According to the Chinese consensus for the surgical treatment of traumatic rib fractures 2021 (C-STTRF 2021) , SSRF is recommended for multiple rib fractures with flail chest (IIA). patients without surgical contraindications and without flail chest can also benefit from surgical treatment (IIB). The consensus encourages the surgical treatment of rib fractures. Although there is no clear evidence that surgical treatment improves healing in patients, it has been proven to improve lung function[[i]]. Additionally, an RCT study showed that it relieved pain[[ii]], and it reduces the disability rate and time to return to work[[iii]].
However, as a special population, there is still a lack of specific research on the evaluation of surgical treatment of rib fractures in patients over 60 years old. Rib fracture is the most common chest trauma and is often associated with adverse outcomes such as lung infection, ARDS, respiratory failure, and death[[iv],[v]]. These poor outcomes are mainly due to several reasons. First, elderly individuals often have a poor ability to repair the physical damage of rib fracture, and they often have osteoporosis. The osteogenic ability of osteoblasts is reduced in older adults; in contrast, the bone resorption capacity of osteoclasts is enhanced[[vi]]. Therefore, the quality of fracture healing is poor, and the proportion of delayed healing and bone nonunion is high[[vii]]. Second, respiratory restriction due to pain makes older individuals more at risk of adverse outcomes[[viii]]. Third, elderly patients often have poor cardiopulmonary function and underlying diseases, which are also associated with poor outcomes[[ix]]. Finally, many elderly people have taken anticoagulant drugs for a long time, which complicates surgery and makes it difficult to perform[[x],[xi]].
This study showed that compared with conservative treatment, surgical treatment can extend the length of hospital stay to some extent, but it has advantages in terms of the fracture healing rate, fracture healing time and fracture pain relief.
Slobogean GP et al.[[xii]] conducted a meta-analysis of previous studies and found that for conservative treatment, the lengths of hospital stay were 13, 15, 18, and 21 days; the lengths of ICU stay were 15, 18, 20, and 21 days; and the durations of mechanical ventilation were 13, 15-18, and 20-22 days. Surgical treatment reduced the average length of hospital stay and the average length of ICU stay after mechanical ventilation by 4.0 days, 4.8 days, and 7.5 days, respectively. There was a statistically significant difference between surgical treatment and conservative treatment, and the findings suggested that SSRF could better promote symptom relief and functional recovery in elderly patients with rib fracture compared with conservative treatment. In the present study, the lengths of hospitalization, ICU stay and mechanical ventilation in the two groups were generally shorter than the above values, which may be related to the quality of the treatment measures taken in our centre or the exclusion of patients with severe head and abdominal complications.
We found that there was no significant difference in the length of ICU stay or mechanical ventilation between the two groups. However, the length of hospitalization was significantly longer in the surgery group than in the control group. We analysed the baseline factors that may have affected the length of hospital stay. Except for the pleural effusion group, the length of stay in the surgery group was significantly longer than in the control group regardless of whether the patients had flail chest, pneumothorax or atelectasis before surgery. This may be related to the poor recovery ability of elderly individuals after surgery. A recent meta-analysis by Choi J[[xiii]] showed that compared with younger patients, elderly patients have a higher incidence of osteoporosis and significantly higher postoperative complications of rib fracture, and they are more prone to plate fracture, displacement and infection after surgery.
Few datasets on rib fractures in elderly individuals have been available for previous studies. Nevertheless, previous studies have found that the overall mortality for patients with rib fracture ranges from 0.0% to 33.3%, compared with 0.0% to 30% for patients who received SSRF and 0.0% to 57.9% for those who received nonsurgical treatment[10,[xiv],[xv]]. These findings indicate that surgical treatment can significantly reduce patient mortality . A meta-analysis by Cataneo AJ  found that there was no significant difference in mortality between surgery and conservative treatment groups in patients with rib fractures. The causes of death were often pneumonia, pulmonary embolism, mediastinum, and septic shock. However, Shibahashi K et al. . pointed out that the sample size of this meta-analysis was small (n=123) and therefore the correlation analysis was not reliable. In our study, the mortality rate decreased significantly after sample matching, indicating that the mortality results are indeed affected by the sample size. Mortality in both groups was very low, especially in the surgery group, which had a lower mortality than the control group, but the difference was not statistically significant.
Marasco S et al.  found that the fracture healing rates (including complete union and partial union) of both fixed and unfixed bone ends were very high in flail chest patients 3 months after SSRF treatment (88.46% and 86.54%, respectively), but there was no significant difference between the two groups. In the present study, the fracture healing rates of the surgery group and the control group were also rather high 9 months after surgery, at 96.67% and 88.89%, respectively. The fracture healing rates of the flail chest group and the control group were also as high as 95.83% and 80.00%, respectively. However, we found that the fracture healing rate of the surgery group was significantly higher than that of the control group. The fracture healing time of the surgery group was 3 months on average, while that of the control group was 3-7 months. The healing time of the surgery group was significantly shorter than that of the control group. The ribs move with breathing, and if not fixed, the broken ends of the fracture will move in response to breathing or coughing owing to shear and axial movements[[xvi]]. Compared with axial motion, shear motion has a higher torsion stress. Shear motion delays the healing of the diaphysis, while axial motion promotes healing. In addition, shear motion affects the angiogenesis process in the periosteum healing tissue[[xvii]].
Patients in the surgery group were significantly better than those in the control group in terms of the improvement in pain score and the duration of pain medication use[[xviii]]. This study showed that SSRF more significantly and rapidly relieved pain symptoms in the elderly patients compared with conservative treatment. However, surgical treatment did extend the hospital stay. Therefore, the surgical treatment of SSRF has pros and cons—it can accelerate patient recovery and improve their quality of life, but it may extend the length of hospital stay and increase the risk of hospitalization during the perioperative period. Doctors should carefully evaluate a patient’s condition and surgical indications and the risks and benefits of surgery to choose the optimum treatment[30,[xix],[xx]].
Based on a large amount of previous clinical experience, our centre has developed indications for the selection of surgery to treat elderly patients with rib fracture. At present, our centre recommends SSRF for elderly patients with flail chest and who have no contraindications to surgery. For non-flail chest patients with two or more rib fractures and obvious displacement of the broken ends in more than half of the fractures, surgery is recommended. For patients with non-flail chest with complications, conservative analgesia and respiratory management should be routinely used. If not effective, patients with early severe pain and well-aligned broken fracture ends without obvious surgical contraindications are recommended for surgical treatment. patients with severe complications should be treated with positive pressure ventilation by an endotracheal intubation ventilator. For patients with poor conservative treatment, respiratory deterioration and long-term chest floating, if there is no obvious contraindication, physicians should consider SSRF.
There are some limitations to this study. The number of patients was greatly reduced after matching, which may have influenced the results. This study was a single-centre study, and the results showed that the length of hospital stay, length of ICU stay, mechanical ventilation duration, and mortality were all lower than in previous studies. As a primary trauma and burn treatment centre located in Beijing, we receive critical chest trauma patients from all over the country, and our institute is a leader in surgical quality, ICU quality and nursing quality in China. Therefore, the results may not be generalisable to other treatment centres. To more objectively evaluate the curative effect of SSRF in China, studies are needed with larger sample sizes and that include more centres.
In conclusion, we studied the efficacy of two treatment methods for elderly rib fracture patients using the propensity score matching method. We found that surgical stabilization of rib fractures extended the length of hospital stay compared with conservative treatment, but it had advantages in terms of the fracture healing rate, healing time, and pain relief. For rib fractures in elderly individuals, surgical treatment does not significantly increase mortality when applied under strict surgical indications.