Keywords Achilles tendon - Composite tissue allografts - Free tissue flaps - Patient outcomes
assessment - Quadriceps muscle
INTRODUCTION
Composite defects involving the Achilles tendon and overlying soft tissue pose a significant
challenge for the reconstructive surgeon. At our institution, the composite anterolateral
thigh (ALT) flap with vascularized fascia lata has become the workhorse for reconstructing
these defects as its versatility, flexibility in skin paddle design, potential for
simultaneous tendon reconstruction, and minimal donor site morbidity, make it ideally
suited for restoring structural integrity to the Achilles region [1 ],[2 ]. Despite these advantages, however, elevation of this flap is occasionally challenged
by the absence or lack of suitable perforators capable of sustaining cutaneous viability
(0.89% to 5.4%) [3 ],[4 ],[5 ],[6 ]. When discovered intraoperatively, a strategy that incorporates nearby tissues derived
from the same source vessel provides a logical alternative for successful reconstruction.
The rectus femoris free flap, in particular, has enjoyed widespread clinical application
including functional restoration of upper and lower extremity defects, facial re-animation,
and dynamic abdominal wall reconstruction [7 ],[8 ],[9 ],[10 ]. However, its role in the reconstruction of combined Achilles tendon/posterior leg
defects has only seldom been reported, and data regarding functional outcomes with
this approach are essentially non-existent. In this report, we describe the composite
rectus femoris/posterior rectus fascial free flap as a rescue alternative for reconstructing
a complex Achilles defect in the setting of insufficient ALT perforators. To our knowledge,
this report represents the first to document the use of a rectus femoris free flap
for this indication.
CASE REPORT
A 74-year-old male sustained complete subcutaneous rupture of the right Achilles tendon
while ballroom dancing. Initial repair via flexor hallucis longus tendon transfer
was performed at an outside institution. The postoperative course was complicated
by progressive, recurrent infection, and the patient subsequently presented to our
clinic after 2 months with a necrotic, infected tendocutaneous defect of the Achilles.
Extensive debridement was performed, on 3 separate occasions, resulting in a 9-cm
tendon gap with an overlying soft tissue defect measuring 90-cm2 ([Fig. 1 ]). Given the extent of the defect, composite tissue transfer utilizing a combined
ALT flap with vascularized fascia lata was proposed.
Fig. 1 Composite tendocutaneous defect of the Achilles
Segmental defect of the Achilles tendon and associated soft tissue deficit following
multiple operative debridements for a failed flexor hallucis longus tendon repair.
The tendon gap at the time of definitive reconstruction measured 9-cm with the overlying
soft tissue defect measuring 90-cm2 . Proximal and distal remnants of the native Achilles tendon can be visualized (yellow
arrows).
Doppler examination in the operating theater revealed a weak, yet audible signal along
the surface of the proposed ALT donor site. Intraoperatively, however, only a single,
small-caliber perforator supplying this region from the lateral circumflex femoral
system could be identified. To avoid the additional morbidity of selecting a surrogate
donor site, a portion of the thinner, more attenuated rectus femoris muscle was harvested
in conjunction with the posterior rectus fascia to reconstruct the soft tissue and
tendoachilles defects, respectively ([Fig. 2A ]). End-to-side microvascular anastomosis was performed between the posterior tibial
artery and the descending branch of the lateral circumflex femoral artery. The fascial
sheet of the composite flap was then rolled into a tendon-like structure and fixed
to the proximal and distal remnants of the Achilles, utilizing multiple permanent,
non-braided sutures ([Fig. 2B, C ]). The donor site was closed primarily over a suction catheter after plication of
the distal extensor mechanism proximal to the patella. A split-thickness skin graft
(0.014 inch) was harvested from the ipsilateral thigh for protective coverage of the
exposed muscle, and the ankle was immobilized in the neutral position with an external
fixation device for 4 weeks ([Fig. 2D ]).
Fig. 2. The rectus femoris myofascial free flap
(A) In situ view of the rectus femoris muscle, prior to flap harvest. Partial retraction of the
muscle allows for visualization of the posterior rectus fascia as well as the muscular
branch to the RF, which is derived from the descending branch of the lateral circumflex
femoral artery. (B, C) Transfer and inset of the rectus femoris myofascial free flap
into the recipient site. The posterior RF fascia is rolled into a neo-tendon construct
and secured to the proximal and distal remnants of the native Achilles tendon (white
arrows) using multiple non-absorbable, non-braided sutures. (D) A split-thickness
skin graft is harvested from the ipsilateral thigh for protective coverage of the
exposed muscle. RF, rectus femoris; AT, Achilles tendon.
Postoperatively, the patient participated in a graduated rehabilitation program characterized
by progression from non-weight bearing range of motion training to pre-gait strengthening
and functional re-education with ultimate return to full activity after six months.
At the final 1-year follow-up, the patient was ambulating well without support and
was able to stand and walk on his tiptoes. He was satisfied with regard to pain, functional
recovery, and cosmetic appearance with excellent healing and an absence of scar adhesion
on clinical exam. Active range of motion of the affected ankle was 53° (17° dorsiflexion,
36° plantar flexion) compared to 62° (20° dorsiflexion, 42° plantar flexion) for the
unaffected side ([Fig. 3 ]). Right hip flexion range and knee extension deficit were 0° to 120° and 0°, respectively,
comparable to the nonoperative side. There was no clinically noticeable deficiency
in quadriceps femoris contraction strength when compared with the contralateral thigh.
American Orthopaedic Foot and Ankle Society (AOFAS) and Short Form-36 (SF-36) scores
at 1 year improved by 78.8% (52 vs. 93) and 28.8% (80 vs. 103), respectively, compared
to preoperative baseline assessments.
Fig. 3. Evaluation at 1-year follow-up
(A) Atrophy and contraction of the muscle flap over time provided for an exceptional
final aesthetic contour. (B, C) Dorsiflexion and plantar flexion of
the composite Achilles construct demonstrating excellent range of motion, postoperatively.
DISCUSSION
With advances in microsurgical technique, composite free tissue transfer has emerged
as the standard for single-stage, functional reconstruction of complex three-dimensional
defects of the distal lower extremity [7 ]. In our experience with combined Achilles defects, we have found the composite ALT
flap with vascularized fascia lata to be a viable alternative for younger, more active
patients whose functional demands often necessitate a more normalized range of motion
with restoration of power and plantar flexion. However, safe elevation of this flap
is occasionally impaired by absent or inadequate perforators supplying the ALT [3 ],[4 ],[5 ],[6 ]. Use of a hand-held Doppler to map out the perforating vessels may help to identify
this situation preoperatively; however, when discovered intraoperatively, alternative
options derived from the same vascular pedicle should be pursued. In this report,
we describe the use of a composite rectus femoris myofascial free flap to reconstruct
a tendocutaneous defect of the Achilles in the setting poorly identifiable ALT perforators.
The rectus femoris, in particular, possesses unique characteristics that make it a
versatile option for composite Achilles defect reconstruction. The muscle itself is
supplied by 1 or more dominant pedicles based on the lateral circumflex femoral artery
and can be elevated as a pedicled or free functional muscle flap, myofascial unit,
or myocutaneous flap depending on the unique reconstructive demand [11 ],[12 ]. When harvested as a free flap in conjunction with the posterior rectus fascia,
segmental defects of the Achilles tendon can be reconstructed, simultaneously, using
a vascularized fascial construct. This obviates the need to recruit additional surrounding
fascia, thereby reducing the complexity of flap dissection as well as the risk of
donor site complications.
From an aesthetic standpoint, atrophy and contraction of the denervated muscle flap,
over time, provided for an exceptional cosmetic result in our patient. Concern over
graft contraction and additional donor site scarring was overcome by harvesting a
slightly thicker skin graft followed by excision and primary closure of the donor
site, respectively. Overall improvement in preoperative symptomatology and level of
function, as well as satisfaction in the aesthetic outcome, appeared to contribute
to the high AOFAS and SF-36 scores observed postoperatively.
Despite its unique advantages and broad applicability, however, controversy regarding
presumed donor site morbidity has precluded widespread use of the rectus femoris flap.
While quantitative studies have shown varying degrees of impairment with respect to
voluntary muscle contraction, true muscular capacity, and range of motion, such as
knee extension and/or hip flexion, the majority of evidence suggests that these limitations
are not clinically significant and are well tolerated by most patients [13 ],[14 ],[15 ]. Daigeler et al. [14 ] analyzed the donor site morbidity of 14 patients who underwent pedicled rectus femoris
muscle flap coverage for a variety of abdominal wall, groin, and proximal thigh defects.
They noted a 21.8% and 18% decrease in maximal voluntary contraction force and true
muscular capacity of the remaining quadriceps femoris, respectively. Despite the significant
loss of force, however, baseline level of function and active range of motion of the
knee and hip were reportedly unaffected. These findings are consistent with those
of Gardetto et al. [15 ] who suggested that harvest of the rectus femoris flap had no clinically significant
donor site morbidity and did not adversely affect the patient's capacity for everyday
activity.
While we did not quantitatively analyze the contractile force or true muscular capacity
of the donor site in this case, full activity was resumed after 6 months without any
noticeable functional deficits, thereby confirming the results of previous studies.
We attribute this in part to our efforts to centralize the remaining quadriceps femoris
by approximating the distal third of the medial and lateral vastus muscles during
closure, which has been suggested to assist in the maintenance of donor site biomechanics
[13 ],[15 ]. Furthermore, we advocate for the incorporation of a structured, graduated rehabilitation
program, postoperatively, which has been shown to improve donor site strength and
stability following harvest of the rectus femoris and is likely a significant contributor
to the excellent functional outcomes and lack of appreciable donor site deficits observed
in this case [14 ],[15 ].
In summary, this report represents the first to describe the composite rectus femoris/posterior
rectus fascial free flap as a rescue alternative for composite Achilles defect reconstruction.
Excellent functional and aesthetic results, high patient satisfaction, and acceptable
donor site morbidity make the rectus femoris myofascial free flap a viable alternative
for functional reconstruction of the Achilles in the setting of inadequate ALT perforators.
As a complement to our reconstructive armamentarium, we now routinely include this
option in our preoperative planning and discussion with our patients.
