Arunakul Rattalerk, Metzger Melodie, Kanim Linda, Bae Hyun, Kropf Michael, Delamarter Rick
Department of Orthopaedics, Faculty of Medicine, Thammasat University, Pathumthani, Thailand.
Spine Center, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
Asian Spine J. 2017 Apr;11(2):249-255. doi: 10.4184/asj.2017.11.2.249. Epub 2017 Apr 12.
Retrospective review of a patient cohort through a prospective study.
To determine whether there are correlations between radiographic measurements, including sacral slope (SS) and pelvic incidence (PI), and self-reported clinical outcomes among single-level L5/S1 ProDisc-L patients.
The lumbosacral juncture presents unique biomechanical challenges with respect to artificial disc replacement (ADR) because of its orientation and consequential shear loading. Reports of inferior outcomes at L5/S1 compared to those of the outcomes at the levels above, including increased facet joint pain, suggest a relationship with the sacral inclination at L5/S1.
Plain standing lateral radiographs of 71 patients (age, 26-65 years) who underwent ADR at L5/S1 for degenerative disc disease were reviewed. SS and PI were measured based on pretreatment and initial follow-up standing films. Patient's average adjusted self assessments included the Oswestry disability index and visual analog scale for pain 2 years after ADR. Correlation coefficients were computed to evaluate relationships between radiographic parameters and clinical outcomes. Analysis of covariance was used to evaluate multivariate relationships among factors, including radiographic parameters, body mass index (BMI), and clinical outcomes.
SS and PI values were obtained from 71 patients. The average SS was 33.3° and average PI was 39.9°. At the 24-month follow-up, no significant correlations (≥0.05) were observed between radiographic parameters and clinical outcomes. BMI, age, and sex did not explain any variability in the relationships between clinical outcomes and SS and PI.
We reviewed a large range of SS angles and found no associations between SS, PI, or BMI and clinical outcomes after ADR at L5/S1. These preliminary results demonstrate that ADR provided maintainence of pain relief and functional improvement for a wide range of SS angles, suggesting that steeper angles are not a contraindication for ADR.
通过前瞻性研究对患者队列进行回顾性分析。
确定在单节段L5/S1 ProDisc-L患者中，包括骶骨倾斜角（SS）和骨盆入射角（PI）在内的影像学测量值与自我报告的临床结果之间是否存在相关性。
由于腰骶关节的方向和随之而来的剪切负荷，其在人工椎间盘置换（ADR）方面呈现出独特的生物力学挑战。与上方节段相比，L5/S1节段预后较差的报道，包括小关节疼痛增加，提示与L5/S1节段的骶骨倾斜度有关。
回顾性分析71例（年龄26 - 65岁）因退行性椎间盘疾病在L5/S1节段接受ADR手术患者的站立位腰椎侧位X线片。基于术前和初次随访的站立位片测量SS和PI。患者的平均调整后自我评估包括ADR术后2年的Oswestry功能障碍指数和疼痛视觉模拟评分。计算相关系数以评估影像学参数与临床结果之间的关系。采用协方差分析评估包括影像学参数、体重指数（BMI）和临床结果等因素之间的多变量关系。
获取了71例患者的SS和PI值。平均SS为33.3°，平均PI为39.9°。在24个月的随访中，未观察到影像学参数与临床结果之间存在显著相关性（≥0.05）。BMI、年龄和性别并不能解释临床结果与SS和PI之间关系的任何变异性。
我们分析了大范围的SS角度，发现L5/S1节段ADR术后SS、PI或BMI与临床结果之间无相关性。这些初步结果表明，ADR在大范围的SS角度下都能维持疼痛缓解和功能改善，提示更大的角度并非ADR的禁忌证。
