Femoral Neck Fractures: Reduction and Fixation

6 Femoral Neck Fractures


Reduction and Fixation






Classification


There are several comprehensive classification systems for femoral neck fractures and related prognostic factors such as femoral head necrosis, fracture nonunion, and fracture stability. The best-known classification systems are those of Garden (1964) and Pauwels (1935).3,4



Historical Background


Many investigators have devised classification schemes for femoral neck fractures that indicate prognostic differences according to fracture type. The first classification of femoral neck fractures was published in 1823 by Cooper, who divided these injuries into intracapsular and extracapsular fractures.5 Waldenström in 1924 and Cotton in 1927 classified these injuries as either abduction fractures and adduction fractures, according to their displacement features.6,7 In 1955, Watson-Jones developed a system based on the age of the patient. He concluded that certain fracture types were typical in certain age groups.8 Enduring and meaningful classification systems were finally developed by Pauwels in 1935, Linton in 1941, and Garden in 1961.3,4,9,10



Classification System of Garden


In 1964, Garden et al created a classification system for femoral neck fractures that consisted of four fracture types (Garden I to Garden IV), depending on the position and displacement of the femoral head in the anteroposterior (AP) projection (Fig. 6-1). In this system, type I includes fractures with an incomplete fracture line through the femoral neck and valgus position of the proximal fragment, type II comprises fractures with a complete fracture line through the femoral neck and no displacement between the proximal and distal fragments, type III includes fractures with a complete fracture line through the femoral neck and varus displacement of the proximal fragment that is less than 50% of the femoral neck diameter, and type IV comprises fractures with varus displacement of more than 50% of the femoral neck diameter or complete dissociation of the proximal and distal fragments.



This classification scheme provides information about the likelihood of developing avascular femoral head necrosis. Patients with type I fractures have a probability of femoral head necrosis of less than 5%. In type II fractures, the likelihood of this complication is less than 10%. However, the probability of avascular necrosis is more than 50% in type III fractures and more than 80% in type IV fractures. The Garden classification is still the most important and commonly used scheme to classify femoral neck fractures and to determine individual strategies for treatment of these injuries.






Diagnosis


For adequate diagnosis of femoral neck fractures, a thorough clinical examination is performed, and complementary radiographic studies are obtained. Common clinical characteristics of patients with femoral neck fractures include shortening and external rotation of the affected limb, pain during active and passive mobilization, and an inability to walk or to raise the outstretched leg from the surface.


Although these features are seen in most patients with femoral neck fractures, not all patients have this clinical presentation. For example, in patients with incomplete abduction fractures with valgus impaction or stress fractures without any displacement, these characteristics may be notably diminished or even absent. A detailed patient interview and history, as well as a complete review of the patient’s medical records, may aid in the diagnosis of suspected pathologic fractures or fractures secondary to irradiation.






Nonoperative Treatment


Nonsurgical management of intracapsular hip fractures is limited. Occasionally, nonsurgical treatment may be indicated for debilitated, demented, or nonambulatory bedridden patients or for patients whose medical condition carries a high risk of mortality from surgery and anesthesia.


In some cases, nonsurgical treatment can also be an option in patients with undisplaced impacted valgus fractures classified as Garden type I or Pauwels type I. Impaction must be evident on both AP and true lateral radiographic views, and axial alignment of the femoral neck must also be intact. Nonoperative management begins with bed rest and exercises in bed until the pain subsides. Gradual mobilization begins with transfer to a chair, walking without weight bearing with crutches or other walking aids, and later walking with partial weight bearing. After 6 to 8 weeks, full weight bearing can be started. Radiographs should be taken regularly, especially at the beginning of mobilization, after partial weight bearing, and before full weight bearing. In literature, outcome after nonoperatively treated impacted fractures is still controversial. Raaymakers et al reported satisfactory results after conservative treatment, but they also reported a high rate of secondary fracture displacement, especially in elderly patients.11,12 These investigators found secondary instability in 41% of patients more than 70 years of age, but only in 7% of healthy patients less than 70 years of age. Shuqiang et al also found secondary displacement in 41% of their patients, and the highest displacement rate was at age 60 to 80 years.13 Bentley, Hilleboe et al, and Jensen and Hogh showed a fracture displacement or disimpaction rate of 10% to 27% with conservative treatment.1416 Raaymakers et al also found a high correlation between comorbidity and secondary instability.11 Verheyen et al stated that the stability of the fracture depended on several intrinsic and extrinsic factors such as age, comorbidity, Pauwels angle, and retroversion.17


Because of these results, more and more investigators have recommended primary operative stabilization of impacted fractures. When there are no comorbidities representing an increased risk for surgery, most surgeons feel confident about implementing a strategy of prophylactic internal fixation in patients with impacted or nondisplaced femoral neck fractures.

Aug 24, 2016 | Posted by in ORTHOPEDIC | Comments Off on Femoral Neck Fractures: Reduction and Fixation
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