Radiographic evaluation of the hallux valgus: population study of new angular parameters

Abstracts

Estimulados pelo crescente interesse, pelos fatores intrínsecos na gênese da deformidade do hálux valgo, os autores estudaram os ângulos articulares distal do primeiro metatársico (AADM), articular proximal (AAPFP) e articular distal da falange proximal do hálux (AADFP). Para isso, avaliaram as radiografias na incidência AP em ortostase de 70 indivíduos brasileiros adultos e normais (140 pés), com idades variando de 18 a 55 anos (média 29 anos), distribuídos entre 40 indivíduos do sexo feminino (57,1%) e 30 do masculino (42,9%). A análise estatística a que se submeteram os dados indicaram como limites superiores da normalidade para a população estudada os valores de 8 graus para o AADN, 8 graus para o AAPFP e 10 graus para o AADFP.

Pé; Hálux Valgo

ARTIGO ORIGINAL

Radiographic evaluation of the Hallux Valgus: population study of new angular parameters

Caio Augusto de Souza Nery^I; Alfonso Apostólico Netto^II; Márcio Benevento^III; Cibele Réssio^IV

^IAssociate Professor at the Department of Orthopedics and Traumatology of UNIFESP-Escola Paulista de Medicina; Head of the Medicine and Sugery of the Foot

^IIOrthopedist at the Anchieta Hospital; Member of the Sector of Medicine and Surgery of the Foot - UNIFESP-Escola Paulista de Medicina

^IIIOrthopedist at the Anchieta Hospital

^IVPost-graduate course of the Department of Orthopedics and Traumatology of the UNIFESP-Escola Paulista de Medicina; Member of the Sector of Medicine and Surgery of the Foot

SUMMARY

Stimulated by the growing interest in the intrinsic factors at the genesis of the deformity of the hallux valgus, the authors studied the distal articular angle of the first metatarsal (DMAA), the proximal articular (PFPAA), and the distal articular of the proximal phalanx of the hallux (PFDAA). To do so, they evaluated the AP incidence of 70 grownup and normal Brazilian individual (140 feet) in orthostatic position with ages ranging from 18 to 55 years (29 in the average), 40 of which (57.1%) were female and 30 (42.9%) were male. The statistical analysis to wich the data were submitted pointed out as upper limts of normality, for the population studied, the following figures: 8 degrees for DMAA, 8 degrees for PFPAA and 10 degrees for PFDAA.

Key words: Foot, Hallux Valgus

INTRODUCTION

The surgical success of the correction of the hallux valgus depends on a series of factors wich enable, when they are avaluated as a whole, the orthopedist to determine the ideal method for the case at issue. There should not exist any standard treatment for the pathology but the inclusion, by summing together some correctly analyzed clinical and radiographic values, of the patient into an algorithm that picks out the best indication.

Several angular parameters have been used with a view to determine, both at the pre-operative (moment of the surgical indication) and the post-operative (moment of the result evaluation) periods, the appropriate technique, the intensity of the deformity, and the intended and achieved correction. Carefully conducted population studies point out to average values which, when used at daily work, direct our choice and evaluation. The classical parameters - hallux valgus angle, intermetatarsal angle I-II, inter-phalangeal valgus angle, tarsus-metatarsal articular angle, degree of sub-luxation of the sesamoids and relative length of the metatarsals - are still the most important ones at the radiological evaluation of the pathologies of the forefoot; nevertheless, the fact that unsatisfactory results were obtained in spite of judicious surgical indication aroused the interest of the researchers for new intrinsic ethiologic agents that might be having negative influence on the results.

The distal metatarsal articular angle of the first metatarsal (DMAA), defined as the relationship between the distal articular surface and the longitudinal axis of the first metatarsal, has been considered by the literature as the fundamental point, not only for the perfect indication of what surgical technique is to be employed, but also to achieve total congruence of the metatarsophalangeal articulation of the hallux, thus avoiding or reducing as much as possible the percentage of insufficient corrections.

Moreover, the format of the proximal phalanx of the hallux must be carefully analyzed, and the relationship of its articular surfaces with its middle axis as well. From this observation arise the proximal and distal articular angles of the proximal phalanx (PFPAA and PFDAA).

The objective of the current study is to establish the above mentioned average angular values for the population of grownup and normal Brazilian individuals so as to construct a reference source to evaluate the pathologies of the first radius.

MATERIAL AND METHOD

Radiographs were obtained at the antero-posterior incidence of 70 grownup Brazilian individual (140 feet) in orthostatic position, with ages ranging from 18 to 55 (29 in the average) and no identified complaint of general or local pathology . As to sex, the distribution was forty (57.1%) females to thirty (42.9%) males.

To measure the angles a negatoscope with florescent light and a goniometer with a degree scale were used. The method used was based upon the demarcation of the following reference points:

Distal metatarsal articular angle (first metatarsal) - DMAA

1) medial end point of the distal articular surface of the first metatarsal;

2) lateral end point of the distal articular surface of the first metatarsal;

3) diaphyseal middle axis of the first metatarsal, obtained from the geometric center of the head and the middle point of the proximal metaphysis;

4) the DMAA corresponds to the angle formed between the line uniting both ends of the distal articular surface and the perpendicular of the diaphyseal middle axis of the first metatarsal (fig.1).

Proximal articular angle of the proximal phalanx - PFPAA

1) medial end point of the distal articular surface of the proximal phalanx of the hallux;

2) lateral end point of the distal articular surface of the phalanx of the hallux;

3) diaphyseal middle axis of the proximal phalanx of the hallux obtained through the determination of the middle points of the distal and proximal metaphyses of that bone;

4) the PFPAA corresponds to the angle formed between the line uniting both ends of the proximal articular surface of the proximal phalanx of the hallux and the perpendicular to the diaphyseal middle axis of the proximal phalanx (fig.2).

Distal articular angle of the proximal phalanx - PFDAA

1) medial end point of the distal articular surface of the proximal phalanx of the hallux;

2) lateral end point of the distal articular surface of the proximal phalanx of the hallux;

3) diaphyseal middle axis of the proximal phalanx of the hallux obtained through the determination of the middle points of the proximal and distal metaphyses of that bone;

4) the PFDAA corresponds to the angle formed between the line uniting both ends of the distal articular surface of the proximal phalanx of the hallux and the perpendicular to the diaphyseal middle axis of the proximal phalanx. (fig.3).

The data obtained from the measurement of the three above mentioned angles were submitted to a statistical analysis, where they were compared as to side and sex. Student's T test was used in its bi-caudal modality and a 5% limit (a < 0.05) was fixed for the rejection of the nullity hypothesis.

RESULTS

Tables 1 and 2 gather the data referring to the measurement of the angles DMAA, PFPAA and PFDAA in males and females, respectively.

Table 3 shows the results of the statistical analysis the data were submitted to.

DISCUSSION

"The great variety of techniques described for the treatment of the deformity of the hallux valgus points out to the assumption that the problem is still short of a final solution". Hellal defined a decade ago, with this sentence, the concern of the great authors regarding the choice of the best technique to treat this deformity.

New techniques have gradually been introduced and the idea is no longer admissible of searching the "idea technique" to solve all of the cases of hallux vagus. The variability of the concurring factors to the genesis of the complex of deformities is so great that the need becomes more and more transparent to perfect the diagnosis and to combine several surgical resorts in order to act in a global way at correcting them.

It is quite remarkable that more sophisticated and complex surgical techniques have arisen, now acting on several intrinsic factors and obtaining for this reason better and better results.

The attainment of statistically similar angular values between sides and sexes has made easier the standardization of their use, what will requere, in a short period of time, that they be includes among the already accepted parameters.

CONCLUSION

We consider as upper limits of normality for the grownup Brazilian population the values: DMAA - 8 degrees; PFPAA - 8 degrees; PFDAA - 10 degress.

REFERENCES

2. Austin, D.W. & Leventen, E.O.: A new osteotomy for halux valgus: A horizontally directed V displacement osteotomy of the metatarsal head for hallux valgus and primius varus. Clin Orthop 157:25-30, 1981.

3. Baldin, M.G. & Sorto, L.A.: Distal articular set angle: etiology and X-ray evaluation. J. Am. Pediatr. Med. Assoc.

4. Boc, S.F., D´Angelantonio, A. & Grant, S.: The triplane Austin bunionectomy: a reniew and retrospective analysis. Foot Surg 30:375-382.1991.

5. Christmann, R.A.: Radiographic evaluation of the distal articular set angle. J. Am Podiatr Med. Assoc. 78:352-354, 1988.

6. Clancy, J.T., Berlim, S.J., Giordano, M,L, & Sherman, S.A.: Modified Austin bunionectomy with single screw fixation: a comparison study. Foot Surg 28:284-289, 1989.

7. Coughlin, M.: Juvenile halux valgus: etimology and treatment. Foot Ankle 16:682-697, 1995.

8. Fox, I.M., Cuttic, M. & De Marco, P.: The offset V modification of the chevron bunionectomy: a retrospective study. Foot Surg 31:615-620, 1992.

9. Hanft, J.R., Kashuk, K.B., Bonner, A.C., Toney, M. & Shabler, J.: Rigid internal fixation of the Austin chevron osteotomy with Herbert screw fixation: a retrospective study. Foot Surg 31:512-518, 1982.

10. Hardy, R.H. & Clapham, J.C.R.: Observation on hallux valgus: based on a controlled serie. J. Bone Joint Surg 33 B:376-391, 1951.

11. Harris R. & Beath, T.: The short first metatarsal. Its incidence and clinical significance. J Bone Joint Surg 31:533-565, 1949.

12. Jahss, M.H.: hallux valgus: further considerations the first metatarsal head. Foot Ankle. 2:1, 1981.

13. La Porta, G., Mellilo, T. & Olinsky, D.: X-ray evaluation of hallux valgus deformity. 64:544-366.1974.

14. Mcdonald, K.C., Durrant, M.N., Drake, R.. & Paolercio, N.L.: Retrospective analysis of Akin-Austin bunionetomies on patientes over fifty years of age. Foot Surg 27:545-555, 1988.

15. Pigott, H.: The natural history of hallux valgus in adolescence and early adult life. J Bone Joint Surg 42: 749-760, 1960.

16. Richardson, E., Graves, S., Macclure, J. & Boone, R.: First metatarsal head-shaft angle: A method of determination. Foot Ankle 14:181-185, 1993.

17. Sorto, L., Balding, M. & Weil, L.S.: Hallux abductus interphalangeus, aetiology, x-ray evaluation and treatment. J.A.P.A. 66: 384, 1976.

18. Smith, R., Reynolds, J. & Stewart, M.: Hallux valgus assessment: report of research of American Orthopaedic Foot and Ankle Society. Foot Ankle 5:92-103, 1984.

19. Vitteto, D.A., Saltzman, C.L., Krieg, J.C. & Brown, T.D.: Validity and reliability of the first distal metatarsal articular angle. Foot Ankle 15:541-547, 1994.

Work carried out at the Department of Orthopedics and Traumatology of the Federal University of São Paulo - Escola Paulista de Medicina (Service of Professor Dr. José Laredo Filho), and at the Anchieta Hospital (São Paulo).

• 2. Austin, D.W. & Leventen, E.O.: A new osteotomy for halux valgus: A horizontally directed V displacement osteotomy of the metatarsal head for hallux valgus and primius varus. Clin Orthop 157:25-30, 1981.
• 3. Baldin, M.G. & Sorto, L.A.: Distal articular set angle: etiology and X-ray evaluation. J. Am. Pediatr. Med. Assoc.
• 4. Boc, S.F., D´Angelantonio, A. & Grant, S.: The triplane Austin bunionectomy: a reniew and retrospective analysis. Foot Surg 30:375-382.1991.
• 5. Christmann, R.A.: Radiographic evaluation of the distal articular set angle. J. Am Podiatr Med. Assoc. 78:352-354, 1988.
• 6. Clancy, J.T., Berlim, S.J., Giordano, M,L, & Sherman, S.A.: Modified Austin bunionectomy with single screw fixation: a comparison study. Foot Surg 28:284-289, 1989.
• 7. Coughlin, M.: Juvenile halux valgus: etimology and treatment. Foot Ankle 16:682-697, 1995.
• 8. Fox, I.M., Cuttic, M. & De Marco, P.: The offset V modification of the chevron bunionectomy: a retrospective study. Foot Surg 31:615-620, 1992.
• 9. Hanft, J.R., Kashuk, K.B., Bonner, A.C., Toney, M. & Shabler, J.: Rigid internal fixation of the Austin chevron osteotomy with Herbert screw fixation: a retrospective study. Foot Surg 31:512-518, 1982.
• 10. Hardy, R.H. & Clapham, J.C.R.: Observation on hallux valgus: based on a controlled serie. J. Bone Joint Surg 33 B:376-391, 1951.
• 11. Harris R. & Beath, T.: The short first metatarsal. Its incidence and clinical significance. J Bone Joint Surg 31:533-565, 1949.
• 12. Jahss, M.H.: hallux valgus: further considerations the first metatarsal head. Foot Ankle. 2:1, 1981.
• 13. La Porta, G., Mellilo, T. & Olinsky, D.: X-ray evaluation of hallux valgus deformity. 64:544-366.1974.
• 14. Mcdonald, K.C., Durrant, M.N., Drake, R.. & Paolercio, N.L.: Retrospective analysis of Akin-Austin bunionetomies on patientes over fifty years of age. Foot Surg 27:545-555, 1988.
• 15. Pigott, H.: The natural history of hallux valgus in adolescence and early adult life. J Bone Joint Surg 42: 749-760, 1960.
• 16. Richardson, E., Graves, S., Macclure, J. & Boone, R.: First metatarsal head-shaft angle: A method of determination. Foot Ankle 14:181-185, 1993.
• 17. Sorto, L., Balding, M. & Weil, L.S.: Hallux abductus interphalangeus, aetiology, x-ray evaluation and treatment. J.A.P.A. 66: 384, 1976.
• 18. Smith, R., Reynolds, J. & Stewart, M.: Hallux valgus assessment: report of research of American Orthopaedic Foot and Ankle Society. Foot Ankle 5:92-103, 1984.
• 19. Vitteto, D.A., Saltzman, C.L., Krieg, J.C. & Brown, T.D.: Validity and reliability of the first distal metatarsal articular angle. Foot Ankle 15:541-547, 1994.

Publication Dates

• Publication in this collection
  17 May 2006
• Date of issue
  June 2001