In the article by Klein et al entitled “Flexor Tendon Wound Healing In Vitro: The Effect of Lactate on Tendon Cell Proliferation and Collagen Production,” which appeared in the September 2001 issue (Vol 26A, No 5, pp 847–854), an error in calculation was made. On page 851, the sentence beginning on the last line of the first column should read: “Collagen type I production increased more than 37% by tendon sheath cells compared with baseline levels.” The data in Figure 4 is correct as it appears.