Influence of Obesity on Outcomes of Surgery for Lumbar Spinal Canal Stenosis

Impact of body mass index on outcomes after lumbar spine surgery

The impact of body mass index (BMI) on outcomes after lumbar spine surgery is currently unknown. Previous studies have reported conflicting evidence for patients with high BMI, while little research has been conducted on outcomes for underweight patients. This study aims to examine the impact of BMI on outcomes after lumbar spine surgery. This prospective cohort study enrolled 5622 patients; of which, 194, 5027, and 401 were in the low (< 18.5 kg/m²), normal (18.5-30), and high (≥ 30) BMI groups, respectively. Pain was assessed via the numerical pain rating scale (NPRS) for the lower back, buttock, leg, and plantar area. Quality of life was assessed via the EuroQol 5 Dimension (EQ-5D) and Oswestry Disability Index (ODI). Inverse probability weighting with propensity scores was used to adjust patient demographics and clinical characteristics between the groups. After adjustment, the 1-year postoperative scores differed significantly between groups in terms of leg pain. The proportion of patients who achieved a 50% decrease in postoperative NPRS score for leg pain was also significantly different. Obese patients reported less improvement in leg pain after lumbar spine surgery. The outcomes of patients with low BMI were not inferior to those of patients with normal BMI.

Complications and outcomes of open posterior lumbar spinal fusion surgery in obese patients: a meta-analysis

OBJECTIVE

The aim of this study was to determine whether obesity affects the operation, complications and outcomes after open posterior lumbar spinal fusion surgery for the treatment of low back pain and leg pain.

METHODS

A meta-analysis of studies that compared the outcome of posterior lumbar spinal fusion in obese and non-obese patients. A total of 16 studies were included.

RESULTS

There was no difference in pain and functional outcomes. Posterior lumbar spinal fusion in obese patients resulted in a statistically significant increase in intra-operative blood loss (weighted mean difference 40.93, 95% confidence interval (CI) 15.97-65.90, n = 243, and p=.001), longer duration of surgery (weighted mean difference -1.64, 95% CI -4.12 to 0.84, n = 1460, and p=.19), more complications (odds ratio: 1.59, 95% CI 1.24-2.05, n = 339, and p<.001) and extend length of stay (weighted mean difference 0.31, 95% CI 0.07-0.55, n = 1408, and p=.01).

CONCLUSIONS

Obese patients experience more blood loss, longer duration of surgery, more complications and extended length of stay, but their back and leg pain and functional outcomes are similar to non-obese patients. Based on these results, obesity is not a contraindication to open posterior lumbar spinal fusion surgery.

Surgical and Clinical Results of Minimally Invasive Spinal Fusion Surgery in an Unselected Patient Cohort of a Spinal Care Unit

OBJECTIVES

To review the surgical results and to identify possible parameters influencing the clinical outcomes in an unselected patient collective undergoing minimally invasive lumbar interbody fusion in a spinal care unit.

METHODS

A total of 229 adult patients who underwent minimally invasive lumbar spinal fusion between 2008 and 2016 were included in this retrospective analysis. Lumbar fusion was performed using transforaminal interbody fusion (TLIF) devices and posterolateral fusion. To eliminate confounding parameters, in all patients interbody fusion was indicated by lumbar degenerative pathologies, and surgery was performed using the same fusion device. Treatment efficacy was evaluated using scores describing pain (visual analogue scale [VAS]) and health impairment (EQ-5D, Oswestry Disability Index [ODI]). The influence of patient age, obesity, active smoking status, and co-morbidities on clinical outcome and perioperative complications was analyzed.

RESULTS

The patient population reviewed had improved VAS (P_{(leg pain)} ≤ 0.0001, P_{(back pain)} ≤ 0.0001), ODI (P ≤ 0.0001), EQ-VAS (P ≤ 0.0001), and EQ-5D subscales "mobility", "self-care", "pain", and "anxiety" (P_(mobility) ≤ 0.0001, P_(self-care)  = 0.41, P_(pain) ≤ 0.0001, P_(anxiety)  = 0.011) postoperatively. Neither advanced patient age, nor increased body mass index (BMI), hypertension, or active smoking status had a significantly limiting influence on the success of minimally invasive spinal surgeries (MIS). Duration of surgery strongly correlated with the number of spinal levels treated and with intraoperative blood loss (r = 0.774, P ≤ 0.0001, n = 208). Weak positive correlations were found between patient age and duration of surgery (r = 0.184, P = 0.005, n = 229), intraoperative blood loss (r = 0.165, P = 0.012, n = 229), and duration of hospitalization (r = 0.270, P ≤ 0.0001, n = 228), respectively. When compared to non-smokers, smokers were younger (P ≤ 0.0001), and had a significantly lower BMI (P = 0.001), shorter durations of surgery (P ≤ 0.0001), decreased intraoperative blood loss (P = 0.022), and shorter hospital stays (P = 0.006), respectively. Complications occurred in 17 patients (7%) and were not affected by patient age, BMI, hypertension, or active smoking status.

CONCLUSION

Minimally invasive spinal surgery is a safe and effective treatment option and may be superior to open surgery in subpopulations with significant co-morbidities and risk factors, such as elderly and obese patients as well as patients with an active smoking status.

Outcome of lumbar spinal fusion surgery in obese patients

The aim of this study was to determine whether obesity affects pain, surgical and functional outcomes following lumbar spinal fusion for low back pain (LBP).

A systematic literature review and meta-analysis was made of those studies that compared the outcome of lumbar spinal fusion for LBP in obese and non-obese patients. A total of 17 studies were included in the meta-analysis. There was no difference in the pain and functional outcomes. Lumbar spinal fusion in the obese patient resulted in a statistically significantly greater intra-operative blood loss (weighted mean difference: 54.04 ml; 95% confidence interval (CI) 15.08 to 93.00; n = 112; p = 0.007) more complications (odds ratio: 1.91; 95% CI 1.68 to 2.18; n = 43858; p < 0.001) and longer duration of surgery (25.75 mins; 95% CI 15.61 to 35.90; n = 258; p < 0.001). Obese patients have greater intra-operative blood loss, more complications and longer duration of surgery but pain and functional outcome are similar to non-obese patients. Based on these results, obesity is not a contraindication to lumbar spinal fusion.

Cite this article: Bone Joint J 2015;97-B:1395–1404.

Functional outcome of primary hamstring anterior cruciate ligament reconstruction in patients with different body mass index classes

PURPOSE

We compared functional outcomes after primary hamstring-graft anterior cruciate ligament (ACL) reconstruction in patients with different body mass index (BMI) classes.

METHODS

Functional outcomes after ACL reconstruction were measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Lysholm score. The procedures were carried out by a single surgeon between 2001 and 2009 in 2 groups of patients with different BMI classes: a normal-BMI group (BMI 18.5 to 24.9) and a high-BMI group (BMI ≥ 25), with a minimum of 2 years' follow-up. Rolimeter readings for ligament laxity as well as complications between the 2 groups were also analyzed.

RESULTS

A total of 92 patients were reviewed, with the normal-BMI group consisting of 49 patients, whereas there were 43 patients in the high-BMI group. There were no significant differences between the groups in any of the preoperative and postoperative scores or ligament laxity. Both groups showed comparable clinically significant improvement in their postoperative scores compared with their preoperative scores. Patients in the high-BMI group had a slightly increased postoperative complication rate when compared with the normal-BMI group.

CONCLUSIONS

Primary hamstring ACL reconstruction is an effective treatment option in patients irrespective of preoperative BMI. High BMI does not adversely affect functional outcomes as measured by the KOOS and Lysholm scores up to and at 2 years postoperatively, and these patients benefit in a manner comparable to that of patients with normal BMI.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.