Complications, Outcomes and Need for Fusion Following Minimally Invasive Posterior Cervical Foraminotomy and Microdiscectomy

Presented at SMISS Annual Forum 2013
By Branko Skovrlj MD
With Richard Fessler MD, PhD, Yakov Gologorsky MD, Raqeeb Haque MD, Sheeraz Qureshi MD, MBA,

Disclosures: Branko Skovrlj MD None Richard Fessler MD, PhD None, Yakov Gologorsky MD None, Raqeeb Haque MD None, Sheeraz Qureshi MD, MBA A; Cervical Spine Research Society. B; Zimmer-Biomet, Stryker Spiner, Globus Medical, Inc. D; Avaz Surgical. F; RTI, Zimmer-Biomet, Stryker Spine,

Introduction: Posterior cervical foraminotomy (PCF) with or without microdiscectomy (PCD) is a frequently used surgical technique for cervical radiculopathy secondary to foraminal stenosis or a laterally located, herniated disc. Currently, these procedures are being performed with increasing frequency using advanced minimally invasive techniques. While the safety and efficacy of minimally invasive PCF/PCD (MI-PCF/PCD) has been established, reports on long-term outcome and need for secondary surgical intervention at the index or adjacent level are lacking.

Methods: We prospectively followed 70 patients who underwent MI-PCF with or without MI-PCD (95 cervical levels) between 2002 and 2011. The primary outcomes assessed were need for secondary surgical intervention at the index or adjacent level. The secondary outcomes assessed included complications and improvements in Neck Disability Index (NDI) and Visual Analog Scale Neck/Arm (VASN/A) scores. All complications were reviewed. Mixed model ANOVAs (analysis of variance) with random subject effects and autoregressive order 1 correlation structures were used to test for differences among NDI, VASA and VASN measurements made over time while accounting for the correlation among repeated observations within a patient. All statistical hypothesis testing was conducted at the 5% level of significance.

Results: Patients were followed for a mean of 32.1 months. Of 70 patients operated, there were 3 (4.3%) complications (1 cerebrospinal fluid leak, 1 postoperative wound hematoma, and 1 radiculitis), none of which required a secondary operative intervention. Five patients required an anterior cervical discectomy and fusion (8 total levels fused) on average 44.4 months following the index surgery. Of those, 5 (5.3%) were at the index level and 3 (2.1%) were at adjacent levels. NDI scores improved significantly (p<0.0001) immediately postoperatively, and continued to decrease gradually with time. VASN/A scores improved significantly (p<0.0001) from baseline immediately postoperatively, but tended to plateau with time.

Conclusion: MI-PCF with or without MI-PCD is an excellent alternative for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. There is a low rate (1.1% per index level per year) of future index site fusion, as well as a very low rate (0.9% per adjacent level per year) of adjacent level disease requiring surgery.