(i) Novel treatments for early osteoarthritis of the knee

Impact-induced cartilage damage assessed using polarisation-sensitive optical coherence tomography

Non-invasive determination of structural changes in articular cartilage immediately after impact and rehydration provides insight into the response and recovery of the soft tissue, as well as provides a potential methodology for clinicians to quantify early degenerative changes. In this study, we use polarisation-sensitive optical coherence tomography (PS-OCT) to examine subtle alterations of the optical properties in healthy and early-stage degenerate articular cartilage immediately after impact loading to identify structurally relevant metrics required for understanding the mechanical factors of osteoarthritic initiation and progression. A custom-designed impact testing rig was used to deliver 0.9 J and 1.4 J impact energies to bovine articular cartilage. A total of 52 (n=26 healthy, n=26 mildly degenerate) cartilage-on-bone samples were imaged before, immediately after, and 3 h after impact. PS-OCT images were analyzed to assess changes relating to surface irregularity, optical attenuation, and birefringence. Mildly degenerate cartilage exhibits a significant change in birefringence following 1.4 J impact energies compared to healthy samples which is believed to be attributable to degenerate cartilage being unable to fully utilise the fluid phase to distribute and dampen the energy. After rehydration, the polarisation-sensitive images appear to 'optically-recover' reducing the reliability of birefringence as an absolute metric. Surface irregularity and optical attenuation encode diagnostically relevant information and may serve as markers to predict the mechanical response of articular cartilage. PS-OCT with its ability to non-invasively image the sub-surface microstructural abnormalities of cartilage presents as an ideal modality for cartilage degeneration assessment and identification of mechanically vulnerable tissue.

Arthroscopic debridement of unicompartmental arthritis: fact or fiction?

Patients with recurrent or mechanical symptoms of unicompartmental knee arthritis that have failed conservative management are candidates for surgical intervention. Surgical options include debridement, lavage, chondroplasty, bone marrow-stimulating techniques, chondrocyte transfer, and chondrocyte implantation. These techniques have been well studied but it is still unclear which technique is superior. Various factors need to be accounted for when choosing the proper technique; among the factors discussed are the patient's age and the size of the articular cartilage defect.

Orthopedic surgeons feel that there is a treatment gap in management of early OA: international survey

PURPOSE

To understand orthopedic surgeons' views, preferences, and awareness on "treatment gap" and various conservative and surgical treatments for early to mid-stage knee osteoarthritis (OA).

METHODS

A self-administered questionnaire on the treatment of knee OA was developed in collaboration with orthopedic surgeons with extensive research experience and methodological expertise. The survey was distributed electronically to a group of international orthopedic surgeons and surgical trainees. The data were collected, reviewed, and analyzed using descriptive statistics.

RESULTS

One hundred and seventy-three surgeons and surgical trainees completed the survey. The respondents reported that about 58 % of the patients they treat have early to mid-stage knee OA (Kellgren and Lawrence grade I-III). There were significantly higher usage of medications and lower usage of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) (P < 0.05) in developing countries than in developed countries. Four of five surgeons (84 %) perceived a need for better treatments for younger (<60 years old) physically active OA patients in which UKA or TKA is not indicated. Most respondents (80 %) would be willing to adjust age/activity threshold for surgery if a procedure was reversible and recovery was minimal. Two of three surgeons (68.4 %) perceived a treatment gap for early knee OA. However, effective treatments for patients within the treatment gap would have substantial positive social, and economic impacts.

CONCLUSION

The study suggests an ongoing treatment gap for patients with early knee OA and the need for better evidence to guide practice.

Chondroitin sulfate in osteoarthritis therapy

Despite the news of aid from chondroitin sulfate, recent research has questioned its efficacy in treating osteoarthritis.

Isolated patellofemoral osteoarthritis

Isolated patellofemoral osteoarthritis is now recognised to be more common than previously thought. The features and management are reviewed, including the various surgical options in symptomatic patients. The evidence base for managing patellofemoral osteoarthritis is behind that for the tibiofemoral joint. All treatments are based on uncontrolled observational case series, typically retrospectively reviewed. Fortunately the majority of patients with isolated patellofemoral degenerative changes do not need surgical treatment. Those who are symptomatic can usually be successfully treated with weight loss and quadriceps strengthening exercises.

Novel hydroxyapatite/chitosan bilayered scaffold for osteochondral tissue-engineering applications: Scaffold design and its performance when seeded with goat bone marrow stromal cells

Recent studies suggest that bone marrow stromal cells are a potential source of osteoblasts and chondrocytes and can be used to regenerate damaged tissues using a tissue-engineering (TE) approach. However, these strategies require the use of an appropriate scaffold architecture that can support the formation de novo of either bone and cartilage tissue, or both, as in the case of osteochondral defects. The later has been attracting a great deal of attention since it is considered a difficult goal to achieve. This work consisted on developing novel hydroxyapatite/chitosan (HA/CS) bilayered scaffold by combining a sintering and a freeze-drying technique, and aims to show the potential of such type of scaffolds for being used in TE of osteochondral defects. The developed HA/CS bilayered scaffolds were characterized by Fourier transform infra-red spectroscopy, X-ray diffraction analysis, micro-computed tomography, and scanning electron microscopy (SEM). Additionally, the mechanical properties of HA/CS bilayered scaffolds were assessed under compression. In vitro tests were also carried out, in order to study the water-uptake and weight loss profile of the HA/CS bilayered scaffolds. This was done by means of soaking the scaffolds into a phosphate buffered saline for 1 up to 30 days. The intrinsic cytotoxicity of the HA scaffolds and HA/CS bilayered scaffolds extract fluids was investigated by carrying out a cellular viability assay (MTS test) using Mouse fibroblastic-like cells. Results have shown that materials do not exert any cytotoxic effect. Complementarily, in vitro (phase I) cell culture studies were carried out to evaluate the capacity of HA and CS layers to separately, support the growth and differentiation of goat marrow stromal cells (GBMCs) into osteoblasts and chondrocytes, respectively. Cell adhesion and morphology were analysed by SEM while the cell viability and proliferation were assessed by MTS test and DNA quantification. The chondrogenic differentiation of GBMCs was evaluated measuring the glucosaminoglycans synthesis. Data showed that GBMCs were able to adhere, proliferate and osteogenic differentiation was evaluated by alkaline phosphatase activity and immunocytochemistry assays after 14 days in osteogenic medium and into chondrocytes after 21 days in culture with chondrogenic medium. The obtained results concerning the physicochemical and biological properties of the developed HA/CS bilayered scaffolds, show that these constructs exhibit great potential for their use in TE strategies leading to the formation of adequate tissue substitutes for the regeneration of osteochondral defects.