Treating chondral and osteochondral defects in the knee has long been a challenge in orthopedic surgery. Traditional methods often result in the formation of fibrocartilage, a repair tissue that lacks the biomechanical strength and durability of the native hyaline cartilage, leading to poor long-term outcomes and potential secondary arthritis. The article, “TruFit CB© Bone Plug: Chondral Repair, Scaffold Design, Surgical Technique, and Early Experiences,” introduces a promising new solution: a synthetic, acellular scaffold designed to promote the growth of superior repair tissue.
Advanced Scaffold Design for Cartilage Regeneration
The TruFit CB plug is a unique synthetic scaffold created from a polylactide-coglycolide copolymer. It features a biphasic design, with a porous bone phase containing calcium sulfate and a cartilage phase. This design allows for the integration of cells and growth factors from the patient’s own bone marrow, which are essential for stimulating tissue regeneration. By acting as a temporary, three-dimensional structure, the plug provides the necessary support for new tissue to form within the defect. The scaffold gradually resorbs over time, leaving behind a new, functional cartilage layer.
Surgical Technique and Early Results
The article provides a detailed description of the surgical technique for implanting the TruFit CB plug. The procedure is designed to be a single-stage, minimally invasive operation, which is a significant advantage over more complex, two-stage procedures like autologous chondrocyte implantation (ACI). The technique involves preparing the defect site to ensure a tight, press-fit of the plug. The plug is then implanted into the defect, where it encourages the formation of repair tissue that is not only histologically but also biomechanically superior to fibrocartilage. This is a crucial step towards achieving a more durable and robust repair, allowing patients to regain function and potentially delay or avoid the need for more extensive joint replacement surgeries.
A New Era for Cartilage Repair
The early clinical experiences with the TruFit CB plug are highly encouraging. The findings suggest that this new approach can lead to improved outcomes in cartilage repair, addressing some of the key limitations of previous techniques.
Professor Wilson’s Comments
“When the TruFit osteochondral plug (Smith & Nephew) was first introduced, the early reported results appeared extremely promising. Like many surgeons, I was initially enthusiastic about the potential of this technology and began to use it selectively — primarily as a salvage procedure in cases where the next step would have been a total or partial knee replacement. I made a conscious decision not to use it in younger patients, reserving it only for those where other options were limited.
However, despite the positive early reports, my own clinical outcomes were disappointing. I quickly became suspicious that the plug was not performing as effectively as advertised. While most studies at the time relied on clinical follow-up and MRI imaging, I believed these methods did not adequately assess bone integration or regeneration. To properly evaluate the biological performance, I undertook a study using CT scans — the first such study to assess TruFit plugs in this way.
The findings were deeply concerning. In one case, at six months post-implantation, I performed a follow-up arthroscopy and found only a thin superficial covering over the defect. When I probed the area, my arthroscopic instrument disappeared into a cavity, confirming a lack of underlying bone formation.
To objectively measure bone regeneration, I used Hounsfield Unit (HU) analysis, which quantifies bone density on CT scans. The results demonstrated extremely low HU values, indicating virtually no bone formation within the plug site across my series.
Recognising the significance of these findings, I felt a professional and ethical duty to present them — despite knowing they reflected poor outcomes. I delivered this data at the British Knee Society, highlighting the inadequate bone regeneration and potential risks of using the TruFit system. Although it was difficult to present such negative findings publicly, I believed it was vital for the wider surgical community to be aware.
Following my presentation, Smith & Nephew withdrew the TruFit plug from the global market. While it was challenging to report poor results, the impact was significant — likely preventing many future complications, especially in younger patients who might otherwise have been exposed to a failed technology.
In retrospect, this experience underscored the importance of rigorous evaluation, critical thinking, and the courage to report negative outcomes. It also highlighted the value of CT-based Hounsfield Unit analysis in accurately assessing bone quality and regeneration, rather than relying solely on clinical or MRI outcomes. This case serves as a powerful reminder that innovation in surgery must be accompanied by robust evidence and honest reflection.”
To get the full picture of the study’s data and methodology, we recommend consulting the complete research paper:
To get the full picture of the study’s data and methodology, we recommend consulting the complete research paper:
TruFit CB Bone Plug: Chondral Repair, Scaffold Design, Surgical Technique, and Early Experiences
Sources used in report overview:
- https://www.researchgate.net/publication/43344838_TruFit_CBR_bone_plug_Chondral_repair_scaffold_design_surgical_technique_and_early_experie
