Table 1 Characteristics of included studies

Ahsan (2019) [27]

RCT (Pakistan)

3 months

100 participants; Mean age 26.31 + 8.74; 45/46 M/F; Severity not reported

A: Chemical matrixectomy with phenol (n = 50)

1. Healing time at 48 h, week 1, 4 and 12 up to 3 months.

2. Wound infection and discharge

3. Pain (no pain, mild, moderate, severe)

4. Recurrence up to 3 months

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

Akkus (2018) [28]

RCT (Turkey)

12 months

60 participants (75 procedures); Mean age 30 – 31.7; 27/23 M/F; Stage I (n = 32), Stage II (n = 19), Stage III (n = 24)

A: Chemical matrixectomy with NaOH (n = 30)

1. Recurrences at 12 months

2. Healing time assessed at day 3, Week 1, Month 1, 6, and 12

3. Pain (pain severity- mild, moderate or severe)

4. Operation time

5. Post-operative drainage

6. QOL (Dermatologic Life Quality Index)

B: Wedge resection (n = 30)

AlGhamdi (2014) [29]

RCT (Saudi Arabia)

6 months

53 participants; Mean age 47.7 + 1.3 (range 10–60 years); 46/7 M/F; Stage II and III

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

1. Symptomatic regrowth 1, 3 and 6 months

2. Healing time 1, 3 and 6 months

3. Significant complications including infection

4. Pain at baseline, 1, 3 and 6 months

5. Participant satisfaction

6. Drainage

7. Shoe-wear discomfort

8. Overall success rate

B: Nail tube splinting (n = 23)

Altinyazar (2010) [30]

RCT (Turkey)

18 months

44 participants; Mean 28.5–32.8; 21/23 M/F; All stage III

A: Plain lidocaine (n = 22)

1. Recurrence at 18 months

2. Healing time

3. Pain

4. Drainage

B: Lidocaine with epinephrine (n = 22)

Alvarez-Jimenez (2011) [31]

RCT; Double- Blinded (Spain)

12 months

51 participants (152 procedures); Mean age 34.05 + 19.23; 18/33 M/F; Stage I or IIa

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

1. Recurrence at 12 months

2. Healing time over 1 months (digital photo)

3. Infection

4. Bleeding over 48 h

5. Pain 2 days post-surgery (VAS)

B: Phenol (n = 79 nail folds)

Anderson (1990) [32]

RCT (UK)

12 months

31 participants; Age range 15–73 years); 19/11 M/F; Severity not reported

A: Nail bed excision (n = 17)

1. Recurrence at 12 months

2. Post operative infection at 2 weeks

3. Participant satisfaction at 2 weeks and 12 months

4. Previous operations and relation to recurrence

B: Combination of nail bed phenolisation and excision (n = 14)

Andre (2018) [33]

RCT; Double- Blinded (France)

4 months

84 participants (96 toenails); Age range 14–88 years; 41/40 M/F; Severity not reported

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

1. Recurrence at 4 months

2. Inflammation at day 2, week 2, 4 and month 4

3. Pain at 34 days post-surgery (VAS)

4. Presence of oozing

5. Postoperative morbidity

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

Awad (2020) [34]

RCT (Saudi Arabia)

6 months

200 participants; Mean age 26.45 (range 16–52 years); 136/64 M/F; Stage I (n = 66), Stage II (n = 38), Stage III (n = 96)

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

1. Recurrence at 1 and 6 months

2. Healing time assessed at 3 and 7 days, 1 and 6 months

3. Infection assessed at 3 and 7 days

4. Pain assessed at day 3 and 7 (VAS)

5. Participant satisfaction at 1 and 6 months

B: Partial nail matrixectomy (n = 100)

Bos (2007) [35]

RCT (Netherlands)

12 months

123 participants; Age range 9–73; 72/45 M/F; Severity not reported

A: Partial avulsion with excision of the matrix (n = 38)

1. Recurrence at 1, 6 and 12 months

2. Infection at 2 days, 1 week and 1 month

B: Partial avulsion of the matrix and application of antibiotic (n = 22)

C: Partial avulsion with application of phenol (n = 37)

D: Partial avulsion with application of phenol and antibiotic (n = 26)

Ceren (2013) [36]

RCT (Turkey)

6 months

120 toenails; Age range (11–65 years); 59/48 M/F; Stage I (n = 31), Stage II (n = 17), Stage III (n = 72)

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

1. Recurrence at 6 months

2. Haemorrhage or discharge at 6 months

3. Pain at 6 months

4. Cosmetic satisfaction at 6 months

5. Time to recovery

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

Cordoba-Fernandez (2015) [37]

RCT (Spain)

12 months

44 participants (10 toes); Mean age 26.28 + 15.82 (range 10–64 years); 21/23 M/F; Severity not reported

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

1. Recurrence

2. Bleeding

3. Pain at 1-, 2- and 3-days post-op (VAS)

4. Duration of anaesthetic effect

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

Gem (1990) Study 1[22]

Prospective RCT (UK)

18 months

219 participants; age, gender and severity not reported

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

1. Recurrence at 18 months

2. Time to become pain free

3. Relief of symptoms

4. Healing time

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

Gem (1990) Study 2 [23]

Prospective RCT (UK)

18 months

203 participants; age, gender and severity not reported

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

1. Recurrence at 18 months

2. Time to become pain free

3. Relief of symptoms

4. Healing time

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

Gerritsma-Bleeker (2002) [38]

RCT (Netherlands)

12 months

60 participants (63 procedures); Mean age 22.7- 24.4; 30/33 M/F; Severity not reported

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

1. Relief of symptoms at 1, 3 and 12 months (VAS)

2. Recurrence at 1, 3 and 12 months

3. Pain at 2 days, 8 days, 1 month, 3 months, 12 months (VAS)

4. Participant satisfaction with scar and cosmetic result at 1, 3 and 12 months (VAS)

5. Erythema & purulent exudates

6. Morbidity

7. Time to complete recovery

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

Greig (1991) [39]

RCT (Scotland)

12 months

163 participants (204 procedures); Age range 12–77 years; 113/50 M/F; Severity not reported

A: Total avulsion (n = 81 nail edges)

1. Recurrences at 12 months

2. Postoperative infection after 2 weeks

3. Participant satisfaction at 12 months

B: Nail edge excision (n = 56 nail edges)

C: Nail edge excision and phenolisation (n = 67 nail edges)

Habeeb (2020) [40]

RCT (Egypt)

6 months

100 participants; Age range 10–35 years; 78/22 M/F; Severity not reported

A: Central toenail resection (n = 50)

1. Relief of symptoms at 4 and 8 weeks

2. Recurrences at 6 months

3. Pain at 1,2,3 and 4 days post-op

4. Duration of technique

B: Wedge toenail resection (n = 50)

Hamid (2021) [25]

RCT (Pakistan)

6 months

100 participants; Mean age 19.7–20.2; gender and severity note reported

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

1. Recurrence at 3 and 6 months

2. Serous and Purulent discharge at 7th and 14th days and at week 4 and 6

3. Pain

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

Issa (1998) [41]

RCT (Ireland)

6 months

140 participants (170 procedures); Mean age 21 (range 9–54 years); 65/22 M/F; Severity not reported

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

1. Recurrence at 6 months

2. Pain duration at 1–6 h, 6–12 h, 12–24 h, > 24 h post-op

3. Pain intensity using the linear pain analogue scale

B: Wedge resection (n = 55)

C: Segmental phenolisation (n = 53)

Kavoussi (2020) [42]

RCT (Iran)

24 months

127 participants; Mean age 28.2–28.9; 68/59 M/F; Stage I (n = 7), Stage IIa (n = 40), Stage IIb (n = 51), Stage III (n = 21), Stage IV (n = 8)

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

1. Spicule formation

2. Healing time

3. Infection

4. Pain

5. Cosmetic outcome

6. Time to return to daily activity

7. Time to return to work

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

Khan (2014) [43]

RCT (Pakinstan)

6 months

100 participants; Mean age 18 (range 14–45 years); M:F ratio = 2.3:1; Severity not reported

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

1. Recurrence or spike formation at 1 and 6 months

2. Infection at 3^rd and 7^th day post-op

3. Pain at 3^rd and 7^th day post-op (VAS)

4. Mortality

B: Partial Nail Avulsion alone (n = 50)

Kim (2015) [44]

RCT (Korea)

6 months

61 participants; Mean age 20.0 – 20.3; All male; Grade 2 or 3

A: Curettage (n = 32)

1. Recurrences at 6 months

2. Infection at 3–5 days post-op

B: Electrocautery (n = 29)

Korkmaz (2013) [45]

RCT (Turkey)

Mean 3.2 ± 1.2 years

39 participants; Mean age 16.1–17.0; 28/11 M/F; Stage 2 (n = 13) or 3 (n = 26)

A: Partial matrix excision (n = 17)

1. Recurrence

2. Infection

3. Pain (Duration of analgesic usage)

4. Return to work time

Mean 2.1 ± 0.9 years

B: Segmental phenolisation (n = 22)

Kruijff (2008) [46]

RCT (Netherlands)

12 months

105 participants (109 nails procedures); Mean age 25.3 + 15.2; 73/36 M/F; Severity not reported

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

1. Recurrence at 12 months

2. Redness, exudate and post-operative bleeding at 1 week

3. Pain at 4, 12 and 26 weeks (VAS)

4. Participant satisfaction at 4 and 26 weeks (VAS)

5. Time to complete recovery

6. Relief of symptoms (VAS)

B: Orthonyxia (n = 51)

Leahy (1990) [47]

RCT (Ireland)

30 months

66 participants; Mean age 24 years; 48% females; Severity not reported

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

1. Spicules or spikes regrowth at 3 months and between 16 and 30 months

2. Infection at 1 week, 3 months, and between 16 and 30 months

3. Haemorrhage at 1 week, 3 months, and between 16 and 30 months

4. Cosmetic outcome between 16 and 30 months

5. Postoperative pain (absence of pain relief) at 1 week, 3 months and between 16 and 30 months

6. Participant satisfaction at 16 and 30 months

B: Surgical ablation (n = 34)

Misiak (2014) [48]

RCT (Poland)

3 months

60 participants; Mean age 41.4 + 9.95 (range 26–64 years); 32/28 M/F; Grade 3 and 4

A: Partial nail extraction + phenolisation (n = 30)

1. Recurrence at 1, 2 and 3 months

2. Healing time at 7 days, 14 days, 1, 2 and 3 months

B: Partial nail extraction + electrocautery (n = 30)

Morkane (1984) [49]

RCT (New Zealand)

14 months

103 participants (107 procedures); Mean age 24.6 – 28.5; M/F ratio 3.5:1; Severity not reported

A: Segmental or angular phenolisation (n = 54)

1. Regrowth at mean follow up time of 14 months

2. Pain measured 1 week post-operatively (linear analogue scale)

B: Wedge excision (n = 53)

Muriel-Sánchez (2020) [50]

RCT (Spain)

6 months

34 participants (112 procedures); Mean age 34 + 18.3; 12/22 M/F; Stage I or IIa

A: Chemical matrixectomy with phenol (n = 10)

1. Recurrence at 6 months

2. Healing time

3. Post-surgical bleeding at first dressing

4. Infection

5. Pain at 24, 48, 72 h (VAS)

6. Post-surgical inflammation

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

Muriel-Sánchez (2021) [51]

RCT (Spain)

6 months

27 participants (108 procedures); Mean age 36 + 10.7 years; 8/19 M/F; Stages I or IIa

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

1. Recurrence at a minimum of 6 months

2. Healing time

3. Inflammation, bleeding & infection at 72 h then twice weekly until healed

4. Pain at 1, 2 and 3 days post-op (VAS)

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

Peyvandi (2011) [52]

Prospective RCT (Iran)

6 months

100 participants; Mean age 27.8 (range 12–47 years); 54/46 M/F; Severity not reported

A: Winograd method (n = 50)

1. Recurrence at 1 week, 1 and 6 months

2. Infection at 1 week, 1 and 6 months

3. Postoperative workday loss

4. Surgery duration

5. Participant satisfaction

B: Sleeve (gutter) method (n = 50)

Reyzelman (2000) [21]

RCT (US)

Until healed

154 participants; Mean age 20.7 + 8.6 (range 10–60 years); 91/63 M/F; Severity not reported

A: 1 week course of oral antibiotics and simultaneous phenol matrixectomy (n = 53)

1. Healing time assessed at 3–4 days then weekly until healing occurred

2. Infection assessed at 3–4 days then weekly until healing occurred

B: 1 week course of oral antibiotics and phenol matrixectomy 1 week later (n = 51)

C: Phenol matrixectomy without antibiotic therapy (n = 50)

Shaath (2005) [53]

RCT (UK)

12 months

83 participants; Mean age 37.2 – 39.4 years; 53/30 M/F; Severity not reported

A: Zadik’s procedure (n = 38)

1. Symptomatic regrowth

2. Pain at 3 & 6 weeks (VAS)

3. Return to shoe wear

4. Return to normal activity

5. Number of dressings

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

Tatlican (2009) [20]

RCT (Turkey)

24 months

110 participants (148 procedures); Mean age 31.6–32.7 years. 54/56 M/F;

Grade 2 (n = 65) or 3 (n = 83) ingrowing nail

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

1. Recurrence at 6-month intervals for 24 months

2. Healing time. Examined on alternate days until healing achieved

3. Pain at 2^nd, 10^th, 16^th, 24^th & 30^th days of follow up

4. Drainage and tissue damage at 2^nd, 10^th, 16^th, 24^th & 30^th days of follow up

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

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

Uygur (2016) [54]

Prospective RCT (Turkey)

6 months

128 participants; Mean age 22.8 (range 12–48 years); 83/41 M/F; Heifetz stage I (n = 28, 23%), Stage I (n = 73, 58%), Stage III (n = 23, 18%)

A: Winograd procedure and new suturing technique (n = 64)

1. Recurrence at 2 weeks, 1 and 6 months

2. Satisfaction at suture removal, 1 and 6 months

3. Time elapsed before shoes could be worn at 2 weeks, 1 and 6 months

4. Return to work/school

B: Winograd procedure and traditional suturing technique (n = 64)

Van der Ham (1990) [55]

RCT (Netherlands)

14 months

249 participants; Age range 3–97 years; 158/ 91 M/F; Severity not reported

A: Wedge excision (n = 124)

1. Analgesic required after 7 days and weekly until healed for 14 months

2. Sick leave

3. Recurrence for 14 months

4. Re-operation

5. Nail Spikes

6. Healing time

7. Time required off work

B: Segmental phenol cauterisation (n = 125)

Varma (1983) [26]

RCT (UK)

6 months

67 participants; Age, gender and severity not reported

A: Surgical wedge excision (n = 35)

1. Symptomatic recurrence at 3 and 6 months

2. Healing time at 1 week, 1 and 3 months

B: Phenol wedge cauterisation (n = 28)

Wallace (1979) [24]

Prospective RCT (UK)

15 months

68 participants; Age range 10 to 73 years; gender and severity not reported

A: Gutter treatment (n = 32)

1. Number of successes/Number of failures

2. Number having no further operation/ Number undergoing reoperation

3. Pain after 1 day

B: Wedge resection (n = 36)