Gender differences in pain and function during recovery from spinal arthrodesis surgery

2017

Background

Stereotypes exist in modern society regarding perceived gender differences involving the perception of pain. Some studies suggest that women have a lower tolerance to painful mechanical, electrical, and thermal stimuli than men. Certain spinal pathologies are more prevalent among females, but the understanding of gender differences in the response to pain has not been well studied after spinal arthrodesis.

Purpose

Analyze gender differences regarding the recovery experience after spinal fusion

Study Design

Prospective outcomes study from consecutive multi-surgeon series at one center

Patient Sample

All adult patients (1931) who underwent open primary or revision instrumented posterior arthrodesis, with 24mo follow-up (range 24-189mo)

Outcome measures

Male (M) vs Female (F) differences in Visual Analog Pain (VAS), Oswestry Disability Index (ODI), pain medication, and complications. Statistical analysis: T-Test, Chi square, linear regression, Mann Whitney U Test, Spearman’s rho.

Methods

Patients were divided by gender. Outcome differences were analyzed by: major diagnosis (Degen vs Deformity), specific diagnosis (scoliosis, etc.), single vs multilevel fusion, primary (1045) vs revision fusion (886), age (18-53yrs, 54-63yrs, 64-71yrs, 71-91yrs), comorbidities, BMI, revision vs no revision during follow-up, and complications. VAS, ODI, pain medication were collected pre-op, 6wks, 3mo, 6mo, 1yr. Complications were analyzed over average 7 years followup.

Results

1931 patients enrolled (F-1219; M-712), age 60 yrs (range 18–90yrs; M-59yrs, F-61 yrs); Prior laminectomy-295, prior fusion-591; 300 smokers (16%). Diagnoses: spondylolisthesis-716, stenosis requiring fusion-611, idiopathic scoliosis-155, degenerative scoliosis-210, kyphosis-118, kyphoscoliosis-89, Scheuermann’s kyphosis-23, neuromuscular scoliosis-9. Degenerative group fusion avg 2.1 levels, Deformity group fusion avg 8.5 levels. Predictors of preop pain: F, comorbidities, longer fusions, degenerative diagnosis, and BMI. F had more deformity (p=0.000001), autoimmune, bladder, GI, depression, fibromyalgia, thyroid disorders (p<.002). Each co-morbidity predicted 1.69% increase in preop ODI. M had higher pre-op BMI (29.7 vs 28.7;p<0.01), more degen (p=0.000001). VAS/ODI scores for F were worse than M pre-op (6.5/49.7 vs 6.1/46.5; p=0.00005), 6 wks (4.3 vs 4.0; p=0.013), but was similar to M at 3mo (p=0.57), 6mo (p=0.61), 1yr (p=0.84). At 1 year, F had greater improvement (VAS p=0.002; ODI p=0.0007). Pain medication use was similar F vs M at all time points (p=0.66). Stratified by diagnosis, F had lower function and higher pain pre-op for degen: VAS/ODI 6.7/52 vs 6.2/47(p=0.00004); For deformity, F had more pain but similar function (6.3/46 vs 5.9/44; p=0.037, p=0.11). F had higher pain and lower function in both single (p=0.0003) and multilevel fusion (p=0.01). F had higher preop pain than M for all age groups (p=0.01–0.04), but older F (71-91yrs) had greater ODI improvement at 6wks and 1yr vs M (p=0.002). Among specific diagnoses, degen spondy had the largest gender specific outcome differences (p<0.0001). Of patients who required revision surgery, F improved VAS more than M (p=0.04); F had more adjacent fractures (p=0.07) and hardware loosening (p=0.003).

Conclusions

Analysis of gender specific outcomes revealed women had more pre-op pain but improved more at 6 weeks and 1 year than men, regardless of diagnosis, age, or levels fused. F had more pre-op co-morbidities and M had higher BMI, both correlating with outcomes. F also had more complications. Gender differences exist in the recovery experience after spinal arthrodesis.