Assessment of Cartilage Growth After Biopsy of Osteochondral Loose Bodies in Adolescent Knees for Use in Autologous Chondrocyte Implantation

What is New in Pediatric Orthopaedic: Basic Science

BACKGROUND

An understanding of musculoskeletal basic science underpins most advancements in the field of orthopaedic surgery. Knowledge of biomechanics, genetics, and molecular pathways is integral to the understanding of the pathophysiology of disease and guides novel treatment options to improve patient outcomes. The purpose of this review is to provide a comprehensive and current overview of musculoskeletal basic science relevant to pediatric orthopaedic surgery.

METHODS

Comprehensive Pubmed database searches were performed for all English language articles published between January 2016 and November 2021 using the following search terms: basic science, pediatric orthopaedics, fracture, trauma, spine, scoliosis, DDH, hip dysplasia, Perthes, Legg-Calve-Perthes, clubfoot, and sports medicine. Inclusion criteria focused on basic science studies of pediatric orthopaedic conditions. Clinical studies or case reports were excluded. A total of 3855 articles were retrieved. After removing duplicates and those failing to meet our inclusion criteria, 49 articles were included in the final review.

RESULTS

A total of 49 papers were selected for review based on the date of publication and updated findings. Findings are discussed in the subheadings below. Articles were then sorted into the following sub-disciplines of pediatric orthopaedics: spine, trauma, sports medicine, hip, and foot.

CONCLUSIONS

With this review, we have identified many exciting developments in pediatric orthopaedic trauma, spine, hip, foot, and sports medicine that could potentially lead to changes in disease management and how we think of these processes.

LEVEL OF EVIDENCE

Level V.

Loose Body Versus Trochlear Biopsy Matrix-Induced Autologous Chondrocyte Implantation (MACI) MOCART Scores and IKDC Reported Outcomes in Pediatric Patients

BACKGROUND

Matrix-induced autologous chondrocyte implantation (MACI) has shown promising results in the treatment of osteochondral lesions of the knee. A recent study showed similar viability comparing chondrocytes harvested from the intercondylar notch compared to those harvested from osteochondral loose bodies. However, there is limited evidence assessing how these different biopsies perform clinically. The goal of this study was to compare both radiographic and patient-reported outcomes in patients with patellar and femoral osteochondral lesions treated with MACI using either a standard intercondylar notch biopsy or an osteochondral loose body biopsy.

METHODS

A retrospective study was performed on all pediatric autologous chondrocyte implantation procedures performed from 2014 to 2017 at a single institution. Patients were divided into 2 groups: one group had cartilage derived from a standard intercondylar notch biopsy (n=9) and the other group had cartilage derived from an osteochondral loose body found within the ipsilateral knee (n=10). At a minimum of 1-year postimplantation, magnetic resonance imagings of the operative knee were performed and the Magnetic Resonance Observation of Cartilage Repair Tissue Knee Score (MOCART 2.0) knee score was used to assess the integrity and quality of the cartilage repair tissue. Interclass correlation coefficients were calculated between the 2 groups. International Knee Documentation Committee (IKDC) outcome scores were determined at a minimum 2 years post-implantation.

RESULTS

The interclass correlation coefficient between three independent examiners for the MOCART scoring was excellent at 0.94. With regards to the MOCART score, the loose body group had an insignificant 17-point lower median score at 63 [interquartile range (IQR): 58 to 89] compared to the intercondylar group at 80 (IQR: 65 to 90) ( P =0.15). There was no difference in IKDC scores with the loose body group having a median score of 82 (IQR: 65 to 95) and the intercondylar group having a median score of 84 (IQR: 53 to 99) ( P =0.90).

CONCLUSION

These results demonstrate that osteochondral loose bodies can be used as viable harvest site in MACI procedures with no difference in functional and radiographic outcomes at 2 years postimplantation. This may limit both short and long-term donor site morbidity.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Assessment and Management of Loose Bodies in the Knee Joint and Related Disease: A Narrative Review

BACKGROUND

Loose bodies are frequently encountered during clinical activity and a common finding during knee arthroscopy. Usually, treatment consists of the removal of the loose bodies, which can be challenging even for experienced surgeons. The excision alone is not always the complete treatment, because loose bodies are generally secondary to other diseases that can cause persistent symptoms with the risk of new loose body formation. The aim of this narrative review is to show the clinical, imaging and arthroscopic evaluation of loose bodies in order to plan optimal treatment.

METHODS

A comprehensive search of PubMed was conducted to find the most recent and relevant studies investigating the aetiopathogenesis, the assessment tools and the therapeutic strategies for knee loose bodies and their related diseases.

RESULTS

When dealing with a loose body, the first issue is the evaluation of the intra-articular fragment (location, size, number, symptoms) and its aetiopathogenesis by identifying the underlying pathology (e.g., osteochondritis dissecans, osteoarthritis, chondral defect, tumour-like lesions, rheumatoid arthritis, etc.). In the case of symptomatic intra-articular loose bodies, treatment consists of fragment removal and the management of related diseases (e.g., lifestyle modification, physiotherapy, pharmacological and surgical treatment).

CONCLUSION

Loose bodies are not separate entities and in addition to their pathological aspect, must be evaluated within the context of the underlying disease. Correct assessment and comprehensive management allow for relief of symptomatology and prevention of loose body formation by removal and treatment of the associated diseases.

Three-Year Outcomes After MACI for Glenoid Cartilage Loss in an Adolescent Athlete: A Case Report

CASE

We report the 3-year outcomes of a 14-year-old boy who anteriorly dislocated his shoulder playing football and suffered a 9-cm2 chondral defect of the anterior glenoid and subsequently treated with matrix-applied characterized autologous chondrocytes (MACI) of the defect with open labral repair.

CONCLUSION

The management of glenohumeral chondral lesions in adolescent patients remains a challenge. Our case of the successful treatment of a glenoid chondral defect with MACI offers hope as a potential treatment option for adolescent patients with this challenging problem.

Clinical and Radiographic Outcomes After Fixation of Chondral Fragments of the Knee in 6 Adolescents Using Autologous Bone Pegs

Background:

Little is known regarding the optimal treatment for displaced, purely chondral fragments in the knee.

Purpose:

To report the clinical and radiographic outcomes of chondral fragment fixation in adolescents through use of autologous bone pegs.

Study Design:

Case series; Level of evidence, 4.

Methods:

This retrospective, single-center study evaluated 6 patients (mean age, 12.9 years) who underwent fixation of chondral fragments (no visualized bone attached) using autologous bone pegs (mean postoperative follow-up, 5.2 years; range, 1.4-10.9 years). The causes were trauma (n = 5) and osteochondritis dissecans (n = 1). Lesions were located in the trochlear groove (lateral, n = 3; medial, n = 2) or posterior part of the lateral femoral condyle (n = 1). The mean lesion size was 3.8 cm² (range, 0.8-9.0 cm²). Patients were evaluated via physical examination and magnetic resonance imaging (MRI) using magnetic resonance observation of cartilage repair tissue scores.

Results:

In total, 5 patients successfully returned to sports without restrictions at a mean of 7 months (range, 6-8 months) postoperatively. At the latest follow-up, these 5 patients had full range of motion and no joint effusion. The mean magnetic resonance observation of cartilage repair tissue score was 85 (range, 70-95) at a mean duration of 3 years (range, 1-5 years). One patient experienced failure at 1.3 years postoperatively after a traumatic injury and subsequently underwent removal of the fixed fragment and a drilling procedure.

Conclusion:

In most adolescents, fixation of chondral fragments with no visualized bony portion using autologous bone pegs provided a satisfactory success rate and good healing of cartilage tissue confirmed on MRI scans.

Inflammation-Modulating Hydrogels for Osteoarthritis Cartilage Tissue Engineering

Osteoarthritis (OA) is the most common form of the joint disease associated with age, obesity, and traumatic injury. It is a disabling degenerative disease that affects synovial joints and leads to cartilage deterioration. Despite the prevalence of this disease, the understanding of OA pathophysiology is still incomplete. However, the onset and progression of OA are heavily associated with the inflammation of the joint. Therefore, studies on OA treatment have sought to intra-articularly deliver anti-inflammatory drugs, proteins, genes, or cells to locally control inflammation in OA joints. These therapeutics have been delivered alone or increasingly, in delivery vehicles for sustained release. The use of hydrogels in OA treatment can extend beyond the delivery of anti-inflammatory components to have inherent immunomodulatory function via regulating immune cell polarization and activity. Currently, such immunomodulatory biomaterials are being developed for other applications, which can be translated into OA therapy. Moreover, anabolic and proliferative levels of OA chondrocytes are low, except initially, when chondrocytes temporarily increase anabolism and proliferation in response to structural changes in their extracellular environment. Therefore, treatments need to restore matrix protein synthesis and proliferation to healthy levels to reverse OA-induced damage. In conjugation with injectable and/or adhesive hydrogels that promote cartilage tissue regeneration, immunomodulatory tissue engineering solutions will have robust potential in OA treatment. This review describes the disease, its current and future immunomodulatory therapies as well as cartilage-regenerative injectable and adhesive hydrogels.