Fractures of the femoral neck: a review and personal statement.

EPIDEMIOLOGY

The number of hip fractures will increase enormously in the decades to come as will the cost of treatment of these patients do. In the USA the annual cost has estimated to be nearly $10 billion. Hip fractures, therefore, represent an enormous socio-economic and medical problem and challenge (orthopaedic) surgeons an anaesthetists to find the cheapest and most effective way to treat them. At the same time the search for preventive measures should be continued. Biphosphonates and hip protectors seem to be able to decrease the risk of suffering a hip fracture with 50%.

CLASSIFICATION

The first classification of femoral neck fractures, proposed by Abraham Colles, in displaced and non-displaced (impacted) fractures appears to be still the most useful one. The Pauwels classification cannot be applied to the preoperative x-ray, because the fractured leg is always in external rotation. The Garden classification is not reproducible and does not lead us to the right treatment.

TREATMENT

Stability and healing chances of impacted fractures depend especially on age and general condition. In patients under 70 years of age without co-morbidity, the secondary instability rate after non-operative treatment is very low: 5%. In elderly people with multiple co-morbidity secondary instability can go up to 80%. These patients are better served with primary operative treatment. Although the majority of surgeons feel good with a strategy of prophylactic internal fixation in all patients, this author pleads for non-operative (early mobilization) treatment of all patients, who are healthy or have only one serious comorbidity. There is consensus about the treatment of displaced fractures in patients under 65 years of age: closed reduction and internal fixation. The best treatment for patients over 80 years of age is prosthetic replacement. In the (large) group of patients between 65 and 80 years of age calendar age is not a reliable guide to the right treatment. There is a growing conviction that the choice between internal fixation and prosthetic replacement in these patients should be made on the basis of the biological age (ASA-score, habitat, the activity level, the need for walking aids and cognitive function). Bone density does not seem to play an important role. If internal fixation is the preferred treatment, the choice of implant is controversial. It is the author's experience that fractures with a steep fracture line (Pauwels 3) should be anatomically reduced and stabilized with a sliding hip screw. The less steep fractures (Pauwels 1 and 2) can be slightly over-reduced in valgus and anteversion, which provides a bony support against shearing forces, and fixed with parallel screws according to the 3-point-fixation principle. The timing of surgery continues to be a controversial subject. From a recent study in our own institution we concluded that no significant association could be found between delay to surgery and the clinical outcomes.However, considering the trends towards less complications and shorter length of hospital stay, early surgery (within 1 day from admission) is likely to be beneficial for hip fracture patients who are able to undergo operation. There is agreement about the use of the cemented arthroplasty. If a hemiarthroplasty is chosen, the bipolar type is to be preferred to the unipolar type. The difference in price between both prostheses is negligible because the overall cost of the treatment have gone up so immensely. Furthermore, a basic advantage of the bipolar system is the relatively small operation, needed for conversion to a total hip replacement, because the stem can stay in place. As to the question hemiarthroplasty or total hip replacement, the discussion has not yet been closed. We studied the natural history of the cemented bipolar hemiarthroplasty by evaluating 307 patients, operated between 1975 and 1989 in our institution. Only 3 patients, who not have been revised, were alive at the end of the observation period (2004). A striking difference was found in the occurrence of late mechanical complications (aseptic loosening and acetabular wear) between patients under 75 years of age (22%) and the older group of patients (6%). As to the patient's overall satisfaction 56% suffered no impairment from their sustained fracture, 36% were slightly impaired. We concluded that the use of the cemented bipolar prosthesis is justified in patients over 75 years of age. Patients between 65 and 75 years of age should either be treated with internal fixation or with a total hip replacement. NONUNION OF THE FEMORAL NECK: Nowadays in cases of nonunions of the femoral neck the surgeon is tempted to perform prosthetic replacement of the hip, the more so if there is also evidence of a disturbed vascularisation of the head. This will provide rapid pain relief and mobilization. However, long-term results of hip arthroplasties, especially in younger people and in presence of bone atrophy, are not always as expected and a less radical approach is worth considering. The intertrochanteric valgization osteotomy, described by Pauwels is an excellent alternative for patients up to 65 years of age with a non-union of the femoral neck. A union rate of 80-90% is described by most authors. Leg length, rotational and angular deformities can be corrected at the same time. Between 65 and 80 years a total hip replacement is probably the best option for fit patients. For elderly patients a cemented bipolar hemiarthroplasty is an adequate treatment.