The rectus femoris tendon is emerging as a reliable autograft option for knee ligament reconstruction, and a recent cadaveric study now provides surgeons with precise anatomical landmarks to harvest it safely and reproducibly.
The information presented in this article is drawn from a comprehensive peer-reviewed study titled Rectus femoris tendon morphometry and practical landmarks for harvesting: A cadaveric study, published in Knee Surgery, Sports Traumatology, Arthroscopy (2025) by Pr. Etienne Cavaignac and his peers. This research team dissected ten fresh-frozen cadavers to map the tendon’s dimensions, its fusion zones within the quadriceps tendon, and the practical steps needed for a safe harvest. What follows is a clear, accessible summary of their findings and what they mean for patients and practitioners.
Where is the rectus femoris tendon located within the quadriceps tendon?
Understanding the quadriceps tendon superficial layer rectus femoris anatomy is the first step toward understanding why this graft is attracting attention.
The quadriceps tendon (the thick fibrous band that connects the four quadriceps muscles to the kneecap) is not a single uniform structure. It is organised in layers. The rectus femoris (RF) tendon forms the most superficial layer, meaning it sits on top of the deeper contributions from the vastus intermedius, vastus medialis and vastus lateralis.
In the study, this layered architecture was consistent across all ten specimens. The RF tendon originates from the anterior inferior iliac spine (a bony prominence at the front of the pelvis), runs along the front of the thigh, and integrates into the quadriceps tendon above the kneecap. Its distal fibres follow an oblique course, running from medial-distal to lateral-proximal relative to the femoral shaft.
Two constant fusion zones were identified:
- A distal confluence located on average 22.4 mm above the upper pole of the patella (kneecap), where the superficial RF layer fuses with the deeper quadriceps layers.
- A proximal confluence located on average 58.5 mm above the patella, where the superficial layer again joins the deeper aponeurotic fibres.
Between these two points lies a segment of approximately 36 mm that is entirely free of deep attachments. This “free segment” is what makes the tendon distinguishable, isolatable and harvestable.
What are the safe landmarks for rectus femoris tendon harvesting?
The study’s most practical contribution is the definition of a safe rectus femoris tendon harvest corridor. Based on the rectus femoris tendon harvesting anatomical landmarks identified in all specimens, the authors recommend the following approach.
The skin incision (3 to 4 cm long) should be centred over the free segment, between 22 and 58 mm above the upper pole of the kneecap. Within this window, the superficial tendon flap has no connections to the deep layers, allowing direct access to the RF.
Once the incision is made, two parallel cuts approximately 1 cm apart are placed on the superficial lamina, slightly more than 2 mm deep, oriented obliquely from medial-distal to lateral-proximal. A 7 mm closed tendon harvester is then advanced along this oblique trajectory toward the anterior inferior iliac spine.
A simple operative check confirms the dissection is in the correct plane: at the proximal fusion zone, the surgeon should be able to separate the superficial and deep layers with a finger. If digital separation is not possible, the dissection plane is incorrect and must be redirected before the harvester is introduced. This tactile verification reduces the risk of lacerations or premature graft detachment.
This rectus femoris tendon harvest technique for knee ligament reconstruction was reproducible across every specimen in the study, yielding intact grafts each time.
Rectus femoris tendon dimensions for ligament reconstruction
One of the key questions surgeons face when considering any graft option is: are the dimensions sufficient? The study provides detailed measurements that confirm the rectus femoris tendon graft diameter and usable length meet clinical requirements.
The mean tendon length was 300.8 mm (range: 260 to 340 mm). Its width increased from 20.1 mm at 5 cm above the patella to 47.0 mm at 20 cm, giving it a triangular shape. Thickness followed the opposite pattern: 2.1 mm distally (at 5 cm) and 0.6 mm at 20 cm.
When a 1 cm wide strip was harvested and folded, the graft produced the following configurations:
| Configuration | Mean diameter | Mean usable length |
| Double-strand | 8.8 mm | 151.2 mm |
| Triple-strand | 9.9 mm | 98.5 mm |
| Quadruple-strand | 11.4 mm | 74.0 mm |
So, what graft diameter can be achieved with a rectus femoris tendon autograft? A double-strand construct already reaches approximately 8.8 mm, a size considered adequate for many ACL surgeries. For procedures requiring a thicker graft, such as posterior cruciate ligament reconstruction, triple or quadruple folding can achieve diameters above 10 mm.
Is the rectus femoris tendon suitable for ACL and revision reconstruction?
The data strongly supports the use of a rectus femoris tendon autograft for ACL reconstruction, including primary, revision and multiligament procedures.
Several features make this graft particularly versatile. Its length (averaging 30 cm) is sufficient to perform combined procedures with a single tendon, such as ACL reconstruction paired with a lateral extra-articular procedure (LEAP), or ACL combined with anterolateral ligament reconstruction. This makes the rectus femoris tendon graft for revision ACL surgery especially relevant, since revision cases often require longer grafts or combined approaches.
Unlike hamstring tendon grafts, harvesting the RF preserves both hamstring tendons. This maintains dynamic valgus restraint (the hamstrings’ role in stabilising the knee against inward forces), which is particularly advantageous in cases involving combined ACL and medial collateral ligament injuries. The RF harvest also avoids the anteromedial tibial incision associated with hamstring harvesting, eliminating the risk of saphenous nerve sensory disturbance.
Because only the superficial layer is harvested, the deeper quadriceps fibres remain intact. Traditional full-thickness quadriceps tendon harvesting has been linked to anterior knee pain and extensor mechanism weakness. Harvesting only the RF component may reduce these risks. Early clinical evidence from revision ACL cases shows that isolated RF autografts achieve four-strand diameters around 9 mm, with improved postoperative stability and low donor-site morbidity. Patient-reported outcomes at short-term follow-up have been comparable to hamstring autografts, with similar failure rates.
Conclusion & Findings
This cadaveric study provides the surgical community with a detailed, reproducible roadmap for rectus femoris tendon harvesting. By defining two constant fusion zones and a free segment between them, it establishes clear landmarks that can guide both experienced and training surgeons toward a safe, efficient harvest.
For those interested in exploring the broader body of research behind these advances in knee ligament reconstruction, we encourage reading the other scientific studies by Pr. Etienne Cavaignac and his collaborators, which cover topics ranging from anterolateral ligament reconstruction to graft selection and surgical technique innovation.