TABLE 2.
Outcomes
| Outcomes | |||
| Primary Outcome | MIPS (n = 33) | Linear Incision (n = 30) | P Value |
| Holgers index >= 2 at any time from surgery to 12 wk | 3 (9.1%) | 5 (16.7%) | 0.37 |
| Holgers index >= 2 at any time from surgery to 12 wk(Sensitivity analysis, highest observed Holgers index score plus one) | 3 (9.1%) | 5 (16.7%) | 0.37 |
| Holgers index >= 2 at any time from surgery to 12 wk(Sensitivity analysis, all implant losses have experienced Holgers index score of 4) | 7 (21.2%) | 5 (16.7%) | 0.65 |
| Secondary Outcomes | MIPS (n = 33) | Linear Incision (n = 30) | P Value |
| Wound dehiscence at 9 d | 16 (48.5%) | 22 (73.3%) | 0.078 |
| Extrusion rate | 4 (12.1%) | 1 (3.3%) | 0.19 |
| Loss of skin sensibility (mm)a | |||
| 9 d | 2.70 (6.13) 0.00(0.0; 25.0) (0.52; 4.87) | 13.5 (21.0) 4.5(0.0; 100.0) (5.6; 21.3) | 0.0050 |
| 3 wk | 0.375 (1.04) 0.0(0.0; 5.0) (0.00; 0.75) | 8.23 (17.25) 0.0(0.0; 70.0) (1.79; 14.68) | 0.013 |
| 12 wk | 0.14 (0.52) 0.0(0.0; 2.0) (0; 0.33) | 5.79 (13.75) 0.00(0.00; 60.00) (0.56; 11.02) | 0.0076 |
| No loss of sensibility (0 mm) | |||
| 9 d | 24 (72.7%) | 13 (43.3%) | |
| 3 wk | 27 (84.4%) | 18 (60.0%) | |
| 12 wk | 27 (93.1%) | 19 (65.5%) | |
| Soft tissue overgrowth | 0 (0.0%) | 0 (0.0%) | 1.00 |
| Mean skin level at 12 wk | 5.02 (1.42) (4.48; 5.56) | 5.08 (1.04) (4.68; 5.47) | 0.64 |
| Wound healing | |||
| 9 d | 7 (21.2%) | 5 (16.7%) | 0.89 |
| 3 wk | 22 (68.8%) | 20 (71.4%) | 0.82 |
| 12 wk | 29 (100.0%) | 29 (100.0%) | 1.00 |
| Pain scoringsa | |||
| Pain around implant | |||
| 9 d | 1.39 (1.87) 0.00(0.00;6.00) (0.73; 2.06) | 1.97 (2.61) 1.00(0.00:8.00) (0.99; 2.94) | 0.50 |
| 3 wk | 0.938 (1.22) 0.0(0.00;4.00) (0.50; 1.38) | 1.0 (1.61) 0.0(0.00;6.00) (0.04; 1.60) | 0.67 |
| 12 wk | 1.38 (2.23) 0.00(0.00;8.00) (0.53; 2.23) | 1.17 (2.04) 0.00(0.00;7.00) (0.40; 1.95) | 0.54 |
| Radiating pain | |||
| 9 d | 0.61 (1.66) 0.0(0.00;7.00) (0.02; 1.19) | 0.5 (1.57) 0.0(0.00;8.00) (0.0; 1.09) | 0.95 |
| 3 wk | 0.56 (1.39) 0.0(0.00;5.00) (0.06; 1.06) | 0.43 (1.36) 0.0(0.00;5.00) (0.0; 0.94) | 0.39 |
| 12 wk | 0.76 (1.86) 0.0(0.00;6.00) (0.05; 1.47) | 0.76 (1.8) 0.0(0.00;7.00) (0.04; 1.48) | 0.77 |
| Presence of headache | |||
| 9 d | 0.42 (1.39) 0.0(0.00;7.00) (0.0; 0.92) | 1.30 (2.39) 0.00(0.00;8.00) (0.41; 2.19) | 0.077 |
| 3 wk | 0.375 (1.476) 0.0(0.00;6.00) (0.0; 0.91) | 0.30 (1.32) 0.0(0.00;7.00) (0.0; 0.79) | 0.96 |
| 12 wk | 0.79 (2.1) 0.0(0.00;8.00) (0.00; 1.59) | 0.24 (0.83) 0.0(0.00;4.00) (0.08; 0.56) | 0.59 |
| Skin sagging at 12 wk | |||
| Quadrant 1 | 4 (13.8%) | 4 (14.3%) | 1.00 |
| Quadrant 2 | 7 (24.1%) | 19 (67.9%) | 0.0020 |
| Quadrant 3 | 1 (3.4%) | 1 (3.6%) | 1.00 |
| Quadrant 4 | 1 (3.4%) | 2 (7.1%) | 0.97 |
| Any quadrant | 8 (27.6%) | 20 (71.4%) | 0.0020 |
| Cosmetic resultsb | |||
| Observer scorings | |||
| Natural skin position | 2.72 (1.10) (2.31; 3.14) | 3.48 (1.38) (2.96; 4.01) | 0.025 |
| Extent of baldness | 2.24 (0.79) (1.94; 2.54) | 3.62 (1.35) (3.11; 4.13) | <0.0001 |
| Scarring | 2.41 (0.95) (2.05; 2.77) | 4.48 (1.79) (3.80; 5.16) | <0.0001 |
| Skin colour | 3.17 (1.23) (2.71; 3.64) | 3.86 (1.27) (3.38; 4.35) | 0.020 |
| Indentation | 2.34 (1.01) (1.96; 2.73) | 4.00 (1.63) (3.38; 4.62 | <0.0001 |
| Overall cosmetic score | 8.45 (0.74) (8.17; 8.73) | 7.17 (1.20) (6.72; 7.63) | <0.0001 |
| Subject scorings | |||
| Without processor (BAHS) | 8.42 (1.47) (7.83; 9.02) | 8.61 (1.29) (8.11; 9.11) | 0.75 |
| With processor attached | 7.41 (2.58) (6.39; 8.43) | 7.89 (1.83) (7.18; 8.60) | 0.73 |
| Tertiary Outcome | MIPS (n = 29) | Linear Incision (n = 29) | |
| Pocket size (normal position) (mm) | 0.207 (0.292) (0.096; 0.318) | 0.172 (0.251) (0.077; 0.268) | NP |
| Pocket size (maximum) (mm) | 0.672 (0.418) (0.513; 0.831) | 0.698 (0.440) (0.531; 0.866) | NP |
| Sound processor usage (h per wk) | 70.5 (37.2) (56.3; 84.6) | 90.3 (25.5) (80.3; 100.4) | NP |
Categorical variables: n (%). Continuous variables: mean (SD) (95% CI).
aMean (SD), median (min; max) (95% CI of the mean).
bCosmetic rating: observer outcomes (not including overall cosmetic score): 1–10. 1 being no difference with the healthy contralateral site, with 10 being the most negative difference with the healthy situation. Overall cosmetic and subject scorings: 1–10: 10 being the best cosmetic result and 1 being the most negative cosmetic result.
NP indicates not planned; MIPS, minimally invasive ponto surgery; BAHS, bone-anchored hearing systems.