This meta-analysis included 11 studies (7 RCTs and 13 nRCTs) that evaluated 590 patients and compared postoperative functional scores and complications between surgery and conservative treatment. The pooled data shown no difference in functional scores between the two treatment modalities in RCT group and plate group. In general, there was no significant difference in the incidence of common complications between the surgery and conservation group, however, there were a significant difference in the subgroup of prosthesis group.
The proximal humeral anatomy is complex, fractures are extremely prone to occur during trauma[21]. It is believed that conservative treatment will not cause secondary trauma, and the medical cost is low, so it is suitable for the elderly or patients with intolerance to surgery. Although conservative treatment could lead to complications such as fracture displacement and joint stiffness, some scholars reported that non-surgical treatment had a good clinical efficacy. Den et al.[22] treated comminuted PHFs in the elderly with humeral head replacement and non-surgical methods respectively, and found that the long-term efficacy of non-surgical treatment was better than the former. At present, with the improvement of technology, LPHP and PHILOS plates were gradually applied and popularized. In particular, the design of PHILOS plate could break through the shortcomings of large incision exposure and severe local blood flow destruction in the traditional plate exposure process[23]. At the same time, it could also achieve reliable fixation effect through the cross-locking technology of multi-angle screws. The design of rotator cuff repair hole more achieves the combination of bone and soft tissue, plays the role of internal fixation bracket, and promotes the healing of fractures[24, 25]. In contrast to intramedullary nailing and prosthesis replacement techniques, surgeons are more likely to master plate internal fixation, which is more adaptable to PHF and easier to popularize. Nevertheless, Doshi et al.[26] proposed that the application of plate technology was based on individual differences of patients, and patients should be strictly selected and familiar with relevant anatomy. But Stanbury SJ[27] believed that RSA was superior to internal fixation.
In clinical practice, we often decide whether to use prosthesis based on age and degree of fracture comminution. When using different types of prosthesis, we found that the clinical effect of hemiarthroplasty often reached the concept of "all or nothing", with good efficacy in some patients and poor in others. But RSA could often achieve better results. Emmanuel Maugendre[28] believed that RSA had unique advantages in the treatment of PHF in elderly, with a 1-year survival rate that was 7–13% higher than that of femoral neck fractures. Jason Ferrel[29] agreed that RSA significantly improved forward shoulder flexion (range of motion greater than 10°) and had a relatively low revision rate (0.93%) compared to hemiarthroplasty. In this meta-analysis, according to the complications described in the literature[11, 14, 15, 20], we found RSA compared to hemiarthroplasty had a lower incidence of complications after surgery, Clark, NJ.[30] clinical trials also proved the point, at the same time, they thought primary RSA was effective in the treatment of PHF, lower in medical and surgical complications, RSA was also effective in patients over 80 years of age after a comprehensive evaluation. However, RSA is not a panacea, and it has its own limitations. For example, Cho CH[31] believed that we should pay great attention to the complications of acromion fractures that commonly occur after surgery. Since RSA is limited by glenoid loosening and instability, prosthesis implantation failure may occur, Song IS et al.[32] believed that hemiarthroplasty could better solve such problems, and postoperative follow-up score and joint range of motion were satisfactory.
Surgical treatment of PHF could be performed by different incision methods. In the meta-analysis we performed above, the extracted data shown that 9/11 studies used deltopectoral approach, and the other two were minimally invasive incisions[11, 16]. The choice of approach is determined by the experience of different surgeons that a particular incision is more effective, safer, or that they are better at operating a particular approach. Although the traditional deltopectoral approach had the advantage of showing clear intermuscular space, its exposure to the posterior displaced greater tuberosity was limited [33]. Guilherme Grisi Mouraria[34] demonstrated that the anterolateral approach could better expose the lateral surface of the humerus, which was conducive to the operation, but the axillary nerve injury and subacromial impingement were still complications that couldn’t be ignored. Other scholars believed that the subacromion anterolateral approach through the deltoid muscle had the advantages of minimally invasive, clear exposure, and no significant difference with the traditional deltopectoral approach in terms of reduction quality[35]. Harmer LS et al. examined two commonly used surgical approaches from cadaver tests, and they also demonstrated that the deltopectoral approach provided a better exposure to the front operating markers, while the anterolateral acromial approach provided a better rear exposure[36].
Due to the anatomical complexity of PHF and the nature of the fractures within the joint, many clinical complications occur, such as arthritis, joint stiffness, fracture nonunion, osteonecrosis, pain, joint dysfunction, fracture displacement, infection, bone resorption, and so on. However, nonunion of fracture and osteonecrosis are the most common and most likely causes of secondary surgery. Therefore, we summarized and analyzed the data of these two complications. Boesmueller et al. reported the follow-up results of 286 patients with PHF treated with PHILOS plate in 2016, among which 60 patients had postoperative complications, with a complication rate of 39%[37]。
A detailed analysis of the complications would help us to further guide the clinical work, Klug et al. performed RSA or open reduction and internal fixation with locking plate in 125 elderly with complicated PHF. Statistical analysis demonstrated that the incidence of postoperative complications in locking plate group was significantly higher than that in RSA group (15.8%). Therefore, it was recommended to perform RSA in the first phase in elderly patients with complex PHF[38]. This conclusion was consistent with our understanding.
Although we took various measures to reduce the influence of additional factors on the analysis results, there were still many potential limitations in this meta-analysis. First of all, no matter what kind of design is included in the standard, there will be methodological defects, so it is easy to cause some studies to be ignored. We consulted with professional librarians to get a better retrieval strategy, so as to minimize the impact on the results. Second, we conducted a comprehensive evaluation of RCTs and nRCTs at the initial stage, especially in terms of complications, which may lead to the deviation of the results due to problems in the trial design. Therefore, the analysis of subgroup analysis could ensure the comparability and scientificity of the results. In this process, we also found that the results of RCTs were more complete, which proved the accuracy of the design scheme and method, and the trial literature without omissions and exclusions were more accurate for the overall assessment. Thirdly, based on the grouping of the built-in objects, the overall classification into the plate group and the prosthesis group would bring about some differences in the results. As time goes on, more and more effective methods gradually replace the traditional methods, and meta-analysis is a systematic review process, which inevitably integrates a variety of fixed surgical methods. The subgroup analysis of these two methods was adopted to reduce the difference of results caused by the diversity of treatment methods. Fourth, according to the statistics from the baseline data, many surgical methods would produce different complications, and the differences here were caused by various reasons such as fracture types, and differences in the patients under surgery, which brought difficulties to the statistics of data collection. We selected the most common cases of fracture nonunion and osteonecrosis as a summary of complications, reducing individual differences in content, although this method may lead to some variation. Fifth, different classification, people of all ages would have different results, we conducted a comprehensive meta-analysis which would inevitably face the problem above, however, the above analysis, the cases of baseline data embodied mostly elderly patients and Neer3, 4 type fracture, common clinical characteristic of PHF determined the particularity. The relative limitation of the scope also helped us to reduce the impact on the results to some extent.
This meta-analysis is the first of its kind to use RCT and nRCT, as well as the combination of plate internal fixation and prosthesis replacement groups. In the initial strategy formulation, in order to avoid omissions, we adopted a more complete retrieval than before. In this process, unlike most articles, we searched, extracted and evaluated by two authors from different regions, and discussed in controversial cases through webinar, further reducing the influence of additional factors. Moreover, in the past two years, there had been no analysis of such content by any author. Nowadays, with the rapid update of implants and surgical techniques, meta-analysis that cannot be updated in time will obviously miss more important information comparisons. Therefore, our assessment results were more accurate and timely. All studies included a direct comparison of conservative versus surgical treatment for PHFs, and we rigorously evaluated their quality. We conducted this study based on the PRISMA statement.