint instability, direction of dislocation, and acetabular fracture severity in the prediction of a poorer outcomeAppears to provide prognostic value, with patients sustaining Type IIIB and Type V injuries faring the worst, and patients with Type IIB fractures having the best physical outcomes

• Type I: Posterior hip dislocation, femoral head fracture (inferomedial portion)
  • Type Ia: minimum/ no fracture of the acetabular rim and stable hip joint after reduction.
  • Type Ib: significant acetabular rim and hip joint instability after reduction.
• Type II: Posterior hip dislocation, femoral head fracture (supermedial portion)
  • Type IIa: minimum/ no fracture of the acetabular rim and stable joint after reduction.
  • Type IIb: significant acetabular fracture and hip joint instability after reduction.
• Type III: Dislocation of the hip (unspecified direction) with femoral neck fracture.
  • Type IIIa: Without fracture of the femoral head.
  • Type IIIb: With fracture of the femoral head.
• Type IV: Anterior dislocation of the femoral head.
  • Type IVa: Indentation type; depression of the superolateral surface of the femoral head.
  • Type IVb: Transchondral type; osteocartilaginous shear fracture of the weight-bearing surface of the femoral head.
• Type V: Central fracture-dislocation of the hip with femoral head fracture.

Associated Persons

• John Birkett (1815-1904)
• Walter Moxon (1836-1886)
• Frederick Christopher (1889-1967)
• Garrett Pipkin (1904-1981)

References

• Birkett J. Description of a dislocation of the head of the femur, complicated with its fracture. Medico-Chirurgical Transactions. 1869; 52: 133-140
• Moxon W. Compound dislocation of hip-joint, the bone thrust through skin. The Medical Times and Gazette. 1872; 44(1): 96
• Braun H. Fractur des Schenkelkopfes bei einer Luxatio ischiadica. In: Seltenere Fracture des Oberschenkels. Archiv für klinische chirurgie 1891; 42 :109-111
• Christopher F. Fractures of the head of the femur. Arch Surg. 1926; 12(5): 1049-1061
• Pipkin G. Treatment of grade IV fracture-dislocation of the hip. J Bone Joint Surg Am. 1957; 39-A(5): 1027-42
• Brumback RJ, Kenzora JE, Levitt LE, Burgess AR, Poka A. Fractures of the femoral head. Hip. 1987: 181-206
• Yoon et al. Clinical and radiographic outcome of femoral head fractures: 30 patients followed for 3-10 years. Acta Orthop Scand. 2001 Aug;72(4):348-53.
• Bartoníček J, Rammelt S. History of femoral head fracture and coronal fracture of the femoral condyles. Int Orthop. 2015; 39(6): 1245-50.
• Romeo NM. Classifications in Brief: The Pipkin Classification of Femoral Head Fractures. Clin Orthop Relat Res. 2018; 476(5): 1114–1119.

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