- Femoral Head Fractures: An OverviewSimon CE Jones, Rohit Rambani, Hemant K Sharma
- Operative Management of Femoral Head Fractures: Surgical Dislocation of Hip and Screw FixationLalit Maini, Sumit Banerjee
Introduction
Fractures of the femoral head are uncommon injuries that present significant challenges to the treating surgeon. Most femoral head fractures are associated with posterior hip dislocation, although isolated fractures and those associated with anterior dislocation are also reported. Femoral head fractures complicate 4–17% of posterior hip dislocations.1 Management centers on the basic principles of treating intra-articular fractures by restoring joint congruity and the stability of the hip joint. There is equally a role for arthroplasty in selected patients. Due to the rarity of these injuries there is a relative paucity of information available in the literature and no clearly defined treatment strategy has been agreed upon.
Epidemiology
Femoral head fractures are most commonly seen in young men (mean age 38.9 years) and are the result of high-energy injuries usually motor vehicle accidents.2 They are frequently caused by dashboard injuries where a longitudinal force is applied across the hip joint. They are also associated with anterior dislocation of the hip joint.
Etiology and Pathoanatomy
In cases where the femoral head fracture is caused due to dashboard injuries, the hip is flexed and abducted, more force is generated at the femoral head and posterior acetabular wall where axial compression occurs and therefore fracture can result.
Fractures of the femoral head caused this way are often of the shear type. In contrast fractures associated with anterior dislocation are usually of the indentation type caused by the femoral head colliding with the acetabular rim. The mechanism for these injuries is one of abduction and extension.
These fractures are associated with a tear in the hip capsule in the direction of the dislocation. The surrounding muscles and soft tissues are damaged to a varying degree. The sciatic nerve might be stretched/displaced or injured. The retinacular vessels are usually stretched out and may be damaged leading to a high rate of osteonecrosis in these fractures. The fracture produces a variety of fragments ranging from small osteochondral ones to large fragments. The smaller inferior fragments of femoral head are usually free of soft tissue attachments while the larger ones are usually still attached. These pathoanatomic changes should be borne in mind while planning the treatment modality.
Presentation and Assessment
Patients often present following road traffic accidents and have multiple system injures. Indeed, 95% of patients with hip dislocation will have an injury to another part of their body.3 Therefore, when assessing such patients a full trauma examination following ATLS guidelines is mandatory. Injuries of the head, chest, and abdomen are frequently encountered as well as other orthopedic injuries such as fractures of 4the acetabulum, femoral diaphysis, or patella and ligamentous knee injuries. A detailed assessment of the neurovascular status of the limb is also required as the sciatic nerve may be compromised.
Radiological assessment initially consists of an anteroposterior (AP) pelvic X-ray, although further imaging may be needed for multiply injured patients. The AP X-ray should demonstrate the femoral head fracture and dislocation, although small intra-articular fragments may not be seen. CT scans are performed to assess the fracture pattern of the femoral head or any associated acetabular injury and to highlight any intra-articular fragments. The CT scan should be performed after reduction of any associated hip dislocation.
Classification
The most commonly used classification for femoral head fractures is that of Pipkin. He described his classification in 1957.4 His classification subdivided the Stewart and Milford grade IV injuries, which were dislocations of the hip with fracture of the femoral head or neck of the femur, into four types (Table 1.1).
A further more extensive classification was proposed by Brumback in 1987, which encompasses the direction of the dislocation, the femoral head fragment and the stability of the hip.5 There are five types, four of which are subdivided into type A or B.
Brumback's Classification
Type 1 | Posterior hip dislocation with fracture of the inferomedial portion of the femoral head |
Type 1A | With minimum or no fracture of the acetabular rim and stable hip joint after reduction |
Type 1B | With significant acetabular rim fracture and hip instability |
Type 2 | Posterior hip dislocation with fracture of the superomedial portion of the femoral head |
Type 2A | With minimum or no fracture of the acetabular rim and stable hip joint after reduction |
Type 2B | With significant acetabular fracture and hip joint instability |
Type 3 | Dislocated hip (unspecified direction) with femoral neck fracture |
Type 3A | No associated femoral head fracture |
Type 3B | Associated femoral head fracture |
Type 4 | Anterior dislocation of the hip with a femoral head fracture |
Type 4A | With indentation of the superolateral femoral head |
Type 4B | With transchondral shear fracture |
Type 5 A | central fracture dislocation of the hip with a femoral head fracture |
Treatment: Principles and Modalities
The aims of treatment are to achieve joint congruency and stability and to minimize ischemic injury to the femoral head. Femoral head fractures with associated dislocations or femoral neck fractures demand emergent treatment. Dislocations should be reduced with the addition of skeletal traction if required. Further imaging by means of a CT scan can then be obtained.
Ipsilateral femoral head and neck fractures require urgent open reduction and internal fixation. In elderly patients with Pipkin 5type 3 injuries hemiarthroplasty or total hip replacement may be the best option.
Once the hip joint is adequately reduced definitive surgery can be planned. The key elements to be considered are the size of the femoral head fracture fragments, the location of the fracture and the presence of an associated acetabular fracture:
- In Pipkin type 1 fractures, the fragment does not involve the weight-bearing portion of joint surface and if the reduction is good and the fragment is small nonoperative treatment is recommended. If reduction is not adequate then the fragment can be excised if it is small or reduced and fixed if it is of significant size. Fixation can be achieved with small cancellous screws or variable pitch screws (Herbert screws)
- Pipkin type 2 injuries can potentially be treated nonoperatively as long as anatomic reduction is achieved and demonstrated on CT scan. Close radiological observation is required to check for any displacement. Open reduction and internal fixation is usually necessary. It is essential that any screws are placed under the articular surface
- As previously discussed Pipkin type 3 injuries required emergent open reduction and internal fixation. If possible the neck fracture can be fixed with cannulated screws prior to reduction of the hip joint and fixation of the femoral head fracture. In elderly patients with Pipkin type 3 injuries hemiarthroplasty or total hip replacement may be the best option
- Type 4 injuries frequently require combined fixation of the acetabular and femoral head fracture. If the acetabular fracture demands surgical fixation then the femoral head fracture should be stabilized at the same time, even if undisplaced, in order to permit early hip joint movement.
Surgical Approach
Controversy remains over which surgical approach offers the best results. Traditionally, the posterior approach was advocated for the treatment of femoral head fractures associated with posterior dislocation.6 This is to avoid surgical insult to the anterior blood supply in the presence of an already compromised posterior supply. If fixation of the posterior acetabular wall is to be performed then a posterior approach is mandated. More recently the anterior Smith-Petersen approach has been used. This approach affords direct visualization of the anterior fracture fragment with the potential for anatomic reduction and easier fixation. Equally, it has been demonstrated that there is no increase in the rate of avascular necrosis when using the anterior approach.7 Indeed, rates of avascular necrosis are lower in patients treated via the anterior approach.8,9 However, there is a higher incidence of heterotopic ossification when compared to the posterior approach.9 Some centers have recommended the use of a trochanteric flip osteotomy that allows good visualization of the hip joint and anatomical reduction.1,8
There are case reports highlighting the role of arthroscopic surgery in treating femoral head fractures. Arthroscopy has generally been used for the removal of small osteochrondral fragments but the internal fixation of fractures has also been reported. The indications for arthoscopic fixation are limited and should be reserved to surgeons with significant experience in the procedure.10,11
Complications and Outcomes
The majority of complications are related to the high-energy nature of these injuries. The most common long-term sequelae of femoral head fractures are post-traumatic arthritis, heterotopic ossification, and avascular necrosis. A recent systematic review has highlighted the following rates of complications.2
Complications | |
|---|---|
Post-traumatic arthritis | 20% |
Heterotopic ossification | 16.8% |
Avascular necrosis | 11.8% |
Sciatic nerve injury | 3.95% |
Surgical infection | 3.2% |
6Overall, it was found that better outcomes were seen in Pipkin types 1 and 2. Functional outcomes reported in the literature are extremely varied, often in small case series and there is a lack of a consistent outcome measure. Patients with femoral head fractures have a guarded prognosis and should be informed of the possible long-term sequelae and the need for further surgery in the future.
References
- Henle P, Kloen P, Siebenrock KA. Femoral head injuries: which treatment strategy can be recommended. Injury. 2007;38:478–88.
- Giannoudis PV, Kontakis G, Christoforakis Z, et al. Management, complications and clinical results of femoral head fractures. Injury. 2009;40:1245–51.
- Hak DJ, Goulet JA. Severity of injuries associated with traumatic hip dislocation as a result of motor vehicle collisions. J Trauma. 1999;47(1):60–3.
- Pipkin G. Treatment of grade IV fracture-dislocation of the hip. J Bone Joint Surg (Am). 1957;39:1027–42.
- Brumback RJ, Kenzora JE, Levitt LE, et al. Fractures of the femoral head. Hip; 1987.pp.181–206.
- Epstein IIC, Wiss DA, Cozen L. Posterior fracture dislocation of the hip with fractures of the femoral head. Clin Orthop Relat Res. 1985;201:9–17.
- Swiontkowski MF, Thorpe M, Seiler JG, Hansen ST. Operative management of displaced femoral head fractures: case matched comparison of anterior versus posterior approaches for Pipkin I and Pipkin II fractures. J Orthop Trauma. 1992;6(4):437–42.
- Stannard JP, Harris HW, Volgas KA, Alonson JE. Functional outcomes of patients with femoral head fractures associated with hip dislocations. Clin Orthop Relat Res. 2000;377:44–56.
- Guo J, Tang N, Yang HL, Qin L, Leung K. Impact of surgical approach on postoperative heterotopic ossification and avascular necrosis in femoral head fractures: a systematic review. Int Orthop (SICOT). 2010;34:319–22.
- Yamatomoto Y, Ide T, Ono T, Hamada Y. Usefulness of arthroscopic surgery in hip trauma cases. Arthroscopy. 2003;19(3):269–73.
- Matsuda DK. A rare fracture, an even rare treatment: the arthroscopic reduction and internal fixation of an isolated femoral head fracture. Arthroscopy. 2009;25(4):408–12.