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Three Part Question

In [an adult patient presenting with an acute mallet finger suitable for non-operative treatment] what is [the best method of treatment] to [facilitate an optimum outcome]?

Clinical Scenario

A middle aged man presents with a painful right index finger after stubbing it on a door. He clinically has a classic mallet deformity with swelling and tenderness over the dorsum of the distal interphalangeal joint and loss of active extension. Radiographs confirm there is no fracture. You wonder how this can be best managed non-operatively.

Search Strategy

OVID interface on the world wide web. 1966 – April 2010
[({mallet finger OR drop finger OR baseball finger.mp} AND {extensor tendon AND zone one.mp} AND {extensor tendon AND distal interphalangeal joint}]
LIMIT to English

Search Outcome

577 papers found of which 573 were either irrelevant or of insufficient quality for inclusion.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Pike J, et al. April 2010 Canada	87 patients with 87 mallet fingers. Adult patients only, acute injuries only, bony (small fragment ie Doyle Type 1) and soft tissue types, no thumbs. Randomised to one of 3 splint types: volar padded aluminum splint, dorsal padded aluminum splint or custom made thermoplastic splint. Splints were continued for 6 weeks full-time.	PRCT	Clinical Extensor Lag	No significant difference found ( p 0.5). Dorsal splint: 6 degrees. Volar splint: 5 degrees. Custom thermoplastic splint: 7 degrees.	9 cases crossed over treatment groups due to poor compliance or complications. Short follow-up of only 24 weeks for clinical review and 12 weeks for radiographic review.
			Radiographic lag	No significant difference found (p 0.12). Dorsal splint: 16.2 degrees. Volar splint: 13.6 degrees. Custom thermoplastic splint: 9 degrees.
			Michigan Hand Outcome Questionnaire Score	No significant difference found (p 0.78). Dorsal splint: 80. Volar splint: 80. Custom thermoplastic splint: 79.
			Complications	No significant difference found (p 0.95). Dorsal splint: 2 minor, 1 major. Volar splint: 2 minor. Custom thermoplastic splint: 2 minor.
Maitra A, et al. 1993 UK	60 patients with 60 mallet fingers. Adult & paediatric patients, acute injuries only, bony (small fragment) and soft tissue types, no thumbs. Randomised to custom made padded aluminium alloy malleable finger splint (trial splint) or stack splint (control splint). Splints were continued for 6 weeks full-time.	PRCT	Outcome according to Abouna and Brown criteria (1968): Success= extension loss: 0-5°, no stiffness, normal active flexion and extension. Improved = extension loss: 6-150, no stiffness, normal flexion. Failure= extension loss >150 stiffness or impaired flexion.	No significant difference found. Success 37% trial splint vs. 33% stack splint, Improved 20% trial splint vs. 20% stack splint, failure 43% trial splint vs. 47% stack splint.	Randomisation method not stated. Assessors not blinded. Short follow-up time of only 9 weeks. Vague description of time off work and joint stiffness.
			Time off work	No significant difference found. 25% in each group off for 6 weeks.
			DIP and PIP joint stiffness	No significant difference found.
			Complications	Significant difference found (p<0.01). 6.6% trial splint vs. 33% stack splint.
Warren RA , et al. 1988 UK	114 patients with 116 mallet fingers. Adult & paediatric patients, acute injuries only, bony (small fragment) and soft tissue types, no thumbs. Randomised to abouna splint (trial splint) or stack splint (control splint). Splints were continued for 6 weeks full-time.	PRCT	Outcome according to Abouna and Brown	No significant difference found. Success: 39% abouna splint vs. 33% stack cplint, improved 14% abouna splint vs. 19% stack splint, failure 47% abouna splint vs. 48% stack splint.	Quasi randomised based on odd and even hospital numbers. Assessors not blinded. 7% lost to follow-up. Variable follow-up.
			Patients generally satisfied with the splint	Significant difference found. 57% abouna splint vs. 83% stack splint.
Kinninmonth AW, et al. 1986 UK	54 patients with 57 mallet fingers. Age range not known, acute and chronic injuries, bony (size not stated) and soft tissue types, no thumbs. Randomised to custom made perforated splint (trial splint) or stack splint (control splint). Splints were continued for 6 weeks full-time.	PRCT	Lag outcome in patients able to tolerate initial splint: excellent <5 degrees, good <10 degrees	Significance not stated. Excellent/good result in 92% perforated splints vs. 86% stack splint.	Randomisation method not stated. Assessors not blinded. Age range not clear. Mixed acute and chronic.
			Lag outcome including patients who had to change initial treatment	Significance not stated. Excellent/good result in 89% perforated splints vs. 69% stack splint.
			Treatment failure, defined as need to change splint type and/or excessive lag deformity	Significant difference found. 7% perforated splint vs. 33% stack splint.

Comment(s)

There are four PRCT's of varying quality and power in this area. The ideal splint remains controversial. The most recent and best designed study by Pike et al showed no significant difference in outcome between the three different types of splint used. Maitra et al suggest no significant difference in lag outcome between splints but with a significant increase in soft tissue complications in the stack splint group. Warren et al showed no significant difference in lag outcome between splints but with patients being more satisfied with their treatment in the stack splint. Kinnonmonth et al found no significant difference in lag outcome but with a significantly increased number of patients not able to tolerate the stack splint. It is worth noting that the trial splints being examined by Maitra and Kinnonmonth were both custom made.

Clinical Bottom Line

There is currently no gold standard non-operative management. Patients can be adequately managed with a standard stack splint. Where local expertise permits custom made paddded aluminium alloy malleable splints or custom made perforated splints may have advantages in terms of reduced soft tissue complications and increased patient compliance.

References

1. Pike J, Mulpuri K, Metzger M, Ng G, Wells N, Goetz T. Blinded, prospective, randomized clinical trial comparing volar, dorsal, and custom thermoplastic splinting in treatment of acute mallet finger. J Hand Surg Am. 2010 Apr;35(4):580-8. 2010 ; 580-8.
2. Maitra A, Dorani B. The conservative treatment of mallet finger Archives of Emergency Medicine 1993;244–8
3. Warren RA, Norris SH, Ferguson DG. Mallet finger: a trial of two splints. Journal of Hand Surgery - British Volume. 1988; 151–3.
4. Kinninmonth AW, Holburn F. A comparative controlled trial of a new perforated splint and a traditional splint in the treatment of mallet finger. Journal of Hand Surgery - British Volume. 1986; 261-2.