Kaplan Nathan, Fowler Xavier, Maqsoodi Noorullah, DiGiovanni Benedict, Oh Irvin
1 Department of Orthopaedics and Rehabilitation, University of Rochester Medical Center, Rochester, NY, USA.
2 School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA.
Foot Ankle Int. 2017 Apr;38(4):424-429. doi: 10.1177/1071100716682993. Epub 2016 Dec 1.
Isolated gastrocnemius contracture (IGC) is associated with various foot and ankle pathologies. To address the problem of IGC, a number of gastrocnemius lengthening procedures have been described. Although proximal medial gastrocnemius recession (PMGR) has shown to be an effective operative treatment for IGC, it poses risks to various anatomic structures around the knee joint and requires the patient to be positioned prone. As an alternative, we proposed to release the medial gastrocnemius at the division between the proximal one-third and distal two-thirds of the gastrocnemius muscle to correct equinus contracture, while minimizing risk to other structures. The aim of this study was to describe an anatomic basis for a medial gastrocnemius recession (MGR) and to investigate the anatomic structures at risk in comparison to PMGR.
Eight cadaveric lower leg specimens were used in the study. The standard PMGR and the novel MGR were performed on each specimen. After completion of the 2 procedures, complete dissection was performed to investigate the distances between surgically released fascia margins and surrounding anatomic structures, including the greater saphenous vein, small saphenous vein, saphenous nerve, medial sural cutaneous nerve, semimembranosus tendon, tibial nerve, and popliteal artery. The mean distances were calculated and the shortest distances for each structure were reported.
Proximities of anatomic structures to surgically released gastrocnemius fascia at the medial and lateral margins were notably different between the 2 techniques. For the PMGR, the semimembranosus tendon (95% confidence interval of 2.4-7.4 mm), small saphenous vein (3.4-10.0 mm), popliteal artery (3.9-9.3 mm), and tibial nerve (5.0-11.1 mm) were in greater proximity to the operative margin. For the MGR, the greater saphenous vein (5.3-17.6 mm) and saphenous nerve (5.1-18.6 mm) were at greater risk.
MGR at the proximal one-third of the gastrocnemius muscle may be a safe alternative for operative treatment of IGC.
We identified the major structures at risk when performing the proximal medial gastrocnemius release and propose a novel, possibly safer alternative for the medial gastrocnemius release.
孤立性腓肠肌挛缩（IGC）与多种足踝部病变相关。为解决IGC问题，已描述了多种腓肠肌延长手术。尽管近端内侧腓肠肌松解术（PMGR）已被证明是治疗IGC的有效手术方法，但它对膝关节周围的各种解剖结构构成风险，且需要患者俯卧位。作为一种替代方法，我们建议在腓肠肌近端三分之一和远端三分之二交界处松解内侧腓肠肌以纠正马蹄足挛缩，同时将对其他结构的风险降至最低。本研究的目的是描述内侧腓肠肌松解术（MGR）的解剖学基础，并与PMGR相比，研究存在风险的解剖结构。
本研究使用了8个尸体小腿标本。对每个标本进行标准的PMGR和新的MGR。完成这两种手术后，进行完整的解剖以研究手术松解的筋膜边缘与周围解剖结构之间的距离，包括大隐静脉、小隐静脉、隐神经、腓肠内侧皮神经、半膜肌腱、胫神经和腘动脉。计算平均距离并报告每个结构的最短距离。
两种技术在内侧和外侧边缘处，解剖结构与手术松解的腓肠肌筋膜的接近程度明显不同。对于PMGR，半膜肌腱（95%置信区间为2.4 - 7.4毫米）、小隐静脉（3.4 - 10.0毫米）、腘动脉（3.9 - 9.3毫米）和胫神经（5.0 - 11.1毫米）更靠近手术边缘处。对于MGR，大隐静脉（5.3 - 17.6毫米）和隐神经（5.1 - 18.6毫米）面临的风险更大。
在腓肠肌近端三分之一处进行MGR可能是治疗IGC的一种安全替代方法。
我们确定了进行近端内侧腓肠肌松解时存在风险的主要结构，并提出了一种新的、可能更安全的内侧腓肠肌松解替代方法。
