Scholarlink

Background <p>Inadequate restoration of L4-S1 segmental lordosis (SL) is a recognized contributor to adjacent segment disease (ASD). However, evidence regarding its impact on long-term revision rates remains conflicting, primarily due to short follow-up periods that fail to capture the critical transition from radiographic degeneration to symptomatic disease.</p> Purpose <p>To evaluate the 5-year impact of L4-S1 SL restoration on revision rates and to introduce the concept of “Symptomatic Conversion Rate” to quantify the clinical progression of ASD.</p> Study Design <p>A multicenter, retrospective cohort study.</p> Patient Sample <p>A total of 232 patients who underwent L4-S1 transforaminal lumbar interbody fusion (TLIF) with a minimum 5-year follow-up were included. The cohort was stratified into Adequate and Inadequate Restoration groups based on postoperative L4-S1 SL.</p> Outcome Measures <p>The primary endpoint was the 5-year revision surgery rate. Secondary endpoints included radiographic parameters (pelvic tilt [PT], pelvic incidence-lumbar lordosis [PI-LL] mismatch), implant failure rates, and patient-reported outcome measures (Oswestry Disability Index [ODI], Visual Analog Scale [VAS]). The “Symptomatic Conversion Rate” (the percentage of patients with radiographic ASD progressing to symptomatic ASD) was also assessed.</p> Methods <p>Clinical and radiographic data collected at a minimum of 5 years postoperatively were retrospectively analyzed. The cohorts were compared to assess the influence of L4-S1 SL restoration on long-term survivorship, functional recovery, and ASD progression.</p> Results <p>Baseline demographics and PI were comparable between groups (<i>P</i> &gt; 0.05). At the 5-year follow-up, the Inadequate Group exhibited significant pelvic retroversion (PT increased to 21.82° vs. 17.26° in the Adequate Group, <i>P</i> &lt; 0.001). Although radiographic ASD was prevalent in both cohorts (58.1% vs. 38.1%), the Symptomatic Conversion Rate was markedly higher in the Inadequate Group (73.3% vs. 28.1%, <i>P</i> &lt; 0.001). Consequently, the 5-year revision rate was significantly greater in the Inadequate Group (26.4% vs. 2.4%, <i>P</i> &lt; 0.001). The Inadequate Group also demonstrated inferior ODI scores (28.5 vs. 14.2, <i>P</i> &lt; 0.001) and an increased incidence of screw loosening.</p> Conclusions <p>Inadequate L4-S1 SL restoration is an independent risk factor for long-term revision surgery and implant failure following TLIF. Precise restoration provides a crucial “biomechanical buffer,” preventing compensatory pelvic retroversion and significantly reducing the conversion of radiographic ASD into symptomatic disease. Achieving this protective buffer should be a primary surgical objective to maximize long-term construct survivorship.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

“The protective buffer”: Adequate L4-S1 lordosis restoration reduces the symptomatic conversion of radiographic ASD and long-term revision rates — A 5-year multicenter cohort study

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年7月30日

查看全文
  • Chen Wang,
  • Zhifeng Dong,
  • Jing Jia,
  • GuangYi Zhang,
  • Xirong Fan,
  • Kai Zhang,
  • Wen Xue,
  • Qilong Wang,
  • Zeng Ping Wang,
  • ShuanHu Lei

摘要

Background

Inadequate restoration of L4-S1 segmental lordosis (SL) is a recognized contributor to adjacent segment disease (ASD). However, evidence regarding its impact on long-term revision rates remains conflicting, primarily due to short follow-up periods that fail to capture the critical transition from radiographic degeneration to symptomatic disease.

Purpose

To evaluate the 5-year impact of L4-S1 SL restoration on revision rates and to introduce the concept of “Symptomatic Conversion Rate” to quantify the clinical progression of ASD.

Study Design

A multicenter, retrospective cohort study.

Patient Sample

A total of 232 patients who underwent L4-S1 transforaminal lumbar interbody fusion (TLIF) with a minimum 5-year follow-up were included. The cohort was stratified into Adequate and Inadequate Restoration groups based on postoperative L4-S1 SL.

Outcome Measures

The primary endpoint was the 5-year revision surgery rate. Secondary endpoints included radiographic parameters (pelvic tilt [PT], pelvic incidence-lumbar lordosis [PI-LL] mismatch), implant failure rates, and patient-reported outcome measures (Oswestry Disability Index [ODI], Visual Analog Scale [VAS]). The “Symptomatic Conversion Rate” (the percentage of patients with radiographic ASD progressing to symptomatic ASD) was also assessed.

Methods

Clinical and radiographic data collected at a minimum of 5 years postoperatively were retrospectively analyzed. The cohorts were compared to assess the influence of L4-S1 SL restoration on long-term survivorship, functional recovery, and ASD progression.

Results

Baseline demographics and PI were comparable between groups (P > 0.05). At the 5-year follow-up, the Inadequate Group exhibited significant pelvic retroversion (PT increased to 21.82° vs. 17.26° in the Adequate Group, P < 0.001). Although radiographic ASD was prevalent in both cohorts (58.1% vs. 38.1%), the Symptomatic Conversion Rate was markedly higher in the Inadequate Group (73.3% vs. 28.1%, P < 0.001). Consequently, the 5-year revision rate was significantly greater in the Inadequate Group (26.4% vs. 2.4%, P < 0.001). The Inadequate Group also demonstrated inferior ODI scores (28.5 vs. 14.2, P < 0.001) and an increased incidence of screw loosening.

Conclusions

Inadequate L4-S1 SL restoration is an independent risk factor for long-term revision surgery and implant failure following TLIF. Precise restoration provides a crucial “biomechanical buffer,” preventing compensatory pelvic retroversion and significantly reducing the conversion of radiographic ASD into symptomatic disease. Achieving this protective buffer should be a primary surgical objective to maximize long-term construct survivorship.