PMC8650671_01
(a) Preoperative lateral knee radiograph showing the absence of osseous pathology with patella baja compatible with a quadriceps rupture. (b) Preoperative sagittal magnetic resonance imaging section showing massive retracted quadriceps rupture.
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Radiographs showed no osseous pathology (Figure 1a). Magnetic resonance imaging (MRI) confirmed a rupture with a substantial gap at the mid-tendon-musculotendinous junction of quadriceps muscle which was suspected to occur through the failure of previous quadriceps repair (Figure 1b). 
Intraoperative view of the surgical area. (a) Before the operation. (b) Identification of rupture. (c) Final intraoperative view showing upper layer of the allograft. Both layers were sutured to adjacent tissues.
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Under spinal anesthesia, a 15-cm longitudinal incision medial to previous surgical incision was performed over the right knee from the superior pole of the patella (Figure 2a). The proximal and distal portions of rupture were identified (Figure 2b, c). Finally, the graft was sutured primarily to the adjacent tissue (Figure 2c). 
Representative drawing of the technique. (a) Suture configuration after placement of allograft. (b) Final view after placement of suture anchors to the superomedial side of the patella.
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Graft reconstruction was made by the end-to-end repair using the Krackow technique with No. 2 non-absorbable braided sutures (Ethibond ; Ethicon Inc., Somerville, NJ, USA) to maintain construct stability along with the graft (Figure 3a). The Krackow suture's limbs were pulled distally and tied with the sutures of anchors on the allograft using surgical knot (Figure 3b).
Postoperative control MRI at six years of follow-up. (a) Sagittal MRI. (b) Anteroposterior and (c) lateral radiographs of the knee. Graft incorporation is evident. The patient had patella baja not interfering with physical activities.
MRI: Magnetic resonance imaging.
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Six years after surgery, control MRI showed graft incorporation (Figure 4a). Control X-ray demonstrated patella baja deformity (Figure 4b); however, the patient had 135 degrees of flexion and less than 10 degrees of extension, compared to the healthy side (Figure 5a, b).
Physical examination at last follow-up. (a) Single leg raise. (b) 135 degrees of flexion. (c) Double leg squat and (d) semi-squat position.
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Control X-ray demonstrated patella baja deformity (Figure 4b); however, the patient had 135 degrees of flexion and less than 10 degrees of extension, compared to the healthy side (Figure 5a, b). He was able to do a double-leg semi-squat at 135 degrees of flexion (Figure 5c-d).