Investigating the histological and structural properties of tendon gel as an artificial biomaterial using the film model method in rabbits

Purpose This study aimed to evaluate the properties of tendon gel by investigating the histological and structural differences among tendon gels under different preservation periods using a rabbit model. Methods Forty mature female rabbits were divided into four groups, each containing ten rabbits, on the basis of in-vivo preservation periods of tendon gels (3, 5, 10, and 15 days). We created the Achilles tendon rupture models using the film model method to obtain tendon gels. Tensile stress was applied to the tendon gel to promote maturation. Histological and structural evaluations of the tendon gel were performed before and after applying the tensile force, and the results obtained from the four groups were compared. Results Although the day-3 and day-5 tendon gels before applying tensile stress were histologically more immature than the day-10 and day-15 gels, type I collagen fibers equivalent to those of normal tendons were observed in all groups after the tensile process. Based on the surface and molecular structural evaluations, the day-3 tendon gels after the tensile process were molecularly cross-linked, and thick collagen fibers similar to those present in normal tendons were observed. Structural maturation observed in the day-3 tendon gels caused by traction was hardly observed in the day-5, -10, and -15 tendon gels. Conclusions The day-3 tendon gel had the highest regenerative potential to become a normal tendon by applying a traction force.

Muscular and Tendon Degeneration after Achilles Rupture: New Insights into Future Repair Strategies

Achilles tendon rupture is a frequent injury with an increasing incidence. After clinical surgical repair, aimed at suturing the tendon stumps back into their original position, the repaired Achilles tendon is often plastically deformed and mechanically less strong than the pre-injured tissue, with muscle fatty degeneration contributing to function loss. Despite clinical outcomes, pre-clinical research has mainly focused on tendon structural repair, with a lack of knowledge regarding injury progression from tendon to muscle and its consequences on muscle degenerative/regenerative processes and function. Here, we characterize the morphological changes in the tendon, the myotendinous junction and muscle belly in a mouse model of Achilles tendon complete rupture, finding cellular and fatty infiltration, fibrotic tissue accumulation, muscle stem cell decline and collagen fiber disorganization. We use novel imaging technologies to accurately relate structural alterations in tendon fibers to pathological changes, which further explain the loss of muscle mechanical function after tendon rupture. The treatment of tendon injuries remains a challenge for orthopedics. Thus, the main goal of this study is to bridge the gap between clinicians’ knowledge and research to address the underlying pathophysiology of ruptured Achilles tendon and its consequences in the gastrocnemius. Such studies are necessary if current practices in regenerative medicine for Achilles tendon ruptures are to be improved.

Management of Missed Traumatic Achilles Tendon Rupture in a Pediatric Patient: A Case Report

BACKGROUND: Missed traumatic Achilles tendon ruptures in children are rarely reported in the literature. Various techniques have been described to reconstruct delayed Achilles tendon ruptures for adults, but the long-term consequences in the growing child are unknown. CLINICAL CASE: The article presents a clinical observation of a 8-year-old girl with missed rupture of the Achilles tendon operated 7 weeks after the trauma by end-to-end Kessler-type sutures augmented with the plantaris tendon. At 2-year follow-up, the patient was completely asymptomatic. DISCUSSION: A review of the literature shows that this is the third neglected pediatric case of post-traumatic Achilles tendon rupture. The first case concerns a 10-year-old boy treated successfully six weeks after the traumat by open surgical repair using the Bunnell sutures technique. The second patient was a 7-year-old girl, she was operated 8 weeks after the trauma with a termino-terminal tenorrhaphy using the Bunnell technique augmented with the plantaris tendon. CONCLUSIONS: Using the plantaris tendon to reinforce the Achilles tendon repair offers satisfactory results with minimal morbidity. Prognosis depends on the extent of tendon defect which determines the long-term functional outcome. Any skin wound that sits on the back of the leg requires a systematic and careful physical examination to check the integrity of the Achilles tendon.

Case report: Favorable outcomes of spinal cord stimulation in complex regional pain syndrome Type II consistent with thermography findings

Background: Complex regional pain syndrome (CRPS) is a chronic pain disorder that develops as a consequence of trauma to one or more limbs. Despite the availability of multiple modalities to diagnose CRPS, a gold standard technique for definitive diagnosis is lacking. Moreover, there are limited reports describing the use of spinal cord stimulation (SCS) to treat CRPS Type II, given the low prevalence of this condition. Herein, we present the case of a patient with CRPS Type II with novel thermography findings who underwent SCS for pain management after an Achilles tendon repair surgery. Case Description: A 38-year-old woman was referred to our institute because of chronic left leg pain after Achilles tendon rupture repair surgery. Her case was diagnosed as CRPS Type II based on the International Association for the Study of Pain diagnostic criteria. After an epidural block, thermography showed a significant increase in the body surface temperature of the foot on the observed side. She was subsequently treated with SCS, following which her pain ameliorated. She reported no pain flare-ups or new neurological deficits over 2 years of postoperative follow-up assessments. Conclusion: SCS could be a useful surgical treatment for medication refractory CRPS Type II as supported by our thermography findings. We may refine surgical indication for permanent implantation of SCS with the presented method.