The superficial branch of the radial nerve: An anatomic study with surgical implications

Twenty fresh cadaver extremities were dissected to delineate and quantify the course of the superficial branch of the radial nerve. This branch bifurcated from the radial nerve at the level of the lateral humeral epicondyle in eight specimens, and in all specimens the bifurcation was no more than 2.1 cm from the lateral epicondyle. It continued distally, deep to the brachioradialis and became subcutaneous a mean of 9.0 cm proximal to the radial styloid, traversing between the tendons of the brachioradialis and extensor carpi radialis longus. The superficial branch of the radial nerve branched a mean of 5.1 cm proximal to the radial styloid. Distally, at the level of the extensor retinaculum, the closest branches to the center of the first dorsal compartment and to Lister's tubercle were mean distances of 0.4 and 1.6 cm, respectively. In the hand, the superficial branch of the radial nerve most commonly supplied branches to the thumb, the index finger, and the dorsoradial aspect of the long finger. Knowledge of the course of the superficial branch of the radial nerve will help prevent injury during operative procedures on the radial side of the hand, wrist, and forearm and will aid in its localization in treatment of traumatic injuries or performance of nerve blocks in its distribution.     

Surgical exposures of the radius and ulna

The forearm contains many muscles, nerves, and vascular structures that change position on forearm rotation. Exposure of the radial shaft is best achieved with the Henry (volar) or Thompson (dorsal) approach. The volar flexor carpi radialis approaches are used increasingly for exposure of the distal radius. Although the dorsal approach is a safe utilitarian option with many applications, its use for managing fracture of the distal radius has waned. Potential complications associated with radial exposure include injury to the superficial branch of the radial nerve, the lateral antebrachial cutaneous nerve, and the cephalic vein. Dorsal and ulnar proximal radial exposures are associated with increased risk of injury to the posterior interosseous nerve. With surgical exposure of the ulna, care is required to avoid injuring the dorsal cutaneous branch of the ulnar nerve.     

带前臂外侧皮神经营养血管筋膜皮瓣的应用解剖

目的：为带前臂外侧皮神经及其营养血管筋膜皮瓣提供形态学基础。方法：在３２侧成人上肢标本上，观测前臂外侧皮神经营养血管及其周围皮肤的供血情况。结果：前臂外侧皮神经近侧的血供为肱动脉末端和桡动脉起始部的肌皮支，起始处外径分别为１．４ｍｍ、１．１ｍｍ，穿出深筋膜前长为１．９ｃｍ、１．４ｃｍ；远侧主要为桡动脉的粗大皮支，起始处外径为０．８ｍｍ，穿出深筋膜前长０．８ｃｍ；此外，桡动脉的茎突返支及掌浅支的皮支营养其远端。其神经支在神经束间或神经旁相互吻合构成纵向（链式）血管网，并借分支与筋膜皮支所形成的皮下筋膜血管网沟通。结论：可设计带前臂外侧皮神经及其营养血管的筋膜皮瓣，顺行或逆行转位修复邻近部位的软组织缺损。     

Quantitation of and superficial surgical landmarks for the anterior interosseous nerve

OBJECT: There are scant data regarding the anterior interosseous nerve (AIN) in the neurosurgical literature. In the current study the authors attempt to provide easily identifiable superficial osseous landmarks for the identification of the AIN. METHODS: The AIN in 20 upper extremities obtained in adult cadaveric specimens was dissected and quantified. Measurements were obtained between the nerve and surrounding superficial osseous landmarks. The AIN originated from the median nerve at mean distances of 5.4 cm distal to the medial epicondyle of the humerus and 21 cm proximal to the ulnar styloid process. The distance from the origin of the AIN to its branch leading to the flexor pollicis longus muscle and to the point it travels deep to the pronator quadratus (PQ) muscle measured a mean 4 and 14.4 cm, respectively. The mean distance from the AIN branch leading to the flexor pollicis longus muscle to the proximal PQ muscle was 12.1 cm, and the mean distance between this branch and the ulnar styloid process was 7.2 cm. The mean diameter of the AIN was 1.6 mm at the midforearm. CONCLUSIONS: Additional landmarks for identification of the AIN can aid the neurosurgeon in more precisely isolating this nerve and avoiding complications. Furthermore, after quantitation of this nerve, the AIN branches can be easily used for neurotization of the median and ulnar nerves, and with the aid of a transinterosseous membrane tunneling technique, passed to the posterior interosseous nerve.     

The detailed anatomy of the 1,2 intercompartmental supraretinacular artery for vascularized bone grafting of scaphoid nonunions

PURPOSE: To describe the configuration of the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA), including the location of the perforators, and to discuss the clinical use of the 1,2 ICSRA for vascularized bone grafting of scaphoid nonunions. METHODS: Thirteen fresh-frozen cadaveric forearms were used to evaluate the variations in the anatomy of the 1,2 ICSRA. After injection of red latex, the 1,2 ICSRA and its perforators were characterized and measured. Pedicle length and distal reach of the transposed 1,2 ICSRA pedicle was evaluated. We noted the relationship of the 1,2 ICSRA to the dorsal scaphoid branch of the radial artery. Another 10 specimens were injected, frozen, and sectioned to evaluate vascular penetration into the dorsal distal radius. RESULTS: The 1,2 ICSRA branched from the radial artery 1.9 mm proximal to the tip of the radial styloid (range -6.3-3.2 mm), on average. The average pedicle length was 22.5 mm (range 15-31 mm), which permits its application for both dorsal and volar scaphoid. The relationship between the origin of the 1,2 ICSRA and the dorsal scaphoid branch was categorized into 3 types, including--separate, combined, and shared. The average number of perforating vessels arising from the pedicle was 5.5 (range 3-7), with an average of 2.75 (range 1-7) perforators overlying a 1 by 0.5 cm block of the distal radius bone graft. A graft located between 8-18 mm proximal to the articular surface of distal radius would incorporate the greatest numbers of perforators. The most notable vascular penetration of the distal radius was demonstrated at 10.0 mm proximal to the radial styloid. CONCLUSIONS: The detailed anatomy of the 1,2 ICSRA presented in this study may guide in planning and dissection to maximize the vascularity of a pedicled bone graft based on this vessel for the management of scaphoid nonunions.     

Prognosis of wrist ganglion operations

A retrospective study was conducted to evaluate the results of treatment of 40 wrist ganglia operated under local anesthesia over four years. The mean follow-up period was 27 months (range 6-48 months). There were 24 dorsal and 16 volar ganglia. The mean complication rate was 56% for volar ganglia, 12.5% for dorsal ganglia, and the difference was significant (p < 0.05). The recurrence rates were 31.2% and 8.3%, respectively (mean 17.5%). There was evidence of nerve damage to the superficial branch of the radial nerve in one patient (dorsal cyst) and to the palmar cutaneous branch of the median nerve in two patients (volar cysts). The mean nerve injury rate was 7.5%. In two patients with volar ganglia, the palmar superficial branch of the radial artery was lace-rated and had to be ligated. The significantly higher complication rate after excision of volar ganglia in contrast to dorsal ones might indicate that the former should be approached more carefully in contrast to dorsal ones and preferably by a senior surgeon.     

Wrist denervation and the anterior interosseous nerve: anatomic considerations

PURPOSE: Wrist denervation via resection of the distal anterior interosseous nerve (AIN) and the posterior interosseous nerve (PIN) is an effective treatment for chronic wrist pain. When performing this procedure through a dorsal approach we have been impressed by anatomic variations of the AIN. This has raised concerns about potential denervation of the pronator quadratus (PQ). The purpose of this study was to elucidate the anatomy of the AIN and PIN as encountered through a dorsal distal forearm incision. METHODS: Ten fresh-frozen cadavers were dissected. Before dissection radiographs were obtained to ensure accurate localization of the proximal ulnar head with a radiopaque marker. A dorsal approach to the distal forearm was made to identify the anatomy of the PIN and AIN. The location and diameter of all AIN branches were noted by using an operating stereoscopic microscope at x 25 magnification and a precision caliper. The PIN anatomy and size also were noted. RESULTS: The anatomy of the AIN was variable. The average AIN diameter proximal to the PQ was 1.5 mm. The average number of AIN motor branches was 4.2. The largest PQ motor branch was the first motor branch and was located at an average distance of 37.9 mm from the proximal ulnar head. The last motor branch was found an average of 23.9 mm from the proximal ulnar head. In 9 of 10 specimens the sensory branch tunneled radially through the distal PQ and innervated the periosteum of the volar distal radius. In 4 of 10 specimens a separate branch to the distal radioulnar joint was present. We found an average PIN diameter of 0.87 mm. CONCLUSIONS: Resection of the AIN at a point 4 cm proximal to the proximal point of the ulnar head would denervate completely the PQ in our cadaver population. Division of the AIN 2 cm proximal to the ulnar head would spare most of the PQ motor branches.     

Superficial surgical landmarks for identifying the posterior interosseous nerve

OBJECT: There is a paucity of information in the neurosurgical literature regarding the surgical anatomy surrounding the posterior interosseous nerve (PIN). The goal of the current study was to provide easily recognizable superficial bone landmarks for identification of the PIN. METHODS: Thirty-four cadaveric upper extremities obtained from adults were subjected to dissection of the PINs, and measurements were made between this nerve and surrounding superficial bone landmarks. In all specimens the main radial trunk was found to branch into its superficial branch and PIN at the level of the lateral epicondyle of the humerus. Proximally, the PIN was best identified following dissection between the brachioradialis and extensor carpi radialis longus and brevis muscles. At its exit site from the supinator muscle, the PIN was best identified after retraction between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. This site was a mean distance of 6 cm distal to the lateral epicondyle of the humerus. No compression of the PIN by the tendon of origin of the extensor carpi radialis brevis muscle was seen. One specimen was found to have a proximally split PIN that provided a previously undefined articular branch to the elbow joint. The mean diameter of the PIN proximal to the supinator muscle was 4.5 mm. The leash of Henry crossed the PIN in all but one specimen and was found at a mean distance of 5 cm inferior to the lateral epicondyle. The PIN exited the distal edge of the supinator muscle at a mean distance of 12 cm distal to the lateral epicondyle of the humerus. Here the mean diameter of the PIN was 4 mm. The exit site from the distal edge of the supinator was found to be at a mean distance of 18 cm proximal to the styloid process of the ulna. This exit site for the PIN was best identified following dissection between the extensor carpi radialis longus and brevis and extensor digitorum communis muscles. The distal articular branch of the PIN was found to have a mean length of 13 cm and the proximal portion of this terminal segment was located at a mean distance of 7.5 cm proximal to the Lister tubercle. CONCLUSIONS: The addition of more anatomical landmarks can help the neurosurgeon to be more precise in identifying the PIN and in avoiding complications during surgery in this region.     

The nerve of Henlé

The nerve of Henlé, a branch of the ulnar nerve in the forearm, is thought to deliver sympathetic innervation to the ulnar artery. Forty cadaver forearms were dissected under magnification. Two distinct patterns of the nerve were found. In the typical pattern, 18 (45%) of 40 extremities, the nerve originates 16 cm proximal to the ulnar styloid, travels distally with the ulnar artery, and frequently, 13 (72%) of 18, branches to pierce the superficial fascia 6 cm proximal to the ulnar styloid and innervate the skin of the distal ulnar forearm. In the atypical pattern (12%), the nerve originates in the distal 8 cm of the forearm and travels briefly with the ulnar artery before branching to the skin. The palmar cutaneous branch of the ulnar nerve was absent in cadavers with the nerve of Henlé and may be a distal variant of that nerve.     

The dorsal branch of the ulnar nerve: an anatomic study

The dorsal branch of the ulnar nerve was dissected in 24 cadavers. The nerve arose from the medial aspect of the ulnar nerve at an average distance of 6.4 centimeters from the distal aspect of the head of the ulna and 8.3 centimeters from the proximal border of the pisiform. Its mean diameter at origin was 2.4 millimeters. The nerve passed dorsal to the flexor carpi ulnaris and pierced the deep fascia. It became subcutaneous on the medial aspect of the forearm at a mean distance of 5.0 centimeters from the proximal edge of the pisiform. The nerve gave an average of five branches with diameters between 0.7 and 2.2 millimeters. A better understanding of the anatomy of this nerve may help prevent nerve injury during surgical procedures, and can help in locating the nerve for repair of lacerations or administration of local anesthetics for regional nerve blocks.     

Anatomy of the lateral antebrachial cutaneous and superficial radial nerves in the forearm: a cadaveric and clinical study

PURPOSE: To define the anatomy of the lateral antebrachial cutaneous nerve (LACN) and the superficial radial nerve (SRN) in relation to easily identifiable landmarks in the dorsoradial forearm to minimize the risk to both nerves during surgical approaches to the dorsal radius. METHODS: In this study 37 cadaveric forearms and 20 patients having distal radius external fixation were dissected to identify these nerves in relation to various anatomic landmarks. RESULTS: Based on these dissections the anatomy was divided into 2 zones that can be identified by easily visible and palpable landmarks. Zone 1 extends from the elbow to the cross-over of the abductor pollicis longus with the extensor carpi radialis brevis and longus. Zone 2 is distal to the cross-over. In zone 1 the 2 nerves can be differentiated through limited incisions based on their depth and anatomic location. Within this zone the SRN is deep to the brachioradialis until 1.8 cm proximal to zone 2 (9 cm proximal to the radial styloid), where it becomes superficial and pierces the fascia of the mobile wad and then remains deep to the subcutaneous fat. In contrast the LACN pierces the fascia between the brachialis and biceps muscles at the level of the elbow. In all specimens the LACN ran parallel to the cephalic vein within the subcutaneous fat. In 31 specimens it ran volar to the vein and in 5 specimens the nerve crossed under the cephalic vein at the elbow and ran dorsal to the vein in the forearm. One specimen had 2 branches with 1 on either side of the vein. Differentiation of these nerves was found to be possible through limited incisions in zone 1 during placement of external fixation pins for distal radius fractures. The LACN always was located in the superficial fat running with the cephalic vein, whereas the SRN was deeper to this nerve either covered by the brachioradialis or closely adherent to it within the investing fascia of the mobile wad. In zone 2 the nerves arborized and ran in the same tissue plane, making differentiation through limited incisions difficult. CONCLUSIONS: Dividing forearm anatomy into zones aids in understanding the complex 3-dimensional anatomy. Recognition of the consistent location of both the LACN and SRN facilitates surgical exposure. This allows localization through limited incisions during nerve repair and hardware placement, thereby enhancing uncomplicated and favorable outcomes.     

Anatomy of the distal brachioradialis and its potential relationship to distal radius fracture

PURPOSE: To describe the anatomy of the brachioradialis (BR), paying special attention to its insertion in relation to the surrounding structures in cadavers and evaluating and correlating this information with a distal radius fracture pattern in a clinical population. METHODS: Eighteen fresh-frozen cadaver arms were dissected to observe the gross anatomy of the BR. The dimensions of the insertion were measured using a caliper and a 3-dimensional digitizer. The radiographs of 34 patients with 35 distal radius fractures were reviewed and the fracture pattern was compared with the normalized location of the BR insertion based on the cadaver measurements. RESULTS: On average the BR tendon inserted onto the proximal base of the first dorsal compartment 17 mm from the radial styloid tip and extended 15 mm proximally; the insertion was 11 mm wide. The BR insertion was bordered consistently by both septa of the first dorsal compartment, forming a tunnel-like structure of thick fibrous tissue on the radial aspect of the distal radius. The whole length of the tendon attached firmly to the underlying antebrachial fascia, which limited excursion. In 18 of the fractures the fracture line deviated from transverse to proximal at the radial side, forming a radial beak. The proximal tip of the beak correlated with the expected location of the proximal end of the BR tendon insertion. CONCLUSIONS: The BR distal tendon insertion is a consistent, distinct insertion at the base of the first dorsal compartment, which correlates with the radial-beak fracture pattern in approximately 50% of distal radius fractures. Cutting the BR tendon disconnects the distal fragment from the BR muscle and the forearm fascia, which may facilitate reduction of the distal radial fragments during open reduction of the distal radius fracture.     

Factors affecting forearm compartment pressures in children with supracondylar fractures of the humerus

This study evaluated forearm compartment pressures in 29 children with supracondylar humerus fractures. Pressures were measured before and after reduction in the dorsal, superficial volar, and deep volar compartments at the proximal 1/6th and proximal 1/3rd forearm. Pressures in the deep volar compartment were significantly elevated compared with pressures in other compartments. There were also significantly higher pressures closer to the elbow within each compartment. Fracture reduction did not have a consistent immediate effect on pressures. The effect of elbow flexion on post-reduction pressures was also evaluated; flexion beyond 90 degrees produced significant pressure elevation. We conclude that forearm pressures after supracondylar fracture are greatest in the deep volar compartment and closer to the fracture site. Pressures greater than 30 mm Hg may exist without clinical evidence of compartment syndrome. To avoid unnecessary elevation of pressures, elbows should not be immobilized in >90 degrees of flexion after these injuries.     

Is there a safe zone to avoid superficial radial nerve injury with Kirschner wire fixation in the treatment of distal radius? A cadaveric study

Aim of the study

To determine the relation of the superficial radial nerve to bony land-marks and to identify a safe zone for K-wire pinning in the distal radius.

Method

The superficial radial nerve was dissected in sixteen upper extremities of preserved cadavers.

Results

We found that the superficial radial nerve emerged from under brachioradialis at a mean distance of 8.45 (±1.22) cm proximal to the radial styloid. The mean distance from the first major branching point of the superficial radial nerve to the radial styloid were 4.8 ± 0.4 cm.All branches of the superficial radial nerve were found to lie in the radial half of an isosceles triangle formed by the radial styloid, Lister''s tubercle and the exit point of the superficial radial nerve. There is an elliptical area just proximal to the Lister''s tubercle. This area is not crossed by any tendons or nerve. It is bounded by the extensor carpiradialis brevis, extensor pollicis longus.

Conclusion

Pinning through the radial styloid is unsafe as the branches of the superficial radial nerve passé close to it. The ulnar half of the isosceles triangle is safe regarding the nerve. The elliptical zone just proximal to the Lister''s tubercle is safe regarding the tendons and nerve.     

Superficial radial nerve compression caused by a parosteal lipoma of proximal radius: a case report.

The superficial radial nerve might be compressed or injured at various anatomical sites along its course in the forearm. Most of the superficial radial nerve neuropathy are caused by pathological lesions such as trauma, a mass or tight band at the distal third of the forearm. Wartenberg's syndrome is the most common cause of sensory radial entrapment at the distal forearm. Compression of superficial radial nerve occurring at the proximal third of forearm is unusual. We present a rare case of superficial radial nerve compression due to a parosteal lipoma of proximal radius. Results of complete physical and radiological examinations are also presented. Surgical intervention of the tumour mass was performed for nerve decompression. The patient reported total relief of the neurological symptom post-operatively. This rare case demonstrates the unique characteristics of parosteal lipoma with unusual superficial radial nerve neuropathy at the proximal radius. This report reminds us that there is the possibility of superficial nerve compression caused by tumour mass over the proximal third of forearm.     

Anatomic relations between the cephalic vein and the sensory branches of the radial nerve: How can nerve lesions during vein puncture be prevented?

The cephalic vein of the forearm is often used for IV catheters because of its ease of access for peripheral venous cannulation. But its close relation to the sensory branch of the radial nerve sometimes causes it to be damaged when the vein is cannulated. Our anatomic study conducted on 33 specimens confirmed the risk of nerve lesion. However, it is impossible to define a safe zone, because of the randomly located nerve and vein crossing zones, where the iatrogenic risk of damaging the radial nerve is maximum. We suggest that to avoid incidents, the cephalic vein should be punctured above the emergence of the sensory branch of the radial nerve, e.g., at least 12 cm above the level of the styloid process of the radius. IMPLICATIONS: We attempted to determine the relationship between the cephalic vein and the sensory branch of the radial nerve at the wrist to help prevent lesions of the radial nerve when the cephalic vein is cannulated. We examined the anatomy of 33 postmortem specimens and suggest that puncture of the cephalic vein 12 cm or more proximal to the styloid process can prevent radial nerve lesions.     

The dorsal cutaneous branch of the ulnar nerve. An anatomic clarification with six case reports

We studied the anatomy and pathology of the dorsal cutaneous branch of the ulnar nerve by dissecting 10 fresh cadaver upper limbs and reviewing 6 cases of injury or entrapment of the dorsal cutaneous branch of the ulnar nerve. In all of the cadavers and in our series of cases, several anatomical features were apparent: 1) the dorsal cutaneous branch of the ulnar nerve arises from the main ulnar nerve an average of 5.5 centimeters proximal to the head of the ulna; 2) the dorsal cutaneous branch of the ulnar nerve reaches the dorsum of the hand after coursing volar to the ulnar head; 3) there was no communication between the dorsal cutaneous branch of the ulnar nerve and the superficial sensory branch of the radial nerve; and 4) no volar branches were noted. Based on our experience, disorders of this nerve are more prevalent than previously reported. This clarification of the anatomy will help prevent unnecessary injury during surgery and will be valuable in the diagnosis of disorders of the dorsal cutaneous branch of the ulnar nerve.     

正中神经指浅屈肌肌支移位修复尺神经运动支的应用解剖

目的 通过对正中神经指浅屈肌肌支和尺神经运动支的解剖学研究,为正中神经指浅屈肌肌支移位修复尺神经运动支,恢复手内在肌功能的临床应用提供解剖学基础.方法 选用20例40侧近期经福尔马林浸泡固定的成人上肢标本,暴露正中神经、尺神经,测量正中神经指浅屈肌肌支各项解剖学数据;应用图像分析系统对组织切片做定量分析,测算该肌支有髓神经纤维数目.临床模拟操作正中神经指浅屈肌肌支移位修复尺神经运动支.结果 正中神经第4肌支发出部位距离桡骨茎突和尺骨茎突连线(48.4±2.4)mm,入肌部位距离桡骨茎突和尺骨茎突连线(21.4±1.8)mm,可分离长度(27.1±1.2)mm,横径(1.2±0.2)mm,前后径(0.7±0.1)mm;尺神经的运动支和感觉支之间自然分束无损伤分离.长度为(7.1±0.70)cm;组织切片及图片系统测得正中神经指浅屈肌第4肌支有髓神经纤维数目为(1378.9±107.9)条.结论 正中神经指浅屈肌第4肌支可修复尺神经运动支,以期恢复手内在肌的功能.     

The posterior interosseous artery in the distal part of the forearm. Is the term "recurrent branch of the anterior interosseous artery" justified?

In 1993 Angrigiani raised the question as to whether the distal part of the posterior interosseous artery (AIP) is a recurrent branch of the anterior interosseous artery (AIA) and forms a "choke"--anastomosis with the AIP in the middle of the forearm. A dissection study was conducted on 66 upper extremities to evaluate the diameters of the dorsal branch of the anterior interosseous artery, the anastomotic branch, the diameter of the posterior interosseous artery at the point of origin of the septocutaneous perforators in the middle of the forearm and the diameter of the posterior interosseous artery at the point of emergence in the dorsal compartment. We further tried to identify different forms and types of the "distal" anastomosis and the connections to the dorsal carpal arch and the ulnar artery. A distal anastomosis between the AIA and AIP was found in 65 of the 66 upper extremities. Three different types of anastomosis could be identified. The smallest diameter was found at the middle of the forearm (mean diameter AIA 1.28 mm; anastomotic branch 0.6 mm; AIP at the middle of the forearm 0.39 mm; AIP prox. 1.35 mm). A branch through the fifth extensor compartment was present in all of our specimens (mean diameter 0.54 mm). A branch through the forth extensor compartment could be found in 16 specimens. Based on our findings and the embryological development, we conclude that the AIP is only present in the proximal half of the forearm. In the distal part, the dorsal branch of the anterior interosseous artery forms a vascular arcade, which gives off branches to the dorsal carpal arch, the ulnar head and the ulnar artery. This arcade anastomoses with the posterior interosseous artery in the middle of the forearm by means of a choke anastomosis. We also conclude that the term "recurrent branch of the anterior interosseous artery" for the distal part of posterior interosseous artery is correct.     

The relationship of the Phantom® Lapidus Intramedullary Nail System to neurologic and tendinous structures in the foot: An anatomic study

BackgroundThe purpose of our cadaveric study was to determine the proximity of nail insertion and interlocking mechanisms in the Phantom® Lapidus Intramedullary Nail System to neurologic and tendinous structures in the foot.MethodsWe used 10 fresh-frozen human lower-extremity specimen cadavers. For each specimen, the Nail System was inserted as described in the published technique guide. We then performed dissection on the tibialis anterior tendon, extensor hallucis longus tendon, and medial dorsal cutaneous branch of the superficial peroneal nerve and we measured and averaged the distances from each of these structures from the nail.ResultsThe tibialis anterior tendon was in closest proximity to the insertion of the proximal medial interlock K-wire with an average distance of 0.4 mm from the tendon. The extensor hallucis longus tendon was in closest proximity to nail insertion with an average distance of 1.2 mm. The medial dorsal cutaneous branch of the superficial peroneal nerve was in closest proximity to the distal interlock K-wire with an average distance of 7.5 mm.ConclusionsThe tibialis anterior tendon, extensor hallucis longus tendon, and the medial dorsal cutaneous branch of the superficial peroneal nerve are at risk with the insertion of the nail system. Blunt dissection should be performed using this system with a path to bone before instrumentation to reduce the risk of nerve and tendon injury in the foot.