Modes of failure of hip hemiarthroplasty for femoral neck fracture
==================================================================

* Taranjit Tung
* Trevor C. Gascoyne
* Elly Trepman
* Carole H. Stipelman
* Sarah Tran
* Eric R. Bohm
* Colin D. Burnell
* David R. Hedden
* Thomas R. Turgeon

## Abstract

**Background:** Hemiarthroplasty is a common treatment for displaced femoral neck fractures, but limited Canadian data are available about hemiarthroplasty failure. We evaluated the frequency and predictors of hemiarthroplasty failure in Manitoba.

**Methods:** In this retrospective multicentre province-wide study, billing and joint registry databases showed 4693 patients who had hemiarthroplasty for treatment of femoral neck fracture in Manitoba over an 11-year period (2005–2015), including 155 hips with subsequent reoperations (open or closed) for treatment of hemiarthroplasty failure. Hospital records were reviewed to identify modes of hemiarthroplasty failure, comorbidities and reoperations. Data were analyzed using χ2 test and Poisson and γ regression models.

**Results:** During our study period, 155 hips (154 patients [3%]) underwent 230 reoperations. Of these, 131 hips (85%) initially had an uncemented unipolar modular implant. Indications for first-time reoperation included periprosthetic femur fracture (49 hips [32%]), dislocation (45 hips [29%]), acetabular wear (28 hips [18%]) and infection (26 hips [17%]). There were 46 hips (30%) that had 2 or more reoperations. Reoperation for dislocation was associated with presence of dementia; acetabular wear was associated with absence of dementia. Time from hemiarthroplasty to reoperation was associated inversely with age at hemiarthroplasty, dislocation and dementia and was directly associated with acetabular wear. The risk of having 2 or more reoperations was associated independently with dislocation, infection, and alcohol abuse.

**Conclusion:** Hemiarthroplasty for femoral neck fracture in Manitoba had a low frequency of failure. Risk factors for multiple reoperations included dislocation, infection and alcohol abuse.

Acute displaced intracapsular femoral neck fractures comprise almost half of all hip fractures, and most of these fractures in elderly patients in the developed world are treated surgically with hip hemiarthroplasty, total hip arthroplasty, or internal fixation.1–4 Hemiarthroplasty is also performed for femoral neck nonunion, failed screw fixation and pathologic femoral neck fracture.

There is controversy about the optimal surgical technique for hemiarthroplasty, including surgical approach (anterior, lateral or posterior), endoprosthesis head (unipolar modular, unipolar monoblock, or bipolar) and stem fixation (cemented or uncemented).5 Femoral component fixation in hemiarthroplasty outside North America commonly involves use of cement,6–8 but uncemented, press-fit fixation frequently is used in North America.9 The most common causes for hemiarthroplasty reoperation globally include acetabular wear, infection, instability, aseptic loosening and periprosthetic fracture, but limited Canadian data are available about hemiarthroplasty failure modes.10

We hypothesized that hemiarthroplasty for femoral neck fracture in Manitoba has infrequent failure and that the failure rate may be comparable to that in other geographic regions. The purpose of this study was to determine the frequency and predictors of modes of failure of hemiarthroplasty in Manitoba.

## Methods

### Patients

This study was a retrospective medical record review of patients who underwent hemiarthroplasty for treatment of a femoral neck fracture in the province of Manitoba over an 11-year period (Jan. 1, 2005, to Dec. 31, 2015) and who required subsequent orthopedic procedures on the ipsilateral hip. Data were collected from March to October 2017, which was a mean of 7 ± 3 years after the hemiarthroplasty. We identified all documented patients by querying the Manitoba Joint Replacement Registry and Manitoba Health Medical Claims Registry with 4 primary billing codes for hemiarthroplasty (0870 fracture, femur, neck, prosthetic replacement; 1149 total hip arthroplasty, femoral head replacement type; 1423 bipolar hip arthroplasty; 1424 unipolar hip arthroplasty) and 8 secondary billing codes for the subsequent procedures (1154 total hip arthroplasty, when previous uncemented Austin Moore prosthesis, cup, or plates require removal; 1175 arthrodesis, hip; 1332 dislocation, hip, closed reduction; 1334 dislocation, hip, open reduction; 1414 revision of hemiarthroplasty to total hip; 1415 total hip arthroplasty; 1422 removal of hip prosthesis without replacement; 1425 resection, femoral head [Girdlestone procedure]).11 As the Manitoba Health Medical Claims Registry data did not distinguish between subsequent procedures performed on the ipsilateral versus contralateral hip, the side of the subsequent procedure was determined from manual review of paper medical records and operative reports for patients who had a subsequent procedure. The query showed 4693 patients who had hemiarthroplasty for treatment of a femoral neck fracture, and we included all 155 hips (154 patients) that underwent hemiarthroplasty for acute femoral neck fracture, pathologic femoral neck fracture, or complications of previous treatment of femoral neck fracture, such as femoral neck nonunion or hardware cutout, and had subsequent reoperation for hemiarthroplasty failure. There was 1 patient who had bilateral asynchronous hemiarthroplasties for femoral neck fractures, with the right occurring 26 months before the left femoral neck fracture, and both sides required subsequent procedures; these 2 hips were treated independently in the analyses because there was no temporal or apparent clinical association between the right and left femoral neck fractures other than medical comorbidities. There were 12 additional patients who were excluded from the study because they had operations that were total hip arthroplasties miscoded as hemiarthroplasty or were on the contralateral hip and unrelated to the hemiarthroplasty.

### Evaluation

Hospital records were reviewed to confirm that the identified patients had a hemiarthroplasty and subsequent orthopedic procedure on the ipsilateral hip. A reoperation was defined as any procedure after the hemiarthroplasty and included fixation of periprosthetic fracture, closed or open reduction of dislocation, irrigation and débridement for infection, and revision of any components. Information from the records was extracted, including mode of failure of the hemiarthroplasty and indications for reoperations including periprosthetic fracture, dislocation, acetabular wear and infection. In addition, hospital records were reviewed for clinical factors associated with risks of hemiarthroplasty failure, such as presence of diabetes, inflammatory arthritis, steroid use, smoking, dementia, seizure disorder, stroke, radiation treatment, history of falls, alcohol abuse and noncompliance with hip precautions. Radiographs were not analyzed because they were unavailable or of insufficient uniformity of technique or quality for standardized measurements of radiographic parameters for 122 of 230 reoperations (53%).

### Statistical analysis

Data analysis was performed using statistical software (STATA/IC, version 15.1, StataCorp). Data were reported as numbers and percentages of hips or as means with standard deviations (SD). Associations between comorbidities or surgical approach and indications for reoperation were evaluated using χ2 test or modified univariable or multivariable Poisson regression to compute incidence rate ratios (IRRs) that accounted for the possible correlation between multiple operations in the same patient.12 The association between covariates and time from hemiarthroplasty to reoperation was evaluated using multivariable mixed-effects γ regression, nested by patient to control for multiple operations in individual patients; γ regression is a generalized linear model that may correct for non-normal distribution of data. The relation between independent variables and the risk of the binary outcome (≥ 2 reoperations v. 1 reoperation) was modelled with multivariable mixed-effects binary Poisson regression, with reoperations clustered within patient and with robust standard errors, to compute risk ratios adjusted for potential confounding variables. Risk ratios and IRRs are reported with standard errors (SE) and 95% confidence intervals (CIs). Results were considered statistically significant at *p* < 0.05.

### Ethics approval

The study was reviewed and approved by the University of Manitoba Health Research Ethics Board.

## Results

The registry query showed 4693 patients who underwent hemiarthroplasty for a femoral neck fracture at 7 hospitals in the province. Reoperations on the ipsilateral hip after hemiarthroplasty were performed in 155 hips (154 patients [3%]). Most hips with reoperation were in women who had a unipolar modular uncemented hemiarthroplasty for an acute femoral neck fracture and first reoperation at a mean of 1.5 years after the hemiarthroplasty (Table 1 and Table 2). Most hips had only 1 or 2 reoperations, but 17 hips (11%) had 3 or more reoperations (Table 1). The most frequent indications for the first reoperation included periprosthetic femur fracture, dislocation, acetabular wear, or infection (Table 3).13 In the 46 hips (30%) that had 2 or more reoperations, the most frequent indications included dislocation or infection (Table 3). The 230 reoperations for treatment of complications in the 155 hips mostly included revision arthroplasty, closed reduction of hip dislocation, or open treatment of infection (Table 4).

View this table:
[Table 1](http://canjsurg.ca/content/65/4/E519/T1)

Table 1 
Demographic and clinical characteristics of patients who had hip hemiarthroplasty and subsequent ipsilateral hip reoperations*

View this table:
[Table 2](http://canjsurg.ca/content/65/4/E519/T2)

Table 2 
Implants and fixation used in hemiarthroplasty*

View this table:
[Table 3](http://canjsurg.ca/content/65/4/E519/T3)

Table 3 
Indications for reoperation after hemiarthroplasty*

View this table:
[Table 4](http://canjsurg.ca/content/65/4/E519/T4)

Table 4 
Reoperations for hemiarthroplasty failure*

Evaluation of the association between comorbidities and indications for reoperation showed that first-time reoperation for dislocation was significantly more frequent in hips of patients who had dementia (20 dislocations in 44 hips [45%]) than in those who did not have dementia (25 dislocations in 110 hips [23%]; *p* = 0.005; comorbidity data missing for 1 hip in 1 patient). In all 229 reoperations for which comorbidity data were available, reoperation for infection was significantly more frequent in patients who had a history of seizures (7 reoperations for infection in all 7 reoperations in patients with seizures [100%]) than in patients who did not have seizures (42 reoperations for infection in 222 reoperations in patients with no seizures [19%]; *p* < 0.001). In the 229 reoperations, reoperation for acetabular wear was significantly more frequent in patients who did not have dementia (28 reoperations for acetabular wear in 151 reoperations in patients with no dementia [19%]) than in patients who had dementia (0 reoperations for acetabular wear in 78 reoperations in patients with dementia [0%]); all 28 reoperations for acetabular wear were in patients who did not have dementia (*p* < 0.001). In all 229 reoperations with data available about the primary hemiarthroplasty surgical approach, there were 96 reoperations for dislocation in 229 reoperations (42%), including 66 of 147 reoperations (45%) after lateral approach, 27 of 78 reoperations (35%) after posterior approach, and 3 of 4 reoperations (75%) after anterior approach (not significant). Univariable mixed-effects Poisson regression showed that the likelihood of reoperation for acetabular wear was inversely associated with age at hemiarthroplasty (IRR 0.94 ± 0.02, 95% CI 0.90–0.98, *p* = 0.002) and age at reoperation (IRR 0.95 ± 0.02, 95% CI 0.92–0.99, *p* = 0.016) and directly associated with time between hemiarthroplasty and reoperation (IRR 1.026 ± 0.005, 95% CI 1.017–1.036, *p* < 0.001).

Multivariable mixed-effects γ regression for first and all reoperations showed that time from hemiarthroplasty to reoperation was inversely associated with age at hemiarthroplasty, dislocation, and dementia as the indication for reoperation (risk ratio < 1), and directly associated with acetabular wear (risk ratio > 1) (Table 5). Infection was inversely associated with time from hemiarthroplasty to reoperation for all reoperations, but not for first reoperation (Table 5). Multivariable mixed-effects binary Poisson regression showed that the risk of 2 or more reoperations compared with 1 reoperation was significantly associated with dislocation, infection and alcohol abuse (Table 6).

View this table:
[Table 5](http://canjsurg.ca/content/65/4/E519/T5)

Table 5 
Multivariable mixed-effects gamma regression: relation between covariates and time from hemiarthroplasty to reoperation*

View this table:
[Table 6](http://canjsurg.ca/content/65/4/E519/T6)

Table 6 
Multivariable mixed-effects binary Poisson regression for risk ratio of ≥ 2 reoperations versus 1 reoperation*

## Discussion

The present study showed that reoperations for treatment of complications after hemiarthroplasty were performed in 3% of patients. Previous studies reported a comparable frequency of reoperation after hemiarthroplasty from 1.3% to 6% of hips.1,9,14–16 Varied factors may contribute to increased complications and reoperation, including patient comorbidities, such as congestive heart failure and alcohol abuse; surgical technique; implant type; and fixation method,3,9,14,16–22 whereas surgeon experience, operative volume and timing of surgery may or may not contribute to the frequency of complications and reoperation.23,24 Although most hemiarthroplasties in the present study were uncemented unipolar and modular, variation of implant type has been reported, such as the common use of unipolar monoblock or modular stems in Australia14 and bipolar stems in Norway,25 with cemented fixation commonly used in Norway and the United Kingdom.1,2,22,25

In our study, the most frequent cause of hemiarthroplasty failure necessitating additional operative (closed or open) procedures included periprosthetic femur fracture, dislocation, acetabular wear and infection. Periprosthetic femur fracture may be affected by implant design, broach-implant mismatch, uncemented hemiarthroplasty, surgeon experience with uncemented stems, and patient factors such as osteoporosis.6,7,26–31 The number of periprosthetic femur fractures in the present study represents fractures that were treated with reoperation and does not include intraoperative periprosthetic femur fractures that were treated with cerclage wiring or conversion to a different stem during the hemiarthroplasty or postoperative periprosthetic femur fractures that were treated nonoperatively. The hemiarthroplasty was uncemented in most hips in this study, and perioperative periprosthetic femur fractures typically are associated with uncemented fixation.29,32 However, the present frequency of 49 hips with periprosthetic femur fractures (first reoperation) in 4693 patients who had hemiarthroplasty (1%) is lower than the 4% frequency reported previously in the UK.7 In contrast with surgeons in other countries,33 Canadian orthopedic surgeons use uncemented stems with 2.6-fold higher frequency than cemented stems in hemiarthroplasties for hip fractures.34 Therefore, surgeon experience with the use of uncemented stems may be a factor associated with decreased frequency of postoperative periprosthetic femur fracture.

The observed association between hemiarthroplasty dislocation and dementia is consistent with previous reports.35,36 However, we did not observe a higher frequency of dislocation with the posterior versus lateral or anterior approaches reported previously,37,38 possibly because most hemiarthroplasties in the present study were performed by experienced orthopedic surgeons or residents under direct supervision. Another previous study showed no difference in dislocation frequency between the posterior and lateral approaches.39 Although inadequate restoration of femoral offset and leg length may be associated with a higher frequency of dislocation,36,40,41 we did not have enough radiographs of sufficient uniformity of technique or quality to evaluate these parameters.

The low frequency of reoperation for acetabular wear observed (28 hips in 4693 patients [0.60%]) is consistent with previous reports on monoblock unipolar and bipolar hemiarthroplasties and cemented or uncemented stems.15,42,43 Reoperation for acetabular wear in the present study was associated with absence of dementia, possibly because of the greater activity level typical in these patients.44 Unipolar hemiarthroplasty is associated with greater acetabular wear and lower health-related quality of life than bipolar hemiarthroplasty within 2 years after initial surgery.45

The frequency of infection in the present study was lower (26 hips in 4693 patients [0.55%]) than reported previously after hemiarthroplasty for femoral neck fracture (1.7%–7.3%),46,47 possibly because our data captured only deep infections that necessitated surgical treatment and not superficial or low-grade infections that were treated nonoperatively. The risk of developing an infection after hemiarthroplasty may be associated with female sex, body mass index greater than 30 kg/m2, glucocorticoid and immunosuppressive drug treatment, previous same-site surgery, concurrent cutaneous, urinary, or abdominal infections,48 chronic residence in a health care institution,49 surgeon experience,50–52 duration of anesthesia,50 operating time,51 mode of wound closure,53 prolonged wound drainage for more than 10 days, deep palpable hematoma, inadequate antibiotic prophylaxis, and postoperative dislocation.48 However, patient age, sex, body mass index, use of uncemented fixation, presence of diabetes, smoking, and inflammatory arthritis were not associated with an increase in the risk of failure by infection versus other modes of hemiarthroplasty failure in our study (data not shown). Although seizures have been associated with the development of bilateral femoral neck fractures,54 literature search showed no previous association between seizure disorder and the risk of developing an infection after hemiarthroplasty for femoral neck fracture. As aseptic loosening was an infrequent cause of hemiarthroplasty failure leading to revision, we were unable to identify any clinical factors associated with the development of aseptic loosening compared with other causes of failure.

### Limitations

Limitations of the present study include those inherent with a retrospective study based on billing data and paper medical records. We did not evaluate total hip arthroplasty as treatment for femoral neck fracture or compare hemiarthroplasty with total hip arthroplasty because total hip arthroplasty was performed less frequently for fracture treatment than hemiarthroplasty in Manitoba during the study period and less frequently for fracture treatment than in Ontario.10,55 In another Canadian study from Alberta, hemiarthroplasty and total hip arthroplasty were combined and not analyzed separately because of potential miscoding of hemiarthroplasty as a total hip arthroplasty, and the frequency of miscoded operations in our study is unknown.56 In addition, we did not evaluate the delay in performing hemiarthroplasty after the acute fracture, which may increase the risk of developing a dislocation and mortality, because the date of fracture frequently was missing.57,58 Furthermore, some variables regarding postoperative care that could have affected outcomes, such as home care or treatment in a rehabilitation centre,59 were not evaluated, and functional assessment of patients was beyond the scope of our study.60 Nevertheless, the present results may be useful as benchmark information for future analyses and quality-improvement efforts focused on femoral neck fractures in an aging population.61

## Conclusion

Hemiarthroplasty for femoral neck fracture has a low frequency of failure, but failure may be associated with substantial morbidity. Despite differences in implant use and fixation techniques, our findings were comparable to those of other studies and registry data globally. Most failures were due to periprosthetic femur fracture, dislocation, acetabular wear and infection.

## Acknowledgement

The authors thank the Health Information Privacy Committee of Manitoba Health, Seniors and Active Living.

## Footnotes

*   **Contributors:** T. Tung, E. Bohm, C. Burnell and T. Turgeon designed the study. S. Tran and D. Hedden acquired the data, which T. Gascoyne, E. Trepman and C. Stipelman analyzed. T. Tung, T. Gascoyne and E. Trepman wrote the article, which all authors reviewed. All authors approved the final version for publication.

*   **Competing interests:** T. Tung and E. Trepman received fellowship support from the Concordia Foundation, DePuy Synthes, and Smith & Nephew. T. Gascoyne, E. Bohm, C. Burnell, D. Hedden, and T. Turgeon have received institutional funding from DePuy, Smith & Nephew, Zimmer Biomet, Hip Innovation Technology, and Össur. E. Bohm is a consultant to Stryker Canada and declares receiving payment for expert testimony from the Government of British Columbia. He is also an editorial board member of *The Bone and Joint Journal*. C. Burnell reports travel reimbursement from Hip Innovation Technology. D. Hedden was a paid consultant for Smith & Nephew. No other competing interests were declared.

*   **Funding:** This study was supported by a research grant from the Manitoba Medical Service Foundation. T. Tung and E. Trepman received fellowship support from the Concordia Foundation, DePuy Synthes, and Smith & Nephew.

*   Accepted August 23, 2021.

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY-NC-ND 4.0) licence, which permits use, distribution and reproduction in any medium, provided that the original publication is properly cited, the use is noncommercial (i.e., research or educational use), and no modifications or adaptations are made. See: [https://creativecommons.org/licenses/by-nc-nd/4.0/](https://creativecommons.org/licenses/by-nc-nd/4.0/)

## References

1.  Norwegian Hip Fracture Register. Annual Report 2019: Norwegian National Advisory Unit on Arthroplasty and Hip Fractures. Bergen (Norway): Haukeland University Hospital; 2019:193–246.
    
    

2.  National Hip Fracture Database Annual Report 2019. London (UK): Royal College of Physicians; 2019. Available: [https://www.nhfd.co.uk/files/2019ReportFiles/NHFD\_2019\_Annual\_Report\_v101.pdf](https://www.nhfd.co.uk/files/2019ReportFiles/NHFD\_2019_Annual_Report_v101.pdf) (accessed 2020 July 12).
    
    

3.  Tiihonen R, Alaranta R, Helkamaa T, et al. A 10-year retrospective study of 490 hip fracture patients: reoperations, direct medical costs, and survival. Scand J Surg 2019;108:178–84.
    
    

4.  1.  Bhandari M, 
    2.  Einhorn TA, 
    3.  Guyatt G, 
    4.  et al
    
    HEALTH Investigators; Bhandari M, Einhorn TA, Guyatt G, et al. Total hip arthroplasty or hemiarthroplasty for hip fracture. N Engl J Med 2019;381:2199–208.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

5.  Robertson GA, Wood AM. Hip hemi-arthroplasty for neck of femur fracture: What is the current evidence? World J Orthop 2018;9:235–44.
    
    

6.  Moerman S, Mathijssen NMC, Niesten DD, et al. More complications in uncemented compared to cemented hemiarthroplasty for displaced femoral neck fractures: a randomized controlled trial of 201 patients, with one year follow-up [published erratum 2017;18:300]. BMC Musculoskelet Disord 2017;18:169.
    
    

7.  McGraw IWW, Spence SC, Baird EJ, et al. Incidence of periprosthetic fractures after hip hemiarthroplasty: Are uncemented prostheses unsafe? Injury 2013;44:1945–8.
    
    

8.  Veldman HD, Heyligers IC, Grimm B, et al. Cemented versus cementless hemiarthroplasty for a displaced fracture of the femoral neck: a systematic review and meta-analysis of current generation hip stems. Bone Joint J 2017;99-B:421–31.
    
    

9.  Okike K, Chan PH, Prentice HA, et al. Association between uncemented vs cemented hemiarthroplasty and revision surgery among patients with hip fracture. JAMA 2020;323:1077–84.
    
    

10. Cram P, Yan L, Bohm E, et al. Trends in operative and nonoperative hip fracture management 1990–2014: a longitudinal analysis of Manitoba administrative data. J Am Geriatr Soc 2017;65:27–34.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=27861712&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

11. Manitoba Physician’s Manual. Winnipeg: Government of Manitoba; 2021:F-11, F-17, F-19, F-20, F-23. Available: [https://www.gov.mb.ca/health/documents/physmanual.pdf](https://www.gov.mb.ca/health/documents/physmanual.pdf) (accessed 2021 May 20).
    
    

12. Zou G. A modified Poisson regression approach to prospective studies with binary data. Am J Epidemiol 2004;159:702–6.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1093/aje/kwh090&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=15033648&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 
    
    [Web of Science](http://canjsurg.ca/lookup/external-ref?access_num=000220484900009&link_type=ISI) 

13. Higgs GB, MacDonald DW, Gilbert JL, et al.Implant Research Center Writing Committee. Does taper size have an effect on taper damage in retrieved metal-on-polyethylene total hip devices? J Arthroplasty 2016;31(Suppl):277–81.
    
    

14. Australian Orthopaedic Association National Joint Replacement Registry. Hip, Knee & Shoulder Arthroplasty: 2019 annual report. Adelaide (AU): Australian Orthopaedic Association; 2019.
    
    

15. Grosso MJ, Danoff JR, Murtaugh TS, et al. Hemiarthroplasty for displaced femoral neck fractures in the elderly has a low conversion rate. J Arthroplasty 2017;32:150–4.
    
    

16. Rogmark C, Fenstad AM, Leonardsson O, et al. Posterior approach and uncemented stems increases the risk of reoperation after hemiarthroplasties in elderly hip fracture patients. Acta Orthop 2014;85:18–25.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.3109/17453674.2014.885356&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=24460108&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

17. Lee R, Lee D, Gowda NB, et al. Surgical complications associated with congestive heart failure in elderly patients following primary hip hemiarthroplasty for femoral neck fractures. Eur J Orthop Surg Traumatol 2019;29:1253–61.
    
    

18. Kumar P, Rajnish RK, Neradi D, et al. Hemiarthroplasty for neck of femur fractures: To cement or not? A systematic review of literature and meta-analysis. Eur J Orthop Surg Traumatol 2019;29:731–46.
    
    

19. Song JSA, Dillman D, Wilson D, et al. Higher periprosthetic fracture rate associated with use of modern uncemented stems compared to cemented stems in femoral neck fracture. Hip Int 2019;29:177–83.
    
    

20. Laflamme M, Angers M, Vachon J, et al. High incidence of intraoperative fractures with a specific cemented stem following intracapsular displaced hip fracture. J Arthroplasty 2020;35:485–9.
    
    

21. Tol MCJM, van Beers LWAH, Willigenburg NW, et al. Posterolateral or direct lateral approach for hemiarthroplasty after femoral neck fractures: a systematic review. Hip Int 2021;31:154–65.
    
    

22. Jameson SS, Jensen CD, Elson DW, et al. Cemented versus cementless hemiarthroplasty for intracapsular neck of femur fracture — a comparison of 60,848 matched patients using national data. Injury 2013;44:730–4.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1016/j.injury.2012.10.031&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=23206920&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

23. Spaans EA, Koenraadt KLM, Wagenmakers R, et al. Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases. Arch Orthop Trauma Surg 2019;139:255–61.
    
    

24. Horner NS, Grønhaug Larsen KM, Svantesson E, et al. Timing of hip hemiarthroplasty and the influence on prosthetic joint infection. PLoS One 2020;15:e0229947.
    
    

25. Gjertsen J-E, Fenstad AM, Leonardsson O, et al. Hemiarthroplasties after hip fractures in Norway and Sweden: a collaboration between the Norwegian and Swedish national registries. Hip Int 2014;24:223–30.
    
    

26. Kim S-J, Park H-S, Lee D-W, et al. Lower preoperative Hounsfield unit values are associated with intra-operative fractures in cementless bipolar hemiarthroplasty. Arch Osteoporos 2017;12:110.
    
    

27. Kouyoumdjian P, Dhenin A, Dupeyron A, et al. Periprosthetic fracture in the elderly with anatomic modular cementless hemiarthroplasty. Orthop Traumatol Surg Res 2016;102:701–5.
    
    

28. Phillips JRA, Moran CG, Manktelow ARJ. Periprosthetic fractures around hip hemiarthroplasty performed for hip fracture. Injury 2013;44:757–62.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1016/j.injury.2012.09.015&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=23103113&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

29. Yli-Kyyny T, Ojanperä J, Venesmaa P, et al. Perioperative complications after cemented or uncemented hemiarthroplasty in hip fracture patients. Scand J Surg 2013;102:124–8.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1177/1457496913482249&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=23820689&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

30. Grammatopoulos G, Wilson HA, Kendrick BJL, et al. Hemiarthroplasty using cemented or uncemented stems of proven design: a comparative study. Bone Joint J 2015;97-B:94–9.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=25568420&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

31. Nawaz SZ, Keightley AJ, Desai A, et al. Displaced intracapsular neck of femur fractures: outcome of 810 hydroxyapetite coated (HAC) uncemented hemiarthroplasties. Injury 2017;48:909–13.
    
    

32. Kristensen TB, Dybvik E, Kristoffersen M, et al. Cemented or uncemented hemiarthroplasty for femoral neck fracture? Data from the Norwegian Hip Fracture Register. Clin Orthop Relat Res 2020;478:90–100.
    
    

33. Gjertsen JE, Lie SA, Vinje T, et al. More re-operations after uncemented than cemented hemiarthroplasty used in the treatment of displaced fractures of the femoral neck: an observational study of 11,116 hemiarthroplasties from a national register. J Bone Joint Surg Br 2012;94:1113–9.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

34. Hip and knee replacements in Canada, 2017–2018: Canadian Joint Replacement Registry annual report. Ottawa: Canadian Institute for Health Information; 2019. Available: [https://secure.cihi.ca/free\_products/cjrr-annual-report-2019-en-web.pdf](https://secure.cihi.ca/free_products/cjrr-annual-report-2019-en-web.pdf) (accessed 2020 Aug. 12).
    
    

35. Odumala AO, Iqbal MR, Middleton RG. Failure of closed reduction after dislocation of Austin Moore hemiarthroplasty: an analysis of risk factors. A 6-year follow-up study. J Arthroplasty 2010;25:781–4.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=19604664&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

36. Li L, Ren J, Liu J, et al. What are the risk factors for dislocation of hip bipolar hemiarthroplasty through the anterolateral approach? A nested case-control study. Clin Orthop Relat Res 2016;474:2622–9.
    
    

37. Hongisto MT, Nuotio MS, Luukkaala T, et al. Lateral and posterior approaches in hemiarthroplasty. Scand J Surg 2018; 107:260–8.
    
    

38. Svenøy S, Westberg M, Figved W, et al. Posterior versus lateral approach for hemiarthroplasty after femoral neck fracture: early complications in a prospective cohort of 583 patients. Injury 2017;48:1565–9.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

39. Parker MJ. Lateral versus posterior approach for insertion of hemiarthroplasties for hip fractures: a randomised trial of 216 patients. Injury 2015;46:1023–7.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1016/j.injury.2015.02.020&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=25769196&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

40. Ninh CC, Sethi A, Hatahet M, et al. Hip dislocation after modular unipolar hemiarthroplasty. J Arthroplasty 2009;24:768–74.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1016/j.arth.2008.02.019&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=18555648&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 
    
    [Web of Science](http://canjsurg.ca/lookup/external-ref?access_num=000269404200017&link_type=ISI) 

41. Madanat R, Mäkinen TJ, Ovaska MT, et al. Dislocation of hip hemiarthroplasty following posterolateral surgical approach: a nested case-control study. Int Orthop 2012;36:935–40.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=21931967&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

42. Raut S, Parker MJ. Medium to long term follow up of a consecutive series of 604 Exeter Trauma Stem Hemiarthroplasties (ETS) for the treatment of displaced intracapsular femoral neck fractures. Injury 2016;47:721–4.
    
    

43. von Roth P, Abdel MP, Harmsen WS, et al. Cemented bipolar hemiarthroplasty provides definitive treatment for femoral neck fractures at 20 years and beyond. Clin Orthop Relat Res 2015;473:3595–9.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1007/s11999-015-4462-z&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=26186915&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

44. Hartman YAW, Karssemeijer EGA, van Diepen LAM, et al. Dementia patients are more sedentary and less physically active than age- and sex-matched cognitively healthy older adults. Dement Geriatr Cogn Disord 2018;46:81–9.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

45. Figved W, Svenøy S, Röhrl SM, et al. Higher cartilage wear in unipolar than bipolar hemiarthroplasties of the hip at 2 years: a randomized controlled radiostereometric study in 19 fit elderly patients with femoral neck fractures. Acta Orthop 2018;89:503–8.
    
    

46. Noailles T, Brulefert K, Chalopin A, et al. What are the risk factors for post-operative infection after hip hemiarthroplasty? Systematic review of literature. Int Orthop 2016;40:1843–8.
    
    

47. Guren E, Figved W, Frihagen F, et al. Prosthetic joint infection — a devastating complication of hemiarthroplasty for hip fracture. Acta Orthop 2017;88:383–9.
    
    

48. Cordero-Ampuero J, de Dios M. What are the risk factors for infection in hemiarthroplasties and total hip arthroplasties? Clin Orthop Relat Res 2010;468:3268–77.
    
    [CrossRef](http://canjsurg.ca/lookup/external-ref?access_num=10.1007/s11999-010-1411-8&link_type=DOI) 
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=20544319&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

49. Gallardo-Calero I, Larrainzar-Coghen T, Rodriguez-Pardo D, et al. Increased infection risk after hip hemiarthroplasty in institutionalized patients with proximal femur fracture. Injury 2016;47:872–6.
    
    

50. Harrison T, Robinson P, Cook A, et al. Factors affecting the incidence of deep wound infection after hip fracture surgery. J Bone Joint Surg Br 2012;94:237–40.
    
    

51. de Jong L, Klem TMAL, Kuijper TM, et al. Factors affecting the rate of surgical site infection in patients after hemiarthroplasty of the hip following a fracture of the neck of the femur. Bone Joint J 2017;99-B:1088–94.
    
    [PubMed](http://canjsurg.ca/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Fcjs%2F65%2F4%2FE519.atom) 

52. Spaans EA, Koenraadt KLM, Wagenmakers R, et al. Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases. Arch Orthop Trauma Surg 2019;139:255–61.
    
    

53. Lau ACK, Neo GH, Lee HC. Risk factors of surgical site infections in hip hemiarthroplasty: a single-institution experience over nine years. Singapore Med J 2014;55:535–8.
    
    

54. Sathyanarayana V, Patel MT, Raghavan S, et al. Simultaneous bilateral femur neck fracture in a young adult with chronic renal failure — a case report and review of literature. J Orthop Case Rep 2015;5:24–6.
    
    

55. Ravi B, Pincus D, Khan H, et al. Comparing complications and costs of total hip arthroplasty and hemiarthroplasty for femoral neck fractures: a propensity score-matched, population-based study. J Bone Joint Surg Am 2019;101:572–9.
    
    

56. Cree M, Yang Q, Scharfenberger A, et al. Variations in treatment of femoral neck fractures in Alberta. Can J Surg 2002;45:248–54.
    
    

57. Salem KMI, Shannak OA, Scammell BE, et al. Predictors and outcomes of treatment in hip hemiarthroplasty dislocation. Ann R Coll Surg Engl 2014;96:446–51.
    
    

58. Leer-Salvesen S, Engesæter LB, Dybvik E, et al. Does time from fracture to surgery affect mortality and intraoperative medical complications for hip fracture patients? An observational study of 73 557 patients reported to the Norwegian Hip Fracture Register. Bone Joint J 2019;101-B:1129–37.
    
    

59. Rahme E, Kahn SR, Dasgupta K, et al. Short-term mortality associated with failure to receive home care after hemiarthroplasty. CMAJ 2010;182:1421–6.
    
    [Abstract/FREE Full Text](http://canjsurg.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoiY21haiI7czo1OiJyZXNpZCI7czoxMToiMTgyLzEzLzE0MjEiO3M6NDoiYXRvbSI7czoxOToiL2Nqcy82NS80L0U1MTkuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

60. Laflamme GY, Rouleau DM, Leduc S, et al. The Timed Up and Go test is an early predictor of functional outcome after hemiarthroplasty for femoral neck fracture. J Bone Joint Surg Am 2012;94:1175–9.
    
    [Abstract/FREE Full Text](http://canjsurg.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NjoiamJqc2FtIjtzOjU6InJlc2lkIjtzOjEwOiI5NC8xMy8xMTc1IjtzOjQ6ImF0b20iO3M6MTk6Ii9janMvNjUvNC9FNTE5LmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==) 

61. Facts on aging: demographics. Winnipeg: University of Manitoba, Centre on Aging; 2016. Available: [https://umanitoba.ca/centres/aging/pubs/coa\_factsonaging\_demographic-popn\_facts.html](https://umanitoba.ca/centres/aging/pubs/coa_factsonaging_demographic-popn_facts.html) (accessed 2020 July 14).