Cryopreserved Amniotic Membrane Improves Clinical Outcomes Following Microdiscectomy

Revision Meniscal Repair With Amniotic Membrane Augmentation

Meniscal injury is common, and despite modern techniques, the failure rate following repair remains high. While there are recent treatment advances in the form of biologics, there is limited evidence and agreement on these emerging therapies and their role in meniscal healing. Amniotic tissue (umbilical cord allograft) is a biologic augmentation therapy that has been utilized in other musculoskeletal applications but has not been reported for use in meniscal repair. We describe a technique to deliver an allograft amniotic membrane into a meniscus tear repair site, potentially optimizing healing.

Presence of heavy chain-hyaluronan/pentraxin 3 (HC-HA/PTX3) complex in human umbilical cord

The heavy chain (HC)-hyaluronan (HA)/pentraxin 3 (HC-HA/PTX3) complex is formed by tumor necrosis factor-stimulated gene-6 (TSG-6) catalyzing the covalent (ester bond) transfer of HC1 from inter-α-trypsin inhibitor (IαI) to HA followed by tight binding of PTX3. The presence of such a complex has been found in human amniotic membrane (AM) and is considered to be a major matrix component responsible for its anti‑inflammatory and anti‑scarring properties to promote regenerative healing. Because the therapeutic potentials of AM and umbilical cord (UC) are similar, we herein evaluated whether human UC also contains HC-HA/PTX3. Immunostaining of UC cross-sections showed abundant PTX3, HC1, HA, TSG-6, and bikunin. Western blot analysis suggested the presence of HC1 complex bound via a NaOH-sensitive bond and tightly bound to PTX3 multimer in UC and AM extracts but not in chorion and placenta extracts. HC-HA/PTX3 was purified from UC extract by successive runs of density gradient ultracentrifugation and verified the presence of HC1 but not HC2 or HC3 based on western blot analysis. These results suggest the presence of HC-HA/PTX3 complex in UC is similar to AM.

Annulus Fibrosus Repair for Lumbar Disc Herniation: A Meta-Analysis of Clinical Outcomes From Controlled Studies

STUDY DESIGN

Meta-analysis.

OBJECTIVES

This study aimed to summarize the clinical efficacy and safety of the various annular defect repair methods that have emerged in recent years.

METHODS

A meta-analysis of randomized and non-randomized controlled trials was conducted. Articles from PubMed, Embase, and the Cochrane Library (CENTRAL) on Lumbar disc herniation treatment with annular repair published from inception to April 2, 2022 were included. We summarized the clinical efficacy and safety of annular repair techniques based on a random-effects model meta-analysis.

RESULTS

7 randomized controlled studies and 8 observational studies with a total of 2161 participants met the inclusion criteria. The pooled data analysis showed that adding the annular repair technique reduced postoperative recurrence rate, reoperation rate, and loss of intervertebral height compared with lumbar discectomy alone. Subgroup analysis based on different annular repair techniques showed that the Barricaid Annular Closure Device (ACD) was effective in preventing re-protrusion and reducing reoperation rates, while there was no significant difference between the other subgroups. The annulus fibrosus suture (AFS) did not improve the postoperative Oswestry Disability Index (ODI). No statistically significant difference was observed in the incidence of adverse events between the annular repair and control groups.

CONCLUSIONS

Lumbar discectomy combined with ACD can effectively reduce postoperative recurrence and reoperation rates in patients with LDH. AFS alone was less effective in reducing recurrence and reoperation rates and did not improve postoperative pain and function.

Amniotic membrane attenuates heterotopic ossification following high-dose bone morphogenetic protein-2 treatment of segmental bone defects

Treatment of large bone defects with supraphysiological doses of bone morphogenetic protein-2 (BMP-2) has been associated with complications including heterotopic ossification (HO), inflammation, and pain, presumably due to poor spatiotemporal control of BMP-2. We have previously recapitulated extensive HO in our rat femoral segmental defect model by treatment with high-dose BMP-2 (30 μg). Using this model and BMP-2 dose, our objective was to evaluate the utility of a clinically available human amniotic membrane (AM) around the defect space for guided bone regeneration and reduction of HO. We hypothesized that AM surrounding collagen sponge would attenuate heterotopic ossification compared with collagen sponge alone. In vitro, AM retained more BMP-2 than a synthetic poly(ε-caprolactone) membrane through 21 days. In vivo, as hypothesized, the collagen + AM resulted in significantly less heterotopic ossification and correspondingly, lower total bone volume (BV), compared with collagen sponge alone. Although bone formation within the defect was delayed with AM around the defect, by 12 weeks, defect BVs were equivalent. Torsional stiffness was significantly reduced with AM but was equivalent to that of intact bone. Collagen + AM resulted in the formation of dense fibrous tissue and mineralized tissue, while the collagen group contained primarily mineralized tissue surrounded by marrow-like structures. Especially in conjunction with high doses of growth factor delivered via collagen sponge, these findings suggest AM may be effective as an overlay adjacent to bone healing sites to spatially direct bone regeneration and minimize heterotopic ossification.

Placental Tissues as Biomaterials in Regenerative Medicine

Placental tissues encompass all the tissues which support fetal development, including the placenta, placental membrane, umbilical cord, and amniotic fluid. Since the 1990s there has been renewed interest in the use of these tissues as a raw material for regenerative medicine applications. Placental tissues have been extensively studied for their potential contribution to tissue repair applications. Studies have attributed their efficacy in augmenting the healing process to the extracellular matrix scaffolds rich in collagens, glycosaminoglycans, and proteoglycans, as well as the presence of cytokines within the tissues that have been shown to stimulate re-epithelialization, promote angiogenesis, and aid in the reduction of inflammation and scarring. The compositions and properties of all birth tissues give them the potential to be valuable biomaterials for the development of new regenerative therapies. Herein, the development and compositions of each of these tissues are reviewed, with focus on the structural and signaling components that are relevant to medical applications. This review also explores current configurations and recent innovations in the use of placental tissues as biomaterials in regenerative medicine.

Comparison of interventions for lumbar disc herniation: a systematic review with network meta-analysis

BACKGROUND

Implants for use in disc herniation surgery have been commercially available for some time. Several clinical trials have shown promising results. There are now a wide variety of surgical methods for treating lumbar disc herniation.

PURPOSE

The objective of this systematic review was to compare all current surgical methods for disc herniation, including newer methods with implants for annulus repair and dynamic stabilization.

STUDY DESIGN

Systematic review and network meta-analysis.

METHODS

PRISMA-P guidelines were followed in this review. Literature search in PubMed, Embase, and Cochrane library databases identified eligible randomized controlled trials (RCT) studies comparing interventions for lumbar disc surgery. The investigated outcomes were: changes in pain score, disability score and reoperation rate with a minimum follow-up of 1 year. Risk of bias was assessed in concordance with Cochrane Neck and Back Review Group recommendation. A network meta-analysis was performed using gemtc and BUGSnet software, and each outcome evaluated using Confidence in Network Meta-Analysis (CINeMA).

RESULTS

Thirty-two RCT studies, with 4,877 participants, and eight different interventions were identified. A significant difference was seen in change of pain score, as all treatments were superior to conservative treatment and percutaneous discectomy. This difference was only found to be of clinically importance when comparing conservative treatment and dynamic stabilization. There was no significant difference in reoperation rates or change in disability score, regardless of treatment. However, SUCRA plots showed a trend in ranking annulus repair and dynamic stabilization highest. Risk of bias assessment showed that 15 studies had a high overall risk of bias. Meta-regression with risk of bias as covariate did not indicate any influence in risk of bias on the model. Confidence in Network Meta-Analysis evaluation showed a high level of confidence for all treatment comparisons.

CONCLUSIONS

With this network meta-analysis, we have aimed to compare all treatments for herniated lumbar disc in one large comprehensive systematic review and network meta-analysis. We have compared across the three main outcomes: disability score, pain score and reoperation rate. We were not able to rank one single treatment as the best. Most of the treatment performed at the same level. However percutaneous discectomy and conservative treatment consistently performed worse than the other treatments. In general, the CINeMA evaluation according to the GRADE recommendations gave a high level of confidence for the study comparisons.

Amniotic Umbilical Cord Particulate for Discogenic Pain

Context

Discogenic low back pain is the most common type of low back pain and is a major cause of morbidity worldwide. Current nonoperative treatment options are limited in efficacy and lack evidence of long-term pain relief; thus, there is an unmet clinical need for an effective treatment for patients with discogenic pain. Amniotic membrane and umbilical cord (AMUC) particulate may be useful in relieving pain and inhibiting the degenerative cascade in patients with discogenic pain by reducing inflammation.

Objective

To evaluate the effectiveness of AMUC particulate for discogenic pain.

Methods

Six months of conservative therapy failed in patients who had discogenic pain confirmed by magnetic resonance imaging and provocative discography. They subsequently received intradiskal injection of 50 to 100 mg of AMUC particulate for cervical, lumbar, and lumbosacral disks.

Results

A total of 11 patients with 20 disks were included. Before treatment, all patients reported severe pain, and 10 patients took opioids daily. After treatment, the median reported pain relief was 40%, 50%, and 75% at 1-month (n=6), 3 months (n=8), and 6 months (n=5), respectively. Complete pain relief was noted in 1 patient; however, 2 patients (18%) reported no pain relief at 1 and 3 months. No adverse events, repeated procedures, or complications occurred.

Conclusion

This preliminary evidence suggests that a single intradiskal injection of AMUC particulate is safe and may provide symptomatic pain relief in some patients with discogenic pain.

Comparison of amniotic membrane transplantation and carpal tunnel syndrome release surgery (CTRS) and CTRS alone: Clinical outcomes at 1-year follow-up

Carpal tunnel syndrome (CTS) is the most common focal entrapment mononeuropathy, comprising medium nerve chronic inflammation and fibrosis. Although carpal tunnel release surgery (CTRS) has demonstrated to be effective, around 3% to 25% of CTRS show recurrence. Amniotic membrane transplantation (AMT) has been used in different pathologies inhibiting inflammation and fibrosis and promoting nerve repair. The aim of this study was to determine the efficacy of AMT in CTRS. The present study comprised a randomized, single-blind controlled trial to compare the 1-year follow-up outcomes of AMT in CTRS (AMT group) or CTRS alone (control group) in patients with CTS. Thirty-five patients with unilateral or bilateral CTS were enrolled, and 47 wrists were randomized into two groups: the AMT group and the control group. To compare the outcomes, three different questionnaires scores (Boston Carpal Tunnel Syndrome Questionnaire, Disabilities of the Arm, Shoulder, and Hand, and Historical-Objective scale) were used. Evaluations were assessed at baseline and at 15 days, 1, 3, 6, and 12 months after surgery. Compared with the control group, the AMT group showed significant (p < 0.05) reductions in all scores from 6 months after surgery until the end of the study. Both AMT and control groups showed significant intragroup differences in all scores, since the first month after surgery until the end of the study in comparison with the baseline scores. Taken together, these results indicate that CTRS in conjunction with AMT is more effective than CTRS alone in patients with CTS at 1-year follow-up. Clinical Trial: NCT04075357; Amniotic Membrane in Carpal Tunnel Syndrome.

Orthobiologic Supplementation Improves Clinical Outcomes Following Lumbar Decompression Surgery

Background

Endoscopic-assisted lumbar decompression is a minimally invasive spine surgery which has been touted to reduce collateral tissue damage, incisional pain, recovery time and complications. Residual back or leg pain and recurrent herniation are commonly reported post-operative outcomes. It has been suggested that injecting orthobiologics like cryopreserved amniotic-derived products (ADPs) and bone marrow aspiration (BMA) into the surgery site would have additional benefit on patient outcomes. This is a Western Institutional Review Board (WIRB)-approved level 1, randomized controlled trial of prospectively collected patient demographic and outcomes data for endoscopic-assisted lumbar decompression surgery. The primary goal of this study was to compare patient outcomes of orthobiologic supplementation during endoscopic-assisted lumbar decompression surgery.

Methods

Following WIRB approval, 269 patients underwent lumbar endoscopic-assisted decompressive surgery between January 2011 and October 2017. Patients were randomized to receive ADP, BMA, both, or no supplementation (control group). Outcomes were measured by post-operative questionnaires (visual analog scale (VAS), Oswestry disability index (ODI), 36-item short-form health survey (SF-36)) over 12 months.

Results

Mean VAS-leg for either BMA or ADP group displayed statistically significant improvements at 2 weeks (3.55 vs. 4.77, P = 0.002), 6 months (2.34 vs. 3.37, P = 0.026), and 9 months (2.18 vs. 3.57, P = 0.01) compared to no supplementation group (control group). Similarly, improvements in mean VAS-back were significant at 2 weeks (3.98 vs. 5.01, P = 0.011), 2 months (3.22 vs. 3.93, P = 0.04), 9 months (2.38 vs. 4.11, P = 0.004), and 12 months (2.23 vs. 3.58, P = 0.011) compared to no supplementation group (control group). There were statistically significant differences in the ODI (2 weeks, 42.19 vs. 31.11, P = 0.014) and SF-36 (4 months, 85 vs. 63, P = 0.043 for ADP only), but these differences did not subsist over time. Two patients (one control, one ADP) re-herniated at the same level.

Conclusions

Orthobiologic BMA and ADP resulted in improved pain control during early post-operative periods.

Human Amniotic Membrane for the Prevention of Intradural Spinal Cord Adhesions: Retrospective Review of its Novel Use in a Case Series of 14 Patients

BACKGROUND

Tethering after spinal surgery is caused by adhesions that arise from intradural tissue manipulation. Microsurgical detethering is the only treatment for symptomatic patients, but retethering occurs commonly and no treatment is widely available to prevent this complication.

OBJECTIVE

To apply human amniotic membrane (HAM) grafts, which are immune-privileged and known to possess antifibrogenic properties, in patients requiring microsurgical detethering. For this first-in-human use, we evaluated the safety and potential efficacy of these grafts for preventing retethering.

METHODS

We retrospectively reviewed the medical records of all patients who required detethering surgery and received an HAM graft between 2013 and 2016 at our institution after various previous intradural spinal surgeries. In all 14 cases, intradural lysis of adhesions was achieved, an HAM graft was sewn in place intradurally, and a dural patch was closed in a watertight fashion over the graft.

RESULTS

Fourteen patients had received HAM grafts to prevent retethering. All patients had at least 6 mo of follow-up (mean follow-up, 14 mo). Retethering was noted in only 1 patient. Surgical re-exploration showed that the retethering occurred caudal to the edge of the HAM graft, with no tethering underneath the original graft. No complications were attributed specifically to the HAM graft placement.

CONCLUSION

This first-in-human series provides evidence that HAM grafts are a safe and potentially efficacious method for preventing retethering after microsurgical intradural lysis of adhesions. These results lay the groundwork for further prospective controlled trials in patients with this difficult-to-treat pathology.

Cryopreserved amniotic membrane and umbilical cord particulate matrix for partial rotator cuff tears: A case series

Amniotic membrane (AM) and umbilical cord (UC) are well known to have anti-inflammatory properties and have been shown to promote healing in various orthopedic indications. This study investigated whether intra-articular injection of AM/UC particulate matrix promotes healing of partial rotator cuff tears (RCTs).A case series was performed on 10 patients that received injection of 50 mg AM/UC for partial RCTs that were refractory to conservative treatment. Outcomes included Penn Shoulder Score (PSS) questionnaire, range of motion examination, and magnetic resonance imaging (MRI) analysis before and at 6 months. Final MRI analysis was performed by a musculoskeletal radiologist in a blinded fashion.Average PSS score (out of 100) increased from 46.8 ± 23.7 at baseline to 82.0 ± 19.1 at 6 months. The average PSS sub-scores of pain, satisfaction, and function increased 78.4%, 37.1%, and 82.3% from baseline, respectively. The subject's range of motion was 77.9% at baseline and increased to 99.9% at 6-months. Follow-up MRI scans did not demonstrate any significant change in RCT size. No adverse events were noted.This small case series provides preliminary data for use of cryopreserved AM/UC particulate matrix in patients with refractory partial RCTs.

The Science and Clinical Applications of Placental Tissues in Spine Surgery

STUDY DESIGN

Narrative literature review.

OBJECTIVES

Placental tissue, amniotic/chorionic membrane, and umbilical cord have seen a recent expansion in their clinical application in various fields of surgery. It is important for practicing surgeons to know the underlying science, especially as it relates to spine surgery, to understand the rationale and clinical indication, if any, for their usage.

METHODS

A literature search was performed using PubMed and MEDLINE databases to identify studies reporting the application of placental tissues as it relates to the practicing spine surgeon. Four areas of interest were identified and a comprehensive review was performed of available literature.

RESULTS

Clinical application of placental tissue holds promise with regard to treatment of intervertebral disc pathology, preventing epidural fibrosis, spinal dysraphism closure, and spinal cord injury; however, there is an overall paucity of high-quality evidence. As such, evidence-based guidelines for its clinical application are currently unavailable.

CONCLUSIONS

There is no high-level clinical evidence to support the application of placental tissue for spinal surgery, although it does hold promise for several areas of interest for the practicing spine surgeon. High-quality research is needed to define the clinical effectiveness and indications of placental tissue as it relates to spine surgery.