Introduction                       

Hip fractures in the elderly are associated with impaired mobility, excess morbidity and mortality, and loss of independence. With the trend towards increased longevity and the high prevalence of osteoporosis in this population, hip fractures remain a significant public health concern. Worldwide, 1.6 million new hip fractures occurred in 2000, and these accounted for the loss of 2.35 million disability adjusted life years annually.1 The incidence of hip fractures is estimated to rise to more than six million in 2050, around half of which will be femoral neck fractures.2

 

Hip Arthroplasty in Proximal Femoral Fracture

 

Intracapsular                   Fractures                  

The popular hip fracture classification systems of Garden,3,4 Pauwels5 and the AO group6 have been shown to display a high degree of intra- and inter-observer variability and have limited value in predicting complications associated with fracture healing. A simple radiological classification of either displaced or undisplaced fractures is therefore preferable.

 

UNDISPLACED FRACTURES

This term encompasses those fractures that are truly undisplaced and valgus impacted fractures. Conservative treatment has been described but recent studies have shown that there is an unacceptable rate of displacement (50%).7 Internal fixation with either cannulated screws or a sliding hip screw reduces this risk to 5%, thereby making this the preferred method of treatment.8 Arthroplasty can also be used to treat such fractures but is associated with a significant increase in mortality and complications when compared to internal fixation.9

 

DISPLACED FRACTURES

Operative treatment is recommended in this group using either reduction and internal fixation or replacement arthroplasty. Each patient should be assessed on an individual basis to determine the risks and merits of the different methods of treatment. The decision making process may be influenced by several factors:

 

Age

Nonunion is uncommon in those aged less than 50 years but rises to around 40% for patients over 70 years. Ideally in patients less than 60 years of age the femoral head should be

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preserved as rate of union is higher and thereby avoids complications specific to prosthetic replacement such as dislocation, loosening, wear, or breakage.10,11 Avascular necrosis of the femoral head (AVN) however is more common in younger patients.

 

Sex

Complications from fracture healing in females are twice that in males.10,11

 

Pathological Fractures

Pathological fractures are best treated with cemented arthroplasty.

 

Osteoarthritis and Rheumatoid Arthritis

Arthroplasty is the preferred option if either is present in the hip fracture patient.

 

Delayed Surgery

Irreversible ischemic damage may occur in displaced intracapsular fractures due to distortion and compression of the vascular supply. Some studies have shown that the incidence of AVN is reduced if fractures are reduced and fixed within 6 hours.12 Other studies have shown that a delay of 2 days was not associated with increase in the incidence of AVN.13 Arthroplasty may therefore be a more appropriate treatment if there has been a significant delay from time of injury to surgery.

 

Total Hip Arthroplasty

 

Internal Fixation vs Arthroplasty and Cost Analysis      

Reduction and fixation of a displaced femoral-neck fracture can be a technically demanding surgical procedure. It allows the patient to retain his/her own femoral head, and thereby avoid problems specific to prosthetic replacement. Rates of implant failure, displacement, and reoperation for internal fixation have been reported in the literature.14 A meta-analysis of 13 studies in the Cochrane database concluded that internal fixation was associated with less operative trauma than replacement (decreased operative time, blood loss, transfusion, and infection) but a higher need for reoperation.15

A more recent randomized control trial by Parker et al concluded that both internal fixation and arthroplasty produce similar final outcomes of treatment. Internal fixation may have a slight tendency towards improved mobility in comparison to an uncemented arthroplasty but fixation incurs a markedly increased reoperation rate (30 to 50% vs. 6 to 18%).16 Several authors have described cost-effectiveness analyses of various methods of treatment.17-20 Iorio et al,18 presented a cost-effectiveness analysis of four surgical treatments for a displaced femoral neck fracture, considering initial hospital costs, rehabilitation costs, and costs of reoperations and complications. The authors concluded that cemented THA

was the most cost-effective treatment and that internal fixation was the most expensive.

Other investigators have drawn similar conclusions despite using different methodolo-gies.17 Further long-term results may confirm the findings that the more expensive initial treatment may prove cost-effective in this osteoporotic group of hip fractures.

 

Extracapsular Fractures

 

Intertrochanteric femur fractures in the elderly are typically the result of low-energy trauma. However, due to poor bone quality the fractures produced can often be comminuted. These fractures are broadly classified as stable versus unstable. Fractures are termed stable when there is no comminution of the calcar region and lesser trochanter ensuring good cortical contact between the fracture fragments medially. Patients with stable fractures can be successfully treated with internal fixation devices. Indications for hip arthroplasty include

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Hip Arthroplasty in Proximal Femoral Fracture

 

Figures 30.1A to C: (A and B) Preoperative X-rays showing nonunion 18 months following internal fixation of proximal femur fracture

(C) Postoperative X-ray showing removal of implant and conversion to total hip arthroplasty

 

patients in which internal fixation has failed either with femoral head penetration or cut out of the screw (Figs 30.1A to C), comminuted fractures where internal fixation is unlikely to succeed, certain pathological fractures and fractures with pre-existing arthritis affecting the hip.

 

Hemiarthroplasty vs Total Hip Arthroplasty

 

There are different options with regard to the type of arthroplasty to be performed for femoral neck fracture. Hemiarthroplasty can be performed with either a modular unipolar or bipolar endoprosthesis. The bipolar design was developed to reduce metal on cartilage motion and friction, and thereby decrease acetabular wear and erosion, a postulated cause of postoperative pain. Several studies have shown good results for bipolar endoprostheses, particularly when they were cemented.21-23 However, other studies have demonstrated that a bipolar hemiarthroplasty functions as a unipolar device within three to twelve months after surgery.24,25

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Total Hip Arthroplasty

 

Figures 30.2A and B: (A) X-ray pelvis showing a displaced left intracapsular fracture neck of femur in a fit 65-year-old patient, (B) Postoperative check X-ray following treatment with total hip arthroplasty

 

Total hip replacement (Figs 30.2A and B) is indicated in younger fit patients with delayed presentation, patients with acetabular damage, pre-existing osteoarthritis or rheumatoid arthritis and in the management of failed internal fixation.

Hopley et al in a meta-analysis of data from fifteen studies including 1890 arthroplasty procedures showed a lower risk of reoperation after total hip arthroplasty compared with hemiarthroplasty.26 Furthermore, total hip arthroplasty showed better hip function after one to four years. No significant difference was seen for the risk of dislocation and other general complications.

In contrast, a recent multicentre randomized control trial from the Netherlands suggested that after one and five years follow up the results of bipolar hemiarthroplasty were similar to THR for the treatment of patients aged >70 years, with displaced femoral fractures.27 The higher intraoperative blood loss, increased duration of surgery, higher incidence of dislocation, and greater costs discouraged the authors from recommending THR in patients with a displaced fracture of the femoral neck. The functional results were similar in the two groups, and showed no differences in mortality and revision rates. A Cochrane review produced similar findings.28

 

Use        of        Polymethylmethacrylate               

Although to some extent an old debate, this issue has attracted renewed interest of late because of the risk of the potentially catastrophic bone-cement implantation syndrome. Bone-cement implantation syndrome is associated with substantial mortality and morbidity. The syndrome is characterised by hypoxia, hypotension or both and/or unexpected loss of consciousness occurring around the time of cementation, prosthesis insertion or reduction of the joint.29 Two main mechanisms have been proposed. The more robust theory is that of emboli being dislodged into the pulmonary vasculature because of high intramedullary pressures and raised temperatures developing during prosthesis insertion and cementation.30 A less favored theory is that of cement monomer entering the circulation during cementation and inducing pulmonary or cardiovascular effects. The use of vacuum mixing in third generation technique has reduced the concentration of free monomer present in the cement introduced.

Data from national joint registries indicate that cemented total hip replacements remain the gold standard and surgeons in Europe tend to favor cemented total hip replacements

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although numbers of uncemented components are ever increasing. American and Canadian surgeons tend to favor the use of uncemented total hip replacements. For hemiarthroplasties, Swedish and Australian surgeons favor the use of cemented implants.

Hip Arthroplasty in Proximal Femoral Fracture

 

Analysis of the Research and Learning System database at the National Patient Safety Agency in the United Kingdom revealed that 96% (24/25) of the reported deaths in patients undergoing total hip replacement or arthroplasty occurred in patients having cemented procedures, while only 4% (1/25) of deaths occurred in those receiving an uncemented prosthesis.31 Whilst these figures appear startling, interpretation of these results should be carried out with care. Underreporting of events to these databases, inevitable selection biases, and the large potential for significant confounding factors, such as fracture severity and patient co-morbidities could all skew the results. The 2007 UK National Joint Registry has highlighted a higher mortality in patients undergoing cemented total hip arthroplasty as compared with the uncemented group.32 A further study of 29431 patients found 23 intraoperative deaths, all in those having cemented procedures, while no intraoperative deaths occurred in more than 12500 patients who had a noncemented procedure.33 In a review of 7774 patients with hip fractures treated by arthroplasty, the mortality was more than doubled (3.5% versus 1.5%) when cement fixation was used.34 In contrast, a meta-analysis of 2613 hemiarthroplasties found no statistical difference in the mortality of elderly patients with a hip fracture who had a cemented or uncemented procedure.35 Furthermore, an audit of 9082 total hip arthroplasties that used cement identified only one intraoperative death secondary to a fat embolism.36 This is mirrored in a recent Cochrane review that concluded that there is reasonable evidence from randomized studies that cemented prosthesis reduce the amount of residual pain in the hip and also allow better restoration of mobility. There is no evidence of any significant adverse effects of cement on mortality or other complications encountered apart from the very occasional adverse reaction to cement during surgery.37

Given the potential for complications using cement, uncemented femoral components have some appealing features in the hip fracture population. These include speed of implantation and probable lower risk of fat and marrow embolism compared to cemented implants. The results of routine use of modern uncemented femoral components designed for bone ingrowth or ongrowth in the hip fracture patient population with poor bone have been shown to be favorable in limited numbers. Klein and colleagues studied 85 elderly patients with an acute femoral neck fracture treated with THA using a tapered, proximally coated femoral stem.38 At a mean follow up of 3.8 years, all femoral components were stable with evidence of bone ingrowth in all but one hip, which was felt to have stable fibrous ingrowth. Mild thigh pain was present in 3 patients.

According to the UK and Swedish joint registers, uncemented primary implants have higher revision rates. It would follow therefore that long-term implant stability along with the rates of femur fracture and pain relief in the hip fracture population require further study.31

 

Indications                        

Nondisplaced or impacted fractures are better treated with fixation in situ using cannulated screws or a dynamic hip screw. As previously mentioned, patients with displaced intracapsular fractures should be assessed on an individual basis to determine the best method of treatment. As a general rule Hemiarthroplasty is indicated for displaced femoral neck fractures in physiologically older adult patients (some have suggested approximately 70 years of age), or in younger patients with limited life span due to systemic disease, impaired ability to heal fractures, or irreparably damaged femoral heads. Fractures in younger patients (chronologically or physiologically) or in those with pre-existing arthritic changes or insufficient acetabular structure should be treated with total hip arthroplasty.

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Preoperative                   Planning                   

This starts as always with a thorough history and physical examination. The exact circumstances surrounding the fall are elicited, seeking to exclude any medical condition that would require further investigation and possible referral. A full social history should also be taken. The injured leg is typically shortened, externally rotated and painful with movement. The examination should be thorough and include an evaluation for other associated insufficiency fractures, such as the distal radius, pelvis, or spine and for possible fall associated traumatic conditions such as subdural hematoma. At our institution all elderly patients admitted with a fracture neck of femur are routinely evaluated by an orthogeriatrician. Such patients often have multiple complex medical comorbidities and can be a challenge to medically optimize prior to surgery. If patients are reported to have had multiple falls in the past then a falls assessment is carried out prior to discharge. The aim is to evaluate and manage any treatable causes and thus prevent further falls in the future.

Laboratory studies include a full blood count, serum electrolytes, a blood sample for group and save, chest radiograph, and electrocardiogram. Other hematological studies may be necessary depending on patient’s medical condition. Adequate anteroposterior (AP) and lateral radiographs of the hip and proximal femur are necessary to confirm diagnosis and plan management.

Sizing templates for the prosthetic system are used to estimate the size of the prosthesis and measure the level of the neck cut on the uninjured hip. If a THR is to be used it also estimates the size and position of the acetabular component.

 

Total Hip Arthroplasty

 

Surgery                         

The procedure may be performed under general or spinal anesthesia. Regional techniques may offer less risk of some anesthetic complications, but several large retrospective, nonrandomized studies of hip fracture surgery have failed to show any difference in mortality, morbidity, or functional outcome.39-42

Preoperative intravenous antibiotics are given in accordance with local microbiology guidelines.

The two most common surgical approaches used in patients undergoing elective THA are the lateral or posterior approach. The ‘approach of choice’ in a hip fracture patient has been proposed to be the lateral approach to the hip. In the hip fracture population this has the theoretical advantage of leaving the posterior capsule intact thus reducing the propensity for posterior dislocation. The trade-off appears to be a slightly higher incidence of damage to the abductor muscle mass and associated limp.

Hardinge originally described a lateral incision centred over the greater trochanter and parallel to the femoral shaft.43 If this approach is to be used it must be remembered that the superior gluteal nerve is at risk in the proximal extent of the wound. It passes 4.5 cm above and 2 cm behind the tip of the greater trochanter and some authors recommend only detaching and splitting the anterior third of the gluteus medius to avoid damage to this structure.

Keene and Parker, in their study on the posterior and Hardinge approach, found no difference in length of hospital stay, dislocation rate or the rate of mortality with either approach.44 They recommended that the approach used should be the one with which the operating surgeon was most comfortable.

Postoperative dislocations were found more often in patients where the posterior approach had been used and in patients with preoperative flexion adduction contractures of the hip.45 In such patients use of the lateral approach was recommended.

Dislocations in the context of either approach may be due to incorrect offset of the implant. Use of modular implants allows a choice of offset and neck length while permitting the use of

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Hip Arthroplasty in Proximal Femoral Fracture

 

a large modular femoral head. These characteristics combine to ensure a highly functional yet stable hip prosthesis.

 

Postoperative                 Management                

Chemical prophylaxis against deep venous thrombosis (DVT) is commenced either on admission or the evening of surgery. Mechanical devices such as foot or calf pumps may also be used and patients are measured and fitted for TED® stockings (Kendall Healthcare products) on admission. Antibiotics are administered for 24 hours after surgery. Repeat blood tests and an X-ray to check implant position are performed soon after surgery. The patient is allowed to mobilize full weight bearing as soon as is able and taught appropriate transfer techniques. Physiotherapists, Occupational therapists and social workers can help assess the patient’s abilities and needs for placement decisions.

 

Complications                      

The early mortality rate (less than 3 months) for patients after hemiarthroplasty for femoral neck fracture has been reported from 5 to 23%.46,47 Patient mortality at 1 year is between 17 and 34%.15,46,48-52 Mortality does not differ between patients undergoing total hip arthroplasty and hemiarthroplasty.26 Due to the elderly nature of the patient population, mortality increases over time.

Medical complications are common in the postoperative period, including urinary and respiratory tract infections, DVT and pulmonary embolism, cardiac failure, arrhythmia or infarction, stroke, gastrointestinal bleeding, and renal failure. A prospective outcome study of 270 patients revealed a 16% rate of major medical complication and a 35% rate of minor medical complication.50

Dislocation rates may be higher in patients undergoing total hip arthroplasty rather than hemiarthroplasty,15,46,53 but this is not a universal finding.26 Deep infection has been reported to occur in 0 to 18% of patients. The pooled relative risk of infection after total hip arthroplasty compared with hemiarthroplasty is 1.27.26 Overall, primary total hip arthroplasty was associated with a lower risk of subsequent reoperation compared with hemiarthroplasty.26

 

Summary and Our Management of Patient with Fracture Neck of Femur

 

In this chapter, an overview of the literature and current evidence in the management of patient with fracture neck of femur has been presented. Our management of the patient presenting with fracture neck of femur depends on the type and degree of displacement of the fracture, the age, and preoperative mobility status of the patient. Patients with extracapsular fractures are generally managed with closed or open reduction and internal fixation either with a dynamic hip screw or a cephalomedullary nail. Hip arthroplasty is considered only in patients with failure of fixation or nonunion of the fracture where further fixation is not appropriate.

Young patients with an intracapsular fracture neck of femur are managed with internal fixation in situ when the fracture is undisplaced or after reduction in displaced fractures. Patients over 75 years are treated with screw fixation of undisplaced fractures or hemiarthroplasty of displaced subcapital fracture neck of femur.

The optimum management of the physiologically fit and active patient in the 60 to 75 years with a displaced subcapital fracture neck of femur is the subject of much of the debate in this chapter. Treatment is individualized and the patient must be counseled about the pros and cons of internal fixation versus an arthroplasty.

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   Total Hip Arthroplasty

    

3. Garden RS. Stability and union in subcapital fractures of the femur. J Bone Joint Surg [Br] 1964;46-B:630-47.

4. Frandsen P, Anderson E, Madsen F, Skjot T. Garden’s classification of femoral neck fractures. An Assessment of interobserver variation. J Bone Joint Surg [Br] 1988;70-B:588-90.

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26. Hopley C, Stengel D, Ekkernkamp A, Wich M. Primary total hip arthroplasty versus hemiarthroplasty for displaced intracapsular hip fractures in older patients: systematic review. BMJ 2010;340:c2332.

    Hip Arthroplasty in Proximal Femoral Fracture

     

27. Van denBekerom MPJ, Hilverdink, EF, Sierevelt IN, Reuling EMBP, Schnater JM, Bonke H, et al. A comparison of hemiarthroplasty with total hip replacement for displaced intracapsular fracture of the femoral neck: a randomized controlled multicenter trial in patients aged 70 years and over. J Bone Joint Surg [Br] 2010;92-B:1422-8.

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43. Hardinge K. The direct lateral approach to the hip. J Bone Joint Surg Br. 1982;64(1):17-9.

44. Keene GS, Parker MJ. Hemiarthroplasty of the hip—the anterior or posterior approach? A comparison of surgical approaches. Injury 1993;24(9):611-3.

45. Anderson LD, Hamsa WR Jr, Waring TL. Femoral prosthesis. A review of three hundred and fifty six operations and their results. J Bone Joint Surg Am 1964;46:1049-65.

46. Bhandari M, Devereaux PJ, Swiontkowski MF, et al. Internal fixation compared with arthroplasty for displaced fractures of the femoral neck: a meta-analysis. J Bone Joint Surg Am 2003;85(9): 1673-81.

47. Lennox IAC, McLauchlan J. Comparing the mortality and morbidity of cemented and uncemented hemiarthroplasties. Injury 1993;24(3):185-6.

48. Calder SJ, Anderson GH, Jagger C, et al. Unipolar or bipolar prosthesis for displaced intracapsular hip fracture in octogenarians: a randomized prospective study. J Bone Joint Surg Br 1996;78(3): 391-4.