Lower Extremities Guidelines for North Carolina Workers’ Compensation Cases

Posted on Wednesday, July 27th, 2016 at 11:30 am    

These are the guidelines for doctors and physicians who have the task of determining the impairment rating for a North Carolina work injury cases. The guidelines are different than the American Medical Association guidelines. Physicians should use the North Carolina guidelines and not the AMA guidelines are their starting point.

Doctors and physicians should use their own evaluation of the patient and their own experience in making their final impairment ratings decisions.

What must be remembered is that usually, unless the employee has returned to full duty or a job paying the same or more as his or her pre-injury job, the impairment rating is seldom the most significant aspect of a seriously injured worker’s case. Many lay people get caught up in this and believe that the rating is the most important thing. It is not.

What is most important is what your doctor says about your future ability to perform work. Will you be able to return to your pre-injury job? If not, what other kind of work will you be able to do? These are usually the most important questions which will determine the value of your claim.

To see a video regarding impairment ratings generally, please click here.

General Lower Extremity Guidelines

Where a joint of the lower extremity has reparative, reconstructive surgery and a part of the joint removed or repaired with resultant osteoarthritis or traumatic arthritis anticipated, consider a minimum of 10% impairment of the joint.

Evaluation of impairment following fractures of the femur and/or the tibia and fibula is done by first evaluating any shortening and assigning impairment resulting from this; then determining the function of the adjacent joints and arriving at the impairment of these joints. The impairment is then the combined total resulting from shortening, deformity, and the impairment of the adjacent joints.

Malrotation and angulatory deformities that persist following injuries will be considered in evaluation of permanent impairment.

More Specific Lower Extremity Guidelines

  1. Shortening of Leg
Shortening      AWW Impairment to Whole Leg
·       ½ inch      4%
·       1 inch 8%
·       1½ inch 16%
·       2 inch 24%
·       2½ inch 32%
·       3 inch 40%


  1. Hip—Percentage of Impairment of Whole Leg
  • Ankylosis of the hip in optimum position (in less satisfactory position, appropriately higher percentage) = 50%
  • Arthroplasty of hip using prosthesis or cup (optimum results) = 40%
  • Limitation of motion of Hip
    • Mild Deformity = 15%

Example: AP motion: between 0 degrees and 80 degrees flexion

Lateral motion: 15 degrees adduction to 15 degrees abduction

Rotation: 20 degrees internal to 20 degrees external rotation

  • Moderate Deformity = 30%

Example: AP motion: 20 degrees flexion to 70 degrees flexion

Lateral motion: 10 degrees adduction to 30 degrees abduction

Rotation: 0 degrees internal rotation to 20 degrees external rotation

  • Severe Deformity = 60%

Example: AP motion: 30 degrees flexion to 50 degrees flexion

Lateral motion: 30 degrees adduction to 40 degrees abduction

Rotation: as much as 10 degrees internal rotation to 30 degrees external rotation

  1. Knee—Percentage of Impairment of Whole Leg
  • Ankylosis in optimum position (Ankylosis in less favorable position increasing impairment up to 90% with the knee in a non-weight bearing position) = 50%
  • Arthroplasty of knee using prosthesis or cup (optimum results) = 40%
  • Limitation of motion of Knee
    • Motion between 0 degrees to 60 degrees = 30%
    • Motion between 0 degrees to 90 degrees = 15%
    • Motion between 0 degrees to 110 degrees = 5%
    • Motion between 45 degrees to 135 degrees = 45%
  1. Ankle and Foot—Percentage Impairment of “Foot” (Leg below the Knee)
  • Ankylosis of ankle in favorable position (10 to 15 degrees equinus) with normal motion of foot = 40%
  • Ankylosis of foot (subtalar) in optimum position with normal ankle motion = 25%
  • Ankylosis in less favorable position up to = 90%
  • Ankylosis of foot and ankle (pantalar arthrodesis) in favorable position (10 or 15 degrees equinus) in neutral position of foot = 60%
  • Ankylosis of any toe = 50% impairment of the toe
  • Limitation of motion of ankle
    • Motion between 90 degrees and 120 degrees = 10%
    • Motion between 100 degrees and 115 degrees = 25%
    • Motion between 105 degrees and 110 degrees = 50%
  • Limitation of motion of foot
    • Motion of inversion of 20 degrees to eversion of 20 degrees = 10%
    • Motion of inversion of 10 degrees to eversion of 10 degrees = 20%
    • Motion of inversion of 5 degrees to eversion of 5 degrees = 40%
    • Fixed varus position = up to 90%
  • Ankylosis of subtalar joint = 25%
  • Triple arthordesis of foot = 30%
  • Displaced tarsal fractures considered as having a minimum of 5% impairment of the foot with optimum reduction. In the case of this portion of the foot, impairment is determined mainly upon the general position of the longitudinal arch and/or weight bearing position of the metatarsal heads with respect to the transverse arch rather than by evaluation of motion of the adjacent joints.

A few medical terms

Ankylosis is also known as anchyloses. It is joint stiffness due to abnormal adhesion and joint bone rigidity. It can be caused by injury or disease. The doctor will examine to see if the rigidity is partial or complete.

Arthroplasty is an orthopedic surgical procedure. It is done to relieve pain and restore joint function. In the procedure, the articular surface of a musculoskeletal joint is remodeled, replaces, or realigned.

Get a Professional North Carolina Work Injury Attorney on Your Side

The employer and the employer’s insurance company will have a lawyer fighting to terminate or minimize your benefits. You need a strong advocate that understands that small differences, such as a 20% impairment rating vs. a 10% impairment rating, could mean a significant difference in money for you. To speak with an experienced and aggressive North Carolina work injury lawyer, call for help now. Please contact North Carolina Workers’ Compensation attorney Joe Miller today at 888-694-1671 . You can also complete his contact form.