This retrospective study showed that for elderly individuals who suffered PFNA failure, compared with a UTA device, a CTA device had a noteworthy advantage in regard to functional scores and the rate of key orthopaedic complications. Our findings are in line with those of previous studies[9-11] that a CTA device is more effective than a UTA device in primary PFNA revision. In addition, for elderly patients with clear failure of PFNAs, CTA revision should be performed as soon as possible, regardless of whether these individuals have symptoms. With the increasing numbers of failed PFNAs, expanded application of UTA or CTA devices is predictable. Nonetheless, individuals are not eager to suffer from the excessive complications initiated by UTA or CTA revision for treating failed PFNAs. Thus, when a revision procedure is proposed, CTA revision for failed PFNAs could be an enticing option.
Findings from previous studies[13, 14] have demonstrated the superiority of CTA devices over UTA devices. Although significant differences in functional scores were detected, we did not detect noteworthy distinctions in the incidence of key orthopaedic complications during the first 3 years. For patients with PFNA failure, the mid-term prognosis of UTA or CTA devices remains controversial. A growing body of evidence[16, 17] suggests that the differences in therapeutic efficacy between a UTA device and a CTA device for a failed PFNA were primarily in the functional scores. Nonetheless, a short-term follow-up study involving 112 patients with failed PFNAs showed that there was no noteworthy distinction between a UTA device and a CTA device regarding functional assessment, and the use of UTA device did not lead to an increase in orthopaedic-related complications.
The evidence on which the decision to use a prosthesis to revise a failed PFNA was based was vague and controversial. In addition, the operating specifications for reducing or avoiding mechanical complications were rarely mentioned in the previous literature[7, 20]. Consistent with previous randomized trials[16, 14], we did not observe a remarkable difference in mechanical complications between groups at the end of the 3-year follow-up. In the current study, the incidence of major orthopaedic complications was acceptable. However, there may be some differences in the comparison of quantitative variables, mainly due to the previous studies[5, 12] involving diverse research subjects, such as multi-ethnic groups, different age groups or groups with younger subjects. According to previous experience, UTA devices tend to be used in younger, non-osteoporotic patients, while CTA devices are frequently used in older osteoporosis patients. Based on this conclusion, we could conclude that CTA devices tend to be adopted for PFNA failure in elderly individuals. However, for younger groups, the choice of prosthesis is still controversial. Recent studies[22, 19] have shown that CTA devices have noteworthy advantages in terms of functional outcomes and orthopaedic complications for failed PFNAs in young patients compared to UTA devices.
UTA devices are now infrequently utilised in elderly patients with osteoporosis. This infrequent use is largely attributable to a regrettably high orthopaedic complication rate, although improvements in crosslinked polyethylene have increased the biomaterial benefits of UTA devices over CTA devices. Nonetheless, the number of individuals suffering from UTA-related orthopaedic complications continues to increase. No consensus has been reached on the indications and timing of revision for PFNAs, and the rates of the revision of PFNAs differ among studies[4, 14]. Furthermore, a series of studies[23, 24] have reported that conservative management has successfully treated a large number of patients with failed PFNAs. In this situation, it is quite difficult for surgeons to manage such patients with failed PFNAs, and conservative management or revision has become an intractable alternative. However, recent evidence[22, 2] suggests that UTA or CTA revision is generally associated with a significant improvement in functional outcomes. Therefore, such intervention should be performed regardless of the complications initiated by UTA or CTA revision.
For both the UTA and CTA groups, symptomatic patients experienced greater functional improvement after undergoing revision than asymptomatic patients. However, for asymptomatic patients, a CTA device provided a significant functional improvement compared to a UTA device at the final follow-up, as evidenced by the key orthopaedic complications, but for symptomatic patients, no significant differences were detected in the functional outcomes at the final follow-up. This observation may indicate the benefits of patients undergoing CTA revision before symptoms appear. However, despite the high rate of complications, symptomatic patients could obtain more functional benefits from revision than asymptomatic patients. Notably, the functional scores of asymptomatic patients after revision did not show a significant decline, and these patients continued to maintain a high functional level. The delay of revision surgery for asymptomatic patients until after symptoms appear may lead to poor functional outcomes. However, a definitive surgical approach may be tricky to determine for some patients; therefore, we advocate a comprehensive evaluation of patients.
The present review has several limitations. First, this study was retrospective in design and, therefore, susceptible to inherent inclusion and exclusion biases that cannot be adjusted. Second, the conclusions may have been influenced by the relatively small population, inappropriate control of confounding factors, and short-term follow-up. Third, when key orthopaedic complications are used as an endpoint of the study, some complications are inevitably ignored, which may have a certain impact on the judgement of the results. However, several complications included in our study have been frequently reported in previous studies. Fourth, in the baseline data, we did not mention the patient's occupational type or other potential medical diseases, but these potential risk factors that can lead to UTA or CTA revision may play a critical role in some patients. Finally, simple utilisation of HHSs and major orthopaedic complications as study endpoints to measure patient functional outcomes and orthopaedic complications may have limitations.