Yilmaz Guney, Oto Murat, Thabet Ahmed M, Rogers Kenneth J, Anticevic Darko, Thacker Mihir M, Mackenzie William G
*Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE †Benha Medical School, Benha, Egypt ‡Department of Orthopaedic Surgery, Clinical Hospital Centre Zagreb, School of Medicine, University of Zagreb, Zagreb, Croatia.
J Pediatr Orthop. 2014 Apr-May;34(3):336-45. doi: 10.1097/BPO.0000000000000089.
Lower extremity angular deformities are common in children with skeletal dysplasia and can be treated with various surgical options. Both acute correction by osteotomy with internal fixation and gradual correction by external fixation have been used with acceptable results. Recently, the Guided Growth concept using temporary hemiepiphysiodesis for correction of angular deformities in the growing child has been proposed. This study presents the results of temporary hemiepiphysiodesis using eight-Plates and medial malleolus transphyseal screws in children with skeletal dysplasia with lower extremity angular deformities.
Twenty-nine patients (50 lower extremities) with skeletal dysplasia of different types were treated for varus or valgus deformities at 2 centers. The mean age at the time of hemiepiphysiodesis was 10±2.9 years. A total of 66 eight-Plates and 12 medial malleolus screws were used. The average follow-up time between the index surgery and the latest follow-up with the eight-Plate in was 25±13.4 months. Erect long-standing anteroposterior and lateral view radiographs were obtained for deformity planning before the procedure. Angular deformities on radiograph were evaluated by mechanical axis deviation, mechanical lateral distal femoral angle, medial proximal tibial angle, and lateral distal tibial angle. Mechanical axis deviation was also expressed as a percentage to one half of the width of the tibial plateau, and the magnitude of the deformity was classified by determining the zones through which the mechanical axis of the lower extremity passed. Four zones were determined on both the medial and lateral side of the knee and the zones were labeled 1, 2, 3, and 4, corresponding to the severity of the deformity. A positive value was assigned for valgus alignment and a negative for varus alignment.
Patients were analyzed in valgus and varus groups. There was correction in 34 of 38 valgus legs and 7 of 12 varus legs. In the valgus group, the mean preoperative and postoperative mechanical lateral distal femoral angles were 82.1±3.7 and 91.1±4.9 degrees, respectively (P<0.001). The mean preoperative and postoperative medial proximal tibial angles were 98.5±8 and 87.8±7.1 degrees, respectively (P<0.001). Six patients with bilateral ankle valgus deformities (12 ankles) underwent single-screw medial malleolus hemiepiphysiodesis. The mean preoperative and postoperative lateral distal tibial angles were 73.9±8.7 and 86.1±6.8 degrees, respectively (P<0.001). The numbers of plates in each anatomic location were not enough to make statistical conclusions in varus legs. Four patients in the valgus group and 3 patients in the varus group did not benefit from the procedure. Mechanical axes were in zone 2 or over in 94% of the legs preoperatively, whereas postoperatively, only 23% of the legs had mechanical axes in zone 2 or over in varus and valgus groups.
Growth modulation with an eight-Plate is a relatively simple surgery and has low risk of mechanical failure or physeal damage. It can be performed in very young patients, which is an important advantage in skeletal dysplasia. Screw purchase is reliable even in the abnormal epiphysis and metaphysis. Our results show that Guided Growth using eight-Plates in skeletal dysplasia is safe and effective.
Level IV.
下肢角畸形在骨骼发育不良的儿童中很常见，可通过多种手术方式治疗。采用截骨内固定进行急性矫正和采用外固定进行逐步矫正均已取得可接受的效果。最近，有人提出了使用临时半骨骺阻滞术来矫正生长中儿童角畸形的引导生长概念。本研究介绍了在患有下肢角畸形的骨骼发育不良儿童中使用八孔钢板和内踝经骨骺螺钉进行临时半骨骺阻滞术的结果。
在2个中心对29例（50个下肢）不同类型骨骼发育不良的患者进行内翻或外翻畸形治疗。半骨骺阻滞术时的平均年龄为10±2.9岁。共使用了66枚八孔钢板和12枚内踝螺钉。从初次手术到最近一次八孔钢板随访的平均随访时间为25±13.4个月。在手术前获取站立位全下肢前后位和侧位X线片用于畸形规划。通过机械轴偏移、机械性股骨远端外侧角、胫骨近端内侧角和胫骨远端外侧角评估X线片上的角畸形。机械轴偏移也表示为胫骨平台宽度一半的百分比，并通过确定下肢机械轴穿过的区域来对畸形程度进行分类。在膝关节的内侧和外侧均确定了4个区域，并将这些区域标记为1、2、3和4，对应畸形的严重程度。外翻对线为正值，内翻对线为负值。
将患者分为外翻组和内翻组进行分析。38个外翻下肢中有34个得到矫正，12个内翻下肢中有7个得到矫正。在外翻组中，术前和术后机械性股骨远端外侧角的平均值分别为82.1±3.7度和91.1±4.9度（P<0.001）。术前和术后胫骨近端内侧角的平均值分别为98.5±8度和87.8±7.1度（P<0.
