Sensitivity of Plantar Pressure and Talonavicular Alignment to Lateral Column Lengthening in Flatfoot Reconstruction.

SLR - August 2013 - James P. Callahan

Reference: Oh Irvin, Imhauser C, Choi D, Williams B, Ellis S, Deland J.  Sensitivity of Plantar Pressure and Talonavicular Alignment to Lateral Column Lengthening in Flatfoot Reconstruction.  J Bone Joint Surg Am, 95:1094-1100; 2013.

Scientific Literature Review
 

Reviewed by: James P. Callahan, DPM
Residency Program: Inova Fairfax Hospital, Falls Church, VA

Podiatric Relevance: Surgical correction of pes plano valgus can be approached with myriad procedures. Lateral column lengthening (LCL), in particular via the Evans osteotomy, is frequently employed for the correction of both pediatric and adult deformities. The magnitude of correction obtained is directly related to the size of the graft and it is entirely at the discretion of the surgeon to determine the upper threshold for correction without ‘over-correcting.’ The establishment of a causal relationship between graft size and the correction visualized in the medial column in conjunction with increased lateral forefoot pressures would be invaluable to the foot and ankle surgeon to maximize correction and limit complications.
 

Methods: A cadaveric study was employed to determine the relationship between graft size used for LCL with associated changes in lateral plantar pressures and talonavicular alignment. The primary objective was to determine if a linear relationship existed between segmental increases in graft size and increases in plantar pressures. Eight specimens were analyzed with kinematic and plantar pressure data in neutral position, following creation of a flatfoot and after lengthening with six, eight and 10mm grafts.

Results: In comparison to the simulated flat foot, the LCL showed a linear increase in lateral forefoot mean plantar pressure, peak pressure, and contact area. Deformity of the talonavicular alignment in the sagittal and axial plane was also reduced with the six, eight, and 10mm grafts, with the data from the six millimeter graft correlating closest to the neutral or control position prior to creation of the flatfoot deformity.

Conclusions: The magnitude of correction and corresponding increases in lateral plantar pressure from a two millimeter variation in LCL fully elucidates the power of the Evans procedure. The results indicate the need for judicial correction and thorough contemplation by the foot and ankle surgeon in regards to the extent of LCL. Further study in defining optimal length patterns associated with the greatest degree of angular correction while limiting increases in lateral plantar pressures will maximize the effectiveness of the procedure. Clinical analysis would provide the additional benefit of the in-vivo interaction of the entire musculoskeletal apparatus rather than selective isolation of one muscle group.