[Retracted] The Percutaneous Endoscopic Lumbar Debridement and Irrigation Drainage Technique for the First-Stage Treatment of Spontaneous Lumbar Spondylodiscitis: A Clinical Retrospective Study

Table 1

Pola classification criteria.

Type A without biomechanical instability neither acute neurological impairment or epidural abscesses	Type B with radiological evidence of significant bone destruction or biomechanical instability without acute neurological impairment or epidural abscesses	Type C with epidural abscesses or acute neurological impairment
A1: simple discitis without the involvement of vertebral bodies	B1: destructive spondylodiscitis without segmental instability	C1: epidural abscess (+), neurological impairment (-), segmental instability (-)
A2: spondylodiscitis involving the intervertebral disc and adjacent vertebral bodies	B2: destructive spondylodiscitis extended to paravertebral soft tissues without segmental instability	C2: epidural abscess (+), segmental instability (+), neurological impairment (-)
A3: spondylodiscitis with limited involvement of paravertebral soft tissues	B3: destructive spondylodiscitis with biomechanical instability and segmental kyphosis ()	C3: epidural abscess (+), neurological impairment (+), segmental instability (-)
A4: spondylodiscitis with unilateral or bilateral intramuscular abscesses		C4: epidural abscess (+), neurological impairment (+), segmental instability (+)