title: Does thumb immobilization contribute to scaphoid fracture stability?
abstract: Immobilization protocols for nondisplaced scaphoid fractures have included the elbow, wrist, and thumb. This study attempts to demonstrate whether or not immobilization of the thumb makes a difference in preventing motion at the scaphoid fracture site. Using six fresh frozen forearm specimens, a transverse waist scaphoid fracture was created through a dorsal approach. Metallic markers were imbedded on either side of the fracture. Sutures were secured to the flexor pollicus longus (FPL) and extensor pollicus longus (EPL). Each specimen was loaded in extension and flexion by attaching 50-g weights to the EPL and FPL, first with no casting, then with a short arm cast, and finally a short arm thumb spica cast. Angulation and displacement at the fracture site were measured in the coronal, sagittal, and axial planes utilizing image reconstructions from computed tomography. One-way ANOVA with repeated measures and Tukey-Kramer multiple comparison test post hoc analysis were used for statistical evaluation. There was no significant difference in fracture angulation or rotation between spica and short arm casts. There was a significant difference in angulation and rotation in all three planes when comparing between casting and no casting, p < 0.05. In our cadaveric model, wrist immobilization is crucial for nondisplaced scaphoid waist fractures, and short arm casting was just as effective as thumb spica casting in preventing fracture displacement.
authors.affiliation: Department of Orthopaedic Surgery, Loma Linda University Medical Center, 11406 Loma Linda Drive, Suite 218, Loma Linda, CA, USA.
authors.forename: J Mark
authors.initials: JM
authors.lastname: Schramm
authors.forename: Minhthy
authors.initials: M
authors.lastname: Nguyen
authors.forename: Montri D
authors.initials: MD
authors.lastname: Wongworawat
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kjellin
references.citation: J Bone Joint Surg Am. 1989 Mar;71(3):354-7
references.pmid: 2925707
references.citation: J Bone Joint Surg Am. 1989 Dec;71(10):1560-5
references.pmid: 2687282
references.citation: Acta Orthop Scand. 1973;44(6):679-89
references.pmid: 4770136
references.citation: Hand Clin. 2001 Nov;17(4):541-52
references.pmid: 11775467
references.citation: Clin Orthop Relat Res. 1980 Jun;(149):83-9
references.pmid: 7408321
references.citation: J Hand Surg Am. 2007 Jan;32(1):61-6
references.pmid: 17218177
references.citation: J Hand Surg Am. 2004 May;29(3):481-8
references.pmid: 15140493
references.citation: J Hand Surg Am. 1980 Sep;5(5):508-13
references.pmid: 7430591
references.citation: Clin Orthop Relat Res. 1980 Jun;(149):90-7
references.pmid: 6996886
references.citation: Acta Orthop Scand. 1975 Nov;46(5):737-43
references.pmid: 1199711
references.citation: Instr Course Lect. 2003;52:197-208
references.pmid: 12690849
references.citation: J Bone Joint Surg Br. 1990 Jan;72(1):98-101
references.pmid: 2298805
references.citation: J Bone Joint Surg Br. 1991 Sep;73(5):828-32
references.pmid: 1894676
references.citation: Skeletal Radiol. 1983;9(3):189-91
references.pmid: 6844937
references.citation: Clin Orthop Relat Res. 2003 Jun;(411):255-9
references.pmid: 12782882
references.citation: Clin Orthop Relat Res. 1988 May;(230):30-8
references.pmid: 3284681
references.citation: J Bone Joint Surg Br. 1999 Jan;81(1):91-2
references.pmid: 10068011