Authors (including presenting author) :
Tsoi VLM(1), Chan CPS(1), Lo SHT(1), Sun KHK(1), Ma YWT(1), Poon DWF(1), Ho PC(2)
Affiliation :
(1) Department of Occupational Therapy, Prince of Wales Hospital, Hong Kong, (2) Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong
Introduction :
Mallet finger is the disruption of the terminal extensor at its exertion on the distal phalanx resulted from direct trauma to the finger tip. Most cases of a mallet finger of the teninous orgin is treated by immobilising the DIP joint in an extended position using a thermopalstic splint. However, it is still controversial that whether the immobilisation of the PIP joint can promote tendon healing.
Objectives :
This is a prospective single blinded (blinded assessors) randomized study with three treatment groups to compare 3 different types of thermoplastic splints in treating mallet finger injury conservatively.
Methodology :
From June 2020 to December 2021, 30 patients with acute closed mallet injury were recruited into this study for a 6-week splinting program. They were randomly allocated into 3 groups with different design of splints in keeping PIP joint either free of immobilized in various angles for initial two weeks. These 3 groups were (i) long mallet splint with PIP joint immobilized at 40o flexion, (ii) long mallet splint with PIP joint immobilized at 60o flexion, and (iii) short mallet splint with free PIP joint. All subjects were then given a short mallet splint for next 4 weeks. Primary outcomes were active DIP joint flexion and extensor lag, pain and the Crawford scale. Assessments were performed at 2 time points; at initial intake and at the end of week 12.
Result & Outcome :
At the final evaluation, 3 groups with different splint designs showed significant difference in reducing DIP joint extension lag (mean difference= 23.2, p<.001). All patients could achieve normal active DIP joint flexion and extension without pain. However, no between group differences were identified on all the clinical measures and function, except existence of swan-neck deformity. Among 3 groups, long mallet splint with PIP joint immobilized at a flexion angle of 40 o could significantly reduce their swan-neck deformity (x2= 4.286, p=.038). In conclusion, all 3 groups can effectively help patients to reduce DIP joint extension lag after a 6-week splinting program. Long mallet splint with PIP joint immobilized at 40 o flexion and DIP joint in slight hyperextension could correct early developed swan-neck deformity.
