Fusion and Repeat
Discectomy following Single Level Open Lumbar Discectomies. Survival Analysis
Mortimer JR, Hoffman C
Background: single level discectomy for
lumbar disk herniation is the most common spinal surgery performed in the US.
Reoccurrence, and back pain secondary to spinal instability are among reasons
for dissatisfaction post-surgery. Many patients will require revision
discectomy and/or fusion procedures.
Aim: the Aim of this study is to
describe the rates, indications, complications and demographics of patients
undergoing lumbar fusions and repeat discectomies, following single level
lumbar discectomies by one surgeon between 2000-2016.
Methods: retrospective descriptive study
of 522 patients treated with primary single level open lumbar discectomy.
Demographics data, original MRI reports, evidence of repeat discectomy or
fusion gathered from a private database, ACC reports, regional Public hospital
databases and imaging databases.
Measures: demographic data; age, gender, duration
of symptoms, morphology of disk prolapse, and single level vs multilevel disk
disease. Outcome measures; all complications, all spinal operations, all fusions,
all repeat discectomies, isolated repeat discectomy and isolated fusion for
Results: 522 patients met criteria with
a mean follow up of 7.7 years. 20% of all patients required at least one
re-operation of any type. 5.9%, 10.5% and 10.4% at 1, 2 and 5 years
respectively. 54 (10.3%) patients required primary fusion. Indications for
fusion were any back pain (69%),back pain alone (38%),reoccurrence of HNP alone(32%), back pain + reoccurrence(28%), discitis(1.0%).
Mean time to fusion was 93 weeks post-op. mean rate was 14.3 per 1000person-years.
87% 10 year survival. 42 (8.0%) had a revision same level discectomy. Mean time
to revision was 102 weeks post-op. Mean rate 12 per 1000 person years. 83.0% 10
year survival. 3.1% of patients required adjacent level discectomy. There were
no statistically significant differences on rates of re-operation with the
measured risk factors. Total complication rate was 8.0%.
Conclusion: Reoccurrence and back pain
secondary to instability following single level discectomy is common problem
after discectomy for lumbar disk prolapse. 20% of patients who undertake will
eventually require a surgery on their spine. Pain, whether back or leg
dominant, is the most common indication for repeat operation. Repeat
discectomy, fusion or a combination being the most common repeat operation.