This review provides a concise outline of the advances made in the care of patients and to the quality of life after a traumatic spinal cord injury (SCI) over the last century. Despite these improvements reversal of the neurological injury is not yet possible. Instead, current treatment is limited to providing symptomatic relief, avoiding secondary insults and preventing additional sequelae. However, with an ever-advancing technology and deeper understanding of the damaged spinal cord, this appears increasingly conceivable. A brief synopsis of the most prominent challenges facing both clinicians and research scientists in developing functional treatments for a progressively complex injury are presented. Moreover, the multiple mechanisms by which damage propagates many months after the original injury requires a multifaceted approach to ameliorate the human spinal cord. We discuss potential methods to protect the spinal cord from damage, and to manipulate the inherent inhibition of the spinal cord to regeneration and repair. Although acute and chronic SCI share common final pathways resulting in cell death and neurological deficits, the underlying putative mechanisms of chronic SCI and the treatments are not covered in this review.

Introduction and Aims: Large or recurrent rotator cuff tendon tears are difficult to treat effectively. Collagen bio-scaffolds have become available to reinforce a tendon repair or as an interpositional graft. This study compares the suitability of two collagen bio-scaffolds for autologous tenocyte implantation, and assesses the in vivo rotator cuff healing response with these grafts in a rabbit model. Method: Tenocytes were isolated from rabbit tendon, cultured and seeded onto the Restore patch (DePuy), or the Matricel (Verigen) collagen membrane. Serial scanning electron microscopy examined tenocyte integration with the bio-scaffold, and extra-cellular matrix synthesis over time. A rotator cuff tendon defect was created in 50 rabbits and repaired by either: a) direct suture to tuberosity; b) Matricel interposition graft; c) Matricel interposition with autologous tenocytes; d) Restore patch interposition graft; e) Restore patch interposition with autologous tenocytes. Gross and histological evaluation were performed at four weeks and eight weeks post-surgery. Results: Scanning electron microscopy of the Matricel membrane showed a rough surface characterised by a loose arrangement of collagen fibres capable of cell adhesion. SEM at one, three and five days after cell seeding, showed progressive integration of tenocytes into the three-dimensional membrane structure with extra-cellular matrix neosynthesis in the spaces between the native collagen fibres. SEM of the Restore patch showed a relatively smooth surface of highly compacted collagen fibres. Serial SEM after cell seeding showed relatively less tenocyte integration onto the membrane surface though tenocyte replication and matrix neo-synthesis was observed. All 50 rabbits regained normal gait at two weeks post-surgery. At sacrifice, no tendon ruptures had occurred at either time point in any of the five groups. At four weeks, the Matricel and Restore bio-scaffold membranes were partially absorbed, and a florid lymphocytic inflammatory response was evident surrounding the remaining membrane. By eight weeks, graft tissue had been resorbed further, the inflammatory response had decreased, and the regenerating tendon showed progressive remodelling. Autologous tenocyte implantation on both membranes improved the reparative tendon histological grade at eight weeks compared to membranes without cell implantation, and was equivalent to the direct repair group. Conclusion: Autologous tenocytes can be implanted onto both Matricel and Restore collagen bio-scaffolds. Though both Xeno grafts induce an anti-inflammatory response in vivo, membrane resorption subsequently occurs. The healing response of large rotator cuff defects treated with interpositional collagen grafts is improved with autologous tenocyte implantation in a rabbit model

Injury to the anterior cruciate ligament (ACL) is one of the most devastating and frequent injuries of the knee. Surgical reconstruction is the current standard of care for treatment of ACL injuries in active patients. The widespread adoption of ACL reconstruction over primary repair was based on early perception of the limited healing capacity of the ACL. Although the majority of ACL reconstruction surgeries successfully restore gross joint stability, post-traumatic osteoarthritis is commonplace following these injuries, even with ACL reconstruction. The development of new techniques to limit the long-term clinical sequelae associated with ACL reconstruction has been the main focus of research over the past decades. The improved knowledge of healing, along with recent advances in tissue engineering and regenerative medicine, has resulted in the discovery of novel biologically augmented ACL-repair techniques that have satisfactory outcomes in preclinical studies. This instructional review provides a summary of the latest advances made in ACL repair.

Cite this article: Bone Joint Res 2014;3:20–31.