It is not uncommon to have to resect one or more components of the four quadriceps muscles during sarcoma resection from the anterior compartment of the thigh[
At our institution, in the setting of anterior compartment resections of the thigh for malignant soft tissue tumors, we do not routinely proceed with functional reconstruction or augmentation of the quadriceps muscles if at least one of the four quadriceps muscle groups remain intact. In those patients who undergo complete resection or complete loss of continuity (central wide resections) and/or denervation of all four quadriceps, we have been successful in restoring essential quadriceps function utilizing a single gracilis muscle transfer, either as a free flap from the contralateral leg, or, more recently, as a simple pedicled gracilis muscle from the ipsilateral leg. With either technique, the gracilis muscle is transferred into the rectus femoris position. With training, the gracilis is able to hypertrophy enough to perform essential quadriceps function.
Institutional research ethics approval was obtained for the study (Ethics #: HS23291). We retrospectively reviewed all patients at our institution who underwent complete resection and/or had complete denervation of all four quadriceps muscles as part of their sarcoma resection of the anterior thigh and reconstruction with a single gracilis muscle. All cases were performed by a single surgeon (Hayakawa TEJ). Patient demographics, surgical technique, and clinical outcomes such as British Medical Research Council (MRC) grading, knee extension, and ambulatory status is reported.
The choice of free or pedicled gracilis is usually determined by the degree of cutaneous soft tissue reconstruction required. If there is a relatively small cutaneous defect, then both the functional quadriceps reconstruction and soft tissue reconstruction are accomplished by a single free contralateral gracilis myocutaneous flap. If the soft tissue or skin defect is too large for the gracilis skin paddle, then an ipsilateral pedicled gracilis is transferred into the rectus femoris position for the functional component of the reconstruction, and a larger cutaneous free tissue transfer such as an anterolateral thigh (ALT) or deep inferior epigastric perforator (DIEP) flap is added for coverage of the soft tissue defect.
In both scenarios, the inset of the gracilis is identical, and into the rectus femoris position. The gracilis will become the only “quadriceps” muscle and will provide both hip flexion and knee extension, which are both essential for normal gait. The entire length of the gracilis is harvested as previously described[
When performing an ipsilateral pedicled gracilis, the vascular pedicle is dissected and freed to the profunda femoris artery and vein beneath the adductor longus. The “tunnel”, deep to the adductor longus and superficial to the adductor brevis and magnus, may need to be elongated by making a “slit” or cut in the upper border of adductor longus that it is long enough to allow the gracilis muscle to be passed through from its normal position on the medial side of abductor longus to its new position on the lateral side. Care is taken to ensure there is no pressure or kinking of the gracilis vascular pedicle, which now must curve or arc up and over the profunda vessels as it follows the muscle during its transfer from the medial to the lateral side of the abductor longus. The gracilis is then placed into the rectus femoris position [
A: Pedicled gracilis harvest post-resection. Note the adductor longus releasing incision to prevent pedicle kinking following flap transposition allowing for tension-free inset; B: Gracilis inset in position of rectus femoris; C: Skin defect was covered with free anterolateral thigh flap
Artist rendition of surgical technique
During flap harvest, we transect the motor branch of the obturator nerve to the gracilis and perform a neurorrhaphy to the most suitable available motor branch stump of the femoral nerve, which is ideally the remaining stump of the motor branch to the rectus femoris
Neurorrhaphy of motor branch of obturator nerve to motor nerve of rectus femoris
The post-operative protocol consists of a five-day hospital stay to ensure flap viability and to educate patients in transfers in and out of a wheelchair. A ZimmerTM (Zimmer Biomet Holdings Inc. Warsaw, IN, USA) knee extension splint is fitted on the final hospital day with the knee in full extension. The patients are maintained in a wheelchair for two weeks post-operation to optimize wound healing and prevent seroma formation. At six weeks, the patients are switched from the Zimmer splint to an adjustable hinged knee splint and begin range of motion exercises that increase by 20° increments every week. Simultaneously motor frequency transcutaneous electrical nerve stimulation is begun. As soon as MRC grade 1 contraction is identified (a flicker of muscle contraction), the patients begin quadriceps strengthening exercises. Many standard strengthening techniques cannot be used because the knee is unstable from lack of quadriceps tone and therefore the ones shown in
Quadriceps strengthening exercises post-reconstruction
We performed a gracilis muscle transfer to replace total quadriceps function in four patients with large central sarcoma resections resulting in large central gaps and/or denervation of all four quadriceps muscles. Patient’s age at the time of surgery ranged from 24 to 65 years. Follow up in the three patients still alive ranged 3-20 years, with the single deceased patient surviving under three months following surgery and dying as a result of metastatic disease. All patients had high grade sarcomas, Fédération Nationale des Centres de Lutte Contre le Cancer Grade 3, and all surviving patients had negative margins at the time of initial resection. No patients had metastasis at the time of surgery. Two of the three patients continue to survive despite metastatic disease that occurred at three years following initial treatment in one, and eight years in the other. Both have pulmonary metastatic disease, and both have undergone treatment for their metastasis, one in the form of Video-Assisted Thoracoscopic Surgery and the other by Stereotactic Body Radiation Therapy. All patients underwent neoadjuvant radiation prior to surgery, and none of the surviving patients received chemotherapy. The reconstructions following resection included a free functional gracilis myocutaneous flap in one patient, a pedicled gracilis combined with an ALT flap in 2 patients, and a pedicled gracilis with a deep inferior epigastric artery perforator/superficial inferior epigastric artery (DIEP/SIEA) in one patient. The 3 surviving patients achieved MRC grade 4 muscle strength and were able to achieve full knee extension 12-18 months post-operation. The three surviving patients are able to ambulate without a brace and rise from the sitting position. All three of these patients demonstrated clinical signs of re-innervation with palpable muscle contraction beginning at, or just after 3 months post-operatively. Due to the clinical return of function, no electrophysiologic studies were performed. The exact length of the obturator nerve to the gracilis was not recorded, but in every case it was cut as short as possible to reduce re-innervation time yet still allow a tension free neurorrhaphy. One patient died from his disease less than three months post-operation, and therefore it was too early to demonstrate any contraction in the reinnervated functional reconstruction.
The first case demonstrates a 50-year-old female with complete central resection of all four quadriceps
Post-oncologic resection of rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius in a patient with a large high-grade sarcoma
Grade 4 muscle strength at one year: extension of leg against gravity and resistance
Her anticipated progress is demonstrated in the following videos. MRC grade 1 strength with contraction is noted at three months post-operation
MRI showing right gracilis muscle hypertrophy post functional muscle transfer: (A) pre-operative MRI; and (B) 12-month post-operative MRI. MRI: magnetic resonance imaging
The second patient is a 22-year-old female with a large central resection of all four quadriceps muscles of left leg, reconstructed with a free gracilis muscle.
Demonstration of leg extension after free functional gracilis muscle flap to left quadriceps position at three years post-surgery: (A) leg at rest; (B) full active extension of leg; and (C) skin paddle of flap
An MRI at three years post-surgery again shows that hypertrophy of the transferred gracilis muscle has occurred
MRI showing gracilis muscle hypertrophy post free functional gracilis to left leg: (A) pre-operative MRI; and (B) 36-month post-operative MRI. MRI: magnetic resonance imaging
Although the anterior compartment of the thigh is the most common location for soft tissue sarcomas, complete resection of all four quadriceps muscles is uncommon[
It has been our past practice not to proceed with functional reconstructions in those patients having at least one of the four quadriceps muscles remaining following tumor resection. Although these patients may be somewhat initially disabled, we noticed that with training and physiotherapy most are able to achieve unassisted ambulation, normal to near normal appearing gait, and full or nearly full knee joint extension. These findings are likely due at least in part to the well-established observation in both bodybuilding and powerlifting that muscles have the capacity for hypertrophy[
From a surgical perspective, the gracilis is a simple, straight forward transfer, particularly if it is pedicled. The gracilis is in the same surgical field as the resection and hence there is no additional donor site morbidity, and no change of positioning or awkward positioning is required. The gracilis flap can be pedicled into the defect with no ischemia time and no microvascular anastomosis. The stout proximal fascia and long distal tendon make the gracilis perfectly suited for insertion into the rectus femoris origin proximally and into the quadriceps tendons distally with a strong Pulvertaft weave. The obturator nerve can be cut short for more rapid reinnervation if a long femoral nerve stump exists or tailored to be longer if the nerve was involved with the tumor more proximally. Thus far, we have always reinnervated the gracilis with the rectus femoris motor nerve branch of the femoral nerve, which is tagged during resection. Failure of reinnervation has not been a problem. Although not performed for sarcoma surgery, we have successfully performed pedicled functional gracilis leaving the obturator nerve to gracilis intact. We have utilized this in combination with a nerve transfer for complete femoral nerve injuries. In this case, the muscle dissection and placement are the same, but the obturator branch to the gracilis is left intact and the gracilis is “piggybacked” onto the medial side of rectus femoris. In this case, the obturator branch to the adductor longus is transected and used as a simultaneous nerve transfer to reinnervate the rectus femoris. Therefore, simply leaving the motor nerve to the gracilis intact during pedicled gracilis transfer may be another technique option but we do not have experience utilizing this in our sarcoma reconstructions.
There are advantages to the gracilis over the other free muscle transfers: its donor site functional deficit is likely less than that of a rectus abdominis, latissimus dorsi, or contralateral rectus femoris, and the recipient vessel location or the necessity of vein grafts in a radiated vessel depleted field does not become a factor when trying to accurately position the pedicled muscle transfer as compared to a free tissue transfer.
There are certainly situations in which other muscle transfers should be considered. For example, if the resection necessitates a femoral prosthesis, a latissimus dorsi or rectus abdominus is probably better suited to provide more complete coverage of the prosthesis. If the sartorius remains following resection, then it should also be considered in addition to the gracilis as described by Willcox
We choose to place the gracilis in the rectus femoris position for several reasons. The ability to stand from a seated position is one of the most important measures of physical function and is essential for independent living[
In summary, the required amount of quadriceps strength necessary to maintain quality of life has not been accurately established[
Concept study design, literature search, and manuscript writing: Hayakawa TEJ
Manuscript preparation, data acquisition: Nguyen CM, Ratanshi I
Manuscript review: Giuffre JL, Buchel EW
IRB approved retrospective study based on University of Manitoba Health Sciences Centre hospital charted data.
None.
All authors declared that there are no conflicts of interest.
IRB approval prior to data acquisition and study design (HS23291).
A written informed consent for publication of videos and photos were obtained.
© The Author(s) 2019.