Poster Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

Prevention for cage retropulsion following posterior lumbar interbody fusion (#7)

Hiroyuki Aono 1 , Shota Takenaka 2 , Yukitaka Nagamoto 3 , Hidekazu Tobimatsu 4 , Masayuki Furuya 5 , Tomoya Yamashita 1 , Hiroyuki Ishiguro 1 , Atsunori Ohnishi 1 , Motoki Iwasaki 3
  1. Osaka National Hospital, Osaka, OSAKA, Japan
  2. Orthopedic Surgery, JCHO Osaka Hospital, Osaka
  3. Orthopedic Surgery, Osaka Rosai Hospital, Sakai
  4. Orthopedic Surgery, Bell Land General Hospital, Sakai
  5. Orthopedic Surgery, Osaka University Hospital, Suita

6552f6fa1aa11-ISSLS2024.jpgINTRODUCTION: Cage retropulsion after posterior lumbar interbody fusion (PLIF) is relatively rare, but serious complication, as once it occurred, revision surgery is required in many cases. We investigated cage retropulsion after PLIF preformed for patients with degenerative lumbar diseases in one institution with seme surgical methodology.

METHODS: We retrospectively reviewed the surgical database providing prospectively collected details of all spine operations between June 2006 and September 2022 at our institution. During that period, we performed PLIF to treat 946 consecutive patients with degenerative lumbar diseases. We excluded patients within 1-year follow up and deep surgical site infection. All PLIF procedure were performed using the same techniques. In summary, our techniques consisted of bilateral facetectomy; subtotal discectomy; a large amount of local bone graft (at least 2 strut bone blocks with 2 box-type cages) and pedicle screw instrumentation.

Cage retropulsion was defined as the movement of the posterior margin of the cage into the spinal canal by lateral radiographs at latest follow up. We also evaluated age at surgery, gender, and number of PLIF segment.

RESULTS: Nine hundred and eighteen patients were enrolled in this study (follow up rate 97%). There were 342 male and 576 female with mean age at surgery 71. Total number of PLIF segments was 1038 (one-level: 803, two-level: 110, 3-level: 5). Eighty-seven PLIF were performed to treat adjacent segment disease after PLIF. We had no patients with cage retropulsion.

DISCUSSION: Incidence of cage retropulsion after PLIF/TILIF is reported 0.8-4.7％, and risk factors are older age, high BMI, multi-level fixation, size and shape of cages, endplate injury, and shape of disc space in previous reports. We believe through discectomy and large amount of bone graft contributed no cage retropulsion in our series. In conclusion, we checked cage retropulsion after PLIF and had no case of cage retropulsion. We may be able to prevent cage retropulsion by thorough bone graft to disc space.