case_images: PMC6457017_01
case_images: Preoperative macroscopic findings: (a) Injury scar immediately proximal to
  the metatarsophalangeal joint (arrow), (b) distal and proximal extensor
  hallucis longus stumps (arrow heads) and (c) insufficient extension of
  metatarsophalangeal and interphalangeal joints of the hallux.
case_images: 10.1177_2050313X19841962-fig1.jpg
case_images: PMC6457017_01_10.1177_2050313X19841962-fig1.jpg
case_images: fig1-2050313X19841962
case_images: An EHL tendon rupture was suspected (Figure 1).
case_images: Preoperative magnetic resonance imaging (MRI) findings. Sagittal T2-weighted
  MRI revealed the loosening of the extensor hallucis longus tendon (arrow).
  Extensor hallucis capsularis was not evaluated in the forefoot and midfoot
  areas because of inappropriate MRI scan area.
case_images: 10.1177_2050313X19841962-fig2.jpg
case_images: PMC6457017_01_10.1177_2050313X19841962-fig2.jpg
case_images: fig2-2050313X19841962
case_images: Magnetic resonance imaging (MRI) revealed the loosening of the EHL tendon (Figure 2).
case_images: Preoperative computed tomography (CT) image findings. Coronal CT images
  revealed the extensor hallucis capsularis (EHC) (arrow heads) medial to the
  proximal stump of the extensor hallucis longus (EHL) tendon (arrow). The
  width and thickness of EHC were approximately 3 and 2 mm, respectively. The
  EHC tendon separated from the EHL tendon distal to the tarsometatarsal joint
  and travelled alongside. Preoperatively, this was considered the point of
  divergence of the EHC and EHL, but it was the adhesion intraoperatively.
case_images: 10.1177_2050313X19841962-fig3.jpg
case_images: PMC6457017_01_10.1177_2050313X19841962-fig3.jpg
case_images: fig3-2050313X19841962
case_images: Computed tomography (CT) images revealed the presence of an EHC tendon medial to the proximal stump of the EHL tendon (Figure 3).
case_images: Intraoperative findings: (a) The proximal and distal extensor hallucis longus
  (EHL) stumps (asterisks) following the incision of the tendon sheath and the
  distal part of the inferior extensor retinaculum (solid lines). The gap
  between stumps was 5 cm. Thick extensor hallucis capsularis (EHC) (dotted
  line) was found medial to the EHL. The extensor hallucis brevis was intact
  (X). (b) Retrieved EHL (dotted line) and EHC (solid line) at the proximal
  wound. EHC arising from the distal end of the EHL muscle adhered to the EHL
  tendon (asterisk). (c) EHC (solid line) was resected from its origin and
  turned down at the point of adhesion to EHL (dotted line). (d) A
  double-bundle EHC autograft was sutured to the distal EHL stump in an
  interlacing manner. The double-bundle graft of EHC was slightly thinner than
  that of EHL; however, if we used a turn-down reconstruction of EHL, it must
  have been thinner than the double-bundle graft. Schematic diagram shows the
  design of the double-bundle EHC autograft for EHL reconstruction. (e) The
  first metatarsophalangeal and interphalangeal joints were slightly flexed at
  ankle dorsiflexion and slightly extended at ankle plantarflexion following
  suturing.
case_images: 10.1177_2050313X19841962-fig4.jpg
case_images: PMC6457017_01_10.1177_2050313X19841962-fig4.jpg
case_images: fig4-2050313X19841962
case_images: The gap between the stumps was 5 cm at that time (Figure 4(a)). The EHL tendon was pulled distally in the proximal wound, which revealed that the EHC arose from the distal end of the EHL muscle and adhered to the EHL tendon under the portion of the inferior retinaculum (Figure 4(b)). Therefore, it was resected from its origin and turned down at the point of adhesion to the EHL (Figure 4(c)). Thereafter, the EHC was sutured alongside as a double-bundle autograft (Figure 4(d)). The sutures were carefully placed in a manner that the first MTP and interphalangeal (IP) joints were slightly flexed at ankle dorsiflexion and slightly extended at ankle plantarflexion (Figure 4(e)).
case_images: Postoperative macroscopic findings. The active range of dorsiflexion of the
  hallux 1 year after surgery.
case_images: 10.1177_2050313X19841962-fig5.jpg
case_images: PMC6457017_01_10.1177_2050313X19841962-fig5.jpg
case_images: fig5-2050313X19841962
case_images: ROM was slightly decreased (Figure 5).