The normal functional interaction between the rectus femoris muscle and the hamstrings during gait. There is an eccentric contraction (stretching) of the rectus femoris muscle at the stance-swing phase transition to avoid excessive knee flexion. At the end of swing phase, the rectus femoris muscle is contracted concentrically while the hamstrings are contracted eccentrically. In patients with cerebral palsy, this rapid change in muscular function is impaired. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

The Duncan-Ely test¹⁰. The patient is placed prone on the examination table. Passive knee flexion will activate an increased stretch reflex in the rectus femoris muscle, leading to anterior pelvic tilt and therefore pelvic rise. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

The surgical approach (2 cm in length) for preparation of the rectus femoris tendon, which should be done 2 to 3 cm above the proximal patellar pole. The vertical pink line indicates the later incision of the fascia lata. The black horizontal lines represent the threads for tagging of the fascia lata. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

Illustration showing exposure of the fascia lata and tagging with two number-2-0 Vicryl sutures. This enables later reconstruction. The pink line indicates the resection line of the rectus femoris tendon. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

Photograph showing exposure and tagging of the fascia lata as illustrated in Fig. 4-A.

The rectus femoris tendon is separated from the underlying quadriceps tendon with a clamp. It is important to ensure that only the rectus femoris tendon is released and that the rest of the quadriceps tendon is preserved.

Two anchoring sutures (number-1 Vicryl) are placed in the rectus femoris tendon. The pink line indicates the later resection line for rectus femoris release. (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

The tagged rectus femoris tendon is released as distally as possible without injuring the underlying quadriceps tendon.

Illustration showing the rectus femoris muscle carefully mobilized from the underlying quadriceps by digital preparation. The palpating finger slips smoothly between the rectus femoris muscle and the underlying quadriceps. The pink line indicates the later resection line for the rectus femoris release. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

Photograph showing the rectus femoris muscle mobilized from the underlying quadriceps, as illustrated in Fig. 7-A.

The rectus femoris tendon is freed from the encompassing tissue with use of the scissors.

It is very important to dissect the medial fascia lata enough to avoid a later angular deviation of the transferred rectus femoris tendon at the incision site.

The released rectus femoris tendon undersurface is shown. It is important to check if just the rectus femoris tendon was released. At the undersurface, the rectus femoris tendon is normally covered by a thin sheath, indicating that this is the correct layer.

The anatomy of the medial aspect of the thigh. Anatomical structures should be considered when performing the medial approach for the preparation of the gracilis or semitendinosus tendon. (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

After incision of the fascia, the gracilis muscle belly can be exposed by the use of one finger or with a clamp.

Illustration showing how the intramuscular tendon of the gracilis is explored and separated from the underlying muscle belly with use of scissors. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

Photograph showing exploration and separation of the intramuscular tendon of the gracilis, as illustrated in Fig. 11-A.

The tendon is then followed as proximally as possible to obtain an adequate tendon length for the transfer.

After separation of the tendon from its muscle belly, anchoring sutures (number-1 Vicryl) are placed in the tendon as proximally as possible. (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

After the gracilis tendon is released proximally to the tagging suture, the knee is fully flexed and the gracilis tendon is separated from the muscle belly as distally as possible.

The tendon is freed from all remaining muscle tissue in order to guarantee a smooth transfer.

The mini-incision for pulling out the gracilis tendon is made 1 to 2 cm above the pes anserinus (pink line). The gracilis tendon can be identified during palpation of the distal part of the tendon at the pes anserinus while the assistant tensions the gracilis by pulling at the tagging sutures proximally. (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

After the incision, the tendon sheath of the gracilis tendon is opened and the gracilis tendon is exposed with a clamp.

Illustration showing how the gracilis tendon is pulled out with use of a moist sponge. (Reproduced, with permission of Springer Science+Business Media, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22.)

Photograph showing the gracilis tendon pulled out with a moist sponge, as illustrated in Fig. 16-B. Again, the surgeon should check if the tendon is long enough for the transfer.

Through a distal medial incision above the palpable gracilis tendon, a small incision (standard approach for distal z-lengthening or sliding of medal hamstrings) is made and the tendon sheath of the gracilis tendon is opened to expose the tendon.

A tendon harvest instrument is used, and the tendon is merged.

The tendon harvester is then driven proximally by palpating with the other hand.

A cutting mechanism is used, and the tendon is pulled out distally afterward. (Figs. 17-A through 17-D show the standard technique for gracilis harvesting used by Dr. Walter Strobl, pediatric neuro-orthopaedic surgeon from the Paediatric Orthopaedic Hospital Speising in Vienna, Austria.)

Through the initial anterior approach, the transfer path is prepared by medial epifascial tunneling toward the approach in the popliteal fossa. For the tendon transfer, a long clamp is then inserted above the fascia and below the sartorius muscle belly to the mini-incision in the popliteal fossa. (For the reason of simplification in visualization, the rest of the quadriceps is not shown.) (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

Photograph showing the technique illustrated in Fig. 18-A.

The tagging sutures of the released gracilis tendon are grasped, and the gracilis tendon is then transferred behind the knee axis of rotation to the anterior wound.

With the transfer clamp, the gracilis tendon is weaved in the released rectus femoris tendon with the interlacing technique described by Pulvertaft¹⁴ under moderate tension with use of number-1 Vicryl suture, while the leg is positioned in 20° to 30° of knee flexion on the roll.

Illustration showing the technique described in Fig. 19-A. (For the reason of simplification in visualization, the rest of the quadriceps is not shown.) (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

Alternative technique for transfer of the rectus femoris tendon to the iliotibial band, which is indicated when a hamstring lengthening was previously done. The same technique is used to prepare the rectus femoris tendon (Steps 1 and 2). It is important to release the rectus femoris tendon especially laterally when a lateral transfer is done. A lateral approach is performed at the lateral aspect of the distal part of the thigh. After the dissection of subcutaneous tissue, the iliotibial band is exposed. A small (1-cm) incision is made, and the transfer clamp is inserted through this incision to the anterior approach, where the tagging threads of the rectus femoris tendon are grabbed. Then the rectus femoris tendon is pulled laterally and weaved and stitched in the iliotibial band with use of the Pulvertaft technique¹⁴. (Reproduced, with modification, from: Wenz W, Döderlein L. Die Verpflanzung der Sehne des Musculus rectus femoris bei Patienten mit spastischer Diparese. Oper Orthop Traumatol. 1999;11[3]:213-22. Reproduced with permission of Springer Science+Business Media.)

Preoperative sagittal plane knee kinematics of a patient with stiff-knee gait, characterized by decreased peak knee flexion in swing, decreased knee flexion velocity, decreased knee flexion in swing, and a delay in peak knee flexion in swing. The dashed line represents the right limb and the solid line represents the left limb. The gray area represents reference data for physiologic knee kinematics obtained from a group of twenty-five normal subjects. Positive values indicate knee flexion.

Preoperative sagittal plane knee kinematics of another patient with stiff-knee gait, characterized by decreased peak knee flexion in swing, decreased knee flexion velocity, decreased knee flexion in swing, and a delay in peak knee flexion in swing. The dashed line represents the right limb and the solid line represents the left limb. The gray area represents reference data for physiologic knee kinematics obtained from a group of twenty-five normal subjects. Positive values indicate knee flexion.

Preoperative sagittal plane knee kinematics of a patient with severe flexed-knee gait throughout the stance and swing phases, reaching normal and even increased peak knee flexion in swing. The dashed line represents the right limb and the solid line represents the left limb. The gray area represents reference data for physiologic knee kinematics obtained from a group of twenty-five normal subjects. Positive values indicate knee flexion.

Preoperative sagittal plane knee kinematics of another patient with severe flexed-knee gait throughout the stance and swing phases, reaching normal and even increased peak knee flexion in swing. The dashed line represents the right limb and the solid line represents the left limb. The gray area represents reference data for physiologic knee kinematics obtained from a group of twenty-five normal subjects. Positive values indicate knee flexion.

Preoperative sagittal plane knee kinematics of a patient with jump-knee gait¹¹. Both limbs show increased knee flexion at initial contact and normal or slightly increased knee extension during stance phase, which is characteristic of jump-knee gait. While the left limb reaches almost normal peak knee flexion in swing, the right limb shows relevantly decreased peak knee flexion in swing. The dashed line represents the right limb and the solid line represents the left limb. The gray area represents reference data for physiologic knee kinematics obtained from a group of twenty-five normal subjects. Positive values indicate knee flexion.