Hypoplastic posterior tibial artery overlooked as a posttraumatic vascular injury: two case reports

Article information

Arch Hand Microsurg. 2026;31(1):48-54

Publication date (electronic) : 2026 February 23

doi : https://doi.org/10.12790/ahm.25.0021

Nae-Ho Lee, Jung Kyun Park, Jin Yong Shin, Yoon Kyu Chung, Si-Gyun Roh

Department of Plastic and Reconstructive Surgery, Jeonbuk National University Hospital, Jeonju, Republic of Korea

Corresponding author: Si-Gyun Roh Department of Plastic and Reconstructive Surgery, Jeonbuk National University Hospital, 20 Geonji-ro, Deokjin-gu, Jeonju 54907, Korea Tel: +82-63-250-1865 Fax: +82-63-250-1866 E-mail: pssroh@jbnu.ac.kr

Received 2025 July 17; Revised 2025 November 13; Accepted 2025 November 20.

Abstract

Introduction

We present cases of patients requiring reconstruction of lower leg defects caused by trauma. In such cases, the available soft tissue around the ankle is often insufficient, and vascularity tends to diminish distally. Moreover, although we typically assume that the poor vascular status is due to prior trauma, we may sometimes discover that it results from a congenital anomaly. Vascular anomalies in the lower extremities present unique challenges for reconstructive surgeons. Consequently, inadequate recipient vessels can lead to complications such as arterial occlusive disease and arterial insufficiency. Therefore, careful preoperative planning is essential to determine the appropriate surgical method. Herein, we report two cases of patients who presented with tibiofibular fractures and associated soft tissue defects in the lower leg.

This study was approved by the Institutional Review Board of Jeonbuk National University Hospital and conducted in accordance with the principles of the Declaration of Helsinki. Written informed consent was obtained from each patient before inclusion in the study.

Case report

1. Case 1

A 35-year-old man was involved in a motorcycle accident and admitted to the orthopedic department with a comminuted fracture of the left tibia and fibula (Fig. 1). Emergency surgery was performed for external fixation of the tibia and fibula, arteriorrhaphy of the posterior tibial artery (PTA), and ligation of the saphenous vein. The patient was then referred to our department for reconstruction of a defect on the medial side of the left lower leg (Fig. 2).

Fig. 1.

Photograph (A) and X-ray image (B) of the lower leg with a left tibiofibular comminuted fracture.

Fig. 2.

Preoperative photograph showing a defect on the medial side of the lower leg.

Preoperative lower extremity computed tomography (CT) angiography revealed poor blood flow in the PTA but no apparent stenosis in either the PTA or the proximal portion of the peroneal artery (Fig. 3). Initially, we attributed the poor circulation to the motorcycle-related trauma. Although the imaging suggested suboptimal perfusion, the PTA was selected as the recipient vessel for the anterolateral thigh (ALT) free flap because it is generally considered reliable, offering consistent blood flow, an appropriate vessel caliber, and easy accessibility for tension-free anastomosis. However, intraoperatively, we discovered hypoplasia of the PTA and found no suitable, well-vascularized recipient vessels capable of providing sufficient blood flow for an end-to-end anastomosis. Typically, traumatic vessel injury presents with abrupt luminal narrowing, wall disruption, or perivascular hematoma, often accompanied by tissue inflammation or swelling. In contrast, congenital hypoplasia is characterized by a uniformly small-caliber but intact vessel with preserved wall structure and rich collateral circulation, while adjacent soft tissues remain unaffected. These intraoperative findings supported our diagnosis of congenital PTA hypoplasia in this case. The anterior tibial artery (ATA) was not chosen as the recipient vessel due to its deeper location and limited accessibility within the injury zone. Conversely, the popliteal artery provided a healthier proximal inflow source suitable for constructing an arteriovenous (AV) loop. Therefore, we modified our plan to perform an end-to-end anastomosis between the lateral circumflex femoral artery (LCFA)—the donor artery of the ALT free flap—and the popliteal artery, creating a one-stage AV loop using the lesser saphenous vein harvested from the opposite calf (Fig. 4).

Fig. 3.

Lower extremity computed tomography angiography shows scanty blood flow (arrow) of the posterior tibial artery.

Fig. 4.

Intraoperative photographs showing (A) posterior tibial artery hypoplasia and (B) anastomosis using an arteriovenous loop.

Under microscopic guidance, an end-to-end anastomosis was performed between the popliteal artery and the lesser saphenous vein, which was connected to the popliteal vein. After confirming adequate flow through the AV loop, we bisected it at its midpoint. Subsequently, we completed an end-to-end anastomosis between the popliteal artery and the lesser saphenous vein connected to the LCFA. Venous anastomosis was also performed in an end-to-end fashion between the vena comitans and the lesser saphenous vein, which was connected to the popliteal vein. The isolated ALT flap was then transferred to cover the defect area (Fig. 5).

Fig. 5.

Postoperative photograph after the anterolateral thigh flap transfer using the arteriovenous loop.

Postoperatively, the patient recovered well without any complications. He expressed satisfaction with the successful outcome of the surgery, which preserved his leg length despite the challenging vascular condition. During the 6-month follow-up period, the patient maintained normal daily activities without any notable complications and achieved complete recovery.

2. Case 2

A 15-year-old girl was brought to the emergency room after sustaining injuries in an accident while riding a personal mobility device (kickboard). She was admitted to the orthopedic department with an open fracture of the left tibia and fibula (Fig. 6). After external fixation of the tibia and fibula, the patient was transferred to our department for reconstruction of the defect on the anterior aspect of the left lower leg (Fig. 7).

Fig. 6.

Photograph (A) and X-ray image (B) of lower leg with a left tibiofibular comminuted fracture.

Fig. 7.

Preoperative photograph showing a defect on the anterior side of the lower leg.

Lower extremity CT angiography revealed poor blood flow in the PTA, which we initially attributed to the previous accident (Fig. 8). Given the proximity of the soft tissue defect to the ankle joint and the exposed tibia, we planned an ALT free flap for reconstruction of the defect. Initially, the PTA was selected as the recipient vessel. However, during surgery, we found that the reduced blood flow in the PTA was due to overall vessel hypoplasia rather than trauma (Fig. 9). Therefore, we selected the ATA and the accompanying anterior tibial vein as the recipient vessels, as they did not exhibit hypoplasia. Under microscopic guidance, the descending branch of the LCFA and the ATA were anatomically positioned within an appropriate distance to permit pedicle inset without the need for an AV loop. The diameters of the donor and recipient vessels were comparable, enabling an end-to-end anastomosis to be performed without difficulty. The isolated ALT flap was then transferred to the defect area (Fig. 10).

Fig. 8.

Lower extremity computed tomography angiography shows scanty blood flow (arrow) of the posterior tibial artery.

Fig. 9.

Intraoperative photograph showing the posterior tibial artery hypoplasia.

Fig. 10.

Postoperative photograph after anterolateral thigh flap transfer using the anterior tibial artery as the recipient vessel.

Postoperatively, the patient was satisfied with the successful outcome despite the challenging vascular condition. Recovery was smooth, with no complications such as flap necrosis. During the 6-month follow-up period, she resumed normal daily activities without difficulty and remained free of complications.

Discussion

According to the cadaveric study by Ongsiriporn et al. [1], which examined congenital variations in popliteal vasculature relevant to fibular free flap reconstruction, 162 lower extremities excised from 81 cadavers aged 23 to 100 years were analyzed. The most common popliteal artery branching pattern was type I A, where the ATA arises first, followed by the tibioperoneal trunk that divides into the PTA and the peroneal artery, accounting for 90.7% of cases. Vascular anomalies were identified in 15 of the 162 limbs (9.3%). The most frequent variant was type III A, characterized by hypoplasia or aplasia of the PTA, observed in 6.2% of limbs, followed by type I-B, involving triplication of the ATA, peroneal artery, and PTA (Table 1, Fig. 11) [1-3]. In limbs with type III A–C deformities, the peroneal artery may assume a greater role in supplying blood to the foot, compensating for diminished tibial arterial flow. Although most variations were unilateral, a dominant peroneal artery was bilateral in 20% of cases [3]. In our cases, both lower extremities exhibited vascular anatomy consistent with the type III A pattern, showing PTA hypoplasia with compensatory peroneal dominance. Although this pattern was definitively identified intraoperatively, preoperative CT angiography findings of reduced PTA flow retrospectively correlated with this hypoplastic anatomy.

Table 1.

Types of popliteal artery branching patterns: classification by Kim et al. [2] and Abou-Foul et al. [3]

Fig. 11.

An illustration of the popliteal artery and its branches following classification by Kim et al. [2] and Abou-Foul et al. [3] (used with permission from the copyright holder). PTA, posterior tibial artery; PR, peroneal artery; ATA, anterior tibial artery.

In patients with vascular anomalies or compromised blood flow, thorough physical and imaging assessments are essential to confirm adequate vascular anatomy before surgery [4]. A physical examination alone may not reveal vascular variations; therefore, preoperative vascular imaging of the lower limb is generally recommended, even in patients without peripheral vascular disease. The need for routine preoperative vascular mapping remains debated in the literature [3]. If preoperative CT angiography is not mandated, the authors suggest considering an optional CT angiography policy. At our institution, preoperative CT angiography is routinely performed for all free flap reconstructions to evaluate recipient vessel integrity. In trauma cases, CT angiography is essential to assess vessel continuity and flow, exclude total rupture or obstruction, and ensure adequate vascular supply prior to reconstruction, underscoring the importance of meticulous vascular assessment [1,3].

A healthy recipient vessel is essential for successful flap survival. In complex cases—such as those involving severe trauma, prior radiation, or vascular disease—suitable vessels near the defect may not be available. In such situations, an AV loop can be used to extend the vascular reach and ensure reliable inflow and outflow. Compared with traditional vein grafts, AV loops allow easier adjustment of length, reduce ischemic time, and provide more stable blood flow. Cavadas [5] reported favorable outcomes using AV loops in extremity reconstruction and Lind et al. [6] achieved a 91% limb-salvage rate in trauma patients treated with this technique, underscoring its reliability in complex reconstructive settings. In addition, Cho et al. [7] highlighted the effectiveness of a one-stage AV loop technique in poorly vascularized lower extremities. The one-stage AV loop enables tension-free anastomosis outside the injury zone and allows immediate use of the vein graft, thereby reducing ischemic time and optimizing flap perfusion. It also provides several advantages over traditional two-stage procedures, including technical simplicity and a lower risk of complications such as flow “steal” phenomena [5,6].

In our case, two separate interpositional vein grafts were initially considered; however, an AV loop was ultimately chosen. The use of dual vein grafts would have required multiple anastomoses, prolonged ischemic time, and limited the ability to assess intraoperative flow dynamics, thereby increasing the risk of thrombosis and technical failure. In contrast, the AV loop allowed immediate perfusion testing through a single proximal anastomosis, enabling verification of graft patency and adjustment of length before final division. This approach provided a more stable hemodynamic environment and permitted a tension-free end-to-end anastomosis outside the injury zone. Given the intraoperatively identified hypoplasia of the PTA, the AV loop proved to be a reliable alternative conduit and particularly advantageous for maintaining adequate flow in a compromised vascular setting.

In current clinical practice, when planning free flap surgery, perforators are localized using sonography, and flap survival is enhanced through color Doppler monitoring before, during, and after the procedure. Doppler sonography allows measurement of the time-averaged maximum velocity of blood flow, and flow volume can be estimated based on the cross-sectional area. This technique is also valuable for assessing vascular status [8-10]. Beyond simple perforator mapping, Doppler sonography can assist in distinguishing traumatic vessel injury from congenital hypoplasia. Traumatic vessel injury typically presents with abrupt changes in luminal diameter, discontinuous flow, or marked velocity variations caused by wall disruption or thrombus formation. In contrast, congenital hypoplasia is characterized by a consistently small-caliber vessel with a continuous flow pattern and preserved wall integrity. Therefore, careful preoperative Doppler assessment can provide valuable diagnostic clues for anticipating whether poor vascular flow results from trauma-related injury or an underlying congenital anomaly.

Article information Continued