Trauma

Basic Science

Internal Fixation vs. Arthroplasty in Femoral Neck Fractures
Roy Sanders, M.D.
Florida Orthopaedic Institute
Tampa, Florida
October, 2007

The current issues surrounding femoral neck fracture fixation have largely centered on whether or not internal fixation is justified in the elderly. The following is a synopsis of treatment algorithms based on available literature and clinical experience.

Femoral neck fractures, specifically subcapital fractures, were defined by Garden in 1961 as one of four types, each with a different prognostic outcome. These fractures occur just below the femoral head and are all intracapsular fractures; that is, they cannot heal with callus. The biggest risks associated with these fractures are avascular necrosis of the femoral head and nonunion of the neck. This fracture must not be confused with a basic cervical fracture which by definition is extracapsular and does not have the same complications as it is in fact, an intertrochanteric fracture. In the 1980’s, the Toronto group further refined Garden’s classification by creating two groups: A) stable fractures (Garden I/II), and B) unstable fractures (Garden III/IV). This allows us to evaluate outcomes quite clearly and permits more consistent treatment methods. Another type of fracture of importance is the Pauwel’s III, a vertical shear fracture that starts at the superior neck at the base of the head and travels down to the inferior neck, close to the inferior capsular insertion.

Importantly, Garden identified the need to obtain an anatomic reduction coupled with stable fixation. While open reduction is not commonly employed today, stable fixation can be achieved through a variety of implants. The only other variable that has any bearing on outcome is the patient’s physiologic age. By this we mean bone quality and overall health of the patient. Clearly, a 40-year-old alcoholic in renal failure secondary to diabetes will have worse bone quality than a healthy 70 year old that is fit, has no co-morbidities, and plays golf 4 days a week.

Thus our algorithm must evaluate stability and age. Most of the current literature supports the use of internal fixation for stable fractures in both the young and old alike (2;4). Typical, implants include 3 cannulated screws placed into the neck in an inverted V, under fluoroscopic control, with the patient on a fracture table. A wide spread with care to avoid the posterior, superior neck, and capsule is recommended. Asnis et al. had excellent results using this technique, and this has become the standard of care for Garden I and II subcapital fractures (1). Most other authors would agree with this approach (2;3;6;8;9).

In the elderly (>70 years) with a displaced femoral neck fracture (Garden III/IV), the literature is very clear that arthroplasty is superior to internal fixation. There are multifactorial reasons, but in general, internal fixation of displaced fractures in the elderly is associated with high rates of failure due to symptomatic nonunion and avascular necrosis (9). The ability to place a prosthesis as the definitive treatment method and thereby limit the reoperation rate, complication rate, and improve functional outcomes is overwhelming.

The unstable femoral neck fracture in patients under 50 years is almost always treated with attempts at reduction and internal fixation in an effort to maintain their own femoral head. Both Tooke et al. and Haidukewych et al. have shown good outcomes when internal fixation is employed (4;10). In Tooke’s series, patients that developed avascular necrosis did not always have symptoms sufficient to require salvage by arthroplasty. In the series of patients presented by Haidukewych et al., there was an 85% 10-year survival rate of the original internal fixation. Finally, Jain et al. have suggested that in these patients, if a displaced femoral neck fracture is seen in a patient under the age of sixty who is healthy, surgery should be performed in less than 12 hours to possibly minimize the risk of avascular necrosis (5).

When an unstable fracture is encountered in a young patient, an anatomic reduction is critical to obtain. If this is not possible with closed methods, then open reduction using a Smith–Peterson should be considered. Furthermore, while 3 cannulated screws may be adequate for an impacted stable fracture, displaced fractures are often associated with comminution and/or may present as a Pauwel’s III fracture. In both of these instances, a sliding hip screw placed along the calcar with a superiorly placed anti-rotation lag screw may be the superior implant to maintain reduction and obtain healing of the neck (7). Again, although avascular necrosis may occur, this may not be symptomatic for some time to come.

The final question is the one that asks: What do I do with the healthy 70 year old with a displaced femoral neck fracture? Do I fix or replace it? Unfortunately, no one has a good answer to the question of treatment of a displaced neck fracture in the 50 – 75 year age range. While there is ample literature to support whatever argument one wishes to make, most of these series are underpowered and cannot answer the question raised. Therefore the surgeon must answer the following questions: 1) is the patient healthy or are there multiple comorbidities, 2) is the displaced fracture simple or comminuted, 3) can the bone quality tolerate internal fixation, 4) what is the patient’s social situation, and finally, 5) what operation am I most comfortable with; that is, which one can I obtain the best result with. The answer to these 5 questions will define your ultimate treatment, which must be individualized to the patient.

References

1. Asnis SE, Wanek-Sgaglione L. Intracapsular fractures of the femoral neck. Results of cannulated screw fixation. J Bone Joint Surg Am. 1994;76:1793-1803.
   
   
2. Bhandari M, Devereaux PJ, Tornetta P, III, et al. Operative Management of Displaced Femoral Neck Fractures in Elderly Patients. An International Survey.
   J Bone Joint Surg Am. 2005;87:2122-2130.
   
   
3. Blomfeldt R, Tornkvist H, Ponzer S, et al. Comparison of Internal Fixation with Total Hip Replacement for Displaced Femoral Neck Fractures. Randomized, Controlled Trial Performed at Four Years. J Bone Joint Surg Am. 2005;87:1680-1688.
   
   
4. Haidukewych GJ, Rothwell WS, Jacofsky DJ, et al. Operative Treatment of Femoral Neck Fractures in Patients Between the Ages of Fifteen and Fifty Years.
   J Bone Joint Surg Am. 2004;86:1711-1716.
   
   
5. Jain R, Koo M, Kreder HJ, et al. Comparison of early and delayed fixation of subcapital hip fractures in patients sixty years of age or less.
   J Bone Joint Surg Am. 2002;84-A:1605-1612.
   
   
6. Lu-Yao GL, Keller RB, Littenberg B, et al. Outcomes after displaced fractures of the femoral neck. A meta-analysis of one hundred and six published reports. J Bone Joint Surg Am. 1994;76:15-25.
   
   
7. Probe R, Ward R. Internal fixation of femoral neck fractures.
   J Am Acad Orthop Surg. 2006;14:565-571.
   
   
8. Rogmark C, Carlsson A, Johnell O, et al. Arthroplasty Led to Fewer Failures and More Complications Than Did Internal Fixation for Displaced Fractures of the Femoral Neck.
   J Bone Joint Surg Am. 2002;84:2108.
   
   
9. Sikorski JM, Barrington R. Internal fixation versus hemiarthroplasty for the displaced subcapital fracture of the femur. A prospective randomised study. J Bone Joint Surg Br. 1981;63-B:357-361.
   
   
10. Tooke SM, Favero KJ. Femoral neck fractures in skeletally mature patients, fifty years old or less. J Bone Joint Surg Am. 1985;67:1255-1260.