Learning SIGMD for Spinal Assessment

Have you read the Spinal Impairment Guides Modification Document (SIGMD)? If not, this is a must! This article will provide a more detailed description of the SIGMD methodology of spinal assessment. The SIGMD was published in the Victorian Government Gazette on 6 October 2016 (Special Gazette, No. S 305) Spinal Impairment Guides Modification Document (SIGMD) for TAC clients who suffered injuries to their spine after 14 December 2016.

A/Prof Cristina Morganti-Kossmann

Lex Medicus Publishing Director

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Medico-legal spinal assessment
Have you read the Spinal Impairment Guides Modification Document (SIGMD)? If not, this is a must! As follow up of the breakfast seminar presented by Mr Thomas Kossmann on the SIGMD legislation, Lex Medicus is proud to release a second article to whet your appetite.
This article will provide a more detailed description of the SIGMD methodology of spinal assessment.

Spinal assessment

 

The SIGMD was published in the Victorian Government Gazette on 6 October 2016 (Special Gazette, No. S 305) Spinal Impairment Guides Modification Document (SIGMD) for TAC clients who suffered injuries to their spine after 14 December 2016.
The following document acknowledges the Spinal Impairment Guides Modification Document (SIGMD) as the major source of information.

 

The main SIGMD changes

  • The Spinal Impairment Guides Modification Document (SIGMD) affects TAC clients who suffered injuries to the spine after 14 December 2016.
  • The SIGMD legislation does not apply to WorkSafe Vic or the Wrongs Act. It is actually unlawful to use it for other claims.
  • It only applies to spinal assessments for claims where the date of accident is 14 December 2016 or later.

 

IMPORTANT DEFINITIONSplease see:

• Definition of fracture (see Definitions SIGMD 3.4)
Cortical breach of bone,
– and does not include minor pathology such as bone bruising or micro trabecular fracture (or like conditions) that are seen or implied only on MRI or nuclear scanning.

• Definition of fracture of laminectomy and laminotomy (see Definitions SIGMD 3.7) 
References to spinal decompression surgery involving the lamina – the terms are often used interchangeably
– laminectomy being the complete removal of the lamina or adjacent laminae,
– laminotomy being the partial removal of the lamina or adjacent laminae;
• Definition of minor spinal procedures (see Definitions SIGMD 3.8)
Spinal procedures at the cervical, thoracic and lumbar spine are assessed according to SIGMD as DRE category I (0% Whole Person Impairment).
– injection,
– vertebroplasty performed by needle,
– a percutaneous spinal procedure (other than discectomy, laminectomy or laminotomy)
– implantation of a spinal cord stimulator and /or drug delivery system as well as similar minor spinal procedures.
• Definition of Posterior or like element means: (see Definitions SIGMD 3.9)
a) a posterior part of a vertebra, which forms part of the bony protective ring around the spinal canal, including a pedicle, a lamina, a pars interarticularis, a superior articular process and facet and an inferior articular process and facet, but does not include a transverse process or spinous process or a transverse foramen;
b) the occipital condyle;
c) the dens, lateral mass or other atypical bony structures of C1 and C2, which form the bony protective ring around the spinal canal, but does not include a transverse process or spinous process or a transverse foramen;

 

Spinal assessments regions

• The occipital condyle is included in the cervicothoracic (cervical) region, which comprises the C1-C7 vertebrae and motion segments C0-C1 to C7-T1, inclusively.

• The thoracolumbar region includes the T1 to T12 vertebrae and the motion segments T1-T2 to T11-T12.

• The lumbosacral region includes the L1 to L5 vertebrae and the motion segments T12-L1 to L5-S1.

• The sacrum is not assessed under the SIGMD spine but as part of the impairment of the pelvis. (see Chapter 3.4, page 3/131 of AMA Guides 4th edition)

Particular Fractures (see Definitions SIGMD 3.8)
– A fracture of C7 is assessed as an impairment in the cervicothoracic region.
– A fracture of T1 is assessed as an impairment in the thoracolumbar region.
– A fracture of T12 is assessed as an impairment in the thoracolumbar region.
– A fracture of L1 is assessed as an impairment in the lumbosacral region.

 

Rules for SIGMD spinal impairment

• Please read carefully Spinal Impairment Guides Modification Document (SIGMD) 6.1 to 6.10

SIGMD differentiates if there are conditions affecting

a. Single vertebra       –   Column 1
b. Multiple vertebrae     –   Column 2
c. Surgical procedure     –   Column 3• An impairment can only be awarded if the relevant descriptor is strictly satisfied. Please see the descriptors in the respective columns.
A typical example is mentioned in 6.3.6, page 5, of the Victoria Government Gazette No. S 305.• The assessment of spinal cord damage must be undertaken using either the methodology for the relevant spinal assessment region in Section 3.3 of Chapter 3 (‘The Spine’) or in Chapter 4 (‘The Nervous System’) of the Guides. The spinal impairment assessed under Chapter 4 of the Guides cannot (unless where permitted) be combined with impairment assessed for the relevant spinal assessment region from Section 3.3 of Chapter 3 of the Guides or under the SIGMD Guidelines. The method, which is providing the greater impairment percentage for the spinal cord damage is the appropriate assessment.

• For bladder and bowel impairment estimates, please seek further information in the respective  Guides chapters on the digestive and urinary and reproductive systems.

• The total spine impairment score is the score, in which each individual spine region assessment is combined using the combined values calculator. (www.iatvic.com.au)

Revised tables

• Tables from the Guides have been revised
Table 70         —-       R-70
Table 72         —-       R-72
Table 73         —-       R-73
Table 74         —-       R-72

 

Examples of spinal assessments under SIGMD legislation for TAC patients:

Case No 1:

Spinal assessment - x-ray

A 45-year-old car driver t-boned a car at high speed on 24 December 2016. He reports being thrown forward violently and consequently, he hits the steering wheel. He complained of severe pain in his cervical spine. He had some minor cuts and bruises in his face, which healed without scars. He presented no neurological signs but ongoing pain. He underwent x-rays and CT scans, which did not show any fracture(s).

The initial MRI of the cervical spine showed micro trabecular fractures at C5, C6 and C7 and disc protrusions at the C5/6 and C6/7, affecting the respective nerve roots.
He was initially treated conservatively with a collar. However, he had enduring pain. The MRI showed disc bulges at the C5/6 and C6/7 levels. After a consensus conference, he underwent a two-level fusion at the C5/6 and C6/7.

Following the operation, his condition improved and 6 months later he underwent an impairment assessment. He presented a visible scar of 6 cm on the right side of the neck.

According to Table A, SIGMD page 16:

DRE Category IV, Column 3:
“Multilevel surgical stabilisation, fusion or disc replacement with or without signs of radiculopathy as defined for Table A”

Permanent impairment in accordance with the AMA Guides 4th Edition, modified according to SIGMDSITE                     FIG. TABLE      PAGE                 IMPAIRMENT                                     WPI %


Cervical spine    R-73                  13, SIGMD         DRE Cervicothoracic Category 4        25%
Scarring              2                        13-280                                                                                3%


 

DRE Cervical Spine Impairment: 27% Whole Person Impairment (combined with scarring either according to Combing Values Chart Page 322, 4th edition of the AMA guides or using the combined values calculator. (www.iatvic.com.au)).

 

AMA4 guides combined values calculator

 

Case No 2:

aggravation of the lumbar spondylosis without fracture

 

A 65-year-old woman was hit by a car while riding a bicycle on 1 January 2017. She fell off the bicycle and complained about pain in the lumbar spine. At the consultation, she did not present with any neurological symptoms. Prior to the accident, x-rays and CT scans of the spine showed degenerative changes of the facet joints in the lumbar spine. The investigation found an aggravation of the lumbar spondylosis without fracture. She was referred for bilateral medial branch blocks at the L3/4/5 levels, which provided some pain relief.

The described lumbar spine pathology is evaluated using Table R 72 page 12, SIGMD, Victoria Government Gazette No. S 305 and Table A page 15.

 

According to Table A, SIGMD page 15:
DRE Category 1, Column 3: “One or more minor spinal procedure”

Please see: Definition of minor spinal procedures (SIGMD 3.8): spinal procedures at the cervical, thoracic and lumbar spine are assessed according to SIGMD as DRE category I = 0% Whole Person Impairment.
– injection,
– vertebroplasty performed by needle,
– a percutaneous spinal procedure (other than discectomy, laminectomy or laminotomy)
– implantation of a spinal cord stimulator and /or drug delivery system as well as similar minor spinal procedures.

 

Permanent impairment in accordance with the AMA Guides 4th Edition, modified according to SIGMD

SITE                     FIG. TABLE     PAGE              IMPAIRMENT                                 WPI %


Lumbar spine      R-72                   12, SIGMD      DRE Lumbosacral Category 1           0%


DRE Lumbar Spine Impairment: 0% Whole Person Impairment.

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