Surgical and Non-Surgical Treatment for 3-Part and 4-Part Fractures of the Proximal Humerus: A Systematic Review of Overlapping Meta-Analyses

The effect of tuberosity healing on functional outcomes after reverse shoulder arthroplasty for proximal humerus fractures: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis compared clinical outcome measures in patients undergoing reverse shoulder arthroplasty (RSA) for proximal humerus fracture (PHF) with healed versus non-healed greater tuberosity (GT).

METHODS

We performed a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines querying PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane for studies that stratified results by the GT healing status. Studies that did not attempt to repair the GT were excluded. We extracted and compared clinical outcomes including postoperative forward flexion (FF), external rotation (ER), internal rotation (IR), Constant score, and complications and revision rates.

RESULTS

Of the included patients, 295 (78.5%) demonstrated GT healing while 81 did not (21.5%). The healed GT cohort exhibited increased postoperative FF (P < .001), ER (P < .001), IR (P = .006), and Constant score (P = .006) compared to the non-healed GT cohort. The overall dislocation rate was 0.8% with no study differentiating GT status of dislocation cases.

CONCLUSION

Healing of the GT after RSA for PHF yields improved postoperative range of motion and strength, whereas patient-reported pain and function were largely not affected by GT healing indicating merit to RSA for PHF regardless of the likelihood of the GT healing.

Does interferential current provide additional benefit to orthopedic rehabilitation for the patients with proximal humeral fractures? A randomized controlled study

BACKGROUND

Approximately 80% of all proximal humeral fractures (PHFs) are non-displaced or minimally displaced fractures, which can be treated with conservative treatment. This study investigated the effect of interferential current (IFC) added to orthopedic rehabilitation on shoulder function, pain, and disability in patients with PHF.

METHODS

This study was a prospective, double-blind, randomized, placebo-controlled conducted in physical medicine and rehabilitation outpatient clinic. Thirty-five patients were randomly separated into the IFC group (n = 18) and the sham group (n = 17). The orthopedic rehabilitation program was applied to all patients by the same physiotherapist three times a week for four weeks. Patients in the IFC group received the intervention for 20 minutes 3 times a week before the exercise. The same pads were performed for the sham group, but no electrical stimulation was applied. Constant-Murley score (CMS) for shoulder function, visual analog scale (VAS) activity pain, disabilities of the arm, shoulder, and hand (DASH) score, and paracetamol intake were recorded post-treatment, at 6 weeks and 18 weeks post-treatment.

RESULTS

The demographic and fracture characteristics were not different between the groups. Significant differences were observed in the IFC and sham group in intragroup comparisons of total CMS, VAS activity pain, DASH score, and paracetamol intake over time (p < 0.001). Significant improvement over time was valid for all pairwise comparisons in both groups. However, no significant differences were detected between the IFC and sham group.

CONCLUSION

IFC added to orthopedic rehabilitation could not appear to be an electrotherapy modality that could potentially benefit shoulder function and disability in patients with PHF.

A meta-epidemiological study found that meta-analyses of the same trials may obtain drastically conflicting results

OBJECTIVES

To assess how much protocols reduce methodological flexibility and variation of results in meta-analyses comparing operative with nonoperative treatments for proximal humerus fractures.

STUDY DESIGN AND SETTING

A meta-epidemiological study. We searched four bibliographic databases for eligible meta-analyses. We contacted the authors of the meta-analyses, requesting a copy of their protocol. We identified the included studies and extracted intervention effect data for functional outcome, quality of life, and adverse events. Using the same intervention effect data for each outcome domain, we conducted multiple meta-analyses using differing combinations of methodological choices (analytical scenarios) without restricting the available methodological choices (as if no protocol was used). For each protocol, we repeated this process but restricted the available choices to those listed in the protocol. We then compared the distributions of effect estimates with and without protocols. Methodological flexibility was estimated as the difference in number of possible meta-analyses and the variation of results as the difference between the most conflicting effect estimates.

RESULTS

We identified 23 meta-analyses, included 24 primary studies, and obtained three protocols. The protocols markedly reduced methodological flexibility (range for functional outcomes 94%-99%; quality of life 58%-76%; adverse events 87%-91%). The corresponding reduction in the variation of the results varied (range for functional outcomes; 33%-78%, quality of life; 10%-24%; adverse events 10%-13%).

CONCLUSION

Although the protocols consistently reduced methodological flexibility, the reduction in the variation (bias) of results varied. Consequently, review authors may obtain conflicting results based on the same data. We advise caution when interpreting the conclusions of meta-analyses with absent or imprecise protocols.

Proximal Humerus Fractures Treated Using Locking Plate: A Comparison Between Anatomical Reduction and Valgus Bent Locking Plate Fixation After Valgus Reduction

Introduction

Plate osteosynthesis is preferred for the treatment of proximal humerus fractures (PHFs). However, applying the locking plate flush against the bone may lead to varus malreduction and medial displacement of the humeral head. We hypothesized that slight valgus reduction and valgus bent locking plate fixation against potential varus deformation would yield better results than the traditional plate fixation.

Methods

We retrospectively reviewed patients with PHFs treated with locking plate fixation between March 2014 and July 2019. We evaluated changes in the neck-shaft angle (NSA) and humeral head height, as well as the development of complications postoperatively. Clinical outcomes were measured at 1-year post-surgery and at the last follow-up using the American Shoulder and Elbow Surgeons, the Disabilities of the Arm, Shoulder and Hand, and the Constant-Murley scores.

Results

A total of 58 patients with PHFs were enrolled in this study. They were divided into the valgus-aligned group (n = 28) and the anatomical group (n = 30). According to radiographic evaluation, immediate postoperative NSA was significantly greater in the valgus-aligned group. Moreover, the NSA measured at the last follow-up was significantly greater the valgus-aligned group. In contrast, the NSA became considerably more varus-aligned in the anatomical group.

Conclusion

The appropriate valgus reduction and valgus bending plate fixation could lead to better short-term results and improve the ability of proximal humerus locking plates to prevent varus collapse and fixation failure.

Level of Evidence

Level III, retrospective cohort design.

Surgical treatment of proximal humerus fractures: a systematic review and meta-analysis

INTRODUCTION

The purpose of this study was to perform a systematic review and meta-analysis of both randomized controlled and observational studies comparing surgical interventions for proximal humerus fractures.

METHODS

Systematic review of Medline, Embase, Scopus, and Google Scholar, including all level 1-3 studies from 2000 to 2022 comparing surgical treatment with ORIF, IM nailing, hemiarthroplasty, total and reverse shoulder arthroplasty (RTS) was conducted. Clinical outcome scores, range of motion (ROM), and complications were included. Risk of bias was assessed using the Cochrane Collaboration's ROB2 tool and ROBINs-I tool. The GRADE system was used to assess the overall quality of the body of evidence. Heterogeneity was assessed using χ² and I² statistics.

RESULTS

Thirty-five studies were included in the analysis. Twenty-five studies had a high risk of bias and were of low and very low quality. Comparisons between ORIF and hemiarthroplasty favored ORIF for clinical outcomes (p = 0.0001), abduction (p = 0.002), flexion (p = 0.001), and external rotation (p = 0.007). Comparisons between ORIF and IM nailing were not significant for clinical outcomes (p = 0.0001) or ROM. Comparisons between ORIF and RTS were not significant for clinical outcomes (p = 0.0001) but favored RTS for flexion (p = 0.02) and external rotation (p = 0.02). Comparisons between hemiarthroplasty and RTS favored RTS for clinical outcomes (p = 0.0001), abduction (p = 0.0001), and flexion (p = 0.0001). Complication rates between groups were not significant for all comparisons.

CONCLUSIONS

This meta-analysis for surgical treatment of proximal humerus fractures demonstrated that ORIF is superior to hemiarthroplasty, ORIF is comparable to IM nailing, reverse shoulder arthroplasty is superior to hemiarthroplasty but comparable to ORIF with similar clinical outcomes, ROM, and complication rates. However, the study validity is compromised by high risk of bias and low level of certainty. The results should therefore be interpreted with caution. Ultimately, shared decision making should reflect the fracture characteristics, bone quality, individual surgeon's experience, the patient's functional demands, and patient expectations.

LEVEL OF EVIDENCE

Level III; systematic review and meta-analysis.

How can clinicians choose between conflicting and discordant systematic reviews? A replication study of the Jadad algorithm

INTRODUCTION

The exponential growth of published systematic reviews (SRs) presents challenges for decision makers seeking to answer clinical, public health or policy questions. In 1997, an algorithm was created by Jadad et al. to choose the best SR across multiple. Our study aims to replicate author assessments using the Jadad algorithm to determine: (i) if we chose the same SR as the authors; and (ii) if we reach the same results.

METHODS

We searched MEDLINE, Epistemonikos, and Cochrane Database of SRs. We included any study using the Jadad algorithm. We used consensus building strategies to operationalise the algorithm and to ensure a consistent approach to interpretation.

RESULTS

We identified 21 studies that used the Jadad algorithm to choose one or more SRs. In 62% (13/21) of cases, we were unable to replicate the Jadad assessment and ultimately chose a different SR than the authors. Overall, 18 out of the 21 (86%) independent Jadad assessments agreed in direction of the findings despite 13 having chosen a different SR.

CONCLUSIONS

Our results suggest that the Jadad algorithm is not reproducible between users as there are no prescriptive instructions about how to operationalise the algorithm. In the absence of a validated algorithm, we recommend that healthcare providers, policy makers, patients and researchers address conflicts between review findings by choosing the SR(s) with meta-analysis of RCTs that most closely resemble their clinical, public health, or policy question, are the most recent, comprehensive (i.e. number of included RCTs), and at the lowest risk of bias.

Evidence analysis on the utilization of platelet-rich plasma as an adjuvant in the repair of rotator cuff tears

BACKGROUND

Platelet-rich plasma has been gaining popularity as an agent for biological augmentation either as the sole treatment modality or as an adjunct to surgical repair. There is substantial discrepancy in the results of the published meta-analyses; and the true efficacy and role of using autologous platelet-rich plasma (PRP) at the time of rotator cuff repair is still ambiguous.

AIM

To performed this systematic overview on the overlapping meta-analyses that analyzed autologous PRP as an adjuvant in the repair of rotator cuff tears and identify the studies which provide the current best evidence on this subject and generate recommendations for the same.

METHODS

We conducted independent and duplicate electronic database searches in PubMed, Web of Science, Scopus, Embase, Cochrane Database of Systematic Reviews, Reference Citation Analysis and the Database of Abstracts of Reviews of Effects on September 8, 2021 to identify meta-analyses that analyzed the efficacy of PRP as an adjuvant in the repair of rotator cuff tears. Methodological quality assessment was made using Oxford Levels of Evidence, AMSTAR scoring and AMSTAR 2 grades. We then utilized the Jadad decision algorithm to identify the study with the highest quality to represent the current best evidence to generate the recommendation.

RESULTS

Twenty meta-analyses fulfilling the eligibility criteria were included. The AMSTAR scores of the included studies varied from 6-10 (mean: 7.9). All the included studies had critically low reliability in their summary of results due to their methodological flaws according to AMSTAR 2 grades. Significant heterogeneity was observed in the reporting of VAS, function outcome scores (long-term UCLA score, ASES score, SST score), operative time and long-term re-tear rates. Recent meta-analyses are more supportive of the role of intra-operative administration of PRPs at the bone-tendon interface in improving the overall healing and re-tear rates, functional outcome and pain. The initial size of the tear and type of repair performed do not seem to affect the benefit of PRPs. Among the different preparations used, leucocyte poor (LP)-PRP possibly offers the greatest benefit as a biological augment in these situations.

CONCLUSION

Based on this systematic overview, we give a level II recommendation that intra-operative use of PRPs at the bone-tendon interface can augment the healing rate, reduce re-tears, enhance functional outcome and mitigate pain in patients undergoing arthroscopic rotator cuff repair. LP-PRP possibly offers the greatest benefit in terms of healing rates, as compared with other platelet preparations.

The influence of fracture severity on postoperative outcome and quality of life after locking plate fixation of proximal humeral fractures

Objective:

For proximal humeral fractures open reduction und internal fixation (ORIF) with a fixed-angle plate is considered the gold standard for surgical management. However, it can lead to poor functional outcomes and is associated with postoperative complications. Therefore, the purpose of this study was to investigate the influence of fracture severity by applying a new classification (simple versus complex) on clinical outcome and quality of life after ORIF of proximal humerus fractures.

Methods:

We conducted a prospective clinical study with an average follow-up period of 12 (SD 1) months after ORIF of proximal humeral fractures with a fixed-angle plate. The postoperative function and quality of life was measured using the Oxford Shoulder Score (OSS) and the Constant Score. Data was tested for statistical significance with the Mann-Whitney test and Fisher's exact test. Based on the findings of this study a simplified fracture classification system has been developed.

Results:

Seventy-two patients with a mean age of 65 years (SD 12) with 69% being males were included. According to the Neer classification, 35% (n=25) non-displaced (“one-part fractures”), 19% (n=14) two-part fractures, 15% (n=11) three-part fractures and 31% (n=22) four-part fractures were detected. Regarding the AO/OTA classification, 18% (n=13) were type A fractures, 43% (n=31) type B and 39% (n=28) type C fractures. From these criteria we derived our own fracture classification, including 50% (n=36) simple and 50% (n=36) severe fractures. Patients with simple fracture types achieved significantly higher total values in the Constant Score as well as the OSS (p=0.008; p=0.013). The cumulative incidence of complications in the entire patient collective was 14% (n=10) with humeral head necrosis (n=5) occurring only in the severe fracture group.

Conclusions:

The postoperative clinical outcome as well as the incidence of humeral head necrosis after ORIF of proximal humeral fractures with a fixed-angle plate correlates with the fracture type and severity. The newly derived fracture classification into simple and severe fractures is suitable with regard to clinical results and complication rate. However, prospective studies comparing ORIF vs. conservative treatment of proximal humeral fractures of the same severity are required.

Level of Evidence:

III

Is Platelet-Rich Plasma Effective in Enhancing Spinal Fusion? Systematic Overview of Overlapping Meta-Analyses

STUDY DESIGN

Systematic review.

OBJECTIVES

We performed this systematic overview on overlapping meta-analyses that analyzed the role of platelet-rich plasma(PRP) in enhancing spinal fusion and identify which study provides the current best evidence on the topic and generate recommendations for the same.

MATERIALS AND METHODS

We conducted independent and duplicate electronic database searches in PubMed, Web of Science, Embase, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects till October-2020 for meta-analyses that analyzed the role of PRP in spinal fusion procedures. Methodological quality assessment was made using Oxford Levels of Evidence, AMSTAR scoring, and AMSTAR 2 grades. We then utilized the Jadad decision algorithm to identify the study with highest quality to represent the current best evidence to generate recommendations.

RESULTS

3 meta-analyses fulfilling the eligibility criteria were included. The AMSTAR scores of included studies varied from 5-8(mean:6.3) and all included studies had critically low reliability in their summary of results due to their methodological flaws according to AMSTAR 2 grades. The current best evidence showed that utilization of PRP was not associated with significant improvement in patient-reported outcomes such as Visual Analog Score for pain compared to the standard fusion procedure. Moreover, PRP was found to be associated with lower fusion rates.

CONCLUSION

Based on this systematic overview, the effectiveness of PRP as a biological agent in augmenting spinal fusion is limited. Current evidence does not support the use of PRP as an adjuvant to enhance spinal fusion.

The forgotten fragment: additional lesser tuberosity fixation of 4-part proximal humeral fractures-a biomechanical investigation

BACKGROUND

Fractures of the proximal humerus are common. The most frequent surgical treatment option is open reduction and locking plate fixation. Multifragmentary fractures, including 3- and 4-part fractures, are especially challenging to treat because they correlate with an increased risk of fixation failure. In the past, several mechanisms of additional fixation were investigated, but none directly addressed the lesser tuberosity (LT). The goal of this study was to investigate the biomechanical impact of additional anterior fracture fixation in lateral locked plating (LLP) of 4-part proximal humeral fractures (PHFs).

METHODS

Twenty-seven fresh frozen human shoulder specimens (mean age, 80 years) with intact rotator cuffs (RCs) were randomized into 4 groups: 3-part PHF with LLP and RC cerclage (n = 6); 4-part PHF with LLP and RC cerclage as standard of care (n = 7); 4-part PHF with LLP, RC cerclage, and 2 anterior 3.5-mm cortical screws (n = 7); and 4-part PHF with LLP, RC cerclage, and additional anterior one-third tubular plate (additional anterior plating [AAP], n = 7). Static load of the RC was simulated with weights. A force-controlled cyclic loading test was performed with a servo-hydraulic testing machine, followed by load-to-failure testing. An optical motion capture system recorded humeral head range of motion.

RESULTS

LLP of a 4-part PHF showed more humeral head motion than LLP of a 3-part PHF without fracture of the LT (P < .001). Fixing the LT to the humeral head with two 3.5-mm screws significantly reduced humeral head motion compared with LLP with RC cerclage alone (P < .006). Using AAP significantly increased the construct stiffness compared with the standard of care (P = .03).

CONCLUSION

LLP of a 4-part PHF is biomechanically less stable than LLP of a 3-part PHF without fracture of the LT. Additional screw fixation of the LT in 4-part PHFs improves stability compared with LLP alone. In case of metaphyseal comminution, AAP is favorable from a biomechanical perspective.

Projections of Primary and Revision Shoulder Arthroplasty until 2040: Facing a Massive Rise in Fracture-Related Procedures

Although the demand for shoulder arthroplasties has reached its highest number worldwide, there remains a lack of epidemiologic data regarding recent and future trends. In this study, data for all shoulder arthroplasties (hemiarthroplasty, reverse/anatomic shoulder arthroplasty) from the nationwide inpatient statistics of Germany (2010–2019) and population forecasts until 2040 were gathered. A Poisson and a negative binomial approach using monotone B-splines were modeled for all types of prostheses to project the annual number and incidence of primary and revision arthroplasty. Additionally, trends in main indicators were also gathered and expected changes were calculated. Overall, the number of primary shoulder replacements is set to increase significantly by 2040, reaching at least 37,000 (95% CI 32,000–44,000) procedures per year. This trend is mainly attributable to an about 10-fold increased use of fracture-related reverse shoulder arthroplasty in patients over 80 years of age, although the number of procedures in younger patients will also rise substantially. In contrast, hemiarthroplasties will significantly decrease. The number of revision procedures is projected to increase subsequently, although the revision burden is forecast to decline. Using these country-specific projection approaches, a massive increase of primary and revision shoulder arthroplasties is expected by 2040, mainly due to a rising number of fracture-related procedures. These growth rates are substantially higher than those from hip or knee arthroplasty. As these trends are similar in most Western countries, this draws attention to the international issue, of: if healthcare systems will be able to allocate human and financial resources adequately, and if future research and fracture-prevention programs may help to temper this rising burden in the upcoming decades.

The methodological quality was low and conclusions discordant for meta-analyses comparing proximal humerus fracture treatments: a meta-epidemiological study

OBJECTIVE

To investigate the association between methodological quality and reported conclusions of meta-analyses comparing operative with non-operative treatments for proximal humerus fractures.

STUDY DESIGN AND SETTING

Cross-sectional meta-epidemiological study. We searched EMBASE, PubMed, The Cochrane Library, and Web of Science for systematic reviews with meta-analyses comparing non-operative with operative treatments for proximal humerus fractures. Methodological quality was assessed using AMSTAR2 and the reported conclusions were scored for three outcome domains (functional outcome, quality of life, and harm) on a scale from 1 to 6. The Mann-Whitney and Kruskal-Wallis tests were used to investigate the association between methodological quality and reported conclusions.

RESULTS

We included 21 systematic reviews: 19 pairwise meta-analyses and 2 network meta-analyses, although there are only 8 published randomized controlled trials. Most (n = 18) of the meta-analyses were rated as critically low quality, while the remaining 1 was rated as high quality. The conclusions were discordant for all three outcome domains, even for meta-analyses reporting similar inclusion criteria. We could not perform most of the statistical tests due to the predominantly critically low quality.

CONCLUSION

The methodological quality was so predominantly critically low that it was not possible to evaluate the association between methodological quality and reported conclusions.

Efficacy of Hemiarthroplasty vs. Locking Plate Fixation for Proximal Humerus Fractures: A Meta-Analysis

Background: Proximal humerus fractures are common in a clinic and account for ~6% of all adult fractures. Hemiarthroplasty (HA) or locking plate (LP) fixation is currently recommended for the treatment of complex proximal humerus fractures (PHFs); however, there is no uniform standard for optimal surgical treatment or functional recovery. We conducted a meta-analysis to compare the efficacy of LP and HA in the treatment of PHFs. Methods: Relative studies associated with HA and LP were searched in December 2020 in the PubMed, Embase, Cochrane Library, and OVID databases. The quality of the studies, functional outcomes (including the Constant-Murley score (CMS), American Shoulder and Elbow Surgeons Score (ASES), Simple Shoulder Test (SST), Short Form Health Survey (SF-12v2), complications, and reoperation rate were extracted and analyzed with the Stata 14.0 software. Results: A total of 958 patients from 12 studies were included in the meta-analysis, which showed that patients treated with LP had a significantly lower reoperation rate, a higher complication rate, and a higher CMS score than those treated with HA. There were no significant differences in ASES, SST, or SF-12v2 scores between treatment groups. Conclusions: Compared with HA, LP exhibited better clinical efficacy in some aspects. However, large sample and randomized, controlled studies are needed for further validation.

Autologous bone marrow derived mesenchymal stem cell therapy for osteonecrosis of femoral head: A systematic overview of overlapping meta-analyses

STUDY DESIGN

Systematic Review.

OBJECTIVES

We performed this systematic overview on the overlapping meta-analyses that analyzed autologous bone marrow-derived mesenchymal stem cell(BM-MSC) therapy along with core decompression(CD) for the management of osteonecrosis of the femoral head(ONFH) and identify which study provides the current best evidence on the topic and generate recommendations for the same.

MATERIALS AND METHODS

We conducted independent and duplicate electronic database searches in PubMed, Web of Science, Embase, Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effects till September 2020 for meta-analyses that analyzed the efficacy of BM-MSC therapy along with CD for ONFH. Methodological quality assessment was made using Oxford Levels of Evidence, AMSTAR scoring, and AMSTAR 2 grades. We then utilized the Jadad decision algorithm to identify the study with the highest quality to represent the current best evidence to generate the recommendation.

RESULTS

6 meta-analyses fulfilling the eligibility criteria were included. The AMSTAR scores of the included studies varied from 4 to 9 (mean:7) and all the included studies had critically low reliability in their summary of results due to their methodological flaws according to AMSTAR 2 grades. The current best evidence showed that utilization of BM-MSC therapy along with CD for ONFH resulted in significant improvement in Harris hip scores at 12 and 24 months along with a significant reduction in the necrotic area of the femoral head and the rate of conversion to total hip arthroplasty(THA) without a significant rise in adverse events due to the procedure.

CONCLUSION

Based on this systematic overview, we give a Level II recommendation that BM-MSC therapy is more efficacious along with CD in the management of ONFH compared to CD alone. BM-MSC therapy provides better pain relief with significant functional improvement and delaying the collapse of the femoral head thereby preventing further treatment such as THA.

Unilateral versus bilateral pedicle screw fixation in lumbar fusion: A systematic review of overlapping meta-analyses

OBJECTIVES

To carry out a systematic review on the basis of overlapping meta-analyses that compare unilateral with bilateral pedicle screw fixation (PSF) in lumbar fusion to identify which study represents the current best evidence, and to provide recommendations of treatment on this topic.

METHODS

A comprehensive literature search in PubMed, Embase, and the Cochrane Library databases was conducted to identify meta-analyses that compare unilateral with bilateral PSF in lumbar fusion. Only meta-analyses exclusively covering randomized controlled trials were included. Study quality was evaluated using the Oxford Levels of Evidence and Assessment of Multiple Systematic Reviews (AMSTAR) instrument. Then, the Jadad decision algorithm was applied to select the highest-quality study to represent the current best evidence.

RESULTS

A total of 9 studies with Level II of evidence fulfilled the eligibility criteria and were included. The scores of AMSTAR criteria for them varied from 5 to 9 (mean 7.78). The current best evidence detected no significant differences between unilateral and bilateral PSF for short-segment lumbar fusion in the functional scores, length of hospital stay, fusion rate, and complication rate. However, unilateral PSF involved a remarkable decrease in operative time and blood loss but increase of cage migration when compared with bilateral PSF.

CONCLUSIONS

According to this systematic review, unilateral PSF is an effective method of fixation for short-segment lumbar fusion, has the advantages of reduced operative time and blood loss over bilateral PSF, but increases the risk of cage migration.