Murphy Joshua S, Koehler Ryan, Johnson Megan, Hosseinzadeh Pooya
Children's Healthcare of Atlanta, Atlanta, Georgia.
Vanderbilt University, Nashville, Tennessee.
JBJS Essent Surg Tech. 2021 Mar 2;11(1). doi: 10.2106/JBJS.ST.19.00064. eCollection 2021 Jan-Mar.
Flexible intramedullary nailing is performed for femoral fractures in pediatric patients who may be too large for spica cast immobilization but who have substantial growth remaining and who are not a candidate for rigid intramedullary nailing. Flexible nailing allows the surgeon to obtain correct alignment of the femur fracture so as to allow for healing without a lower extremity deformity.
The patient is positioned on a radiolucent table, flexible nails are chosen according to the diameter of the medullary canal, medial and lateral incisions are made along the distal aspect of the thigh, and access to the canal is obtained with use of a drill-bit of the appropriate size. Flexible nails are contoured to place the apex at the location of the fracture site and then passed 1 at a time up to the fracture through the medial and lateral corticotomies. Fracture reduction is obtained, and the nails are passed across the fracture 1 at a time. Leave a small amount of nail prominent at the entry site; the nails are then cut and advanced with a tamp.
Spica cast immobilization, rigid intramedullary nailing, external fixation, and submuscular plating.
Flexible nailing provides relative stability of a femoral fracture similar to external fixation, submuscular plating, and rigid nailing; however, external fixators come with pin-track complications and infections, as well as a bulky device external to the thigh. Submuscular plating is beneficial for length-unstable fractures but is a longer procedure and implant removal is more difficult. In an older child with growth remaining, a rigid femoral nail is an option with similar outcomes to flexible nailing; however, the implant is harder to remove. Flexible nailing provides a cosmetic incision with reliable relative fixation in length-stable fractures, and easy removal of implants with equal or even improved outcomes compared with other surgical techniques.
The outcomes of this procedure are excellent. Most pediatric femoral fractures treated with flexible nailing heal well with few complications. Angulation at the fracture site is the most common complication and is more common in fractures of the proximal or distal third of the femur. Worse outcomes occur in older children and children who are heavier. Outcomes are improved when flexible nailing is done in length-stable fractures; however, postoperative immobilization in a single-leg spica cast or knee immobilizer can augment fixation in fractures that are not stable. Implant irritation can occur at the insertion site; however, the implants are easy to remove once the fracture has healed. There is a substantially lower rate of malunion when stainless-steel nails (6%) are utilized compared with titanium nails (23%). Consideration should therefore be given to the use of stainless-steel nails for pediatric femoral fractures.
Use a radiolucent table with either a post or a sheet for counter-traction aids during reductionUse stainless-steel nailsPass the easier nail firstAdvance into the femoral neck or trochanteric apophysisDo not wrap rods around each otherCut off the machined tip of the nail and custom-contour the nail in patients with poor bone quality.
对于因体型过大而不适用于髋人字石膏固定,但仍有大量生长潜力且不适合刚性髓内钉固定的小儿股骨骨折患者,可采用弹性髓内钉固定。弹性髓内钉固定可使外科医生实现股骨骨折的正确对线,从而促进骨折愈合且不导致下肢畸形。
患者置于可透X线的手术台上,根据髓腔直径选择弹性髓内钉,在大腿远端内侧和外侧做切口,使用合适尺寸的钻头进入髓腔。将弹性髓内钉塑形,使钉尖位于骨折部位,然后通过内侧和外侧皮质切开术每次1根地将髓内钉插入至骨折处。进行骨折复位,然后每次1根地将髓内钉穿过骨折部位。在入钉点处留一小段髓内钉外露;然后将髓内钉切断并用压棒推进。
髋人字石膏固定、刚性髓内钉固定、外固定和肌下钢板固定。
弹性髓内钉固定可为股骨骨折提供与外固定、肌下钢板固定和刚性髓内钉固定类似的相对稳定性;然而,外固定架存在针道并发症和感染风险,且大腿外部装置笨重。肌下钢板固定对长度不稳定骨折有益,但手术时间较长且取出植入物更困难。对于仍有生长潜力的大龄儿童,刚性股骨钉是一种选择,其效果与弹性髓内钉固定相似;然而,植入物更难取出。弹性髓内钉固定可提供美观的切口,对长度稳定的骨折有可靠的相对固定作用,与其他手术技术相比,植入物易于取出且效果相同甚至更好。
该手术效果极佳。大多数采用弹性髓内钉固定治疗的小儿股骨骨折愈合良好,并发症较少。骨折部位成角是最常见的并发症,在股骨近端或远端三分之一骨折中更常见。大龄儿童和体重较重的儿童预后较差。在长度稳定的骨折中采用弹性髓内钉固定,预后会得到改善;然而,术后使用单腿髋人字石膏或膝关节固定器可增强不稳定骨折的固定效果。植入物插入部位可能出现刺激;然而,骨折愈合后植入物易于取出。与钛钉(23%)相比,使用不锈钢钉(6%)时骨折不愈合率显著更低。因此,对于小儿股骨骨折应考虑使用不锈钢钉。
在复位过程中使用带有立柱或床单的可透X线手术台以辅助对抗牵引使用不锈钢钉先插入较易插入的髓内钉推进至股骨颈或大转子骨骺不要让髓内钉相互缠绕对于骨质较差的患者,切除髓内钉的加工尖端并进行定制塑形。