• Article highlight
  • Article tables
  • Article images

Article History

Received : 04-04-2024

Accepted : 02-05-2024



Article Metrics




Downlaod Files

   


Article Access statistics

Viewed: 251

PDF Downloaded: 115


Get Permission Coll and Beech: Scarf vs minimally invasive 5th metatarsal osteotomy for the reduction of tailors bunions: A systematic review and meta-analysis


Introduction

Growing interest in minimally invasive surgery (MIS) has resulted with an explosion of percutaneous reconstructive techniques over the last decade. Early advocates of MIS report comparable outcomes to open surgery with reduced complications, however this remains a subject of debate with traditionalists defensibly refuting these claims, touting high reporting and selection bias.1, 2, 3 The surgical management of metatarsus quintus valgus is no exception with conflicting opinions regarding the most effective procedure and technical execution.

Historically bunionettes were considered an adaptation of the 5th metatarsal head within the tailoring trade, however modern surgeons acknowledge the deformity as a complex pathology with multifactorial structural and mechanical drivers (Table 1).4, 5, 6 Early writings explored the concept that mild 5th metatarsal splaying and 5th toe adduction were normal findings within the general population although rather ambiguously argued larger symptomatic deformities should be considered secondary pathology associated with global deformity such as pes plano valgus or hallux valgus.5 Considered an oversimplification, these ideologies have been dispelled however paucity of research, small case series and confounding limits prospective data.

Table 1

Structural and biomechanical factors contributing to tailors’ bunion deformity

Anatomical factors

Biomechanical factors

Congenital dorsiflexed / plantarflexed 5th ray

Prominent 5th lateral metatarsal head

Tight footwear

Hypertrophy of soft tissue overlying lateral aspect of 5th metatarsal head

Lateral bending of the 5th metatarsal

Dumbbell shaped 5th metatarsal

Excessive pronation caused by hypermobility

Supernumeracy ossicles attached to the lateral 4th metatarsal head pushing the 5th metatarsal laterally

Subluxatory position of the 5th metatarsal

Increased 4th and 5th inter-metatarsal angle

Excessive lateral loading

Incomplete insertion or development of the transverse metatarsal ligament

Pes planus

Lateralisation of the 5th metatarsal contributes to a splay forefoot and presents with a typical symptomatologic triad of footwear irritation, plantar lateral callus and chronic adventitious bursal enlargement over the lateral aspect of the 5th metatarsal head.7 Adductovarus 5th toe deformity is a common associated finding which may similarly present with digital pain, rubbing and hyperkeratosis. Radiographic classification (Figure 1) continues to dominate deformity grading and determines the centre of rotation of angulation (CORA) aiding surgical planning.8 Weight bearing (WB) dorso-plantar (DP) and medial oblique (MO) views are arguably the most valuable for classifying bunionette deformities however WB lateral views of the foot and ankle facilitates charting of sagittal plane deformity such as pes planus or cavus which may be of relevance, particularly in revision cases and managing patient expectations.4, 9, 10

Figure 1

a): Radiographic classification of tailors bunions; b): Classification by Fallat and Buckholtz

https://typeset-prod-media-server.s3.amazonaws.com/article_uploads/45e0ac77-6b1a-4c3b-b996-1547add7054e/image/e6a7986a-05bf-45ca-9fe9-505b0358aec4-uimage.png

Surgical reduction is primarily undertaken via 5th metatarsal osteotomy however there remains a lack of consensus regarding the most effective technique. The scarf osteotomy has been described as a versatile procedure with acceptable patient reported outcomes and deformity correction however some have challenged its efficacy reporting increased risk of complications. Increased application of MIS is challenging the status quo, specifically open techniques like the scarf osteotomy citing comparable outcomes with reduced complications owing to reduced dissection, preserved soft tissue envelope, and limited tourniquet use.11 Head-to-head trials are lacking leaving surgeons ambiguous regarding the current evidence and arguably best practice. Systematic review and meta-analysis were performed to investigate two key objectives; Whether the scarf and MIS 5th metatarsal osteotomies have comparable clinical and patient reported outcomes. Secondly, do MIS techniques reduce post-operative complications.

Materials and Methods

In compliance with the preferred reporting items for systematic re- views and meta-analyses (PRISMA), literature was sourced by 2 independent reviewers using electronic multidisciplinary bibliographic databases (Table 2). A PICO (Population, Intervention, Control, Outcome) tool (Table 3) was synthesised by the reviewers to aid research collection, standardize the search, and assist with data extraction. Negotiated medical subheadings (Mesh) and Boolean phrases “And” or “Or” provided a targeted search strategy, with all selected papers cross-referenced to avoid overlooking relevant literature.

Table 2

Bibliographic databases

Bibliographic databases

1.

Allied and Complementary Medicine Database (AMED)

2.

BMJ Best Practice

3.

Cumulative Index to Nursing and Allied Health Literature (CINAHL)

4.

Clinical Key

5.

Cochrane Library

6.

Embase

7.

MEDLINE

8.

Ovid Journals

9.

PubMed

10.

SAGE Journals

11.

Science Direct

12.

Scopus

13.

Springer Journals

14.

Taylor and Francis Online Library

Table 3

PICO for Scarf Osteotomy

Population

Intervention

Outcome

Outcome

Tailors Bunion

Scarf Osteotomy

Not applicable

Results

Bunionette

Scarfette

Outcomes

Metatarsus Quintus Valgus

Reverse Scarf Osteotomy

Post-operative

Fifth metatarsal

Z-cut osteotomy

Complications

Fifth ray

Mid-shaft Osteotomy

Follow up

Valgus fifth metatarsal

Diaphyseal Osteotomy

Patient reported outcomes

Clinical outcomes

Radiographic outcomes

Correction

PICO for MIS

Population

Intervention

Outcome

Outcome

Tailors Bunion

Percutaneous Osteotomy

Not applicable

Results

Bunionette

Percutaneous distal Osteotomy

Outcomes

Metatarsus Quintus Valgus

Minimally invasive Osteotomy

Post-operative

Fifth metatarsal

Complications

Fifth ray

Follow up

Valgus fifth metatarsal

Patient reported outcomes

Clinical outcomes

Radiographic outcomes

Correction

Included papers were required to meet the following criteria: studies utilising the scarf or percutaneous osteotomy for surgical reduction of tailors’ bunions in adults, studies reporting objective pre and post-operative clinical and radiological data, studies providing patient reported outcomes, studies reporting post-operative complications, studies published in English, studies produced between 2000 and 2023. A protracted search period was employed for several reasons although primarily due to paucity of research. Similarly, studies were not discriminated for including patients having concomitant foot surgery. Minimally invasive foot surgery inspired by Boesch’ 1st ray techniques was popularised in 2000, thus arguably birthing its modern concepts and formulated the baseline for this review.12, 13

Excluded papers comprised those where procedures other than 5th metatarsal scarf or percutaneous osteotomies were performed to reduce the tailors’ bunion, studies including paediatric populations, descriptive narratives, failure to disclose complications, studies failing to provide surgeon and patient reported outcomes.

51 texts were initially identified from electronic databases. Application of the PICO tool and inclusion criteria reduced the pool to 11 studies which were accepted for quality assessment: 5 scarf osteotomy and 6 MIS papers inclusive of 115 and 170 surgical episodes respectively.

Figure 2

Prisma flow diagram demonstrating review process

https://typeset-prod-media-server.s3.amazonaws.com/article_uploads/45e0ac77-6b1a-4c3b-b996-1547add7054e/image/cec343c1-92d4-4204-bb3d-942473f1aca6-uimage.png

Figure 2 illustrates a PRISMA flow diagram detailing the review process. Quality assessment of included articles was undertaken using the Joanna Briggs Checklist for Case Series checklist and Coleman Methodology Score due to its high reproducibility and correlation with evidence classification. A Modified Cochrane risk of bias (ROB) further scrutinised included studies.

Statistical analyses of pooled results and Coleman Methodology scoring was performed by each independent reviewer with discrepancies resolved following discussion and the final score decided as a team. Summary recommendations were unanimously agreed between reviewers according to their hierarchical level of evidence (Table 4). Score stratification was agreed between reviewers with 85–100 representing excellent quality, 70–84 good quality, 55–69 fair quality and < 55 demonstrating a poor-quality study.14

Table 4

NICE Hierarchy or evidence and recommendations grading scheme

Level

Type of evidence

Grade

Evidence

I

Evidence obtained from a single randomised controlled trial or a meta‑analysis of randomised controlled trials

A

At least one randomised controlled trial as part of a body of literature of overall good quality and consistency addressing the specific recommendation (evidence level I) without extrapolation

IIa

Evidence obtained from at least one well‑designed controlled study without randomisation

B

Well‑conducted clinical studies but no randomised clinical trials on the topic of recommendation (evidence levels II or III); or extrapolated from level I evidence

IIb

Evidence obtained from at least one other well‑designed quasi‑experimental study

III

Evidence obtained from well‑designed non‑experimental descriptive studies, such as comparative studies, correlation studies and case studies

IV

Evidence obtained from expert committee reports or opinions and/or clinical experiences of respected authorities

C

Expert committee reports or opinions and/or clinical experiences of respected authorities (evidence level IV) or extrapolated from level I or II evidence. This grading indicates that directly applicable clinical studies of good quality are absent or not readily available

Results

Study characteristics

11 studies (Table 5) met the inclusion criteria, 10 of which identified as retrospective case series. 1 study identified as a prospective cohort, however this was considered author error, misrepresentative and for the purposes of this project labelled as case series 1. European and South American dominance was observed across included studies, particularly MIS, with two papers including the same Brazilian faculty, illustrating industry leaders for this technique.15, 16 Two scarf osteotomy studies were conducted in the UK.17, 18 Follow up differed between procedures; 3/5 scarf osteotomy papers demonstrating mid-term review, two of which mid-long term follow up 7 years.18, 19 3/6 MIS studies presented mid-term review, mean follow up 28 months.12, 20, 21 The remaining five studies for both procedures included short term follow up, mean up 12.8 months. Patient demographics were poorly represented except for age and sex. Mean age of study participants was similar in both groups, mean 47 years. One scarf osteotomy paper demonstrated a relatively young group, mean age 26 years, lowering the scarfs average however this was considered sampling bias.22 There was a clear female: male dominance amongst both groups (Scarf 70%; MIS 88%), however 1 paper failed to report differences between sexes limiting pooled scarf numbers.22

Procedural variation

Tourniquet use

40% of included studies reported use of an ankle tourniquet however varied. 2 scarf papers referenced the use of ankle tourniquets as standard practice,18, 22 however MIS studies were more diverse, restricting application of a tourniquet to patients undergoing concomitant 1st ray procedures or complex forefoot reconstruction.12, 20

Osteotomy

Scarf osteotomy was similarly described across all 5 studies with a longitudinal dorso-lateral incision over the 5th metatarsal, layered dissection, lateral tubercle exostectomy, diaphyseal ‘Z’ osteotomy and reduction of deformity owing to medialisation of the plantar fragment. Inter-surgeon variation existed between the angle of the transverse cuts; however, the scarfs geometric interlocking cuts were unanimously maintained. 2 studies performed shortening osteotomies for all patients removing 2-4mm bone blocks from the transverse cuts to decompress the 5th MTPJ and aid mobilisation of the plantar fragment.17, 23 These studies had a similar academic panel and so this procedure modification was assumed to be institution preference. MIS demonstrated considerable variation, most notably osteotomy location and orientation of cuts. All MIS studies similarly reported use of fluoroscopy. 4/6 reported a stab incision to the lateral aspect of the 5th metatarsal, sharp and blunt dissection to expose the lateral cortex of the 5th metatarsal, and percutaneous osteotomy with a 2x12mm Shannon burr. Lui (2014) reported a medial wedge osteotomy using a Isham straight flute burr. Laffenetre et al. (2015) performed a medial closing wedge osteotomy with preservation of the lateral hinge using a long Shannon bur (12x2mm). All studies orientated the burr at 45 degrees in the sagittal plane from dorsal distal lateral to plantar proximal medial to encourage medial transposition, reduce dorsal displacement of the capital fragment and transfer metatarsalgia. One study described a traditional chevron osteotomy with 60–80-degree cuts at the level of the 5th metatarsal head 20. Sub-capital osteotomy was performed in all other studies with a degree of technical variation. 2 studies cited the importance of osteotomy performance at a pre-determined apex of deformity in keeping with Coughlin’s radiographic classification.12, 16 Remaining studies documented a vague reference point within the distal 3rd of the 5th metatarsal.1, 15 Laffenetre et al. (2015) maintained a lateral hinge to aid osteotomy stability, whilst all others performed complete osteotomies. Relevance of hypertrophic lateral tubercles varied across studies with 3 papers performing additional intra-capsular exostectomy where surgeons had concerns regarding residual prominence post-operatively.1, 12, 21

Fixation

Inter-procedure osteosynthesis differed. All scarf osteotomies were fixated with lag screws generating rigid inter-fragmentary compression and absolute stability. Marginal variation in screw fixation was observed in 1 study, with 58% receiving 2 screws, and 42% 1 screw; the rationale for the variation was not defined however it was assumed that this was based on intra-operative findings of construct stability or institution preference.17 No internal fixation was employed for MIS procedures. 1 study performed a medial closing wedge osteotomy, maintaining an intact lateral hinge which was argued to maintain a single point of fixation.12 1 study did not use internal or external fixation.21 Fixation of all other MIS procedures involved external strapping of the 5th digit and or forefoot for intervals ranging from 4-6 weeks.

Post-operative management

Weight bearing protocols varied between authors for both procedures, particularly following scarf osteotomy. 2 scarf studies kept patients non-weight bearing for 3 weeks before allowing protected weight bearing in a post-op shoe for a further 3-6 weeks.19, 23 Immediate partial weight bearing was observed in 3 papers although this ranged from 2-6 weeks.17, 18, 22 2 scarf studies also detailed an initial 4-day inpatient stay, although no rationale for this was provided; otherwise, day case surgery was undertaken.22, 23 MIS weight bearing regimes were more uniform with all cases immediately fully weight bearing in a post-operative sandal, however this ranged from 3-6 weeks based on surgeon preference.

Table 5

Scarf Osteotomy

Study

Clinical outcomes

PROMs

Necas et al.19 (2020)

Mean reduction in 4th IM angle – 7.90

Mean reduction in 5th MTP angle – 13.60

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 59.4 – 93

AOFAS increase

P = 0.001

Coughlin satisfaction score:

79% excellent

18% Good

3% Fair

Hrubina et al23 . (2015)

Mean reduction in 4th IM angle – 7.80

Mean reduction in 5th MTP angle – 13.70

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 59.8 – 92.3

AOFAS increase P = 0.001

Coughlin satisfaction score:

74% excellent

22% Good

4% Fair

Guha et al.17 (2012)

Mean reduction in 4th IM angle – 5.80

Mean reduction in 5th MTP angle – 13.50

4th IMA reduction

P = 0.0008

5th MPJ angle reduction

P = 0.0009

Mean AOFAS increase from 54.25 – 89.58

AOFAS increase

P = 0.001

100% would refer a friend

Maher & Kilmartin18 (2010)

Mean reduction in 4th IM angle – 4.20

Mean post-op ROM 5th MTPJ – 540

4th IMA reduction

P = 0.001

Mean AOFAS increase from 44.1 – 88.1

AOFAS increase

P = 0.001

Modified satisfaction

Score:

Completely: 86%

Reservations: 11%

Dissatisfied: 3%

Would undergo same procedure:

Yes: 91%

No:9%

Seide & Petersen22 (2001)

Mean reduction in 4th IM angle – 3.50

100% pain free ROM 5th MTPJ

4th IMA reduction

P < 0.05

Mean FFSS increase from 29.5-73

FFSS = P < 0.05

Cosmetic score:

Excellent: 80%

Good: 20%

MIS

Study

Clinical outcomes

PROMs

Nunes et al.16 (2022)

Mean reduction in 4th IM angle – 5.80

Mean reduction in 5th MTP angle – 12.30

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 49.6 – 92.4

AOFAS increase

P = 0.001

Mean VAS decrease: 6.5 points

VAS decrease

P = 0.001

Coughlin satisfaction score:

83% excellent

11% Good

11% Fair

Valdivia & Thull20 (2022)

Mean reduction in 4th IM angle – 5.50

Mean reduction in 5th MTP angle – 160

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 65.8 – 95

AOFAS increase

P = 0.001

Mean VAS decrease: 6 points

VAS decrease

P = 0.001

De Vete Lima et al.15 (2020)

Mean reduction in 4th IM angle – 6.20

Mean reduction in 5th MTP angle – 9.20

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 51.3 – 94

AOFAS increase

P = 0.001

Mean VAS decrease: 6.4points

VAS decrease

P = 0.001

Ferreira et al.1 (2020)

Mean reduction in 4th IM angle – 7.70

Mean reduction in 5th MTP angle – 11.70

4th IMA reduction

P = 0.001

5th MPJ angle reduction

P = 0.001

Mean AOFAS increase from 58.8 – 93.7

AOFAS increase

P = 0.001

Mean VAS decrease: 6.6 points

VAS decrease

P = 0.001

Coughlin satisfaction score:

89% excellent

7.5% Good

3.5% Fair

Laffenetre et al.12 (2015)

Mean reduction in 4th IM angle – 4.40

Mean reduction in 5th MTP angle – 11.980

4th IMA reduction

P < 0.05

5th MPJ angle reduction

P < 0.05

100% resolution of callus

Mean AOFAS increase from 58 – 97

AOFAS increase

P < 0.05

Mean VAS decrease: 7.4 points

Coughlin satisfaction score:

97% satisfied

3% dissatisfied

Lui,21 2014

Mean reduction in 4th IM angle – 80

Mean reduction in 5th MTP angle – 170

4th IMA reduction

P < 0.0001

5th MPJ angle reduction

P < 0.0001

Mean AOFAS increase from 61.8 – 100

AOFAS increase

P < 0.0001

Coughlin satisfaction score:

100% excellent

Clinical and patient reported outcomes

All included studies assessed changes in pre and post-operative 4th IM and 5th MTPJ angles. 2 papers reviewed post-op 5th MTPJ range of motion (ROM) although failed to include any pre-operative data.18, 22 1 study vaguely reviewed pedometric changes in plantar pressures and subjectively analysed callus patterns.12 1 study utilised the “Forefoot scoring system” (FFSS) to record PROMs, all other studies uniformly employed the AOFAS.22 Change in visual analogue scale (VAS) was measured in all MIS papers and 9/11 papers recorded patient satisfaction.15, 20

All studies demonstrated statistically significant changes in pre and post-operative outcomes measures (Table 5). Pooled mean changes (Figure 3) in 4th IM angle for scarf and MIS were 5.80 and 6.20 respectively. 3/5 scarf and 6/6 MIS papers reviewed 5th MTPJ angular change demonstrating 13.60 and 13.030 respectively. AOFAS scores increased from mean 54.4 – 91 following scarf osteotomy vs mean increase 57.55 – 95.35 following MIS. Mean change in AOFAS between groups was 36.6 and 37.8 (Scarf & MIS). The study utilising FFSS demonstrated mean increase 29.5 -73. 5/6 MIS papers recorded change in VAS; mean decrease in 6.6 points. Post-operative satisfaction following each procedure was 97.5% and 92.25% (Scarf & MIS).

Figure 3

Pooled changes in outcomes

https://typeset-prod-media-server.s3.amazonaws.com/article_uploads/45e0ac77-6b1a-4c3b-b996-1547add7054e/image/c93d2f40-8ef0-4831-b0c0-316ffca15bdd-uimage.png

Complications

Complication incidence was 11% and 15.5% for scarf and MIS respectively. Revision surgery was required in 5.2% following scarf osteotomy; the most common reasons were excision of recurrent plantar corns, fixation removal. 1 patient required 2-4 weils osteotomy due to transfer metatarsalgia. 1 individual developed a deep infection requiring wound debridement. 1 wound dehiscence was noted following MIS requiring revision debridement and closure. Infection was low for both procedures; Scarf 1.7% and MIS 0.6%. The most frequently occurring complication following scarf osteotomy were recurrent intractable hyperkeratotic lesions (2%). Conversely following MIS, hypertrophic fracture callus was more common (8%) however poorly reported as a complication. Delayed union rates where similar; Scarf 1.7% vs MIS 1.9%. However, time to union was considerably different; Scarf 14 weeks vs MIS 24 weeks. Two asymptomatic non-unions were reported following MIS.

Quality assessment

Mean modified Coleman methodology scores (Table 6) for the scarf osteotomy and MIS were similar, scoring 61.8/100 and 63.6/100 respectively, indicating fair quality studies 10/11 papers. 1 MIS study scored low quality.21 MIS papers were marginally better at reporting outcomes and had larger subject numbers in 2 studies resulting in a higher mean score.1, 12 Risk of bias (Table 7) was high for both procedures. 2/5 scarf and 3/6 MIS studies demonstrated satisfactory outcome reporting however the remaining studies reported mean outcomes limiting subgroup or individual scrutiny.15, 16, 17, 21, 22 Scarf had marginally reduced attrition as 1 paper highlighted those lost to follow up and confirmed that their findings are only representative of completed outcome measures.18 60% of studies for each procedure included participants undergoing concomitant foot surgery introducing significant confounding.12, 16, 17, 18, 20, 23 Reporting bias was considerably high in MIS studies with discrepancies between authors as to whether hypertrophic fracture callus was a complication or expectation.

Table 6

Modified coleman methodology score

Study

Study size

Mean follow up

Surgical approach

Study type

Diagnostic certainty

Description of surgical technique

Description of post op rehab

Outcome criteria

Procedure of assessing outcome

Description of selection process

Total

Necas et al.19 (2020)

4

10

0

0

5

5

5

2,0,3,0

5,0,3,3

5,5,5

60/100

Guha et al.17 (2012)

0

4

0

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

53/100

Hrubina et al.23 (2015)

0

7

10

0

5

5

5

2,2,3,3

5,0,3,3

5,5,5

68/100

Maher & Kilmartin (2010)18

0

10

10

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

69/100

Seide & Petersen (2001)22

0

4

10

0

5

5

5

2,2,0,0

5,0,3,3

5,5,5

59/100

Nunes et al.16 (2022)

0

4

10

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

63/100

Valdivia & Thull20 (2022)

0

4

10

0

5

5

5

2,3,3,3

5,0,3,3

5,5,5

66/100

De Vete Lima et al.15 (2020)

0

4

10

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

63/100

Ferreira et al.1 (2020)

4

4

10

0

5

5

5

2,3,3,3

5,0,3,3

5,5,5

70/100

Laffenetre et al.12 (2015)

4

4

10

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

67/100

Lui21 (2014)

0

4

0

0

5

5

5

2,0,3,3

5,0,3,3

5,5,5

53/100

Discussion

74 years following Davies (1949) conceptualisation of tailors bunions, foot and ankle surgeons lack substantive guidance for deformity correction and have pragmatically adopted 1st ray principles to overcome this conundrum. Scarf osteotomy has remained a staple for hallux valgus reduction due to versatile and powerful correction; its rotatory capabilities making it particularly attractive for the 5th metatarsal. 18, 24, 25, 26, 27 MIS has challenged the norm and continues to be a point of contention amongst foot and ankle surgeons. Recent systematic review identified that distal 5th metatarsal osteotomies present the lowest complication rate compared to diaphyseal or basal procedures (5%, 7% and 19% respectively) albeit with the least deformity correction.6 These data are reflective of traditional open procedures and therefore cannot be easily extrapolated to MIS, leaving a substantial void within the evidence.

MIS enthusiasts claim that they can deliver comparable outcomes to open techniques with less complications, regardless of deformity classification.28 The unstable nature of ’through and through’ percutaneous osteotomies enable powerful triplanar correction with minimal insult to the soft tissue envelope arguably maintaining vascular integrity and a degree of natural constraint with the metatarsal head migrating ‘to its ideal position’. Traditional distal osteotomy is limited by a short lever arm, with research demonstrating modest reduction in IM angle despite capital fragment rotation.29 Proximal osteotomy offers the greatest corrective power through its long lever however research is limited, with recent systematic review demonstrating a conservative 2 papers.6 Perhaps unsurprisingly the scarf osteotomy has been popularised by offsetting the limitations of capital and basal procedures.

Pooled results from the 11 included studies (Figure 3) demonstrated comparable radiological reduction of deformity and patient reported outcome measures. All papers recorded statistically significant changes in 4th IM, 5th MTP angles and return of 4th IM angles to a normal range <80. Alignment, pain, and function significantly improved for both procedures according to AOFAS with MIS demonstrating a modest mean increase compared to scarf osteotomy. Patient satisfaction was high following both procedures with scarf osteotomy marginally succeeding MIS with 97.5% vs 92.25%. The researchers would caveat these results with disparity in follow up. Scarf osteotomy demonstrated 3/5 papers with mid-term review, two of which presented results following mean review 81 months compared to mean follow up 27 months following MIS.12, 18, 19, 20 Revision surgery was limited to scarf osteotomy, however studies describing revision procedures were mid-term reviews provoking uncertainty as to whether MIS patients would require revision later.

Procedure specific complications (Figure 4) differed which could have implications for clinical practice. Wound healing and infection rates were satisfactory for both however MIS demonstrated 2 (1.3%) cases of chronic regional pain syndrome (CRPS). Limiting surgical trauma is an important advantage of MIS and therefore one would consider CRPS rates to be lower than open surgery, however these assumptions are clearly flawed. Single centre study identified risk of CRPS following foot and ankle surgery 4.36%, of which 53% occurred following forefoot procedures, although it is unknown if surgery was open or percutaneous.30 Middle aged females with a history of smoking, anxiety and depression were considered the greatest risk, however a direct comparison with this study’s findings cannot be made due to methodological bias. Females of mean age 47 years represented a majority in this study however reporting bias is limiting. Recent literature reviewing the learning curve following 3rd generation percutaneous chevron / akin osteotomy for hallux valgus identified that surgeons required on average 38 cases before reaching technical proficiency; perhaps explaining the reported incidence of CRPS.31 Regulating burr temperature with intra-operative irrigation has been attributed to minimizing soft tissue necrosis however subtle variation in stab incisions was observed across MIS studies which arguably may have been responsible for nerve injury. Tourniquet use was poorly defined for both procedures. 1 study reinforced the benefit of performing surgery wet for cooling effect on the Shannon burr.1 Increased tourniquet use was observed for scarf osteotomies however this did not present any additional sequalae, and so a relationship between omitting tourniquets and reduced complication rates cannot be drawn.

Figure 4

Procedure specific complications

https://typeset-prod-media-server.s3.amazonaws.com/article_uploads/45e0ac77-6b1a-4c3b-b996-1547add7054e/image/deb9e224-455b-4939-9c58-3b918f78df2e-uimage.png

Table 7

Risk of bias

Studies

Procedure

Selection

Performance

Attrition

Reporting

Necas et al. (2020)

Scarf

Guha et al. (2012)

Scarf

Hrubina et al. (2015)

Scarf

Maher & Kilmartin (2010)

Scarf

Seide & Petersen (2001)

Scarf

Nunes et al. (2022)

MIS

Valdivia & Thull (2022)

MIS

De Vete Lima et al. (2020)

MIS

Ferreira et al. (2020)

MIS

Laffenetre et al. (2015)

MIS

Lui (2014)

MIS

[i] ★ Low risk

[ii] ● High risk

Figure 5
https://typeset-prod-media-server.s3.amazonaws.com/article_uploads/45e0ac77-6b1a-4c3b-b996-1547add7054e/image/72e65a4b-2f48-425f-94b5-24a5689ac99d-uimage.png

Maher and Kilmartin (2010) cautioned readers regarding the recurrence of intractable plantar hyperkeratosis (IPK), particularly in the cavoid foot, citing a higher revision rate of plantar condylectomy +/- lesion excision. Absence of prospective study or additional case series identifying this relationship limits external validity as this may represent sampling bias and error in patient selection. Lesion misdiagnosis within this study also cannot be excluded. Recent histopathological analysis of IPK identified 51.2% of these lesions to include human papillomavirus (HPV) which may explain the failure to resolve following deformity correction.32

Notable variations regarding osteotomy healing were identified which should be considered on a case-by-case basis. Most percutaneous osteotomies were stabilised post-operatively with external strapping, of which there was inter-surgeon variation in technique and duration. 61% of MIS complications involved symptomatic hypertrophic osteotomy callus persisting between 3-6 months; symptoms including pain, footwear irritation and delayed return to activity.12, 15, 16 This was poorly reported with divided opinion between the MIS authors as to whether this should be considered a complication or demoted to procedure expectation. This may conflict with patient expectations revolving MIS regarding minimal convalescence and rapid return to activity. Delayed union following MIS followed a similar pattern. Although little difference was observed regarding the incidence of delayed union (1.7% vs 1.9%), mean time to union significantly differed. It should be highlighted that 1 participant with protracted time to union (10 months) significantly affected results and perhaps could be considered an outlier, however other cases of delayed union required 4-6 months to consolidate and therefore all results have been documented for reader consideration.12, 16 It is acknowledged that discrepancies in healing are secondary to reduced stability and lack of internal fixation, however attitudes regarding their severity are arguably somewhat cavalier. Growing interest in MIS for surgical offloading diabetic foot ulceration has surfaced with advocates reinforcing the benefits of minimal soft tissue injury, immediate weight bearing and absence of retained hardware.33 Early outcomes are undeniably impressive with rapid ulcer healing and minimal convalescence however risk of propagating charcot neuroarthropathy is theoretically increased with delayed / non-union in neuropathic patients: One should caveat that to the authors knowledge there have been no documented incidences of MIS triggering charcot.34 Fracture is an established risk of scarf osteotomy, with early ambulation and vulnerability to stress risers through the osteotomy or fixation considered detrimental.35 Only 1 individual sustained an early post-operative fracture, perhaps unsurprisingly this series permitted immediate weight bearing. Despite healing with continued partial weight bearing, this is overshadowed by subsequent transfer metatarsalgia.18 2 studies kept patients non-weight bearing for 3 weeks however on balance, no significant benefit was gained with delayed union and fixation migration still occurring.19, 22 Fundamentally ideological post-operative guidelines are lacking.

High risk of bias and considerable methodological diversity was observed across all papers with retrospective observational bias impairing validity. 60% of each group included concomitant surgeries introducing considerable confounding, however readers should interpret this with a degree of pragmatism and appreciate these results as a reflection of real practice. Technical execution of percutaneous osteotomy varied, further confounding results and limiting validity. Reported scarf re-operative rates also deserve some scrutiny. Necas et al. (2020) identifies a reoperation rate of 8.8% following decompressive scarf, which the authors indicate as an acceptable range. This exceeds the UK average reoperation rate following orthopaedic trauma 8.6%.36 Acceptable revision rates remain ill-defined however one would caution accepting a higher incidence of revision surgery following clean elective cases. An interesting observation was the failure to prioritise post-operative stiffness as an outcome. MIS proponents frequently attribute reduced joint stiffness with percutaneous techniques however no single study demonstrated this. This may reflect attitudes that ROM at the 5th MTPJ is less important than 1st ray, however these shortcomings marry opinions that reduced arthrofibrosis following MIS is purely theoretical and limited by selection bias.2

Strengths

Debate regarding open and percutaneous foot surgery remains both topical and contentious. These results add to the greater body of research providing the most recent evidence to guide foot and ankle surgeons when considering between an open scarf or percutaneous osteotomy for reducing tailors bunion deformity. Clear rationale and study aims were identified, exploring topical themes, and providing meaningful data to support clinicians. PICO and PRISMA facilitated a transparent and exhaustive screening process to identify existing research. Structuring a well-defined inclusion/exclusion criterion enabled repeatable data extraction of key studies. All included papers were subjected to rigorous quality assessment and review of bias using established academic tools. Mean statistical analysis of shared clinical and patient reported outcomes provided measurable data to meet the primary objective of the project. Combined quantitative analysis and detailed narrative regarding individual procedure complications enabled remaining secondary objectives to be met.

Limitations

Low study numbers limited external validity, however fortunately, surgical episodes were similar for both procedures. Quality assessment identified heterogeneity and methodological shortcomings for all studies, with poorly reported patient demographics, and confounding. PROMs (AOFAS & FFSS) in all studies were unvalidated, generally favouring surgeon outcomes, poorly correlating with perceived patient importance factors, and grossly impairing internal validity.37 Appraisal of case series was not exempt from scrutiny and remains ambiguous. Modified Coleman Methodology Scores are convenient and repeatable quality assessment tools however can be ambiguous and interpretation can be subjective.14

Conclusion

Summary recommendations:

There is insufficient evidence to determine the most effective surgical procedure to reduce buniontte deformities.

  1. Grade of recommendation: B

    1. Both Scarf and percutaneous 5th metatarsal osteotomies can adequately reduce tailors bunion deformities producing comparable clinical and radiological outcomes.

  2. Grade of recommendation: B

    1. Patient satisfaction is high for both scarf osteotomy and percutaneous techniques.

  3. Grade of recommendation: B

    1. Complication rates are similar however they manifest differently between procedures and patient selection should be made on a case-by-case basis.

  4. Grade of recommendation: B

    1. Delayed union rates are comparable however time to union following percutaneous osteotomy is considerably higher. Individuals with increased risk factors for non-union should be consented accordingly.

  5. Grade of recommendation: B

    1. The ideal fixation construct and weight bearing protocol following 5th metatarsal osteotomy remains ill-defined.

  6. Grade of recommendation: B

    1. Current data suggests revision surgery is higher following scarf osteotomy.

  7. Grade of recommendation: B

    1. There is no definitive evidence that percutaneous 5th metatarsal osteotomy reduces post-operative stiffness compared to the scarf osteotomy.

  8. Grade of recommendation: B

    1. Modified Coleman methodology score.

Source of Funding

None.

Conflict of Interest

None.

References

1 

GF Ferreira TFD Santos D Oksman MVP Filho Percutaneous Oblique Distal Osteotomy of the Fifth Metatarsal for Bunionette CorrectionFoot Ankle Int20204178117

2 

A Frigg G Maquieira A Pellegino Response to “Letter regarding: Stiffness and range of motion after minimally invasive chevron-akin and open scarf-akin proceduresFoot Ankle Int20194089904

3 

B Magnan E Samaila M Bondi I Bonetti P Bartolozzi Percutaneous Distal Osteotomy of the Fifth Metatarsal for Correction of BunionetteJBJS Essent Surg Tech201222e10

4 

T Bertrand SG Parekh Bunionette Deformity: Etiology, Nonsurgical Management, and Lateral ExostectomyFoot Ankle Clin201116467988

5 

H Davies Metatarsus quintus valgusBr Med J194914606664

6 

HA Martijn IN Sierevelt S Wassink PA Nolte Fifth Metatarsal Osteotomies for Treatment of Bunionette Deformity: A Meta-Analysis of Angle Correction and Clinical ConditionJ Foot Ankle Surg20185711408

7 

JL Thomas EL Blitch DM Chaney KA Dinucci K Eickmeier LG Rubin Diagnosis and Treatment of Forefoot Disorders. Section 4. Tailor's BunionJ Foot Ankle Surg200948225763

8 

M Shimobayashi Y Tanaka A Taniguchi H Kurokawa K Tomiwa I Higashiyama Radiographic Morphologic Characteristics of Bunionette DeformityFoot Ankle Int20163733206

9 

A Ajis M Koti N Maffulli Tailor's bunion: a reviewJ Foot Ankle Surg200544323645

10 

A Deveci S Yilmaz A Firat AO Yildirim O F Oken M Gulcek An Overlooked Deformity in Patients with Hallux Valgus Tailor's BunionJ Am Podiatr Med Assoc201510532337

11 

Thomas S Roukis Dpm Facfas Phd Percutaneous and Minimum Incision Metatarsal Osteotomies: A Systematic ReviewThe Journal of foot and ankle surgery200948380387

12 

O Laffenêtre B Millet-Barbé V Darcel J Lucas Y Hernandez D Chauveaux Percutaneous bunionette correction: Results of a 49-case retrospective study at a mean 34 months’ follow-upOrthop Traumatol Surg Res2015101217984

13 

H Trnka Percutaneous, MIS and open hallux valgus surgeryEFORT Open Rev2021664328

14 

L Ramponi Y Yasui CD Murawski RD Ferkel CW Digiovanni GMMJ Kerkhoffs Lesion Size Is a Predictor of Clinical Outcomes After Bone Marrow Stimulation for Osteochondral Lesions of the Talus: A Systematic ReviewAm J Sports Med20174571698705

15 

AFdV Lima TS Baumfeld BM Maciel DS Baumfeld G Cordier GA Nunes Minimally invasive bunionette treatmentJ Foot Ankle202014214852

16 

G Nunes T Baumfeld C Nery D Baumfeld P Carvalho G Cordier Percutaneous Bunionette Correction- Retrospective Case SeriesFoot Ankle Spec20221513642

17 

AR Guha S Mukhopadhyay RH Thomas ‘Reverse’ scarf osteotomy for bunionette correction: Initial results of a new surgical techniqueFoot Ankle Surg2012181504

18 

AJ Maher TE Kilmartin Scarf Osteotomy for Correction of Tailor's Bunion: Mid- to Long-Term FollowupFoot Ankle Int201031867682

19 

L Necas M Hrubina M Skotak M Melisik P Lisy Z Cibula Bunionette deformity corrected with “shortening” scarf osteotomy of the fifth metatarsal: mid-term results of a 34-casesFoot Ankle Surg20202655416

20 

JCB Valdivia DM Thull Minimally Invasive Distal Chevron Osteotomy for Symptomatic Bunionette: Clinical and Radiologic Results of a 31-Case Retrospective StudyFoot Ankle Orthop20227224730114221099022

21 

TH Lui Percutaneous Osteotomy of the Fifth Metatarsal for Symptomatic BunionetteJ Foot Ankle Surg201453674752

22 

HW Seide W Petersen Tailor’s bunion- results of a scarf osteotomy for the correction of an increased intermetatarsal IV:V angleArch Orthop Trauma Surg20011211669

23 

M Hrubina M Skotak J Letocha V Dzupa The modified scarf osteotomy in the treatment of tailor’s bunion - midterm follow-upActa Orthop Belg20158115764

24 

FM Lopez I Reilly L Murphy The Foot and Ankle Online Journal The Scarf Osteotomy: A technique variant: The trotation scarf and Akin osteotomies for hallux valgus: Short term results of 73 casesFoot Ankle Online J201581110.3827/faoj.2015.0801.0003

25 

TE Kilmartin C O’kane The rotation Scarf and Akin osteotomy for the correction of severe hallux valgusFoot200212420312

26 

SE Smith KB Landorf PA Butterworth HB Menz Scarf versus Chevron Osteotomy for the Correction of 1-2 Intermetatarsal Angle in Hallux Valgus: A Systematic Review and Meta-analysisJ Foot Ankle Surg201251443744

27 

X Wang Q Wen Y Li C Liu K Zhao H Zhao Scarf Osteotomy for Correction of Hallux Valgus Deformity in AdolescentsOrthop Surg2019118738

28 

B Molenaers J Vanlommel P Deprez Percutaneous hardware free corrective osteotomy for bunionnette deformityActa Orthop Belg201583228491

29 

P Bewick TE Kilmartin The fifth metatarsal rotational osteotomy for the correction of tailor’s bunion deformityFoot20031341905

30 

MJ Rewhorn AH Leung A Gillespie MJ Stuart R Miller Incidence of Complex Regional Pain Syndrome after Foot and Ankle SurgeryJ Foot Ankle Surg20145332568

31 

TL Lewis PW Robinson R Ray TAJ Goff PMC Dearden MR Whitehouse The Learning Curve of Third-Generation Percutaneous Chevron and Akin Osteotomy (PECA) for Hallux ValgusJ Foot Ankle Surg20236211627

32 

FM Lopez TE Kilmartin Corn cutting in the 21st centuryPodiatry Now20161910247

33 

C Biz P Ruggieri Minimally Invasive Surgery: Osteotomies for Diabetic Foot DiseaseFoot Ankle Clin202025344160

34 

C Biz S Gastaldo M Dalmau-Pastor M Corradin A Volpin P Ruggieri Minimally Invasive Distal Metatarsal Diaphyseal Osteotomy (DMDO) for Chronic Plantar Diabetic Foot UlcersFoot Ankle Int20183918392

35 

C Coll I Beech Scarf osteotomy for reduction of tailors bunion deformities: Systematic review and meta-analysisFoot (Edinb)202355101982

36 

RC Barksfield R Coomber K Woolf A Prinja D Wordsworth D Lopez The epidemiology of reoperations for orthopaedic traumaAnn R Coll Surg Engl2015971405

37 

E Lakey KJ Hunt Patient-Reported Outcomes in Foot and Ankle OrthopedicsFoot Ankle Orthop2019432473011419852930



jats-html.xsl


This is an Open Access (OA) journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.