This animal study compares different methods
of performing an osteotomy, including using an Erbium-doped Yttrium
Aluminum Garnet laser, histologically, radiologically and biomechanically.
A total of 24 New Zealand rabbits were divided into four groups
(Group I: multihole-drilling; Group II: Gigli saw; Group III: electrical
saw blade and Group IV: laser). A proximal transverse diaphyseal
osteotomy was performed on the right tibias of the rabbits after the
application of a circular external fixator. The rabbits were killed
six weeks after the procedure, the operated tibias were resected
and radiographs taken. The specimens were tested biomechanically using three-point bending
forces, and four tibias from each group were examined histologically.
Outcome parameters were the biomechanical stability of the tibias
as assessed by the failure to load and radiographic and histological
examination of the osteotomy site. The osteotomies healed in all specimens both radiographically
and histologically. The differences in the mean radiographic (p
= 0.568) and histological (p = 0.71) scores, and in the mean failure
loads (p = 0.180) were not statistically significant between the
groups. Different methods of performing an osteotomy give similar quality
of union. The laser osteotomy, which is not widely used in orthopaedics
is an alternative to the current methods. Cite this article:
We compared time-dependent changes in the biomechanical properties of single-and double-row repair of a simulated acute tear of the rotator cuff in rabbits to determine the effect of the fixation techniques on the healing process. A tear of the supraspinatus tendon was created in 80 rabbits which were separated into two equal groups. A single-row repair with two suture anchors was conducted in group 1 and a double-row repair with four suture anchors in group 2. A total of ten intact contralateral shoulder joints was used as a control group. Biomechanical testing was performed immediately post-operatively and at four and eight weeks, and histological analysis at four and eight weeks. The mean load to failure in group 2 animals was greater than in group 1, but both groups remained lower than the control group at all intervals. Histological analysis showed similar healing properties at four and eight weeks in both groups, but a significantly larger number of healed tendon-bone interfaces were identified in group 2 than in group 1 at eight weeks (p <
0.012). The ultimate load to failure increased with the number of suture anchors used immediately post-operatively, and at four and eight weeks. The increased load to failure at eight weeks seemed to be related to the increase in the surface area of healed tendon-to-bone in the double-row repair group.
