A comparison of hemiarthroplasty with total hip replacement for displaced intracapsular fracture of the femoral neck

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1 A comparison of hemiarthroplasty with total hip replacement for displaced intracapsular fracture of the femoral neck A RANDOMISED CONTROLLED MULTICENTRE TRIAL IN PATIENTS AGED 70 YEARS AND OVER M. P. J. van den Bekerom, E. F. Hilverdink, I. N. Sierevelt, E. M. B. P. Reuling, J. M. Schnater, H. Bonke, J. C. Goslings, C. N. van Dijk, E. L. F. B. Raaymakers From Academic Medical Center, Amsterdam, the Netherlands M. P. J. van den Bekerom, MD, Resident E. F. Hilverdink, MSc, Medical Student I. N. Sierevelt, MSc, Researcher C. N. van Dijk, MD, PhD, Professor E. L. F. B. Raaymakers, MD, PhD, Orthopaedic Surgeon (Retired) Department of Orthopaedic Surgery E. M. B. P. Reuling, MD, Resident J. C. Goslings, MD, PhD, Professor Department of Trauma Surgery Academic Medical Center, P. O. Box 22660, 1105 AZ Amsterdam, The Netherlands. J. M. Schnater, MD, PhD, Surgeon Department of General Surgery Albert Schweitzer Hospital, P. O. Box 333, 3300 Dordrecht, The Netherlands. H. Bonke, MD, Orthopaedic Surgeon Department of Orthopaedic Surgery Tergooi Hospitals, P. O. Box 10016, 1201 DA Hilversum, Blaricum, The Netherlands. Correspondence should be sent to Dr E. L. F. B. Raaymakers; e- mail: fam.raaymakers@planet.nl 2010 British Editorial Society of Bone and Joint Surgery doi: / x.92b $2.00 J Bone Joint Surg [Br] 2010;92-B: Received 19 March 2010; Accepted after revision 10 June 2010 The aim of this study was to analyse the functional outcome after a displaced intracapsular fracture of the femoral neck in active patients aged over 70 years without osteoarthritis or rheumatoid arthritis of the hip, randomised to receive either a hemiarthroplasty or a total hip replacement (THR). We studied 252 patients of whom 47 (19%) were men, with a mean age of 81.1 years (70.2 to 95.6). They were randomly allocated to be treated with either a cemented hemiarthroplasty (137 patients) or cemented THR (115 patients). At one- and fiveyear follow-up no differences were observed in the modified Harris hip score, revision rate of the prosthesis, local and general complications, or mortality. The intra-operative blood loss was lower in the hemiarthroplasty group (7% > 500 ml) than in the THR group (26% > 500 ml) and the duration of surgery was longer in the THR group (28% > 1.5 hours versus 12% > 1.5 hours). There were no dislocations of any bipolar hemiarthroplasty and eight dislocations of a THR during follow-up. Because of a higher intra-operative blood loss (p < 0.001), an increased duration of the operation (p < 0.001) and a higher number of early and late dislocations (p = 0.002), we do not recommend THR as the treatment of choice in patients aged 70 years with a fracture of the femoral neck in the absence of advanced radiological osteoarthritis or rheumatoid arthritis of the hip. Each year more than five million people in the world sustain a hip fracture producing the loss of at least 2.34 million disability-adjusted years of life. 1,2 Whether fractures of the femoral neck in elderly patients should be treated with internal fixation, hemiarthroplasty, or total hip replacement (THR) should be determined by the degree of fracture displacement, the patient s age, functional demands and risk profile such as level of cognitive function and degree of physical fitness. 3-6 Internal fixation is recommended as the treatment of choice in young patients with displaced intracapsular fractures 5 and in very elderly patients, not medically fit for prosthetic surgery. 7 There appears to be a consensus among orthopaedic surgeons that unipolar or bipolar hemiarthroplasty is the preferred treatment for displaced intracapsular fractures in elderly patients with low functional demands, 8 however, for the relatively healthy, active and mentally alert elderly patient, treatment is still controversial. 8,9 Nevertheless, most orthopaedic surgeons prefer hemiarthroplasty over THR in the management of patients with this injury. 8 Two studies 10,11 evaluated the optimal type of arthroplasty in a properly designed randomised controlled trial at the time that this study was initiated. The conclusion of a meta-analysis of these studies 6 was that there was insufficient evidence to indicate a preference between different types of arthroplasty. In contrast to this, three recent randomised studies and a meta-analysis concluded that THR provides better function than hemiarthroplasty. 6,12-14 However, these conclusions were based on relatively small study populations and short follow-up. Therefore, the best treatment of mobile, independent patients who have sustained a displaced fracture of the femoral neck remains controversial. The aim of this study was to analyse the functional outcome of displaced femoral neck fractures in patients, who were physically and mentally healthy, and randomised to receive either a bipolar hemiarthroplasty or a THR. Functional outcome was the primary endpoint and revision rates, mortality and complication rates were secondary outcomes. Our hypothesis was that the late functional results of patients with a THR would be superior to patients with a bipolar hemiarthroplasty. Patients and Methods This trial s continuity and scientific development were supervised by the A Randomised 1422 THE JOURNAL OF BONE AND JOINT SURGERY

2 A COMPARISON OF HEMIARTHROPLASTY WITH THR FOR DISPLACED INTRACAPSULAR FRACTURE OF THE FEMORAL NECK 1423 Trial: Hemi-arthroplasty versus total hip Replacement Outcome (ARTHRO) trial group. The trial was an open, multicentre, randomised design to compare two policies for the surgical management of displaced fractures of the femoral neck in patients 70. This design also recognised that an alternative operation might be indicated later because the initially allocated procedure would have failed. Patients, surgeons and outcome assessors were not blinded. The study was conducted in seven district hospitals and one university hospital. An unpublished interim analysis was performed in 1997 and the ARTHRO trial group found no grounds for stopping or altering the trial, either on the basis of data presented and the observed comparisons between groups or from information about other trials being conducted at that time. All patients with a displaced fracture of the femoral neck who were admitted to the participating hospitals were considered for trial entry. Inclusion criteria were: displaced intracapsular femoral neck fracture, capability to give informed consent, no known metastatic disease, no contraindication to anaesthesia, age 70 years, and the ability to understand written Dutch. The exclusion criteria were: inability to fulfil the inclusion criteria including refusal to consent, advanced radiological osteoarthritis or rheumatoid arthritis in the fractured hip; suspected pathological fracture; patients who were bedridden or barely mobile bed to chair; significant senile dementia. Randomisation. Eligible patients were allocated to one of the two treatment groups by a computer randomisation program. The randomisation centre held the following information: patient initials, gender, date of birth and the side of the fractured hip, in whom the inclusion and exclusion criteria had been confirmed. The investigator was immediately informed of the assigned treatment modality produced by the computer randomisation program, and was provided with the trial number to be entered on the case report forms. Confirmation was made by fax. 15 Sample size. The smallest difference in the Harris hip score (HHS) considered clinically important was ten points. The mean HHS in our patient population was expected to be 70 points and the SD estimated to be a maximum of 20 points. With an alpha level of 0.05 and a power of 90%, 83 patients would be needed in each group. However, it was necessary to account for an expected five-year mortality in the study group (mean age 80 years) of approximately 60%. Therefore the numbers needed were increased by a factor of 2.5, resulting in a total number of 200 patients needed per study group. An interim analysis of the mortality identified this to be only 41% in our selected patient group and accordingly the sample size was reduced to 140 patients per group. All operations were performed by experienced surgeons or residents under the direct supervision of an experienced surgeon. Patients received either a hemiarthroplasty or a THR where one of two types of cemented femoral prostheses were implanted, a Weber Rotationsprosthese (Sulzer AG, Winterthur, Switzerland) or a Müller Geradschaftprothese (Protek AG, Münsingen, Switzerland), either as a hemiarthroplasty or a THR. The femoral components of the former were available in 2 mm increments. Surgeons were advised to use a 32 mm diameter modular head when performing a THR. Participating surgeons were allowed to use their own judgement to manage care in other respects such as antibiotic and thromboembolic prophylaxis and surgical approach to the hip. The surgical approaches used were either anterolateral, straight lateral or posterolateral. The wound dressings also followed local guidelines. Patients in both groups were mobilised bearing full weight as tolerated with the aid of crutches, they were allowed to sit on a high chair immediately after surgery and to abandon crutches at their convenience. Our standard post-operative protocol for the prevention of dislocation included the use of patient education and physiotherapy supervision in activities of daily living. After six weeks patients were allowed to mobilise without further restriction. The peri-operative characteristics are summarised in Table I. Primary assessment and follow up Case report documentation was completed upon admission, after the operation, upon discharge and at the oneand five-year follow-up visits to the outpatient clinic. Data collection was performed by the local researcher. At the one- and five-year visits, the patients were assessed using a modified HHS 15 as the primary outcome measure. The modification of the HHS was the omission of the physical examination score. A correction of summed residual scores was applied to allow for a maximum score of 100. This modification had been used previously. 16,17 Secondary outcome measures were mortality, revision operations, and general and implant-related complications during follow-up. A complication in our study was defined as an unintended and undesirable event or condition following operation that was harmful for the patient and necessitated adjustment of medical treatment, or led to permanent harm. Implant-related complications were confined to the area of the hip and were due to prosthetic implantation or the surgical approach. A radiograph of the pelvis and an axial hip view were obtained at each visit for comparison. Final radiographs were analysed for subsidence of the stem and acetabular component migration, polyethylene wear, osteoarthritis of the acetabulum, protrusio acetabuli, fractures and fissures, and heterotopic ossification. Patients who were unable or unwilling to attend as outpatients were visited in their home or interviewed by telephone. Telephone reviews were supplemented with information from health personnel, general practitioners or family members. If a patient had died since the previous annual follow-up, the same personnel were interviewed. Statistical analysis. Two investigators (MPJB, EMBPR) entered all data in a SPSS database v (SPSS Inc., Chicago, Illinois) which was checked for accuracy by two VOL. 92-B, No. 10, OCTOBER 2010

3 1424 M. P. J. VAN DEN BEKEROM, E. F. HILVERDINK, I. N. SIEREVELT, ET AL 281 patients entered the ARTHRO trial 29 patients were secondarily excluded other type of prosthesis (11) patients had dementia (6) patients were bedridden (4) had no fracture (1) had another type of fracture (2) data entered double in database (2) < 70 years old (1) no operation was performed (1) refused participation after randomisation (1) Available 252 patients 137 received hemiarthroplasty 115 received total hip replacement 1-year follow-up Mortality (18) Available (119) 1-year follow-up Mortality (16) Available (99) 5-year follow-up Mortality (61) Available (76) 5-year follow-up Mortality (71) Available (44) Fig. 1 Flow chart of the patients recruited. other investigators (EFH, INS), for subsequent statistical analysis. Mean HHS as well as other parameters were tested for statistical significance depending on their distribution either by a Student s t-test or a Mann-Whitney U test. Dichotomous variables, such as rates of revision and displacement were analysed using a chi-squared test or Fisher s exact test as appropriate. These were performed two-sided with a p-value < 0.05 considered statistically significant. The data were subjected to a per protocol analysis. Ethical approval. The study was conducted in accordance with the Helsinki declaration, as amended in Tokyo and Venice, 18 and in accordance with the laws and regulations of the Netherlands. All patients gave their informed consent to participate and the protocol was approved by the Institutional Review Board (Medical Ethics Committee) of the participating institutions. Results A total of 281 patients were randomised (Fig. 1), but 29 did not match the inclusion criteria or did not receive the prosthesis for which they had been randomised and were excluded. Protocol violations occurred in 11 patients with fixation of a hip screw or hemiarthroplasty instead of THR or the reverse, six patients with dementia (four patients who were bedridden, two patients with an intertrochanteric fracture, two patients who had their data entered twice, one patient who did not have fracture, one patient was aged only 69 years, one patient who did not receive an operation and one patient who refused to participate after randomisation. After validation 252 patients were included in the study and their data was available for analysis (Fig. 1), 137 were randomised for a bipolar hemiarthroplasty and 115 patients for a THR. Their mean age was 81.1 years (70.2 to 95.6). Of the 252 patients, 47 (19%) were male and 205 (81%) were female. The side of the fracture was evenly distributed between the two groups, with 100 on the right and 152 on the left. Baseline data are shown in Table I. Intra-operative data are shown in Table II. One patient who was admitted died on the second post-operative day. The one-year outcome measures are shown in Table III. The mean modified HHS was 73.9 (23 to 100) in the bipolar hemiarthroplasty group and 76.0 (44 to 100) in the THR group. This difference was not significant (p = 0.40). At five years follow-up (Table IV) the mean modified HHS THE JOURNAL OF BONE AND JOINT SURGERY

4 A COMPARISON OF HEMIARTHROPLASTY WITH THR FOR DISPLACED INTRACAPSULAR FRACTURE OF THE FEMORAL NECK 1425 Table I. Baseline data of all patients HA * (n = 137) THR (n = 115) Mean age in years (range) 80.3 (70.2 to 93.9) 82.1 (70.1 to 95.6) Gender (%) Male:female 22 (16)/115 (84) 25 (22)/90 (78) Fracture side (%) Left:right 78 (57)/59 (43) 74 (64)/41 (36) ASA score (%) I 19 (14) 11 (10) II 77 (57) 48 (42) III 33 (24) 44 (38) IV 5 (4) 10 (9) V 0 (0) 0 (0) Unknown 3 (2) 2 (2) Comorbidities (%) Cardiovascular 34 (25) 38 (33) Malignancies 11 (8) 6 (5) Pulmonary 16 (12) 18 (16) Neurological 26 (19) 33 (29) Locomotive 22 (16) 31 (27) Diabetes 19 (14) 11 (10) Analgesics (never) 97 (71) 71 (62) Mobility without a stick 85 (62) 64 (56) Climbing stairs (normal or with use of rail) 91 (66) 77 (67) * HA, hemiarthroplasty THR, total hip replacement ASA, American Society of Anaesthesiologists 36 was 71.9 (33 to 99) in the bipolar hemiarthroplasty group and 75.2 (45 to 96) in the THR group. This difference was still not significant (p = 0.22). Complications. In the bipolar hemiarthroplasty group 34 patients (25%) had one or more complications. In the THR group 28 patients (24%) had one or more complications. This was not a statistically significant difference (p = 0.93). Of the 81 general complications 25 were cardiovascular, 24 neurological, six urological, five respiratory, two gastrointestinal, and there were 19 other general complications such as pressure ulcer, allergic reaction due to medication, kidney failure due to medication or operation. There were 15 (11%) local in-hospital complications observed in the bipolar hemiarthroplasty group and 17 (15%) in the THR group. This was not a statistically significant difference (p = 0.36). These 32 local complications consisted of 19 extensive haematomas, five dislocations of a THR, three superficial infections, two deep infections, two wound dehiscences and one superior gluteal palsy. At final follow-up there were no dislocations in the hemiarthroplasty group (p = 0.002) and eight dislocations in the THR group. Three of 225 patients with an anterolateral approach had a dislocation and five of the 27 patients with a posterolateral approach had a dislocation, this difference was statistically significant (p = 0.007, Fisher exact). At the five-year follow-up six patients (4%) in the bipolar hemiarthroplasty group and two patients (2%) in the THR group had undergone a revision operation. This was not a significant difference (p = 0.29). There were five revisions for loosening of the arthroplasty, two for osteoarthritis of the acetabulum and one for a low grade deep infection. At one year follow-up 18 patients (13%) in the bipolar hemiarthroplasty group died compared with 16 patients (14%) in the THR group. This was not statistically significant (p = 0.86). At the five-year follow-up 61 patients (44%) in the bipolar hemiarthroplasty group died, compared with 71 patients (62%) in the THR group. This was not a significant difference (p = 0.09). Radiographs were assessed annually. The only patient who developed protrusion of the acetabular component of a THR did not require a revision because they were asymptomatic. Four patients with osteoarthritis of the acetabulum also showed radiographic loosening of the stem of the bipolar hemiarthroplasty. Discussion As the elderly population increases the occurrence of a femoral neck fracture is becoming more common giving these fractures increasing socioeconomic importance. 1,2 Successful management is vital for both the individual patient and VOL. 92-B, No. 10, OCTOBER 2010

5 1426 M. P. J. VAN DEN BEKEROM, E. F. HILVERDINK, I. N. SIEREVELT, ET AL Table II. Operative details of all patients HA * (n = 137) THR (n = 115) Mean interval trauma to surgery in days (range) 1.0 (0 to 10) 1.0 (0 to 9) Surgeon (consultant/resident) (%) 27 (25)/82 (75) 51 (57)/38 (43) Approach (%) Posterolateral 5 (4) 22 (19) Anterolateral 132 (96) 93 (81) Anaesthesia (%) Spinal 92 (67) 71 (62) Epidural 5 (4) 11 (10) Complete 25 (18) 30 (26) Psoas block 2 (1) 0 (0) Unknown 13 (9) 3 (3) Blood loss (%) p < (chi-squared) < 500 ml 111 (81) 70 (61) > 500 ml 8 (6) 25 (22) Unknown 19 (14) 20 (17) Duration of operation (%) < 1 hour 44 (35) 10 (10) 1 to 1.5 hours 66 (53) 65 (57) > 1.5 hours 15 (12) 30 (20) Unknown 22 (16) 10 (9) Duration of hospital stay (range) 17.1 (2 to 89) 18.4 (4 to 86) Mortality during hospital stay (%) 7 (5) 5 (4) * HA, hemiarthroplasty THR, total hip replacement there were 26 unknown Table III. Outcome measures at one year follow-up HA (N = 137) THR (n = 115) p-value Mean modified HHS (range) * 73.9 (23 to 100) 76.0 (44 to 100) 0.40 Mean HHS pain (range) 37.5 (10 to 44) 40.0 (20 to 44) Mean HHS function (range) 20.7 (0 to 36) 20.8 (0 to 36) Complications (in-hospital) (%) General (patients) 23 (25) 28 (24) 0.93 Local (patients) 15 (11) 17 (15) 0.36 Mortality (%) 18 (13) 16 (14) 0.86 Revision operations 1 0 * the total modified Harris Hip Score (HHS) was converted to a maximum of 100 points HA, hemiarthroplasty THR, total hip replacement mean modified HHS: students t-test; general, local, mortality: chi-squared test future demands on the health service. The goals of any treatment method for fractures of the femoral neck are to return the patient as quickly as possible to a satisfactory functional status with minimal morbidity and mortality, minimising the need for re-operation. Debate about the role of arthroplasty and the comparative benefits of hemiarthroplasty and THR for an acute displaced femoral neck fracture has been ongoing. 19,20 Our findings suggest that after one and five years followup the results of bipolar hemiarthroplasty are similar to THR for the treatment of patients aged 70 years, with displaced femoral fractures. Our findings relate to patients who are in relatively good physical and mental condition and have neither osteoarthritis or rheumatoid arthritis affecting the hip, however, in the presence of these conditions, THR is indicated. 20 The higher intra-operative blood THE JOURNAL OF BONE AND JOINT SURGERY

6 A COMPARISON OF HEMIARTHROPLASTY WITH THR FOR DISPLACED INTRACAPSULAR FRACTURE OF THE FEMORAL NECK 1427 Table IV. Outcome measures at five years follow-up HA (n = 137) THR (n = 115) p-value Mean modified HHS (range) * 71.9 (33 to 99) 75.2 (45 to 96) 0.22 Mean HHS pain (range) 38.6 (10 to 44) 40.1 (20 to 44) Mean HHS function (range) 18.6 (4 to 35) 20.1 (7 to 33) Mortality (%) 61 (44) 71 (54) 0.09 Revision operations (%) 6 (4) 2 (2) 0.29 (Fischer exact) Dislocation of prosthesis (%) 0 8 (7) Radiological findings (%) Loosening of femoral component 5 (4) 1 (1) Loosening of acetabular component Not applicable 0 Polyethylene wear Not applicable 0 Osteoarthritis at the acetabulum 14 (10) Not applicable Protrusio acetabuli 4 (3) 1 (1) Fracture/fissure at the acetabulum 3 (2) 1 (1) Heterotopic ossification 14 (10) 17 (15) * the total modified Harris Hip score (HHS) was converted to a maximum of 100 points HA, hemiarthroplasty THR, total hip replacement mean modified HHS: students t-test; mortality: chi-squared test; revision operations, dislocation of prosthesis: Fisher s exact test. loss, increased duration of surgery, higher incidence of dislocation, and greater costs discourage us 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 of the prosthesis during follow-up. In our opinion four important factors should determine the selection of a THR or hemiarthroplasty: functional outcome of the patients, complications associated with the procedure such as dislocation, acetabular erosion and the costs of the operation. A Cochrane review produced similar findings to our own; 6 THR was associated with a longer operation time but with a tendency to better functional outcome scores compared with hemiarthroplasty. 6 Bhandari et al 8 found in a survey that many orthopaedic surgeons felt that the shortterm outcome following a bipolar hemiarthroplasty was comparable with that after a THR. However, these conclusions are in contrast with the two most recent randomised studies by Blomfeldt et al 13 and Baker et al 14 which concluded that a THR provided better function based on the HHS and Oxford Hip Score. 21 Although our study was based on computer randomisation, a larger sample size and a longer follow-up, we do not believe that these are the reasons for the difference, as the hemiarthroplasty we implanted was bipolar and all prostheses were cemented. Some surgeons prefer to perform a THR to avoid long-term wear of acetabular cartilage and the subsequent need for conversion of the hemiarthroplasty to a THR. 13 After five years follow-up we observed obvious acetabular erosion in 10% of the patients with the former. Only two patients required a revision operation to a THR because of complaints caused by this acetabular erosion. Although we performed a bipolar hemiarthroplasty, reports have shown that a bipolar hemiarthroplasty functions as a unipolar device within three to 12 months after surgery. 22,23 The hemiarthroplasties we used had bipolar heads available in 2 mm increments, more acetabular erosion is observed when surgeons use a unipolar hemiarthroplasty which only allows sizing increments of 3.2 mm. 24 We suspect the ability to match precisely the acetabular dimensions, while desirable, is less important than the activity level of the patient, and that our relatively younger and more active patients had a higher rate of acetabular erosion because of increased physical demands. 14,24-26 After five years follow-up we observed no dislocations in the bipolar hemiarthroplasty group and eight dislocations in the THR group. In one patient malpositioning of the stem and acetabular component was present, in the other seven patients no gross malpositioning of the components could be identified on the post-operative radiographs. Dislocation is the major concern after primary THR for the treatment of intracapsular femoral neck fractures. 27,28 In our series we observed a difference in rate of dislocation between the posterolateral approach and anterolateral approach (p = 0.022). In previous studies, the rate of dislocation after THR in patients with fractures of the femoral neck using the posterolateral approach ranged between 13% and 29%. 10,12,29-31 This difference has also been noted by a recent meta-analysis examining the stability of the hip after hemiarthroplasty. 32 Four surgical options for patients with intracapsular fractures of the femoral neck are well supported in the orthopaedic literature: reduction with internal fixation, unipolar or bipolar hemiarthroplasty, and THR. Analysis of these four surgical treatment options shows that arthroplasty is the most cost-effective treatment when complication rate, mortality, reoperation rate, and function are evaluated during a two-year post-operative period. 33 We have not evaluated cost-effectiveness but the expense of THR will be higher in the short term VOL. 92-B, No. 10, OCTOBER 2010

7 1428 M. P. J. VAN DEN BEKEROM, E. F. HILVERDINK, I. N. SIEREVELT, ET AL because of the additional acetabular component, additional cement, and increased duration of the operation. Elsewhere the estimated costs of the components of a THR ($1274) have been shown to be higher than hemiarthroplasty ($725). 34 Taking into account complication rates, mortality, revision rates, and function, others concluded that THR was more cost-effective than internal fixation, unipolar or bipolar hemiarthroplasty. 33 Our study has some limitations as clinical variables were assessed by an observer who was not blinded to the type of surgical intervention which may have introduced a risk of bias. We used per protocol analyses because this was a commonly used method in 1995 when the study was initiated. The blood loss was measured but the need for blood transfusion was not evaluated and complications after discharge from hospital, except dislocations and revision operations, were not recorded. Finally the modified HHS without the physical examination was used. Historically randomised controlled trials have been scarce in orthopaedic literature but should play a major role in determining best practices for fracture care. 35 The strengths of the present study include its multicentre prospectively computer generated randomisation design with an appropriate sample size. The strict inclusion criteria clearly define the population to whom the results can be generalised. The populations of both groups were comparable at initiation of the study and evaluation was performed after adequate long-term follow-up. Further randomised trials are required to investigate if a THR is beneficial in a subgroup of, for example, very active patients with a fracture of the femoral neck. Listen live Listen to the abstract of this article at The authors are grateful to the local ARTHRO trial co-investigators: D. F. de Zwart (St. Antonius Hospital, Sneek), D. M. Werkman (St. Deventer Hospitals), L. Schuman (Slotervaart Hospital, Amsterdam), J. de Waal Malefijt (St. Elisabeth Hospital, Tilburg), J. B. A. van Mourik (Maxima Medical Center, Veldhoven), and C. F. van der Jagt (Laurentius Hospital, Roermond) and the continuous logistical support of the AO Documentation Centre, Davos, Switzerland. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. References 1. Johnell O, Kanis JA. An estimate of the worldwide prevalence and disability associated with osteoporotic fractures. Osteoporos Int 2006;17: Johnell O, Kanis JA. An estimate of the worldwide prevalence, mortality and disability associated with hip fracture. Osteoporos Int 2004;15: Parker MJ, Gurusamy K. Internal fixation versus arthroplasty for intracapsular proximal femoral fractures in adults. The Cochrane Library, 2006, issue 4. CD Chichester: John Wiley & Sons, Tidermark J. Quality of life and femoral neck fractures. Acta Orthop Scand Suppl 2003;74: 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-A: Parker MJ, Gurusamy K. Arthroplasties (with and without bone cement) for proximal femoral fractures in adults. In: The Cochrane Library, 2006, Issue 3. CD Chichester: John Wiley & Son, Parker MJ, Khan RJ, Crawford J, Pryor GA. Hemiarthroplasty versus internal fixation for displaced intracapsular hip fractures in the elderly: a randomised trial of 455 patients. J Bone Joint Surg [Br] 2002;84-B: Bhandari M, Devereaux PJ, Tornetta P 3rd, et al. Operative management of displaced femoral neck fractures in elderly patients: an international survey. J Bone Joint Surg [Am] 2005;87-A: Iorio R, Schwartz B, Macaulay W, et al. Surgical treatment of displaced femoral neck fractures in the elderly: a survey of the American Association of Hip and Knee Surgeons. 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