Foot & Ankle Unit, Royal National Orthopaedic Hospital, Stanmore, United Kingdom.
Department of Orthopaedics & Musculoskeletal Science, University College London, London, United Kingdom.
Foot Ankle Int. 2024 Jul;45(7):746-756. doi: 10.1177/10711007241242779. Epub 2024 Apr 15.
The cavovarus foot is a complex 3-dimensional deformity. Although a multitude of techniques are described for its surgical management, few of these are evidence based or guided by classification systems. Surgical management involves realignment of the hindfoot and soft tissue balancing, followed by forefoot balancing. Our aim was to analyze the pattern of residual forefoot deformities once the hindfoot is corrected, to guide forefoot correction.
We included 20 cavovarus feet from 16 adult patients with Charcot-Marie-Tooth who underwent weightbearing CT (mean age 43.4 years, range: 22-78 years, 14 males). Patients included had flexible deformities, with no previous surgery. Using specialized software (Bonelogic 2.1, Disior) a 3-dimensional, virtual model was created. Using morphologic data captured from normal feet in patients without pathology as a guide, the talonavicular joint of the cavovarus foot was digitally reduced to a "normal" position to simulate the correction that would be achieved during surgical correction. Models of the corrected position were exported and geometrically analyzed using Blender 3.64 to identify anatomical trends.
We identified 4 types of cavovarus forefoot morphotypes. Type 0 was defined as a balanced forefoot (2 cases, 10%). Type 1 was defined as a forefoot where the first metatarsal was relatively plantarflexed to the rest of the foot, with no significant residual adduction after talonavicular joint correction (12 cases, 60%). Type 2 was defined as a forefoot where the second and first metatarsals were progressively plantarflexed, with no significant adduction (4 cases, 20%). Type 3 was defined as a forefoot where the metatarsals were adducted after talonavicular derotation (2 cases, 10%).
In this relatively small cohort, we identified 4 forefoot morphotypes in cavovarus feet that might help surgeons to recognize and anticipate the residual forefoot deformities after hindfoot correction. Different treatment strategies may be required for different morphotypes to achieve balanced correction.
Level IV, retrospective case series.
马蹄内翻足是一种复杂的三维畸形。尽管有多种手术技术用于治疗马蹄内翻足，但其中很少有基于分类系统或循证医学的技术。手术治疗包括跟骨矫形和软组织平衡，然后是前足平衡。我们的目的是分析跟骨矫正后前足残余畸形的模式，以指导前足矫正。
我们纳入了 16 例成年 Charcot-Marie-Tooth 患者的 20 只马蹄内翻足，这些患者均接受了负重 CT 检查（平均年龄 43.4 岁，范围：22-78 岁，男性 14 例）。纳入的患者均有柔韧性畸形，且无既往手术史。使用专门的软件（Bonelogic 2.1、Disior），创建一个三维虚拟模型。利用患者中无病理的正常足部的形态数据作为指导，将马蹄内翻足的距下关节数字化还原至“正常”位置，以模拟手术矫正时可实现的矫正效果。导出矫正后的模型，并使用 Blender 3.64 进行几何分析，以识别解剖学趋势。
我们确定了 4 种马蹄内翻足前足畸形类型。0 型定义为平衡前足（2 例，10%）。1 型定义为第一跖骨相对于其余足部相对跖屈，距下关节矫正后无明显内收（12 例，60%）。2 型定义为第二和第一跖骨逐渐跖屈，无明显内收（4 例，20%）。3 型定义为距下关节旋转后，跖骨内收（2 例，10%）。
在这个相对较小的队列中，我们确定了马蹄内翻足的 4 种前足畸形类型，这可能有助于外科医生识别和预测跟骨矫正后前足残余畸形。不同的畸形类型可能需要不同的治疗策略来实现平衡矫正。
IV 级，回顾性病例系列。
