Stand Alone XLIF: patients selection

• Degenerative disc disease without significant sagittal or frontal deformity, Modic changes 1 or 2 of endplates

• No segmental instability at pre-op imaging, including LS flexion-extension X-Rays

• Good chance to improve radiculopaty with indirect decompression (no facet joint arthrodhesis)

• No wide posterior decompression needed (severe narrowing of spinal canal with claudicatio spinalis)

• No diagnosis of severe osteoporosis

Stand alone XLIF: why?

• Short operative time: better for elderly patients with co-morbidities• Minimal blood loss• Shorter hospitalization• Good cost/effectiveness

Stand alone XLIF: handicaps• Persistent radiculopaty : indirect decompression alone insufficient• Risk of subsidence of the cage (in particular 18 mm cages)• Amount of bone growth: biomechanical stability of cage alone

less than circumferential constructs• Risk of two stages surgery

Stand alone XLIF: FU criteria

• Pre-operative clinical assessment completed with ODI questionnaire, VAS B/VAS L ; pre-operative imaging with LS MRI + LS lateral and a-p flexion-extension Radiographs

• Clinical evaluation + LS lateral and a-p X-Ray at one month• ODI/VAS evaluation + LS lateral Flexion-extension X-Ray at three

months• ODI/VAS evaluation + LS lateral flexion-extension X-Rays at six

months• In poor grade outcomes, LS MRI was performed

Case collection

• October 2011-August 2013: 48 patients treated with XLIF approach: 17 male and 31 females, mean age 62 (range 39-81)

• Of the 48 patients, 37 were treated with stand alone XLIF, 10 with circumferential approach and one with XLIF + Lateral Plating

• In 3 cases stand alone XLIF + posterior decompression without instrumentation

• 31 out of 37 patients completed the FU and were enrolled for the study• 21 patients single level procedure, 10 patients double level procedure

livelli trattati

L1-L2L2-L3L3-L4L4-L5L1-L2/L2-L3L2-L3/L3-L4L3-L4/L4-L5

Diagnosis on admission

imaging

DDDDDD + stenosisDDD + DH

Symptoms

BPBP + RP

Stand alone XLIF: results after 3-months FU

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Stand alone XLIF: results after 3-months FU

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Stand alone XLIF: results after 6-months FU

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Stand alone XLIF: results after 6-months FU

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Results analysis

• Most cases show good outcome with progressive improvement at six month FU

• Unmodified or worsened ODI and VAS scores are classified as poor outcome

• Limited improving of scores at three-six months FU that doesn’t lead to category shifting is considered as no satisfactory (poor outcome)

• After 3 months FU, 4 out of 9 patients did not significantly improve; of these, three had limited improvement but didn’t change ODI category, one had bad outcome with ODA/VAS scores worsening.

• After six month, 1 out of 22 patients didn’t improve significantly• Data matching at three and six months shows progressive outcome

improving

Stand alone XLIF: pitfalls• Radiological study at three and six months with lateral Flexion-Extension X-

Rays didn’t show significant bone formation• 8 out of 23 patients (34,8%) showed radiological evidence of subsidence of

the cage at six months FU• 3 out of 9 patients (33%) showed radiological evidence of subsidence of the

cage at three months FU• 7 out of 11 cages were 18 mm wide.• Subsidence was identified in one case of poor outcome at three month FU

(22mm CoRoent XL)• No subsidence in the case of poor outcome after 6-months FU• In 10 cases subsidence was clinically silent

Poor outcome analysis• Back pain in three cases, back pain + radiculopathy in 2 cases• Subsidence in one case (BP + RP)• Single level (L3-L4) interbody fusion in two levels degenerative disc

disease (L3-L4/L4-L5): procedure aborted in L4-L5.• Persistent foraminal stenosis in one case• No clear causes of persistent symptoms in two cases

Stand alone XLIF: implant failure

• GR, female, 66 Years-old, previous L4-L5 PL arthrodesis in L5-S1 grade two spondylolishtesis, osteoporosis

• Symptoms: invalidating low back pain, lower limbs radicular pain with cladicatio spinalis, walking severely restricted

• Clinical examination on admission: segmental paresis in extension of left foot, Lasegue + 40° in left lower limb

• Pre-op LS MRI: L5-S1 grade II spondylolisthesis with spontaneous fusion, L4-L5 pedicle screws with left L5 screw malposition, adjacent level discopaty with Modic 1 changes of the endplate, right convex scoliosis with L3-L4 apex.

• Surgical planning: L3-L4 stand alone XLIF to achieve mild coronal deformity correction and treat adjacent level discopathy, L4-L5 laminectomy to decompress left L5 nerve root

Peri-operative complications

• Right side surgical approach with MAXcess, standard fashion discectomy, 18x55x8 mm parallel trial followed by 18x50x10 mm parallel trial then 22x50x10 mm lordotic trial

• No evidence of subsidence during the discectomy and trial introduction, but significant bleeding from the disk space started after last steps

• Cage dislocated in the cranial third of L4 vertebral body (22x50x10 lordoticl); bleeding stopped just after cage insertion, the implant was tightly positioned in the L4 body

• We decided to leave the implant there and go on with posterior decompression

Stand alone XLIF