Grice arthrodesis in the treatment of valgus feet in children with myelomeningocele: a 12.8-year follow-up study

Abstract

Purpose: Neurological deficit resulting in the lack of motor control in children with myelomeningocele often leads to a valgus position of the feet and ankles, usually in combination with planovalgus and pronation of the forefoot. The purpose of the study was to evaluate long-term patient satisfaction and clinical effects in ambulating children with lumbosacral myelomeningocele after having performed a Grice arthrodesis of a valgus unstable foot. The clinically most relevant radiographic measurements, such as the frontal and lateral talo-calcaneal angles, were used to evaluate the anatomical effects of the surgery, whereas the main research question was to reveal the patient satisfaction and usefulness of the procedure.

Methods: The modified Grice-Green extraarticular subtalar arthrodesis was performed by the same surgeon on one standing and 22 walking patients (12 female) with lumbosacral myelomeningocele and valgus instability during the period 1985-1999. Twelve patients had bilateral surgery, giving a total of 35 operated feet. The patients attended a thorough check-up at a mean of 12.8 years (standard deviation [SD] +/- 3.2, range 7.7-20.2 years) after surgery. The mean age at surgery was 6.6 years (SD +/- 1.8) and at follow-up 19.4 years (SD +/- 3.8). Functional parameters, such as walking ability, pain and skin problems, and the need for braces and supportive orthopaedic shoes were noted at the follow-up interview. The parents were interviewed along with the patients in order to obtain all of the necessary information. Loaded radiographs in the lateral and frontal planes were taken of both feet and ankles pre-operatively and at follow-up, except for pre-operative radiographs in six patients that were not loaded and, thus, not included, except for the assessment of ankle valgus. Ankle valgus was assessed from lateral and frontal views of the ankle on a scale from grade 0 to grade 3 according to Malhotra. Frontal and lateral talo-calcaneal angles were measured for the assessment of subtalar varus or valgus. Lateral talo-first-metatarsal (Meary's) angles were measured to investigate the longitudinal arches of the feet.

Results: The mean lateral talo-calcaneal angle was reduced significantly (P < 001) from 55.1 degrees (SD +/- 8.9) to 38.8 degrees (SD +/- 8.1). The mean frontal talo-calcaneal angle was reduced from 24.7 degrees (SD +/- 9.7) pre-operatively to 16.6 degrees (SD +/- 6.3) at follow-up (P < 0.001). The mean lateral talo-first-metatarsal angle improved significantly from -16.1 degrees (SD +/- 24.7) pre-operatively to 0.9 degrees (SD +/- 15.1) at follow-up (P = 0.0015). The calcaneal pitch did not change significantly. In general, ankle valgus worsened during follow-up time, but not significantly (P = 0.113). The visual analogue scale (VAS) score of patient satisfaction improved significantly from 3.7 (SD +/- 1.7) prior to surgery to 7.2 (SD +/- 1.5) at follow-up (P < 0.005). Nineteen patients (83%) were satisfied with the surgery and would thus recommend the procedure.

Conclusions: Based on the radiological findings and patient satisfaction, the patients participating in this study benefited from having had Grice arthrodeses performed on their valgus unstable feet. The results indicate good long-term correctional effect on valgus deformity after Grice arthrodesis, as the talo-calcaneal and talo-first-metatarsal angles improved significantly. A great majority of the patients were content with the surgery, and none claimed that any residual deformity was the cause for any reduced ability to ambulate.

Fig. 1

The Grice–Green procedure. Two cortical bone blocks are harvested from the lateral proximal part of the tibia and inserted into the tarsal tunnel. Implants for fixation are usually not necessary

Fig. 2

Classification of ankle valgus according to Malhotra et al. [17]. The degree of ankle valgus is determined based on the level of the fibular growth plate

Fig. 3

Graft resorption and apparent lack of subtalar fusion 9 years after Grice extraarticular subtalar arthrodesis. The patient had no complaints and the foot appeared to be valgus stable

Fig. 4

Example of the course of the foot after a Grice arthrodesis was performed in a 5-year-old girl. The radiographs were taken: a prior to surgery, b post-operatively and c at 13 years follow-up. The fourth toe was amputated due to a pressure sore

Fig. 5

Lateral view of a Grice arthrodesis pre-operatively, post-operatively after union and at 9 years follow-up

Fig. 6

Patient unhappy with their left foot due to valgus instability at Chopart’s joint 9 years after Grice–Green arthrodesis