case_images: PMC9894634_01
case_images: Clinical images showing a) knee recurvatum compensated by extension of the hip and dorsiflexion of the foot. b) Significant recurvatum in the supine position of the left knee, c) recurvatum of the right knee, and d) 3 cm shortening.
case_images: cureus-0015-00000033317-i01.jpg
case_images: PMC9894634_01_cureus-0015-00000033317-i01.jpg
case_images: FIG1
case_images: On physical examination, the patient has bilateral valgus and bilateral knee recurvatum of 40 , a shortening of 3 cm of the left lower limb (Figure 1). The last follow-up X-rays showed good positioning of the TKA for both knees with no signs of prosthetic loosening (Figure 5 and Table 1).
case_images: Frontal (a) and lateral (b) preoperative X-ray showing severe valgus knee with patella baja for both knees.
case_images: cureus-0015-00000033317-i02.jpg
case_images: PMC9894634_01_cureus-0015-00000033317-i02.jpg
case_images: FIG2
case_images: An X-ray of both knees revealed a bilateral tricompartmental gonarthrosis, with a bilateral valgus (15  for the left knee and 13  for the right knee) and patella baja for both knees (Figure 2).
case_images: a) Intraoperative view showing the Z-plasty for the patellar tendon. b) Intraoperative view after femoral and tibial cuts with denervation of the patella. c,d) Intraoperative view showing the knee prosthesis and lengthening of the extensor apparatus by Z-plasty and reinforcement by a supra-patellar framing by the medial rectus.
case_images: cureus-0015-00000033317-i03.jpg
case_images: PMC9894634_01_cureus-0015-00000033317-i03.jpg
case_images: FIG3
case_images: A patellar tendon Z-plasty was performed to dislocate the patella and correct the patella baja (Figure 3a). After realization of distal femoral cuts, anterior, posterior, and anteroposterior chamfer with 5  of hip-knee-shaft angle (HKS), 0  of rotation for the two knees, we preserved a recurvatum of 9  for both knees, and then the realization of patellar denervation (Figure 3b). Next, lengthening of the extensor apparatus by Z-plasty and reinforcement by a supra-patellar framing by the medial rectus were done (Figures 3c-3d].
case_images: Functional results at the last follow-up. a) Patient with 9  of right knee recurvatum; b) patient with 85  of right knee flexion; and c) patient with 70  of left knee flexion.
case_images: cureus-0015-00000033317-i04.jpg
case_images: PMC9894634_01_cureus-0015-00000033317-i04.jpg
case_images: FIG4
case_images: The patient gained a range of motion of 9-90 after six months (Figure 4).
case_images: Lateral (a) and frontal (b) views of six months postoperative X-ray showing good alignment with no signs of loosening.
case_images: cureus-0015-00000033317-i05.jpg
case_images: PMC9894634_01_cureus-0015-00000033317-i05.jpg
case_images: FIG5
case_images: The last follow-up X-rays showed good positioning of the TKA for both knees with no signs of prosthetic loosening (Figure 5 and Table 1).