Mayo Elbow Performance Index

Introduction

The Mayo Elbow Performance score (MEPS) or Mayo Elbow Performance Index (MEPI) is an instrument used to test the limitations, caused by pathology, of the elbow during activities of daily living (ADL) . This specific test uses 4 subscales:

1. Pain,
2. Range of Motion (arc of motion of the art. humeroulnaris)
3. Stability
4. Daily Function

MEPS can be used to measure which treatment work best for different conditions, An example would be when deciding the best post-operative treatment for example: the difference in prognosis between open and closed fractures when operated.

Clinically Relevant Anatomy

The elbow is an articulation between the humerus in the upper arm and the radius and ulna in the lower arm. The art. humeroulnaris connects the humerus and the ulna and allows flexion and extension in the elbow. Assessing movement is a key factor in the MEPI and has its own subscale.

Muscles responsible for movement at the elbow and the forearm can be divided into four groups: the flexors, the extensors, the pronators and the supinators.

• Flexors: Biceps, Coracobrachialis, Brachioradials, Brachialis, Pronator Teres, flexors of the wrist
• Extensors: Triceps, Anconeus, Supinator
• Pronators: Pronator Teres,Pronator Quadratus, Brachioradialis
• Supinators: Supinator, Brachioradialis, Biceps
  

Technique

MEPS is a 4 part test where clinical information is rated based on a 100 points scale.

• <60 - poor
• 60-74 – fair
• 75-89 - good
• 90-100 – excellent

Part 1: Pain

The therapist asks the patient how severe the pain is and in how frequent the pain appears.

• 45 points are for patients who do not have pain,
• 30 points are given to patients who have mild pain,
• moderate pain results in 15 points,
• patients with severe pain get 0 points.

Part 2: Range of motion

The patient starts with his elbow fully extended and then tries to flex the elbow.

• 20 points are given when the arm reaches more than 100° flexion,
• 15 points If the angle is between 100°-50°
• 5 Points when the elbow bends 50° or less

Part 3: Stability

• When the elbow is considered stable 10 points are given.
• A mildly unstable elbow results in 5 points.
• An unstable elbow does not receive points (0).

Part 4: ADL

Based on 5 ADL’s who are each given 5 points an image is sketched how well the patient is able to participate in the daily life. The activities are:

• Combing your hair
• Performing personal hygiene
• Eating
• Putting on shirt and shoes.

Variations of the Index

Mayo elbow performance index has 2 variants. The first one excludes function and ADLs; it has just 3 criteria pain, range of motion and stability and is used for comparison between pre – and postoperative results with patients who had a Kudo elbow prosthesis. The prosthesis was placed as a treatment for rheumatic arthritis. The points are added up and put on a 100 points scale with norms equal to the standard test.

In the second variant of the MEPI the the ADL is removed and replaced with a strength category. The following adaptions are also made:

• The factor pain is rated at a scale of 40 with 40 no pain and 0 for greatest pain ever, the way rating is the same as for normal test.
• Both stability and arc of motion are rated equal to the standard MEPI.
• The strength is measured on clinical rating scale
  • 20 for normal strength over
  • 14 for mild loss of strength
  • 7 for moderate loss of strength
  • 0 for marked loss of strength.

The results are graded with a maximum of 100 points and categorised into 4 groups:

• 91- 100: excellent
• 90 – 81: good
• 80 – 71: fair
• <70: poor

Evidence

Turchin et al. described the MEPS a: “The Mayo elbow-performance index as having a clear format. The associated costs were low because only a goniometer was necessary. Little training was needed, and the system was suitable for use in a clinic. Neither strength nor deformity was included in the content of the scale, and motion was assessed only in terms of flexion and extension. The scaling was ordinal and seemed appropriate. Function and motion were weighted less heavily than pain.”

Mayo Elbow Performance Index often appears in scientific documentation as a golden standard for questionnaires, to measure improvement after surgery, to compare treatments or conditions and as an indication for therapy. Nevertheless Longo et al. concluded that further research is necessary to document validity and sensitivity of a lot of elbow tests including the MEPS and only one study was found where MEPS was really tested. This study showed that the correlation with the other tests (Broberg and Morrey, Ewald et al, The Hospital for Special Surgery and Pritchard) was high but the correlation with a visual analogue scale was only moderate. A study in 2014 concluded that MEPS has strong reliability when assessed at different times and when compared with a validated elbow outcomes instrument, although the study was small and had only 42 participants.