Department of Orthopedics, Detroit Receiving Hospital, Detroit, MI 48201, USA.
Injury. 2012 Jul;43(7):1176-81. doi: 10.1016/j.injury.2012.03.022. Epub 2012 Apr 26.
Leg length discrepancy (LLD) following intramedullary nailing of femoral fractures is not uncommon. We designed a prospective study to evaluate the efficacy of routine postoperative computed tomography (CT) scanograms for evaluation of limb length discrepancy in patients with comminuted Winquist III or IV femoral shaft fractures treated with intramedullary nailing.
The study consisted of 15 patients with Winquist III and 13 with a Winquist IV femoral shaft fracture pattern with an average age of 37 years. The mechanisms of injury were motor vehicle collision (13), gunshot wound (12) and falls (three). All patients were treated with a statically locked intramedullary femoral nail (18 antegrade and 10 retrograde). A CT scanogram evaluated limb length in all patients. A discrepancy of greater than 20mm was considered for correction during the same admission. An LLD of 15-20mm was discussed with the patient extensively for correction.
In the 28 patients included in our study, the average limb length discrepancy was 9.1mm with a range of -43.5mm short to 10.3mm long. The LLD was less than 10mm in 18 patients (64%), 10-15mm in four patients (14%), 15-20mm in three patients (11%) and more than 20mm in three patients (11%). Measurement of discrepancy as small as 0.5mm showed that 18 patients were fixed with shortening and in 10 patients the operated femur was longer. Tibia lengths were also evaluated separately. Though none of the tibiae had a previous fracture, only three patients (10%) had tibiae of equal length. In 13 patients, an unequal tibia partially corrected the LLD whilst in 12 it added to the discrepancy. Five patients with LLD of greater than 15mm underwent correction.
A postoperative scanogram in patients with comminuted femoral shaft fractures treated with intramedullary nailing is useful to evaluate LLD and allows for early intervention. The ideal length where correction is necessary remains unclear.
股骨干骨折髓内钉固定后出现肢体长度差异（LLD）并不少见。我们设计了一项前瞻性研究，以评估常规术后计算机断层扫描（CT）扫描对接受髓内钉治疗粉碎性 Winquist III 或 IV 股骨干骨折患者肢体长度差异的评估效果。
该研究包括 15 例 Winquist III 型和 13 例 Winquist IV 型股骨干骨折患者，平均年龄 37 岁。损伤机制为机动车碰撞（13 例）、枪伤（12 例）和跌倒（3 例）。所有患者均采用静态锁定髓内钉（18 例顺行和 10 例逆行）治疗。所有患者均行 CT 扫描评估肢体长度。在同一住院期间，将差值大于 20mm 的患者考虑进行矫正。与患者广泛讨论 15-20mm 的 LLD 是否需要矫正。
在我们纳入的 28 例患者中，平均肢体长度差异为 9.1mm，范围为-43.5mm 短至 10.3mm 长。18 例患者（64%）的 LLD 小于 10mm，4 例患者（14%）的 LLD 为 10-15mm，3 例患者（11%）的 LLD 为 15-20mm，3 例患者（11%）的 LLD 大于 20mm。即使测量差异小至 0.5mm，也有 18 例患者固定后出现缩短，而 10 例患者患肢较长。还分别评估了胫骨长度。尽管没有患者之前有过骨折，但只有 3 例患者（10%）的胫骨等长。在 13 例患者中，不等长的胫骨部分矫正了 LLD，而在 12 例患者中则增加了差异。5 例 LLD 大于 15mm 的患者接受了矫正。
股骨干骨折髓内钉固定术后的扫描有助于评估 LLD，并允许早期干预。仍不清楚需要矫正的理想长度。
