Abstract
Background
Neurological conditions such as Parkinson’s disease are commonly accepted as a risk factor for an increased likelihood of undergoing revision surgery or death after THA. However, the available evidence for an association between Parkinson’s disease and serious complications or poorer patient-reported outcomes after THA is limited and contradictory.
Questions/purposes
(1) Do patients with a preoperative diagnosis of Parkinson’s disease have an increased risk of death after elective THA compared with a matched control group of patients? (2) After matching for patient- and surgery-related factors, do revision rates differ between the patients with Parkinson’s disease and the matched control group? (3) Are there any differences in patient-reported outcome measures for patients with Parkinson’s disease compared with the matched control group?
Methods
Data were derived from a merged database with information from the Swedish Hip Arthroplasty Register and administrative health databases. We identified all patients with Parkinson’s disease who underwent THA for primary osteoarthritis between January 1, 1999 and December 31, 2012 (n = 490 after exclusion criteria applied). A control group was generated through exact one-to-one matching for age, sex, Charlson comorbidity index, surgical approach, and fixation method. Risk of death and revision were compared between the groups using Kaplan-Meier and log-rank testing. Patient-reported outcome measures (PROMs), routinely recorded as EQ-5D, EQ VAS, and pain VAS, were measured at the preoperative visit and at 1-year postoperatively; mean absolute values for PROM scores and change in scores over time were compared between the two groups.
Results
The risk of death did not differ at 90 days (control group risk = 0.61%; 95% CI = 0.00–1.3; Parkinson’s disease group risk = 0.62%; 95% CI = 0.00–1.31; p = 0.998) or 1 year (control group = 2.11%; 95% CI = 0.81–3.39; Parkinson’s disease group = 2.56%, 95% CI = 1.12–3.97; p = 0.670). At 9 years, the risk of death was increased for patients with Parkinson’s disease (control group = 28.05%; 95% CI = 22.29–33.38; Parkinson’s disease group = 54.35%; 95% CI = 46.72–60.88; p < 0.001). The risk of revision did not differ at 90 days (control group = 0.41%; 95% CI = 0.00–0.98; Parkinson’s disease group = 1.03%; 95% CI = 0.13–1.92; p = 0.256). At 1 year, the risk of revision was higher for patients with Parkinson’s disease (control group = 0.41%; 95% CI = 0.00–0.98; Parkinson’s disease group = 2.10%; 95% CIs = 0.80–3.38; p = 0.021). This difference was more pronounced at 9 years (control group = 1.75%; 95% CI = 0.11–3.36; Parkinson’s disease group = 5.44%; 95% CI = 2.89–7.91; p = 0.001) when using the Kaplan-Meier method. There was no difference between the control and Parkinson’s disease groups for level of pain relief at 1 year postoperatively (mean reduction in pain VAS score for control group = 48.85, SD = 20.46; Parkinson’s disease group = 47.18, SD = 23.96; p = 0.510). Mean change in scores for quality of life and overall health from preoperative measures to 1 year postoperatively were smaller for patients in the Parkinson’s disease group compared with controls (mean change in EQ-5D scores for control group = 0.42, SD = 0.32; Parkinson’s disease group = 0.30, SD = 0.37; p 0.003; mean change in EQ VAS scores for control group = 20.94, SD = 23.63; Parkinson’s disease = 15.04, SD = 23.00; p = 0.027).
Conclusions
Parkinson’s disease is associated with an increased revision risk but not with short-term mortality rates relevant to assessing risk versus benefit before undergoing THR. The traditional reluctance to perform THR in patients with Parkinson’s disease may be too conservative given that the higher long-term risk of death is more likely due to the progressive neurological disorder and not THR itself, and patients with Parkinson’s disease report comparable outcomes to controls. Further research on outcomes in THR for patients with other neurological conditions is needed to better address the broader assumptions underlying this traditional teaching.
Level of Evidence Level III, therapeutic study.
Introduction
Total hip replacement has been celebrated as the operation of the century [18] but is not without potentially serious complications, such as premature death, infection, instability and dislocation, periprosthetic fracture and implant loosening.
Parkinson’s disease is a relatively common neurodegenerative disorder (prevalence of 0.5% to 1% in those aged 60 to 69 years; prevalence increases further with age) [7, 24]. The associated disease features of neuromuscular dysfunction, cognitive impairment, and poor balance are suggested as potential explanations for the link between neurological Parkinson’s disease and worse postoperative outcomes [11, 22, 25, 27, 36]. However, there are contradictory findings regarding patients with Parkinson’s disease undergoing THA. A systematic review conducted in 2009 by Queally et al. [27] identified “only 13 studies which described the outcome” of THA in patients with neurological conditions, of which only two papers involved Parkinson’s disease [21, 35]. The largest of these studies used data from the Scottish National Arthroplasty Registry and found that there was no difference in dislocation rates after THA for patients with Parkinson’s disease (n = 1467) compared with the national average [21]. However, in 2014, a study by Jämsen et al. [14], using Finnish National Arthroplasty Registry data, observed that patients with Parkinson’s disease (n = 297) “had an approximately two-fold risk of hip dislocation” after THA with a particular increase in early dislocation compared with control subjects; there was no difference after the first postoperative year [14]. A more recent systematic review, studying patients with neuromuscular imbalance [15] (analyzing published evidence up to April 2017), did not identify any additional relevant evidence of altered outcomes in patients with Parkinson’s disease undergoing THA.
Neurological conditions are commonly accepted as a risk factor that increase the likelihood of undergoing revision surgery or death after THA, but the available evidence for the association between Parkinson’s disease and serious complications or poorer outcome scores after THA is limited and contradictory [11, 15, 21, 25, 27, 33, 35, 36]. It is therefore difficult to offer an accurate and relevant risk assessment before THA for patients with specific neurological conditions such as idiopathic Parkinson’s disease, a relatively common neurological condition [7].
We therefore asked: (1) Do patients with a preoperative diagnosis of Parkinson’s disease have an increased risk of death after elective THA when compared with a matched control group of patients? (2) After matching for patient- and surgery-related factors, do revision rates differ between the patients with Parkinson’s disease and the matched control group? (3) Are there any differences in patient-reported outcomes for patients with Parkinson’s disease compared with the matched control group?
Materials and Methods
This study was performed with a retrospective case-control design using data derived from longitudinally maintained and integrated data sets available through the Swedish Hip Arthroplasty Register (SHAR) (Fig. 1)[34].
Fig. 1.
The flowchart outlines the process of identifying patients who underwent THA with a preoperative diagnosis of Parkinson’s disease and the process of identifying appropriate one-to-one matched control patients.
All patients with a pre-existing diagnosis of Parkinson’s disease who underwent primary THA for the treatment of primary osteoarthritis (OA) in Sweden between January 1, 1999 and December 31, 2012 were identified (n = 490 after exclusion criteria were applied). Diagnoses of both primary OA and Parkinson’s disease were identified using the ICD-9 [3] and ICD-10 [37] codes (Table 1); ICD-9 and ICD-10 were both used because coding switched from ICD-9 to ICD-10 during the study period.
Table 1.
Relevant ICD-9 and ICD-10 codes
We excluded patients with alternative indications for THA such as secondary OA or fracture because those indications may be associated with an increased risk of postoperative complications [21, 22, 25, 27]. In this study, Parkinson’s disease refers to idiopathic Parkinson’s disease; therefore, we excluded patients with secondary or atypical Parkinsonian conditions. Patients with a diagnosis of stroke, Parkinson’s disease dementia, Alzheimer’s disease, or vascular dementia were also excluded because these are relatively common neurological conditions that are known to also potentially affect postoperative outcomes [13, 17, 21, 27]. None of the patients with Parkinson’s disease were listed as having Lewy body dementia in addition to Parkinson’s disease. From an initial unmatched pool of 122,212 patients, a control group of 490 was generated through exact one-to-one matching. Exact matching is a statistical technique, which results in equal distributions of treatment probabilities among cases and controls. Each patient with Parkinson’s disease (study group) was matched to exactly one patient without the diagnosis of Parkinson’ s disease (control group) with exactly the same age, sex, Charlson comorbidity index [4], surgical approach, and fixation method (Fig. 1). Where variables used in matching were not known for patients with Parkinson’s disease, these patients were excluded from the analysis. In seven instances, there was no available control patient with an exact match for age despite other variables matching; where this occurred, we selected a control patient aged as near as possible.
All patients in this study were followed until revision, death, or end of the study period. For participants in the control group, mean followup was 5.6 years (SD = 3.5); mean followup for patients with Parkinson’s disease was 4.7 years (SD = 3.2). Using linkage with the national, computerized population register, we are able to identify the exact dates of death for all Swedish residents because they have a unique identity number and death registration is mandatory. The deaths of most Swedish residents dying abroad are also registered. It is less likely however, that people with severe diseases decide to emigrate at old age, since many prefer the Swedish health care system. It is possible that people with Parkinson’s are even less likely to migrate, but we do not have any data on this, and we believe that the possible difference is inappreciable.
We used a one-way t-test for continuous variables and a chi-square test for categorical variables to perform group comparisons. We compared the risk of revision and death between the Parkinson’s disease group and the control group using Kaplan-Meier and log-rank testing at postoperative intervals of 90 days, 1 year and 9 years using percentages and 95% confidence intervals (CIs) with a p value < 0.05 regarded as statistically significant. We compared indications for revision and duration of hospital admission for the primary procedure between groups. PROMs were collected preoperatively and at 1 year postoperatively and were available for 74% (155 of 209) of the eligible study population and 83% (155 of 187) of the eligible control group. The PROMs program was introduced in Sweden in 2002 but national coverage was only reached in 2008; therefore, we decided to only use data from 2008. Specific PROMs analyzed include the EQ-5D and VAS for pain, and general health [5, 28-31]. PROMs were reported as absolute values as well as change between the preoperative and 1-year postoperative recordings. Statistical analysis was performed using R Statistical Software (R Foundation for Statistical Computing, Vienna, Austria).
Mean patient age was 73 years (SD 7.8 years) for each group, and each group had a one-to-one male-to-female ratio (Table 2). Most patients received cemented implants; relatively few patients received uncemented, hybrid, or reverse hybrid fixation.
Table 2.
Age, sex, and fixation method for control and Parkinson’s disease patient groups
Results
There was no difference in the risk of death between control and Parkinson’s disease groups in the 90-day (control group risk = 0.61%; 95% CI = 0.00–1.3; Parkinson’s disease group risk = 0.62%; 95% CI = 0.00–1.31; p = 0.998) and 1-year postoperative periods (control group = 2.11%; 95% CI = 0.81–3.39; Parkinson’s disease group = 2.56%; 95% CI = 1.12–3.97; p = 0.670) (Fig. 2). However, patients with Parkinson’s disease had a higher risk of death long-term in the 9-year postoperative period (control group = 28.05%; 95% CI = 22.29–33.38; Parkinson’s disease group = 54.35%; 95% CI = 46.72–60.88; p < 0.001) and when using the log-rank test (Table 3).
Fig. 2.
The graph shows Kaplan-Meier survival analysis for mortality as the endpoint for the patients with Parkinson’s disease and the patients in the control group with 95% CIs.
Table 3.
Risk of mortality over time for control group and Parkinson’s disease group patients
The Kaplan-Meier cumulative risk of undergoing revision surgery was similar between patients with Parkinson’s disease and control groups in the first 90 postoperative days (control group = 0.41%; 95% CI = 0.00–0.98; Parkinson’s disease group = 1.03%; 95% CI = 0.13–1.92; p = 0.256) (Fig. 3). However, patients with Parkinson’s disease were at higher risk of undergoing revision at 1 year (control group = 0.41%; 95% CI = 0.00–0.98; Parkinson’s disease group = 2.10%; 95% CI = 0.80–3.38; p = 0.021) and 9 years postoperatively (control group = 1.75%; 95% CI = 0.11–3.36; Parkinson’s disease group = 5.44%; 95% CI = 2.89–7.91; p = 0.001). We also observed this using the log-rank test (Table 4). Of the patients with Parkinson’s disease, 23 underwent revision and six patients in the control group underwent revision. There were various indications for revisions in both groups (Table 5).
Fig. 3.
The graph shows Kaplan-Meier survival analysis for revision as the endpoint for the patients with Parkinson’s disease and the patients in the control group with 95% CIs.
Table 4.
Risk of revision surgery over time for control group and Parkinson’s disease group patients
Table 5.
Indications for revision surgery for control and Parkinson’s disease patient groups
Preoperative absolute PROM scores were worse for the Parkinson’s disease group compared with controls for measures of health (mean EQ VAS scores for control group = 54.07, SD = 22.34; Parkinson’s disease group = 45.95, SD = 20.18; p = 0.001), health-related quality of life (mean EQ-5D scores for control group = 0.40, SD = 0.31; Parkinson’s disease group = 0.32, SD = 0.33; p = 0.036), and pain (mean pain VAS scores for control group = 62.44, SD = 15.97; Parkinson’s disease group = 65.81, SD = 13.55; p = 0.046) (Table 6). Absolute PROM scores were also lower for the Parkinson’s disease group at 1 year postoperative for health (mean EQ VAS scores for control group = 75.01, SD = 19.32; Parkinson’s disease group = 60.99, SD = 18.54; p < 0.001), health-related quality of life (mean EQ-5D scores for control group = 0.82, SD = 0.18; Parkinson’s disease group = 0.62, SD = 0.26; p < 0.001), and pain (mean pain VAS scores for control group = 13.59, SD = 15.53; Parkinson’s disease group = 18.63, SD = 20.57; p = 0.015). There was less improvement between preoperative scores and measures at 1 year postoperative for health (mean change in EQ VAS scores for control group = 20.94, SD = 23.63; Parkinson’s disease = 15.04, SD = 23.00; p = 0.027) and health-related quality of life (mean change in EQ-5D scores for control group = 0.42, SD = 0.32; Parkinson’s disease group = 0.30, SD = 0.37; p = 0.003) for patients with Parkinson’s disease compared with control patients. However, there was no difference in improvement in pain level, compared preoperatively to 1 year postoperatively and measured in pain VAS, between the two groups (mean change in pain VAS score for control group = -48.85, SD = 20.46; Parkinson’s disease group = -47.18, SD = 23.96; p = 0.510).
Table 6.
Comparison of mean absolute PROMs scores at preoperative and 1-year postoperative points and Delta change between scores for control and Parkinson’s disease groups
Discussion
A commonly held belief is that patients with neurological conditions are at greater risk of adverse outcomes after elective primary THA for primary OA compared with patients without these conditions. When looking at Parkinson’s disease in particular, however, there may be insufficient evidence to allow for an accurate and relevant understanding of the nature and extent of increased risk when undergoing an otherwise very effective procedure. To better understand this risk, this study examined death, revision risk, and PROM scores in a relatively large cohort of patients with Parkinson’s disease over a relatively long followup period. We found that patients with Parkinson’s disease did not have an increased risk of death or revision within the first 90 days and observed no difference in improvement in patient-reported pain scores after elective THA. There was, however, an increased risk of long-term death and revision.
This study has a number of limitations. First, like with other studies of elective procedures, patient selection bias may play a role in the outcomes we observed. Despite being a register study based on nationwide data collection, only 490 patients corresponding to the ICD codes were identified. This is unlikely to be due to a failure to detect cases because of incorrect ICD coding; the coding for Parkinson’s disease and related disorders has previously been examined in Sweden and found to be sufficiently accurate [9]. It seems reasonable that the patients with Parkinson’s disease who undergo THA are already the most active and “well” individuals in the larger Parkinson’s disease cohort and so are more likely to benefit from THA and to better tolerate the procedure. Because patients who are not considered for THA do not have relevant preoperative risk assessment measures and PROMs carried out, the data collection necessary to answer this question is outside the scope of this study. Although this limits the contribution of this study to the wider understanding of Parkinson’s disease, it is unlikely to limit generalizability in the context of assessing patients with Parkinson’s disease who present with primary OA and who might be appropriate to undergo primary THA.
Second, perhaps selection bias also plays a role in rates of revision surgery for patients with Parkinson’s disease. For example, it is possible that the decline in health associated with the progression of Parkinson’s disease over time means that patients who might otherwise undergo revision surgery are not well enough for a second procedure. This is an unknown that is difficult to fully account for because emergency department notes are not integrated into SHAR data sets; therefore, events such as dislocation are not as reliably recorded if managed conservatively compared with records for revision surgery. It could be argued that if patients experienced conservatively managed THA complications that would otherwise lead to revision, PROM scores would have been substantially worse than those observed. By including PROMs, we have attempted to reduce the effect of this limitation in the general conclusions drawn in the current study. However, the PROMs scores routinely collected in the SHAR are more generic, and disease-specific scores are not collected in our minimal data set. The PROMs program, which began in 2002, was only adopted nationwide in 2008, hence the limited number of patients returning both preoperative as well as postoperative PROMs questionnaires. Although there is an extremely limited loss of information from the registry with regard to recording of death, we are aware that the completeness for revisions is expected to be around 90%. The PROMs data for this study was available for 74% and 83% of the eligible patients in the study and control group, respectively.
Third, it is difficult to reliably control for comorbidities in the context of Parkinson’s disease using data derived from commonly used preoperative risk assessment tools (detection bias). The American Society of Anesthesiologists Physical Status Classification System scores have only been recorded nationally in Sweden since 2009 and so are not available for much of the observation period used in this study [1]. The SHAR-linked database also records Charlson and Elixhauser comorbidity index scores, but these also have issues [2, 4, 8, 10]. For example, the more consistently predictive Elixhauser comorbidity index assigns higher scores for patients with Parkinson’s disease and so using the score as a measure of health in generating a control group would likely require extensive review of hundreds of patient records to adapt the scores in this case [2, 23]. Previous research examining the link between other comorbidities and THA and TKA outcomes in patients with Parkinson’s disease found that cardiovascular disease and diabetes did affect long-term death but not the risk of revision [14]. Previously, research based on data recorded within the SHAR and linked databases has questioned the predictive effect of preoperatively recorded comorbidity on long-term death and PROMs after THA [2, 10].
Finally, additional surgical and implant factors are not accounted for. Although it may be desirable to address the factors recognized as important in the context of post-THA outcomes such as femoral stem offset, acetabular version, as well as soft tissue repair and tensioning [22, 25, 27, 34, 36], data for these variables are not routinely available through the SHAR; obtaining this information was beyond the scope of this project. This should not affect the interpretation of our results because no recommendations regarding specific procedural or implant choices are offered in this study.
The operation does not appear to result in an increased risk of early death (90 days, 1 year) in patients with Parkinson’s disease. These findings are of practical relevance in assessing the risk-versus-benefit ratio of elective primary THA. The risk of death over the long term, however, was increased in patients with Parkinson’s disease compared with control subjects. However, research on patients with Parkinson’s disease, as is also the case in patients with other serious chronic diseases, suggests that developing the condition does affect life expectancy and anticipated age at death, but this relationship is modulated by other factors such as age at diagnosis [12].
Therefore, it is difficult to speculate about how much of the increased risk of death in patients with Parkinson’s disease is the result of the disease itself and related comorbidities rather than undergoing THA. However, given that THA may have a positive correlation with life expectancy in some cohorts [6, 19, 32], it does not seem likely that this increased risk of death over the longer term could be attributed to the sequelae of THA, when this increased risk is not reflected in the short-term in our study.
In this study, patients with Parkinson’s disease had an overall higher risk of revision surgery when compared with control subjects. Early revision was more likely, which supports a link between neurological comorbidities and increased instability leading to revisions as supported by previous observations of an increase in early revisions in patients with neurological comorbidity [25, 27]. Patients with Parkinson’s disease in our study had an increased risk of revision for dislocation. This is compatible with existing reports, which frames the increased risk of revision for recurrent dislocation as a key mechanism linking neurological conditions and an increased risk of instability [27, 36]. However, these figures contrast with the study of patients with Parkinson’s disease in the Finnish registry data sets by Jämsen et al. [14], who found no difference in indication for revision compared with control subjects. Analysis of cumulative data from six national joint registries found that THA revision occurred in approximately 6.5% of cases at 5 years, doubling to 13% after 10 years [16]. The most common indications for revision include aseptic loosening (15%–82%), infection (7%–16%), instability (2%–23%), component failure (2%–10%), periprosthetic fracture (2%–6%), and pain (8%) [16, 17, 20, 26]. Estimates for the relative frequency of each indication vary greatly between studies. Given that only six (1%) of the 490 control patients and 23 (5%) of patients with Parkinson’s disease in this study underwent revision surgery over the full 14-year period, further research into the association between indication for revision and Parkinson’s disease is needed to meaningfully expand on this possible link.
Although patients with Parkinson’s disease had relatively poorer patient-reported outcomes for health and associated quality of life, this should be understood as a relative term; “poorer patient-reported outcomes” than achieved by the average patient may still provide life-changing benefits, with advantages that still outweigh the risk for such an effective procedure as THA. This supports the position that primary THA may be appropriate for patients with particular neurological conditions if these additional risks are taken into account during the discussion with patients [15].
Our results demonstrate that, while patients with Parkinson’s disease have no increased risk of revision surgery within the first 90 days, they are at an increased risk of revision surgery from 1 year postoperatively. There was no increase in risk of death in the short-term perioperative period or at 1 year after surgery. Although we recorded worse postoperative patient-reported outcomes than a carefully matched control group, the improvement in pain levels after surgery were not different between the groups. The traditional reluctance to perform THA in patients with Parkinson’s disease may not be warranted given that the higher long-term risk of death is likely due to the progressive neurological disorder and not THA itself. Further research on outcomes in THA for patients with Parkinson’s disease and likely other neurological conditions is needed to better address the broader assumptions underlying this traditional teaching and perhaps harness newer techniques and technology to reduce the revision risk.
Acknowledgments
We thank the Swedish orthopaedic teams and the register coordinators for their ongoing assistance with data collection.
Footnotes
One of the authors (MM) reports grants from Zimmer Biomet (Warsaw, IN, USA), personal fees from Zimmer Biomet, and grants from Link Sweden, outside the submitted work.
All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request.
Each author certifies that his or her institution approved the human protocol for this investigation and that all investigations were conducted in conformity with ethical principles of research.
This work was performed at the Swedish Hip Arthroplasty Register, Register Centrum Västra Götaland, Gothenburg, Sweden and the Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
References
- 1.American Society of American Society of Anesthesiologists - ASA Physical Status Classification System 2014. Available at: https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system. Accessed October 20, 2017.
- 2.Bülow E, Rolfson O, Cnudde P, Rogmark C, Garellick G, Nemes S. Comorbidity does not predict long-term mortality after total hip arthroplasty. Acta Orthopaedica. 2017;88:472-477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.CDC. ICD - ICD-9 - International Classification of Diseases, Ninth Revision https://www.cdc.gov/nchs/icd/icd9.htm. Accessed October 1, 2017. [PubMed]
- 4.Charlson ME, Pompei P, Ales KL, MacKenzie R. A new method of classifying prognostic in longitudinal studies: development and validation. J Chronic Dis. 1987;40:373-383. [DOI] [PubMed] [Google Scholar]
- 5.Cnudde P, Nemes S, Mohaddes M, Timperley J, Garellick G, Burström K, Rolfson O. Is preoperative patient-reported health status associated with mortality after total hip replacement? Int J Environ Res Public Health. 2017;14:pii E899. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Cnudde P, Rolfson O, Timperley AJ, Garland A, Kärrholm J, Garellick G, Nemes S. Do patients live longer after THA and is the relative survival diagnosis-specific? Clin Orthop Relat Res. 2018;476:1166-1175. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.de Lau LML, Breteler MMB. Epidemiology of Parkinson's disease. Lancet Neurol. 2006;5:525-535. [DOI] [PubMed] [Google Scholar]
- 8.Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for use with administrative data. Med Care. 1998;36:8-27. [DOI] [PubMed] [Google Scholar]
- 9.Feldman AL, Johansson AL, Gatz M, Flensburg M, Petzinger GM, Widner H, Lew MF, Pedersen NL, Wirdefeldt K. Accuracy and sensitivity of Parkinsonian disorder diagnoses in two Swedish national health registers. Neuroepidemiology. 2012;38:186-193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Greene ME, Rolfson O, Gordon M, Garellick G, Nemes S. Standard comorbidity measures do not predict patient-reported outcomes 1 year after total hip arthroplasty. Clin Orthop Relat Res. 2015;473:3370-3379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Hernigou P, Filippini P, Flouzat-Lachaniette CH, Batista SU, Poignard A. Constrained liner in neurologic or cognitively impaired patients undergoing primary THA. Clin Orthop Relat Res. 2010;468:3255-3262. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Ishihara LS, Cheesbrough A, Brayne C, Schrag A. Estimated life expectancy of Parkinson's patients compared with the UK population. J Neurol Neurosurg Psychiatry. 2007;78:1304-1309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Jämsen E, Peltola M, Puolakka T, Eskelinen A, Lehto MUK. Surgical outcomes of hip and knee arthroplasties for primary osteoarthritis in patients with Alzheimer's disease: A nationwide registry-based case-controlled study. Bone Joint J. 2015;97-B:654-661. [DOI] [PubMed] [Google Scholar]
- 14.Jämsen E, Puolakka T, Peltola M, Eskelinen A, Lehto MUK. Surgical outcomes of primary hip and knee replacements in patients with Parkinson's disease: a nationwide registry-based case-controlled study. Bone Joint J. 2014;96-B:486-491. [DOI] [PubMed] [Google Scholar]
- 15.Konan S, Duncan CP. Total hip arthroplasty in patients with neuromuscular imbalance. Bone Joint J. 2018;100-B(1 Suppl A):17-21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Labek G, Thaler M, Janda W, Agreiter M, Stockl B. Revision rates after total joint replacement: cumulative results from worldwide joint register datasets. J Bone Joint Surg Br. 2011;93:293-297. [DOI] [PubMed] [Google Scholar]
- 17.Lachiewicz PF, Soileau ES. Changing indications for revision total hip arthroplasty. J Surg Orthop Adv. 2005;14:82-84. [PubMed] [Google Scholar]
- 18.Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet. 2007;370:1508-1519. [DOI] [PubMed] [Google Scholar]
- 19.Lie SA, Engesæter LB, Havelin LI, Gjessing HK, Vollset SE. Mortality after total hip replacement: 0-10-Year follow-up of 39,543 patients in the Norwegian Arthroplasty Register. Acta Orthopaedica. 2000;71:19-27. [DOI] [PubMed] [Google Scholar]
- 20.Manach YL, Collins G, Bhandari M, Bessissow A, Boddaert J, Khiami F, Chaudhry H, De Beer J, Riou B, Landais P, Winemaker M, Boudemaghe T, Devereaux PJ. Outcomes after hip fracture surgery compared with elective total hip replacement. JAMA. 2015;314:1159-1166. [DOI] [PubMed] [Google Scholar]
- 21.Meek RMD, Allan DB, McPhillips G, Kerr L, Howie CR. Epidemiology of dislocation after total hip arthroplasty. Clin Orthop Relat Res. 2006;447:9-18. [DOI] [PubMed] [Google Scholar]
- 22.Meek RMD, Allan DB, McPhillips G, Kerr L, Howie CR. Late dislocation after total hip arthroplasty. Clin Med Res. 2008;6:17-23. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Menendez ME, Neuhaus V, Van Dijk CN, Ring D. The Elixhauser comorbidity method outperforms the Charlson index in predicting inpatient death after orthopaedic surgery. Clin Orthop Relat Res. 2014;472:2878-2886. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Nussbaum RL, Ellis CE. Alzheimer's disease and Parkinson's disease. N Engl J Med. 2003;348:1356-1364. [DOI] [PubMed] [Google Scholar]
- 25.Padgett DE, Warashina H. The unstable total hip replacement. Clin Orthop Relat Res. 2004:72-79. [DOI] [PubMed] [Google Scholar]
- 26.Prokopetz JJZ, Losina E, Bliss RL, Wright J, Baron JA, Katz JN. Risk factors for revision of primary total hip arthroplasty: a systematic review. BMC Musculoskelet Disord. 2012;13:251-251. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Queally JM, Abdulkarim a, Mulhall KJ. Total hip replacement in patients with neurological conditions. J Bone Joint Surg Br. 2009;91:1267-1273. [DOI] [PubMed] [Google Scholar]
- 28.Rabin R, Gudex C, Selai C, Herdman M. From translation to version management: A history and review of methods for the cultural adaptation of the euroqol five-dimensional questionnaire. Value Health. 2014;17:70-76. [DOI] [PubMed] [Google Scholar]
- 29.Rolfson O, Eresian Chenok K, Bohm E, Lubbeke A, Denissen G, Dunn J, Lyman S, Franklin P, Dunbar M, Overgaard S, Garellick G, Dawson J, Patient-reported outcome measures working group of the International Society of Arthroplasty R. Patient-reported outcome measures in arthroplasty registries. Acta Orthopaedica. 2016;(87 Suppl1):3-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Rolfson O, Karrholm J, Dahlberg LE, Garellick G. Patient-reported outcomes in the Swedish Hip Arthroplasty Register: results of a nationwide prospective observational study. J Bone Joint Surg Br. 2011;93B:867-875. [DOI] [PubMed] [Google Scholar]
- 31.Rolfson O, Malchau H. The use of patient-reported outcomes after routine arthroplasty: beyond the whys and ifs. Bone Joint J. 2015;97-B:578-581. [DOI] [PubMed] [Google Scholar]
- 32.Schwartsmann CR, Spinelli LdF, Boschin LC, Yépez AK, Crestani MV, Silva MF. Correlation between patient age at total hip replacement surgery and life expectancy. Acta Ortop Bras. 2015;23:323-325. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 33.Soong M, Rubash HE, Macaulay W. Dislocation after total hip arthroplasty. J Am Acad Orthop Surg. 2004;12:314-321. [DOI] [PubMed] [Google Scholar]
- 34.Swedish Hip Arthroplasty Register https://shpr.registercentrum.se/shar-in-english/the-swedish-hip-arthroplasty-register/p/ryouZwaoe. Accessed December 22, 2018.
- 35.Weber M, Cabanela ME, Sim FH, Frassica FJ, Harmsen SW. Total hip replacement in patients with Parkinson's disease. Int Orthop. 2002;26:66-68. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Werner BC, Brown TE. Instability after total hip arthroplasty. World J Orthop. 2012;3:122-130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 37.World Health Organisation. ICD-10 Version: 2016. Available at: https://icd.who.int/browse10/2016/en. Accessed October 1, 2017.