TABLE 4.
Comparison of Individual Patients’ Grade of Postoperative Atrophy and Their MHHS and Hip Flexor Strength at the Time of Their Second MRAa
| ID | Age, y | Sex | Grade of Atrophyb | Preop MHHS | Time to MRA 2, mo | Hip Score at MRA 2 | Strength at MRA 2c |
|---|---|---|---|---|---|---|---|
| 19 | 16 | F | 4 | 38.5 | 10 | 82.5 | 5 |
| 23 | 17 | F | 4 | 45.1 | 41 | 81.4 | 5 |
| Mean | 16.5 | 41.8 | 81.95 | ||||
| 17 | 25 | F | 3 | 46.2 | 8 | 45.1 | 4 |
| 22 | 39 | F | 3 | 39.6 | 11 | 81.4 | 4 |
| 10 | 20 | F | 2 | 72.6 | 39 | 84.7 | 5 |
| 20 | 42 | F | 2 | 41.8 | 5 | 59.4 | 4 |
| 26 | 29 | F | 2 | 59.4 | 10 | 68.2 | 5 |
| 27 | 31 | F | 2 | 50.6 | 24 | 79.2 | 5 |
| 30 | 33 | F | 2 | 45.1 | 11 | 56.1 | 5 |
| 32 | 26 | F | 2 | 41.8 | 20 | 67.1 | 4 |
| Mean | 30.6 | 49.6 | 67.6 | ||||
| 3 | 20 | F | 1 | 38.5 | 3 | 81.4 | 5 |
| 6 | 35 | F | 1 | 39.6 | 32 | 47.3 | 4 |
| 9 | 15 | F | 1 | 45.1 | 41 | 84.7 | 5 |
| 12 | 50 | F | 1 | 33.0 | 31 | 72.6 | 4 |
| 13 | 39 | F | 1 | 45.1 | 11 | 81.4 | 5 |
| 14 | 21 | M | 1 | 57.2 | 36 | 81.4 | 5 |
| 15 | 24 | M | 1 | 42.9 | 12 | 42.9 | 4 |
| 18 | 44 | F | 1 | 53.9 | 10 | 35.2 | 4 |
| 21 | 30 | F | 1 | 41.8 | 6 | 49.5 | 3 |
| 24 | 18 | F | 1 | 59.4 | 23 | 91.3 | 5 |
| 25 | 56 | F | 1 | 38.5 | 5 | 56.5 | 3 |
| 29 | 49 | F | 1 | 39.6 | 3 | 46.2 | 4 |
| 31 | 32 | F | 1 | 29.7 | 19 | 33 | 3 |
| 33 | 38 | F | 1 | 23.1 | 6 | 53.9 | 4 |
| 34 | 31 | F | 1 | 44 | 5 | 73.7 | 5 |
| 5 | 35 | M | 0 | 57.2 | 15 | 69.3 | 5 |
| 7 | 41 | F | 0 | 38.5 | 24 | 90.2 | 5 |
| 11 | 26 | F | 0 | 41.8 | 3 | 63.9 | 4 |
| Mean | 33.6 | 42.7 | 64.1 |
aThere was no significant difference in the average scores of the 18 patients with mild (grades 0-1) and the 8 patients with moderate (grades 2-3) postoperative iliopsoas atrophy (P = .64). Hip flexor strength testing at the time of the second MRA indicated that there was no correlation with a patient’s hip flexor strength and the grade of muscle atrophy observed on their postoperative MRA. F, female; M, male; MHHS, modified Harris Hip Score; MRA, magnetic resonance arthrography.
bHighest grade of atrophy observed in the iliacus and/or psoas muscles.
cMaximum active hip flexion strength was determined for both hips with patient seated at the end of the examining table. Each patient was then instructed to forcibly flex his or her hip against the manual muscle resistance applied by the examiner (senior author), who rated the strength from 0-5 based on the manual muscle testing scale.