Comparison of the POSSUM score and P-POSSUM score in patients with femoral neck fracture

O-POSSUM and P-POSSUM as predictors of morbidity and mortality in older patients after hip fracture surgery: a meta-analysis

BACKGROUND

The POSSUM model has been widely used to predict morbidity and mortality after general surgery. Modified versions known as O-POSSUM and P-POSSUM have been used extensively in orthopedic surgery, but their accuracy is unclear. This systematic review evaluated the predictive value of these models in older patients with hip fractures.

METHODS

This study was performed and reported based on the "Preferred reporting items for systematic reviews and meta-analyses" guidelines. PubMed, Cochrane, EMBASE, and Web of Science were comprehensively searched for relevant studies, whose methodological quality was evaluated according to the "Methodological index for non-randomized studies" scale. Revman 5 was used to calculate weighted ratios of observed to expected morbidity or mortality.

RESULTS

The meta-analysis included 10 studies, of which nine (2549 patients) assessed the ability of O-POSSUM to predict postoperative morbidity, nine (3649 patients) assessed the ability of O-POSSUM to predict postoperative mortality, and four (1794 patients) assessed the ability of P-POSSUM to predict postoperative mortality. The corresponding weighted ratios of observed to expected morbidity or mortality were 0.84 (95% CI 0.70-1.00), 0.68 (95% CI 0.49-0.95), and 0.61 (95% CI 0.16-2.38).

CONCLUSIONS

While O-POSSUM shows reasonable accuracy in predicting postoperative morbidity in older patients with hip fractures, both P-POSSUM and O-POSSUM substantially overestimate postoperative mortality. The POSSUM model should be optimized further for this patient population.

Inter-rater agreement in pPOSSUM scores of geriatric trauma patients: a prospective evaluation

PURPOSE

Risk prediction models are widely used in the perioperative setting to identify high-risk patients who may benefit from additional care and to aid clinical decision-making. pPOSSUM is such a prediction model, however, little is known about the inter-rater agreement when scoring subjective parameters. This study assessed the inter-rater agreement between clinicians of different specialties and work-level when scoring 30 clinical case reports of geriatric hip fracture patients with pPOSSUM.

METHODS

Eighteen clinicians of the department of Surgery (three specialists, four residents), Anaesthesiology (four specialists, two residents) and Emergency Medicine (three specialists, two residents) who were familiar with the pPOSSUM scoring system were asked to calculate the scores. The kappa statistic and the statistical method of Fleiss were used to analyse inter-rater agreement.

RESULTS

The response rate was 100%. Among surgeons, Anaesthesiologists and Emergency department doctors (ED), the overall mean kappa values were 0.42, 0.08 and 0.20, respectively. Among surgery, anaesthesiology and ED residents the overall mean kappa values were 0.21, 0.33 and 0.37, respectively. Within the department of Surgery, Anaesthesiology and Emergency Medicine the overall mean kappa values were 0.23, 0.12 and 0.22, respectively. An overall mean kappa value of 0.19 was seen among all specialists. All residents had an overall mean kappa value of 0.21 and all clinicians had an overall mean kappa value of 0.21.

CONCLUSION

The overall inter-rater agreement of clinicians and interdisciplinary agreement when scoring geriatric hip fracture patients with pPOSSUM was low and prone to subjectivity in our study. A higher work-experience level did not lead to better agreement. When pPOSSUM is calculated without clinical assessment by the same clinician, caution is advised to prevent over-reliance on the pPOSSUM risk prediction model.

LEVEL OF EVIDENCE

III.

Rapid preoperative predicting tools for 1-year mortality and walking ability of Asian elderly femoral neck fracture patients who planned for hip arthroplasty

BACKGROUND

Femoral neck fractures in elderly patients typically warrant operative treatment and are related to high risks of mortality and morbidity. As early hip arthroplasties for elderly femoral neck fractures are widely accepted, rapid predicting models that allowed quantitative and individualized prognosis assessments are strongly needed as references for orthopedic surgeons during preoperative conversations.

METHODS

Data of patients aged ≥ 65 years old who underwent primary unilateral hemiarthroplasty or total hip arthroplasty due to femoral neck fracture between January 1st, 2012 and June 30th, 2019 in our center were collected. Candidate variables included demographic data, comorbidities, and routine preoperative screening tests. The main outcomes included 1-year mortality and free walking rate after hip arthroplasty. Patients were randomly divided into derivation and validation groups in the ratio of three to one. Nomograms were developed based on multivariable logistic regressions of derivation group via R language. One thousand bootstraps were used for internal validation. Those models were further tested in the validation group for external validation.

RESULTS

The final analysis was performed on 702 patients after exclusion and follow-up. All-cause 1-year mortality of the entire data set was 23.4%, while the free walking rate was 57.3%. Preoperative walking ability showed the biggest impact on predicting 1-year mortality and walking ability. Static nomograms were created from the final multivariable models, which allowed simplified graphical computations for the risks of 1-year mortality and walking ability in a certain patient. The bias-corrected C index of those nomograms for predicting 1-year mortality in the derivation group and the validation group were 0.789 and 0.768, while they were 0.807 and 0.759 for predicting postoperative walking ability. The AUC of the mortality and walking ability predicting models were 0.791 and 0.818, respectively.

CONCLUSIONS

Our models enabled rapid preoperative 1-year mortality and walking ability predictions in Asian elderly femoral neck fracture patients who planned for hip arthroplasty, with adequate predictive discrimination and calibration. Those rapid assessment models could help surgeons in making more reasonable clinical decisions and subsequently reducing the risk of potential medical dispute via quantitative and individualized prognosis assessments.

The association between the Revised Cardiac Risk Index and short-term mortality after hip fracture surgery

PURPOSE

The post-operative mortality after hip fracture surgery is high and has remained largely unchanged during the last decades. The Revised Cardiac Risk Index (RCRI) is a tool used to evaluate the 30-day risk of, among other outcomes, post-operative mortality. The aim of this study is to determine the association between the RCRI score and post-operative mortality in patients undergoing hip fracture surgery.

METHODS

Data was obtained from the national hip fracture register which was cross-referenced with patients' electronic hospital records. All adults who underwent primary emergency hip fracture surgery in Orebro County, Sweden, between January 1, 2013 and December 31, 2017, were included. Patients were divided into two cohorts: low RCRI (score = 0-1) and high RCRI (score ≥ 2). A Poisson regression model was employed to investigate the association between a high RCRI score and 30- and 90-day post-operative mortality.

RESULTS

A total of 2443 patients, of whom 446 (18%) had a high RCRI score, were included in the current study. When adjusting for age, sex, comorbidities and type of surgery, the incidence of 30-day mortality increased by 46% in the high RCRI cohort (adj. IRR 1.46, 95% CI, 1.10-1.94, p = 0.010). Similar results were observed for 90-day mortality (adj. IRR 1.50, 95% CI, 1.21-1.84, p < 0.001).

CONCLUSION

The RCRI is applicable to patients that undergo surgery for traumatic hip fractures. A high RCRI score is associated with an increased incidence of both 30- and 90-day post-operative mortality. Future studies to evaluate these findings are needed.

Hip fracture mortality: Predictive models

The preoperative estimation of the risk of mortality after a hip fracture is very useful to plan time of surgery and perioperative care, inform patients and families about the prognosis and allows comparisons between different units. Different models have been developed to stratify mortality risk, but they show heterogeneity in terms of type of population and variables included, monitoring the time and statistical methods used, which makes it difficult to establish comparisons between them. The vast majority of them are awaiting external validation in populations different from those in which they were originally proposed. So far, the Nottingham Hip Fracture Score (NHFS) and the Orthopaedic Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (O-POSSUM) are the most commonly used models. The NHFS is simpler and faster to apply, and by not including intraoperative variables can be used at the time of admission.

Accuracy of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity score and the Nottingham risk score in hip fracture patients in Sweden - A prospective observational study

BACKGROUND

Little is known about accuracy of common risk prediction scores in elderly patients suffering from hip fractures. The objective of this study was to investigate accuracy of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) score, Portsmouth-POSSUM (P-POSSUM) score and the Nottingham Hip Fracture Score (NHFS) for prediction of mortality and morbidity in this patient group.

METHODS

This was a prospective single centre observational study on 997 patients suffering out-of-hospital cervical, trochanteric or subtrochanteric fracture of the neck of the femur. Calibration and discrimination was assessed by calculating the ratio of observed to expected events (O:E) and areas under receiver operating characteristics curves (ROC).

RESULTS

The 30-day mortality was 6.2% and complications, as defined by POSSUM, occurred in 41% of the patients. Overall O:E ratios for POSSUM, P-POSSUM and NHFS scores for 30-day mortality were 0.90, 0.98, and 0.79 respectively. The models underestimated mortality in the lower risk bands and overestimated mortality in the higher risk bands. In contrast, POSSUM predicted morbidity well with O:E ratios close to unity in most risk bands. The areas under the ROC curves for the scoring systems was 0.60-0.67.

CONCLUSION

The POSSUM score and NHFS show moderate calibration and poor discrimination in this cohort. The results suggest that mortality and morbidity in hip fracture patients are largely dependent on factors that are not included in these scores.

O-POSSUM score predicts morbidity and mortality in patients undergoing hip fracture surgery

PURPOSE

The aim of this study is to evaluate the O-POSSUM score capacity to predict the morbidity and mortality of patients undergoing hip fracture surgery.

MATERIAL AND METHODS

We retrospectively reviewed the clinical records of patients older than 65years old, operated on for hip fractures between January 2012 and December 2013. Of 229 patients, the mean age was 82.3years and 170 were women. We collected comorbidities, type of surgery, and expected morbidity and mortality O-POSSUM values.

RESULTS

After a minimum follow up of one year, 38 deaths were reported and 77 patients had complications. The expected mortality according to the O-POSSUM was 35 patients and expected morbidity 132.

CONCLUSION

By comparing the observed results with those predicted, the O-POSSUM scale is reliable in predicting mortality and overestimates morbidity.

Damage Control Orthopedics Management as Vital Procedure in Elderly Patients with Femoral Neck Fractures Complicated with Chronic Renal Failure: A Retrospective Cohort Study

Background

Chronic renal failure (CRF) predisposes to hip fractures in elderly patients, with high subsequent mortality. Selection and timing of the surgical procedure of such patients is a serious challenge. Many clinicians believe in earlier surgery as preferable and providing better outcomes. Damage control orthopedics (DCO) aids to adjust and optimize the overall condition of patients.

Methods

In 32 patients with femoral neck fractures complicated with CRF, we evaluated how the timing of the surgery determines the mortality rates if the DCO approach is applied. Preoperative ASA grading, POSSUM score, P-POSSUM score and DCO were carried out. Based on the assessment, timing of the surgery was ascertained.

Results

Of a total of 32 patients, twenty-nine patients were accepted for either early (< 48 hours; n = 18) or delayed (3–10 days; n = 10) surgery. Hip arthroplasty (total hip arthroplasty and hemiarthroplasty) was the principal surgery option. All patients survived operation and were followed up postoperatively with the average time of 30 days. Postoperative complications tended to occur at higher rates in the early vs. delayed surgery group (7/18 vs. 5/10). During follow up, a total of 3 patients died in both groups (2/18 in the early surgery and 1/10 in the delayed surgery group), mostly from multi-organ failures and acute respiratory distress syndrome. There was no significant difference in complication rates and Harris hip score between both groups.

Conclusion

In patients with femoral neck fracture complicated with CRF, delaying the surgery for several days does not increase the incidence of postoperative adverse events.

Risk scoring models for predicting peri-operative morbidity and mortality in people with fragility hip fractures: Qualitative systematic review

RATIONALE

Accurate peri-operative risk prediction is an essential element of clinical practice. Various risk stratification tools for assessing patients' risk of mortality or morbidity have been developed and applied in clinical practice over the years. This review aims to outline essential characteristics (predictive accuracy, objectivity, clinical utility) of currently available risk scoring tools for hip fracture patients.

METHODS

We searched eight databases; AMED, CINHAL, Clinical Trials.gov, Cochrane, DARE, EMBASE, MEDLINE and Web of Science for all relevant studies published until April 2015. We included published English language observational studies that considered the predictive accuracy of risk stratification tools for patients with fragility hip fracture.

RESULTS

After removal of duplicates, 15,620 studies were screened. Twenty-nine papers met the inclusion criteria, evaluating 25 risk stratification tools. Risk stratification tools considered in more than two studies were; ASA, CCI, E-PASS, NHFS and O-POSSUM. All tools were moderately accurate and validated in multiple studies; however there are some limitations to consider. The E-PASS and O-POSSUM are comprehensive but complex, and require intraoperative data making them a challenge for use on patient bedside. The ASA, CCI and NHFS are simple, easy and inexpensive using routinely available preoperative data. Contrary to the ASA and CCI which has subjective variables in addition to other limitations, the NHFS variables are all objective.

CONCLUSION

In the search for a simple and inexpensive, easy to calculate, objective and accurate tool, the NHFS may be the most appropriate of the currently available scores for hip fracture patients. However more studies need to be undertaken before it becomes a national hip fracture risk stratification or audit tool of choice.