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 Policy 18-05-03, Determining the Degree of Permanent Impairment 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 result from incidents that arise out of and in the course of employment.
  • Decision-makers will gather relevant information and weigh evidence to make adjudicative decisions.
  • Work-relatedness is established when determining initial entitlement. Decision-makers continue to evaluate the work-relatedness of a person’s ongoing impairment throughout the life of a claim.
  • A work-related impairment is considered permanent when it continues to exist after maximum medical recovery has been reached.
  • Someone who has a permanent work-related impairment is entitled to a non-economic (NEL) benefit based on the degree of their work-related impairment, as determined by the WSIB.

Introduction

When someone’s work-related injury or illness has reached maximum medical recovery (when the injured or ill person has reached a plateau in recovery and it is not likely that there will be any further significant improvement in the work-related injury/illness) and there is clinical evidence of ongoing impairment resulting from the work-related injury or illness, they are considered to have a permanent work-related impairment. The Workplace Safety and Insurance Board (WSIB) must then determine the degree of the work-related permanent impairment (PI) and the person’s entitlement to non-economic loss (NEL) benefits.

Section 18(1) of Ontario Regulation 175/98 under the Workplace Safety and Insurance Act, 2007 (WSIA) prescribes the rating schedule the WSIB must use to determine the degree of the PI resulting from a work-related injury or illness. The prescribed rating schedule is the American Medical Association Guides to the Evaluation of Permanent Impairment, Third Edition (Revised) (the AMA Guides). Where the prescribed rating schedule does not provide for an impairment, the regulation directs the use of criteria in the prescribed rating schedule for the body parts, systems, or functions which are most analogous to the person’s impairment (O.Reg. 175/98 s.18(2)).

Determining the degree of someone’s work-related PI is the responsibility of decision-makers in the WSIB’s Permanent Impairment (PI) Program. Decision-makers in the PI Program are guided by relevant policies, including Policy 18-05-03 Determining the Degree of Permanent Impairment, the AMA Guides, and all health care information in the claim file. In rare circumstances where the injured or ill person’s physician or other health care professional involved in the case cannot provide sufficient information to determine the degree of the person’s PI, the WSIB may arrange for the person to attend an independent medical assessment.

Where the AMA Guides do not provide for an impairment and there is no close analogy, or where application of the prescribed rating schedule would result in an unfair assessment of the person’s impairment, the WSIB has established Rating Guidelines for determining the degree of the impairment in these cases.

This document outlines the WSIB’s Rating Guidelines for determining the degree of PI for:

  • Acromioplasty
  • Repetitive strain injuries (RSIs) of the upper extremity (shoulder, arm, forearm, wrist and hand) and lower extremity (hip, thigh, leg, ankle and foot)
  • Splenectomy

Acromioplasty

The AMA Guides do not provide a percentage value for the rating of surgeries to the acromioclavicular (AC) joint. While the glenohumeral (GH) joint is in fairly close proximity anatomically to the AC joint, it is a much larger joint, has significantly different function and surgery to the GH joint is generally much more invasive than surgery involving the AC joint. For these reasons, using the GH joint as an analogy to the AC joint would be inaccurate, as the percentage rating over-estimates functional contribution and  the extent of surgery. A review of Tables 17 and 19, (pg. 48 and 50) from the AMA Guides does not reveal any other upper extremity joint disorder or surgery which could be used as an accurate analogy in reference to the AC 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 (pg. 52).  In the absence of a closer analogy for rating AC joint surgeries, the WSIB established the following rating guideline to promote consistency and fairness in the rating of surgeries to the AC joint.

Rating guideline

Acromioplasty

Acromioplasty is often undertaken to enlarge the space between the acromion and humerus, thereby resulting in decompression of a portion of the rotator cuff.

Using a discretionary rating, an acromioplasty, including distal clavicle resection, will be rated at 10 per cent for the upper extremity impairment. This value would be combined with other impairment values, such as range of motion loss and would then be reduced to a whole person impairment (WPI) percentage as required by s. 47(1) of the WSIA and in accordance with 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 GH joint will be rated at 12 per cent for the upper extremity impairment. This would also be combined with other impairment values and then reduced to a whole person impairment (WPI) percentage. Examples would include surgeries which may be performed for shoulder instability, such as Putti Platt or Bankhart lesion repairs.

Glenohumeral surgeries

This rating would be reserved for a surgery in which the GH joint undergoes major alteration. As per the AMA Guides, a 24 per cent rating is given for the upper extremity impairment for resection arthroplasty of the GH joint. The 24 per cent upper extremity impairment would exclude the less invasive surgeries such as debridement of the GH joint.  For an implant arthroplasty, a 30 per cent rating for the upper extremity impairment is given. 

Again, the percentage ratings for these surgeries would be combined with other impairment values and reduced to a WPI percentage, in accordance with the AMA Guides.

Repetitive Strain Injuries

Work-related repetitive strain injuries (RSIs) result from overuse of specific parts of the body, both upper and/or lower extremities. There are four major risk factors, alone or in combination, that have been identified as contributing to or increasing the likelihood of developing a RSI.  These risk factors may include:

  • awkward or static posture        
  • repetition
  • force
  • vibration

The AMA Guides indicate that to determine the degree of permanent impairment resulting from RSIs, the injured person should have worked for six to eight hours at the job that led to the RSI prior to attending a medical assessment. The expectation is that after having used the extremity for this prescribed period of time, the assessment would more accurately capture the resulting symptoms. However, noting the diverse and unique situations of injured people and employers, as well as scheduling issues with health care professionals, such an arrangement is generally not viable or realistic. Therefore, if the injured person attends a medical assessment(s) without having used the extremity for a prolonged period of time, or just if the limb has not been active, there is a possibility that rating parameters, such as a decrease in range of motion may be within normal limits.  

According to the AMA Guides, the degree of impairment in these cases would be 0 per cent.

In non-surgical cases where the clinical findings show normal range of motion, the following rating guideline is used to ensure consistency and fair recognition of permanent impairment for RSIs for both upper and lower extremities.

Rating guidelines

The two charts below outline the considerations for rating upper extremities and lower extremities.  Each chart provides the categories of assessment and the prescribed percentage to be awarded, depending on the impact in each of the categories.  Each category has a specified range and is subject to a maximum percentage.  The charts also outline the maximum for the extremity and the corresponding percentage of the whole person. 

RSI rating for upper extremity (UE)

Clinical findings  
  • Swelling
  • Pain and tenderness
  • Scarring (if surgical history)
  • Decreased range of motion
  • Inflammation
  • Muscle wasting
Range 0-3 per cent (maximum 3 per cent for UE)
History  

Current functional disorder as a result of the RSI

Range 0-1 per cent (maximum 1 per cent for UE)
Treatment  

Example of past or present ongoing treatment

  • Steroid injections
  • Physiotherapy
  • Analgesic/anti-inflammatory medication
  • Splints/tensors
  • Braces/supports
  • Surgery
Range 0-2 per cent (maximum 2 per cent for UE)
Activities of daily living (ADL)  
  • Difficulties with basic function (e.g., self-care/personal hygiene/sleep)
  • Regional functions are impaired (e.g., hand dominance of affected limb/joint)
  • Interactive activities are impaired (e.g., social/leisure)
Range 0-3 per cent (maximum 3 per cent for UE)
Total Maximum of 9 per cent for UE = 5 per cent WPI

Where an RSI affects multiple levels of the same upper limb (for example, shoulder, elbow, and wrist), or the same lower limb (for example, hip, knee and ankle), clinical findings are rated for each of the impaired levels. The history, treatment and ADL categories are rated once for the whole upper or lower limb, as applicable.

RSI rating for upper extremity (LE)

Clinical findings  
  • Swelling
  • Pain and tenderness
  • Scarring (if surgical history)
  • Decreased range of motion
  • Inflammation
  • Muscle wasting
Range 0-2 per cent (maximum 2 per cent for LE)
History  
Current functional disorder as a result of the RSI Range 0-1 per cent (maximum 1 per cent for LE)
Treatment  

Example of past or present ongoing treatment

  • Steroid injections

  • Physiotherapy
  • Analgesic/anti-inflammatory medications 
  • Splints/tensors
  • Braces/supports
  • Surgery
Range 0-2 per cent (maximum 2 per cent for LE)
Activities of daily living (ADL)  
  • Difficulties with basic function (e.g., walking, climbing, squatting, prolonged standing)
  • Regional functions are impaired (e.g., decreased strength and stability of affected limb/joint)
  • Interactive activities are impaired (e.g., social / leisure)
Range 0-3 per cent, (maximum 3 per cent for LE)
Total Maximum of 8 per cent for  LE = 3 per cent WPI

Splenectomy

A splenectomy is the medical term given for the surgical removal of the spleen, a highly vascular organ in the upper abdomen which is part of the lymphatic system and has an important immunologic function, helping the body to fight infection. For WSIB purposes, the most common cause of an injury causing a spleen to be removed is a blunt force trauma or a penetrating wound to the abdomen or chest.

The AMA Guides states the impairment following surgery to remove the spleen is rated at 0 per cent.

Rating guideline

The AMA Guides allows for a PI rating for ongoing monitoring and/or prophylactic treatment, which is recognized as essential post-operative care for monitoring a condition.

The nearest and most accurate analogy to rate this impairment is found in Chapter 7: The haematopoietic system section 7.4 of the AMA Guides.

Although the AMA Guides specifically states that the actual surgical procedure is given a 0 per cent, the class 1 (0-10 per cent) has the following criteria:

  1. There are symptoms of leukocyte abnormality;
  2. No frequent treatment is needed;
  3. All or most of the activities of daily living can be performed

In this situation, it is reasonable to use these criteria as it is the nearest analogy.  It is reasonable to recognize the life-long increased risk of infection and the antibiotic prophylactic treatment recommended by evidence-based practice guidelines for this condition.

If the individual is asymptomatic at the time of the rating, a 5 per cent rating is given in recognition of the potential complications following spleen removal that include a long-term risk of various infections. This recognizes a PI is evident when a spleen has been removed because of the need for prophylactic treatment due to alterations to the immune system function.

Conclusion

Someone who has a PI resulting from a work-related injury or illness is entitled to a non-economic loss (NEL) benefit based on the degree of their work-related impairment, as determined by the WSIB. When determining the degree of the impairment, decision-makers in the PI Program are required to use the American Medical Association Guides to the Evaluation of Permanent Impairment, Third Edition (Revised), (the AMA Guides), as prescribed by O.Reg. 175/98.

The WSIB has identified circumstances (acromioplasty, RSI injuries and splenectomy) where application of the AMA Guides would result in an unfair assessment of the person’s impairment.  Therefore, the WSIB has established rating guidelines for these special circumstances to ensure fair and consistent recognition of a work-related PI, and appropriate NEL benefits to injured or ill people.

Document history:

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)

Reviewed December 2020

Scheduled review:  December 2025