Ortho-Biologics for Ligament Repair and Reconstruction

Evaluation of tendon and ligament microstructure and mechanical properties in a canine model of mucopolysaccharidosis I

Mucopolysaccharidosis (MPS) I is a lysosomal storage disorder characterized by deficient alpha-l-iduronidase activity, leading to abnormal accumulation of glycosaminoglycans (GAGs) in cells and tissues. Synovial joint disease is prevalent and significantly reduces patient quality of life. There is a strong clinical need for improved treatment approaches that specifically target joint tissues; however, their development is hampered by poor understanding of underlying disease pathophysiology, including how pathological changes to component tissues contribute to overall joint dysfunction. Ligaments and tendons, in particular, have received very little attention, despite the critical roles of these tissues in joint stability and biomechanical function. The goal of this study was to leverage the naturally canine model to undertake functional and structural assessments of the anterior (cranial) cruciate ligament (CCL) and Achilles tendon in MPS I. Tissues were obtained postmortem from 12-month-old MPS I and control dogs and tested to failure in uniaxial tension. Both CCLs and Achilles tendons from MPS I animals exhibited significantly lower stiffness and failure properties compared to those from healthy controls. Histological examination revealed multiple pathological abnormalities, including collagen fiber disorganization, increased cellularity and vascularity, and elevated GAG content in both tissues. Clinically, animals exhibited mobility deficits, including abnormal gait, which was associated with hyperextensibility of the stifle and hock joints. These findings demonstrate that pathological changes to both ligaments and tendons contribute to abnormal joint function in MPS I, and suggest that effective clinical management of joint disease in patients should incorporate treatments targeting these tissues.

Prospective Randomized Trial of Biologic Augmentation With Bone Marrow Aspirate Concentrate in Patients Undergoing Arthroscopic Rotator Cuff Repair

BACKGROUND

Although initial studies have demonstrated that concentrated bone marrow aspirate (cBMA) injections promote rotator cuff repair (RCR) healing, there are no randomized prospective studies investigating clinical efficacy.

HYPOTHESIS/PURPOSE

To compare outcomes after arthroscopic RCR (aRCR) with and without cBMA augmentation. It was hypothesized that cBMA augmentation would result in statistically significant improvements in clinical outcomes and rotator cuff structural integrity.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Patients indicated for aRCR of isolated 1- to 3-cm supraspinatus tendon tears were randomized to receive adjunctive cBMA injection or sham incision. Bone marrow was aspirated from the iliac crest, concentrated using a commercially available system, and injected at the aRCR site after repair. Patients were assessed preoperatively and serially until 2 years postoperatively via the following functional indices: American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), Simple Shoulder Test, 12-Item Short Form Health Survey, and Veterans RAND 12-Item Health Survey. Magnetic resonance imaging (MRI) was performed at 1 year to assess rotator cuff structural integrity according to Sugaya classification. Treatment failure was defined as decreased 1- or 2-year ASES or SANE scores as compared with preoperative baseline, the need for revision RCR, or conversion to total shoulder arthroplasty.

RESULTS

An overall 91 patients were enrolled (control, n = 45; cBMA, n = 46): 82 (90%) completed 2-year clinical follow-up and 75 (82%) completed 1-year MRI. Functional indices significantly improved in both groups by 6 months and were sustained at 1 and 2 years (all P < .05). The control group showed significantly greater evidence of rotator cuff retear according to Sugaya classification on 1-year MRI (57% vs 18%; P < .001). Treatment failed for 7 patients in each group (control, 16%; cBMA, 15%).

CONCLUSION

cBMA-augmented aRCR of isolated supraspinatus tendon tears may result in a structurally superior repair but largely fails to significantly improve treatment failure rates and patient-reported clinical outcomes when compared with aRCR alone. Additional study is warranted to investigate the long-term benefits of improved repair quality on clinical outcomes and repair failure rates.

REGISTRATION

NCT02484950 (ClinicalTrials.gov identifier).

Advanced Gene Therapy Strategies for the Repair of ACL Injuries

The anterior cruciate ligament (ACL), the principal ligament for stabilization of the knee, is highly predisposed to injury in the human population. As a result of its poor intrinsic healing capacities, surgical intervention is generally necessary to repair ACL lesions, yet the outcomes are never fully satisfactory in terms of long-lasting, complete, and safe repair. Gene therapy, based on the transfer of therapeutic genetic sequences via a gene vector, is a potent tool to durably and adeptly enhance the processes of ACL repair and has been reported for its workability in various experimental models relevant to ACL injuries in vitro, in situ, and in vivo. As critical hurdles to the effective and safe translation of gene therapy for clinical applications still remain, including physiological barriers and host immune responses, biomaterial-guided gene therapy inspired by drug delivery systems has been further developed to protect and improve the classical procedures of gene transfer in the future treatment of ACL injuries in patients, as critically presented here.

Study protocol for double-blind, randomised placebo-controlled trial evaluating semitendinosus function and morbidity following tendon harvesting for anterior cruciate ligament reconstruction augmented by platelet-rich plasma

INTRODUCTION

Anterior cruciate ligament (ACL) rupture is debilitating, often requiring surgical reconstruction. An ACL reconstruction (ACLR) using a tendon autograft harvested from the semitendinosus results in substantial injury to the donor muscle. Following ACLR, patients rarely return to their preinjury level of physical activity, are at elevated risk of secondary lower limb injuries and early onset knee osteoarthritis. To date, no randomised controlled trial has evaluated the efficacy of platelet-rich plasma (PRP) in aiding knee function and semitendinosus morphology of following ALCR.

METHODS AND ANALYSIS

This is a multicentre double-blind randomised placebo-controlled trial. Fifty-four ACLR patients aged 18-50 years will be randomised to receive either a single application of PRP (ACLR+) or placebo saline (ACLR) into the semitendinosus harvest zone at the time of surgery. All patients will undergo normal postoperative rehabilitation recommended by the attending orthopaedic surgeon or physiotherapist. The primary outcome measure is between-limb difference (ACLR compared with intact contralateral) in isometric knee flexor strength at 60o knee flexion, collected 10-12 months postsurgery. This primary outcome measure will be statistically compared between groups (ACLR+ and standard ACLR). Secondary outcome measures include bilateral assessments of hamstring muscle morphology via MRI, biomechanical and electromyographic parameters during an anticipated 45° running side-step cut and multidirectional hopping task and patient-reported outcomes questionaries. Additionally, patient-reported outcomes questionaries will be collected before (baseline) as well as immediately after surgery, and at 2-6 weeks, 3-4 months, 10-12 months and 22-24 months postsurgery 10-12 months following surgery.

ETHICS AND DISSEMINATION

Ethics approval has been granted by Griffith University Human Research Ethics Committee, Greenslopes Research and Ethics Committee, and Royal Brisbane & Women's Hospital Human Research Ethics Committee. Results will be submitted for publication in a peer-reviewed medical journal.

TRIAL REGISTRATION NUMBER

ACTRN12618000762257p.

Application of Biomaterials in Prevention and Treatment of Calf Tendon Injury in Football Games

Football sports can easily lead to a calf strain and tendon damage. To this end, we explored the therapeutic effect of sodium hyaluronate biomaterial-assisted micro-suturing in treating calf tendon injury after football sports. Given this, we will group the patients to compare the test and conduct the efficacy analysis. One group was sutured by ordinary microsurgery. The other was sutured and combined with sodium hyaluronate treatment. The study found that there were statistical differences in tendon recovery between the two groups of patients. Sodium hyaluronate biomaterial can improve the treatment effect of calf tendon injury in football sports. This biological material is worthy of clinical application.

Cellular Augmentation of Anterior Cruciate Ligament Surgery Is Not Currently Evidence Based: A Systematic Review of Clinical Studies

PURPOSE

To perform a systematic review of clinical outcome studies exploring cellular augmentation of anterior cruciate ligament (ACL) surgery, including stem cell techniques.

METHODS

A systematic search was performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) guidelines using the Cochrane, PubMed, MEDLINE, SPORTDiscus, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases from 2000 to 2019. The inclusion criteria were clinical studies that reported on ACL surgery augmented with stem cells or cellular therapy and patient-reported outcome measures or graft healing. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized clinical trials, and nonrandomized trials were assessed using the Methodological Items for Non-randomized Studies (MINORS) tool. Methodologic assessment was performed according to the Modified Coleman Methodology Score.

RESULTS

Four studies were found: 2 randomized clinical trials, 1 cohort study with a matched historical control group, and 1 case series. The mean Modified Coleman Methodology Score in these studies was 59, and there was a low risk of bias in 1 study. One study reported outcomes of augmented ACL repair, and 3 studies reported the results of augmented ACL reconstruction. Cellular therapies varied and included concentrated bone marrow aspirate, collagenase/centrifuge processed adipose, and marrow stimulation combined with platelet-rich plasma, as well as cells cultured from allograft bone marrow aspirate. The concentrated bone marrow aspirate and adipose tissue study results did not support their use. The marrow stimulation technique combined with repair led to promising clinical results. The use of allograft cultured cells improved patient-reported outcomes and postoperative radiographic findings.

CONCLUSIONS

Augmentation of ACL surgery with cellular therapy is not supported by clinical evidence at this time.

LEVEL OF EVIDENCE

Level IV.

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

Orthoregeneration is defined as a solution for orthopedic 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 electro-magnetic 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 knee, including symptomatic osteoarthritis and chondral injuries, as well as injuries to tendon, meniscus, and ligament, including the anterior cruciate ligament. Promising and established treatment modalities include hyaluronic acid (HA) in liquid or scaffold form; platelet-rich plasma (PRP); bone marrow aspirate (BMA) comprising mesenchymal stromal cells (MSCs), hematopoietic stem cells, endothelial progenitor cells, and growth factors; connective tissue progenitor cells (CTPs) including adipose-derived mesenchymal stem cells (AD-MSCs) and tendon-derived stem cells (TDSCs); matrix cell-based therapy including autologous chondrocytes or allograft; vitamin D; and fibrin clot. Future investigations should standardize solution preparations, because inconsistent results reported may be due to heterogeneity of HA, PRP, BMAC, or MSC preparations and regimens, which may inhibit meaningful comparison between studies to determine the true efficacy and safety for each treatment.

Effectiveness of Platelet-Rich Plasma and Bone Marrow Aspirate Concentrate as Treatments for Chronic Hindlimb Proximal Suspensory Desmopathy

This retrospective study aimed to evaluate the clinical effect of bone marrow aspirate concentrate (BMAC) and leukocyte rich PRP (LR-PRP) compared to horses undergoing controlled exercise alone in horses with >3 months proximal suspensory desmopathy in hindlimbs (HPSD). Nighty-three horses were divided into three groups according to the treatment: a control (n = 22), LR-PRP (n = 46), and BMAC (n = 25) group. Lameness and ultrasound scores were recorded before treatment (T0) and at 6 months (T1) post-treatment. Records horses considered sound at evaluation and level of performance were additionally registered at 12 months (T2) and 18 months (T3) after treatment. The BMAC cytology profiles from 22 horses were also analysed and compared to clinical outcomes. The results at T1 showed that 9% (2/22) of the horses in the control group were sound compared to 59% (25/46) and 84% (21/25) in the LR-PRP and BMAC groups, respectively. Additionally, ultrasound scores at T1 in the BMAC and LR-PRP groups were improved in comparison with the control group (p = 0.02). At T2, 68% of the horses in the BMAC group and 39% of the horses in the LR-PRP group had returned to the previous performance level. At T3, a significantly higher percentage of horses in the LR-PRP (43%) and BMAC (72%) group were sound when compared to the control (4.6%) group (p = 0.02). Similarly, at T3, significantly more horses of the BMAC (16/25) and of the LR-PRP (15/46) group had returned to the previous or a higher performance level compared to the control (1/22) group (p = 0.01). No correlation was found between long-term clinical outcome and cytology profiles in the BMAC group. In conclusion, long-term outcomes of treatment with LR-PRP or BMAC are significantly better than conventional treatment of the hindlimb chronic PSD in horses. Additionally, BMAC yielded better lameness scores than LR-PRP at short- and long-term follow-up.

Treatment of Partial Posterior Cruciate Ligament Injuries with Platelet-Rich Plasma in Growth Factors (PRGF) Intraligamentous Infiltration and a Specific Knee Brace

Posterior cruciate ligament (PCL) injuries are not as common as other knee ligament injuries, but may present a challenging scenario for even skilled knee surgeons. Complete PCL tears are typically encountered in the setting of multiligament knee injuries and require surgical treatment. Isolated complete PCL injuries are uncommon and the best treatment is debated, and likely depends on the degree of symptoms and objective instability. However, many PCL injuries will be partial tears (grade I or II). The purpose of this chapter is to describe our treatment of choice for partial PCL injuries through a conservative approach.

Level of evidence  Level IV.