Fractures of the femoral head: a narrative review

Abstract

Fractures of the femoral head are rare injuries, which typically occur after posterior hip dislocation.The Pipkin classification, developed in 1957, is the most commonly used classification scheme to date.The injury is mostly caused by high-energy trauma, such as motor vehicle accidents or falls from a significant height.Emergency treatment consists of urgent closed reduction of the hip joint, followed by non-operative or operative treatment of the femoral head fracture and any associated injuries.There is an ongoing controversy about the suitable surgical approach (anterior vs. posterior) for addressing fractures of the femoral head. Fracture location, degree of displacement, joint congruity and the presence of loose fragments, as well as concomitant injuries are crucial factors in choosing the adequate surgical approach.Long-term complications such as osteonecrosis of the femoral head, posttraumatic osteoarthritis and heterotopic ossification can lead to a relatively poor functional outcome. Cite this article: EFORT Open Rev 2021;6:1122-1131. DOI: 10.1302/2058-5241.6.210034.

Keywords: Pipkin; classification; femoral head; fracture; surgical approach.

Fig. 1

The Pipkin classification. (A) Type I: femoral head fracture inferior to the fovea centralis. The ligamentum capitis femoris inserting in the fovea centralis is shown. (B) Type II: femoral head fracture superior to the fovea centralis. (C) Type III: femoral head fracture inferior or superior to the fovea centrals with an associated femoral neck fracture. (D) Type IV: femoral head fracture inferior or superior to the fovea centrals with an associated acetabular fracture.

Fig. 2

Treatment algorithm in the emergency phase. Upon clinical suspicion of a femoral head fracture after posterior hip dislocation, thorough neurovascular assessment has to be performed. Afterwards, radiographs of the hip and pelvis can confirm the diagnosis. Rapid closed reduction should be performed as soon as possible. If closed reduction is successful, novel imaging by means of radiographs and CT scans must be performed to evaluate the definitive treatment approach. If closed reduction is unsuccessful or contraindications for closed reduction are present (e.g. femoral neck fractures), urgent open reduction in the operating room is indicated. CT scans for completing diagnostics should performed if possible; however, they must not hinder rapid surgical treatment. Note. CT, computed tomography.

Fig. 3

Treatment algorithm according to the Pipkin classification. In Pipkin type I and type II fractures, the treatment depends on the degree of displacement after closed reduction. For fractures with a displacement of less than 1 mm a non-operative approach should be considered. Fractures with a displacement of more than 1 mm should be addressed with open reduction and internal fixation (ORIF) or fragment removal. In Pipkin type III fractures, surgical treatment depends on signs of arthritis in the hip joint and the physical demands of the patient. If advanced signs of arthritis or immobilization are evident, a bipolar endoprosthesis or total hip arthroplasty are advised. If not, ORIF with surgical hip dislocation is suggested, attempting to preserve the femoral head, especially in younger patients. In Pipkin type IV fractures with non-displaced and small fracture segments, a non-operative approach with weight-bearing of the hip joint is recommended. Displaced and large fracture segments are usually treated with ORIF by the Kocher-Langenbeck approach with or without trochanteric-flip osteotomy.

Fig. 4

Algorithm for surgical approaches. For Pipkin type I and II fractures, the anteromedial Smith-Peterson approach represents the preferred surgical exposure. For Pipkin III fractures the Smith-Peterson and the anterolateral Watson-Jones approach is recommended. Pipkin IV injuries with concomitant acetabular fractures of the anterior column should be addressed using the Stoppa approach with Smith-Peterson extension. Pipkin IV fractures with injuries of the posterior column or posterior fragment dislocation should be treated with the Kocher-Langenbeck approach or the modified Gibson approach in combination with trochanter osteotomy.