Isolated rib fractures in elderly patients: mortality and morbidity
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* Yoav Barnea
* Hanoch Kashtan
* Yehuda Skornick
* Nahum Werbin

## Abstract

**Objectives:** To describe the management, morbidity and mortality seen with isolated rib fractures in elderly patients and assess the need for hospitalization.

**Design:** A case series.

**Setting:** A tertiary care centre in Tel Aviv.

**Methods:** Hospital records of 77 elderly patients (age 65 yr and older) admitted with isolated rib fractures were reviewed over a 9-year period.

**Main outcome measures:** Demographic, medical and hospitalization data, blood hemoglobin and oxygen saturation levels.

**Results:** The number of fractured ribs was found to correlate with the morbidity (*p* = 0.027) and mortality (*p* = 0.006). There were no significant differences in these rates with respect to comorbidity except for diabetes (higher morbidity) and congestive heart failure (higher mortality). Twenty-eight patients (36%) had pulmonary complications and 1 had cardiac complications. Pulmonary complications were fatal in 6 patients (7.8%). Multivariate analysis of the factors related to morbidity demonstrated that only oxygen saturation (*p* = 0.0009) and diabetes (*p* = 0.03) correlated significantly.

**Conclusions:** In spite of significant morbidity and mortality in elderly patients with isolated rib fractures, prediction of the prognosis for these patients is presently not possible. Admission for observation and treatment is therefore justified and beneficial.

Rib fracture is commonly seen in the emergency department. It is manifested in a wide variety of signs, symptoms, mechanism of injury and associated injuries. Rib fractures are usually a sign of a more severe injury, with high morbidity and mortality from associated injuries such as head, chest, abdomen and extremity trauma.1 Isolated rib fractures are defined as rib fractures with no associated injury, regardless of the number of fractured ribs. Such trauma is considered to be minor and treatable on an ambulatory basis with no need for hospital admission, especially in younger patients.2

Isolated rib fractures are one of the most common fractures among the elderly (about 12% of all fractures), with an increasing incidence recorded over the past 30 years.3 Studies have shown that although trauma affects principally the young, elderly persons are at risk of higher morbidity and mortality when similarly injured.4,5 For this reason, our policy is to admit for observation all elderly patients who present with isolated rib fractures.

The aim of this study is to document the incidence, morbidity and mortality of isolated rib fractures in the elderly and to assess the need for hospitalization.

## Patients and methods

We reviewed the hospital records of all patients admitted to our department of surgery with rib fractures and no associated injuries between January 1990 and December 1998. All rib fractures were confirmed radiologically.

Data on age, sex, mechanism of injury, number and location of rib fracture, length of hospital stay, complications, comorbidity and discharge disposition were retrieved. Blood hemoglobin and oxygen saturation (SaO2) levels that were measured on the patient’s arrival to the hospital were recorded. All patients were followed up for a minimum of 6 months after discharge.

### Statistical analysis

Discrete variables were compared using χ2 analysis. Continuous variables were compared using Student’s *t*-test. Analysis of multivariable parameters was performed using logistical regression. Differences were considered significant when the *p* value was less than 0.05.

## Results

During the study period 148 patients were admitted with isolated rib fractures. Of these, 77 (52%) were 65 years of age or older and had isolated rib fractures. There were 40 (52%) men and 37 (48%) women. The mean (and standard deviation) age was 79.9 (7.9) years (range 65–93 yr). The fractured ribs were on the left side in 39 (51%) patients, and no patient had a bilateral rib fracture.

The mechanism of injury is summarized in Table 1. The fractures were due to a fall from standing height or less in 69% of patients, to motor vehicle crashes in 14% of patients, and to miscellaneous causes such as assault, sports-related accidents and impact with moving objects in the rest. There was no correlation between the mechanism of injury and the morbidity and mortality.

View this table:
[Table 1](http://canjsurg.ca/content/45/1/43/T1)

Table 1 
Correlation Between the Mechanism of Injury and the Morbidity and Mortality of 77 Elderly Patients With Isolated Rib Fractures*

The average number of fractured ribs was 2.6 (range 1–6 ribs). The number of fractured ribs was found to correlate with the morbidity (*p* = 0.027) and mortality (*p* = 0.006) but not with the side of the fracture (Table 2).

View this table:
[Table 2](http://canjsurg.ca/content/45/1/43/T2)

Table 2 
Effect of the Number of Fractured Ribs on the Morbidity and Mortality In 77 Elderly Patients With Isolated Rib Fractures

Fifty-five patients (71%) had at least 1 concomitant disease (Table 3). Comorbidity had no effect on morbidity and mortality rates with 2 exceptions: the morbidity was significantly higher among diabetic than nondiabetic patients (*p* = 0.0095) and only patients with congestive heart failure had a significantly higher mortality (*p* = 0.001).

View this table:
[Table 3](http://canjsurg.ca/content/45/1/43/T3)

Table 3 
The Influence of Pre-trauma Comorbidity of the 77 Patients on Their Morbidity and Mortality After Rib Fracture

The mean (and SD) hospital stay was 4.5 (4.1) (range 1–33 d). Fortyeight patients (62%) had no complications during their hospitalization (Table 4). The mean (and SD) hemoglobin level on arrival to the hospital was 12.7 (1.3) g/L, and the mean SaO2 was 96% (3.5%).

View this table:
[Table 4](http://canjsurg.ca/content/45/1/43/T4)

Table 4 
Morbidity of 77 Elderly Patients With Isolated Rib Fractures in Relation to Risk Factors

Twenty-eight patients had pulmonary complications. Active cardiac ischemia developed in only 1 patient, who received appropriate treatment. The pulmonary complications are summarized in Table 4. Eight patients were admitted to the intensive care unit for treatment of their pulmonary complications. Low SaO2 was found to correlate with the morbidity of the study group (*p* = 0.002). Pulmonary complications were fatal in 6 patients (8%). Two patients died of respiratory failure and 4 patients died of pulmonary-induced sepsis. Five patients died during hospitalization and 1 patient died of pneumonia and sepsis 1 month after discharge.

No statistical correlation was found between the age or arrival hemoglobin level of the patients and morbidity. No statistical correlation was found between the age, hemoglobin level or SaO2 and mortality (data not shown).

Multivariate analysis of the factors related to morbidity demonstrated that only SaO2 level (*p* = 0.0009) and the presence of diabetes (*p* = 0.03) had significant correlation. Multivariate analysis of the mortality was statistically insignificant.

## Discussion

The results of this study demonstrate significant morbidity (38%) and mortality (8%) in elderly patients with isolated rib fractures. Although these patients had no associated injuries except for the fractured ribs, many suffered from complications and several died.

In their study on trauma in the elderly, Osler and colleagues4 stated that trauma is a different disease in the elderly from that in young people and that the elderly respond differently to their injuries. Elderly patients are more poorly endowed than younger ones in the anatomic (decreased muscle mass, thinned vertebral bodies, osteoporosis) and physiologic (low cardiopulmonary and immune system reserves) aspects related to rib fractures. These differences contribute to the higher overall morbidity and mortality in the elderly population.5 Younger patients (14–64 yr of age) with 1 or 2 fractured ribs with no associated injury have low morbidity and mortality and are best treated on an ambulatory basis with no need for hospital admission.1,2 However, elderly patients with 2 or fewer rib fractures with no associated injury demonstrated a morbidity of 24% in our study.

We attempted to find risk factors that might correlate with the morbidity and mortality. The importance of these correlations is the ability to predict the prognosis of elderly patients with isolated rib fractures and to identify the risk factors that predispose to morbidity. This study suggests that patients with multiple rib fractures, low SaO2 or the presence of diabetes have a higher morbidity and a poorer prognosis. The mortality was found to correlate with the number of fractured ribs and the presence of congestive heart failure, but this correlation was not found to be significant on the multivariate analysis. Other risk factors that predispose to morbidity and mortality in these patients are still unclear and warrant more research, especially since the clinical symptoms presented by these patients are not a good predictor of the prognosis.6 The finding that diabetic patients have a higher morbidity than nondiabetic patients could be explained by the basic immunocompromised state of the diabetic patients that results in more infections, slower healing rate and higher morbidity.

Because of this inability to adequately predict the prognosis of elderly patients with isolated rib fractures and in view of the significant morbidity and mortality that are involved, we find it justified and beneficial to admit these patients for observation and treatment. Nevertheless, it is imperative to conduct a prospective study on elderly patients with isolated rib fractures to look into other comorbid factors, for better prediction of the prognosis. Such a study could result in an admittance policy and guidelines for emergency department staff in these cases.

It is important for physicians to be aware of the special features of these injuries, not only to provide better care for elderly trauma patients but also to apply more aggressive measures of trauma resuscitation in these patients. Special attention should be given to high-risk patients with multiple rib fractures, low SaO2 or the presence of diabetes in light of their higher morbidity. Once admitted, these patients should receive stricter triage and treatment protocols that include aggressive pulmonary toilet, vigorous cardiac monitoring, careful fluid management and strong analgesic medication. 7 A high degree of awareness should be maintained throughout the hospitalization and any sign or symptom of pulmonary compromise should be dealt with expeditiously.

## Acknowledgements

We thank Esther Eshkol for editorial assistance.

*   Accepted January 10, 2001.

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