British j%urnal of Plastic Surgery (IgTg), 32, 184-187
TENSOR
FASCIA
LATA:
NEUROSENSORY
MUSCULO-CUTANEOUS
FREE FLAP
By STEPHENJ. MATI-IES, M.D. and ROBERTT. BUCHANAN, M.D. Division of Plastic and Reconstructive Surgery, Washington University, School of Medicine, St Louis, Missouri 63110, U.S.A.
THE tensor fascia lata (TFL) musculo-cutaneous flap has great potential as a flap for microsurgical transfer (Hill et al., 1978). This unit consists of a small antero-lateral thigh muscle, the ilio-tibia1 tract or fascia lata, and their associated cutaneous territory. Although the TFL is small, the distal muscle arterial perforators extend axially along the fascia lata supporting a large cutaneous territory. The cutaneous territory extends from the iliac crest to within 5 cm of the knee centred over the muscle and distal fascia lata (Fig. IA). Furthermore, the unit is thin consisting mainly of fascia lata, subcutaneous fat, and skin (Fig. 2C). Vascular pedicle. The TFL unit is vascularised by the terminal branch of the lateral circumflex femoral artery. This artery is a branch of the profimda femoris and courses beneath the rectus femoris muscle entering the medial anterior belly of the TFL (Fig. IA). With division of the descending branch of the lateral circumflex femoral artery, a long pedicle of 5 to 6 cm may be obtained. The pedicle which enters the muscle IO cm inferior to the anterior superior iliac crest is safely located by medial retraction of the rectus femoris muscle. This artery with associated vein has an external lumen diameter of 1.8 to 2.0 mm. By division of the TFL proximal to the inferior terminal branch of its vascular pedicle, the majority of the muscle is left in place (Fig. IB). This manoeuvre both decreases the bulk of the proximal flap and eliminates a depression in the donor area at the proximal lateral thigh. Sensory nerve. A neurosensory free flap is possible by incorporating the sensory nerves to this unit’s cutaneous territory (Fig. IC). The lateral cutaneous femoral nerve (branch of second and third lumbar nerves) supplies sensation to the distal two-thirds of the cutaneous territory of the TFL unit. The nerve enters the cutaneous territory of the flap IO cm below the anterior superior iliac crest and can be identified at the anterior margin of the flap. The superior portion of the flap is innervated by the cutaneous branch of T12 which is located at the superior posterior margin of the flap. This superior portion of the flap is useful if an iliac crest bone graft is incorporated in the free flap (Nahai, 1978, Personal communication).
CASEREPORT A 24-year-old electrical linesman survived an electrical burn and fall. He suffered deep necrosis of the medial aspect of his left leg and the lateral aspect of his right leg. After decortication of his left distal tibia and right fibula, cover of the exposed Achilles tendon and bone was accomplished with skin grafts. The skin graft cover was unstable and required replacement with a flap (Fig. 2A). A TFL free flap transfer has provided the required skin and soft tissue cover (Fig. 2D). Furthermore, a lateral femoral cutaneous nerve has been used in each leg to provide a sensory innervated flap (Fig. 2B). Address for reprints: Stephen J. Mathes, M.D., Division of Plastic and Reconstructive University of California, San Francisco, California 94143, U.S.A. 184
Surgery,
TENSOR
FASCIA
LATA
-TRANSVERSE BRANCH OF LATERAL CIRCUMFC FEMORAL A. -
RECTUS
FEMORIS
-
VASTUS
LATERALIS
SITE OF MUSCLE
IIWISION
_
_
TFL
_
TRANSVERSE
EX
MUSCLE
BRANCH CIRCUMFL _EX
OF LATERAL FEMORAL
A.
__
RECTUS
FEMORIS
--
PEDICCE VASTUS
OF LATERALIS
-
VASTUS
LATERALIS
186
BRITISH
JOURNAL
OF PLASTIC
SURGERY
FIG. I. A. A TFL unit elevated on the left anterolateral thigh of a cadaver to demonstrate location of the vascular nedicle. B. Enlarged view of the lateral femoral circumflex arterv. Note site of division of the TFL to avoid muscle bulk& flap (a vena comitans associated with the arterial pedicle has been excised). C. Sensory innervation for the cutaneous territory of TFL unit. Arrow a denotes location of lateral femoral cutaneous nerve and b denotes location of sensory branch of TIZ.
The left distal leg has decreased sensation as a result of the severe electrical injury. Nine months following the fascicular repair of the lateral femoral cutaneous nerve of this free flap with 4 fascicles of the saphenous nerve, the entire flap demonstrates protective sensation with 2 cm 2 point discrimination in the proximal flap. Cover of the right leg defect with a TFL free flap has recently been accomplished with anastomosis of the lateral femoral cutaneous nerve to the sural nerve. DISCUSSION
With the development of microsurgical free flap transfer, a method of reconstruction in I operation is available for regions where local axial or muscle flaps are not available The distal third of the lower extremity is typical of such a problem area where large defects cannot be covered by local flaps. The value of neurosensory free flap transfer has been demonstrated (Ohmori et al., 1976; Daniel et al., 1976) and could be especially important in lower leg defects. The TFL uuit can provide a large, thin flap with sensory nerves located in the proximal flap where microanastomosis and neural repair can be accomplished simultaneously. The donor defect on the lateral thigh requires skin grafts on the exposed vastus lateralis muscle and has been asymptomatic in our patients. With the proximal muscle left in place, there is minimal contour deformity.
TENSOR FASCIA LATA
‘87
FIG. 2. A. Unstable skin grafts on left medial foot at site of electrical burn. 13. TFL free flap. Arrow denotes location of lateral femoral cutaneous nerve. C. Lateral view of TFL free unit demonstrates thickness of this musculo-cutaneous flap. D. Eight months after successful free transfer of TFL unit by microanastomosis end to end between flap pedicle and posterior tibia1 artery and veins.
SUMMARY A tensor fascia lata musculo-cutaneous free flap has provided reconstruction of a traumatic lower leg defect in I operation. By inclusion of this flap’s sensory nerve, an innervated musculo-cutaneous flap has been designed to satisfy the particular reconstructive requirement in certain areas for a neurosensory free flap.
REFERENCES DANIEL, R., TERZIS, J. and MIDGLEY, R. (1976). Restoration of sensation to an anaesthetic hand by a free neuromuscular flap from the foot. Plastic and Reconstructive Surgery, 573 275. HILL, H., NAHAI, F. and VASCONEZ,L. (1978). The tensor fascia lata rnyocutaneous free flap. Plastic and Reconstructive Surgery, 61, 517. OHMORI, K. and HARRII K. (1976). Free dorsalis pedis sensory flap to the hand with microneurovascular anastomosis. Plastic and Reconstructive Surgery, 58, 546.
TENSOR
FASCIA
LATA:
NEUROSENSORY
MUSCULO-CUTANEOUS
FREE FLAP
By STEPHENJ. MATI-IES, M.D. and ROBERTT. BUCHANAN, M.D. Division of Plastic and Reconstructive Surgery, Washington University, School of Medicine, St Louis, Missouri 63110, U.S.A.
THE tensor fascia lata (TFL) musculo-cutaneous flap has great potential as a flap for microsurgical transfer (Hill et al., 1978). This unit consists of a small antero-lateral thigh muscle, the ilio-tibia1 tract or fascia lata, and their associated cutaneous territory. Although the TFL is small, the distal muscle arterial perforators extend axially along the fascia lata supporting a large cutaneous territory. The cutaneous territory extends from the iliac crest to within 5 cm of the knee centred over the muscle and distal fascia lata (Fig. IA). Furthermore, the unit is thin consisting mainly of fascia lata, subcutaneous fat, and skin (Fig. 2C). Vascular pedicle. The TFL unit is vascularised by the terminal branch of the lateral circumflex femoral artery. This artery is a branch of the profimda femoris and courses beneath the rectus femoris muscle entering the medial anterior belly of the TFL (Fig. IA). With division of the descending branch of the lateral circumflex femoral artery, a long pedicle of 5 to 6 cm may be obtained. The pedicle which enters the muscle IO cm inferior to the anterior superior iliac crest is safely located by medial retraction of the rectus femoris muscle. This artery with associated vein has an external lumen diameter of 1.8 to 2.0 mm. By division of the TFL proximal to the inferior terminal branch of its vascular pedicle, the majority of the muscle is left in place (Fig. IB). This manoeuvre both decreases the bulk of the proximal flap and eliminates a depression in the donor area at the proximal lateral thigh. Sensory nerve. A neurosensory free flap is possible by incorporating the sensory nerves to this unit’s cutaneous territory (Fig. IC). The lateral cutaneous femoral nerve (branch of second and third lumbar nerves) supplies sensation to the distal two-thirds of the cutaneous territory of the TFL unit. The nerve enters the cutaneous territory of the flap IO cm below the anterior superior iliac crest and can be identified at the anterior margin of the flap. The superior portion of the flap is innervated by the cutaneous branch of T12 which is located at the superior posterior margin of the flap. This superior portion of the flap is useful if an iliac crest bone graft is incorporated in the free flap (Nahai, 1978, Personal communication).
CASEREPORT A 24-year-old electrical linesman survived an electrical burn and fall. He suffered deep necrosis of the medial aspect of his left leg and the lateral aspect of his right leg. After decortication of his left distal tibia and right fibula, cover of the exposed Achilles tendon and bone was accomplished with skin grafts. The skin graft cover was unstable and required replacement with a flap (Fig. 2A). A TFL free flap transfer has provided the required skin and soft tissue cover (Fig. 2D). Furthermore, a lateral femoral cutaneous nerve has been used in each leg to provide a sensory innervated flap (Fig. 2B). Address for reprints: Stephen J. Mathes, M.D., Division of Plastic and Reconstructive University of California, San Francisco, California 94143, U.S.A. 184
Surgery,
TENSOR
FASCIA
LATA
-TRANSVERSE BRANCH OF LATERAL CIRCUMFC FEMORAL A. -
RECTUS
FEMORIS
-
VASTUS
LATERALIS
SITE OF MUSCLE
IIWISION
_
_
TFL
_
TRANSVERSE
EX
MUSCLE
BRANCH CIRCUMFL _EX
OF LATERAL FEMORAL
A.
__
RECTUS
FEMORIS
--
PEDICCE VASTUS
OF LATERALIS
-
VASTUS
LATERALIS
186
BRITISH
JOURNAL
OF PLASTIC
SURGERY
FIG. I. A. A TFL unit elevated on the left anterolateral thigh of a cadaver to demonstrate location of the vascular nedicle. B. Enlarged view of the lateral femoral circumflex arterv. Note site of division of the TFL to avoid muscle bulk& flap (a vena comitans associated with the arterial pedicle has been excised). C. Sensory innervation for the cutaneous territory of TFL unit. Arrow a denotes location of lateral femoral cutaneous nerve and b denotes location of sensory branch of TIZ.
The left distal leg has decreased sensation as a result of the severe electrical injury. Nine months following the fascicular repair of the lateral femoral cutaneous nerve of this free flap with 4 fascicles of the saphenous nerve, the entire flap demonstrates protective sensation with 2 cm 2 point discrimination in the proximal flap. Cover of the right leg defect with a TFL free flap has recently been accomplished with anastomosis of the lateral femoral cutaneous nerve to the sural nerve. DISCUSSION
With the development of microsurgical free flap transfer, a method of reconstruction in I operation is available for regions where local axial or muscle flaps are not available The distal third of the lower extremity is typical of such a problem area where large defects cannot be covered by local flaps. The value of neurosensory free flap transfer has been demonstrated (Ohmori et al., 1976; Daniel et al., 1976) and could be especially important in lower leg defects. The TFL uuit can provide a large, thin flap with sensory nerves located in the proximal flap where microanastomosis and neural repair can be accomplished simultaneously. The donor defect on the lateral thigh requires skin grafts on the exposed vastus lateralis muscle and has been asymptomatic in our patients. With the proximal muscle left in place, there is minimal contour deformity.
TENSOR FASCIA LATA
‘87
FIG. 2. A. Unstable skin grafts on left medial foot at site of electrical burn. 13. TFL free flap. Arrow denotes location of lateral femoral cutaneous nerve. C. Lateral view of TFL free unit demonstrates thickness of this musculo-cutaneous flap. D. Eight months after successful free transfer of TFL unit by microanastomosis end to end between flap pedicle and posterior tibia1 artery and veins.
SUMMARY A tensor fascia lata musculo-cutaneous free flap has provided reconstruction of a traumatic lower leg defect in I operation. By inclusion of this flap’s sensory nerve, an innervated musculo-cutaneous flap has been designed to satisfy the particular reconstructive requirement in certain areas for a neurosensory free flap.
REFERENCES DANIEL, R., TERZIS, J. and MIDGLEY, R. (1976). Restoration of sensation to an anaesthetic hand by a free neuromuscular flap from the foot. Plastic and Reconstructive Surgery, 573 275. HILL, H., NAHAI, F. and VASCONEZ,L. (1978). The tensor fascia lata rnyocutaneous free flap. Plastic and Reconstructive Surgery, 61, 517. OHMORI, K. and HARRII K. (1976). Free dorsalis pedis sensory flap to the hand with microneurovascular anastomosis. Plastic and Reconstructive Surgery, 58, 546.
