Patellar tendon healing with platelet-rich plasma: a prospective randomized controlled trial

Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study

BACKGROUND

There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation.

METHODS

Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically.

RESULTS

The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections.

CONCLUSIONS

PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

Platelet-rich plasma augmentation in anterior cruciate ligament reconstruction: Evidence is still too scattered. A scoping review of randomised controlled trials

PURPOSE

Platelet-rich plasma (PRP) augmentation has been proposed to improve the results of anterior cruciate ligament reconstruction (ACLR). The present study aims to quantify the available evidence to support the use of PRP as biological augmentation in ACLR surgery.

METHODS

A systematic literature search was conducted on the PubMed, Cochrane, Web of Science and Embase databases on 10 March 2023. Inclusion criteria were randomised controlled trials (RCTs), written in English, addressing PRP augmentation in ACLR surgery, with no time limitation. A scoping review was performed to map the body of literature by examining the evidence related to specific aspects of patients' treatment and evaluation. Risk of bias evaluation was performed with the Cochrane risk-of-bias tool for randomised trials Version 2 (RoB 2), while the quality assessment was performed with the use of the Coleman Score.

RESULTS

Out of 983 articles retrieved, 23 RCTs on 943 knees were included in this scoping review. PRP was administered in a liquid form in nine studies and clotted in 11 studies, while in three studies both liquid and clotted PRP were used. Hamstring auto/allografts were used in 14 studies, patellar tendon auto/allografts were used in eight studies and one study described ACLR with peroneus longus allografts. The map of the evidence documented high heterogeneity also in terms of surgical technique, objective and subjective outcome measures and radiological assessment, as well as follow-up times ranging from 1 day to 2 years, with virtually no overlapping data among studies neither in terms of treatments nor evaluations. Risk of bias evaluation showed an overall low quality of the included studies.

CONCLUSIONS

The available literature addressing PRP augmentation in ACLR is largely scattered. PRP was produced and applied following different procedures, and high variability was detected across the included studies for every aspect of ACLR surgery and evaluation. Currently, a meaningful comparison of the available studies is not possible as the quantification of the literature results is biased by their heterogeneity. Future studies should provide more standardisation to investigate the benefits of biological augmentation in ACL surgery and confirm the promising yet weak evidence of PRP potential as well as the most suitable application modality, before routine use in clinical practice.

LEVEL OF EVIDENCE

Levels I and II, scoping review.

Acute Patellar Tendon Ruptures: An Update on Management

Patellar tendon ruptures can be debilitating injuries. When incomplete, partial tears can be managed nonsurgically with immobilization and progressive rehabilitation. Although complete ruptures remain a relatively uncommon injury, they portend a high level of morbidity. Ruptures typically result from an acute mechanical overload to the extensor mechanism, such as with forced quadriceps contraction and knee flexion. However, chronically degenerated tendons are also predisposed to failure from low-energy injuries. Diagnosis can often be made clinically with recognition of a palpable defect to the tendon, localized patellar tendon tenderness, and inability to actively extend the knee. Diagnosis and surgical planning can be established with radiograph, ultrasonography, or magnetic resonance imaging. Surgical repair is the mainstay of treatment, and there have been many recent advances in repair technique, optimal reconstruction strategies, and supplemental fixation. Time to surgery for complete tears remains the most important prognosticator for success. Direct primary repair can be completed with transosseous tunnels, suture anchor repair, or end-to-end repair. Tendon reconstruction can be achieved with or without mechanical or biologic augments. Rehabilitation programs vary in specifics, but return to sport can be expected by 6 months postoperatively.

Most Publications Regarding Platelet-Rich Plasma Use in the Knee Are From Asia, Investigate Injection for Osteoarthritis, and Show Outcome Improvement: A Scoping Review

PURPOSE

To evaluate and synthesize the available literature related to platelet-rich plasma (PRP) treatment of knee pathologies and to provide recommendations to inform future research in the field.

METHODS

PubMed, CINAHL, and Scopus databases were queried on October 6, 2023. All identified citations were collated and uploaded into Covidence for screening and data extraction. Studies were included if they were human studies published in English with adult cohorts that received PRP as a procedural injection or surgical augmentation for knee pathologies with patient-reported outcome measures (PROMs) and level of evidence Levels I-IV.

RESULTS

Our search yielded 2,615 studies, of which 155 studies from 2006 to 2023 met the inclusion criteria. Median follow-up was 9 months (±11.2 months). Most studies (75.5%) characterized the leukocyte content of PRP, although most studies (86%) did not use a comprehensive classification scheme. In addition, most studies were from Asia (50%) and Europe (32%) and were from a single center (96%). In terms of treatment, 74% of studies examined PRP as a procedural injection, whereas 26% examined PRP as an augmentation. Most studies (68%) examined treatment of knee osteoarthritis. Many studies (83%) documented significant improvements in PROMs, including 93% of Level III/IV evidence studies and 72% of Level I/II evidence studies, although most studies (70%) failed to include minimal clinically important difference values. The visual analog scale was the most-used PROM (58% of studies), whereas the Short Form Health Survey 36-item was the least-used PROM (5% of studies).

CONCLUSIONS

Most published investigations of knee PRP are performed in Asia, investigate procedural injection for osteoarthritis, and show significant outcome improvements. In addition, this review highlights the need for better classification of PRP formulations.

LEVEL OF EVIDENCE

Level IV, scoping Review of level I-IV studies.

The Influence of Platelet-Rich Fibrin on the Healing of Bone Defects after Harvesting Bone-Patellar Tendon-Bone Grafts

Background and Objectives: A bone-patellar tendon-bone (BTB) autograft in anterior cruciate ligament reconstruction (ACLR) is still considered the gold standard among many orthopedic surgeons, despite anterior knee pain and kneeling pain being associated with bone defects at the harvest site. Bioregenerative products could be used to treat these defects, perhaps improving both the postoperative discomfort and the overall reconstruction. Materials and methods: During a year-long period, 40 patients were enrolled in a pilot study and divided into a study group, in which bone defects were filled with Vivostat® PRF (platelet-rich fibrin), and a standard group, in which bone defects were not filled. The main outcome was a decrease in the height and width of the bone defects, as determined by magnetic resonance imaging on the control exams during the one-year follow-up. The secondary outcomes included an evaluation of kneeling pain, measured with a visual analog scale (VAS), and an evaluation of the subjective knee scores. Results: The application of Vivostat® PRF resulted in a more statistically significant reduction in the width of the defect compared with that of the standard group, especially at 8 and 12 months post operation (p < 0.05). Eight months following the surgery, the study group's anterior knee pain intensity during kneeling was statistically considerably lower than that of the standard group (p < 0.05), and the statistical difference was even more obvious (p < 0.01) at the last follow-up. Each control examination saw a significant decrease in pain intensity in both the groups, with the values at each exam being lower than those from the prior exam (p < 0.01). A comparison of subjective functional test results 12 months post operation with the preoperative ones did not prove a statistically significant difference between the groups. Conclusions: The use of Vivostat® PRF reduces kneeling pain and accelerates the narrowing of bone defects after ACLR with a BTB graft, but without confirmation of its influence on the subjective knee score.

Influence of platelet-rich plasma (PRP) analogues on healing and clinical outcomes following anterior cruciate ligament (ACL) reconstructive surgery: a systematic review

PURPOSE

To systematically review the effect of PRP on healing (vascularization, inflammation and ligamentization) and clinical outcomes (pain, knee function and stability) in patients undergoing ACL reconstruction and compare the preparation and application of PRP.

METHODS

Independent systematic searches of online databases (Medline, Embase and Web of Science) were conducted following PRISMA guidelines (final search 10th July 2021). Studies were screened against inclusion criteria and risk of bias assessed using Critical appraisal skills programme (CASP) Randomised controlled trial (RCT) checklist. Independent data extraction preceded narrative analysis.

RESULTS

13 RCTs were included. The methods of PRP collection and application were varied. Significant early increases in rate of ligamentization and vascularisation were observed alongside early decreases in inflammation. No significant results were achieved in the later stages of the healing process. Significantly improved pain and knee function was found but no consensus reached.

CONCLUSIONS

PRP influences healing through early vascularisation, culminating in higher rates of ligamentization. Long-term effects were not demonstrated suggesting the influence of PRP is limited. No consensus was reached on the impact of PRP on pain, knee stability and resultant knee function, providing avenues for further research. Subsequent investigations could incorporate multiple doses over time, more frequent observation and comparisons of different forms of PRP. The lack of standardisation of PRP collection and application techniques makes comparison difficult. Due to considerable heterogeneity, (I² > 50%), a formal meta-analysis was not possible highlighting the need for further high quality RCTs to assess the effectiveness of PRP. The biasing towards young males highlights the need for a more diverse range of participants to make the study more applicable to the general population.

TRAIL REGISTRATION

CRD42021242078CRD, 15th March 2021, retrospectively registered.

Effectiveness of Platelet-Rich Plasma in Anterior Cruciate Ligament Reconstruction: A Systematic Review of Randomized Controlled Trials

This study aimed to identify the effectiveness of platelet-rich plasma (PRP) for patients operated with anterior cruciate ligament reconstruction (ACLR). Databases of PubMed, Embase, and CENTRAL were independently retrieved by two authors, for identifying the eligible randomized controlled trials (RCTs) comparing the clinical and imaging outcomes of ACL reconstructed patients augmented with or without PRP. The Cochrane Collaboration tool was utilized to assess the risk of bias of the included trials. We qualitatively synthesized the outcomes include the image evaluations on the healing of bone tunnels, graft remodeling, donor site healing and tunnel widening, and clinical evaluations on knee stability and function, pain symptom by visual analogue scale (VAS), inflammatory parameters and so on. A total of 16 RCTs, including 1025 patients, were included for eligibility. Generally, the included studies were of low risk of bias, but the conducting of allocation concealment was not clearly described in many studies. Three imaging techniques, including MRI, CT and ultrasound, were selected in these trials. Significant improvement on graft remodeling, bone tunnel healing, harvest site healing and bone tunnel diameters were demonstrated in one of five (20.0%), three of five (60.0%), two of four (50.0%) and one of five (20.0%) studies respectively, for PRP group. Various clinical outcomes, such as IKDC score, Lysholm score, Tegner score, knee anteroposterior and rotational laxity, range of motion and VAS, could not be improved with PRP application. The PRP is associated with very limited role in improving knee outcomes following ACLR, and there is no indication for PRP procedures in ACLR at this stage.

Common Medications Which Should Be Stopped Prior to Platelet-Rich Plasma Injection

Osteoarthritis (OA) is an extremely prevalent joint condition in the United States, affecting over 30 million people [...]

Lower Extremity Muscle Injuries in the Overhead Athlete

PURPOSE OF REVIEW

Lower extremity (LE) injuries are a common source of disability and time-loss for overhead athletes, and muscles have been found to be the predominant soft tissue structure affected. The current review highlights the orthopaedic literature examining lower extremity muscle injuries in overhead athletes in regard to epidemiology, diagnosis, and conventional and emerging treatment measures.

RECENT FINDINGS

The hamstring muscles have been found to be the most commonly injured lower extremity muscle group in professional baseball, followed by the adductors, quadriceps, iliopsoas, and gastrocnemius-soleus complex. Strains and contusions comprise over 90% of these muscle injuries. Various advanced imaging grading systems have been developed to help characterize the nature of a muscle injury, although a clear and consistent prognostic utility of these systems is still unclear. The vast majority of lower extremity muscle injuries in overhead athletes are managed nonoperatively, and there is promising data on the use of emerging treatments such as platelet-rich plasma and blood flow restriction therapy. Lower extremity muscle injuries-often referred to as strains-are a relatively common issue in high-demand overhead athletes and can be a significant source of time-loss. Within baseball, position players are affected far more often than pitchers, and sprinting and fielding are the most common activities leading to strains. Magnetic resonance imaging (MRI) is considered the gold standard imaging modality to evaluate these muscle injuries and will allow for a detailed assessment of tissue damage. Nonetheless, return-to-play is often dictated by a given athlete's progression through a nonoperative rehabilitation protocol, with surgical intervention reserved for less common, select injury patterns.

A Systematic Review on the Effect of Common Medications on Platelet Count and Function: Which Medications Should Be Stopped Before Getting a Platelet-Rich Plasma Injection?

Background:

Platelet-rich plasma (PRP) exerts its effect through the release of growth factors and cytokines from the platelet concentrate. Certain medications may affect platelet count or function, resulting in decreased efficacy of PRP injections.

Purpose:

To systematically review the literature regarding common medications and their effects on platelets to establish guidelines for which medications should be stopped before obtaining a PRP injection.

Study Design:

Systematic review; Level of evidence, 2.

Methods:

This review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A search for studies assessing the effect of common medications on platelet count or platelet function was performed of the PubMed, Cochrane Library, Web of Science, and OpenGrey databases. Inclusion criteria were as follows: drug studied was aspirin, acetaminophen, a nonsteroidal anti-inflammatory drug (NSAID), a statin, or gabapentin; human participants; and article in the English language. Risk of bias was assessed using the Cochrane Risk of Bias tool and the Risk of Bias in Non-randomised Studies—of Interventions tool.

Results:

A total of 1711 studies were identified through the initial search, with 20 studies meeting all inclusion criteria. No studies involving gabapentin met all inclusion criteria. Patients treated with aspirin (268 patients) or acetaminophen (13 patients) showed a significant decrease in platelet aggregation. Statin therapy (73 patients) did not result in a significant decrease in platelet aggregation. Patients who took NSAIDs (172 patients) demonstrated significantly decreased platelet aggregation only when treated with nonselective formulations. Those treated with cyclooxygenase (COX)-2–selective NSAIDs showed no significant difference in platelet aggregation. Treatment with aspirin, acetaminophen, statins, or NSAIDs did not lead to a significant decrease in platelet count.

Conclusion:

Aspirin, acetaminophen, and nonselective NSAIDs should be considered for suspension before a PRP injection because of their potential to diminish the effects of the injection. COX-2–selective NSAIDs and statins do not need to be withheld before a PRP injection.

Effects of Platelet-Rich Plasma on Clinical Outcomes After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

Background:

Many studies have documented the use of platelet-rich plasma (PRP) alongside anterior cruciate ligament (ACL) reconstruction (ACLR) in the management of ACL injury, but evidence on the benefits of PRP in improving the clinical outcomes of ACLR is inconsistent.

Purpose:

To help in our understanding, we undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) that evaluated the effects of PRP on patient-reported functional scores, the clinical assessments of knee function and structure, and complications.

Study Design:

Systematic review; Level of evidence, 1.

Methods:

We searched 9 online databases for RCTs published in English or Chinese that examined the effects of PRP on ACLR. The primary outcome measures were visual analog scale (VAS) for pain and International Knee Documentation Committee (IKDC) scores. The secondary outcomes included KT-1000 arthrometer, pivot-shift test, Lysholm and Tegner scores, tunnel widening, graft characterization, and complications. Subgroup analyses were performed according to time of assessments. Fixed- and random-effects models were selected for data analysis.

Results:

A total of 14 studies were included. When PRP was injected to graft tunnels, the pooled VAS scores of the 2 groups were similar (P = .31), and the subgroup analysis found that VAS and IKDC only improved at 3 months postoperatively (P = .0003 and P < .00001, respectively). When PRP was used at the bone–patellar tendon–bone harvest sites, VAS was decreased in the first 6 months postoperatively (P < .00001), whereas IKDC score was not remarkably different (P = .07). After PRP injection, Lysholm scores at 3 months postoperatively was different between the 2 groups (P < .00001), but the Tegner scores (P = .86), KT-1000 measurements (P = .12), the positive rate of pivot-shift test (P = .64), the enlargement of tunnels (femoral, P = .91; tibial, P = .80), and the characterization of grafts (P = .05) were not different. No difference in complications was found in either group.

Conclusion:

PRP applied alongside ACLR could reduce postoperative pain and improve knee function in the short and medium terms but is ineffective in the long term. PRP does not improve knee stability and the enlargement of tunnels and does not accelerate the healing of grafts. Further studies would be required.

Clinical Use of Platelet-Rich Plasma to Promote Tendon-Bone Healing and Graft Maturation in Anterior Cruciate Ligament Reconstruction-A Randomized Controlled Study

BACKGROUND

We investigated the effect of platelet-rich plasma (PRP) on tendon-bone healing and intra-articular graft (IAG) maturation after anterior cruciate ligament (ACL) reconstruction.

METHODS

In this prospective randomized controlled study, 60 patients with ruptured ACLs were divided one-to-one into two groups (study and control). Patients were treated using single-bundle autologous hamstring autografts. Only patients in the study group were administered PRP. Knee function (pre-operative and three-, six-, and 12-month post-operative Lysholm activity, Tegner and International Knee Documentation Committee scores, femoral tunnel (FT) and tibial tunnel (TT) diameters measured with computed tomography (post-operative follow-up at 4 days and at 12 months), and magnetic resonance imaging signal/noise quotients of the IAG and graft in the FT (at 12 months) were used to evaluate tendon-bone healing and graft maturation.

RESULTS

Patients' knee function scores improved after ACL reconstruction, but there were no significant differences between groups. At 12 months, FT (study, 8.88 ± 1.46 mm; control, 8.42 ± 2.75 mm) and TT (study, 9.50 ± 1.07 mm; control, 9.99 ± 1.91 mm) diameters were larger than FT (study, 6.91 ± 0.74 mm; control, 7.30 ± 1.17 mm) and TT (study, 9.31 ± 0.83 mm; control, 9.36 ± 0.88 mm) diameters at 4 days; however, differences between groups were not significant (FT, P = 0.67; TT, P = 0.52). There were no significant differences between groups for signal/noise quotients of the IAG (study, 1.38 ± 0.70; control, 2.01 ± 0.62; P = 0.06) and FT-portion of the graft (study, 2.39 ± 1.22; control, 2.46 ± 0.83; P = 0.89).

CONCLUSION

PRP had no significant effect on reducing bone tunnel widening, accelerating tendon-bone healing, or improving knee function; however, PRP may improve IAG maturation.

TRIAL REGISTRATION

Our study was first registered at Clinicaltrials.gov with registration No. NCT04659447 on 12/09/2020.

Platelet rich plasma versus glucocorticoid for plantar fasciitis: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Plantar fasciitis (PF) is the most common cause of heel pain in adult. There are a variety of ways to treat PF, but these treatments have varied result in their effectiveness, and exist different degrees of limitations. At present, clinical studies focus on the effect of glucocorticoid (GC) and platelet rich plasma (PRP) in the treatment of PF, but there is a lack of systematic evaluation PRP and GC's clinical effect towards PF. This study aims to evaluate the long-term efficacy of GCs and PRP in the treatment of PF by means of meta-analysis.

METHODS

The literature of a randomized controlled clinical trial of PRP in the treatment of plantantifasciitis was searched on the Internet. Retrieve 7 databases. EndNote X9 software was used for document management. The Jadad scale was used to score the literature. Risk assessment of the literature was conducted according to Cochrane's systematic evaluation manual 5.0. RevMan5.3 software was used for literature risk bias analysis. Stata12.0 software is used for sensitivity analysis.

RESULTS

This study will provide effective evidence-based evidence for the long-term efficacy of PRP and GC in treating PF.

CONCLUSION

A systematic review and meta-analysis were conducted for the comparison of the long-term effect of PRP and GC on plantar fascia in the treatment of PF.

Effect of Activated Platelet-Rich Plasma on Chondrogenic Differentiation of Rabbit Bone Marrow-Derived Mesenchymal Stem Cells

We aimed to evaluate the effect of activated platelet-rich plasma (PRP) on proliferation and chondrogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Six mature male rabbits were included in this study. PRP was obtained by two-step centrifugation from whole blood, and it was activated using CaCl₂ solution. BMSCs were isolated and proliferated from bone marrow of rabbits and characterized by flow cytometry. Passage 3 BMSCs were cultured in high-glucose Dulbecco's modified Eagle's medium (HG-DMEM) with the four different compositions for consecutive 7 days, including 10% fetal bovine serum, 5% PRP, 10% PRP, and 15% PRP. Cell counting assays were performed to evaluate the cell proliferation of BMSCs. BMSCs (5 × 10⁵ cells/well in 6-well plates) were induced in four conditions for 21 days to chondrogenic differentiation evaluation, including commercial chondrogenic medium (control), 5% PRP (HG-DMEM+5% PRP), 10% PRP (HG-DMEM+10% PRP), and 15% PRP (HG-DMEM+15% PRP). The gene expression levels of ACAN, COL2A1, and SOX9 in pellets were detected. Morphological and pathological assessments were performed by the blind observer. After purifying, the percentages of cells with CD105(+)/CD34(-) and CD44(+)/CD45(-) were 96.5% and 92.9%, respectively. The proliferation of BMSCs was enhanced in all groups, and 10% PRP revealed more significant outcome than the others from day 5. The levels of ACAN, COL2A1, and SOX9 were lower in the three PRP groups than control group, but the levels of ACAN and SOX9 were higher in 10% PRP group than 5% and 15% PRP groups. Histological examinations showed that 10% PRP-treated pellets had more regular appearance, larger size, and abundant extracellular matrix than 5% or 10% PRP groups, but still inferior to commercial chondrogenic medium. In conclusion, our results show that PRP may enhance the proliferation of rabbit BMSCs. However, PRP have limited effect on chondrogenic differentiation in comparison with commercial chondrogenic medium in pellets culture.

Time-Dependent Effect of Platelet-Rich Plasma in Reducing Donor-Site Pain After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Anterior cruciate ligament reconstruction (ACLR) has a high incidence among sports players, and one important side effect of the surgery is graft donor site morbidity. Although some evidence suggests that application of platelet-rich plasma (PRP) during ACLR reduces pain and improves knee function, it is not a universal finding.

PURPOSE

To perform a meta-analysis of previous studies testing the effects of PRP on donor site morbidity after ACLR.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We reviewed PubMed (Medline), Web of Science, Embase, Scopus, and Cochrane databases to find studies testing the effects of PRP on the donor site of ACLR autograft. After identifying 4 studies, we conducted 2 meta-analyses, 1 for the effects of PRP on pain, assessed by visual analog scale (VAS), and the other for the functional knee scores. We also tested the ability of time after ACLR to predict the PRP-related reduction of pain.

RESULTS

In the 4 studies identified, 157 patients were analyzed. Although the VAS score was lower with PRP at 6 months (raw mean difference [RMD], -0.97 [95% CI, -1.59 to -0.36]; P = .001) and 12 months (RMD, -0.61 [95% CI,-1.02 to -0.21]; P = .003), the effects of PRP disappeared at 24 months (RMD, -0.08 [95% CI,-0.38 to 0.22]; P = .586). A univariate regression analysis reinforced the ability of time after ACLR to predict the PRP-related reduction of VAS pain score (r² = 0.98). However, knee function after ACLR was not improved by the use of PRP (standardized mean difference, 0.71 [95% CI,-0.17 to 1.60]; P = .114).

CONCLUSION

PRP applied to a bone-patellar tendon-bone donor site could reduce knee pain within a year, and this reduction had a correlation with time, meaning that the effect of PRP decreased with time after surgery. However, pain reduction did not reach clinical relevance and did not lead to better functional knee scores.

Bone Grafting the Patellar Defect After Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction Decreases Anterior Knee Morbidity: A Systematic Review

PURPOSE

The aim of this systematic review was to evaluate the impact of bone grafting of patellar defects on reported anterior knee morbidity and subjective outcomes after bone-patellar tendon-bone autograft reconstruction of the anterior cruciate ligament.

METHODS

A systematic electronic search of MEDLINE, Embase, Web of Science, and the Cochrane Library was carried out. All English-language prospective randomized clinical trials published from January 1, 2000, to July 24, 2020, were eligible for inclusion. All studies addressing patellar defect grafting were eligible for inclusion regardless of the timing of surgery, graft type, surgical technique, or rehabilitation protocol.

RESULTS

A total of 39 studies with 1,955 patients were included for analysis. There were 796 patients in the no patellar grafting (NPG) group, with a mean age range of 22.7 to 33.0 years, and 1,159 patients in the patellar grafting (PG) group, with a mean age range of 17.8 to 34.7 years. The visual analog scale pain score ranged from 1.2 to 5.1 in the NPG group compared with 0.3 to 3.7 in the PG group. The proportion of patients with anterior knee pain ranged from 19% to 81% in the NPG group and from 15% to 32% in the PG group. Moderate to severe kneeling pain was reported in 22% to 57% of patients in the NPG group and 10% of those in the PG group. The percentage of patients with at least 3° of extension loss ranged from 4% to 43% in the NPG group and from 2% to 11% in the PG group.

CONCLUSIONS

PG favors decreased anterior knee pain, kneeling pain, and extension loss compared with non-grafted defects; however, the functional outcomes are comparable. Owing to the heterogeneity in reporting, statistical conclusions could not be drawn.

LEVEL OF EVIDENCE

Level II, systematic review of Level I and II studies.

The efficacy of platelet rich plasma on anterior cruciate ligament reconstruction: a systematic review and meta-analysis

Anterior cruciate ligament (ACL) rupture is a common musculoskeletal injury, most frequently affecting young and physically active patients. Platelet-rich plasma (PRP) has been widely used in ACL reconstruction to augment the graft healing. However, high-level studies addressing its clinical efficacy could not reach a consensus. In this study, we assess the efficacy of PRP on pain relief, functional improvement along with radiological changes in patients who underwent ACL reconstruction. We performed comprehensive literature search and included 17 RCTs containing 970 participants who underwent ACL reconstruction. The combined data showed significant difference between PRP and control with regard to VAS score (MD: -1.12, 95% CI -1.92, -0.31; P = .007), subjective IKDC score (MD: 6.08, 95% CI 4.39, 7.77; P < .00001) and Lysholm score (MD: 8.49, 95% CI 1.63, 15.36; P = .02) by postoperative 6 months, but only pain reduction was deemed clinically important. At the end of one year's follow-up, no clinically meaningful improvement in VAS (MD: -0.47, P = .04), subjective IKDC score (MD: 3.99, P = .03), Lysholm score (MD: 2.30, P = .32), objective IKDC score (RR: 1.03, P = .09) and knee joint laxity (MD: 0.17, P = .28) was seen. In terms of radiological findings, about one-third of the studies favored PRP to facilitate the graft healing, improve the harvest site morbidity and prevent tunnel widening. In summary, moderate quality of evidence suggested that PRP could provide short-term but not long-term clinically important pain reduction.

The 2020 NBA Orthobiologics Consensus Statement

This 2020 NBA Orthobiologics Consensus Statement provides a concise summary of available literature and practical clinical guidelines for team physicians and players. We recognize that orthobiologic injections are a generally safe treatment modality with a significant potential to reduce pain and expedite early return to play in specific musculoskeletal injuries. The use of orthobiologics in sports medicine to safely reduce time loss and reinjury is of considerable interest, especially as it relates to the potential effect on a professional athlete. While these novel substances have potential to enhance healing and regeneration of injured tissues, there is a lack of robust data to support their regular use at this time. There are no absolutes when considering the implementation of orthobiologics, and unbiased clinical judgment with an emphasis on player safety should always prevail. Current best evidence supports the following: Key Points There is support for the use of leukocyte-poor platelet-rich plasma in the treatment of knee osteoarthritis. There is support for consideration of using leukocyte-rich platelet-rich plasma for patellar tendinopathy. The efficacy of using mesenchymal stromal cell injections in the management of joint and soft tissue injuries remains unproven at this time. There are very few data to suggest that current cell therapy treatments lead to any true functional tissue regeneration. Meticulous and sterile preparation guidelines must be followed to minimize the risk for infection and adverse events if these treatments are pursued.Given the high variability in orthobiologic formulations, team physicians must stay up-to-date with the most recent peer-reviewed literature and orthobiologic preparation protocols for specific injuries.Evidence-based treatment algorithms are necessary to identify the optimal orthobiologic formulations for specific tissues and injuries in athletes.Changes in the regulatory environment and improved standardization are required given the exponential increase in utilization as novel techniques and substances are introduced into clinical practice.

Platelet-Rich Plasma Applications for Achilles Tendon Repair: A Bridge between Biology and Surgery

Achilles tendon ruptures are very common tendon ruptures and their incidence is increasing in modern society, resulting in work incapacity and months off sport, which generate a need for accelerated and successful therapeutic repair strategy. Platelet-rich plasma (PRP) is emerging as adjuvant human blood-derived constructs to assist Achilles tendon rupture treatment. However, myriad PRP preparation methods in conjunction with poor standardization in the modalities of their applications impinge on the consistent effectiveness of clinical and structural outcomes regarding their therapeutic efficacy. The purpose of this review is to provide some light on the application of PRP for Achilles tendon ruptures. PRP has many characteristics that make it an attractive treatment. Elements such as the inclusion of leukocytes and erythrocytes within PRP, the absence of activation and activation ex vivo or in vivo, the modality of application, and the adjustment of PRP pH can influence the biology of the applied product and result in misleading therapeutic conclusions. The weakest points in demonstrating their consistent effectiveness are primarily the result of myriad PRP preparation methods and the poor standardization of modalities for their application. Selecting the right biological scaffold and applying it correctly to restitutio ad integrum of ruptured Achilles tendons remains a daunting and complex task.

Biologics for Tendon Surgery

This article reviews the basic anatomy and physiology of tendon healing and ways to use biologics with tendon surgery. Many different products have been used, and this article reviews the literature to distinguish what is still recommended or proven effective through research.

The Clinical Use of Platelet-Rich Plasma in Knee Disorders and Surgery-A Systematic Review and Meta-Analysis

In recent years, the interest in biological treatment of knee lesions has increased, especially the application of platelet-rich plasma is of particular note. The number of articles evaluating platelet-rich plasma (PRP) efficacy in the recovery of knee disorders and during knee surgery has exponentially increased over the last decade. A systematic review with meta-analyses was performed by assessing selected studies of local PRP injections to the knee joint. The study was completed in accordance with 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A multistep search of PubMed, Embase, Cochrane Database of Systematic Reviews, and Clinicaltrials.gov was performed to identify studies on knee surgery and knee lesion treatment with PRP. Of the 4004 articles initially identified, 357 articles focusing on knee lesions were selected and, consequently, only 83 clinical trials were analyzed using the revised Cochrane risk-of-bias tool to evaluate risk. In total, seven areas of meta-analysis reported a positive effect of PRP. Among them, 10 sub-analyses demonstrated significant differences in favor of PRP when compared to the control groups (p < 0.05). This study showed the positive effects of PRP, both on the recovery of knee disorders and during knee surgery; however further prospective and randomized studies with a higher number of subjects and with lower biases are needed.

Anterior Cruciate Ligament Reconstruction with Platelet-Rich Plasma: A Systematic Review of Randomized Control Trials

PURPOSE

To perform a systematic review of the randomized controlled trials (RCTs) evaluating the efficacy of platelet-rich plasma (PRP) to augment anterior cruciate ligament (ACL) reconstruction.

METHODS

Two independent reviewers screened the MEDLINE, The Cochrane Library, and EMBASE databases using Preferred Reporting for Systematic Reviews and Meta-Analyses guidelines for applicable RCTs evaluating the efficacy of PRP in ACL reconstruction. A meta-analysis was performed on the papers involving bone-patellar tendon-bone (BPTB) grafting.

RESULTS

Thirteen RCTs fulfilled the inclusion criteria involving 765 patients. There was no clinical improvement (Tegner, Lysholm, Knee Injury and Osteoarthritis Outcome Score, or International Knee Documentation Committee scores) in any of the 7 studies evaluating PRP alongside the hamstring tendon autograft ACL reconstructions versus the control. Two studies evaluating PRP for hamstring tendon autograft demonstrated significantly improved magnetic resonance imaging findings. Two studies analyzed the use of PRP with allograft ACL reconstruction showed no clinical, biochemical, or radiologic improvements in postoperative follow-up. No functional improvements were found when PRP was used alongside BPTB in 4 studies. There was no significant difference in visual analog scale score in the BPTB group (1.1 vs 1.5, P = .18), or tibial filling defects (P = .30).

CONCLUSIONS

This study found that the current level I evidence does not support the use of PRP to improve graft healing, improve donor-site morbidity, reduce postoperative pain levels, or improve functional outcomes following ACL reconstruction.

LEVEL OF EVIDENCE

Level I; systematic review of level I evidence.

Platelet-rich Blood Derivatives for Tendon Regeneration

Tendon injuries constitute a significant healthcare problem with variable clinical outcomes. The complex interplay of tissue homeostasis, degeneration, repair, and regeneration makes the development of successful delivery therapeutic strategies challenging. Platelet-rich hemoderivatives, a source of supra-physiologic concentrations of human therapeutic factors, are a promising application to treat tendon injuries from the perspective of tendon tissue engineering, although the outcomes remain controversial.

A Practical Guide for the Current Use of Biologic Therapies in Sports Medicine

Over the past decade, there has been an increased interest in the use of biologic therapies in sports medicine. Although these technologies are in relatively early stages of development, there have been substantial increases in marketing, patient demand, and clinical utilization of biologics, including platelet-rich plasma, bone marrow aspirate concentrate, and other cell-derived therapies. Direct-to-consumer marketing of biologics has also proliferated but is largely unregulated, and clinicians must accurately convey the safety and efficacy profiles of these therapies to patients. Because most insurance companies consider biologic treatments to be experimental or investigational for orthopaedic applications given the lack of high-quality evidence to support their efficacy, patients receiving these treatments often make substantial out-of-pocket payments. With a range of treatment costs among centers offering biologics, there is a need for appropriate and sustainable pricing and reimbursement models. Clinicians utilizing biologics must also have a thorough understanding of the recently clarified Food and Drug Administration guidelines that regulate the clinical use of cell and tissue products. There is a lack of consensus on the optimal preparation, source, delivery method, and dosing of biologic therapies, which has been exacerbated by a lack of sufficient experimental detail in most published studies. Future research must better identify the biologic target of treatment, adhere to better standards of reporting, and better integrate researchers, industry, and regulatory bodies to optimize applications.

Intra-articular and extra-articular platelet-rich plasma injections for knee osteoarthritis: A 26-week, single-arm, pilot feasibility study

AIM

Platelet Rich Plasma (PRP) is an emerging therapy for knee osteoarthritis (KOA). Studies have evaluated the effectiveness of intra-articular PRP, which ignores extra-articular tissue dysfunction and may provide incomplete treatment of KOA. The study aimed to pilot test a leukocyte-rich (mononuclear cells) PRP injection protocol for primary KOA, which consisted of single intra-articular injection and extra-articular injections on the medial coronary and medial collateral ligaments.

METHODS

A prospective 26-week single-arm uncontrolled feasibility pilot study. Patients (N = 12) with primary KOA as defined by the American Rheumatology Association, with moderate to severe medial knee pain which failed conservative management, were recruited in a university primary care clinic and received a single session of PRP injection in week 1. The primary outcome was the feasibility of the protocol at 26 weeks as defined by rates of recruitment, compliance, retention, dropout, side effects or adverse events; and treatment satisfaction. Secondary outcomes included the Western Ontario McMaster University Osteoarthritis Index, the Intermittent and Constant Osteoarthritis Pain total and subscales, objective physical function tests and EuroQol-5D.

RESULTS

Twelve of 40 potential patients were recruited in 3 months period (recruitment rate 30%, x2 = 3.33, P = 0.068). All participants adhered to the protocol and completed the follow up assessment with no dropouts (dropout rate 0%, X2= 2.67, P = 0.103). Satisfaction was high; no related adverse events were reported. Most secondary outcomes showed statistically significant improvement.

CONCLUSIONS

Concomitant intra-articular and extra-articular PRP injections were feasible and produced preliminary favourable outcomes.

Impact of Platelet-Rich Plasma Use on Pain in Orthopaedic Surgery: A Systematic Review and Meta-analysis

CONTEXT

Amid extensive debate, evidence surrounding the use of platelet-rich plasma (PRP) for musculoskeletal injuries has rapidly proliferated, and an overall assessment of efficacy of PRP across orthopaedic indications is required.

OBJECTIVES

(1) Does PRP improve patient-reported pain in musculoskeletal conditions? and (2) Do PRP characteristics influence its treatment effect?

DATA SOURCES

MEDLINE, EMBASE, Cochrane, CINAHL, SPORTDiscus, and Web of Science libraries were searched through February 8, 2017. Additional studies were identified from reviews, trial registries, and recent conferences.

STUDY SELECTION

All English-language randomized trials comparing platelet-rich therapy with a control in patients 18 years or older with musculoskeletal bone, cartilage, or soft tissue injuries treated either conservatively or surgically were included. Substudies of previously reported trials or abstracts and conference proceedings that lacked sufficient information to generate estimates of effect for the primary outcome were excluded.

STUDY DESIGN

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level 1.

DATA EXTRACTION

All data were reviewed and extracted independently by 3 reviewers. Agreement was high between reviewers with regard to included studies.

RESULTS

A total of 78 randomized controlled trials (5308 patients) were included. A standardized mean difference (SMD) of 0.5 was established as the minimum for a clinically significant reduction in pain. A reduction in pain was associated with PRP at 3 months (SMD, -0.34; 95% CI, -0.48 to -0.20) and sustained until 1 year (SMD, -0.60; 95% CI, -0.81 to -0.39). Low- to moderate-quality evidence supports a reduction in pain for lateral epicondylitis (SMD, -0.69; 95% CI, -1.15 to -0.23) and knee osteoarthritis (SMD, -0.91; 95% CI, -1.41 to -0.41) at 1 year. PRP characteristics did not influence results.

CONCLUSION

PRP leads to a reduction in pain; however, evidence for clinically significant efficacy is limited. Available evidence supports the use of PRP in the management of lateral epicondylitis as well as knee osteoarthritis.

Can platelet-rich plasma therapy save patients with ulnar collateral ligament tears from surgery?

Introduction

Platelet-rich plasma (PRP) has been shown to be effective in treating partial tears of the ulnar collateral ligament (UCL) of the elbow in overhead throwing athletes, but it is still unknown whether it has a role in complete tears. The aim of this study was to assess the effectiveness of PRP in treating complete as well as partial UCL tears. We hypothesized that trephination of the injured UCL followed by injection with PRP can promote healing of both partial and complete tears.

Methods

Thirty-four baseball players with partial or complete UCL tears confirmed by magnetic resonance imaging (MRI) were included in the study. They were all recalcitrant to more than two months of rest and physical therapy. Under ultrasound guidance, trephination of the UCL was performed using an 18-gauge needle, followed by PRP injection. Visual analog scale (VAS) scores, Disabilities of the Arm, Shoulder, and Hand (DASH) sports module scores, and sonographic ulnohumeral joint space measurements with valgus stress were all obtained prior to the procedure and six months after.

Results

Twenty-six of 30 athletes were able to return to sport with pre-injury level of play within six months after the procedure, at an average time of 12.4 weeks (range: 10-18). Four subjects needed surgical treatment for persistent UCL insufficiency. The average follow-up was 54.2 weeks (range: 26-148). The average VAS and DASH scores improved from 53.5 to 17.2 (p < 0.0001) and from 81.7 to 24.2 (p < 0.0001), respectively. The average ulnohumeral joint space opening with valgus stress decreased from 3.81 mm to 3.45 mm (p = 0.018). Subgroup analysis by injury location revealed that the average VAS score improved from 48.2 to 8.6 (p < 0.0001) and from 64.0 to 34.5 (p = 0.0023) in proximal and distal tears, respectively. The average DASH score improved from 83.8 to 17.8 (p = 0.0001) and from 77.5 to 36.7 (p < 0.0001) in proximal and distal tears, respectively. The average ulnohumeral joint space opening with valgus stress decreased from 3.64 to 3.21 mm (p = 0.003) and from 4.14 to 3.92 mm (p = 0.0023) in proximal and distal tears, respectively. There was one case with a proximal tear that needed surgical management for failure of treatment, while there were three cases needing surgery in those with distal tears.

Conclusion

Ultrasound-guided PRP injection following trephination can be an effective treatment option for both partial and complete UCL tears of the elbow, especially proximal tears. The use of this technique for complete UCL tears may allow more athletes to avoid surgery and enable them to return to play faster.

ACL Reconstruction with Augmentation: a Scoping Review

PURPOSE OF REVIEW

We reviewed the recent literature to identify and summarize new research surrounding anterior cruciate ligament reconstruction (ACLR) with augmentation in the form of additional soft tissue procedures or biologic augmentation. Specifically, we wanted to review the failure rates of these procedures in both the primary and revision settings.

METHODS

The databases Embase, PubMed, and Medline were searched on August 13, 2018, for English-language studies that reported on the use of anterior cruciate ligament reconstruction (primary and revision) in conjunction with either soft tissue or biologic augmentation. The studies were systematically screened and data abstracted in duplicates.

RECENT FINDINGS

Advancements in ACLR surgery, including soft tissue augmentation, may decrease primary and revision surgery failure rates for high-risk patients. The use of biological augmentation has shown histologic and radiographic improvements. These differences, however, have failed to be statistically significant and have not resulted in clinically significant improvements in outcome. The limited body of evidence has shown that the addition of soft tissue procedures may in fact lower the risk of graft re-rupture rates particularly in revision or in patients wishing to return to high-risk sports and activities. The use of biologic augmentation although promising in laboratory studies has yet to show any significant clinical results and therefore will require further studies to prove any efficacy.

Shear wave elastography of the healing human patellar tendon following ACL reconstruction

PURPOSE

Anterior cruciate ligament (ACL) ruptures are common and are frequently reconstructed using a patellar tendon (PT) autograft. Unfortunately, the time course of PT healing after ACL reconstruction is not particularly well understood. Thus, the primary objective of this study was to use shear wave elastography (SWE) to evaluate the extent to which shear wave speed (SWS) is associated with time after ACL reconstruction.

METHODS

Longitudinal SWE images were acquired from lateral, central, and medial regions of the PT from two groups: 30 patients who had undergone ACL reconstruction with a PT autograft within the preceding 40 months, and 30 age-matched asymptomatic control subjects. SWE images were acquired at 20° and 90° of passive flexion from both knees. In each subject group, statistical analyses assessed changes in mean SWS with time post-surgery, as well as differences in mean SWS between PT regions and limbs.

RESULTS

In the ACL reconstruction patients, mean SWS increased with time post-surgery in the lateral region of the involved knee (p = 0.025) and decreased with time post-surgery in the central region of the contralateral knee (p = 0.022).

CONCLUSION

The findings suggest that there is an association between the mechanical properties of the PT and time post-surgery in both the involved and contralateral limbs after ACL reconstruction. These changes are likely due to maturation of the donor site tissue and changes in gait/loading patterns following ACL rupture and reconstruction.

LEVEL OF EVIDENCE

Level II - Prospective Cohort.

Platelet-Rich Plasma

Platelet-rich plasma (PRP) is a promising treatment for musculoskeletal maladies and clinical data to date have shown that PRP is safe. However, evidence of its efficacy has been mixed and highly variable depending on the specific indication. Additional future high-quality large clinical trials will be critical in shaping our perspective of this treatment option. The heterogeneity of PRP preparations, both presently and historically, leads sweeping recommendations about its utility impossible to make. This heterogeneity has also made interpreting existing literature more complicated.

Ethics, Evidence Based Sports Medicine, and the Use of Platelet Rich Plasma in the English Premier League

The use of platelet rich plasma (PRP) as a novel treatment is discussed in the context of a qualitative research study comprising 38 interviews with sports medicine practitioners and other stakeholders working within the English Premier League during the 2013-16 seasons. Analysis of the data produced several overarching themes: conservatism versus experimentalism in medical attitudes; therapy perspectives divergence; conflicting versions of appropriate evidence; subcultures; community beliefs/practices; and negotiation of medical decision-making. The contested evidence base for the efficacy of PRP is presented in the context of a broader professional shift towards evidence based medicine within sports medicine. Many of the participants while accepting this shift are still committed to casuistic practices where clinical judgment is flexible and does not recognize a context-free hierarchy of evidentiary standards to ethically justifiable practice. We also discuss a tendency in the data collected to consider the use of deceptive, placebo-like, practices among the clinician participants that challenge dominant understandings of informed consent in medical ethics. We conclude that the complex relation between evidence and ethics requires greater critical scrutiny for this emerging specialism within the medical community.

Clinical and Structural Evaluations of Rotator Cuff Repair With and Without Added Platelet-Rich Plasma at 5-Year Follow-up: A Prospective Randomized Study

BACKGROUND

Platelet-rich plasma (PRP) has been studied with the objective of reducing the retear rate and improving functional outcomes after rotator cuff repair. Only one study to date has reported its midterm effect.

HYPOTHESIS

PRP promotes better functional and structural results in arthroscopic rotator cuff repair.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

All patients underwent arthroscopic single-row repair of small to medium supraspinatus tears. At the end of the surgical procedure, liquid PRP prepared by apheresis with autologous thrombin was applied in the tendon-to-bone interface in the PRP group. The outcomes were assessed by the University of California, Los Angeles (UCLA) and Constant scales and the visual analog scale (VAS) for pain at 6, 12, 24, and 60 months after surgery and magnetic resonance imaging at 12 and 60 months.

RESULTS

Of 54 patients initially randomized, we analyzed the clinical outcomes in 51 (25 control, 26 PRP) and the structural outcomes in 44 (22 each group). At 60-month follow-up, the mean UCLA scores were 32.5 ± 3.8 and 32.1 ± 4.6 in the control and PRP groups, respectively ( P = .992). The mean Constant scores were 82.0 ± 9.5 in the control group and 82.1 ± 11.0 in the PRP group ( P = .699). The mean VAS scores were 1.4 ± 1.8 and 1.5 ± 2.1 in the control and PRP groups, respectively ( P = .910). None of the clinical assessments at 6, 12, and 24 months in either group produced statistically significant differences, and both groups showed significant improvements throughout the follow-up time in the 3 evaluations ( P < .001). The control group exhibited 1 full-thickness retear (Sugaya type IV) and 11 partial-thickness retears (Sugaya type III), while the PRP group had 7 partial-thickness retears (Sugaya type III). The overall number of retears did not differ between groups ( P = .203).

CONCLUSION

PRP obtained by apheresis and applied in liquid form with the addition of thrombin at the end of single-row repair of supraspinatus tears did not promote better clinical or structural results at 60-month follow-up.

REGISTRATION

NCT01029574 ( ClinicalTrials.gov identifier).

Calcific tendinopathy of the shoulder: clinical perspectives into the mechanisms, pathogenesis, and treatment

Calcific tendinopathy (CT) of the shoulder is a common, painful condition characterized by the presence of calcium deposits in the rotator cuff tendons. Current theories indicate that CT may be the result of a cell-mediated process in which, after a stage of calcium deposition, calcifications are spontaneously resorbed. However, in a minority of cases, this self-healing process is somehow disrupted, resulting in symptoms. Recent literature shows an emerging role of biological and genetic factors underlying CT. This new evidence could supplement the classic mechanical theory of rotator cuff tendinopathy complicated by calcium precipitation, and it may also explain why the majority of the therapies currently in use are only able to provide partially satisfactory outcomes. This review aims to summarize the current knowledge about the pathological processes underlying CT of the shoulder and thereby justify the quest for advanced biological treatments of this condition when it becomes symptomatic.

Regenerative Sports Medicine: Past, Present, and Future (Adapted From the PASSOR Legacy Award Presentation; AAPMR; October 2016)

Regenerative medicine has shown dramatic expanse and evolution in the past decade. Within that milieu, physiatrists are taking an active role in research, clinical care delivery, and education. The purpose of this review is to provide a balance among evidence, theory, experience, clinical trends, and the foreseeable future. We focus on the literature that reports the research with the best methodology in each practice area, recognizing that the level of evidence varies substantially among different treatment modalities and conditions. The following elements are included: an overview of the evolution of currently available regenerative techniques, evidence base for each available modality (prolotherapy, platelet rich plasma, bone marrow aspirate concentrate and stem cells, adipose-derived stem cells, and amniotic tissue products), general principles in the application of these treatments, and discussion and a vision of what lies ahead. We expect that practitioners will use this review to facilitate clinical decision making and to provide a core knowledge base to assist when counseling patients. LEVEL OF EVIDENCE: IV.

Effect of Intraoperative Platelet-Rich Plasma Treatment on Postoperative Donor Site Knee Pain in Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction: A Double-Blind Randomized Controlled Trial

BACKGROUND

Donor site morbidity in the form of anterior knee pain is a frequent complication after bone-patellar tendon-bone (BPTB) autograft anterior cruciate ligament (ACL) reconstruction. Hypothesis/Purpose: The purpose was to examine the effect of the intraoperative administration of platelet-rich plasma (PRP) on postoperative kneeling pain. It was hypothesized that PRP treatment would reduce knee pain.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Fifty patients (mean ± SD age, 30 ± 12 years) undergoing BPTB ACL autograft reconstruction were randomized to the PRP (n = 27) or sham (n = 23) treatment. In either case, 10 mL of venous blood was drawn before the induction of anesthesia and either discarded (sham) or processed (PRP) for preparation of a PRP gel to be later mixed with donor site bone chips and inserted into the patellar defect. At 12 weeks, 6 months, 1 year, and 2 years after surgery, patients completed International Knee Documentation Committee (IKDC) forms and visual analog scale pain scores for activities of daily living and kneeling. Healing indices at the donor site were assessed by routine noncontrast magnetic resonance imaging (MRI) at 6 months. Mixed-model analysis of variance was used to assess the effect of PRP on patient symptoms and MRI indices of donor site healing, as measured by the width of the donor site defect.

RESULTS

Kneeling pain, pain with activities of daily living, and IKDC scores were not different between treatment groups at any of the time intervals ( P = .08-.83). Kneeling pain improved from 12 weeks to 6 months and from 1 to 2 years ( P < .05). IKDC scores improved substantially from 12 weeks to 6 months ( P < .001) and continued to improve to 2 years (PRP, 86 ± 19; sham, 89 ± 10). MRI indices of donor site healing were not different between treatment groups ( P = .53-.90).

CONCLUSION

Whether randomized to receive PRP in their patellar defect or not, patients continued to have similar levels of kneeling pain and patellar defect sizes after autograft BPTB ACL reconstruction. Registration: NCT01765712 ( ClinicalTrials.gov identifier).

Platelet-rich plasma in tendon-related disorders: results and indications

PURPOSE

Platelet-rich plasma (PRP) is currently the most exploited strategy in the clinical practice to provide a regenerative stimulus for tendon healing. The aim of the present study was to systematically review the available evidence on the treatment of the main tendon disorders where PRP is currently applied.

METHODS

A systematic review of the literature was performed on the use of PRP as a treatment for tendinopathies focusing on the following sites: Achilles tendon, patellar tendon, rotator cuff tendons, and lateral elbow tendons. The following inclusion criteria for relevant articles were used: clinical trials written in English language up to 21 June 2016 on the use of PRP in the conservative or surgical treatment of the aforementioned tendinopathies.

RESULTS

The research identified the following clinical trials dealing with the application of PRP in the selected tendons: 19 papers on patellar tendon (6 being RCTs: 4 dealing with PRP conservative application and 2 surgical), 24 papers on Achilles tendon (4 RCTs: 3 conservative and 1 surgical), 29 on lateral elbow tendons (17 RCTs, all conservative), and 32 on rotator cuff (22 RCTs: 18 surgical and 3 conservative).

CONCLUSION

Patellar tendons seem to benefit from PRP injections, whereas in the Achilles tendon, PRP application is not indicated neither as a conservative approach nor as a surgical augmentation. Lateral elbow tendinopathy showed an improvement in most of the high-level studies, but the lack of proven superiority with respect to the more simple whole-blood injections still questions its use in the clinical practice. With regard to rotator cuff pathology, the vast majority of surgical RCTs documented a lack of beneficial effects, whereas there is still inconclusive evidence concerning its conservative application in rotator cuff disorders.

LEVEL OF EVIDENCE

Systematic review of level I-IV trials, Level IV.

The Efficacy of Platelet-Rich Plasma on Tendon and Ligament Healing: A Systematic Review and Meta-analysis With Bias Assessment

BACKGROUND

There has been a surge in high-level studies investigating platelet-rich plasma (PRP) for tendon and ligament injuries. A number of meta-analyses have been published, but few studies have focused exclusively on tendon and ligament injuries.

PURPOSE

To perform a meta-analysis assessing the ability of PRP to reduce pain in patients with tendon and ligament injuries.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A comprehensive search of the literature was carried out in April 2017 using electronic databases PubMed, MEDLINE, and the Cochrane Library. Only level 1 studies were included. Platelet and leukocyte count, injection volume, kit used, participant age/sex, comparator, and activating agent used were recorded. The short-term and long-term efficacy of PRP was assessed using the visual analog scale (VAS) to measure pain intensity. Injury subgroups (rotator cuff, tendinopathy, anterior cruciate ligament, and lateral epicondylitis) were evaluated. Funnel plots and the Egger test were used to screen for publication bias, and sensitivity analysis was performed to evaluate the effect of potential outliers by removing studies one at a time.

RESULTS

Thirty-seven articles were included in this review, 21 (1031 participants) of which could be included in the quantitative analysis. The majority of studies published investigated rotator cuff injuries (38.1%) or lateral epicondylitis (38.1%). Seventeen studies (844 participants) reported short-term VAS data, and 14 studies (771 participants) reported long-term VAS data. Overall, long-term follow-up results showed significantly less pain in the PRP group compared with the control group (weighted mean difference [WMD], -0.84; 95% CI, -1.23 to -0.44; P < .01). Patients treated with PRP for rotator cuff injuries (WMD, -0.53; 95% CI, -0.98 to -0.09; P = .02) and lateral epicondylitis (WMD, -1.39; 95% CI, -2.49 to -0.29; P = .01) reported significantly less pain in the long term. Substantial heterogeneity was reported at baseline ( I² = 72.0%; P < .01), short-term follow-up ( I² = 72.5%; P < .01), long-term follow-up ( I² = 76.1%; P < .01), and overall ( I² = 75.8%; P < .01). The funnel plot appeared to be asymmetric, with some missingness at the lower right portion of the plot suggesting possible publication bias.

CONCLUSION

This review shows that PRP may reduce pain associated with lateral epicondylitis and rotator cuff injuries.

Does Platelet-Rich Plasma Lead to Earlier Return to Sport When Compared With Conservative Treatment in Acute Muscle Injuries? A Systematic Review and Meta-analysis

PURPOSE

To compare the time to return to sport and reinjury rate after platelet-rich plasma (PRP) injection versus control therapy (i.e., physiotherapy or placebo injection) in patients with acute grade I or II muscle strains.

METHODS

All eligible studies comparing PRP against a control in the treatment of acute (≤7 days) grade I or II muscle strains were identified. The primary outcome was time to return to play. The secondary outcome was the rate of reinjury at a minimum of 6 months of follow-up. Subgroup analysis was performed to examine the efficacy of PRP in hamstring muscle strains alone. The checklist to evaluate a report of a nonpharmacologic trial (CLEAR-NPT) was used to assess the quality of studies.

RESULTS

Five randomized controlled trials including a total of 268 patients with grade I and II acute muscle injuries were eligible for review. The pooled results revealed a significantly earlier return to sport for the PRP group when compared with the control group (mean difference, -5.57 days [95% confidence interval, -9.57 to -1.58]; P = .006). Subgroup analysis showed no difference in time to return to sport when comparing PRP and control therapy in grade I and II hamstring muscle strains alone (P = .19). No significant difference was noted in the rate of reinjury between the 2 groups (P = .50) at a minimum of 6 months of follow-up.

CONCLUSIONS

Evidence from the current literature, although limited, suggests that the use of PRP may result in an earlier return to sport among patients with acute grade I or II muscle strains without significantly increasing the risk of reinjury at 6 months of follow-up. However, no difference in time to return to sport was revealed when specifically evaluating those with a grade I or II hamstring muscle strain.

LEVEL OF EVIDENCE

Level II, meta-analysis of level I and II studies.

A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature

BACKGROUND

Platelet-rich plasma (PRP) is a blood-derived preparation whose use has grown exponentially in orthopaedic practice. However, there remains an unclear understanding of the biological properties and effects of PRP on musculoskeletal healing. Heterogeneous processing methods, unstandardized nomenclature, and ambiguous classifications make comparison among studies challenging. A comprehensive assessment of orthopaedic clinical PRP trials is key to unraveling the biological complexity of PRP, while improving standardized communication. Toward this goal, we performed a systematic review of the PRP preparation protocols and PRP composition utilized in clinical trials for the treatment of musculoskeletal diseases.

METHODS

A systematic review of the literature was performed from 2006 to 2016. Inclusion criteria were human clinical trials, English-language literature, and manuscripts that reported on the use of PRP in musculoskeletal/orthopaedic conditions. Basic-science articles, editorials, surveys, special topics, letters to the editor, personal correspondence, and nonorthopaedic applications (including cosmetic use or dental application studies) were excluded.

RESULTS

A total of 105 studies (in 104 articles) met the inclusion criteria for analysis. Of these studies, only 11 (10%) provided comprehensive reporting that included a clear description of the preparation protocol that could be used by subsequent investigators to repeat the method. Only 17 studies (16%) provided quantitative metrics on the composition of the final PRP product.

CONCLUSIONS

Reporting of PRP preparation protocols in clinical studies is highly inconsistent, and the majority of studies did not provide sufficient information to allow the protocol to be reproduced. Furthermore, the current reporting of PRP preparation and composition does not enable comparison of the PRP products being delivered to patients. A detailed, precise, and stepwise description of the PRP preparation protocol is required to allow comparison among studies and provide reproducibility.

Platelet-Rich Plasma Injections as a Treatment for Refractory Patellar Tendinosis: A Meta-Analysis of Randomised Trials

Purpose

Patellar tendinosis (PT) is a common condition amongst athletes. In this study, we perform a meta-analysis on randomised controlled trials (RCTs) to evaluate the use of platelet-rich plasma (PRP) for refractory PT.

Methods

A literature search was undertaken in various databases from their year of inception to October 2015. The primary outcome measure was the Victorian Institute of Sports Assessment-Patella (VISA-P) score.

Results

We identified 2 RCTs comparing PRP injections to alternative treatment options (extracorporeal shockwave therapy [ESWT] and dry needling of the tendon). Meta-analysis showed no significant difference in mean VISA-P scores between PRP injection and control at early assessment (2 or 3 months; estimated difference in means, 11.9; standard error [SE], 7.4; 95% confidence interval [CI], -2.7 to 26.4; p=0.109). However, PRP was statistically better than control with regards to VISA-P scores at longer follow-up (6 months or longer; estimated difference in means, 12.7; SE, 4.4; 95% CI, 4.1 to 21.3; p=0.004).

Conclusions

There is a paucity of RCTs evaluating the role of PRP in PT. Our results suggest that, based on limited evidence, PRP is superior over other established non-surgical treatments (dry needling and ESWT) for refractory PT. Larger RCTs may allow better characterisation of the role of PRP in this condition.

ACL Primary Repair with Bone Marrow Stimulation and Growth Factors. A Review of Literature

Anterior cruciate ligament (ACL) ruptures represent a common pathology, especially in young and active patients. Spontaneous repair, although reported in some studies, is altered by local conditions, thus emerges the need to perform reconstruction of the ACL. It is reported that 3,430 primary reconstructions and around 267 revisions are performed yearly in Sweden. Some reconstructions result in biological failure, which represents the inability of the graft to incorporate and remodel in order to perform its role as a knee stabilizer. Orthobiology, a new concept that includes growths factors, stem cells, and different scaffolds, could represent a solution to a better outcome of this procedure. This manuscript is a review of different therapeutic strategies used for enabling ACL regeneration, including in vitro ACL-bio-enhanced repair that is currently being developed. Substantial progress is to be expected in the area of ACL surgery.

Platelet-rich plasma (PRP) for knee disorders

Platelet-rich plasma (PRP) is an autologous blood product with platelet concentrations above baseline values. The process involves the extraction of blood from the patient which is then centrifuged to obtain a concentrated suspension of platelets by plasmapheresis. It then undergoes a two-stage centrifugation process to separate the solid and liquid components of the anticoagulated blood. PRP owes its therapeutic use to the growth factors released by the platelets which are claimed to possess multiple regenerative properties.

In the knee, PRP has been used in patients with articular cartilage pathology, ligamentous and meniscal injuries.

There is a growing body of evidence to support its use in selected indications and this review looks at the most recent evidence. We also look at the current UK National Institute of Health & Clinical Excellence (NICE) guidelines with respect to osteoarthritis and the use of PRP in the knee.

Cite this article: EFORT Open Rev 2017;2:28–34. DOI: 10.1302/2058-5241.2.160004.

Optimisation of platelet concentrates therapy: Composition, localisation, and duration of action

Platelet concentrates (PC) generally refers to a group of products that are prepared from autologous blood intended to enhance healing activities. PC therapy is now very popular in treating musculoskeletal injuries; however, inconsistent clinical results urge the need to understand the working mechanism of PC. It is generally believed that the platelet-derived bioactive factors are the active constituents, and their bioavailability in the vicinity of the lesion sites determines the treatment efficacies. Therefore, the composition, localisation, and duration of the action of PC would be key determinants. In this review, we discuss how different preparations and delivery methods of PC would affect the treatment outcomes with respect to clinical evidence about PC therapy for osteoarthritis, tendinopathies, rotator cuff tears, anterior cruciate ligament injuries, and bone fractures. This review can be used as a quick guide for the use of PC therapy and provide insights for the further optimisation of the therapy in the near future.

Biologic Treatments for Sports Injuries II Think Tank-Current Concepts, Future Research, and Barriers to Advancement, Part 1: Biologics Overview, Ligament Injury, Tendinopathy

Biologic therapies, including stem cells, platelet-rich plasma, growth factors, and other biologically active adjuncts, have recently received increased attention in the basic science and clinical literature. At the 2015 AOSSM Biologics II Think Tank held in Colorado Springs, Colorado, a group of orthopaedic surgeons, basic scientists, veterinarians, and other investigators gathered to review the state of the science for biologics and barriers to implementation of biologics for the treatment of sports medicine injuries. This series of current concepts reviews reports the summary of the scientific presentations, roundtable discussions, and recommendations from this think tank.