A 57-year-old White female sustained an open tibial fracture of her left leg as a result of a motor vehicle accident. She had a 5 × 4 cm open fracture wound in the distal third of the leg with an exposed tibial fracture site. She initially had debridement of the open tibial fracture site and placement of an external fixator by the orthopedic trauma service. A rigid fixation of the distal tibial fracture with an intramedullary rod was planned by the primary service. The plastic surgery service was consulted to provide soft tissue coverage of the distal tibial wound following a definitive rigid fixation of the fracture ( Fig. 45.1 ).
Operative Plan and Special Considerations for Reconstruction
For a relatively small open fracture wound in the distal third of the leg with the exposed fracture site and/or hardware, a proximally based medial hemisoleus muscle flap can be selected to cover the exposed fracture site and hardware. A medial hemisoleus muscle is selected to provide soft tissue coverage but also to minimize functional loss of the foot plantar flexion. The distal soleus muscle can be split longitudinally with some lateral extension so that the muscle flap would be large enough to cover adequately an open tibial fracture wound in the distal third of the leg ( Fig. 45.2 ). Based on this author’s clinical experience, the size of an open tibial wound in the distal third of the leg should be no more than 50 cm 2 when the wound is in the proximal part of the distal third leg. The distal medial half of the muscle receives blood supply primarily throughout its length by perforators arising from the posterior tibial vessels. Thus, the flap should be elevated with emphasis on the preservation of as many minor pedicles (perforators) from the posterior tibial vessels as possible to the flap while allowing adequate arc rotation of the flap to cover the wound in the distal third of the leg.
Under general anesthesia with the patient in the supine position, the open tibial fracture wound, measuring 5 × 4 cm, was debrided first after a definitive orthopedic procedure for an internal fixation of the distal tibial fracture by the orthopedic trauma service. All unhealthy-looking skin and colonized tissues were sharply debrided. The open tibial wound appeared to be fresh and clean after a definitive debridement performed by the plastic surgery service.
The flap dissection was performed under tourniquet control. An existing open wound was extended both proximally and distally. The proximal incision was extended to just above the junction of the distal and middle thirds of the leg and could be extended further proximally as needed. The distal skin incision was extended to just above the Achilles’ tendon. After identifying the medial half of the soleus muscle, it was dissected free from the flexor digitorum longus muscle ( Fig. 45.3 ). The entire distal soleus muscle near its insertion and the medial half of the soleus muscle were sharply dissected with a knife and freed from the tendon portion of the medial gastrocnemius muscle to the junction of the distal and middle thirds of the leg. Only the muscular portion of the soleus was used as the flap, while the tendon portion of both gastrocnemius muscles was left intact.
The insertion of the distal soleus muscle was divided close to the Achilles’ tendon depending on the arc of the flap rotation required. The muscle flap was elevated only to the level just at or above the level of a tibial wound where a major perforator from the posterior tibial artery to the flap was identified ( Fig. 45.4 ). This perforator served as a pivot point of the flap rotation and was carefully preserved. The flap dissection was completed with splitting the medial half (large portion) of the soleus muscle from the remaining lateral half (relatively small portion) of the muscle longitudinally to the level required by the exact location of the distal tibial wound ( Fig. 45.5 ). Therefore, the flap was based proximally and received blood supply primarily from the distal perforators of the posterior tibial vessels in the area.
The intact tendon was approximated to the remaining lateral half of the soleus muscle with nonabsorbable sutures after the flap elevation. Scoring the fascia over the deep surface of the laterally extended medial hemisoleus muscle belly could often enhance a few centimeters more arc of flap rotation. The flap was transposed into the tibial wound and inset with 3-0 absorbable half-buried horizontal mattress sutures.
One drain was placed under the flap and another drain was inserted into the flap donor site. The muscle flap was covered with a split-thickness skin graft. A split-thickness skin graft was harvested with a dermatome from the left lateral thigh and meshed to 1:1.5 ratio. The incision for the flap exposure was closed in two layers and the skin graft was secured with skin staples ( Fig. 45.6 ).
The patient did well postoperatively without any issues related to the flap reconstruction for the distal third of the leg wound closure. She was discharged from hospital on postoperative day 5. The left distal open fracture wound healed uneventfully. She was followed by the plastic surgery service for routine postoperative care and underwent an autologous bone graft procedure by the orthopedic trauma service 4 months after the initial flap reconstruction.
During further follow-up, the open tibial wound in the distal third of the leg after the flap reconstruction healed well with good contour and minimal scarring. The patient also underwent a successful bone graft procedure performed by the orthopedic trauma service. There was no wound breakdown, recurrent infection, or contour issues related to the soft tissue reconstruction ( Fig. 45.7 ). She has resumed her weight-bearing status and returned to her normal activities as instructed.
Pearls for Success
In the author’s experience, all relatively limited soft-tissue defects (<50 cm 2 ) in the distal third of the leg can be reconstructed with this laterally extended medial hemisoleus muscle flap as an alternative option to a free tissue transfer. The flap is elevated only to just at or above the level of a tibial wound where a major perforator from the posterior tibial artery to the flap is identified. This perforator often serves as a pivot point of the flap rotation and should be preserved whenever possible because it can be a critical source of blood supply to the distal portion of the flap. Preserving this important perforator, based on the author’s experience, is often possible while allowing adequate arc of flap rotation to cover the exposed tibia fracture site and hardware.
The author prefers to free the entire distal soleus muscle during the flap dissection and then split the muscle longitudinally in a more laterally extended fashion than a standard medial hemisoleus muscle flap. In this way, the distal portion of the flap can be made bigger enough and used to cover adequately a relatively larger tibial wound in the distal third of the leg. Any perforators from the posterior tibial vessels to the distal medial half of the soleus muscle just at or above the tibial wound should be preserved while allowing adequate arc of flap rotation to cover the tibial wound in the distal third of the leg. In addition, the approximation of the tendon of the medial gastrocnemius muscle to the remaining soleus muscle may minimize the functional loss of the leg after harvesting the flap. The tip necrosis of the flap, if it occurs, can be managed successfully with subsequent debridement and flap readvancement. The laterally extended medial hemisoleus muscle flap may potentially offer an alternative approach to managing Gustilo IIIB open tibial fractures in the distal third of the leg.
A 43-year-old White male developed a wound breakdown from a previous open reduction and internal fixation (ORIF) procedure of the left distal tibial after a fall. The left leg open wound was debrided by the orthopedic trauma service and left a 9 × 5 cm soft tissue defect in the distal third of the leg extending to the ankle with exposed hardware. The fracture fixation was satisfactory and there was no obvious infection. The plastic surgery service was consulted to provide soft tissue coverage for this open wound with the exposed hardware in the distal third of the leg extending to the proximal ankle ( Fig. 45.8 ).
Operative Plan and Special Considerations for Reconstruction
The distally based sural artery flap, a distant skin island flap, has frequently been used to provide soft tissue coverage for a complex wound in the distal third of the leg, if the flap donor site is available, the pedicle of the flap in the lesser saphenous vein territory is not involved by previous trauma or surgery, and the peroneal artery is patent. The flap itself provides good skin coverage to a wound in both the medial and lateral aspects of the distal leg or ankle. The donor site of a distally based sural artery flap is centrally located in the posterior calf over the medial and lateral gastrocnemius muscles. The skin island can be harvested from the proximal two-thirds of the posterior leg. The safest size for the flap is about 12 × 8 cm, but the upper limit of the flap size remains unknown. The flap receives blood supply primarily from three to six septocutaneous perforators arising from the peroneal artery in a retrograde fashion. The most proximal end of those perforators is located 4 to 7 cm proximal to the lateral malleolus. It also receives a blood supply, again in a retrograde fashion, from the fasciocutaneous perforators from the posterior tibial artery, venocutaneous perforators from the lesser saphenous vein, and neurocutaneous perforators from the sural nerve ( Fig. 45.9 ). Thus, the blood supplies to the flap are through the lesser saphenous vein and sural nerve systems that should all be included within the adipofascial pedicle when the flap is elevated. The venous outflow of the flap can either drain directly to the peroneal concomitant vein or drain back to the less saphenous vein.
Under general anesthesia with the patient in the prone position, the distal tibial wound, measuring 9 × 5 cm, was debrided. All unhealthy-looking skin edges and colonized tissues were sharply debrided. The wound appeared to be fresh and clean after a definitive debridement performed by the plastic surgery service.
The pivot point of the flap turnover was marked at 6 cm above the lateral malleolus. The entire course of the lesser saphenous vein was mapped with a handheld Doppler between the Achilles tendon and the lateral malleolus. The skin island flap was designed based on the size of soft tissue wound and the less saphenous vein should be included ( Fig. 45.10 ). Under tourniquet control, the proximal incision of the flap was made first to explore the lesser saphenous vein and its accompanying vessels. The lesser saphenous vein and its accompanying vessels were divided. The sural nerve and its accompanying vessels were exposed next through the fascia and then divided. The skin island was elevated along the subfascial plane and the flap was elevated as a fasciocutaneous island flap. The adipofascial pedicle of the flap, about 2 cm wide, was dissected free after multiple zigzag incisions distal to the skin paddle. The flap was turned over and tunneled under the skin bridge to the medial aspect of the distal leg wound.