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Pertinent Principles In Treating Juvenile Hallux Valgus
Given the relative paucity of literature and lack of consensus on the management of juvenile hallux abducto valgus, this author reviews the existing studies on bunions in children and provides evidence-based treatment recommendations.
The treatment of several pediatric foot pathologies is controversial, primarily due to a dearth of high-level studies. The evidence on juvenile hallux abducto valgus (HAV) is relatively lacking. When the hallmark article on a subject is more than 20 years old with little new literature on the subject, it is easy to understand the lack of consensus on how to treat juvenile hallux valgus.1
Prior to discussing juvenile HAV, it is beneficial to review the pathogenesis of hallux abducto valgus as this provides clarity on the validity of treatment options. Perera and colleagues documented the ten steps in the pathogenesis of HAV.2 Intrinsic and/or extrinsic factors lead to the cascading set of events, resulting in HAV. The initial event that must occur for a patient to develop HAV is failure of the medial ligamentous structures of the first metatarsophalangeal joint (MPJ). The first metatarsal then moves medially, often due to an oblique first metatarsocuneiform joint.
The sesamoids remain in their anatomical position, meaning the proximal phalanx of the hallux will follow the sesamoids into a valgus position. The cristae of the metatarsal head erodes due to the tibial sesamoid position. A bursae then develops along the medial aspect of the first metatarsal head. The extensor and flexor hallucis longus tendons then migrate to a laterally displaced position, exacerbating the deformity.
The next step in discussing juvenile hallux valgus is the critical paradigm shift in HAV over the past five years or so, focusing on the pronation/valgus rotation of the first metatarsal.2 The concept of HAV as a triplanar deformity, put forth by Dayton and others, is changing the thought process on HAV correction.3-6 The abductor hallucis tendon displaces plantarly and no longer resists valgus rotation and lateral displacement of the hallux proximal phalanx.2 The weak dorsal capsule rotates medially due to the pronation of the first metatarsal head. Finally, elevation of the first metatarsal head occurs, resulting in lateral pressure transfer.2
A Closer Look At A Hallmark Study On Juvenile Hallux Abducto Valgus
Coughlin’s 1995 retrospective article examined 719 HAV patients from 1983 to 1994.1 Of these patients, 65 were juveniles (9 percent). Of these 65 juvenile HAV patients, 45 (60 feet) met the study inclusion criteria. The female to male ratio was 40 (52 feet):5 (8 feet). The average follow-up time was 60 months, the average age of hallux valgus onset was 11.8 years (2 to 18 years) and the average age at surgery was 15.9 years (seven feet operated with open physis).
Most patients related deformity progression (96 percent) and pain/symptoms with standard shoe gear (82 percent).1 Only 24 percent of patients related a history of constricting shoe gear. This factor combined with the average age of onset indicates that footwear is likely associated with HAV progression in adults as opposed to being the cause as juvenile HAV demonstrated no association between shoe gear and deformity. Family history (primarily maternal transmission) was a factor in 72 percent of patients. Researchers describe metatarsal protrusion distance as a risk factor for juvenile HAV.7
Coughlin demonstrated the long first metatarsal juvenile HAV group had the same incidence of bunions as the general population.1 The long first metatarsal group displayed a significantly higher distal metatarsal articular angle or, as described in the podiatric literature, a proximal articular set angle. Authors have described pes planus as a risk factor for juvenile HAV.8 The incidence of juvenile HAV in moderate or severe flatfoot was 17 percent in Coughlin’s study, which is similar to the general population.1 Coughlin found that pes planus did not have an effect on occurrence or recurrence of deformity postoperatively.
How Does Juvenile HAV Affect Quality Of Life?
Yamamoto and coworkers examined the quality of life (QOL) in symptomatic untreated adult HAV.9 The study evaluated 118 patients with symptomatic HAV (103 women and 13 men with a mean age of 63±11 years). The study’s conclusion was insightful, stating, “The QOL of untreated and symptomatic hallux valgus subjects was lower than that of the general population. All QOL and clinical evaluation parameters were not significantly or negligibly correlated with the severity of toe deformities. Surgical decision making should not be based on the severity of the deformity alone (as) patient QOL should also be carefully assessed.”
If quality of life is worse in the presence of HAV, the next logical question would be: does QOL improve with surgical correction? Saro and colleagues established that surgery for HAV improved QOL significantly.10 Torkki and coworkers’ findings were similar, concluding “Surgical osteotomy is an effective treatment for painful hallux valgus.”11 Thordarson and colleagues found patients’ Short Form (SF)-36 physical function scores, bodily pain, global foot and ankle score, and shoe comfort score all significantly improved after HAV surgical correction.12
What The Research Says About Treatment Options
In the literature for juvenile HAV, researchers have described treatment options including watchful neglect, orthoses and surgical correction. Kilmartin and colleagues examined the use of custom orthoses for juvenile HAV.13 The authors evaluated 6,000 9- and 10-year-old school children, finding 122 with radiographic confirmation of juvenile HAV. In the randomized study, children had either no treatment or treatment with custom orthoses. The study authors evaluated the children every six months for three to four years. Twenty-nine children (12 in the treatment group and 17 in the control group) were lost to follow-up. The children had X-rays after three years of treatment to evaluate their juvenile HAV deformity.
The study’s conclusion was eye-opening: “Biomechanical orthoses of the type we used should not be used to treat juvenile hallux valgus; they appear to increase the rate at which the condition progresses.”13
Torkki and coworkers also evaluated the treatment of HAV with custom orthoses, surgery and watchful neglect.11 The study utilized several outcome measurements with surgery demonstrating the best results in all categories at one year. The orthoses group also showed improvement in comparison to baseline scores and the control group especially at the six-month mark, but this improvement tapered by the one-year follow-up. The authors concluded that “ … the chevron operation is an effective treatment for patients who have a mild to moderate hallux valgus deformity and bunion pain while walking as their main symptom. Effectiveness is shown on several relevant outcome measures and the effect increases during the postsurgical year. Orthotic treatment resulted in favorable outcome at the six-month follow-up visit, after which the effect fades. Orthotic treatment may be considered an option when patients with disabling hallux valgus pain must wait for the surgery.”
Despite the evolving surgical approach to HAV correction, the Coughlin article provides valuable translatable insight to this evolution.1 The patients in the study received one of four surgical approaches (McBride bunionectomy, Austin bunionectomy, double osteotomy of various combinations or a proximal osteotomy with a distal soft tissue procedure). The overall hallux valgus angle preoperatively averaged 27.8 degrees with surgical correction reducing it to an average of 10.6 degrees. The average preoperative intermetatarsal angle was 12.2 degrees and the post-op average was 6.9 degrees. The overall recurrence rate was 10 percent with overall complication rates being higher in the group of children undergoing surgery with open epiphysis (7 of 60 feet).
The group of patients with juvenile HAV onset prior to the age of 10 exhibited more severe HAV, intermetatarsal and distal metatarsal articular angular deformities.1 The distal soft tissue procedure with proximal osteotomy procedure was the most commonly used approach owing to the high frequency of increase in the distal metatarsal articular angle. Recent research on the frontal plane component of HAV indicates this is actually the valgus rotation of the first metatarsal head.3-6
The most notable finding of the surgical groups from Coughlin’s study is that the combined approaches far outperformed the simple approaches with up to four to five times the correction ratio.1 Although none of the procedures allowed for triplanar correction, the surgical approaches that most closely did allow for triplanar correction were most successful as proved by the low distal metatarsal articular angle correction in the Austin group. This reaffirms that translational osteotomies do not allow for correction of the frontal plane deformity.
Another interesting finding from Coughlin’s study was 11 of 30 patients having unilateral surgery complained of validated stiffness based on postoperative range of motion (ROM) measurements in all four groups.1 This finding supports the theory of several authors that distal MPJ procedures are unnecessary for deformity correction in juvenile HAV and there is an unacceptable risk of post-operative joint stiffness with distal MPJ procedures.3-6,14
It is increasingly clear with the evidence-based research on the Austin bunionectomy that distal translational osteotomies are not a good choice for long-term correction in HAV surgery. Proximal options seem to be the ideal choice for juvenile HAV but only the procedure allowing for triplanar correction. The opening wedge osteotomy is a commonly accepted proximal osteotomy for juvenile HAV. The literature is mixed on this procedure with one of the more recent articles by Iyer and colleagues examining recurrence rates with proximal medial opening wedge osteotomies for moderate adult HAV.15 The overall recurrence rate was an unacceptable 64 percent with 36 percent requiring revisional surgery within one year. The authors noted, “However, given the significant early recurrences, the senior author has abandoned this technique in favor of a Lapidus procedure and has noted fewer recurrences.”
Another proximal procedure for juvenile HAV is lateral hemiepiphysiodesis. Davids and coworkers recommended this procedure in juvenile HAV patients in whom there is two more years of growth (10 years of age for females and 12 years of age for males).16 The postoperative intermetatarsal angle (13.13 degrees) and postoperative HAV (31.18 degrees) did not bode well for long-term maintenance of correction long-term.16 The answer appears to be the Lapidus procedure. This makes sense considering the Lapidus procedure allows for triplanar correction at a level closest to the apex of the deformity.
LaPorta and coworkers found the center of rotation of angulation (CORA) for HAV to be at the proximal lateral first cuneiform.17 The authors put forth the following conclusion, “We also argue that no bunion procedure exists to correct the deformity at the CORA; therefore, a combination of both angulation and translation is always necessary.”
Grace and colleagues specifically examined the Lapidus procedure for the adolescent patient.18 The study included 23 patients (30 feet) with an average age of 16.5 years. The preoperative intermetatarsal angle averaged 13.3 degrees and reduced to 5.4 degrees postoperatively. The outcomes were excellent for 25 feet, good for three feet and fair for two feet. The authors stated, “The modified Lapidus arthrodesis accomplishes two major goals not attainable with metatarsal osteotomies. This procedure will restore stability to the first ray and eliminate disturbances in weight bearing patterns of the forefoot.”
What The Author Recommends On Treating Juvenile Hallux Valgus
After reviewing the literature on juvenile HAV and based on my professional experience, I can make the following recommendations. One should delay surgical treatment of juvenile HAV until epiphyseal closure. The average first metatarsal epiphyseal closure occurs approximately at 13.7 years in girls and 15.6 years in boys.19
The Lapidus arthrodesis without opening the first MPJ is the best surgical procedure for juvenile HAV. I recommend concurrent correction of additional deformities such as equinus and pes planus. An evidence-based approach to juvenile HAV will provide consistent results for a difficult pathology.
Dr. DeHeer is a Fellow of the American College of Foot and Ankle Surgeons, a Diplomate of the American Board of Podiatric Surgery, and a member of the APMA Board of Trustees. He is also a team podiatrist for the Indiana Pacers and the Indiana Fever. Dr. DeHeer is in private practice with various offices in Indianapolis and is the founder of Step by Step Haiti.
References
1. Coughlin M. Juvenile hallux valgus: etiology and treatment. Foot Ankle Int. 1995;16(11):682-697.
2. Perera A, Mason L, Stephens M. the pathogenesis of hallux valgus. J Bone Joint Surg Am. 2011;93(17):1650-1661.
3. Dayton P, Feilmeier M, Kauwe M, Hirschi J. Relationship of frontal plane rotation of first metatarsal to proximal articular set angle and hallux alignment in patients undergoing tarsometatarsal arthrodesis for hallux abducto valgus: a case series and critical review of the literature. J Foot Ankle Surg. 2013;52(3):348-354.
4. Dayton P, Feilmeier M, Hirschi J, Kauwe M, Kauwe J. Observed changes in radiographic measurements of the first ray after frontal plane rotation of the first metatarsal in a cadaveric foot model. J Foot Ankle Surg. 2014;53(3):274-278.
5. Dayton P, Kauwe M, Feilmeier M. Is our current paradigm for evaluation and management of the bunion deformity flawed? A discussion of procedure philosophy relative to anatomy. J Foot Ankle Surg. 2015;54(1):102-111.
6. Dayton P, Kauwe M, DiDomenico L, Feilmeier M, Reimer R. Quantitative analysis of the degree of frontal rotation required to anatomically align the first metatarsal phalangeal joint during modified tarsal-metatarsal arthrodesis without capsular balancing. J Foot Ankle Surg. 2016;55(2):220-225.
7. McCluney J, Tinley P. Radiographic measurements of patients with juvenile hallux valgus compared with age-matched controls: a cohort investigation. J Foot Ankle Surg. 2006;45(3):161-167.
8. Chell J, Dhar S. Pediatric hallux valgus. Foot Ankle Clin. 2014;19(2):235-243.
9. Yamamoto Y, Yamaguchi S, Muramatsu Y, et al. Quality of life in patients with untreated and symptomatic hallux valgus. Foot Ankle Int. 2016;37(11):1171-1177.
10. Saro C, Jensen I, Lindgren U, Felländer-Tsai L. Quality-of-life outcome after hallux valgus surgery. Quality Life Res. 2007;16(5):731-738.
11. Torkki M, Malmivaara A, Seitsalo S, Hoikka V, Laippala P, Paavolainen P. Surgery vs orthosis vs watchful waiting for hallux valgus. JAMA. 2001;285(19):2474.
12. Thordarson D, Rudicel S, Ebramzadeh E, Gill L. Outcome study of hallux valgus surgery—an AOFAS multi-center study. Foot Ankle Int. 2001;22(12):956-959.
13. Kilmartin T, Barrington R, Wallace W. A controlled prospective trial of a foot orthosis for juvenile hallux valgus. Bone Joint J. 1994;76(2):210-214.
14. Shinabarger A, Ryan M, Dzurik M, Burns P. Isolated first metatarsocuneiform joint fusion for correction of metatarsus primus varus deformity and literature review. J Foot Ankle Surg. 2014;53(5):624-627.
15. Iyer S, Demetracopoulos C, Sofka C, Ellis S. High rate of recurrence following proximal medial opening wedge osteotomy for correction of moderate hallux valgus. Foot Ankle Int. 2015;36(7):756-763.
16. Davids J, McBrayer D, Blackhurst D. Juvenile hallux valgus deformity. J Pediatr Orthopaed. 2007;27(7):826-830.
17. LaPorta G, Nasser E, Mulhern J, Malay D. The mechanical axis of the first ray: a radiographic assessment in hallux abducto valgus evaluation. J Foot Ankle Surg. 2016;55(1):28-34.
18. Grace D, Delmonte R, Catanzariti A, Hofbauer M. Modified Lapidus arthrodesis for adolescent hallux abducto valgus. J Foot Ankle Surg. 1999;38(1):8-13.
19. Kelikian AS, Sarrafian SK (eds.). Sarrafian’s Anatomy of the Foot and Ankle: Descriptive, Topographic, Functional. Lippincott Williams & Wilkins, Philadelphia, 2011. Ch. 1, p. 8.
For further reading, see the DPM Blog “Current And Emerging Concepts In Treating Juvenile Hallux Valgus” by Dr. DeHeer at https://tinyurl.com/yd93aasu.