Milgram Joshua, Hod Nitai, Benzioni Hadas
Department of Surgery, Veterinary Teaching Hospital, Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, Rehovot, Israel.
Vet Surg. 2012 Aug;41(6):671-6. doi: 10.1111/j.1532-950X.2012.01000.x. Epub 2012 Jul 23.
To determine if normograde and retrograde pinning of the distal humeral fragment, to maximize pin purchase in this fragment, would damage vital structures in and around the elbow and shoulder joints in dogs.
Anatomic study.
Cadaveric dogs (n = 12; 12 thoracic limb pairs).
Twelve thoracic limb pairs were harvested from cross-breed dogs and 1 thoracic limb from each pair was allocated to 1 of 3 groups. A transverse osteotomy was created at the junction of the middle and distal thirds in the diaphyseal fracture group (n = 8) and proximal to the supracondylar foramen in the metaphyseal fracture group (n = 8). The humeri in the normograde group (n = 8) were left intact. In all specimens in the distal and supracondylar fracture groups, retrograde pinning of the distal fragment was performed with the elbow flexed. The pins were driven into the medial epicondyle until they exited the skin caudal to the elbow. Dissection of the soft tissues around the exit tract of the pin was performed. The fracture was then reduced and the pin was advanced until it exited the proximal humeral fragment. In the specimens in the normograde group, pinning was initiated on the distal aspect of the medial epicondyle. The pin was directed parallel to the caudal aspect of the medial epicondyle and driven proximally into the humerus until it exited the proximal humerus.
Pins exiting the distal aspect of the medial epicondyle passed through muscle origins in 7 specimens in the diaphyseal osteotomy group and in all 8 specimens in the metaphyseal group. The ulnar nerve was entrapped in 1 specimen in the metaphyseal osteotomy group; however, it was not entrapped in any of the specimens in the diaphyseal osteotomy group. The articular cartilage of the trochlea was damaged in 2 specimens in each of the retrograde pinned groups. There was no damage to articular or periarticular structures by pins exiting the proximal humerus.
Retrograde pinning of the distal fragment in humeral fractures in the dog may damage the articular cartilage and cannot be recommended.
确定肱骨远端骨折块的顺行和逆行穿针固定，以最大限度地使针固定在该骨折块中，是否会损伤犬肘部和肩关节内及周围的重要结构。
解剖学研究。
尸体犬（n = 12；12对胸肢）。
从杂种犬身上获取12对胸肢，每对中的1个胸肢被分配到3组中的1组。在骨干骨折组（n = 8）中，于骨干中、远三分之一交界处制作横行截骨；在干骺端骨折组（n = 8）中，于髁上孔近端制作横行截骨。顺行组（n = 8）的肱骨保持完整。在远端和髁上骨折组的所有标本中，在肘关节屈曲的情况下对远端骨折块进行逆行穿针。将针打入内侧髁直至其从肘关节尾侧穿出皮肤。对针穿出通道周围的软组织进行解剖。然后复位骨折，并将针推进直至其穿出肱骨近端骨折块。在顺行组的标本中，从内侧髁远端开始穿针。针平行于内侧髁尾侧方向打入，并向近端打入肱骨直至其穿出近端肱骨。
骨干截骨组7个标本以及干骺端组所有8个标本中，从内侧髁远端穿出的针穿过了肌肉起点。在干骺端截骨组1个标本中尺神经被卡压；然而，骨干截骨组的任何标本中均未出现尺神经卡压。在每个逆行穿针组中，有2个标本的滑车关节软骨受损。从肱骨近端穿出的针未对关节或关节周围结构造成损伤。
犬肱骨骨折时对远端骨折块进行逆行穿针可能会损伤关节软骨，不建议采用。
