Comparison of the Calcaneal Pitch Angle and Modified Projection Area Per Length Squared Method for Medial Longitudinal Arch Evaluation of the Foot

Abstract

Objective: To compare the calcaneal pitch angle (CPA) values measured on direct lateral radiographs of feet, and the modified projection area per length squared (PAL), which was calculated as a new method for the evaluation of the medial longitudinal arch (MLA) of the foot. Material and Methods: Direct lateral radiographs of patients who had weightbearing feet radiographies for any reason except trauma were retrospectively obtained from the archives. Direct lateral radiographs of the feet were printed and a transparent sheet was placed on it. A straight line was drawn between the most plantar process of the calcaneus and the head of the first metatarsal bone for the calculation of the PAL of the MLA. Two semilunar arcs were drawn upon this straight line. PAL1 and PAL2 were estimated using a point-counting technique. The CPA, lateral talo-calcaneal angles (LTCA), and talo-first metatarsal angles (TFMA) were measured. The correlations between PAL1, PAL2 of right and left feet and CPA, LTCA, and TFMA were explored. Results: Fifty patients (27 females, 23 males) with a mean age of 40.12 (4-78) years were evaluated. Significant correlations were detected between PAL1, PAL2 and CPA, and TFMA for both right and left feet (p<0.05). Conclusion: A significant correlation was detected between the modified PAL method as a new technique and the standard CPA method for MLA evaluation. The PAL method is suggested as a simple and practical method for MLA evaluation. Turkish Başlık: Ayağın Mediyal Longitudinal Arkının Değerlendirilmesinde Kalkaneal Pitch Açısı İle Modifiye Projeksiyon Alanı Metodunun Karşılaştırılması Anahtar Kelimeler: Mediyal longitudinal ark, kalkaneal pitch açısı, projeksiyon alanı Amaç: Ayağın mediyal longitudinal arkının (MLA) değerlendirilmesinde ayak direkt lateral grafisinde ölçülen kalkaneal pitch açısı (KPA) değerleri ile alternatif metod olarak modifiye projeksiyon alanı (PA) metodunun karşılaştırılması. Materyal, Metod: Travma dışında herhangi bir nedenle basarak ayak grafisi çekilmiş hastaların lateral direkt ayak grafileri arşivden tarandı. Ayak direkt lateral radyografileri basıldı ve üzerine transparan kağıt yerleştirildi. MLA'nın PA değerini hesaplamak için kalkaneusun en plantar çıkıntısı ile birinci metatarsal kemiğin başı arasına düz çizgi çizildi. Bu düz çizgi üzerinde iki semilunar ark çizildi. PA1 ve PA2 nokta sayma tekniği ile belirlendi. KPA, lateral talo kalkaneal açı (LTKA) ve talo-birinci metatarsal açı (TBMA) ölçüldü. Sağ ve sol ayak için PA1, PA2 ile KPA, LTKA ve TBMA arasındaki korelasyonlar araştırıldı. Bulgular: Yaş ortalaması 40.12 (4-78) yıl olan, elli hasta (27 kadın, 23 erkek) değerlendirildi. Hem sağ ve hem de sol ayak için PA1, PA2 ve KPA ve TBMA arasında anlamlı korelasyon olduğu saptandı (p<0,05). Sonuç: MLA'ın değerlendirilmesinde standart bir metod olan KPA ile yeni bir teknik olan modifiye PA arasında anlamlı ilişki olduğu saptandı. PA metodu, MLA değerlendirilmesinde basit ve pratik bir yöntem olarak önerilebilir.

Keywords

• Medial longitudinal arch, calcaneal pitch angle, projection area per length squared

Comparison of the Calcaneal Pitch Angle and Modified Projection Area Per Length Squared Method for Medial Longitudinal Arch Evaluation of the Foot

Öz

References

1. Moore KL, Dalley AF. Clinically Oriented Anatomy, Lippincot Wil- liams and Wilkins, Canada, Fourth edition, 1999.p.640.
2. Standring S (Editor). Gray’s Anatomy, The Anatomical Basis of Clinical Practice, Section editor; Vishy Mahadevan, Section: Pel- vic girdle and lower limb, Churchill Livingstone Elsevier, China, Fortieth edition, 2008.p.1450.
3. Kanatlı U, Yetkin H, Cila E. Footprint and radiographic analysis of the feet. J Pediatr Orthop 2001;21:225-8. [CrossRef]
4. Staheli LT, Chew DE, Corbett M. The longitudinal arch. A sur- vey of eight hundred and eighty-two feet in normal children and adults. J Bone Joint Surg Am 1987;69:426-8.
5. Viladot A. Surgical treatment of the child’s flatfoot. Clin Orthop Relat Res 1992;283:34-8.
6. Volpon JB. Footprint analysis during the growth period. J Pediatr Orthop 1994;14:83-5. [CrossRef]
7. Saltzman CL, Nawoczenski DA, Talbot KD. Measurement of the medial longitudinal arch. Arch Phys Med Rehabil 1995;76:45-9. [CrossRef]
8. Yalçin N, Esen E, Kanatli U, Yetkin H. Evaluation of the medial longitudinal arch: a comparison between the dynamic plantar pressure measurement system and radiographic analysis. Acta Orthop Traumatol Turc 2010;44:241-5. [CrossRef]

9. Kuru O, Sahin B, Kaplan S. Alternative approach to evaluating lumbar lordosis on direct roentgenograms: projection area per length squared. Anat Sci Int 2008;83:83-8. [CrossRef]
10. Sahin B, Emirzeoglu M, Uzun A, Incesu L, Bek Y, Bilgic S, et al. Unbiased estimation of the liver volume by the Cavalieri principle using magnetic resonance images. Eur J Radiol 2003;47:164-70. [CrossRef]
11. Simons GW. A standardized method for the radiographic evalua- tion of clubfeet. Clin Orthop Relat Res 1978;135:107-18.
12. Vanderwilde R, Staheli LT, Chew DE, Malagon V. Measurements on radiographs of the foot in normal infants and children. J Bone Joint Surg Am 1988;70:407-15.
13. Lo HC, Chu WC, Wu WK, Hsieh H, Chou CP, Sun SE, et al. Com- parison of radiological measures for diagnosing flatfoot. Acta Ra- diol 2012;53:192-6. [CrossRef]
14. Younger AS, Sawatzky B, Dryden P. Radiographic assessment of adult flatfoot. Foot Ankle Int 2005;26:820-5.
15. Sensiba PR, Coffey MJ, Williams NE, Mariscalco M, Laughlin RT. Inter-and intraobserver reliability in the radiographic evaluation of adult flatfoot deformity. Foot Ankle Int 2010;31:141-5. [CrossRef]
16. Chen CH, Huang MH, Chen TW, Weng MC, Lee CL, Wang GJ. The correlation between selected measurements from footprint and radio- graph of flatfoot. Arch Phys Med Rehabil 2006;87:235-40. [CrossRef]
17. Coughlin MJ, Kaz A. Correlation of Harris mats, physical exam, pictures, and radiographic measurements in adult flatfoot defor- mity. Foot Ankle Int 2009;30:604-12. [CrossRef]
18. Wearing SC, Urry S, Perlman PR, Dubois P, Smeathers JE. Serial measurement of calcaneal pitch during midstance. J Am Podiatr Med Assoc 1999;89:188-93.