Administrative practice document: Permanent impairment rating guidelines for acromioplasty, repetitive strain injuries and splenectomy

Administrative practice document: Permanent impairment rating guidelines for acromioplasty, repetitive strain injuries and splenectomy

Note: This is not a policy; it is a supplementary document to illustrate how the WSIB will administer the Workplace Safety and Insurance Act, 1997, (WSIA) and Determining the Degree of Permanent Impairment (Policy 18-05-03) in practice. If there is a conflict between this Administrative Practice Document and the WSIA and/or WSIB policy, the decision-maker will rely on the WSIA and/or WSIB policy, as the case may be.

Key principles

• People are entitled to receive benefits for injuries and illnesses that arise out of and in the course of employment.
• Decision-makers will gather relevant information and look at evidence to make decisions about the claim.
• When deciding if a person can get benefits, decision-makers determine if the injury or illness is related to their job.
• We consider a work-related impairment permanent when it is not likely the person will make further significant improvement. We provide non-economic loss (NEL) benefits to people with a permanent work-related impairment. We decide the amount of the benefit based on the level of impairment.

Introduction

Maximum medical recovery is when someone has reached a plateau in their recovery from a work–related injury or illness, and it is not likely the person will make further significant improvement. When the person reaches the maximum medical recovery for their work-related injury or illness and medical evidence shows ongoing impairment, we consider them to have a permanent work-related impairment. We determine the degree of the person’s permanent impairment and if they qualify for non-economic loss (NEL) benefits.

Section 18(1) of Ontario Regulation (O. Reg.) 175/98 of the WSIA directs the rating schedule we use to determine the degree of the work-related permanent impairment. We use the American Medical Association Guides to the Evaluation of Permanent Impairment (AMA Guides) Third Edition (revised). If the AMA Guides don’t cover a specific type of impairment, we use the criteria for the body parts, systems, or functions that are most similar to the person’s impairment (O. Reg. 175/98 s.18(2)).

WSIB decision-makers decide the degree of permanent impairment a person has. They follow all relevant policies, including Determining the Degree of Permanent Impairment (Policy 18-05-03), the AMA Guides, and consider all health care information in the claim file. If a doctor or other health care professional can’t give enough information, we may ask the person to have an independent medical assessment (WSIA s. 47 (3)), but this is rare.

If the AMA Guides don’t cover a specific impairment and there isn’t a similar impairment, or if the standard rating method cannot be used, leading to an unfair assessment of the person’s impairment, we use our own rating guidelines to decide how much the impairment affects the person.

This document explains the WSIB’s rating guidelines for determining the degree of permanent impairment for:

• acromioplasty
• repetitive strain injuries (RSIs) of the upper and lower limbs (shoulder, arm, forearm, wrist, hand, hip, thigh, leg, ankle, and foot)
• splenectomy

Acromioplasty

The AMA Guides don’t give a percentage rating for surgeries to the acromioclavicular joint. Although the glenohumeral joint is close to the acromioclavicular joint, it is much larger, and works differently. Surgery on the glenohumeral joint is usually more complicated than surgery on the acromioclavicular joint. For these reasons, we don’t use glenohumeral joint ratings to assess surgeries to the acromioclavicular joint. Doing so would exaggerate how much surgery to the acromioclavicular joint affects function and would not fairly represent the extent of the surgery.

The AMA Guides (tables 17 and 19 on pages 48 and 50) don’t have another upper limb joint surgery that is similar to the acromioclavicular joint.

The AMA Guides do allow for a discretionary rating where the severity of the clinical findings does not correspond to the true extent of the musculoskeletal defect (page 52). Since there is no similar surgery for the acromioclavicular joint, we created a rating guideline to ensure we rate these surgeries consistently and fairly.

Rating guideline

Acromioplasty

Acromioplasty is a surgery to create more space between the acromion (a bone in the shoulder) and the humerus (the upper arm bone). This extra space helps reduce pressure on part of the rotator cuff, which can relieve pain and improve shoulder movement. Using a discretionary rating, an acromioplasty, including distal clavicle resection, will be rated at 10 per cent for the upper limb impairment. We combine this value with other impairment values, such as range-of-motion loss and then adjust the whole person impairment percentage, as required by section 47(1) of WSIA and the AMA Guides.

Other shoulder surgeries

Any shoulder surgery that meets the definition of impairment in the AMA Guides and is more invasive than an acromioplasty but does not involve major alteration of the glenohumeral joint will be rated at 12 per cent for the upper limb impairment. We also combine this percentage with other impairment ratings and then convert it to the whole body impairment. Examples of other surgeries include procedures for shoulder instability, such as Putti Platt or Bankhart lesion repairs.

Glenohumeral surgeries

If a surgery makes major changes to the glenohumeral joint, we follow the AMA Guides and assign a 24 per cent upper limb impairment rating for resection arthroplasty (removal of part of the joint). We give a 30 per cent upper limb impairment rating for a joint replacement (implant arthroplasty).

For all these surgeries, we combine the percentage ratings with other impairment values and convert it to reflect the whole body impairment, as required by the AMA Guides.

Repetitive strain injuries

Work-related repetitive strain injuries happen when a person overuses certain parts of their body, such as their arms, hands, legs, or feet. Four main risk factors can lead to or increase the risk of developing a repetitive strain injury:

• awkward or fixed positions
• repetitive movements
• using force
• exposure to vibration

The AMA Guides recommend that before assessing a permanent impairment from repetitive strain injuries, the person should work for six to eight hours at their regular job. This helps ensure the assessment accurately reflects any symptoms that appear after using that part of the body. However, most people can’t do this because of their unique situations like workplace policies, or scheduling issues with health care professionals. As a result, if someone goes to their medical assessment(s) without having used their affected part of the body for an extended amount of time, or if the limb hasn’t been active, then the results may appear to be normal.

According to the AMA Guides, the degree of impairment in these cases is zero per cent.

In cases where the examination shows normal range of motion, we use a rating guideline to ensure we are rating these injuries fairly and consistently.

Rating guidelines

The following information shows how we rate repetitive strain injuries to the arms and legs. We list the assessment categories and the percentage of impairment we can assign in each area. Every category has a set range and a maximum percentage. We also include the maximum rating for the limb and the corresponding percentage of the whole person impairment.

Repetitive strain injuries rating for the arms

If repetitive strain injury affects more than one area in the same arm (for example, shoulder, elbow, and wrist), or the same leg (for example, hip, knee and ankle), we rate each of the areas that are impacted. We only rate the history, treatment and activities of daily living categories once for the entire arm or leg.

Repetitive strain injuries rating for the legs

Splenectomy

A splenectomy is the surgical removal of the spleen. The spleen is a highly vascular organ in the upper abdomen that is part of the lymphatic system that helps the body fight infection. For workplace injuries, the most common reason for removing a spleen is an injury from a blow or a wound to the abdomen or chest.

The AMA Guides rate the impairment following surgery to remove the spleen at zero per cent.

Rating guideline

The AMA Guides provide a permanent impairment rating if someone needs ongoing monitoring or preventative treatment after surgery. We rate post-surgical impairments based on the approach described in the AMA Guides (Chapter 7: The Hematopoietic System, section 7.4).

The AMA Guides state that the rating for the surgical procedure is zero per cent. However, a person may be assigned to class one (0-10 per cent) if:

1. there are symptoms or signs of leukocyte abnormality
2. the person does not need frequent or any treatment
3. cthe person can do all or most activities of daily living

In these cases, it’s reasonable to recognize the life-long increased risk of infection and the need for ongoing antibiotic treatment, as recommended by evidence-based guidelines.

If the person has no symptoms at the time of the rating, we assign a five per cent impairment rating. This reflects the permanent risk of infection and the need for preventive treatment after spleen removal, due to changes in the immune system.

Conclusion

A person is eligible to receive a non-economic loss benefit if they have a permanent impairment from a work-related injury or illness. When determining the degree of the impairment, we use the AMA Guides, as required by Ontario Regulation 175/98.

We use our own guides when rating acromioplasty, repetitive strain injuries and splenectomy to ensure fair and consistent ratings for people with workplace injuries and illnesses.

Document history

December 2025 – Replaces December 2020 version

Reviewed December 2020

November 2015 - Replaces three adjudicative advice documents titled:

1. Permanent Impairment (NEL) Rating Guideline for Acromioplasty (March 2005)
2. Permanent Impairment (NEL) Rating Guideline for Upper and Lower Extremity Repetitive Strain Injuries (RSI) (July 2007)
3. Permanent Impairment (NEL) Rating Guideline for Splenectomy (November 2005)

Scheduled review:

December 2030