Ankylosis of the Thumb — VA Disability Rating Criteria (DC 5224)
Diagnostic Code 5224 · 38 CFR §4.71a
What Is It?
DC 5224 is the individual-digit code for ankylosis of the thumb — the thumb fixed, with no motion at the joint, while the other four digits are not ankylosed. The schedule gives it two rows: unfavorable ankylosis at 20 percent and favorable ankylosis at 10 percent. Both figures are the same in the major and the minor column, so unlike the multiple-digit codes above it, handedness does not change the evaluation here. Which row applies is decided by joint position, and 38 CFR 4.71a defines it for the thumb specifically. If both the carpometacarpal and the interphalangeal joints are ankylosed, the ankylosis is unfavorable even where each joint is individually fixed in a favorable position. If only one of those two joints is ankylosed, the test is a measurement: a gap of more than two inches (5.1 cm) between the thumb pad and the fingers, with the thumb attempting to oppose them, is unfavorable, and a gap of two inches or less is favorable. There is a third outcome that pays more than either row. Where both the carpometacarpal and interphalangeal joints are ankylosed and either is in extension or full flexion, or there is rotation or angulation of a bone, the schedule directs that the thumb be evaluated as amputation at the metacarpophalangeal joint or through the proximal phalanx — DC 5152, which is 30 percent on the major hand and 20 on the minor. That instruction is in the Notes to this part of 38 CFR 4.71a, and it is the most valuable sentence on this page. If a second digit is ankylosed as well, this code stops applying and the two-digit code takes over: DC 5219 for unfavorable ankylosis of two digits, at 40 or 30 percent where the thumb is one of them, and DC 5223 for favorable ankylosis, at 30 or 20. The Note under each of the individual-digit codes is longer than the one under the multiple-digit codes: also consider whether evaluation as amputation is warranted, and whether an additional evaluation is warranted for resulting limitation of motion of other digits or interference with overall function of the hand. Running the other way, 38 CFR 4.68 caps the combined rating for disabilities of one extremity at the evaluation for amputation at the elective level.
Rating Criteria
| Rating | Criteria |
|---|---|
| 20% | Unfavorable ankylosis of the thumb — either hand. The schedule lists 20 percent in both the major and the minor column. |
| 10% | Favorable ankylosis of the thumb — either hand. The schedule lists 10 percent in both columns. Note to the table: also consider whether evaluation as amputation is warranted, and whether an additional evaluation is warranted for resulting limitation of motion of other digits or interference with overall function of the hand. |
Evidence Needed
- Range of motion testing at the carpometacarpal, metacarpophalangeal and interphalangeal joints of the thumb, in degrees, showing zero motion. Ankylosis is the absence of motion; limited motion of the thumb is DC 5228 and it pays differently.
- Which of the thumb's joints are ankylosed. Both the carpometacarpal and the interphalangeal joint being fused makes the ankylosis unfavorable by definition under 38 CFR 4.71a.
- Where only one of those joints is fused, the measured gap between the thumb pad and the fingers with the thumb attempting to oppose them. More than two inches is unfavorable, two inches or less is favorable, and that measurement is the whole difference between 20 percent and 10.
- Whether either ankylosed joint is fixed in extension or in full flexion, or whether there is rotation or angulation of a bone. Those findings send the evaluation to the thumb amputation code, DC 5152, which pays more.
- Whether any other digit on the same hand is ankylosed. A second ankylosed digit moves the claim to the two-digit codes, DC 5219 or DC 5223.
- A functional account of what the hand can no longer do — pinch, grip, buttons, keys, tools — and of any limitation of motion in the digits that still move.
- Service treatment records covering the original injury, plus operative reports for any fusion or reconstruction.
C&P Exam Tips
- Ask the examiner to record zero degrees at each named thumb joint rather than describing the thumb as "fixed."
- Ask that the gap between the thumb pad and the fingers be measured with the thumb attempting to oppose them, and written down in inches or centimetres. That measurement is what separates the 20 percent row from the 10 percent row.
- Have the position of each ankylosed joint described — in particular whether either is in extension or full flexion, and whether there is any rotation or angulation of a bone. Those findings route the evaluation to the amputation code.
- Ask whether evaluation as amputation is warranted, which is what the Note to this code directs.
- Report whether the fixed thumb interferes with the motion of the fingers, and ask that any limitation of those digits be measured; the Note contemplates an additional evaluation for that interference.
- Bring the objects you struggle with, and demonstrate the pinch and grasp tasks that fail.
- Mention grip and pinch strength testing if it was done, and ask for it if it was not.
- Describe what the other hand has taken on. Overuse of the sound side is a common and claimable consequence.
How to File
File for ankylosis of the thumb and name the joints that are fused. Both figures under this code are the same on either hand, so handedness is not the variable here — the position of the fused joints is. Provide range of motion findings showing zero degrees, a statement of which joints are ankylosed, and the measured gap between the thumb pad and the fingers where only one joint is fused, because that measurement is what separates 20 percent from 10. Ask in the claim that evaluation as amputation be considered: where both the carpometacarpal and interphalangeal joints are ankylosed and either is in extension or full flexion, or a bone is rotated or angulated, 38 CFR 4.71a directs evaluation as amputation at the metacarpophalangeal joint or through the proximal phalanx, which is DC 5152 at 30 or 20 percent. Expect 38 CFR 4.68 in the other direction: the combined rating for that extremity cannot exceed the evaluation for amputation at the elective level.
Common Mistakes
- Expecting 30 percent under this code. DC 5224 assigns 20 percent for unfavorable ankylosis and 10 for favorable, and there is no higher step inside it — a higher figure comes from the amputation route or from a second ankylosed digit.
- Assuming the dominant hand pays more. Both of this code's rows are the same in the major and the minor column.
- Treating limited motion of the thumb as ankylosis. Ankylosis is zero motion; limitation of motion of the thumb is DC 5228.
- Leaving the thumb-pad-to-fingers gap unmeasured, which is the finding that separates the two rows where only one joint is fused.
- Missing the amputation instruction. Both joints fused with either in extension or full flexion, or with rotation or angulation of a bone, is evaluated as amputation of the thumb, which pays more than either row of this code.
- Expecting special monthly compensation for the thumb itself. 38 CFR 3.350(a) lists anatomical loss or loss of use of one hand, not of digits.
Frequently Asked Questions
Is thumb ankylosis rated at 30 percent?
Not under DC 5224. The schedule assigns 20 percent for unfavorable ankylosis of the thumb and 10 percent for favorable ankylosis, the same in both the major and the minor column. A higher figure comes from a different route — evaluation as amputation of the thumb under DC 5152, or a second ankylosed digit, which moves the claim to DC 5219 or DC 5223.
Does it matter whether it is my dominant hand?
Not for this code. DC 5224 lists the same figure in both columns at each level, so handedness makes no difference. It does matter on the multiple-digit ankylosis codes, where 38 CFR 4.69 settles which hand is dominant.
How does VA tell favorable from unfavorable thumb ankylosis?
38 CFR 4.71a sets it out. If both the carpometacarpal and interphalangeal joints are ankylosed, it is unfavorable, even if each joint is individually in a favorable position. If only one of those joints is ankylosed, a gap of more than two inches between the thumb pad and the fingers, with the thumb attempting to oppose them, is unfavorable, and two inches or less is favorable.
When is thumb ankylosis rated as an amputation?
When both the carpometacarpal and interphalangeal joints are ankylosed and either is in extension or full flexion, or there is rotation or angulation of a bone. 38 CFR 4.71a directs that this be evaluated as amputation at the metacarpophalangeal joint or through the proximal phalanx — DC 5152, at 30 percent on the major hand and 20 on the minor.
What happens if another finger is ankylosed too?
The individual-digit code stops applying and the two-digit codes take over. Unfavorable ankylosis of the thumb and any finger is DC 5219 at 40 percent major and 30 minor; favorable ankylosis of the same pair is DC 5223 at 30 and 20.