Functional Outcomes following Lumbar Decompression: Analysis of a Workman’s Compensation Population

Presented at SMISS Annual Forum 2014
By Kern Singh MD
With Sreeharsha Nandyala BA, Alejandro Marquez-Lara MD, Islam Elboghdady , Eric Sundberg MD, Hamid Hassanzadeh MD, Anton Jorgensen MD, Khaled Aboushaala MD, Blaine Manning BS, Mohamed Noureldin MD,

Disclosures: Kern Singh MD A; CSRS Resident Grant. B; DePuy, Zimmer, Stryker, CSRS, ISASS, AAOS, SRS, Vertebral Column - ISASS. D; Avaz Surgical, LLC, Vital 5, LLC. F; Zimmer, Stryker, Pioneer, Lippincott Williams & Wilkins, Th Sreeharsha Nandyala BA None, Alejandro Marquez-Lara MD None, Islam Elboghdady None, Eric Sundberg MD None, Hamid Hassanzadeh MD None, Anton Jorgensen MD None, Khaled Aboushaala MD None, Blaine Manning BS None, Mohamed Noureldin MD None,

Introduction:
WC patients with stenosis and radiculopathy may require lumbar decompressive surgery in order to alleviate pain and facilitate return to work. However, the ability to meet “pre-injury” job requirements following lumbar spine surgery has not been previously described.

Aims/Objectives:
To assess the clinical and functional outcomes of Workman’s compensation (WC) patients following a one or two level minimally invasive (MIS) lumbar decompression (LD).

Methods:
115 WC patients who underwent a primary one- or two-level MIS LD procedure (laminectomy with or without discectomy) for degenerative spinal pathology between 2007-2013 were analyzed. Patient demographics, comorbidity burden (CCI), smoking status, intraoperative parameters, length of hospitalization, visual analogue scale (VAS) scores, and re-herniation rates were assessed. A subgroup analysis of patients with available functional capacity evaluation (FCE) records was performed to compare outcomes between patients who met and did not meet job requirements. Statistical analysis was performed with chi-squared test for categorical variables and Student-Test for continuous variables. A p-value of <0.05 denoted statistical significance.

Results:
The mean age, CCI, and preoperative VAS scores were 42.1 years (±10.8), 1.32 (±1.54), and 6.8 (±1.9) respectively. The re-herniation rate was 5.2% (n=6) and 23.5% (n=27) of patients required a reoperation. Of the 72 patients with available FCEs, 27.8% (n=20) met pre-injury job requirements. Patients who did not meet job requirements were older (43.6±10.3 vs 37.6±10.6, p<0.05) and demonstrated a greater comorbidity burden (CCI: 1.59±1.62 vs 0.67±1.17, p<0.05). There were no significant differences in intraoperative parameters, peri-operative VAS scores, or re-herniation rates between cohorts. Patients who did not meet job requirements more often underwent a re-operation (34.6% vs 15.0%, p<0.05). Patients with heavy (63.5% vs 25.0%; p<0.05) or very heavy (9.6% vs 5.0%; p<0.05) job requirements were less likely to meet job requirements. In contrast, patients with light (15.0% vs 0.0%, p<0.05) and medium requirements (55.0% vs 26.9%, p<0.05) were more likely to meet job requirements. The majority of patients (63.5%) who did not meet job requirements demonstrated a minimum functional ability of medium work level.

Conclusions:
This analysis demonstrated that WC patients undergoing an MIS LD were likely to obtain at least a medium demand work level (63.5%) based upon objective functional capacity evaluations. Patients with heavy and very heavy physical job requirements are less likely to regain total functional capacity after undergoing a minimally invasive lumbar decompression surgery. These findings may be valuable for counseling patients regarding their return-to-work expectations following lumbar decompressive surgery.