At mid- to long-term follow-up after proximal hamstring tendon avulsion; there was greater fatty infiltration, muscle atrophy and strength deficit in the hamstring muscles of the injured leg than in the uninjured leg.

BACKGROUND: Proximal hamstring tendon avulsions (PHAs) may be treated nonoperatively or operatively. Little is known about the result of the injury, and its treatment, on the quality and function of the hamstring muscle after healing and rehabilitation. We hypothesized that the injured leg would have greater fatty infiltration and atrophy than the uninjured leg at follow-up and that these findings would correlate to muscle weakness. METHODS: In a cross-sectional cohort study, 48 patients treated for PHA, either operatively or nonoperatively, were re-examined 2-11 years post-treatment. We measured muscle strength with isokinetic strength tests, and muscle volume and fatty infiltration with MRI. Primary outcomes were hamstring muscle quality, quantified by outlining the cross-sectional area slice-by-slice, and the degree of fatty infiltration estimated using the Goutallier grading method. Secondary outcome was concentric isokinetic hamstring muscle strength measured using BioDex at 60°/sec and tendon attachment assessed on MRI. Comparisons with the outcomes of the uninjured leg were made. RESULTS: The total hamstring muscle volume was on average reduced by 9% (SD ± 11%, p < 0.001) compared to that of the uninjured leg. Fatty infiltration was significantly more severe in the injured hamstrings than in the uninjured hamstrings (p < 0.001). This was also true when only analyzing operatively treated patients. The reduction in muscle volume and increase in fatty infiltration correlated significantly (r = 0.357, p = 0.013), and there was also a statistically significant correlation with muscle atrophy and reduction in isokinetic strength (r = 494, p < 0.001). CONCLUSION: PHA injuries result in fatty infiltration and muscle atrophy and the muscle quality impairment correlates with residual muscle weakness.

Exploring the Perth Hamstring Assessment Tool and Lower Extremity Functional Scale in a Proximal Hamstring Avulsion Cohort: A Cross-sectional Study.

BACKGROUND: The goal of treatment for a proximal hamstring avulsion (PHA) is an objectively restored muscle and a subjectively satisfied, pain-free patient at follow-up. Different self-reported and performance-based outcome measures have been used to evaluate recovery, but their validity is poorly investigated. PURPOSE: To investigate (1) the correlation between the commonly used self-reported outcome measurements, the Perth Hamstring Assessment Tool (PHAT) and the Lower Extremity Functional Scale (LEFS); (2) to what extent these scores can be explained by physical dysfunction as measured by performance-based tests; (3) whether performance-based tests can discriminate between the injured and uninjured extremity; and (4) which activity limitations are perceived by patients several years after the injury. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: We included a consecutive series of patients treated for or diagnosed with PHA in our department between 2007 and 2016 having at least 2 tendons avulsed from the ischial tuberosity. Participants attended 2 study visits, answered questionnaires (PHAT, LEFS, and Patient-Specific Functional Scale [PSFS]), and performed physical performance-based tests (single-leg hop tests, single-step down test, and isometric and isokinetic strength tests). RESULTS: A total of 50 patients were included (26 men [52%], 24 women [48%]; mean age, 50.9 years [SD, 9.8 years]). The mean follow-up time was 5.5 years (SD, 2.7 years), and 74% had been surgically treated. The correlation between PHAT and LEFS was strong (r = 0.832) and statistically significant (P < .001). Seven of the performance-based tests exhibited a statistically significant but weak correlation with LEFS (0.340-0.488) and 3 of the tests to PHAT (-0.304 to 0.406). However, only peak torque could significantly discriminate between the extremities. The activity limitation most commonly mentioned in PSFS was running (16 patients [32%]). CONCLUSION: Although PHAT and LEFS correlated strongly, the correlations between functional tests and the patient-reported outcome scores were weak, and most functional tests failed to discriminate between the injured and uninjured lower extremity in patients with PHA 5 years after injury. In general, patients alleged few activity limitations, but running difficulty was a common sequela after PHA.

Primary hemiarthroplasty for the elderly patient with cognitive dysfunction and a displaced femoral neck fracture: a prospective, observational cohort study.

BACKGROUND: At least one-third of hip fracture patients have some degree of impaired cognitive status, which may complicate their postoperative rehabilitation. AIM: We aimed to describe the outcome for elderly patients with cognitive dysfunction operated with hemiarthroplasty (HA) for a femoral neck fracture and to study the impact postoperative geriatric rehabilitation has on functional outcome up to 1 year after surgery. METHODS: 98 patients with a displaced femoral neck fracture with a mean age of 86 years were included and followed up to 1 year. The outcomes were hip-related complications and reoperations, the capacity to return to previous walking ability, health-related quality of life, hip function and mortality. RESULTS: The prevalence of hip complications leading to a major reoperation was 6% and the 1-year mortality rate was 31%. The lack of geriatric rehabilitation was correlated with poorer outcomes overall and those who receive geriatric rehabilitation were less likely to be confined to a wheelchair or bedridden at the 1-year follow-up. CONCLUSIONS: Hemiarthroplasty is an acceptable option for elderly patients with a displaced femoral neck fracture and cognitive dysfunction. A lack of structured rehabilitation is associated with a significant deterioration in walking ability despite a well-functioning hip. However, the causality of this could be due to selection bias of healthier patients being sent to geriatric rehabilitation.

The proximal hamstring avulsion clinical trial (PHACT)-a randomised controlled non-inferiority trial of operative versus non-operative treatment of proximal hamstrings avulsions: study protocol.

INTRODUCTION: The treatment of proximal hamstring avulsions is controversial. While several trials have investigated the outcome for patients treated surgically, there is today no prospective trial comparing operative treatment with non-operative treatment. This protocol describes the design for the proximal hamstring avulsion clinical trial (PHACT)-the first randomised controlled trial of operative versus non-operative treatment for proximal hamstring avulsions. METHODS AND ANALYSIS: PHACT is a multicentre randomised controlled trial conducted across Sweden, Norway and Finland. Eligible patients (60 participants/treatment arm) with a proximal hamstring avulsion of at least two of three tendons will be randomised to either operative or non-operative treatment. Participants allocated to surgery will undergo reinsertion of the tendons with suture anchors. The rehabilitation programme will be the same for both treatment groups. When patient or surgeon equipoise for treatment alternatives cannot be reached and randomisation therefore is not possible, patients will be invited to participate in a parallel observational non-randomised cohort. The primary outcome will be the patient-reported outcome measure Perth hamstring assessment tool at 24 months. Secondary outcomes include the Lower Extremity Functional Score, physical performance and muscle strength tests, patient satisfaction and MR imaging. Data analysis will be blinded and intention-to-treat analysis will be preformed. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Ethical Committee of Uppsala University (DNR: 2017-170) and by the Norwegian ethical board (REC: 2017/1911). The study will be conducted in agreement with the Helsinki declaration. The findings will be disseminated in peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT03311997.

HOPE-Trial: Hemiarthroplasty Compared with Total Hip Arthroplasty for Displaced Femoral Neck Fractures in Octogenarians: A Randomized Controlled Trial.

BACKGROUND: The choice of primary hemiarthroplasty or total hip arthroplasty in patients ≥80 years of age with a displaced femoral neck fracture has not been adequately studied. As the number of healthy, elderly patients ≥80 years of age is continually increasing, optimizing treatments for improving outcomes and reducing the need for secondary surgery is an important consideration. The aim of the present study was to compare the results of hemiarthroplasty with those of total hip arthroplasty in patients ≥80 years of age. METHODS: This prospective, randomized, single-blinded trial included 120 patients with a mean age of 86 years (range, 80 to 94 years) who had sustained an acute displaced femoral neck fracture <36 hours previously. The patients were randomized to treatment with hemiarthroplasty (n = 60) or total hip arthroplasty (n = 60). The primary end points were hip function and health-related quality of life at 2 years. Secondary end points included hip-related complications and reoperations, mortality, pain in the involved hip, activities of daily living, surgical time, blood loss, and general complications. The patients were reviewed at 3 months and 1 and 2 years. RESULTS: We found no differences between the groups in terms of hip function, health-related quality of life, hip-related complications and reoperations, activities of daily living, or pain in the involved hip. Hip function, activities of daily living, and pain in the involved hip deteriorated in both groups compared with pre-fracture values. The ability to regain previous walking function was similar in both groups. CONCLUSIONS: We found no difference in outcomes after treatment with either hemiarthroplasty or total hip arthroplasty in active octogenarians and nonagenarians with a displaced femoral neck fracture up to 2 years after surgery. Hemiarthroplasty is a suitable procedure in the short term for this group of patients. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Reduced periprosthetic fracture rate when changing from a tapered polished stem to an anatomical stem for cemented hip arthroplasty: an observational prospective cohort study with a follow-up of 2 years.

Background and purpose - Straight collarless polished tapered stems have been linked to an increased risk for periprosthetic femur fractures in comparison with anatomically shaped stems, especially in elderly patients. Therefore, we evaluated the effect of an orthopedic department's full transition from the use of a cemented collarless, polished, tapered stem to a cemented anatomic stem on the cumulative incidence of postoperative periprosthetic fracture (PPF). Patients and methods - This prospective single-center cohort study comprises a consecutive series of 1,077 patients who underwent a cemented hip arthroplasty using either a collarless polished tapered stem (PTS group, n = 543) or an anatomic stem (AS group, n = 534). We assessed the incidence of PPF 2 years postoperatively and used a Cox regression model adjusted for age, sex, ASA class, cognitive impairment, BMI, diagnosis, and surgical approach for outcome analysis. Results - Mean age at primary surgery was 82 years (49-102), 73% of the patients were female, and 75% underwent surgery for a femoral neck fracture. The PPF rate was lowered from 3.3% (n = 18) in the PTS group to 0.4% (n = 2) in the AS group. The overall complication rate was also lowered from 8.8% in the PTS group to 4.5% in the AS group. In the regression model only cognitive dysfunction (HR 3.8, 95% CI 1.4-10) and the type of stem (PTS vs AS, HR 0.1, CI 0.0-0.5) were correlated with outcome. Interpretation - For elderly patients with poor bone quality use of cemented anatomic stems leads to a substantial reduction in periprosthetic fracture rate without increasing other complications.

Patient-reported outcomes after surgical and non-surgical treatment of proximal hamstring avulsions in middle-aged patients.

OBJECTIVES: In the literature on proximal hamstring avulsions, only two studies report the outcomes of non-surgically treated patients. Our objective was to compare subjective recovery after surgical and non-surgical treatment of proximal hamstring avulsions in a middle-aged cohort. METHODS: We included 47 patients (33 surgically and 14 non-surgically treated) with a mean (SD) age of 51 (±9) years in a retrospective cohort study. Follow-up time mean (SD) of 3.9 (±1.4) years. The outcome variables were the Lower Extremity Functional Scale (LEFS) and questions from the Proximal Hamstring Injury Questionnaire. Outcome variables were adjusted in regression models for gender, age, American Society of Anestesiologits (ASA) classification and MRI findings at diagnosis. RESULTS: The baseline characteristics showed no differences except for the MRI result, in which the surgically treated group had a larger proportion of tendons retracted ≥ 2 cm. The mean LEFS score was 74 (SD±12) in the surgically treated cohort and 72 (SD±16) in the non-surgically treated cohort. This was also true after adjusting for confounders. The only difference in outcome at follow-up was the total hours performing physical activity per week, p=0.02; surgically treated patients reported 2.5 hours or more (5.2 vs 2.7). CONCLUSION: This study on middle-aged patients with proximal hamstring avulsions was unable to identify any difference in patient-reported outcome measures between surgically and non-surgically treated patients. The vast majority of patients treated surgically had complete proximal hamstring avulsions with ≥ 2 cm of retraction. We conclude that to obtain an evidence-based treatment algorithm for proximal hamstring avulsions studies of higher scientific level are needed.

Loss of offset after pertrochanteric hip fractures affects hip function one year after surgery with a short intramedullary nail. A prospective cohort study.

PURPOSE: We hypothesised that protruding collum screws in intramedullary nails used for pertrochanteric fractures cause lateral pain/discomfort and that loss of offset relates to poorer hip function. METHODS: Seventy-six patients with an acute pertrochanteric femoral fracture AO types A1 and A2 were operated upon using a short intramedullary nail and were included in a prospective observational cohort study and followed-up for one year. The main outcome variables were lateral pain and hip function as evaluated with the Harris Hip Score. The main exposure was compression along the collum screw and lateral protrusion measured by anteroposterior X-ray images. Perioperative images were compared to images at the follow-up visit. Outcome variables were adjusted in regression models for reduction, fracture type, body mass index, sex and age. RESULTS: A total of 28 (36 %) patients experienced lateral pain at one year. We found a correlation between lateral protrusion and lateral pain, adjusted OR 4.5 per protruding centimetre (95 % CI, 1.1-17.5). Collum compression correlated with a poorer outcome with Harris Hip Score -14.2 per compressed centimetre (95 % CI, -21.8 to -6.7). CONCLUSIONS: In patients with type A1 and A2 pertrochanteric fractures operated on using intramedullary nailing, a large compression and lateral protrusion of the collum screw are associated with poorer hip function and lateral pain. New technical improvements for implants should focus on these factors to improve functional outcome after surgery.

HOPE-trial: hemiarthroplasty compared to total hip arthroplasty for displaced femoral neck fractures in the elderly-elderly, a randomized controlled trial.

BACKGROUND: A femoral neck fracture (FNF) is a common cause of suffering and premature death in the elderly population. Optimizing the treatment for improved outcome and a reduced need for secondary surgery is important both for the patient and the society. The choice of primary total or hemiarthroplasty in patients over eighty years are controversial. We hypothesized that total hip arthroplasty has an equal or better outcome in patient-reported outcome compared with hemiarthroplasty. METHODS/DESIGN: A prospective, randomized, single-blinded trial will be conducted. We will include 120 patients, 80 years of age and over with an acute (<36 h) displaced femoral neck fracture. The patients will be randomized in a 1:1 ratio to either total hip arthroplasty or hemiarthroplasty. The primary endpoints are Harris hip Score and EQ-5D. Secondary endpoints include pain measured with visual analogue scale, surgical time, reoperations, complications and radiological measurement of erosion in patients operated with hemiarthroplasty. Follow-up will be performed postoperatively after three months, 1, 2, 4 and 10 years. DISCUSSION: To our knowledge, this is the first randomized controlled trial comparing total hip arthroplasty and hemiarthroplasty for displaced femoral neck fracture in patients age 80 years and over. TRIAL REGISTRATION: Clinicaltrial.gov: NCT02246335.

Unipolar hemiarthroplasty versus bipolar hemiarthroplasty in patients with displaced femoral neck fractures: a four-year follow-up of a randomised controlled trial.

PURPOSE: The treatment of choice for a displaced femoral neck fracture in the most elderly patients is a cemented hemiarthroplasty (HA). The optimal design, unipolar or bipolar head, remains unclear. The possible advantages of a bipolar HA are a better range of motion and less acetabular wear. The aim of this study was to evaluate hip function, health related quality of life (HRQoL), surgical outcome and acetabular erosion in a medium-term follow-up. METHODS: One hundred and twenty patients aged 80 or more with a displaced fracture of the femoral neck (Garden III and IV) were randomised to treatment with a cemented Exeter HA using a unipolar or a bipolar head. All patients were able to walk independently, with or without aids, before surgery. Follow-ups were performed at four, 12, 24 and 48 months postoperatively. Assessments included HRQoL (EQ-5D index score), hip function (Harris hip score [HHS]) and radiological acetabular erosion. RESULTS: The mean EQ-5D index score was generally higher among the patients with bipolar hemiarthroplasties at the follow-ups with a significant difference at 48 months: unipolar HAs 0.59 and bipolar HAs 0.70 (p = 0.04). There was an increased rate of acetabular erosion among the patients with unipolar hemiarthroplasties at the early follow-ups with a significant difference at 12 months (unipolar HAs 20% and bipolar HAs 5%, p = 0.03). At the later follow-ups the incidence of acetabular erosion accelerated in the bipolar group, and there were no significant differences between the groups at the 24- and 48-month follow-ups. There was no difference in HHS or reoperation rate between the groups at any of the follow-ups. CONCLUSION: The bipolar HAs seem to result in better HRQoL beyond the first two years after surgery compared to unipolar HAs. Bipolar HAs displayed a later onset of acetabular erosion compared to unipolar HAs.

Internal fixation versus cemented hemiarthroplasty for displaced femoral neck fractures in patients with severe cognitive dysfunction: a randomized controlled trial.

OBJECTIVES: To compare the outcome of internal fixation (IF) versus a cemented hemiarthroplasty (HA) in patients with a displaced femoral neck fracture and a severe cognitive dysfunction. DESIGN: A prospective randomized controlled trial. SETTING: A tertiary care university hospital. PATIENTS: Sixty patients with a displaced femoral neck fracture were randomized to IF (n = 30) or HA (n = 30). All patients suffered from severe cognitive dysfunction but were able to walk before the fracture. INTERVENTION: IF using 2 cannulated screws or HA using a cemented Exeter unipolar arthroplasty. MAIN OUTCOME MEASUREMENTS: Patients were reviewed at 4, 12, and 24 months after the fracture. Outcome assessments included complications, reoperations, hip function (Charnley score), and health-related quality of life (EQ-5Dindex score). RESULTS: A total of 8 patients were reoperated (14%); 7 in the IF group and 1 in the HA group. The EQ-5Dindex score at the follow-ups were generally lower in the IF group compared with the HA group with a significant difference at 12 months (P = 0.03). No difference was seen in hip function, general complications, or mortality between the groups. CONCLUSIONS: HA seems to provide a safe option with better health-related quality of life and less risk for reoperations compared with IF for these patients. LEVEL OF EVIDENCE: Therapeutic level II.

Unipolar versus bipolar Exeter hip hemiarthroplasty: a prospective cohort study on 830 consecutive hips in patients with femoral neck fractures.

BACKGROUND: Hip replacement using a hemiarthroplasty (HA) is a common surgical procedure in elderly patients with fractures of the femoral neck. Data from the Swedish Hip Arthroplasty Register suggest that there is a higher risk for revision surgery with the bipolar HA compared with the unipolar HA. PURPOSE: In this study we analysed the reoperation and the dislocation rates for Exeter HAs in patients with a displaced femoral neck fracture, comparing the unipolar and bipolar prosthetic designs. Additionally, we compared the outcome for HAs performed as a primary intervention with those performed secondary to failed internal fixation. METHODS: We studied 830 consecutive Exeter HAs (427 unipolar and 403 bipolar) performed either as a primary operation for a displaced fracture of the femoral neck or as a secondary procedure after failed internal fixation of a fracture of the femoral neck. Cox regression analyses were performed to evaluate factors associated with reoperation and prosthetic dislocation. Age, gender, the surgeon's experience, indication for surgery (primary or secondary) and type of HA (unipolar or bipolar) were tested as independent variables in the model. RESULTS: The prosthetic design (uni- or bipolar) had no influence on the risk for reoperation or dislocation, nor had the age, gender or the surgeon's experience. The secondary HAs were associated with a significantly increased risk for reoperation (HR 2.6, CI 1.5-4.5) or dislocation (HR 3.3, CI 1.4-7.3) compared to the primary HAs. We found no difference in the risk for reoperation or dislocation when comparing Exeter unipolar and bipolar HAs, but special attention is called for to reduce the risk of prosthesis dislocation and reoperation after a secondary HA.

Comparison of bipolar hemiarthroplasty with total hip arthroplasty for displaced femoral neck fractures: a concise four-year follow-up of a randomized trial.

We performed a four-year follow-up of a randomized controlled trial involving 120 elderly patients with an acute displaced femoral neck fracture who were randomized to treatment with either a bipolar hemiarthroplasty or a total hip arthroplasty. The difference in hip function (as indicated by the Harris hip score) in favor of the total hip arthroplasty group that was previously reported at one year persisted and seemed to increase with time (mean score, 87 compared with 78 at twenty-four months [p < 0.001] and 89 compared with 75 at forty-eight months [p < 0.001]). The health-related quality of life (as indicated by the EuroQol [EQ-5D(index)] score) was better in the total hip arthroplasty group at the time of each follow-up, but the difference was significant only at forty-eight months (p < 0.039). These results confirm the better results in terms of hip function and quality of life after total hip arthroplasty as compared with hemiarthroplasty in elderly, lucid patients with a displaced fracture of the femoral neck.

Unipolar hemiarthroplasty versus bipolar hemiarthroplasty in the most elderly patients with displaced femoral neck fractures: a randomised, controlled trial.

PURPOSE: Hemiarthroplasty (HA) is generally considered to be the treatment of choice in the most elderly patients with a displaced fracture of the femoral neck. However, there is inadequate evidence to support the choice between unipolar HA or bipolar HA. The primary aim of this study was to analyse the outcome regarding hip function and health-related quality of life (HRQoL) in patients randomised to either a unipolar or bipolar HA. The secondary aim was to analyse the degree of acetabular erosion and its influence upon outcome. METHODS: One hundred twenty patients with a mean age of 86 years and an acute displaced fracture of the femoral neck were randomly allocated to treatment by either unipolar or bipolar HA. Outcome measurements included hip function (Harris Hip Score, HHS), HRQoL (EQ-5D) and acetabular erosion. The patients were summoned at four and 12 months for follow-up. RESULTS: There were no significant differences between the groups regarding complications. The HHS scores were equal at both follow-ups, but there was a trend towards better HRQoL in the bipolar HA group at four months, EQ-5D (index) score 0.62 vs 0.54 (p = 0.06). Twenty percent of the patients in the unipolar HA group displayed acetabular erosion at the 12-month follow-up compared to 5% in the bipolar HA group (p = 0.03), and there were trends towards worse hip function and HRQoL among patients with acetabular erosion compared to those without: HHS scores 70.4 and 79.3, respectively (p = 0.09), and EQ-5D (index) scores 0.48 and 0.63, respectively (p = 0.13). CONCLUSION: Unipolar HA and bipolar HA appeared to produce equivalent clinical outcomes after one year, but the significantly higher incidence of acetabular erosion in the unipolar HA group may imply that bipolar HA should be the preferred treatment.

Responsiveness of the Short Musculoskeletal Function Assessment (SMFA) in patients with femoral neck fractures.

PURPOSE: The aim of this study was to evaluate the internal and external responsiveness of the Short Musculoskeletal Function Assessment (SMFA), i.e. the instrument's ability to capture clinically important changes, in patients with hip fractures within the context of a randomized controlled trial. METHODS: To evaluate the internal responsiveness of the SMFA, the observed change and the standardized response mean (SRM) in relation to the change in the Dysfunction Index and the Bother Index were calculated. In order to calculate external responsiveness, an external criterion (EC) was constructed by using the Harris hip score. Receiver operating characteristic (ROC) curves and logistic regression analysis were used in the evaluation. RESULTS: Both the Bother and the Dysfunction SMFA indices displayed good internal responsiveness as expressed by significant change scores and by moderate and large SRMs, 0.76 and 0.96, respectively. The ROC curve and logistic regression analyses showed that both indices had acceptable external responsiveness and were able to discriminate between patients with a less good outcome versus a moderately good or good outcome based on the EC while the ability to differ between patients with moderately good versus a good outcome was limited. The percentage of correctly classified cases was 64% (good/moderately good), 80% (good/less good), and 74% (moderately good/less good) for both the Dysfunction and Bother Indices. CONCLUSIONS: The SMFA had good overall responsiveness in patients with hip fractures and, based on our results, we conclude that the SMFA can be recommended for use as one of the measures to evaluate the outcome after a hip fracture.

Dislocation of total hip replacement in patients with fractures of the femoral neck.

BACKGROUND: Total hip replacement is increasingly used in active, relatively healthy elderly patients with fractures of the femoral neck. Dislocation of the prosthesis is a severe complication, and there is still controversy regarding the optimal surgical approach and its influence on stability. We analyzed factors influencing the stability of the total hip replacement, paying special attention to the surgical approach. PATIENTS AND METHODS: We included 713 consecutive hips in a series of 698 patients (573 females) who had undergone a primary total hip replacement (n = 311) for a non-pathological, displaced femoral neck fracture (Garden III or IV) or a secondary total hip replacement (n = 402) due to a fracture-healing complication after a femoral neck fracture. We used Cox regression to evaluate factors associated with prosthetic dislocation after the operation. Age, sex, indication for surgery, the surgeon's experience, femoral head size, and surgical approach were tested as independent factors in the model. RESULTS: The overall dislocation rate was 6%. The anterolateral surgical approach was associated with a lower risk of dislocation than the posterolateral approach with or without posterior repair (2%, 12%, and 14%, respectively (p < 0.001)). The posterolateral approach was the only factor associated with a significantly increased risk of dislocation, with a hazards ratio (HR) of 6 (2-14) for the posterolateral approach with posterior repair and of 6 (2-16) without posterior repair. INTERPRETATION: In order to minimize the risk of dislocation, we recommend the use of the anterolateral approach for total hip replacement in patients with femoral neck fractures.