III.

We sought to determine whether smoking affected the outcome of reconstruction of the anterior cruciate ligament. We analysed the results of 66 smokers (group 1 with a mean follow-up of 5.67 years (1.1 to 12.7)) and 238 non-smokers (group 2 with a mean follow-up of 6.61 years (1.2 to 11.5)), who were statistically similar in age, gender, graft type, fixation and associated meniscal and chondral pathology. The assessment was performed using the International Knee Documentation Committee form and serial cruciometer readings. Poor outcomes were reported in group 1 for the mean subjective International Knee Documentation Committee score (p < 0.001), the frequency (p = 0.005) and intensity (p = 0.005) of pain, a side-to-side difference in knee laxity (p = 0.001) and the use of a four-strand hamstring graft (p = 0.015). Patients in group 1 were also less likely to return to their original level of pre-injury sport (p = 0.003) and had an overall worse final 7 International Knee Documentation Committee grade score (p = 0.007). Despite the well-known negative effects of smoking on tissue healing, the association with an inferior outcome after reconstruction of the anterior cruciate ligament has not previously been described and should be included in the pre-operative counselling of patients undergoing the procedure.

The Achillon repair appears to be a biomechanically sound method of repair for the acutely ruptured Achilles tendon.

Compression staples are a popular form of fixation for osteotomy and arthrodesis. "Mechanical compression" or "shape memory" designs are commercially available. We performed a biomechanical study comparing these designs. A load cell measured compression across a simulated fusion site. The two designs available were tested and compared. The effect of altering staple limb length was also assessed. The limbs of all mechanical compression staples diverged causing inconsistent compression and distraction. Shape memory staples all achieved consistent compression across the fusion site with significantly greater maximum force when compared to mechanical compression staples (P < 0.001). Staple limb length did not appear to alter compression force generated. Mechanical compression staples cause a distractive force, and we therefore suggest alternate forms of fixation for arthrodesis. Shape memory staples do provide compression and may be suitable for arthrodesis and osteotomy.