Fusion and repeat discectomy following single level open lumbar discectomies. Survival analysis Dr John Mortimer Mr Chris Hoffman CCDHB and TBI Health group
Sciatica = Leg Dominant Pain Patients referred for surgical review History of back and then leg-dominant pain Severe disability unable to work and sleep Associated neurological disturbance Conservative care Nortriptyline for sleep disturbance CT guided steroid injection NSAIDS/Opiates prn Physiotherapy
Failure of Resolution Indications for discectomy Leg dominant (CBI pattern 3) pain Positive tension signs SLR to reproduce Leg Dominant Pain Concordant MRI scan Disc prolapse at relevant level/side When should we operate? Must do - Cauda Equina Syndrome (rare) Should do - Progressive neurology (rare) Could do - Aim to reduce long term pain/disability Window of opportunity to intervene 3 to 12 months
Surgical Goals Resolution of leg pain Reduction in back pain Preventing further disability Goal of surgery Discectomy removes the displaced fragment Removes the irritation/pressure on the relevant nerve Surgical technique Cannot repair any nerve damage Cannot repair the annular defect Problem of recurrent prolapse and/or chronic back pain Conservative care initially Repeat discectomy (fragment only) Complete discectomy and spinal fusion
Aims and Methods To describe the rates of reoperation following single level lumbar discectomies by one surgeon between 2000-2016 To describe the complication rates To describe the prevalence and association of patient factors and MRI reported disk disease on the incidence of repeat same level discectomy and lumbar fusions
Aims and Methods Inclusion Single level primary discectomy for MRI proven disk prolapse L1-S1 No previous discectomy or fusion of any level Exclusion > one level discectomy Any previous spinal surgery Decompression for reasons other than HNP Any other combination of surgery fusion
Aims and Methods Single surgeon database 1998-2016 (Mana Orthopaedics) Private practice medical records MRI reports ACC coding ACC surgical request report - ARTP s Operation notes Hutt, Wairarapa & Wellington Hospital medical records Pacific Radiology Records (PACS)
Aims and Methods Patient risk factors Age Gender Level Disk morphology type Single level DDD versus multi level DDD Duration of symptoms Outcomes Indication for surgery recurrent leg, leg/back or back pain Patient undergoing same-level discectomy Patient undergoing discectomy and lumbar fusion Patient undergoing lumbar fusion Time to repeat surgery All complication/deaths/ re-admission <30days
Cohort demographics 522 patients M:F 6:4 Age Mean 44 Std. 14.1 0 10 20 30 40 50 60 70 80 90 Symptom Med. 37 wk duration IQR 20-69 <2 weeks 2 to 6 weeks 6 weeks to 3 months 3 to 6 6 months 1-2 years 2 to 5 5 to 10 >10 to 1 year
Cohort demographics Disk morphology central para-central foraminal Far Lateral Level L5-S1 L4-5 L3-4 L2-3 7% 3% 5% 2% 37% 48% 53% 45%
Survival without re-operation 34 per 1000 person-years 1 or more 20% no re-op 80%
Surgery for Pain 18% 45% Repeat Diskectomy + fusion Repeat Discectomy 37% Fusion
Recurrent Leg Dominant pain MRI with isolated recurrence 8.0 % 12 per 1000-person-years Mean age 44.6yr M:F 48 : 52 Med. Symptom duration 46.5 wk Single : multi-level disease 60 : 40 Mean time to re-operation 1.0 yr
Revision rate (per 1000 person-years) Rate of repeat discectomy leg pain 700 600 500 400 300 R² = 0.90 200 100 0 0 1 2 3 4 5 6 7 8 Post-Op time (Years)
% survival Isolated Repeat Discectomy survival 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 2 4 6 8 10 12 14 16 18 Post-op (yr)
Recurrent Leg and Back pain MRI shows prolapse and further degeneration 5.0 % 3.3 per 1000-person-years Mean age 44 M:F 65 : 35 Med. Symptom duration 39 wk Single : multi-level disease 87 : 13 Mean time to re-operation 1.5 yr
Rate (1000-person-years) Rate of Discectomy + Fusion 250 200 150 100 R² = 0.94 50 0 0 2 4 6 8 10 12 14 Time (yr)
Survival (%) Survival Fusion + Discectomy 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 2 4 6 8 10 12 14 16 18 Time (yr)
Fusion for back pain Back dominant pain Failed conservative care MRI with local progression of disc degeneration 3.6% 2.3 per 1000-person-years Mean age 43.6yr M:F 42 : 58 Med. Symptom duration 37 wk Single : multi-level disease 82 : 18 Mean time to re-operation 3.9 yr
Rate (1000-person-years) Rate of isolated fusion for back pain 10 9 8 7 6 5 4 3 2 1 0 0 2 4 6 8 10 12 14 Time (yr)
% survival Survival Isolated fusion for back pain 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 2 4 6 8 10 12 14 16 18 post-op (yr)
Demographic risk factors Isolated discectomy Fusion + discectomy Isolated fusion Age 1.02 p=0.64 1.01 p=0.90 0.998 p=0.98 Duration 0.617 p=0.57 0.802 p=0.57 0.966 p=0.97 Gender M:F 0.624 p=0.14 1.10 p=0.68 0.474 p=0.15
Single Level Disk disease vs Multi-Level Disk Disease Isolated discectomy Fusion + discectomy Isolated fusion Single v Multiple Disk 0.670 p=0.21 1.25 p=0.10 2.09 p=0.29
Flaws and future Subjective markers of patient outcomes influenced by surgically candidacy and surgical decision making Doesn t objectively measure pre or post op leg/back pain and quality of life measures (SF-36, ODI) Loss to F/U Next Step: Spine Surgery Registry Prospective collection of Patient outcomes VAS, EQ5D and ODI Revision procedures recorded on registry