A randomised controlled trial of laser scanning and casting for the construction of ankle–foot orthoses

Abstract

Background: Three-dimensional laser scanning has been used for patient measurement for cranial helmets and spinal braces. Ankle–foot orthoses are commonly prescribed for children with orthopaedic conditions. This trial sought to compare ankle–foot orthoses produced by laser scanning or traditional plaster casting. Objectives: Assessment of the effectiveness and efficiency of using laser scanning to produce ankle–foot orthoses. Study design: Randomised controlled trial with blinding of orthotists and patients to the construction technique used. Methods: A randomised double-blind trial comparing fabrication of ankle–foot orthoses from casts or laser scans. Results: The time spent in the rectification and moulding of scanned ankle–foot orthoses was around 50% less than for cast ankle–foot orthoses. A non-significant increase of 9 days was seen in the time to delivery to the patient for laser scanning with computer-aided design and computer-aided manufacturing. There was a higher incidence of problems with the scan-based ankle–foot orthoses at delivery of the device, but no difference in how long the ankle–foot orthoses lasted. Costs associated with laser scanning were not significantly different from traditional methods of ankle–foot orthosis manufacture. Conclusion: Compared with conventional casting techniques, laser scan–based ankle–foot orthosis manufacture did not significantly improve either the quality of the final product or the time to delivery. Clinical relevance Ankle–foot orthoses (AFOs) are a common requirement for chronic neurological conditions during childhood. Improved efficiency of provision of AFOs would benefit children and families by reducing the delay in provision of devices and would benefit the health service by making best use of valuable orthotist time.

Comparison of 3D scanning versus traditional methods of capturing foot and ankle morphology for the fabrication of orthoses: a systematic review

“…The six studies included 189 adults (102 female, 86 male, and 1 unspecified) [ 23 – 25 , 27 , 28 ] and 134 children (59 girls, 75 boys) [ 23 , 24 , 26 , 27 ]. The mean age and SD of the participants in the included studies were 23.8 years, SD 3.6 [ 23 ], 35.4 years, SD 13.6 [ 24 ], 42.8 years, SD 11.4 [ 27 ], males 21.2 years, SD 2.1 and females 21 years SD 5.9 [ 25 ], males 10.7 years SD 4.9 females 9.8 years SD 4.1 [ 26 ] and not reported [ 28 ]. The sample size for the studies were n = 15 [ 23 ], n = 21 [ 24 ], n = 22 [ 27 ], n = 130 [ 25 ], n = 134 [ 26 ] and n = 1 [ 28 ].…”

“…The mean age and SD of the participants in the included studies were 23.8 years, SD 3.6 [ 23 ], 35.4 years, SD 13.6 [ 24 ], 42.8 years, SD 11.4 [ 27 ], males 21.2 years, SD 2.1 and females 21 years SD 5.9 [ 25 ], males 10.7 years SD 4.9 females 9.8 years SD 4.1 [ 26 ] and not reported [ 28 ]. The sample size for the studies were n = 15 [ 23 ], n = 21 [ 24 ], n = 22 [ 27 ], n = 130 [ 25 ], n = 134 [ 26 ] and n = 1 [ 28 ]. Five studies included healthy participants [ 23 – 25 , 27 , 28 ] while only one study included participants who were prescribed with rigid and/or hinged AFOs although their conditions were not reported [ 26 ] (Table 1 ).…”

“…The sample size for the studies were n = 15 [ 23 ], n = 21 [ 24 ], n = 22 [ 27 ], n = 130 [ 25 ], n = 134 [ 26 ] and n = 1 [ 28 ]. Five studies included healthy participants [ 23 – 25 , 27 , 28 ] while only one study included participants who were prescribed with rigid and/or hinged AFOs although their conditions were not reported [ 26 ] (Table 1 ).…”

“…Two studies compared 3D scanning with both plaster casting and foam impression [ 23 , 27 ]. Three studies compared 3D scanning to plaster casting methods only [ 24 , 26 , 28 ]. One study compared 3D scanning measurement to digital and ink footprints as well as digital calliper measurements [ 25 ].…”

“…Two studies compared the time required to 3D scan versus plaster cast the foot and ankle (Table 6 ) [ 26 , 28 ]. In one study, the overall time taken for 3D scanning (11.1 mins, SD 9.5) and casting (12.5 mins, SD 4.9) was similar ( p = 0.056) [ 26 ].…”