Femoral Head Fractures: Pipkin IV

Several classification systems are available regarding femoral head fractures. The most commonly used classification system is that of Pipkin (▶ Table 24.1), which is based on standard radiographic analysis without using CT or MRI data.¹

**Table 24.1** Classification according to Pipkin
Type	Description
1	Dislocation associated with a fracture of the femoral head caudad to the fovea capitis femoris
2	Dislocation with an associated fracture of the femoral head cephalad to the fovea capitis femoris
3	Type I or II injury associated with a fracture of the femoral neck
4	Type I or II injury associated with a fracture of the acetabular rim

Brumback further specified this classification (▶ Table 24.2) and integrated the anterior and central fracture dislocation types, the size of the posterior acetabular involvement, and the instability of the hip.²

**Table 24.2** Classification according to Brumback
Type	Description
1	Posterior hip dislocation with femoral head fracture involving the inferomedial non–weight-bearing portion of the femoral head
1A	With minimum or no fracture of the acetabular rim and stable hip joint after reduction
1B	With significant acetabular fracture and hip joint instability
2	Posterior hip dislocation with femoral head fracture involving the superomedial non–weight-bearing portion of the femoral head
2A	With minimum or no fracture of the acetabular rim and stable hip joint after reduction
2B	With significant acetabular fracture and hip joint instability
3	Dislocation of the hip (unspecified direction) with associated femoral neck fracture
3A	Without fracture of the femoral head
3B	With fracture of the femoral head
4	Anterior dislocation of the hip with fracture of the femoral head
4A	Indentation type: depression of the superolateral weight-bearing surface of the femoral head
4B	Transchondral type: osteocartilaginous shear fracture of the weight-bearing surface of the femoral head
5	Central fracture dislocation of the hip with fracture of the femoral head

Recently, Chiron et al integrated osteochondral injuries and femoral head impaction injuries in their classification (▶ Table 24.3).³^,⁴

**Table 24.3** Classification according to Chiron
Type	Description
1	Osteochondral fragments
2	One-fourth head fragment
3	One-third head fragment
4	One-half head fragment
5	Superior collapse

Several overview reports address injury mechanism, primary emergency treatment, general treatment recommendations, and complications.³^,⁵^,⁶

The literature on femoral head fractures is controversial as many analyses fail to analyze specific fracture types and report summarizing results of different Pipkin fracture types.⁷^,⁸^,⁹ In an analysis of 14 cases of all fracture types, 78% good and excellent results were reported.¹⁰ In a meta-analysis by Giannoudis et al, integrating 450 patients, it was stated that fragment excision was superior to open reduction and internal fixation (ORIF) in Pipkin type I injuries, whereas ORIF was proposed in type II fractures.¹¹ In an analysis of 110 patients with all fracture types, no treatment mode was found to be superior. Overall, after a mean of 6 months, in almost 20% of patients, secondary total hip replacement (THR) was necessary.⁴ Recently, an analysis of 24 Pipkin type I cases stated that fragment excision was superior to pure reduction¹² and a further analysis of 37 cases of all fracture types reported 67% good and excellent results.¹³ Interestingly, Giannoudis et al reported an effect of the size of the fragment, with worse results with smaller fragments (type I vs. type II).¹¹

Overall, in the meta-analysis of Giannoudis et al, the long-term results were independent of the treatment type. After nonoperative treatment, 63.1% good and excellent results were reported, after fragment excision 65% good and excellent results, after ORIF 61.6%, and after primary THR 60% good and excellent results were observed.¹¹

Additionally, the optimal approach is still under debate,¹³^,¹⁴^,¹⁵^,¹⁶^,¹⁷ not favoring either an anterior or posterior approach. The concept of surgical hip dislocation has become increasingly relevant.

Clinical Relevance

In isolated Pipkin type I or II fractures, approximately 60–80% good and excellent results can be expected.⁴^,¹⁰^,¹³

A literature review of different reports from 1974 until 2007, including German literature, identified 325 femoral head fractures with sufficient data.¹⁶^,¹⁸^,¹⁹^,²⁰^,²¹^,²²^,²³^,²⁴^,²⁵^,²⁶^,²⁷^,²⁸^,²⁹^,³⁰^,³¹^,³²^,³³^,³⁴^,³⁵^,³⁶^,³⁷^,³⁸^,³⁹^,⁴⁰^,⁴¹^,⁴²^,⁴³^,⁴⁴

Overall, 106 Pipkin I fractures, 104 Pipkin II fractures, 23 Pipkin III fractures, and 92 Pipkin IV fractures with relevant treatment parameters could be identified. Type IV fractures were observed in 28.3%.

Recent analyses stated that type IV femoral head fractures, consisting of a femoral head fracture in combination with an acetabular fracture (most commonly a posterior wall fracture or a posterior rim avulsion), can be expected in approximately 30%. Giannoudis et al performed a literature review on Pipkin fractures and concluded that Pipkin type IV fractures can be expected in 30% of all Pipkin fractures.¹¹ According to the Chiron classification, 34.4% of femoral head injuries were Pipkin type IV injuries in an analysis of 55 patients³ and, in an analysis of the same group, a rate of 27.3% type IV fractures were reported⁴ but Scolaro et al observed this fracture type in only 15%.⁹

Clinical Relevance

Pipkin type IV fractures account for approximately 30% of all femoral head fractures.

24.2 Data on Pipkin Type I Fractures

The literature review on 325 femoral head fractures identified 106 type I fractures.¹⁶^,¹⁸^,¹⁹^,²⁰^,²¹^,²²^,²³^,²⁴^,²⁵^,²⁶^,²⁷^,²⁸^,²⁹^,³⁰^,³¹^,³²^,³³^,³⁴^,³⁵^,³⁶^,³⁷^,³⁸^,³⁹^,⁴⁰^,⁴¹^,⁴²^,⁴³^,⁴⁴ Treatment consisted of 29 isolated reductions, 39 fragment resections, and 34 screw osteosyntheses of the femoral head. One patient had a K-wire fixation and three patients had primary femoral head replacement (one bipolar prosthesis, two THR). Reduction of the dislocated femoral head within 6 hours led to superior clinical and radiological results. The long-term results according to the Thompson/Epstein and/or Merle d’Aubigné criteria were as follows:

After isolated closed reductions after a mean of 92.5 months, 75% had good and excellent clinical and 74% radiological results, respectively
After fragment excision after a mean of 92.5 months, 64% had good and excellent clinical and 76% radiological results, respectively
After screw osteosynthesis, 69% had good and excellent clinical and 72% radiological results, respectively

Analysis of the chosen approach (anterior vs. posterior) indicated that posterior approaches were associated with better clinical and radiological results.

Recently, Chen et al analyzed 16 patients, comparing eight patients with only closed reduction and eight patients treated with fragment excision.

According to the Thompson and Epstein score and the Merle d’Aubigné score, after fragment excision, 87.5% had good and excellent clinical and radiographical results (follow-up 39 months, 0% avascular necrosis (AVN), one grade III heterotopic ossification) compared to 50% after isolated closed reduction (follow-up 39 months, 25% AVN).⁴⁵

Clinical Relevance

In Pipkin type I, all treatment modalities are performed in comparable frequencies. Early reduction of a dislocated hip is advantageous. The clinical result is not treatment dependent, with a tendency to favor fragment excision. A posterior approach should be preferred.

24.3 Data on Pipkin Type II Fractures

The literature review on 325 femoral head fractures identified 104 type II fractures.¹⁶^,¹⁸^,¹⁹^,²⁰^,²¹^,²²^,²³^,²⁴^,²⁵^,²⁶^,²⁷^,²⁸^,²⁹^,³⁰^,³¹^,³²^,³³^,³⁴^,³⁵^,³⁶^,³⁷^,³⁸^,³⁹^,⁴⁰^,⁴¹^,⁴²^,⁴³^,⁴⁴ Treatment consisted of 24 isolated reductions, 11 fragment resections, and 64 screw osteosyntheses of the femoral head. Five patients had primary femoral head replacement (one bipolar prosthesis, four THR). The long-term results according to the Thompson/Epstein⁴⁶ and/or Merle d’Aubigné criteria⁴⁷ were as follows:

After isolated closed reductions after a mean of 71 months, 76% had good and excellent clinical and 76% radiological results, respectively
After fragment excision after a mean of 46 months, 54% had good and excellent clinical and 63% radiological results, respectively
After screw osteosynthesis after a mean of 38 months, 77% had good and excellent clinical and 78% radiological results, respectively

Data on the performed approaches were available in 40 patients. In 11 patients, the Smith-Peterson approach was performed, in seven patients an anterolateral approach, in six a straight lateral, in six the Kocher-Langenbeck, and in 10 the Kocher-Langenbeck + surgical hip dislocation approach was performed. Overall, the approach did not influence results.

Clinical Relevance

Only gold members can continue reading. Log In or Register to continue