Platelet-rich plasma enhances bone union in posterolateral lumbar fusion: A prospective randomized controlled trial

Bone union-promoting effect of romosozumab in an ovariectomized rat posterolateral lumbar fusion model

Spinal fixation surgery has been increasingly performed in patients with osteoporosis. Romosozumab, a drug that was introduced in Japan recently, is known to possibly promote bone healing. However, few studies have reported the therapeutic effects of romosozumab in clinical practice in Japan. Therefore, here, we investigated the effects of romosozumab dosage on bone fusion promotion using an ovariectomized rat spinal fusion model. Eight-week-old female Sprague-Dawley rats were matched by body weight and divided into three groups: 1.0 romosozumab (R) group (Evenity®, 25 mg/kg), 1/10R group (Evenity®, 2.5 mg/kg), and control (C) group (saline). Subcutaneous injections were administered twice a week for 8 weeks postoperatively. Computed tomography scans were performed every 2 weeks from the time of surgery till 8 weeks postoperatively. The mean fusion rates in terms of volume were significantly higher in the R groups [1/10R, 1.0R] than in the C group from 4 weeks postoperatively. The rate of increase was significantly higher in the 1.0R group from 4 weeks postoperatively and in the 1/10R group from 6 weeks postoperatively, than in the C group. The proportion of trabecular bone area was approximately 1.5 times higher in the R groups than in the C group. No significant differences were observed between the R groups. Our results suggest that romosozumab stimulates bone growth at the graft site, and similar effects were achieved at 1/10 of the standard dosage.

Combined effect of DBM, PRP, and bone marrow fluid on bone union in a rat posterolateral fusion model

Platelet-rich plasma (PRP) promotes bone union through osteoinduction. We investigated whether adding demineralized bone matrix (DBM), derived naturally from biomaterial and with various growth factors, for osteoconductivity and bone marrow fluid for osteogenesis results in different bone unions. Eight-week-old male Sprague-Dawley rats were divided into four groups of five based on transplantation material: sham control (C group); DBM alone (D group); DBM + PRP (DP group); and DBM + PRP + bone marrow fluid (DPB group). After posterolateral fusion at L3-5, postoperative weekly CT imaging determined average number of bone union in facet joints (4 joints × 5 animals = 20 joints) and bone formation. Pathological evaluation and bone strength were assessed using 3-point bending two weeks postoperatively. Facet joint bone union at four weeks postoperatively was 4/20 (20%, DP group) and 8/20 (40%, DPB group) joints. Six weeks postoperatively, it was 7/20 (35%, D group), 12/20 (60%, DP group), and 16/20 (80%, DPB group). Eight weeks postoperatively, it was 13/20 (65%, D group), 17/20 (85%, DP group), and 20/20 (100%, DPB group), suggesting that DPB > DP > D > C. Bone formation and bone strength showed a similar DPB > DP > D > C group trend. Adding PRP and bone marrow fluid to DBM promotes bone union and strength.

Advances in Platelet-Rich Plasma Treatment for Spinal Diseases: A Systematic Review

Spinal diseases are commonly associated with pain and neurological symptoms, which negatively impact patients' quality of life. Platelet-rich plasma (PRP) is an autologous source of multiple growth factors and cytokines, with the potential to promote tissue regeneration. Recently, PRP has been widely used for the treatment of musculoskeletal diseases, including spinal diseases, in clinics. Given the increasing popularity of PRP therapy, this article examines the current literature for basic research and emerging clinical applications of this therapy for treating spinal diseases. First, we review in vitro and in vivo studies, evaluating the potential of PRP in repairing intervertebral disc degeneration, promoting bone union in spinal fusion surgeries, and aiding in neurological recovery from spinal cord injury. Second, we address the clinical applications of PRP in treating degenerative spinal disease, including its analgesic effect on low back pain and radicular pain, as well as accelerating bone union during spinal fusion surgery. Basic research demonstrates the promising regenerative potential of PRP, and clinical studies have reported on the safety and efficacy of PRP therapy for treating several spinal diseases. Nevertheless, further high-quality randomized controlled trials would be required to establish clinical evidence of PRP therapy.

Improved intervertebral bone union in ALIF rat model with porous hydroxyapatite/collagen combined with platelet-rich plasma

BACKGROUND CONTEXT

Platelet-rich plasma (PRP) can accelerate bone union in spinal fusion surgery with an autogenous bone graft. However, it is unclear whether bone union can be obtained by using artificial bone and PRP together in spinal interbody fusion surgery.

PURPOSE

This study aimed to determine whether interbody fusion can be achieved by transplanting porous hydroxyapatite/collagen(HAp/Col) which is an artificial bone material frequently used in spinal fusion surgery, together with PRP in the intervertebral disc space in rats.

STUDY DESIGN AND SETTING

A controlled laboratory study.

METHODS

A total of fourty 10-week old Sprague-Dawley rats were used in this study and assigned to three groups as follow: disc curettage only (control group, n=10), disc curettage + HAp/Col transplant (H group, n=10), and disc curettage + HAp/Col + PRP transplant (H+P group, n=10). The other 10 rats were sacrificed as blood donors for acquisition of PRP. Microcomputed tomography (μCT) examinations were performed to evaluate bone union, bone volume (BV), and bone mineral density (BMD) at 4, 8, and 12 weeks following surgery. Twelve weeks postoperatively, each group of three of L4-L5 spines was harvested to perform histological examination (hematoxylin & eosin stain) and the others were subjected to biomechanical testing (compression properties).

RESULTS

The platelet count in PRP was approximately 4.1 times greater than that in whole blood (260.6±26.2 × 10⁴ mg/dL and 64.3±2.9 × 10⁴ mg/dL in PRP and whole blood, respectively). All the L4-L5 lumbar discs were fused in the H+P group, whereas only one case was fused in the H group and none in the control group at 12 weeks after surgery. BV was significantly higher in the H+P group than in the H group or control groups (both p<.01), although BMD was not significantly different among the three groups. Upon histological analysis, mature bone formation was observed at the transplanted space in all cases in the H+P group, whereas fibrous tissue was observed at the location in the H and control groups. Regarding biomechanical properties, the ultimate load to failure was significantly higher in the H+P group than in the H group or control group (p=.021 and .013, respectively), although stiffness was not significantly different between the three groups.

CONCLUSION

The combination of porous HAp/Col and PRP at an appropriate concentration can promote bone union in the intervertebral disc space without using an autologous bone graft in the rat model. Bone tissue formation was histologically confirmed, and it was mechanically strong.

CLINICAL SIGNIFICANCE

This preclinical study showed that porous HAp/Col, when combined with PRP at an appropriate concentration, can induce bone union without autologous bone grafts. The results may eliminate the need for autologous bone collection for spinal fusion surgery in the future.

The Epidemiology of Platelet-Rich Plasma Injections From 2010 to 2020 in a Large US Commercial Insurance Claims Database: A Recent Update

INTRODUCTION

The popularity of platelet-rich plasma (PRP) injections for the treatment of orthopaedic conditions has grown markedly. We sought to better define the trends in the usage of orthopaedic PRP injections across an insured US population over the past decade.

METHODS

The PearlDiver M91Ortho commercial administrative claims database was queried for all patients receiving PRP injections for orthopaedic conditions from 2010 through the first quarter of 2020 (Q1.2020). Trends in PRP use, reimbursement charges, demographics, joints injected, and administering physicians were assessed over time and reported as year-over-year (YOY) changes.

RESULTS

Over the study period, 14,096 unique patients had 17,759 orthopaedic PRP injections. The number of PRP injections administered had a YOY increase of 7.1% (144 injections/year, 95% confidence interval [CI] = 89 to 199, Ptrend = 0.0009). A YOY increase of 895% was observed in total nonsurgical charges ($683,974/yr, 95% CI 441,504 to 926,444, Ptrend = 0.0009). The median age of PRP recipients increased (YOY change = +0.6 years, 95% CI 0.4 to 0.8, Ptrend = 0.0005). Injections to the elbow (YOY change = -0.8%, 95% CI -0.10% to [-0.06%], Ptrend = 0.005) and foot/ankle (YOY change = -1.0%, 95% CI -1.4% to [-0.06%], Ptrend = 0.002) decreased, whereas hip (YOY change = +0.4%, 95% CI 0.2% to 0.6%, Ptrend = 0.019), knee (YOY change = +0.9%, 95% CI 0.3% to 1.2%, Ptrend = 0.016), and spine (YOY change = +0.2%, 95% CI 0.0% to 0.4%, Ptrend = 0.033) injections increased. PRP injections given by sports medicine orthopaedic surgeons (YOY change = +0.8%, 95% CI 0.6% to 1.2%, Ptrend <0.0001) increased over time, whereas those by general orthopaedic surgeons decreased (YOY change = -0.9, 95% CI -1.2 to [-0.6%], Ptrend = 0.001).

CONCLUSION

PRP injections quadrupled in prevalence from 2010 to Q1.2020, with a projected increase in annual usage in this data set of 66% by 2030. As greater evidence-based indications for PRP use are identified, more specialists and insurance providers may consider expanding their involvement in this growing field.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Application of platelet-rich plasma in spinal surgery

With the aging of the population and changes in lifestyle, the incidence of spine-related diseases is increasing, which has become a major global public health problem; this results in a huge economic burden on the family and society. Spinal diseases and complications can lead to loss of motor, sensory, and autonomic functions. Therefore, it is necessary to identify effective treatment strategies. Currently, the treatment of spine-related diseases includes conservative, surgical, and minimally invasive interventional therapies. However, these treatment methods have several drawbacks such as drug tolerance and dependence, adjacent spondylosis, secondary surgery, infection, nerve injury, dural rupture, nonunion, and pseudoarthrosis. Further, it is more challenging to promote the regeneration of the interstitial disc and restore its biomechanical properties. Therefore, clinicians urgently need to identify methods that can limit disease progression or cure diseases at the etiological level. Platelet-rich plasma (PRP), a platelet-rich form of plasma extracted from venous blood, is a blood-derived product. Alpha granules contain a large number of cytokines, such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), epidermal growth factor, platelet factor 4 (PF-4), insulin-like growth factor-1 (IGF-1), and transforming growth factor-β (TGF-β). These growth factors allow stem cell proliferation and angiogenesis, promote bone regeneration, improve the local microenvironment, and enhance tissue regeneration capacity and functional recovery. This review describes the application of PRP in the treatment of spine-related diseases and discusses the clinical application of PRP in spinal surgery.

The efficacy of platelet-rich plasma applicated in spinal fusion surgery: A meta-analysis

Objective

The purpose of this meta-analysis is to evaluate the effect of the application of platelet-rich plasma (PRP) in spinal fusion surgery on the fusion rate of the spine.

Methods

A comprehensive search of the PubMed, Embase, Cochrane Library, and Science Direct databases was conducted to identify randomized control trials (RCTs) or observational cohort studies that evaluated the efficacy and safety of PRP in spinal fusion. Data on final fusion rate, changes in the visual analog scale (VAS), estimated blood loss (EBL), and operative time was collected from the eligible studies for meta-analysis. Patients were divided into PRP and non-PRP groups according to whether PRP was used during the spinal fusion procedure.

Results

According to the selection criteria, 4 randomized controlled trials and 8 cohort studies with 833 patients and 918 levels were included. The outcomes indicated that PRP application is associated with a lower fusion rat (OR = 0.62, 95% CI: (0.43, 0.89), P = 0.009) at final follow-up (>24 months). Subgroup analysis showed a lower rate of spinal fusion in the PRP group compared to the non-PRP group (OR = 0.35, 95% CI: (0.21, 0.58), P < 0.001) when spinal fusion was assessed using only anterior-posterior radiographs. When the bone graft material was a combination of autologous bone + artificial bone, the spinal fusion rate was lower in the PRP group than in the non-PRP group (OR = 0.34, 95% CI: (0.16, 0.71), P = 0.004). The PRP and non-PRP groups showed no significant differences in VAS changes at the 24th postoperative month (WMD = 0.36, 95% CI: (−0.37, 1.09), P = 0.33); Application of PRP does not reduce the estimated blood loss (WMD = −86.03, 95% CI: (−188.23, 16.17), P = 0.10). In terms of operation time, using PRP does not prolong operation time (WMD = −3.74, 95% CI: (−20.53, 13.04), P = 0.66).

Conclusion

Compared with bone graft fusion alone, PRP cannot increase the rate of spinal fusion. Inappropriate methods of spinal fusion assessment or mixing PRP with artificial/allograft bone may have been responsible for the lower rate of spinal fusion in the PRP group.

Systematic Review Registration

doi: 10.37766/inplasy2022.5.0055

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 role of Platelet Rich Plasma and other orthobiologics in bone healing and fracture management: A systematic review

BACKGROUND

Treatment of large bone defects and fracture healing complications (delayed and non-union) presents a substantial challenge for orthopaedic surgeons. Given that bone healing requires mechanical stability as well as a favourable biological microenvironment, orthobiologics such as Platelet-Rich Plasma (PRP) may have a significant clinical role to play.

AIMS

To perform a systematic review of the available literature to assess the clinical effect of PRP, with or without other orthobiologics, on bone healing.

METHOD

Two independent reviewers performed the literature search based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical studies of any evidence, assessing effect of PRP with or without other orthobiologics on bone healing, were included. A qualitative analysis was carried out on the clinical and radiological outcomes reported.

RESULT

27 articles with 1631 patients (mean age = 43.56, 57.1% male, mean follow-up = 17.27 months) were included in the qualitative. Of the 27 studies, 13 dealt with fracture complications (delayed or non-unions), 7 with acute fracture healing, 4 with tibial osteotomies and lengthening procedures and 3 with lumbar spine pathology. 18/27 studies showed a clinical benefit of PRP, 8/27 showed no significant effect, and 1/27 showed a worse outcome with PRP.

CONCLUSION

Our review suggests PRP may play a clinical role in bone healing but further randomised controlled trials (RCTs) using standardised outcomes should be performed to establish its efficacy.

Improved Posterolateral Lumbar Spinal Fusion Using a Biomimetic, Nanocomposite Scaffold Augmented by Autologous Platelet-Rich Plasma

Remodeling of the human bony skeleton is constantly occurring with up to 10% annual bone volume turnover from osteoclastic and osteoblastic activity. A shift toward resorption can result in osteoporosis and pathologic fractures, while a shift toward deposition is required after traumatic, or surgical injury. Spinal fusion represents one such state, requiring a substantial regenerative response to immobilize adjacent vertebrae through bony union. Autologous bone grafts were used extensively prior to the advent of advanced therapeutics incorporating exogenous growth factors and biomaterials. Besides cost constraints, these applications have demonstrated patient safety concerns. This study evaluated the regenerative ability of a nanostructured, magnesium-doped, hydroxyapatite/type I collagen scaffold (MHA/Coll) augmented by autologous platelet-rich plasma (PRP) in an orthotopic model of posterolateral lumbar spinal fusion. After bilateral decortication, rabbits received either the scaffold alone (Group 1) or scaffold with PRP (Group 2) to the anatomic right side. Bone regeneration and fusion success compared to internal control were assessed by DynaCT with 3-D reconstruction at 2, 4, and 6 weeks postoperatively followed by comparative osteogenic gene expression and representative histopathology. Both groups formed significantly more new bone volume than control, and Group 2 subjects produced significantly more trabecular and cortical bone than Group 1 subjects. Successful fusion was seen in one Group 1 animal (12.5%) and 6/8 Group 2 animals (75%). This enhanced effect by autologous PRP treatment appears to occur via astounding upregulation of key osteogenic genes. Both groups demonstrated significant gene upregulation compared to vertebral bone controls for all genes. Group 1 averaged 2.21-fold upregulation of RUNX2 gene, 3.20-fold upregulation of SPARC gene, and 3.67-fold upregulation of SPP1 gene. Depending on anatomical subgroup (cranial, mid, caudal scaffold portions), Group 2 had significantly higher average expression of all genes than both control and Group 1–RUNX2 (8.23–19.74 fold), SPARC (18.67–55.44 fold), and SPP1 (46.09–90.65 fold). Our data collectively demonstrate the osteoinductive nature of a nanostructured MHA/Coll scaffold, a beneficial effect of augmentation with autologous PRP, and an ability to achieve clinical fusion when applied together in an orthotopic model. This has implications both for future study and biomedical innovation of bone-forming therapeutics.

Platelet Concentrate In Lumbar Interbody Cage Fusion: A New Era of Modality Of Fusion

AIM: This was a prospective double-blinded randomized comparative study. Several authors have reported the efficacy of platelets derivatives for spinal union. However, the use of PRP and PRF for bone fusion with TLIF has not been fully explored. METHODS: Standard open TLIF surgery was performed on 80 patients, randomized in three groups, TLIF and local bone were used in 40 patients (control group) and TLIF, local bone, and PRP were used in 20 patients (PRP group) and PRF was used in 20 patients (PRF group). Radiological parameters were assessed by X-ray after 3 months post-operative to evaluate the position of the screws and cage migration and by CT scans at 6 months and 12 months postoperatively. Patients, surgeons, and post-surgical analysis were blinded. RESULTS: VAS scores for lower back pain and leg pain were statistically significant between the three groups preoperatively. The VAS scores of back pain improved after 12 months and were statistically significant (p < 0.001) and the VAS score of leg pain improved compared with preoperatively in the three groups during the 6- and 12-month follow-up postoperatively, however, the three groups, VAS scores for leg pain were not significantly different. After 1-year follow-up, significantly more patients achieved definite fusion, when implanted platelets derivatives compared with the control group, but with no significance regarding fusion rates. CONCLUSION: We advocated using platelet derivative as a fusion enhancer modality which is cost and time saving. It appears to be a complementary step that ensures better outcome for the patients.

Fragility Analysis of Statistically Significant Outcomes of Randomized Control Trials in Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The aim of this study was to assess the robustness of statistically significant outcomes from randomized control trials (RCTs) in spine surgery using Fragility Index (FI) which is a novel metric measuring the number of events upon which statistical significance of the outcome depends.

SUMMARY OF BACKGROUND DATA

Many trials in Spine surgery were characterized by fewer outcome events along with small sample size. FI helps us identify the robustness of the results from such studies with statistically significant dichotomous outcomes.

METHODS

We conducted independent and in duplicate, a systematic review of published RCTs in spine surgery from PubMed Central, Embase, and Cochrane Database. RCTs with 1:1 prospective study design and reporting statistically significant dichotomous primary or secondary outcomes were included. FI was calculated for each RCT and its correlation with various factors was analyzed.

RESULTS

Seventy trials met inclusion criteria with a median sample size of 133 (interquartile range [IQR]: 80-218) and median reported events per trial was 38 (IQR: 13-94). The median FI score was 2 (IQR: 0-5), which means if we switch two patients from nonevent to event, the statistical significance of the outcome is lost. The FI score was less than the number of patients lost to follow-up in 28 of 70 trials. The FI score was found to positively correlated with sample size (r = 0.431, P = 0.001), total number of outcome events (r = 0.305, P = 0.01) while negatively correlated with P value (r = -0.392, P = 0.001). Funding, journal impact-factor, risk of bias domains, and year of publication did not have a significant correlation.

CONCLUSION

Statistically significant dichotomous outcomes reported in spine surgery RCTs are more often fragile and outcomes of the patients lost to follow-up could have changed the significance of results and hence it needs caution before transcending their results into clinical application. The addition of FI in routine reporting of RCTs would guide readers on the robustness of the statistical significance of outcomes. RCTs with FI ≥5 without any patient lost to follow-up can be considered to have clinically robust results.Level of Evidence: 1.

Platelet Rich Plasma in Orthopedic Surgical Medicine

There is a global interest in optimizing post-surgical tissue repair strategies, leading to better patient outcomes and fewer complications, most ideally with reduced overall cost. In this regard, in recent years, the interest in autologous biological treatments in orthopedic surgery and sports medicine has increased greatly, and the addition of platelet-rich plasma (PRP) to the surgical armamentarium is of particular note. Unfortunately, the number of PRP preparation devices has also grown immensely over the recent decades, raising meaningful concern for the considerable variation in the qualities of currently available PRP preparations. The lack of consensus on the standardization of PRP preparation and of agreement on condition specific PRP formulations is largely responsible for the sometimes contradictory outcomes in the literature. Furthermore, the full potential of PRP technology, the concept of individualized treatment protocols based on bioformulation options, and platelet dosing, angiogenesis, and antimicrobial and painkilling effects of PRP relevant to orthopedic surgery have rarely been addressed. In this review, we will discuss recent developments regarding PRP preparations and potential therapeutic effects. Additionally, we present a synopsis of several published data regarding PRP applications in orthopedic surgery for treating tendon injuries, inducing bone repair, strengthening spinal fusion outcomes, and supporting major joint replacements.

The effect of platelet-rich plasma on the fusion rate and clinical outcome of spinal fusion surgery: A systematic review and meta-analysis

BACKGROUND

Platelet-rich plasma (PRP) is widely used in many orthopedic surgeries and spinal disease treatments; however, the effect of PRP on spinal fusion remains controversial.

QUESTIONS/PURPOSES

To assess the fusion rate and clinical results of PRP compared with non-PRP administration in the treatment of spinal fusion with regard to decreasing pain and improving healing and function.

PATIENTS AND METHODS

Studies comparing PRP to non-PRP treatment with respect to the fusion rate and clinical outcome in patients who underwent spinal fusion surgery were included.

RESULT

Three randomized controlled trials (RCTs) and 7 prospective cohort studies were identified. The spinal fusion rate was not significantly different between the groups in all RCTs or cohort studies at the final follow-up. In comparison, PRP significantly reduced pain after surgery as evaluated in the RCT analysis and the complication rate did not differ significantly between the two groups.

CONCLUSION

According to the available studies, PRP does not contribute to the union rate, relieve pain or increase the complication rate in spinal fusion surgery. As clinical heterogeneity exists in these studies, further large, well-designed RCTs that focus on the standard assessment of PRP are needed.

The impact of platelet-rich plasma on postoperative outcomes after spinal fusion: a systematic review and meta-analysis

OBJECTIVE

Platelet-rich plasma (PRP) is a biological agent obtained by centrifuging a sample of blood and retrieving a high concentration of platelets and plasma components. The concentrate is then stimulated for platelet secretion of various growth factors and cytokines. Although it is not widely used in clinical practice, its role in augmenting bony union among patients undergoing spinal fusion has been assessed in several clinical studies. The objective of this study was to perform a systematic review and meta-analysis of the existing literature to determine the efficacy of PRP use in spinal fusion procedures.

METHODS

A comprehensive literature search was conducted using PubMed, Scopus, and EMBASE for studies from all available dates. From eligible studies, data regarding the fusion rate and method of assessing fusion, estimated blood loss (EBL), and baseline and final visual analog scale (VAS) scores were collected as the primary outcomes of interest. Patients were grouped by those undergoing spinal fusion with PRP and bone graft (PRP group) and those only with bone graft (graft-only group).

RESULTS

The literature search resulted in 207 articles. Forty-five full-text articles were screened, of which 11 studies were included, resulting in a meta-analysis including 741 patients. Patients without PRP were more likely to have a successful fusion at the last follow-up compared with those with PRP in their bone grafts (OR 0.53, 95% CI 0.34-0.84; p = 0.006). There was no statistically significant difference with regard to change in VAS scores (OR 0.00, 95% CI -2.84 to 2.84; p > 0.99) or change in EBL (OR 3.67, 95% CI -67.13-74.48; p = 0.92) between the groups.

CONCLUSIONS

This study found that the additional use of PRP was not associated with any significant improvement in patient-reported outcomes and was actually found to be associated with lower fusion rates compared with standard grafting techniques. Thus, PRP may have a limited role in augmenting spinal fusion.

Role of Platelet-Rich Plasma in Spinal Fusion Surgery: Systematic Review and Meta-Analysis

Background

Platelet-rich plasma (PRP) has been used very successfully in enhancing bone fusion in animal experiments. Also, the efficaciousness of PRP in other specialties of medicine such as dentistry, dermatology ophthalmology, and sports medicine is well documented. But the use of PRP to augment bone fusion after spinal surgery in humans is still controversial. We conducted a meta-analysis to determine the role of PRP in enhancing spinal fusion by fastening the rate of new bone formation and decreasing pain after spinal surgery in humans.

Methods

We searched PubMed, EMBASE, and the Cochrane Library studies that compared PRP versus control in enhancing spinal fusion after deformity correction.

Results

Five retrospective studies with 253 participants and nine prospective cohort studies with 460 participants were identified. The bone fusion rate was excellent for studies that used a high platelet concentration in PRP relative to control (odds ratio (OR) = 4.35, 95% confidence interval (CI) (2.13, 8.83), and P < 0.05) while bone fusion was poor to studies that used a low concentrate of platelet in PRP relative to control. The rate of new bone formation was high in the PRP group compared to the control group with the mean difference in Hounsfield unit (HU) 144.91 (95% CI (80.63, 209.18), P < 0.05). Time to bone fusion was short in the PRP group during the first six months of surgery relative to the control group with a mean difference of −2.03 (95% CI (−2.35, −1.7); P < 0.05). No difference was found in pain reduction by visual analog score (VAS) between the PRP group and control.

Conclusion

PRP facilitates new bone formation and bone fusion with a minimum concentration of the growth factor 5 times that of the peripheral blood. PRP stimulatory effects are not continuous and are very effective within six months of implantation.

Efficacy of Using Platelet-Rich Plasma in Spinal Fusion Surgery-A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-Compliant Meta-Analysis

BACKGROUND

Platelet-rich plasma (PRP) has been frequently used to enhance bone regeneration. A meta-analysis was conducted to systematically assess the fusion rate and pain relief of applying PRP during spinal fusion surgery.

METHODS

Studies investigating spinal fusion surgery combined with PRP were retrieved from Medline and the Web of Science in accordance with the inclusion and exclusion criteria. A quality evaluation was conducted using the Cochrane collaboration tool for randomized controlled trials and the Newcastle-Ottawa scale quality assessment for cohort trials. Statistical analysis was performed using RevMan, version 5.3.

RESULTS

A total of 12 studies, including 3 randomized controlled trials and 9 cohort studies, with 661 patients, were included in the present meta-analysis. The mean age was 52.3 ± 8.0 years. Overall, the pooled results demonstrated that the differences in the fusion rates between the PRP and non-PRP treatment groups were not statistically significant. The risk ratio was 1.01 (95% confidence interval, 0.95-1.06; P = 0.83). Also, no significant difference in pain relief measured using the visual analog scale was found between the 2 groups. The mean difference was -0.08 (95% confidence interval, -0.26 to 0.11; P = 0.42).

CONCLUSIONS

Adding PRP did not increase the fusion rates from spinal fusion surgery. In addition, no significant difference was found in pain relief between the PRP and non-PRP treatment groups.

Efficacy of platelet-rich plasma in posterior lumbar interbody fusion: systematic review and meta-analysis

INTRODUCTION

We have conducted a systematic review and meta-analysis that aims to compare outcomes (pain VAS, fusion and adverse event) of PRP and placebo after posterolateral lumbar fusion (PLF) surgery.

MATERIALS AND METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant studies were identified from Medline and Scopus from inception to September 16, 2019 that reported visual analog scale back pain, postoperative complications and fusions of either group.

RESULTS

In a total of seven studies, two, two, three studies were RCT, prospective and retrospective studies, respectively. Overall, there were 270 patients (150 in the PRP group and 149 in the placebo group). Three, three, four, three, two, seven and four studies were reported for pain VAS back in 3 months, 6 months, 12 months, 24 months, period of fusion, postoperative fusion and adverse events, respectively. The unstandardized mean difference (UMD) VAS back in 3, 6, 6 and 24 months was - 0.41 (95% CI - 0.87, 0.05) score, - 0.97 (95% CI - 1.68, - 0.27) score, - 0.33 (95% CI - 0.61, - 0.59) score, - 0.19 (95% CI - 1.00, 0.62) scores lower than placebo after posterolateral lumbar fusion (PLF) patients. The UMD period of bone union were - 1.62 (95% CI - 1.85, - 1.39) months faster than placebo after PLF patients. A total of seven and four studies were reported fusion and adverse events between PRP and placebo group. No significant differences were noted for fusion and adverse events with the pooled RR of 1.03 (95% CI 0.48, 1.80) and 0.95 (95% CI 0.14, 6.56).

CONCLUSIONS

PRP with autologous bone graft had lower back pain and faster bone union time than bone graft alone. While, there have no difference in fusion rate and adverse events in both groups. Larger, prospective randomized controlled studies are needed to confirm these findings as the current literature is still insufficient. Further research including cost of operation, postoperative function and satisfaction, quality of life and cost-efficacy analysis is required to determine whether the PRP with autologous bone graft is superior to bone graft alone or not.

LEVEL OF EVIDENCE

Level II.

Freeze-Dried Platelet-Rich Plasma Induces Osteoblast Proliferation via Platelet-Derived Growth Factor Receptor-Mediated Signal Transduction

Study Design

Controlled laboratory study.

Purpose

This study aimed to evaluate the in vitro pharmacological activity of growth factors (GFs) in freeze-dried platelet-rich plasma (FD-PRP) after storage for 4 weeks.

Overview of Literature

Freshly prepared PRP is a rich source of many GFs. We reported that FD-PRP stored for 8 weeks accelerated bone union in a rat posterolateral fusion model equally well as fresh-PRP. However, the pharmacological activity of FD-PRP after long-term storage has not been shown in vitro.

Methods

Immediately after preparation, as well as 4 weeks after freeze-dried storage, the platelet count was measured. Human osteoblasts were treated with fresh-PRP and FD-PRP, respectively. Western blotting was used to assess the phosphorylation of the platelet-derived growth factor (PDGF) receptor (PDGFR) and its downstream target, extracellular signal-regulated kinase (ERK). The proliferation rates of osteoblasts were investigated by immunocytochemistry and MTT cell viability assays. Furthermore, we used western blotting to evaluate the effect of PDGFR knockdown on the phosphorylation of ERK stimulated with fresh-PRP and FD-PRP.

Results

Platelet counts in both the fresh-PRP and FD-PRP samples were approximately 10-fold higher than in peripheral blood samples. The phosphorylation and activation of the PDGFR and ERK were evenly induced by fresh-PRP and FD-PRP stimulation. Both freshPRP and FD-PRP significantly induced osteoblast proliferation in MTT cell viability assays. Furthermore, osteoblast PDGFR knockdown attenuated the downstream ERK activation by fresh PRP and FD-PRP.

Conclusions

We demonstrated the pharmacological activity of PDGF in FD-PRP in vitro after 4 weeks of storage.

Platelet-rich plasma for the spinal fusion

There has been a wide interest in using platelet-rich plasma (PRP) as a therapeutic agent to enhance spinal fusion. There are two review articles based only on clinical studies regarding the effect of PRP on spinal fusion. However, with regard to both animal model studies and clinical studies, there is no review studies regarding its effect on spinal fusion and no review studies focusing on the platelet count and the concentration of the growth factor in the PRP. The purpose is to review the literatures about the effect of PRP on spinal fusion according to the animal model studies and clinical studies, focusing on the effect of the platelet count and the concentration of the growth factor in the PRP. A PubMed search was performed for English-language articles. We identified 20 articles regarding the effect of PRP on fusion in animal model studies and clinical studies, of which 16 articles met the study criteria of case-control studies or prospective randomized studies for the spinal fusion. The articles were categorized into small-sized animal model, middle-sized animal model, and clinical studies. Studies have shown both beneficial and inhibitory effects. The conclusion that PRP has the stimulating effect on spinal fusion was not reached. However, PRP might promote the human spinal fusion if the platelet count or the concentration of growth factors in the PRP increases.

Positive effect on spinal fusion by the combination of platelet-rich plasma and collagen-mineral scaffold using lumbar posterolateral fusion model in rats

Background

Platelet-rich plasma (PRP) is autologous in origin and contains a high concentration of platelets which is a source of various growth factors. Previous studies have suggested that PRP has a positive effect in accelerating fusion by an autologous bone graft in a lumbar fusion. The role of PRP on artificial bone grafts in spinal fusion remains controversial. In this study, positive effect on spinal fusion by PRP was hypothesized; in vitro and in vivo studies were designed to test this hypothesis.

Methods

PRP was produced from peripheral blood of Sprague-Dawley (SD) rats. A lumbar posterolateral arthrodesis model was used to test the efficacy of PRP on spinal fusion. Thirty SD rats were divided into three groups by different implants: the PRP group, PRP plus collagen-mineral carrier; the platelet-poor plasma (PPP) group, PPP plus collagen-mineral carrier; and the control group, collagen-mineral only. Spinal fusion was examined using plain radiographs, micro-computed tomography (micro-CT), manual palpation, and histological analysis. The fusion rate by micro-CT and that by manual palpation in groups were compared.

Results

In the micro-CT results, 16 fused segments were observed in the PRP group (80%, 16/20), 2 in the PPP group (10%, 2/20), and 2 in the control group (10%, 2/20). The fusion rate, determined by manual palpation, was 60% (6/10) in the PRP group, 0% (0/10) in the PPP group, and 0% (0/10) in the control group. Histology showed that the PRP group had more new bone and matured marrow formation.

Conclusions

The results of this study demonstrated that PRP on an artificial bone carrier had positive effects on lumbar spinal fusion in rats. In the future, this composite could be potentially used as a bone graft in humans.

Single-center, consecutive series study of the use of a novel platelet-rich fibrin matrix (PRFM) and beta-tricalcium phosphate in posterolateral lumbar fusion

PURPOSE

To evaluate the radiographic and clinical outcomes of the combination of platelet-rich fibrin matrix (PRFM) with beta-tricalcium phosphate (β-TCP) and bone marrow aspirate (BMA) as a graft alternative in posterolateral lumbar fusion procedures.

METHODS

Researchers evaluated 50 consecutive patients undergoing one-level to three-level posterolateral lumbar fusion procedures, resulting in a total of 66 operated levels. The primary outcome was evidence of radiographic fusion at 1-year follow-up, assessed by three independent evaluators using the Lenke scoring system. Secondary outcomes included back and leg VAS scores, incidence of reoperations and complications, return-to-work status, and opioid use.

RESULTS

At 1-year follow-up, radiographic fusion was observed in 92.4% (61/66) of operated levels. There was significant improvement in VAS scores for both back and leg pain (p < 0.05). Compared to baseline figures, the number of patients using opioid analgesics at 12-months decreased by 38%. The majority (31/50) of patients were retired, yet 68% of employed patients (n = 19) were able to return to work. No surgical site infections were noted, and no revision surgery at the operated level was required.

CONCLUSIONS

This is the first report to analyze the combination of PRFM with β-TCP and BMA for PLF procedures. Our results indicate a rate of fusion similar to those reported using iliac crest bone graft (ICBG), while avoiding donor site morbidity related to ICBG harvesting such as hematoma, pain, and infection. These slides can be retrieved under Electronic Supplementary Material.