An evaluation of two autologous tendon grafting techniques in ponies.

This research investigates the healing and strength differences between two types of autologous tendon grafting techniques in ponies. The two methodologies, using a multiple split tendon graft and a whole tendon graft, resulted in no significant differences with respect to healing speed or sustainability.

Study Design and Methodology

The experiment used six mixed-gender ponies of varying ages. Tenotomies were conducted in the forelimb’s deep digital flexor tendons (DDFT), strategically distal to the point where the accessory ligament is inserted (AL-DDFT).

• Free autologous grafts, taken from the hindlimb lateral digital extensor tendon (LDET), were used to repair the DIGITS.
• These infrapatellar tendons were either left whole (Whole Graft-WG) or split into three longitudinal portions (Multiple Graft-MG).
• The tendons and graft sites were then collected and subjected to a load (2.54 cm/s) until failure point, either 4 or 8 weeks after the surgery.
• The cross-sectional area of the tendons was determined using two methods: an Impression Cast (IC) and an Inkblot (IB) measurement.
• Tissue maturity and inflammation levels were analyzed under a microscope.

Findings

Gap formation was observed consistently across all repair sites, regardless of whether the graft was a MG or WG. In terms of healing or mechanical strength, no statistical difference was identified between the two graft methods.

• The strength of the 8-week-old repairs was found to be significantly greater (p<0.0005) compared to those of 4 weeks.
• Microscopic assessment showed more matured tissue at the 8th week as compared to the 4th, but no significant differences in inflammatory responses across the two time points were noted.

Conclusions

In conclusion, due to these findings, it appears that both the multiple split and whole autologous tendon grafting approaches contribute to a successful early recovery in ponies. Yet, splitting the tendon graft does not seem to give any significant advantage over using a whole graft in terms of either healing speed or ultimate strength.