Combined autologous chondrocyte implantation and meniscus reconstruction for large chondral defect in the lateral compartment due to discoid lateral meniscus tear: A case report

Autologous Chondrocyte Implantation With Collagen Membrane Using a Knotless Suture Bridge Technique

Autologous chondrocyte implantation (ACI) has been covered by insurance in Japan since April 2013, expanding the range of treatments for extensive knee cartilage damage. Initially, the periosteum was used for the fixation of cultured cartilage, but since February 2019, the introduction of collagen membranes has shortened surgery time and simplified the procedure. We report a case where we used the knotless suture bridge technique for a more straightforward and secure fixation with a collagen membrane. The patient was a 61-year-old male who experienced right knee pain a year earlier when stepping downstairs. Conservative treatment at a local hospital was ineffective, and he was referred to our department. At the initial examination, the right knee had an extension of -5° and a flexion of 130°. A simple X-ray of the right knee showed osteosclerosis with a translucent bone image at the medial femoral condyle. Weight-bearing full-length X-ray of the lower limb showed a femorotibial angle (FTA) of 186°, a hip-knee-ankle (HKA) angle of 12.5° varus, a percentage of mechanical axis (%MA) of 15%, and a medial proximal tibial angle (MPTA) of 78°, indicating a significant varus deformity. CT and MRI revealed a cartilage defect of 36 mm in length and 16 mm in width and a bone defect with a maximum depth of 15 mm at the medial femoral condyle. The patient underwent surgery for a traumatic cartilage defect of the medial femoral condyle. For the bone defect, autologous bone grafting was performed, and for the cartilage defect, ACI was done. The ACI involved fixation with a collagen membrane using 1.3 mm suture tape and BC PushLock anchor (Arthrex, Naples, Florida, United States) in a knotless suture bridge technique. Additionally, hybrid closed-wedge high tibial osteotomy (HCWHTO) was performed for alignment correction. At eight months post surgery, MRI proton density sagittal images confirmed the joint surface by the cartilage layer, and the Modified Outerbridge Cartilage Repair Assessment (MOCART) score was 80. At 12 months post surgery, the Japanese version of the Knee Injury and Osteoarthritis Outcome Score (J-KOOS) improved from 46.43 to 82.14 for symptoms, 58.33 to 83.33 for pain, 95.59 to 100 for activities of daily living (ADL), 45 to 75 for sports, and 68.75 to 87.50 for quality of life (QOL). X-rays showed an FTA of 173°, an HKA of 0°, and a %MA of 58%, indicating a favorable course. The knotless suture bridge technique for collagen membrane fixation during ACI is considered a convenient and time-saving method.

In vitro and in vivo efficacy of naturally derived scaffolds for cartilage repair and regeneration

Intrinsically present bioactive cues allow naturally derived materials to mimic important characteristics of cartilage while also facilitating cellular recruitment, infiltration, and differentiation. Such traits are often what tissue engineers desire when they fabricate scaffolds, and yet, literature from the past decade is replete with examples of how most natural constructs with native biomolecules have only offered sub-optimal results in the treatment of cartilage defects. This paper provides an in-depth investigation of the performance of such scaffolds through a review of a collection of natural materials that have been used so far in repairing/regenerating articular cartilage. Although in vivo and clinical studies are the best indicators of scaffold efficacy, it was, however, observed that a large number of natural constructs had very promising scaffold characteristics to begin with, and would often show good in vitro/in vivo results. Finally, an examination of the biochemistry and biomechanics of repair tissues in studies that reported positive outcomes showed that these attributes often approached target cartilage values. The paper concludes with an outline of current trends as well as future directions for the field. STATEMENT OF SIGNIFICANCE: This review offers an exclusive focus on natural scaffold materials for cartilage repair and regeneration and provides a quantitative and qualitative analysis of their performance under a variety of in vitro and in vivo conditions. Readers can learn about environments where natural scaffolds have had the most success and tailor strategies to optimize their own work. Furthermore, given how the glycosaminoglycan (GAG) to hydroxyproline (HYP) ratio and moduli are fundamental attributes of hyaline cartilage, this paper adds to the body of knowledge by exploring how these characteristics reflect in preclinical outcomes. Such perspectives can greatly aid researchers better utilize natural materials for Cartilage Tissue Engineering (CTE).

Orthopedic Treatment of Pycnodysostosis: A Systematic Review

Pycnodysostosis (PYCD) is an autosomal recessive lysosomal storage disorder of the bone which leads to stereotypical abnormalities consisting of, but not limited to, sclerotic and fragile bone, shortened distal phalanges, and obtuse mandibular angle. Current literature describes the otolaryngological manifestations and treatment of this disorder; however, the treatment of orthopedic fractures in PYCD patients is seldom described and remains a controversial topic. We aim to systematically review the current evidence regarding the optimal treatment of PYCD patients with fractures.

We performed a literature search using PubMed, MEDLINE, Web of Science, and Google Scholar databases. Elig­ibility criteria consisted of English-language literature of PYCD patients undergoing treatment for orthopedic surgery fractures. Non-English papers or literature focused on maxillofacial manifestations/treatment were excluded.

The database search resulted in the identification of 500 articles. After removing duplicates and enforcing our inclusion criteria, 29 case reports/series (40 patients) were included. The average age was 31.25 (­±18.2) years, with 57.5% of patients being female. Overall, 62.5% of patients had consanguineous parents. Additionally, 86.2% reported a history of previous fractures while 47.5% reported a spontaneous or minor trauma fracture, with most fractures occurring in the femur (60.0%) and tibia (40.0%). Radiographic features consisted of densification in the femur 45.0% (18/40), tibia 37.5% (15/40), and spine 25.0% (10/40). Overall, 84.2% of patients were treated with surgical management consisting of internal plate fixation (IPF) (48.3%), intramedullary fixation (20.7%), and Ilizarov external fixation (IEF) (13.8%). Overall, the refracture rate was 25.0% and was lowest in intramedullary fixation (0/6), compared to IPF (3/14) and IEF (3/4). Average time until refracture was 40.6 months (3-132 months).

Long-term follow-up is recommended in patients with PYCD due to the propensity for fractures/refractures. While this study provides the groundwork for the treatment of PYCD patients, further research with higher-evidence studies should be conducted to establish the optimal orthopedic treatment of this disorder.

Effect of Platelet-Rich Plasma on Autologous Chondrocyte Implantation for Chondral Defects: Results Using an In Vivo Rabbit Model

Background:

Articular cartilage repair remains challenging despite the availability of techniques, including autologous chondrocyte implantation (ACI) for repairing large cartilage defects. Platelet-rich plasma (PRP) therapy, a novel therapy focused on chondrocyte regeneration, needs to be investigated regarding its potential to improve the outcomes of ACI.

Purpose:

To examine the effect of PRP therapy on the outcomes of cartilage repair using the ACI procedure in a rabbit model of knee joint cartilage damage.

Study Design:

Controlled laboratory study.

Methods:

A total of 30 knees in 15 Japanese White rabbits (joint cartilage damage model) were divided into nontreatment (n = 7), PRP (n = 8), ACI (n = 7), and combined ACI and PRP (n = 8) groups. At 4 weeks and 12 weeks postoperatively, histological and visual examination of the surgical site was performed, and the regenerated cartilage and calcified bone areas were measured by imaging the specimens.

Results:

Pretransplantation evaluation in the cultured cartilage showed the histological properties of hyaline cartilage. At 4 weeks postoperatively, the regenerated cartilage area at the surgical site showed a larger safranin O–positive area in the ACI group (2.73 ± 4.46 mm²) than in the combined ACI and PRP group (1.71 ± 2.04 mm²). Calcified bone formation in the ACI group was relatively lower than that in the other groups. Cartilage repair failure occurred in all groups at 12 weeks postoperatively.

Conclusion:

The authors found no positive effects of PRP on the outcomes of ACI in a rabbit model. There was a smaller safranin O–positive region with the addition of PRP to ACI compared with ACI alone. In the subchondral bone, bone formation might have been promoted by PRP.

Clinical Relevance:

Administering PRP at the time of ACI may not have a positive effect and may have deleterious effects on cartilage engraftment and regeneration.