Nonoperative and Operative Soft-Tissue, Cartilage, and Bony Regeneration and Orthopaedic Biologics of the Shoulder: An Orthoregeneration Network (ON) Foundation Review

Staying out of trouble: FDA regulation of orthobiologics and the shoulder surgeon

BACKGROUND

Food and Drug Administration (FDA) regulation of orthobiologics can be challenging to interpret for the nonregulatory scientist. However, understanding how regulations apply to clinical use of these orthobiologic products is critical, as there are both ethical and legal ramifications to using orthobiologics in conflict with regulations. Recent FDA guidances have attempted to clarify these issues, although questions still remain regarding nuances in regulatory applications.

METHODS

FDA guidances, industry blogs, and relevant publications were searched for citations regarding recent orthobiologics and regulations. These sources were compiled into a current assessment of FDA regulations regarding the use of orthobiologics in the shoulder.

RESULTS

Key to understanding these regulations is the FDA differentiation of human cellular and tissue-based products into 361 and 351 category products. Although some controversy still exists, the FDA has attempted to clarify these issues with several recent guidances. Of equal importance, the FDA has ended enforcement discretion for many biologic products in June of 2021, creating a previously tolerated class of orthobiologics that now requires an Investigational New Drug application and subsequent Biologic License Application to legally market these orthobiologics. The same surgical procedure exception was further clarified in 2017 to exempt facilities from regulatory controls when specific guidelines are met.

CONCLUSIONS

This article attempts to clarify the current thinking on FDA regulations and will allow the shoulder and elbow surgeon to stay within the current bounds of ethical and legal use of these products.

Bone Marrow Stimulation for Arthroscopic Rotator Cuff Repair: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Bone marrow stimulation (BMS) has been proposed to augment healing at the time of arthroscopic rotator cuff repair (ARCR) by creating several bone marrow vents in the footprint of the rotator cuff, allowing mesenchymal stem cells, platelets, and growth factors to cover the area as a "crimson duvet."

PURPOSE

To perform a meta-analysis of randomized controlled trials (RCTs) to compare the outcomes after BMS and a control for those undergoing ARCR.

STUDY DESIGN

Meta-analysis; Level of evidence, 1.

METHODS

A literature search of 3 databases was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. RCTs comparing BMS and a control for ARCR were included. Clinical outcomes were compared, and a P value <.05 was considered to be statistically significant.

RESULTS

A total of 7 RCTs with 576 patients were included. Overall, 18.8% of patients treated with BMS and 21.0% of patients treated with a control had a retear (I2 = 43%; P = .61). With BMS, the mean Constant score was 88.2, and with the control, the mean Constant score was 86.7 (P = .12). Additionally, there was no significant difference in the American Shoulder and Elbow Surgeons score (94.3 vs 93.2, respectively; P = .31) or visual analog scale score (0.9 vs 0.9, respectively; P = .89).

CONCLUSION

The level 1 evidence in the literature did not support BMS as a modality to improve retear rates or clinical outcomes after ARCR.

Mid-term outcomes of microfracture for the treatment of focal, full-thickness cartilage defects isolated to the humeral head

BACKGROUND

While microfracture has been shown to be an effective treatment for chondral lesions in the knee, evidence to support its use for chondral defects in the shoulder is limited to short-term outcomes studies. The purpose of this study is to determine if microfracture provides pain relief and improved shoulder function in patients with isolated focal chondral defects of the humeral head at a minimum 5-year follow-up.

METHODS

Patients who underwent microfracture procedure for isolated focal chondral defects of the humeral head with a minimum follow-up of 5 years between 02/2006 and 08/2016 were included. At minimum 5-year follow-up, pre- and postoperative patient-reported outcome (PRO) measures were collected, including the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), Short Form-12 (SF-12) Physical Component Summary (PCS), Visual Analog Scale (VAS) for pain, and patient satisfaction level (1 = unsatisfied, 10 = very satisfied). Demographic, injury, and surgical data were retrospectively reviewed. Surgical failure was defined as revision surgery for humeral chondral defects or conversion to arthroplasty. Kaplan-Meier analysis was performed to determine survivorship at 5 years.

RESULTS

A total of 17 patients met inclusion/exclusion criteria. There were 15 men and 2 women with an average age of 51 years (range 36-69) and an average follow-up of 9.4 years (range 5.0-15.8). The median ASES score improved from 62 (range: 22-88) preoperatively to 90 (range: 50-100) postoperatively (P = .011). Median satisfaction was 8 out of 10 (range: 2-10). There was no correlation between patient age or defect size and PROs. Postoperatively, patients reported significant improvements in recreational and sporting activity as well as the ability to sleep on the affected shoulder (P ≤ .05). Three patients failed and required revision surgery. The Kaplan-Meier analysis determined an overall survivorship rate of 80% at 5 years.

CONCLUSION

The presented study illustrates significant improvements for PROs, improved ability to perform recreational and sporting activities, and a survival rate of 80% at a mean of 9.4 years after microfracture for focal chondral humeral head defects.

Orthobiologics as an adjunct in treatment of femoroacetabular impingement syndrome: cell-based therapies facilitate improved postoperative outcomes in the setting of acetabular chondral lesions-a systematic review

PURPOSE

To evaluate studies utilizing orthobiologics in the management of femoroacetabular impingement syndrome (FAIS) to (1) assess the indications for usage, and (2) analyze patient-reported outcome measures (PROM) following treatment. It was hypothesized that orthobiologics would (1) be utilized for symptomatic FAIS in the setting of labral or chondral pathology, and (2) improve PROM at most recent follow-up.

METHODS

The Pubmed, Ovid Medline, Cochrane, and Web of Science databases were searched for clinical studies evaluating orthobiologics [hyaluronic acid (HA), platelet-rich plasma (PRP), or cell-based therapy (CBT) for treatment of FAIS. Exclusion criteria included orthobiologics used in conjunction with cartilage transfer or scaffolding procedures and a primary indication other than FAIS. Data collection included patient demographics, indications, and baseline and most recent PROM.

RESULTS

Eleven studies (one level I, four level II, four level III, and two level IV evidence) met inclusion criteria, consisting of 440 patients with mean ages ranging from 32.8 to 47 years. All 11 studies demonstrated an improvement in PROM from baseline to most-recent follow-up. Four studies administered PRP either intraoperatively or the day after surgery as an adjunct to labral repair. CBT was used intraoperatively in the setting of acetabular chondral lesions (three studies) and labral repair (one study). When comparing to a control group at most recent follow-up, three PRP cohorts demonstrated similar PROM (n.s.), while one PRP group exhibited worse visual analog pain scores (2.5 vs. 3.4, p = 0.005) and modified Harris Hip Scores (mHHS) (82.6 vs. 78.7, p = 0.049). The four CBT studies reported favorable results compared to a control group, with a significantly higher mHHS at most recent follow-up or mean improvement from baseline in Hip Outcome Score-Activities of Daily Living (p < 0.05). Three studies reported on HA, which was utilized exclusively in the nonoperative setting.

CONCLUSIONS

Intraoperative PRP and CBT have been commonly reported in the setting of hip arthroscopy for labral repairs and acetabular chondral lesions, respectively. The CBT cohorts demonstrated more favorable PROM at most recent follow-up when compared to a control group, though these results should be interpreted with caution due to heterogeneity of orthobiologic preparations.

LEVEL OF EVIDENCE

IV.

In Vitro and In Vivo Biocompatibility Assessment of a Thermosensitive Injectable Chitosan-Based Hydrogel for Musculoskeletal Tissue Engineering

Musculoskeletal impairments, especially cartilage and meniscus lesions, are some of the major contributors to disabilities. Thus, novel tissue engineering strategies are being developed to overcome these issues. In this study, the aim was to investigate the biocompatibility, in vitro and in vivo, of a thermosensitive, injectable chitosan-based hydrogel loaded with three different primary mesenchymal stromal cells. The cell types were human adipose-derived mesenchymal stromal cells (hASCs), human bone marrow stem cells (hBMSCs), and neonatal porcine infrapatellar fat-derived cells (IFPCs). For the in vitro study, the cells were encapsulated in sol-phase hydrogel, and then, analyzed via live/dead assay at 1, 4, 7, and 14 days to compare their capacity to survive in the hydrogel. To assess biocompatibility in vivo, cellularized scaffolds were subcutaneously implanted in the dorsal pouches of nude mice and analyzed at 4 and 12 weeks. Our data showed that all the different cell types survived (the live cell percentages were between 60 and 80 at all time points in vitro) and proliferated in the hydrogel (from very few at 4 weeks to up to 30% at 12 weeks in vivo); moreover, the cell-laden hydrogels did not trigger an immune response in vivo. Hence, our hydrogel formulation showed a favorable profile in terms of safety and biocompatibility, and it may be applied in tissue engineering strategies for cartilage and meniscus repair.

Harnessing Biofabrication Strategies to Re-Surface Osteochondral Defects: Repair, Enhance, and Regenerate

Osteochondral tissue (OC) is a complex and multiphasic system comprising cartilage and subchondral bone. The discrete OC architecture is layered with specific zones characterized by different compositions, morphology, collagen orientation, and chondrocyte phenotypes. To date, the treatment of osteochondral defects (OCD) remains a major clinical challenge due to the low self-regenerative capacity of damaged skeletal tissue, as well as the critical lack of functional tissue substitutes. Current clinical approaches fail to fully regenerate damaged OC recapitulating the zonal structure while granting long-term stability. Thus, the development of new biomimetic treatment strategies for the functional repair of OCDs is urgently needed. Here, we review recent developments in the preclinical investigation of novel functional approaches for the resurfacing of skeletal defects. The most recent studies on preclinical augmentation of OCDs and highlights on novel studies for the in vivo replacement of diseased cartilage are presented.

Interpositional scaffold anchor rotator cuff footprint tear repair: excellent survival, healing, and early outcomes

PURPOSE

Shoulder function limitation duration after a full-thickness rotator cuff tendon (RCT) tear may influence post-repair healing and outcomes. A suture anchor was developed to improve footprint repair fixation and healing through biological fluid delivery and scaffold augmentation. The primary multicenter study objective was to evaluate RCT repair failure rate based on 6-month MRI examination, and device survival at 1-year follow-up. The secondary objective was to compare the clinical outcomes of subjects with shorter- and longer-term shoulder function limitation duration.

METHODS

Seventy-one subjects (46 men) with moderate-to-large RCT tears (1.5-4 cm), at a median 61 years of age (range = 40-76), participated in this study. Pre-repair RCT tear location/size and 6-month healing status were confirmed by an independent radiologist. Subjects with shorter- (Group 1: 17.8 ± 21 days, n = 37) and longer-term (Group 2: 185.4 ± 89 days, n = 34) shoulder function limitation durations were also compared over 1 year for active mobility, strength, American Shoulder and Elbow Surgeon's Shoulder Score (ASES score), Veterans RAND 12 Item Health Survey (VR-12), and visual analog scale (VAS) pain and instability scores.

RESULTS

Three of the 52 subjects [5.8%] who underwent 6-month MRI experienced a re-tear at the original RCT footprint repair site. By the 1-year follow-up, overall anchor survival was 97%. Although Group 2 displayed lower ASES and VR-12 scores pre-repair (ASES = 40.1 ± 17 vs. 47.9 ± 17; VR-12 physical health (PH) = 37.2 ± 9 vs. 41.4 ± 8) (p ≤ 0.048), at 3-month post-RCT repair (ASES = 61.3 ± 19 vs. 71.3 ± 20; VR-12 PH = 40.8 ± 8 vs. 46.8 ± 9) (p ≤ 0.038), and at 6-month post-RCT repair (ASES = 77.4 ± 18 vs. 87.8 ± 13; VR-12 PH = 48.9 ± 11 vs. 54.0 ± 9) (p ≤ 0.045), by 1-year post-RCT repair, groups did not differ (n.s.). Between-groups VR-12 mental health score differences were not evident at any time period (n.s.). Shoulder pain and instability VAS scores also did not differ (n.s.), displaying comparable improvement between groups from pre-RCT repair to 1-year post-RCT repair. Groups had comparable active shoulder mobility and strength recovery at each follow-up (n.s.).

CONCLUSION

At 6-month post-RCT repair, only 3/52 of patients [5.8%] had a footprint re-tear, and at 1-year follow-up, overall anchor survival was 97%. Use of this scaffold anchor was associated with excellent early clinical outcomes regardless of shoulder function impairment duration.

LEVEL OF EVIDENCE

II.

Nonoperative and Operative Bone and Cartilage Regeneration and Orthopaedic Biologics of the Hip: An Orthoregeneration Network (ON) Foundation Hip Review

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and, optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the hip, including osteonecrosis (aseptic necrosis) involving bone marrow, bone, and cartilage, and chondral injuries involving articular cartilage, synovium, and bone marrow. Promising and established treatment modalities for osteonecrosis include nonweightbearing; pharmacological treatments including low molecular-weight heparin, prostacyclin, statins, bisphosphonates, and denosumab, a receptor activator of nuclear factor-kB ligand inhibitor; extracorporeal shock wave therapy; pulsed electromagnetic fields; core decompression surgery; cellular therapies including bone marrow aspirate comprising mesenchymal stromal cells (MSCs aka mesenchymal stem cells) and bone marrow autologous concentrate, with or without expanded or cultured cells, and possible addition of bone morphogenetic protein-2, vascular endothelial growth factor, and basic fibroblast growth factor; and arterial perfusion of MSCs that may be combined with addition of carriers or scaffolds including autologous MSCs cultured with beta-tricalcium phosphate ceramics associated with a free vascularized fibula. Promising and established treatment modalities for chondral lesions include autologous platelet-rich plasma; hyaluronic acid; MSCs (in expanded or nonexpanded form) derived from bone marrow or other sources such as fat, placenta, umbilical cord blood, synovial membrane, and cartilage; microfracture or microfracture augmented with membrane containing MSCs, collagen, HA, or synthetic polymer; mosaicplasty; 1-stage autologous cartilage translation (ACT) or 2-stage ACT using 3-dimensional spheroids; and autologous cartilage grafting; chondral flap repair, or flap fixation with fibrin glue. Hip pain is catastrophic in young patients, and promising therapies offer an alternative to premature arthroplasty. This may address both physical and psychological components of pain; the goal is to avoid or postpone an artificial joint. LEVEL OF EVIDENCE: Level V, expert opinion.

Why and how to use the body's own stem cells for regeneration in musculoskeletal disorders: a primer

Background

Recently, the management of musculoskeletal disorders with the patients' own stem cells, isolated from the walls of small blood vessels, which can be found in great numbers in the adipose tissue, has received considerable attention. On the other hand, there are still misconceptions about these adipose-derived regenerative cells (ADRCs) that contain vascular-associated pluripotent stem cells (vaPS cells) in regenerative medicine.

Methods

Based on our previous publications on this topic, we have developed a concept to describe the significance of the ADRCs/vaPS cells in the field of orthobiologics as briefly as possible and at the same time as precisely as possible.

Results

The ADRCs/vaPS cells belong to the group of orthobiologics that are based on autologous cells. Because the latter can both stimulate a patient’s body's localized self-healing power and provide new cells that can integrate into the host tissue during the healing response when the localized self-healing power is exhausted, this group of orthobiologics appears more advantageous than cell-free orthobiologics and orthobiologics that are based on allogeneic cells. Within the group of orthobiologics that are based on autologous cells, enzymatically isolated, uncultured ADRCs/vaPS cells have several advantages over non-enzymatically isolated cells/microfragmented fat as well as over uncultured bone marrow aspirate concentrate and cultured cells (adipose-derived stem cells, bone marrow-derived mesenchymal stem cells).

Conclusions

The use of ADRCs/vaPS cells can be seamlessly integrated into modern orthopedic treatment concepts, which can be understood as the optimization of a process which—albeit less efficiently—also takes place physiologically. Accordingly, this new safe and effective type of treatment is attractive in terms of holistic thinking and personalized medicine.