A Systematic Review of Propensity Score Matching in the Orthopedic Literature

Pelvic Incidence-Lumbar Lordosis Mismatch Is Not Associated with Early Reoperation for Adjacent Segment Disease After Lumbar Fusion

OBJECTIVE

To compare the 2-year reoperation rates for adjacent segment disease between patients with pelvic incidence-lumbar lordosis (PI-LL) mismatch postoperatively and patients with normal PI-LL measurements.

METHODS

Patients undergoing elective 1- to 2-level lumbar fusion for degenerative conditions between 2016 and 2018 were retrospectively reviewed. Spinopelvic radiographic parameters immediately postoperation were measured, and PI-LL mismatch was determined using the age-adjusted thresholds defined in Lafage et al. After propensity score matching, early reoperation rates were compared between the PI-LL mismatch and normal PI-LL cohorts. Early reoperation was defined as symptomatic adjacent segment disease (ASD) requiring reoperation within 2 years of the index surgery.

RESULTS

A total of 219 patients were identified. The average age was 59 years of age, with 59.8% female. The PI-LL mismatch cohort (n = 148) was younger (57.5 vs. 63.5 years, P < 0.001) and had a higher proportion of Black patients (31.8% vs. 11.3%, P = 0.001) than the normal PI-LL cohort, respectively. A total of 100 patients in the PI-LL mismatch cohort were propensity score matched to 66 patients in the normal PI-LL cohort, resulting in no difference in age (P = 0.177), sex (P = 0.302), race (P = 0.727), or body mass index (P = 0.892). Using these matched cohorts, the rate of early reoperation for ASD was 8.0% in the PI-LL mismatch cohort and 9.1% in the normal PI-LL cohort (P = 0.805), with a mean time to reoperation of 1.28 and 1.33 years, respectively.

CONCLUSIONS

After propensity score matching, PI-LL mismatch was not associated with early reoperation for ASD in patients undergoing 1- to 2-level lumbar fusions for degenerative conditions.

[Evidence-based versus expertise-based medicine in orthopedic and trauma surgery : There is nothing more practical than a good theory]

About a quarter of a century after the introduction of the concept and principles of evidence-based medicine (EbM), some healthcare providers are still adamant that these are incompatible with knowledge gained through experience. Across the surgical disciplines, it is often argued EbM underestimates or neglects the importance of intuition and surgical skills. To put it bluntly, these assumptions are wrong and often characterized by a misunderstanding of the methodology of EbM. Even the best controlled trial cannot be properly interpreted or implemented without clinical reasoning; furthermore, clinicians of all disciplines are obligated to provide care according to the current state of scientific knowledge. In an era of revolutionary biomedical developments, exponential increase of research but incremental innovations, they must become familiar with pragmatic tools to appraise the validity and relevance of clinical study results, and to decide whether there is a need to adapt current beliefs and practices based on the new information. We herein use the recent example of a new medical device for the surgical treatment of rotator cuff tears and subacromial impingement syndrome to illustrate how important it is to interpret data in the context of a precise, answerable question and to combine clinical expertise with methodological principles offered by EbM.

Influence of Preoperative Disability on Clinical Outcomes in Patients Undergoing Anterior Lumbar Interbody Fusion

BACKGROUND

Few studies have examined the influence of preoperative disability through the Oswestry Disability Index (ODI) on clinical outcomes in patients undergoing anterior lumbar interbody fusion (ALIF).

METHODS

Patients undergoing ALIF were separated into 2 groups based on ODI<41 (lower disability) versus ODI≥41% (higher disability). Patient-reported outcomes (PROs) were collected at preoperative and postoperative 6-week/12-week/6-month/1-year/2-year time points. Physical function PROs were Patient-Reported Outcomes Measurement Information System Physical Function and 12-item Short Form Physical Component Score. Mental function PROs were 12-item Short Form Mental Component Score and Patient Health Questionnaire-9. Pain PROs were visual analog scale back and visual analog scale leg. ODI was the disability PRO.

RESULTS

A total of 148 patients were identified, with 52 patients with lower disability. Higher disability patients demonstrated significant improvement in mental function (P ≤ 0.010, all). Lower disability patients demonstrated superior postoperative PROs in physical function, mental function, back pain, and disability outcomes (P ≤ 0.034, all). Minimum clinically important difference achievement rates for lower disability patients were higher for back pain and lower for mental function and disability outcomes (P ≤ 0.041, all).

CONCLUSIONS

Independent of preoperative disability, patients undergoing ALIF reported significant postoperative improvement in physical function, pain, and disability outcomes. Patients with lower preoperative disability continued to report superior PROs in mental function, back pain, and disability postoperatively. Minimum clinically important difference achievement rates for lower disability patients were higher for back pain and lower in mental function and disability outcomes. Patients undergoing ALIF with higher preoperative disability may experience greater clinically meaningful improvement in mental function and disability.