Isolated Osteochondral Autograft Versus Allograft Transplantation for the Treatment of Symptomatic Cartilage Lesions of the Knee: A Systematic Review and Meta-analysis

Glycosphingolipids in Osteoarthritis and Cartilage-Regeneration Therapy: Mechanisms and Therapeutic Prospects Based on a Narrative Review of the Literature

Glycosphingolipids (GSLs), a subtype of glycolipids containing sphingosine, are critical components of vertebrate plasma membranes, playing a pivotal role in cellular signaling and interactions. In human articular cartilage in osteoarthritis (OA), GSL expression is known notably to decrease. This review focuses on the roles of gangliosides, a specific type of GSL, in cartilage degeneration and regeneration, emphasizing their regulatory function in signal transduction. The expression of gangliosides, whether endogenous or augmented exogenously, is regulated at the enzymatic level, targeting specific glycosyltransferases. This regulation has significant implications for the composition of cell-surface gangliosides and their impact on signal transduction in chondrocytes and progenitor cells. Different levels of ganglioside expression can influence signaling pathways in various ways, potentially affecting cell properties, including malignancy. Moreover, gene manipulations against gangliosides have been shown to regulate cartilage metabolisms and chondrocyte differentiation in vivo and in vitro. This review highlights the potential of targeting gangliosides in the development of therapeutic strategies for osteoarthritis and cartilage injury and addresses promising directions for future research and treatment.

Harnessing Nanomedicine for Cartilage Repair: Design Considerations and Recent Advances in Biomaterials

Cartilage injuries are escalating worldwide, particularly in aging society. Given its limited self-healing ability, the repair and regeneration of damaged articular cartilage remain formidable challenges. To address this issue, nanomaterials are leveraged to achieve desirable repair outcomes by enhancing mechanical properties, optimizing drug loading and bioavailability, enabling site-specific and targeted delivery, and orchestrating cell activities at the nanoscale. This review presents a comprehensive survey of recent research in nanomedicine for cartilage repair, with a primary focus on biomaterial design considerations and recent advances. The review commences with an introductory overview of the intricate cartilage microenvironment and further delves into key biomaterial design parameters crucial for treating cartilage damage, including microstructure, surface charge, and active targeting. The focal point of this review lies in recent advances in nano drug delivery systems and nanotechnology-enabled 3D matrices for cartilage repair. We discuss the compositions and properties of these nanomaterials and elucidate how these materials impact the regeneration of damaged cartilage. This review underscores the pivotal role of nanotechnology in improving the efficacy of biomaterials utilized for the treatment of cartilage damage.

The role of autologous bone grafting in matrix-associated autologous chondrocyte implantation at the knee: Results from the German Cartilage Registry (KnorpelRegister DGOU)

PURPOSE

To investigate whether concomitant autologous bone grafting adversely affects clinical outcome and graft survival after matrix-associated autologous chondrocyte implantation (M-ACI).

METHODS

The present study examines registry data of patients who underwent M-ACI with or without autologous bone grafting for large-sized chondral or osteochondral defects. Propensity score matching was performed to exclude potential confounders. A total of 215 patients with similar baseline characteristics were identified. Clinical outcome was assessed at the time of surgery and at 6, 12, 24, 36 and 60 months using the Knee Injury and Osteoarthritis Outcome Score (KOOS). KOOS change, clinical response rate, KOOS subcomponents and failure rate were determined.

RESULTS

Patients treated with M-ACI and autologous bone grafting achieved comparable clinical outcomes compared with M-ACI alone. At 24 months postoperatively, the patient-reported outcome (PRO) of patients treated with M-ACI and autologous bone grafting was even significantly better as measured by KOOS (74.9 ± 18.8 vs. 79.2 ± 15.4; p = 0.043). However, the difference did not exceed the minimal clinically important difference (MCID). In patients with M-ACI and autologous bone grafting, a greater change in KOOS relative to baseline was observed at 6 (9.3 ± 14.7 vs. 15.0 ± 14.7; p = 0.004) and 12 months (12.6 ± 17.2 vs. 17.7 ± 14.6; p = 0.035). Overall, a high clinical response rate was observed in both groups at 24 months (75.8% vs. 82.0%; p = n.s.). The estimated survival at the endpoint of reoperation for any reason was 82.1% (SD 2.8) at 8.4 years for isolated M-ACI and 88.7% (SD 2.4) at 8.2 years for M-ACI with autologous bone grafting (p = 0.039).

CONCLUSIONS

Even in the challenging cohort of large osteochondral defects, the additional treatment with autologous bone grafting leads to remarkably good clinical outcomes in patients treated with M-ACI. In fact, they tend to benefit more from surgery, have lower revision rates and achieve clinical response rates earlier. Subchondral bone management is critical to the success of M-ACI and should be addressed in the treatment of borderline defects.

LEVEL OF EVIDENCE

Level III.

Electrochemical technique to develop surface-controlled polyaniline nano-tulips (PANINTs) on PCL-reinforced chitosan functionalized (CS-f-Fe2O3) scaffolds for stimulating osteoporotic bone regeneration

Bone defects pose significant challenges in orthopedic surgery, often leading to suboptimal outcomes and complications. Addressing these challenges, we employed a three-electrode electrochemical system to fabricate surface-controlled polyaniline nano-tulips (PANINTs) decorated polycaprolactone (PCL) reinforced chitosan functionalized iron oxide nanoparticles (CS-f-Fe2O3) scaffolds. These structures were designed to emulate the natural extracellular matrix (ECM) and promote enhanced osseointegration by establishing a continuous interface between host bone and graft, thereby improving both biological processes and mechanical stability. In vitro experiments demonstrated that PANINTs-PCL/CS-f-Fe2O3 substrates significantly promoted the proliferation, differentiation, and spontaneous outgrowth and extension of MC3T3-E1 cell activity. The nanomaterials exhibited increased cell viability and osteogenic differentiation, as evidenced by elevated expression of bone-related markers such as ALP, ARS, COL-I, RUNX2, and SPP-I, as determined by qRT-PCR. Our findings underscore the regenerative potential of in situ cell culture systems for bone defects, emphasizing the targeted stimulation of essential cell subpopulations to facilitate rapid bone tissue regeneration.

Osteochondral Allograft or Autograft Transplantation of the Femoral Head Leads to Improvement in Outcomes but Variable Survivorship: A Systematic Review

PURPOSE

To review patient-reported outcomes (PROs) and survivorship in patients undergoing osteochondral autograft or allograft transplantation (OAT) of the femoral head.

METHODS

PubMed, Cochrane Center for Register of Controlled Trials, and Scopus databases were searched in November 2022 with an updated search extending to December 2023 using criteria from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the following keywords: (hip OR femoral head) AND (mosaicplasty OR osteochondral allograft OR osteochondral autograft OR osteochondral lesion). Articles were included if they evaluated postoperative PROs in patients who underwent OAT of the femoral head and had a study size of 5 or more hips (n ≥ 5). Survivorship was defined as freedom from conversion to total hip arthroplasty. For PROs evaluated in 3 studies or more, forest plots were created and I2 was calculated.

RESULTS

Twelve studies were included in this review, with a total of 156 hips and a mean follow-up time ranging between 16.8 and 222 months. In total, 104 (66.7%) hips were male while 52 (33.3%) were female. Age of patients ranged from 17.0 to 35.4 years, while body mass index ranged from 23.3 to 28.1. Eight studies reported on osteochondral autograft transplantation and 4 studies on osteochondral allograft transplantation. Three studies reported significant improvement in at least 1 PRO. Survivorship ranged from 61.5% to 96% at minimum 2-year follow-up and from 57.1% to 91% at minimum 5-year follow-up. At a follow-up of less than 5 years, osteochondral allograft transplantation studies showed 70% to 87.5% survivorship, while autograft varied from 61.54% to 96%.

CONCLUSIONS

Patients with osteochondral lesions of the femoral head who underwent osteochondral autograft or allograft transplantation demonstrated improved PROs but variable survivorship rates.

LEVEL OF EVIDENCE

Level IV, systematic review of Level IV studies.

Sericin nano-gel agglomerates mimicking the pericellular matrix induce the condensation of mesenchymal stem cells and trigger cartilage micro-tissue formation without exogenous stimulation of growth factors in vitro

Mesenchymal stem cells (MSCs) are excellent seed cells for cartilage tissue engineering and regenerative medicine. Though the condensation of MSCs is the first step of their differentiation into chondrocytes in skeletal development, the process is a challenge in cartilage repairing by MSCs. The pericellular matrix (PCM), a distinct region surrounding the chondrocytes, acts as an extracellular linker among cells and forms the microenvironment of chondrocytes. Inspired by this, sericin nano-gel soft-agglomerates were prepared and used as linkers to induce MSCs to assemble into micro-spheres and differentiate into cartilage-like micro-tissues without exogenous stimulation of growth factors. These sericin nano-gel soft-agglomerates are composed of sericin nano-gels prepared by the chelation of metal ions and sericin protein. The MSCs cultured on 2D culture plates self-assembled into cell-microspheres centered by sericin nano-gel agglomerates. The self-assembly progress of MSCs is superior to the traditional centrifugation to achieve MSC condensation due to its facility, friendliness to MSCs and avoidance of the side-effects of growth factors. The analysis of transcriptomic results suggested that sericin nano-gel agglomerates offered a soft mechanical stimulation to MSCs similar to that of the PCM to chondrocytes and triggered some signaling pathways as associated with MSC chondrogenesis. The strategy of utilizing biomaterials to mimic the PCM as a linker and as a mechanical micro-environment and to induce cell aggregation and trigger the differentiation of MSCs can be employed to drive 3D cellular organization and micro-tissue fabrication in vitro. These cartilage micro-masses reported in this study can be potential candidates for cartilage repairing, cellular building blocks for 3D bio-printing and a model for cartilage development and drug screening.

3D Printing of Microenvironment-Specific Bioinspired and Exosome-Reinforced Hydrogel Scaffolds for Efficient Cartilage and Subchondral Bone Regeneration

In clinical practice, repairing osteochondral defects presents a challenge due to the varying biological properties of articular cartilages and subchondral bones. Thus, elucidating how spatial microenvironment-specific biomimetic scaffolds can be used to simultaneously regenerate osteochondral tissue is an important research topic. Herein, a novel bioinspired double-network hydrogel scaffold produced via 3D printing with tissue-specific decellularized extracellular matrix (dECM) and human adipose mesenchymal stem cell (MSC)-derived exosomes is described. The bionic hydrogel scaffolds promote rat bone marrow MSC attachment, spread, migration, proliferation, and chondrogenic and osteogenic differentiation in vitro, as determined based on the sustained release of bioactive exosomes. Furthermore, the 3D-printed microenvironment-specific heterogeneous bilayer scaffolds efficiently accelerate the simultaneous regeneration of cartilage and subchondral bone tissues in a rat preclinical model. In conclusion, 3D dECM-based microenvironment-specific biomimetics encapsulated with bioactive exosomes can serve as a novel cell-free recipe for stem cell therapy when treating injured or degenerative joints. This strategy provides a promising platform for complex zonal tissue regeneration whilst holding attractive clinical translation potential.

Outcomes of Plug Osteochondral Allograft Transplantation With or Without Concomitant Osteotomy for Cartilage Defects in the Knee: Minimum 2-year Follow-up

INTRODUCTION

Isolated osteochondral defects of the knee can cause notable pain and disability. Osteochondral allograft (OCA) transplantation using trephined plug grafts is a highly effective, often curative, treatment option. In knees with malalignment into the transplanted compartment, osteotomy can be done concurrently. This study investigates early-to-midterm survivorship, as well as clinical and radiographic outcomes, of plug OCAs with and without concomitant osteotomy in the knee.

METHODS

Plug OCA was done on active, young to middle-aged patients with osteochondral defects ≤4 cm diameter. Prospectively collected data for 102 patients who underwent plug OCA between 2004 and 2020 were reviewed. Survivorship according to Kaplan-Meier analysis was the primary outcome. Failure was defined as conversion to total knee arthroplasty or repeat allograft. Clinical and radiographic outcomes were evaluated using the modified Hospital for Special Surgery (mHSS) score and Kellgren-Lawrence grading.

RESULTS

Eighty-six patients with a mean age of 29 ± 9.7 years (15 to 54) and a mean follow-up of 6.8 ± 3.7 years (2 to 15.9) were studied. Concomitant realignment osteotomy was done in 66 patients (76.7%). Graft survivorship was 100%, 93.8% (95% confidence interval 90.8% to 96.8%), and 89.7% (95% confidence interval 85.6% to 93.8%) at 2, 5, and 10 to 15 years, respectively. Six grafts (7.0%) required knee arthroplasty at a mean of 4.6 ± 1.8 years (2.2 to 7.1). Most common reasons for revision surgeries with graft retention included implant removal (11.6%), débridement (8.1%), and repeat osteotomy (5.8%). The mean mHSS score of 90.8 ± 10.4 (51 to 100) at the final follow-up was significantly higher than the preoperative value of 72.5 ± 12.1 (36 to 90) (P < 0.001). Subgroup analyses revealed a markedly greater risk of failure in grafts with a diameter of 30 mm or larger.

DISCUSSION

Plug OCA with or without concurrent realignment osteotomy resulted in an excellent graft survival of 93% at a mean of 6.8 years, with reliable functional improvement demonstrated by notable improvements in mHSS knee scores.

Chitosan based scaffold applied in patellar cartilage lesions showed positive clinical and MRI results at minimum 2 years of follow up

PURPOSE

New scaffold-based cartilage regeneration techniques have been developed to improve the results of microfractures also in complex locations like the patello-femoral joint. The aim of this study was to analyse the results obtained in patellar lesions treated with a bioscaffold,  a mixture composed by a chitosan solution, a buffer, and the patient's whole blood  which forms a stable clot into the lesion.

METHODS

Fifteen patients with ICRS grade 3-4 cartilage lesions of the patellar surface were treated with a chitosan bioscaffold. Fourteen patients were clinically and radiologically evaluated prospectively for a minimum follow-up of 2 years with IKDC, KOOS, Tegner score, and MRI. The mean age of patients at the time of surgery was 31.8 ± 11.9 and nine patients presented degenerative aetiology, four patients with previous trauma, and 1 patient with osteochondritis dissecans.  RESULTS: The IKDC subjective score improved from 46.2 ± 19.3 preoperatively to 69.5 ± 20.3 (p < 0.05) and 74.1 ± 23.2 (p < 0.05) at 12 and 24 months, respectively. Also KOOS Pain, KOOS Sport/Rec and KOOS QOL showed a significant improvement from baseline to 12 months and to the final follow-up. MRI evaluation showed a complete filling of the cartilage defect at the final follow-up in 70% of the lesions, obtaining a total MOCART 2.0 score of 71.5 ± 13.6 at 24 months after surgery.

CONCLUSION

Chondral patellar lesions represent a complex pathology, with lower results compared to other sites. This bioscaffold represents a safe surgical treatment providing a significant clinical improvement at 24 months in the treatment of patellar cartilage lesions.

LEVEL OF EVIDENCE

IV.