Fink B, Braunstein S, Singer J, Schmielau G, Rüther W
Animal Clinic and the Institute for Pathology of the Heinrich-Heine-University of Düsseldorf, Germany.
J Pediatr Orthop. 1999 May-Jun;19(3):380-5.
Twenty-two dogs were provided with a circular fixator. Lengthening of the right lower leg by 2.5 cm was performed on 18 dogs 5 days after tibial osteotomy using a distraction rate of 0.5 mm, twice per day. Nine dogs with leg lengthening and two dogs of the control group without leg lengthening were sacrificed at the end of the distraction phase of 25 days and the remaining dogs after another 25 days. Post mortem, the tendons of the tibialis anterior, extensor digitorum longus, peroneus longus, and the Achilles tendon were taken from the operated-on right side and the left nonoperated-on control side and were analyzed histologically. The control group showed no histologic changes in the tendons of either side nor in those of the unlengthened left side of the operated-on dogs. Thirty-three tendons (41%) of dogs with leg lengthening were seen to have undergone histomorphological changes. An increase of the peritendinous connective tissue was seen, combined with chronic inflammatory cell infiltration in the tendons and/or the epitendinous tissues, edema, tendon fragmentation, necrosis, scarring of the tendons with dystrophic calcification and/or ossification, and broadening of the tenosynovial sheath. Furthermore, signs of histoneogenesis with growth in the tendons were found. Degenerative changes occurred far more often in the tendons of the ventral side of the lower leg and a slight pes equinus was regularly observed in the lengthened extremity. Therefore, pes equinus prevention and physiotherapy are important in the therapeutic use of lower-leg lengthening to minimize possible stress-induced damage of the ventral tendons.
给22只狗安装了环形固定器。在18只狗胫骨截骨术后5天，以每天2次、每次0.5毫米的牵张速率对右下肢进行2.5厘米的延长。在25天牵张期结束时，处死9只接受肢体延长的狗和2只未进行肢体延长的对照组狗，其余的狗在再过25天后处死。死后，从手术的右侧和未手术的左侧取出胫骨前肌、趾长伸肌、腓骨长肌肌腱以及跟腱，并进行组织学分析。对照组两侧的肌腱以及手术狗未延长的左侧肌腱均未显示组织学变化。接受肢体延长的狗中有33条肌腱（41%）出现了组织形态学变化。可见腱周结缔组织增多，同时伴有肌腱和/或腱外组织的慢性炎性细胞浸润、水肿、肌腱断裂、坏死、肌腱瘢痕形成伴营养不良性钙化和/或骨化，以及腱鞘增宽。此外，还发现了肌腱中有生长的组织形成迹象。退行性变化在小腿腹侧的肌腱中更为常见，并且在延长的肢体中经常观察到轻度马蹄足。因此，在小腿延长治疗中，预防马蹄足和物理治疗对于尽量减少腹侧肌腱可能的应力性损伤很重要。
