PLF+PS or ALIF+PS: which has a lower operative nonunion rate? Analysis of a cohort of 2,061 patients from a National Spine Registry.

BACKGROUND CONTEXT: Although fusion rates in posterolateral lumbar fusions with pedicle screws (PLF+PS) and anterior lumbar interbody fusions with pedicle screws (ALIF+PS) have been reported, there has been no consensus on superiority with respect to clinical outcome and nonunion rates. Most studies determine nonunion rates based on radiographic studies; however, many of these nonunions are asymptomatic and may not require reoperations. Hence, a potentially more clinically useful measure is the reoperation rate for symptomatic nonunions, which we term the operative nonunion rate. PURPOSE: To determine if there is a difference in operative nonunion rates between PLF+PS versus ALIF+PS. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Adult patients (≥18 years old) with the diagnosis of lumbar spondylolisthesis or lumbar spinal stenosis who underwent primary elective PLF+PS and ALIF+PS for 1-level and 2-level fusions (L4-S1) between 2009 and 2018. OUTCOME MEASURES: Reoperation rates for symptomatic nonunions (ie, operative nonunion rates). METHODS: Patients were followed until validated operative nonunions, membership termination, death, or 03/31/2019. Descriptive statistics and 2-year incidence rates for operative nonunions were calculated by fusion-level, fusion type, and levels fused. Time-dependent multivariable Cox-Proportional Hazards regression was used to evaluate operative nonunion rates with adjustment for covariates or risk change estimates more than 10%. RESULTS: We identified 2,061 patients (PLF+PS:1,491, ALIF+PS:570) with average follow-up time of 4.8 (±3.1) years and average time to operative nonunion of 1.3 (±1.2) yrs. Comparatively, unadjusted 1-level and 2-level incidence rates for operative nonunions were higher in PLF+PS versus ALIF+PS. For 1-level procedures these were 0.9% (95% CI=0.4-1.6) versus 0.6% (95% CI=0.1-2.1); 2-level, 2.0% (95% CI=0.8-4.0) versus 0.9% (95% CI=0.1-3.3). However, there were no observed significant differences in risks for operative nonunions in multivariable models comparing PLF+PS versus ALIF+PS (HR=0.3, 95% CI=0.1-1.1), 1-level versus 2-level fusions (HR=1.8, 95% CI=0.8-4.3), or by fusion level (L4-L5: HR=1.0, 95% CI=0.4-2.7; L5-S1: HR=2.0, 95% CI=0.7-5.4). CONCLUSIONS: A large cohort of patients with lumbar fusions between L4 to S1 and an average follow-up of >4 years found that although there was a trend for higher operative nonunions in PLF+PS compared with ALIF+PS, this was not statistically significant. The role of spinal alignment was not investigated.

Operative Nonunion Rates in Posterolateral Lumbar Fusions: Analysis of a Cohort of 2591 Patients from a National Spine Registry.

OBJECTIVE: Radiographic nonunion rates in the literature for posterolateral lumbar fusions with pedicle screws (PLFs) range from 8.1% to 43.3% but may not represent nonunion rates. A few small studies have reported reoperations for symptomatic nonunions (operative nonunions) to range from 3.2% to 13.9%. The objective of this study is to determine operative nonunion rates for 1-level, 2-level, 3-level, and ≥4-level PLFs and to determine the risks for these nonunions. METHODS: A retrospective cohort study, using data from the Kaiser Permanente Spine Registry, identified adult patients (≥18 years old) who underwent PLFs for degenerative disc disease. Multivariable Cox proportional hazards regression and Kaplan-Meier survival estimates using the log-rank statistic were used to evaluate operative nonunion rates. RESULTS: The cohort consisted of 2591 patients with single-level and multilevel PLFs with mean follow-up of 4.6 years, time to operative nonunion of 1.52 years, and 2-year operative nonunion rate of 1.08%. Compared with single-level fusions, patients with 3-level and ≥4-level fusion had 2.8 and 3.7 times higher risk of operative nonunions. Patients with PLFs involving L5-S1 had 2.5 times the risk of an operative nonunion compared with those without. CONCLUSIONS: Our study reports results from one of the largest cohort of patients for the first time with single-level and multilevel instrumented PLFs and found a 2-year operative nonunion rate of 1.08% with increased risk of nonunion for constructs that included L5-S1 and ≥3-level fusions. Operative nonunion combines clinical and radiographic data and provides an alternative measure of fusion rates.

Common rotational variations in children.

Most rotational variations in young children, such as in-toeing, out-toeing, and torticollis, are benign and resolve spontaneously. Understanding the normal variations in otherwise healthy children is vital to identifying true structural abnormalities that require intervention. A deliberate assessment of the rotational profile is necessary when evaluating children who in-toe or out-toe. In-toeing is usually attributable to metatarsus adductus in the infant, internal tibial torsion in the toddler, and femoral anteversion in children younger than 10 years. Out-toeing patterns largely result from external rotation hip contracture, external tibial torsion, and external femoral torsion. Although congenital muscular torticollis is the most common explanation for the atypical head posture in children, more serious disorders, including osseous malformations, inflammation, and neurogenic disorders, should be excluded.

Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and anular competence.

BACKGROUND: The surgical treatment of sciatica with discectomy is ineffective in a sizable percentage of patients, and reherniation occurs after 5% to 15% of such procedures. The purpose of the present study was to determine if competence of the disc anulus and the type of herniation could be used to predict postoperative clinical outcomes following lumbar discectomy. METHODS: A prospective observational study of 187 consecutive patients undergoing single-level primary lumbar discectomy was conducted. A single surgeon performed all of the procedures, and an independent examiner evaluated 180 of the patients clinically at a minimum of two and a median of six years after surgery. The extent of anular deficiency and the presence of disc fragments were determined. On the basis of these intraoperative findings, disc herniations were classified into four categories: (1) Fragment-Fissure herniations (eighty-nine patients), (2) Fragment-Defect herniations (thirty-three patients), (3) Fragment-Contained herniations (forty-two patients), and (4) No Fragment-Contained herniations (sixteen patients). The effects of disc herniation morphology and preoperative variables on subsequent clinical outcome were determined with the Student t test for continuous variables and chi-square analysis for categorical variables. RESULTS: Patients in the Fragment-Fissure group, who had disc fragments and a small anular defect, had the best overall outcomes and the lowest rates of reherniation (1%) and reoperation (1%). Patients in the Fragment-Contained group had a 10% rate of reherniation and a 5% rate of reoperation. Patients in the Fragment-Defect group, who had extruded fragments and massive posterior anular loss, had a 27% rate of reherniation and a 21% rate of reoperation. Patients in the No Fragment-Contained group did poorly: 38% had recurrent or persistent sciatica, and the standard outcomes scores were less improved compared with those in the other groups (p < 0.001). CONCLUSION: Intraoperative findings, as described in the present study, were more clearly associated with outcomes than were demographic, socioeconomic, or clinical variables. The degree of anular competence after discectomy and the type of herniation appear to have value for the prediction of the recurrence of sciatica, reoperation, and clinical outcome following lumbar discectomy. LEVEL OF EVIDENCE: Prognostic study, Level I-1 (prospective study). See p. 2 for complete description of levels of evidence.