SLR - June 2012 - Terence Vincent
Reference: Connell, D. et. al. (2012). Skin-Derived Fibroblasts for the Treatment of Refractory Achilles Tendinosis: Preliminary Short-Term Results. The Journal of Bone and Joint Surgery, 94-A, 193-200
Scientific Literature Review
Reviewed by: Terence Vincent, DPM
Residency Program: OCPM & University Hospital Richmond Heights Medical Center
Podiatric Relevance:
This prospective study offers insight into the use of an autologous skin-derived fibroblast injection as a possible treatment for refractory Achilles tendinosis. This recent treatment modality continues to be studied with some promise for use as an alternative to failed traditional conservative treatments.
Methods:
A randomized, double blind study was performed with a sample group of 32 patients with 40 Achilles tendons with a mean age of 45.2 and followed for a total of six months. Twenty-four of the patients with unilateral tendinosis were computer randomized into equal numbers of two groups of 12 tendons for treatment and control. This same randomization was then performed with the patients with bilateral tendinosis into two equal groups of eight tendons for control and treatment. Treatment groups received ultrasound-guided, laboratory-processed, skin-derived fibroblasts suspended in autologous plasma (skin sample from the patient’s thigh) and control injected with local anesthetic with physical therapy. Prior to injection, all patients received six months of standardized eccentric based physical therapy, and if the patient improved significantly as according to the visual analog scale (VAS) and Victorian Institute of Sport Assessment (VISA), they were excluded. Those without improvement continued in the study. Patients’ VAS and VISA scores and ultrasound assessment were taken at different periods throughout the study ending at the patients’ six month follow-up. Statistical analysis was then performed on the VAS and VISA scores of the bilateral and unilateral groups separately.
Results:
The VISA and VAS scores were analyzed by Mann-Whitney U test, and demonstrated significant improvement in the unilateral treatment group and failed to show significance in the bilateral group, except the six month VAS score with p= 0.038 (VISA score measuring subjective and objective functional status and VAS measuring the level of health). In the unilateral group, significance in the VISA score was seen at the second visit, three month and six month follow up from 35.00 to 79.50 with a p value of <0.001 at six months. VAS scores showed significance at the second visit and six months, with a decrease at six months at 3.00 to 1.00 with a p value of p<0.001.
Conclusions:
The preliminary results of this study show some promise but need more research with a larger sample group. The bilateral group was studied separate as to avoid systemic effects. Bilateral patients had no significance possibly due the small sample and patients having difficulty differentiating each side for improvement. The unilateral group is noted to have possibly difference in the functional group due to the sensitivity of physical therapy pretreatment.
However, the laboratory technique and processing of the skin derived fibroblast still remains a tedious process and patients are subjected to a thigh punch biopsy for the initial skin sample. It is the believed that the collagen producing cells would provide a matrix for repair at tendinous injury; however, there has not been an established standardization of the amount of the fibroblast injection that is needed to heal pathological tendon. Furthermore, the study was weakened with no histopathology studies of tendon subjected to the treatment. Overall the patients had improvements in their symptoms and the treatment proved safe for use, but obviously there needs to be further studies.