ABSTRACT:
A 33-year-old male patient developed distal femur chronic osteomyelitis with massive
bone loss after an open grade-3b fracture. Following several failed treatments to
eradicate infection, a tibial turn-up procedure was performed to provide a stable
and functional stump. To avoid neurovascular problems, the popliteal vessels and sciatic
nerve were moved medially, and the flap was rotated externally to decrease the collapse.
The progression after surgery was satisfactory, no vascular or neurological claudication
was observed, and the patient has been able to wear an external prosthesis after flap
healing. Tibial turn-up plasty is a rarely described reconstructive technique capable
of providing longer stumps. The releasing and medialization of popliteal vessels,
with axial rotation of the flap, may prevent the development of neurovascular impingement.
Keywords: amputation stumps; bone transplantation; osteomyelitis; surgical flaps.
RESUMO:
Um paciente do sexo masculino, de 33 anos, apresentou osteomielite crônica do fêmur
distal com perda óssea maciça após fratura exposta de grau 3b. Após vários tratamentos
ineficazes para erradicar a infecção, foi realizado um procedimento de aumento da
tíbia para proporcionar um coto estável e funcional. Para evitar problemas neurovasculares,
os vasos poplíteos e o nervo ciático foram movidos em sentido medial e o retalho foi
rotacionado externamente para diminuição do colapso. A evolução após a cirurgia foi
satisfatória; não houve claudicação vascular ou neurológica, e o paciente pôde usar
prótese externa após a cicatrização do retalho. A plastia tibial é uma técnica reconstrutiva
raramente descrita, que pode aumentar o comprimento dos cotos. A liberação e medialização
dos vasos poplíteos, com rotação axial do retalho, pode prevenir o desenvolvimento
de impacto neurovascular.
Palavras-chave: cotos de amputação; osteomielite; retalhos cirúrgicos; transplante ósseo.
FIGURES
| Citation: Rincon MRM, Gomez-Ricaurte OF, Riveros-Riveros HA, Sambri A. Popliteal Neurovascular Bundle Medialization and Axial Flap Rotation to Avoid Bone Impingement in Tibial Turn-up Plasty: A Case Report. 59(Suppl 2):163. doi:10.1055/s-0044-1779308 |
| Financial Support The authors declare that the present research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. |
| Note: Work carried out at the Clinica Nueva, Calle, Bogotá, Colombia. |
|
Conflito de Interesses Os autores declaram que não há conflito de interesses. |
| Received: March 09 2023; Accepted: May 29 2023 |
INTRODUCTION
Tibial turn-up is a uncommon type of amputation-rotationplasty that has several potential indications.1 The objective of this technique is to develop a longer and functional stump, using the patient's leg or foot to reconstruct femoral or tibial defects.2 Since the first report by Sauerbruch,3 less than 30 cases have been published. It differs from a Van Nes rotationplasty4 regarding the axis of rotation, as the leg is turned 180° over the thigh in the coronal plane instead of the axial plane.
Due to the very rare indication for this surgery, very little information has been written regarding the management of the neurovascular bundle. The purpose of the present paper is to describe an approach to the tibial turn-up technique to avoid impingement of the popliteal vessels and sciatic nerve.
CASE REPORT
Ethical clearance for the study was obtained from the institutional Ethics in Research Committee on September 12, 2022, and written informed consent was obtained from the patient.
A 33-year-old male patient sustained a Grade-IIIB open fracture of the distal femur and patella after a motorcycle accident in a rural area. He was initially treated in a low-complexity rural center through external fixation and several debridements due to gross contamination. As the process could not be managed locally, the patient was referred to our institution with a diagnosis of soft-tissue sepsis and osteomyelitis.
A distal femoral resection was required due to bone necrosis and persistence of the sepsis after wide-spectrum antibiotics and debridements. A temporary cement spacer was placed, and control of the septic process was achieved.
The wounds healed and the hardware remained stable during a six-week antibiotic course. Patellar osteosynthesis was performed to preserve the extensor mechanism. The patient remained with the fixator for six months due to loss to follow-up. At that point, the implants were removed and converted into a new spacer over a long intramedullary nail for arthrodesis.
The patient decided to continue with the spacer, but after one year the infection reactivated (►Fig. 1A). Considering the difficulties to reconstruct the femur, soft-tissue compromise, and extension of the infection (►Fig. 1B), the patient selected an ablative surgery. A tibial turn-up plasty was proposed to preserve length, following a debridement with samples, and a new antibiotic scheme.

In the final surgery, the hardware was removed, and the tibial/femoral canals were cleaned using an irrigation-aspiration system (Reamer Irrigator Aspirator [RIA], Johnson & Johnson MedTech, New Brunswick, NJ, United States). The flap was designed, resecting the anterolateral thigh skin, patella, ligaments, proximal and distal thirds of the tibia, the fibula, and the anterior part of the skin of the leg skin and foot (►Fig. 2A). The anterior tibial periosteum was preserved by removal of the tibialis anterior muscle (►Fig. 2B).

The tibialis vessels were tied distally; the popliteal vessels and sciatic nerve were identified and medially moved in the flexion area of the flap (►Fig. 2C and 2D). The remaining tibia was adjusted and fixed to the femur with a 4.5-mm titanium dynamic compression plate (DCP) (Königsee Implantate GmbH, Allendorf, Hessen, Germany), after rotating the flap 45° in the axial plane (►Figs. 2E and 3). The soft tissue and skin were closed in a normal fashion.

An uneventful recovery was observed, with bone consolidation at six months, (►Fig. 4). The patient was followed up for more than 40 months. He is fully recovered and is able to perform his activities with an external prosthesis (►Fig. 5A and 5B).


DISCUSSION
Tibial turn-up is a highly uncommon type of surgery performed when no other reconstructive alternatives are available.5 Although it is an ablative intervention, its main objective is to develop longer amputation stumps, when total or almost total resection of the femur or tibia must be performed.6
Due to the anatomical repairs in this reconstruction, the popliteal vessels and sciatic nerve will lie behind the tibial segment after the flap inversion. Therefore, there is a risk of impingement with vascular or neurological claudication following the prosthetic fitting.
Since the first report by Ferdinand Sauerbruch in 1922,3 a total of 18 papers have been published in indexed databases. (PubMed, Hinari, ScienceDirect). The description of the proper management of the popliteal neurovascular bundle is available only in two7,8 of those reports.
In the first one, Peterson et al.7 mentioned that popliteal vessels may need to be freed for 8 cm to 10 cm at the point of rotation, to avoid tethering with the tibia. No further description was made regarding the neurovascular management.
In the second one, McDonald et al.,8 described a pedicled tibial bone flap without soft tissue. Although the usefulness of medializing the vascular component is mentioned in this paper, this technique depends on thigh flaps and sacrifices the sciatic nerve. Therefore, their observations cannot be evaluated in the conventional Sauerbruch reconstruction.
In the case herein reported, releasing the popliteal artery and sciatic nerve at the area of flexion enabled its medial displacement, avoiding impingement with the bone. Additionally, rotating the flap 45° in the axial plane increased the length of the vessel and nerve, decreasing the possible loop collapse.
In conclusion, tibial turn-up is a very useful but not frequently used last resource technique to reconstruct long femoral stumps. Although several modifications can be made,9 the medialization and relative elongation of the neurovascular structures by rotating the flap seem to be a useful strategy to prevent bone impingement with early or late complications in the stump.




