Introduction Determining the extent of dynamic creep of a suture gives insight into the potential for formation of a flexor tendon repair site gap, with less creep having a positive benefit. We wanted to determine the dynamic creep of various suture materials using a cyclical testing protocol that simulates 30 days of active mobilisation.

Methods Four-strand loops, 20 mm in length, were created using Prolene, Ticron, Ethibond, and Mersilene (n=8 per group). Samples were loaded between 3.5N and 35N at 10 cycles per minute for 3000 cycles using a materials testing machine. All testing was conducted in phosphate buffered saline at 37° celsius. The dynamic creep was determined for each group. A separate group of suture loops were also created for load to failure testing. All data was analysed using ANOVA on SPSS software.

Results The loads to failure were 55.4, 65.5, 64.4 and 73.1N for Prolene, Ticron, Ethibond and Mersilene respectively. During cyclical testing, only one Prolene sample survived, with failure occurring after a mean of 1182 cycles (range 574 to 2660). Of those that failed, the mean creep was 3.80 mm (SD=0.51). In contrast, no specimens in the other groups failed, with a dynamic creep of 0.44 mm (SD=0.19), 0.32 mm (SD=0.17), and 0.28 mm (SD=0.07) for Ticron, Ethibond and Mersilene respectively.

Conclusions Regardless of your chosen suture technique for flexor tendon repairs, this study suggests that the suture material itself can play an important role in the eventual outcome. These results should be kept in mind when deciding on the suture material for your repairs.

Introduction: The realisation that the medical and lateral menisci of the knee have important load-bearing and stability functions has stimulated orthopaedic surgeons to aim for preservation rather than excision if at all possible. The absence of meniscal tissue has been shown to increase load through the articular cartilage and ultimately accelerate the process of osteoarthritic degeneration. A major limitation is the relative avascularity of a large portion of the normal meniscus. McAndrews and Arnoczky reported in 1996 that repair of the white-white and even red-white zone remains a challenge. Monobutyrin is an angiogenic factor that has been used in the stimulation of healing burns and we hypothesized that it may have a positive effect on the healing meniscus.

The aim of the study was to determine the effects of 0 Ticron suture soaked in polyhydroxybutyrate (PHB) on the histological and mechanical properties of healing meniscal tears in the red-white zone in an established animal model.

Methods: A bilateral medical meniscal incision model was used in 21 adult sheep.

Results: We confirmed that the PHB had no deleterious effects on the mechanical properties of the suture prior to commencing the surgery. Mechanical testing of the menisci at the set time-points demonstrated a significantly stronger repair in the PHB-soaked group. Macroscopic appearances were graded and found to be improved with PHB soaked sutures. On histological examination there were features suggestive of a more intense healing response including angiogenesis.

Conclusions: We have concluded that the use of butyric acid has no deleterious effects on the mechanical properties of the suture used and has positive effects on meniscal healing. We recommend further examination of this exciting development.