Table 4 Outcome measure: Pain of operation / Post-operative pain (n = 25)

Conservative treatment (e.g., braces and gutter treatment) v’s Chemical matrixectomy (n = 2 studies)

 AlGhamdi (2014) [19]

A: Lateral nail avulsion with phenol (n = 30)

Time that post-operative pain lasted. Timepoint unclear

29.48 h

p = 0.057

B: Nail tube splinting (n = 23)

21.91 h

 Ceren (2013) [50]

A: Partial nail extraction with phenol matrixectomy (n = 63 toenails)

Pre- and post-operative pain at 2 days, 1- and 6-months post procedure

Not reported

Postoperative pain scores were lower than preoperative scores in both groups (p < .001)^a

B: Partial nail elevation and flexible tube (57 toenails)

Not reported

Conservative treatment (e.g., braces and gutter treatment) v’s surgical matrixectomy (n = 1 study)

 Kruijff (2008) [45]

A: Partial nail extraction with partial matrix excision (n = 58)

4, 12 and 26 weeks

(scale of 1–10) post-operative pain

4 weeks: 5.74*

12 weeks: 7.65*

26 weeks: 5.64*

4 weeks: p = 0.010

12 weeks: p = 0.060

26 weeks: p < 0.010

B: Orthonyxia (n = 51)

4 weeks: 8.11*

12 weeks: 9.74*

26 weeks: 9.62*

Chemical matrixectomy v’s Surgical matrixectomy (n = 9 studies)

 Morkane (1984) [48]

A: Segmental or angular phenolisation (n = 54)

1 week (10 cm linear analogue scale)

20.72 mm (± 25.56)

No significant difference between groups

B: Wedge excision (n = 53)

24.58 mm (± 28.96)

 Leahy (1990) [40]

A: Chemical ablation (phenol) (n = 32)

‘Patient acceptability’ which was partly defined as an absence of severe post-operative pain requiring additional analgesia. 16-month follow-up

One participant found the procedure unacceptably painful

No further analysis is given

B: Surgical ablation (n = 34)

One participant found the procedure unacceptably painful

 Van der Ham (1990) [28]

A: Wedge excision (n = 124)

Number of days analgesic was used

68 (54%) participants for a mean number of 1.1 days

p < 0.001

B: Segmental phenol cauterisation (n = 125)

25 (20%) participants for 0.4 days

 Issa (1988) [51]

A: Wedge resection (WR) and segmental phenolisation (SP) combination treatment (n = 62)

Duration of pain and intensity (No pain, mild, moderate and severe) over 24 h

Duration: 9.4 h [SD 13.5]

Intensity: No pain n = 19; mild n = 20; moderate n = 19, severe n = 4

Duration: No significant difference was identified between the SP and WR/SP but both groups were significantly shorter than the WR (both p < 0.001)

Intensity: No significant difference between the SP and WR/SP groups. Both groups were significantly less than the WR group (SP = p < 0.001 and WR/SP = p < 0.005)

B: Wedge resection (n = 55)

Duration: 30 h [SD 37.6]

Intensity: No pain n = 5; mild n = 8; moderate n = 30, severe n = 12

C: Segmental phenolisation (n = 53)

Duration: 6.7 h [SD 13.0]

Intensity: No pain n = 17; mild n = 18; moderate n = 17, severe n = 1

 Gerritsma-Bleeker (2002) [46]

A: Partial nail extraction with phenolisation (n = 31)

Preoperative, 2 days, 8 days, 1 month, 3 months, 12 months; day- and night-time pain (VAS)

Daytime

Pre: 5.9 (2.4)

2 days: 3.8 (2.7)

8 days: 2.3 (1.8)

1 month: 1.6 (1.6)

3 months: 1.2 (0.7)

12 months: 1.7 (1.8)

Night-time

Pre: 3.4 (3.0)

2 days: 3.0 (2.7)

8 days: 1.9 (2.2)

1 month: 1.3 (0.9)

3 months: 1.0 (0.2)

12 months: 1.0 (0.0)

Daytime

Pre: p = 0.980

2 days: p = 0.099

8 days: p = 0.410

1 month: p = 0.160

3 months: p = 0.190

12 months: p = 0.10

Night-time

Pre: p = 0.210

2 days: p = 0.580

8 days: p = 0.240

1 month: p = 0.130

3 months: p = 0.320

12 months: p = 0.360

B: Partial nail extraction with matrix excision (n = 34)

Daytime

Pre: 5.9 (2.4)

2 days: 3.8 (2.5)

8 days: 1.9 (1.4)

1 month: 1.2 (0.6)

3 months: 1.8 (2.0)

12 months: 1.2 (0.6)

Night-time

Pre: 4.4 (3.1)

2 days: 2.6 (2.2)

8 days: 1.4 (1.3)

1 month: 1.0 (0.2)

3 months: 1.2 (0.8)

12 months: 1.0 (0.2)

 Shaath (2005) [49]

A: Zadik’s procedure (n = 38)

1 week (VAS 0–10, 10; being agony)

Not reported

p = 0.200

B: Chemical ablation with Sodium Hydroxide (n = 45)

Not reported

 Korkmaz (2013) [38]

A: Partial matrix excision (n = 17)

Post-operative pain intensity (mild, moderate, severe). Timepoint unclear

Pain intensity: 3 (17.6%) reported moderate pain. None had severe pain

P =  > 0.05

B: Segmental phenolisation (n = 22)

Pain intensity: 2 (9%) reported moderate pain. None had severe pain

 Akkus (2018) [18]

A: Chemical matrixectomy with NaOH (n = 30)

3 days, 7 days, 1 month after operation (no pain, mild, moderate or severe)

Not reported

Day 3: p = 0.001

No significant difference in the pain severity between groups

for post-operative Day 7 and Month 1

B: Wedge resection (n = 30

Not reported

 Muriel-Sánchez (2020) [24]

A: Chemical matrixectomy with phenol (n = 10)

Post surgical pain at 24, 48 and 72 h (VAS scale 0–10)

24 h: 1.9 ± 1.0 [95% CI 1.31 to 2.49]

48 h:1.2 ± 1.4 [95% CI 0.74 to 1.66]

72 h: 0.8 ± 1.2 [95% CI 0.41 to 1.19]

24 h: p = 0.410

48 h: p = 0.280

72 h: p = 0.330

B: “Aesthetic reconstruction” (describes partial nail ablation with wedge excision of matrix) (n = 24)

24 h: 2.6 ± 2.5 [95% CI 2.04 to 3.16]

48 h: 1.9 ± 2.2 [95% CI 1.41 to 2.39

72 h: 1 ± 1.3 [95% CI 0.71 to 1.29]

Chemical v’s Other chemical (n = 3 studies)

 Gem (1990) Study 1[21]

A: Chemical ablation with 3-min application of 80% phenol (n = 109)

‘days of becoming pain free’

The average time to become pain-free was

3.6 days, with no statistical difference between the groups studied

No statistical analysis information provided

B: Chemical ablation with 2-min application of 10% sodium hydroxide (n = 110)

The average time to become pain-free was

3.6 days, with no statistical difference between the groups studied

 Andre (2018) [33]

A: Nail avulsion and phenol (n = 46 toenails)

34 days post-surgery (VAS 0–10)

Overall mean score was below 2/10 for both groups

Pain was initially higher in the trichloroacetic acid group but this decreased faster than in the phenol group. No further information or statistical analysis provided

B: Nails avulsion and trichloroacetic acid (n = 50 toenails)

Overall mean score was below 2/10 for both groups

 Ahsan (2019) [42]

A: Chemical matrixectomy with phenol (n = 50)

No pain, mild, moderate, or severe. Timepoint unclear

Severe pain n = 2

Moderate pain n = 4

Mild pain n = 23

p = 0.472^a

B: Chemical matrixectomy with trichloroacetic acid (n = 50)

Severe pain n = 0

Moderate pain n = 4

Mild pain n = 19

Chemical timings (n = 3 studies)

 Gem (1990) Study 2[21]

A: Chemical ablation with 2-min application of 10% sodium hydroxide (n = 110)

‘days of becoming pain free’

The average time to become pain-free was

3.6 days, with no statistical difference between the groups studied

No statistical analysis information provided

B: Chemical ablation with 1-min application of 10% sodium hydroxide (n = 93)

The average time to become pain-free was

3.6 days, with no statistical difference between the groups studied

 Tatlican (2009) [27]

A: Partial nail avulsion with 1 min phenol cauterisation (n = 37)

2, 10, 16, 24 and 30 days (‘Present’ or ‘absent’)

2 days: 19 (51.4%)

Mean days present: 1.4 (± 1.4) days

2 days: p = 0.846

Mean Days: p = 0.527

B: Partial nail avulsion with 2-min phenol cauterisation (n = 36)

2 days: 16 (44.4%)

Mean days present: 1.1 (± 1.2) days

C: Partial nail avulsion with 3-min phenol cauterisation (n = 37)

2 days: 19 (51.4%)

Mean days present: 1.3 (± 1.3) days

 Muriel-Sánchez (2021) [25]

A: Partial nail avulsion with 30 s application of phenol (n = 27 halluces [54 nail folds])

24, 48, 72 h post-surgery (VAS)

24 h: 1.7 [SD 0.5] (95% CI 1.5–1.9; Median 2, IQR 1)

48 h: 1.9 [SD 1.8] (95% CI 1.19–2.61; Median 1, IQR 2)

72 h: 1.2 [SD 1.3] (95% CI 0.69–1.71; Median 1, IQR 2)

24 h: p = 0.650

48 h: p = 0.720

72 h: p = 0.790

B: Partial nail avulsion with 60 s application of phenol (n = 27 halluces [54 nail folds])

24 h: 1.6 [SD 0.6] (95% CI 1.6–1.84; Median 2, IQR 1)

48 h: 1.1 [SD 1.3] (95% CI 0.59–1.61; Median 1, IQR 2)

72 h: 0.7 [SD 1.1] (95% CI 0.26–1.14; Median 0, IQR 1)

Chemical matrixectomy v’s Surgical + chemical matrixectomy (n = 2 studies)

 Issa (1988) [51]

A: Wedge resection and segmental phenolisation combination treatment (n = 62)

Duration of pain and intensity (No pain, mild, moderate and severe) over 24 h

Duration: 9.4 h [SD 13.5]

Intensity: No pain n = 19; mild n = 20; moderate n = 19, severe n = 4

Duration: No significant difference was identified between the SP and WR/SP but both groups were significantly shorter than the WR (both p < 0.001)

Intensity: No significant difference between the SP and WR/SP groups. Both groups were significantly less than the WR group (SP = p < 0.001 and WR/SP = p < 0.005)

B: Wedge resection (n = 55)

Duration: 30 h [SD 37.6]

Intensity: No pain n = 5; mild n = 8; moderate n = 30, severe n = 12

C: Segmental phenolisation (n = 53)

Duration: 6.7 h [SD 13.0]

Intensity: No pain n = 17; mild n = 18; moderate n = 17, severe n = 1

 Alvarez-Jimenez (2011) [31]

A: Phenol and curettage (n = 73 nail folds)

Post-operative pain 2 days after procedure (10 cm VAS scale, 0 no pain,10 maximum pain)

3.95 ± 2.25

p = 0.028

B: Phenol (n = 79 nail folds)

3.06 ± 2.21

Chemical matrixectomy v’s ‘Other’ (e.g., laser and electrocautery) (n = 1 study)

 Hamid (2021) [36]

A: Partial nail avulsion and matrixectomy with phenol (n = 50)

Post-operative pain (mild, moderate or severe). Timepoint unclear

Mild pain (n = 17/50)

Moderate pain (n = 6/50)

Severe pain (n = 1/50)

Mild: p = 0.660

Moderate: p = 1.00

Severe: p = 1.00

B: Partial nail avulsion and matrixectomy with electrocautery (n = 50)

Mild pain (n = 14/50)

Moderate pain (n = 6/50)

Severe pain (n = 2/50)

Surgical matrixectomy v’s Surgical + chemical matrixectomy (n = 1 study)

 Issa (1988) [51]

A: Wedge resection and segmental phenolisation combination treatment (n = 62)

Duration of pain and intensity (No pain, mild, moderate and severe) over 24 h

Duration: 9.4 h [SD 13.5]

Intensity: No pain n = 19; mild n = 20; moderate n = 19, severe n = 4

Duration: No significant difference was identified between the SP and WR/SP but both groups were significantly shorter than the WR (both p < 0.001)

Intensity: No significant difference between the SP and WR/SP groups. Both groups were significantly less than the WR group (SP = p < 0.001 and WR/SP = p < 0.005)

B: Wedge resection (n = 55)

Duration: 30 h [SD 37.6]

Intensity: No pain n = 5; mild n = 8; moderate n = 30, severe n = 12

C: Segmental phenolisation (n = 53)

Duration: 6.7 h [SD 13.0]

Intensity: No pain n = 17; mild n = 18; moderate n = 17, severe n = 1

Surgical matrixectomy v’s ‘Other’ (e.g., laser and electrocautery) (n = 2 studies)

 Kavoussi (2020) [22]

A: Partial Nail Matrixectomy using CO₂ laser (n = 62)

Duration of pain. Timepoint unclear. Participants were followed over 24 months

3.20 days [± 1.734]

p = 0.620

B: Lateral Nail Fold Excision (LNFE) (n = 65)

3.66 days [± 2.111]

 Awad (2020) [20]

A: Partial nail matrixectomy with electrocautery (n = 100)

Day 3 and 7 (Likert Scale, none, mild moderate or severe pain)

Three days: 32% no pain, 15.5% mild, 2.5% moderate, 0% severe

Seven days: 44.5% no pain, 3% mild, 2.5% moderate, 0% severe

p = 0.018 + 

B: Partial nail matrixectomy (n = 100)

Three days: 39.5% no pain, 9% mild, 1.5% moderate, 0% severe

Seven days: 46% no pain, 2.5% mild, 1.5% moderate, 0% severe

Surgical v’s Surgical (n = 1 study)

 Habeeb (2020) [47]

A: Central toenail resection (n = 50)

2, 3, 4 days post-operative pain (absent or present)

Day 2: present in 12 participants

Day 3: present in 2 participants

Day 4: present in 0 participants

Day 2: p < 0.001

Day 3: p = 0.004

Day 4: p = 0.001

B: Wedge toenail resection (n = 50)

Day 2: present in 35 participants

Day 3: present in 12 participants

Day 4: present in 10 participants

Chemical matrixectomy v’s Avulsion only (n = 1 study)

 Khan (2014) [37]

A: Partial Nail Avulsion + Phenol (n = 50)

Day 3 and 7 post-operative pain (none, mild, moderate and severe)

Day 3: 2% no pain, 31% mild, 12% moderate, 5% severe

Day 7: 40% no pain, 6% mild, 3% moderate, 1% severe

p = 0.018^a

B: Partial Nail Avulsion alone (n = 50)

Day 3: 0% no pain, 18% mild, 22% moderate, 10% severe

Day 7: 35% no pain, 10% mild, 3% moderate, 2% severe

Anaesthetics (with and without epinephrine) (n = 2 studies)

 Altinyazar (2010) [30]

A: Plain lidocaine (n = 22)

1-day post-operative pain (mild, moderate, severe)

Mild pain n = 10

Moderate pain n = 2

Severe pain n = 0

There was no statistically significant difference in

postoperative pain

B: Lidocaine with epinephrine (n = 22)

Mild pain n = 9

Moderate pain n = 2

Severe pain n = 0

 Cordoba-Fernandez (2015) [43]

A: Segmental phenolisation matrixectomy with anaesthetic digital block with epinephrine (n = 34 toes)

3 days post-surgery (Scale 1–10)

Day 1: 4 (2.74)

Day 2: 4.07 (2.26)

Day 3: 3.24 (1.73)

p =  > 0.05^a

B: Segmental phenolisation matrixectomy with anaesthetic digital block without epinephrine (36 toes)

Day 1: 3.92 (1.85)

Day 2: 4.64 (1.98)

Day 3: 2.94 (1.98)