Improving calf muscle strength in patients with spastic equinovarus deformity by transfer of the long toe flexors to the Os calcis.

The split tibialis anterior tendon transfer (SPLATT), Achilles tendon lengthening, and toe flexor release are proven and effective procedures for correcting a spastic equinovarus deformity of the foot. Paresis is a prominent feature of upper motoneuron syndrome. Lengthening the Achilles tendon, although necessary to correct the equinus, further weakens the gastrocnemius-soleus muscle group. The calf paresis commonly results in the need for an ankle-foot orthosis (AFO) during ambulation. Previous studies have shown that despite the correction of the equinovarus deformity, only one third of patients were able to ambulate without an AFO. The need for continued use of an AFO was because of insufficient calf strength to stabilize the tibia during late stance when the body mass is anterior to the ankle joint. This study prospectively evaluated the results of transfer of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) to the os calcis in 30 patients. The transfer was done in an effort to augment the strength of the gastrocnemius-soleus muscle complex. Twenty-five patients in group I (the control group) underwent SPLATT, Achilles tendon lengthening, and toe flexor release. Thirty patients in group II (the study group) underwent the identical procedures plus the additional FHL and FDL transfer to the os calcis. Postoperatively, the varus and toe flexion deformities were corrected in all feet. In group II, two feet had a mild residual equinus that did not interfere with ambulation. Of the 11 patients who were not independent community ambulators in group I, 7 (64%) improved ambulatory status by at least one level after surgery. Of the 15 patients who were not independent community ambulators in group II, 14 (93%) improved ambulatory status by at least one level after surgery. In group I, 10 of 25 (40%) of the patients were brace free at follow-up. In group II, 21 of 30 (70%) were brace free at follow-up (c2, P =.025). These results indicate that the addition of an FHL and FDL transfer to the os calcis at the time of SPLATT, Achilles tendon lengthening, and toe flexor release improves calf strength and allows greater increase in function and less reliance on orthotics.

A technique for measuring absolute toe pressures: evaluation of pressure-sensitive film techniques.

Although a number of pathologies of the forefoot in ballet dancers on pointe have been described, pressures and deforming forces have not been adequately measured. To evaluate the possible use of pressure-sensitive film (PSF) in measuring the pressures on the external soft tissues in such a confined space as the dancer's toe shoe, it was tested and calibrated with 20 cadaver toes. Each cadaver toe was internally stabilized and loaded longitudinally against PSF on a flat surface. The resultant films were analyzed with a video imaging system and the pressures and total forces were determined. Results showed that the linearity of the PSF to pressure had a regression value of 0.98. By using two sensitivity ranges of films, the total force measured by the PSF was found to be within 10% of the known applied force on each toe. The PSF, therefore, may very well be a useful and accurate method of measuring external soft tissue pressures on the forefoot.

Analysis of the forefoot on pointe in the ballet dancer.

The forefoot positions of nine ballet dancers standing on pointe were determined using a mold technique. These molds revealed three positions of the toes: (1) no crossing of the three medial toes; (2) crossing of the third toe behind the second; and (3) crossing of the hallux partially in front of the second. Almost half of all the toes seen on the molds had some deformation of the toenails. These molds also indicated a wide variability in the amount and location of contact between the shoes and toes.