Surgical stabilization of rib fractures improves survival in functionally dependent trauma patients

Abstract

Background

Rib fractures are frequently encountered in trauma care and are particularly hazardous for functionally dependent patients, leading to increased morbidity and mortality rates. Surgical stabilization of rib fractures (SSRF) improves outcomes in selected populations; however, its role in functionally dependent individuals remains underexplored.

Methods

A retrospective cohort analysis was conducted using the American College of Surgeons-Trauma Quality Improvement Program dataset from 2020 to 2022. Patients with three or more rib fractures and AIS (Abbreviated Injury Scale) greater than 3 for the rib and thoracic wall, along with documented functional dependency, were included. Propensity score matching (3:1) was applied to reduce the selection bias between patients receiving SSRF and those managed conservatively. The main outcomes of interest were in-hospital mortality, acute respiratory distress syndrome, unplanned intensive care unit (ICU) admission, unplanned intubation, and ventilator-associated pneumonia (VAP). A subgroup analysis compared early (≤ 72 h) versus late SSRF.

Results

Among 18,643 eligible patients, 359 (1.9%) underwent SSRF. Before matching, patients with SSRF had higher Injury Severity Scores (ISS), ICU admissions, and complication rates. After matching (294 SSRF vs. 883 conservative patients), SSRF was associated with significantly lower mortality (4.8% vs. 8.7%, p = 0.038) despite higher rates of unplanned ICU admission (11.2% vs. 7.0%, p = 0.031), unplanned intubation (10.2% vs. 6.1%, p = 0.026), and VAP (3.1% vs. 0.6%, p = 0.002). In the subgroup analysis, early SSRF led to fewer ventilator days (p = 0.013), and shorter ICU (p < 0.001), and hospital length of stays (LOS, p < 0.001), with no difference in mortality compared with late SSRF. However, the late SSRF group still had significantly lower in-hospital mortality compared to the conservative treatment group (3.8% vs. 10.9%, p = 0.023).

Conclusion

SSRF in functionally dependent trauma patients with multiple rib fractures and significant chest wall injury (AIS ≥ 3) is associated with a significant reduction in in-hospital mortality compared to conservative management, despite a higher incidence of complications and prolonged ICU LOS. Early SSRF further improves clinical outcomes by decreasing ventilator duration and overall hospital LOS. These findings support the consideration of SSRF—particularly when performed early—as a beneficial strategy for managing rib fractures in functionally dependent patients. Even when performed at a later stage, SSRF still offers advantages over conservative treatment in reducing mortality. prospective studies are warranted to validate these results and establish clear patient selection criteria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13017-025-00634-2.

Background

Rib fractures are common injuries in cases of multiple trauma, particularly among elderly and functionally dependent patients, and are associated with significant morbidity and mortality [1–3]. These fractures can cause severe pain, impaired ventilation, and increased risk of pneumonia or respiratory failure, especially in patients with pre-existing comorbidities [4, 5]. Traditional management primarily involves pain control and supportive care; however, conservative treatment may be inadequate for frail individuals. Studies have shown that in patients over 65 years old with rib fractures, conservative management is associated with mortality rates of up to 20% and complication rates as high as 30% [6–8].

In recent years, surgical stabilization of rib fractures (SSRF) has gained attention as a method for stabilizing fractured ribs, improving pulmonary mechanics, and reducing complications [9]. Several studies have demonstrated that SSRF can shorten hospital length of stays (LOS), reduce ventilator dependence, and improve long-term functional outcomes [10–12]. Current consensus guidelines recommend SSRF for all patients with flail chest injuries. Beyond flail chest, SSRF should also be considered in non-flail chest patients with multiple (≥ 3) ipsilateral severely displaced rib fractures, or in those with ribs 3–10 fractures accompanied by respiratory failure despite mechanical ventilation, or pulmonary derangements in non-ventilated patients despite adequate analgesia. Additional indications include chest wall deformities affecting lung function, flail segments with displacement (particularly antero-lateral), and severe pain unresponsive to conservative treatment. SSRF should ideally be performed in specialized centers with multidisciplinary teams and standardized care protocols to ensure optimal outcomes [13]. Most existing research and clinical guidelines have focused on younger or physically independent populations, leaving the benefits of SSRF in functionally dependent patients largely unexplored.

Functionally dependent patients are individuals who require assistance from another person or a device to perform basic activities of daily living, such as bathing, feeding, dressing, toileting, and walking. This dependency may result from various conditions, including neurological disorders (e.g., stroke, dementia), musculoskeletal issues (e.g., fractures, arthritis), chronic illnesses (e.g., heart failure, chronic obstructive pulmonary disease [COPD]), or postoperative recovery [14–16]. Owing to limited physiological reserves, these patients are at increased risk of complications following rib fractures. According to the literature, at least one-third of patients develop pulmonary complications after rib fractures, including acute respiratory distress syndrome (ARDS), pulmonary embolism, and ventilator-associated pneumonia (VAP) [17, 18].

Given the potential of SSRF to enhance chest wall stability and respiratory function, investigating whether it reduces mortality and long-term disability in functionally dependent patients is essential. This study addresses that gap by comparing outcomes between functionally dependent patients who underwent SSRF and those who received conservative treatment. We hypothesized that SSRF would lead to improved survival and better clinical outcomes compared to non-surgical management. To test this, we conducted a retrospective cohort analysis comparing mortality, pulmonary complications, and hospital course between patients who underwent SSRF and those managed conservatively.

Methods

Study population

This retrospective cohort study utilized the ACS-TQIP dataset from 2020 to 2022. Owing to its retrospective design, a pre-study sample size calculation was not applicable. The diagnosis and severity of injuries were determined using Abbreviated Injury Scale (AIS) diagnostic codes. The AIS codes used by the ACS-TQIP included versions from 1998, 2005, and 2015, with the 2005 version used for the majority of patients (2020 ACS-TQIP: 99.45% of patients and 99.47% of diagnoses; 2021 ACS-TQIP: 95.53% of patients and 95.64% of diagnoses; 2022 ACS-TQIP: 91.86% of patients and 92.12% of diagnoses). The ACS-TQIP also provides a conversion table to map 2015 diagnoses to the 2005 version. Consequently, we excluded patients with AIS diagnosis codes from 1998 and converted all diagnosis codes from the 2015 version to the 2005 version. AIS code 9, indicating “not possible to assign,” was treated as a missing value.

After confirming the versions of the diagnosis codes, we included all patients with three or more rib fractures and AIS ≧ 3 for the rib and thoracic wall (Supplementary Table 1), along with documented functional dependency. The AIS has been shown to correlate well with ventilatory failure, a key indication for surgical intervention [19]. Exclusion criteria included the following: (1) severe head injury (AIS ≥ 4) or injury severity “not possible to assign” (AIS = 9; Supplementary Table 2); (2) non-binary or unknown gender (3); age under 18 years or unknown (4); trauma mechanisms other than blunt trauma or unknown mechanisms; (5) data not from ACS verification level I, II, or III facilities or unknown the facility level; (6) prehospital cardiac arrest or unknown status; (7) transfer to another hospital from the emergency department (ED) or lack of discharge information; (8) death in the ED; and (9) in-hospital death within 24 h or unknown LOS. (Fig. 1)

Fig. 1.

Patient enrollment procedure. ACS-TQIP American College of Surgeons-Trauma Quality Improvement Program, AIS Abbreviated Injury Scale, ED emergency department, ICH intracranial hemorrhage, SSRF surgical stabilization of rib fractures

The main outcomes of interest in this study included mortality and the incidence of ARDS, unplanned intensive care unit (ICU) admission, unplanned intubation, and VAP. Secondary outcomes included total ventilator days, whether intubation was performed, total ICU LOS, whether the patient was admitted to the ICU, and overall hospital LOS. The follow-up period was limited to the index hospitalization. Discharge dispositions labeled as “not known/not recorded” were treated as missing values, whereas “mortality” and “transfer to hospice” were categorized as mortality, following practical guidance for the National Trauma Data Bank [20].

Covariate selection

Covariate selection included patient demographics such as age, sex, and whether they underwent SSRF (Supplementary Table 3). Data on patients’ vital signs and consciousness in the ED were collected, including systolic blood pressure, body temperature, pulse rate, respiratory rate, pulse oximetry, and Glasgow Coma Scale score. Injury-related data, such as Injury Severity Score (ISS), cause of injury, and ACS facility level, were also recorded. Early SSRF was defined as surgery performed within 72 h of hospital admission, whereas SSRF performed after 72 h was considered late.

Relevant injuries included internal organ injuries of the head (Supplementary Table 2); thoracic injuries (4XXXXX), excluding superficial ones such as skin, subcutaneous tissue, pectoral muscle, and breast (Supplementary Table 4), and also excluding patients with three or more rib fractures and an AIS ≥ 3 for the rib and thoracic wall; and abdominal injuries (5XXXXX), excluding superficial ones such as skin, subcutaneous tissue, rectus abdominis, and vulva (Supplementary Table 5).

Comorbidities included congestive heart failure, current smoking, chronic renal failure, cerebrovascular accidents, diabetes mellitus, hypertension, COPD, liver cirrhosis, and myocardial infarction. The primary and secondary outcomes were collected as described above (see Study population).

Statistical analyses

Statistical analyses were conducted by reporting continuous variables as medians with interquartile ranges, whereas categorical variables were presented as counts and percentages. The Mann–Whitney U test was used to compare continuous variables, and categorical variables were analyzed using the chi-square test with continuity correction. When expected values under the null hypothesis were less than five, Fisher’s exact test was used instead of the chi-square test. An initial comparison of variables between patients who underwent rib fixation surgery and those who did not revealed several significant differences in pre-treatment factors. To minimize potential bias, a 3:1 propensity score matching (PSM) approach was applied to balance these pretreatment factors. A standardized mean difference > 0.1 was considered statistically significant. Following PSM, all target outcomes were compared. Additionally, a subgroup analysis was conducted to assess whether the timing of intervention affected outcomes. Statistical significance was defined as a P-value < 0.05, and all analyses were performed using R (version 2024.12.0 + 467).

Results

Table 1 lists the demographic characteristics of the patients. A total of 18,643 patients with rib fractures were included in this study, of whom 359 (1.9%) underwent SSRF, whereas 18,284 (98.1%) received conservative treatment. The SSRF group was significantly younger than the conservative treatment group (median age: 73.0 vs. 78.0 years, p < 0.001), and had a higher proportion of males (54.6% vs. 48.4%, p = 0.023). Patients in the SSRF group also presented with a higher respiratory rate (median: 20.0 vs. 18.0 breaths/min, p < 0.001), lower pulse oximetry (median: 96.0% [93.0, 98.0] vs. 96.0% [94.0, 98.0], p < 0.001), and higher ISS (median: 14.0 vs. 10.0, p < 0.001) compared to those receiving conservative treatment. Fall were notably less frequent in the conservative treatment group (64.1% vs. 82.7%, p < 0.001). Although most comorbidities were comparable between the two groups, current smoking (p < 0.001) and COPD (p = 0.048) were significantly more prevalent in the SSRF group. The median time to surgery among patients receiving SSRF was 67.2 h (interquartile range: 41.3–108.4). Compared to the conservative group, the SSRF group had higher ICU admission rates (76.6% vs. 42.5%, p < 0.001), greater ventilator use (34.3% vs. 7.3%, p < 0.001), longer ICU LOS (median: 5.0 vs. 0.0 days, p < 0.001), and extended total hospital LOS (median: 13.0 vs. 6.0 days, p < 0.001). They also experienced significantly higher rates of complications, including ARDS (2.2% vs. 0.3%, p < 0.001), unplanned ICU admissions (12.6% vs. 4.6%, p < 0.001), unplanned intubations (10.9% vs. 3.0%, p < 0.001), and VAP (3.4% vs. 0.3%, p < 0.001). Despite these indicators of more severe illness and resource utilization, mortality rates were not significantly different between the two groups (6.1% vs. 7.4%, p = 0.410).

Table 1.

Characteristics of all patients with rib fractures and received either SSRF or conservative treatments

	Conservative treatment (n = 18,284)		SSRF (n = 359)		P Value
Age (years)	78.0	[70.0, 84.0]	73.0	[65.5, 81.0]	< 0.001a*
Sex					0.023b*
Male	8848	(48.4)	196	(54.6)
Female	9436	(51.6)	163	(45.4)
Systolic blood pressure (mmHg)	141.0	[123.0, 160.0]	138.0	[122.0, 160.0]	0.129a
Body temperature (degree)	36.7	[36.4, 36.9]	36.7	[36.4, 36.9]	0.262a
Pulse rate (/min)	82.0	[71.0, 95.0]	88.0	[76.0, 101.0]	< 0.001a*
Respiratory rate (/min)	18.0	[16.0, 20.0]	20.0	[18.0, 22.8]	< 0.001a*
Pulse oximetry (%)	96.0	[94.0, 98.0]	96.0	[93.0, 98.0]	< 0.001a*
Glasgow Coma Scale score	15.0	[15.0, 15.0]	15.0	[15.0, 15.0]	0.599a
Injury Severity Score	10.0	[9.0, 14.0]	14.0	[10.0, 20.0]	< 0.001a*
Internal organ injuries of the head					0.814b
Nil	17,151	(93.8)	336	(93.6)
AIS = 2	470	(2.6)	11	(3.1)
AIS = 3	663	(3.6)	12	(3.3)
Thoracic injuries except rib and thoracic wall AIS ≥ 3					< 0.001b*
Nil	11,581	(63.4)	43	(12.0)
AIS = 1	6277	(34.4)	280	(78.4)
AIS = 2	398	(2.2)	34	(9.5)
Rib and thoracic wall					< 0.001c *
AIS = 3	18,008	(98.5)	288	(80.2)
AIS = 4	247	(1.4)	64	(17.8)
AIS = 5	29	(0.2)	7	(1.9)
Abdominal injury					< 0.001c*
Nil	17,286	(94.6)	306	(85.2)
AIS = 1	837	(4.6)	44	(12.3)
AIS = 2	154	(0.8)	9	(2.5)
ACS verification facility level					< 0.001b*
I	11,088	(60.6)	265	(73.8)
II	5654	(30.9)	81	(22.6)
III	1542	(8.4)	13	(3.6)
Injury mechanism					< 0.001b*
Fall	15,128	(82.7)	230	(64.1)
Motor vehicle accident	2592	(14.2)	111	(30.9)
Other	562	(3.1)	18	(5.0)
Comorbidities
Congestive heart failure	2788	(15.3)	42	(11.7)	0.074b
Current smoking	2566	(14.1)	75	(20.9)	< 0.001b*
Chronic renal failure	807	(4.4)	7	(2.0)	0.033b*
Cerebrovascular accident	1572	(8.6)	36	(10.1)	0.391b
Diabetes mellitus	5538	(30.4)	109	(30.4)	1.000b
Hypertension	12,961	(71.0)	252	(70.2)	0.793b
Chronic obstructive pulmonary disease	3953	(21.7)	94	(26.2)	0.048b*
Liver Cirrhosis	548	(3.0)	4	(1.1)	0.054b
Myocardial infarction	199	(1.1)	5	(1.4)	0.602c
Complication
Acute respiratory distress syndrome	48	(0.3)	8	(2.2)	< 0.001c*
Unplanned ICU admission	849	(4.6)	45	(12.6)	< 0.001b*
Unplanned intubation	556	(3.0)	39	(10.9)	< 0.001b*
Ventilator-associated pneumonia	59	(0.3)	12	(3.4)	< 0.001c*
Ventilator use	1329	(7.3)	123	(34.3)	< 0.001b*
ICU admission	7756	(42.5)	275	(76.6)	< 0.001b*
Total ventilator day	0.0	[0.0, 0.0]	0.0	[0.0, 3.0]	< 0.001a*
Total ICU LOS (days)	0.0	[0.0, 3.0]	5.0	[1.5, 10.0]	< 0.001a*
Total hospital LOS (days)	6.0	[4.0, 10.0]	13.0	[9.0, 19.0]	< 0.001a*
Mortality	1356	(7.4)	22	(6.1)	0.411b

Continuous variables: median [interquartile range]; Categorical variables: numbers (percentages)

ACS American College of Surgeons, AIS Abbreviated Injury Scale, ICU Intensive care unit, LOS Length of stay, SSRF Surgical stabilization of rib fractures

^a Mann–Whitney U test

^b Chi-square test

^c Fisher’s exact test

*Statistical significance (p < 0.05)

Following 1:3 propensity score matching, 294 patients in the SSRF group were matched with 882 patients who received conservative treatment (Table 2 and supplementary Table 6). Even after matching, SSRF patients exhibited higher rates of unplanned ICU admissions (11.2% vs. 7.0%, p = 0.031), unplanned intubations (10.2% vs. 6.1%, p = 0.026), and VAP (3.1% vs. 0.6%, p = 0.002). ICU LOS (5.0 vs. 2.0 days, p < 0.001) and total hospital LOS (12.0 vs. 8.0 days, p < 0.001) were also longer in the SSRF group. Notably, mortality was significantly lower in the SSRF group after matching (4.8% vs. 8.7%, p = 0.038). Subgroup analysis of the 359 patients who underwent SSRF revealed that 196 (54.6%) received early SSRF and 163 (45.4%) received late SSRF (Table 3). Age, sex, initial vital signs, or most comorbidities had no significant differences, except for a higher prevalence of COPD in the late SSRF group (31.9% vs. 21.4%, p = 0.033). Early SSRF was associated with better outcomes, including lower rates of unplanned ICU admissions (8.7% vs. 17.3%, p = 0.022), fewer ventilator days (0.0 [0.0–2.0] vs. 0.0 [0.0–7.0], p = 0.013), shorter ICU LOS (4.0 vs. 7.0 days, p < 0.001), and reduced total hospital LOS (11.0 vs. 16.0 days, p < 0.001). Mortality rates were comparable between the early and late SSRF groups (5.6% vs. 6.7%, p = 0.821). With a proper 1:3 PSM, the late SSRF group still showed significantly lower in-hospital mortality than the conservative group (3.8% vs. 10.9%, p = 0.023). Complication rates were also higher, including unplanned ICU admission (13.7% vs. 8.1%, p < 0.086), and unplanned intubation (13.7% vs. 4.8%, p = 0.001) (Supplementary Tables 7 and 8).

Table 2.

Outcomes of patients who received either SSRF or conservative treatments in 1:3 propensity score matching

			Conservative treatment (n = 882)		SSRF (n = 294)		p Value
Complication
Acute respiratory distress syndrome			6	(0.7)	6	(2.0)	0.085c*
Unplanned ICU admission			62	(7.0)	33	(11.2)	0.031b*
Unplanned intubation			54	(6.1)	30	(10.2)	0.026b*
Ventilator-associated pneumonia			5	(0.6)	9	(3.1)	0.002c*
Ventilator use			137	(15.5)	94	(32.0)	< 0.001b*
ICU admission			534	(60.5)	223	(75.9)	< 0.001b*
Total ventilation day (days)			0.0	[0.0, 0.0]	0.0	[0.0, 3.0]	< 0.001a*
Total ICU LOS (days)			2.0	[0.0, 5.0]	5.0	[1.0, 9.0]	< 0.001a*
Total hospital LOS (days)			8.0	[5.0, 13.0]	12.0	[9.0, 19.0]	< 0.001a*
Mortality			77	(8.7)	14	(4.8)	0.038b*

Continuous variables: median [interquartile range]; Categorical variables: numbers (percentages)

ICU Intensive care unit, LOS Length of stay, SSRF Surgical stabilization of rib fractures

^a Mann–Whitney U test

^b Chi-square test

^c Fisher’s exact test

*Statistical significance (p < 0.05)

Table 3.

Demographic characteristics of patients who received either early SSRF or late SSRF

	Early SSRF (n = 196)		Late SSRF (n = 163)		p Value
Age (years)	74.0	[64.8, 82.0]	71.0	[66.0, 80.5]	0.274a
Sex
Male	111	(56.6)	85	(52.1)	0.457b
Female	85	(43.4)	78	(47.9)
Systolic blood pressure (mmHg)	140.0	[122.0, 164.5]	136.0	[121.5, 154.2]	0.303a
Body temperature (degree)	36.7	[36.4, 36.8]	36.7	[36.4, 36.9]	0.562a
Pulse rate (/min)	88.0	[76.0, 101.0]	89.0	[76.0, 100.5]	0.669a
Respiratory rate (/min)	19.0	[17.0, 22.0]	20.0	[18.0, 23.0]	0.393a
Pulse oximetry (%)	96.0	[94.0, 98.0]	95.0	[93.0, 98.0]	0.120a
Glasgow Coma Scale score	15.0	[15.0, 15.0]	15.0	[15.0, 15.0]	0.003a*
Injury Severity Score	14.0	[9.0, 18.2]	14.0	[10.0, 20.5]	0.092a
Internal organ injuries of the head					0.238c
Nil	187	(95.4)	149	(91.4)
AIS = 2	5	(2.6)	6	(3.7)
ASI = 3	4	(2.0)	8	(4.9)
Thoracic injuries except rib and thoracic wall AIS ≥ 3					0.884b
Nil	22	(11.3)	21	(13)
AIS = 1	154	(79.0)	126	(77.8)
AIS = 2	19	(9.7)	15	(9.3)
Rib and thoracic wall					0.850c
AIS = 3	158	(80.6)	130	(79.8)
AIS = 4	35	(17.9)	29	(17.8)
AIS = 5	3	(1.5)	4	(2.5)
Abdominal injury					0.472c
Nil	163	(83.2)	143	(87.7)
AIS = 1	28	(14.3)	16	(9.8)
AIS = 2	5	(2.6)	4	(2.5)
ACS verification facility level					0.674b
I	148	(75.5)	117	(71.8)
II	42	(21.4)	39	(23.9)
III	6	(3.1)	7	(4.3)
Injury mechanism					0.571b
Fall	130	(66.3)	100	(61.3)
Motor vehicle accident	56	(28.6)	55	(33.7)
Other	10	(5.1)	8	(4.9)
Comorbidities
Congestive heart failure	24	(12.2)	18	(11.1)	0.868b
Current smoking	40	(20.4)	35	(21.5)	0.907b
Chronic renal failure	5	(2.6)	2	(1.2)	0.463c
Cerebrovascular accident	24	(12.2)	12	(7.4)	0.181b
Diabetes mellitus	60	(30.6)	49	(30.2)	1.000b
Hypertension	140	(71.4)	112	(68.7)	0.657b
Chronic obstructive pulmonary disease	42	(21.4)	52	(31.9)	0.033b*
Liver Cirrhosis	2	(1.0)	2	(1.2)	1.000c
Myocardial infarction	3	(1.5)	2	(1.2)	1.000c
Complications
Acute respiratory distress syndrome	4	(2.0)	4	(2.5)	1.000c
Unplanned ICU admission	17	(8.7)	28	(17.3)	0.022b*
Unplanned intubation	16	(8.2)	23	(14.2)	0.098b
Ventilator-associated pneumonia	6	(3.1)	6	(3.7)	0.967b
Ventilator use	59	(30.1)	64	(39.3)	0.087b
ICU admission	145	(74.0)	130	(79.8)	0.245b
Total ventilator day	0.0	[0.0, 2.0]	0.0	[0.0, 7.0]	0.013a*
Total ICU LOS (days)	4.0	[0.0, 8.0]	7.0	[2.0, 12.5]	< 0.001a*
Total hospital LOS (days)	11.0	[8.0, 15.0]	16.0	[11.0, 21.5]	< 0.001a*
Mortality	11	(5.6)	11	(6.7)	0.821b
Duration between admission and SSRF (hrs)	42.8	[26.5, 56.8]	113.8	[89.7, 143.4]	< 0.001a*

Continuous variables: median [interquartile range]; Categorical variables: numbers (percentages)

ACS American College of Surgeons, AIS Abbreviated Injury Scale, ICU Intensive care unit, LOS Length of stay, SSRF Surgical stabilization of rib fractures

^a Mann–Whitney U test

^b Chi-square test

^c Fisher’s exact test.

*Statistical significance (p < 0.05)

Discussion

Our study evaluated the impact of SSRF on clinical outcomes in functionally dependent patients with rib fractures. The findings revealed that patients who underwent SSRF experienced higher rates of complications, including VAP, unplanned intubation, and unplanned ICU admission. They also required longer ICU and hospital LOS. Despite these adverse events, SSRF was associated with a significant survival benefit after PSM. In functionally dependent patients with three or more rib fractures, along with AIS greater than 3 for the rib and thoracic wall, SSRF appears to offer the best chance of survival. However, clinicians should be aware that this population may face a heightened risk of postoperative complications. Performing early surgery once the patient’s condition stabilizes may reduce the risk of complications. Careful perioperative management and tailored support are essential to minimize these risks.

Rib fractures are known to be associated with significant morbidity and mortality, especially in older adults and individuals with comorbidities. The mortality burden is even more pronounced in elderly or frail populations. Bulger et al. (2000) reported that elderly patients with rib fractures had double the mortality rate of younger patients with similar injuries (22% vs. 10%, p < 0.001) [6]. Shibahashi et al. (2019) demonstrated that SSRF significantly reduced in-hospital mortality in patients with multiple rib fractures compared with non-operative management (95% CI [confidence interval], -14.8% to -8.0%), particularly in those with flail chest [21]. A meta-analysis by Sawyer et al. (2022) further supported the mortality benefit of SSRF (odds ratio: 0.63 (0.44, 0.03)) [22]. A systematic review also found that SSRF reduced mortality in elderly patients, with a mortality rate of 4% in the surgical group compared to 8% in the conservative treatment group [14]. Our study contributes to the growing body of literature by focusing specifically on functionally dependent individuals—a group defined not solely by age but by baseline disability and dependence in activities of daily living. In our cohort, SSRF was associated with significantly lower in-hospital mortality compared to conservative treatment, after adjusting for age, comorbidities, and injury severity. This underscores the importance of considering functional status—beyond chronological age or frailty indices—when evaluating patients for surgical intervention.

SSRF was associated with increased ventilator use, longer ICU and hospital LOS, and higher rate of ARDS, unplanned ICU admission, unplanned intubation, and VAP in the current study. Feng et al. (2023) reported that among trauma patients with rib fractures, adverse outcomes, including respiratory complications and mortality, increased with the number of fractured ribs, particularly in older and frail individuals [23]. Similarly, Zhao at al (2025) found that SSRF was not superior to conservative treatment in terms of ICU (MD [mean difference]1.01, 95% CI 0.08 to 1.94, p = 0.03) and hospital LOS (MD 1.92, 95% CI 0.82 to 3.01, p = 0.0006) [24]. Conversely, a meta-analysis by Long et al. (2020) concluded that SSRF was associated with significant reduced ICU (WMD [weighted mean difference] -5.72, 95% CI -7.31 to -4.13, p < 0.001) and hospital LOS (WMD − 8.48, 95% CI -11.34 to -5.63, p < 0.001), duration of mechanical ventilation (WMD − 4.93, 95% -8.79 to -1.07, p = 0.01), and risk of pneumonia (relative risk 0.4, 95% CI 0.3 to 0.53, p < 0.001) [25]. Hisamune et al. (2024) found that, SSRF reduced duration of mechanical ventilation (MD -4.62, 95% CI -7.64 to -1.60, p < 0.00001), ICU LOS (MD -3.05, 95% CI -5.87 to -0.22, p < 0.00001), and incidence of pneumonia (relative risk = 0.57, 95% CI 0.35 to 0.92, p = 0.02). These discrepancies suggest that complications are highly influenced by patient selection [26].

We also analyzed the effect of SSRF timing and found that early intervention led to significantly fewer ventilator days, fewer unplanned ICU admissions, and shorter ICU and hospital LOS—without increasing mortality. Despite a higher complication rate, late SSRF was still associated with a survival benefit compared to conservative treatment. These findings are consistent with previous reports. Wang et al. (2023) observed that early SSRF led to shorter ICU and hospital LOS and fewer ventilator days [27]. Similarly, Simmonds (2022), using data from the ACS-TQIP database, found that early SSRF resulted in shorter ICU LOS, reduced ventilation days, and fewer complications such as tracheostomy, VAP, and unplanned intubation [28]. Although mortality rates did not differ significantly between early and late SSRF groups in our cohort, the functional and resource-related advantages of early SSRF are clinically meaningful. These benefits are especially important for functionally dependent patients, who are particularly vulnerable to prolonged immobility and respiratory compromise. Therefore, the timing of SSRF should be a key consideration in clinical decision-making. Early intervention, when feasible, may enhance recovery and reduce complications in high-risk populations.

Our study found that while the late SSRF group had significantly more complications, but it demonstrated lower mortality compared to the conservative treatment group. This result suggests that while late SSRF may introduce more immediate risks, it may confer a survival advantage. The higher complication rates observed in the late SSRF group could be attributed to several factors. First, delayed rib fixation may lead to prolonged chest wall instability, which can increase the risk of respiratory complications. When surgical fixation is delayed beyond 72 h, increased pain, muscle weakness, and impaired pulmonary hygiene may contribute to prolonged ventilation and more complications [29]. Additionally, patients in this group may have had greater preoperative morbidity, with more extensive injuries, which might have predisposed them to higher rates of complications. Despite the increased complications, late SSRF enhances chest wall stability, reduced pain, and improved respiratory mechanics, leading to a survival advantage. Our results suggest that late SSRF may still be a valuable treatment option for patients who present with significant rib fractures but have contraindications for early surgery or when the initial response to nonoperative management is inadequate. Although late SSRF is associated with increased complications, the survival benefit suggests that timely surgical intervention, when possible, should be prioritized to reduce mortality in functional dependent traumatic patients.

The survival benefit observed in our study may be attributed to several factors. SSRF improves chest wall stability, respiratory mechanics, and pain control, thereby enabling better pulmonary hygiene and earlier mobilization [30, 31]. These advantages are particularly important in functionally dependent patients with limited physiologic reserves. Although the SSRF group experienced higher complication rates, these may reflect more intensive monitoring rather than the direct effects of surgery. In high-risk patients, even modest improvements in respiratory function and stability can translate to significant mortality reductions. Our findings support the selective use of SSRF in this population. Given the complex interaction of injury severity, frailty, and comorbidities, a multidisciplinary approach to patient selection and perioperative management is critical.

Future studies should aim to validate these findings through prospective, multicenter trials assessing short- and long-term outcomes, including post-discharge quality of life and functional status. Additionally, investigations into the cost-effectiveness of SSRF and the development of standardized protocols for patient selection and perioperative care are warranted to better define its role in functionally dependent patients.

Limitations

This study has several limitations. First, its retrospective design introduces potential selection bias and unmeasured confounding, even after propensity score matching. Second, the ACS-TQIP database consists data from participating hospitals, which may not be representative of the entire healthcare system. Third, the ACS-TQIP registry lacks several key variables that are routinely considered by treating surgeons, such as the degree of radiographic displacement, ventilator dependence, and refractory pain despite multimodal analgesia. The absence of these details limits our ability to precisely identify the clinical triggers that led to the decision to perform SSRF. Lastly, although we focused on in-hospital mortality and complications, long-term outcomes and quality-of-life measures were not assessed. Future prospective, multicenter studies with standardized protocols are needed to validate these findings, define precise surgical indications, and clarify which patient subgroups—especially among the functionally dependent—derive the greatest benefit from SSRF.

Conclusion

In summary, our study demonstrates that SSRF in functionally dependent trauma patients with multiple rib fractures and significant chest wall injury (AIS ≥ 3) is associated with a significant reduction in in-hospital mortality compared to conservative management. Although patients in the SSRF group experienced higher rates of certain in-hospital complications, the overall survival benefit supports the selective use of SSRF in this high-risk population. In terms of survival benefit, undergoing SSRF earlier is superior to late surgery; however, even late SSRF remains more beneficial than conservative treatment. These findings, in alignment with previous literature [14], highlight the potential of surgical intervention to improve outcomes in functionally dependent patients.

Electronic supplementary material

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Abbreviations

ACS-TQIP

American college of Surgeons-Trauma Quality Improvement Program

AIS

Abbreviated Injury Scale

ARDS

Acute respiratory distress syndrome

CI

Confidence interval

COPD

Chronic obstructive pulmonary disease

ED

Emergency department

ICU

Intensive care unit

ISS

Injury Severity Score

LOS

Length of stay

MD

Mean difference

PSM

Propensity score matching

SSRF

Surgical stabilization of rib fractures

VAP

Vantilator associated pneumonia

Author contributions

Yi Jung Chen, Chih Po Hsu, and Jen-Fu Huang conceived and designed the study. Yi Jung Chen, Chih Po Hsu, and Ya Chiao Lin collected and curated the dataset, and performed the statistical analysis. Yi Yu Lin prepared the visualizations, and drafted the manuscript. Jen-Fu Huang provided supervision and project administration. All authors contributed to interpretation of the data, critically revised the manuscript for important intellectual content, and approved the final version of the manuscript. All authors have read and approved the final manuscript and agree to be accountable for all aspects of the work.

Funding

No.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

The ethical approval for this study was obtained from Jen-Ai Hospital Institutional Review Board (IRB 202500042B0) on Apr. 14, 2025.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.