Fig. 7-A Fig. 7-B Fig. 7-C.

Fig. 7-A Tartrate-resistant acid phosphatase (TRAP) staining for osteoclasts on an axial section of the tibial tunnel from an animal treated with immediate loading and killed at four weeks (×40). Fig. 7-B Tartrate-resistant acid phosphatase staining for osteoclasts on an axial section of the tibial tunnel from an animal treated with delayed loading starting on postoperative day 4 and killed at four weeks (×40). Note the substantially reduced number of osteoclasts at the tendon-bone interface in the specimen from the delayed-loading group compared with that from the immediate-loading group. Fig. 7-C Significantly fewer osteoclasts were observed at the tendon-bone interface in both delayed-loading groups compared with the number in the immediate-loading or immobilization group at two and four weeks postoperatively (p < 0.01). HPF = high-power field.