Functional Hand-Based Splint in the Treatment of Metacarpal Fractures

Abstract

Background: Post-treatment stiffness remains a significant hurdle following treatment for displaced or minimally displaced metacarpal fractures. Treatment goals should focus on a stable and acceptable reduction, minimal patient morbidity, and optimal mobility. Methods: A retrospective review of all non-operative metacarpal fractures over a five-month period at a tertiary center hand clinic treated with a hand-based splint were reviewed for radiologic and clinical stability. The splint allowed metacarpophalngeal joint, interphalangeal joint, and radiocarpal joint motion. Data collected included age, handedness, type and location of fracture, occupation, and ability to continue working. Radiologic images were reviewed by a radiologist not otherwise involved in patient care. Results: Thirty-three patients were reviewed with a total of 39 fractures of the second, third, fourth, and fifth metacarpals. Nine patients had nondominant hand fractures while 24 were dominant hand injuries. Twenty out of 24 patients employed pre-injury were able to continue working without missing any days. Three patients were lost to the final follow-up. The average splint duration was 24 days. Twenty-seven of 30 patients showed no change in alignment from start of splinting to end, while three showed some change but remained within non-operative criteria. Conclusion: A hand-based functional splint for metacarpal fractures allows for excellent maintenance of fracture reduction, early or immediate return to pre-injury activities, low patient morbidity, and maintains functional motion throughout treatment. It can be applied to any non-operative fracture of the second through the fifth metacarpal.

Introduction

The current management of metacarpal fractures is not uniform.^1-7 There is considerable variability in the criteria for surgery,^4,8-10 as well as the type of non-operative treatment made available for these injures.^5,10-13

Metacarpal and phalangeal fractures account for 10% of all fractures, many in athletes or people of working age. ¹⁴ It is generally agreed that the best treatment is one that provides a stable and acceptable reduction, minimal soft tissue injury, and early return of motion allowing return to work or play.^3,13,14

Among specialties in the United States providing care for metacarpal fractures, there is a significant difference in management as orthopedic surgeons are found to be less likely than plastic surgeons to perform surgery versus closed reduction and splinting. ⁷ In Canada, there is general agreement by plastic surgeons on operative criteria as demonstrated by Retrouvey et al though there is much greater variability when it comes to no-operative management. ⁴ They list unstable fractures, open fractures, malrotation, and angulation out of line with normal joint movement as primary criteria for operative management.

Recent studies have suggested that boxers’ fractures (fifth metacarpal neck fractures) are being over-treated by casting and immobilization and that similar results can be obtained by buddy taping alone. A study from the United Kingdom suggests that no treatment at all for boxers’ fractures with less than 50 degrees of angulation is acceptable with similar functional outcomes. ⁹

Significant attention has been paid to the athlete population when it comes to metacarpal fractures as this group tends to have a higher demand for early return to play.^14-17 It is recognized that this group often has minimally displaced injuries and often benefits from immobilization and early range of motion (ROM) versus surgery. ¹⁵ Long-term outcomes are equal in conservative versus operative management for minimally displaced fractures, ¹⁶ and cases undergoing surgery have a longer return to play than those not operated upon. ¹⁷ This longer return to play is affected by the delay in waiting for surgery. Splinting alone for minimally displaced metacarpal fractures was shown to have an average return to play in the athlete population of 22 days. ¹⁷

When determining which joints to immobilize, the standard rule for fractures is “the joint above and below” but this rule is often broken. Distal radius fractures and ankle fractures being classic examples where the elbow and knee respectively are not immobilized. The general purpose of cast immobilization is to allow minimal motion through the healing bone. ¹ This can be achieved directly by preventing movement, or indirectly by limiting the motion of destabilizing muscle forces.

Some splints, such as those use for some boxers’ fractures allow movement of the interphalangeal joints while immobilizing the metacarpophalangeal joint. However, a standard volar slab or gutter splint in the position of safety requires immobilization of the three joints below the metacarpal fracture and three above. There are few destabilizing muscle forces on the metacarpal itself.^1-3 Forearm muscle insertions onto the metacarpals are at the base of the metacarpal and are balanced between flexor and extensor forces unless a fracture disrupts the bony interface between these forces. Dorsal interosseous muscles originate from adjoining metacarpals and therefore have a balancing counter force from each side. In addition, the deep transverse metacarpal ligaments interconnect the heads of the second through fifth metacarpals, reducing movement of the distal bone.

As a result of this information, we changed our splint technique from a gutter splint or volar slab to a hand-based thermoplastic splint leaving the radiocarpal joint free and the metacarpophalangeal joint free. This study was performed as a retrospective review of our results on 33 consecutive patients to determine the success of this treatment option: Would it successfully stabilize the fracture, allow continued work or play, minimize post splinting stiffness, and reduce patient morbidity?

Methods

A retrospective review was conducted. All patients presenting to a single surgeon's tertiary center hand clinic for evaluation of metacarpal fractures over a five-month period were considered for the review. All patients with metacarpal fractures not requiring surgery were included. Any patients requiring surgery were excluded as well as any requiring management of other injuries (eg, tendon injuries, wrist injury, or phalangeal fracture). Operative criteria are listed in Figure 1.

Figure 1.

Operative Criteria.

Any necessary reductions were performed before the splints were applied. All patients were then made a thermoplastic hand-based splint by a staff hand therapist (Figure 2a–c). All splints allowed motion at the wrist joint as well as the metacarpophalangeal joint and interphalangeal joint joints. The splint is waterproof. Patients were instructed to leave the splint on except after showering, at which time the splint could be removed briefly to allow for drying.

Figure 2.

The functional hand based splint with the hand at rest and in action.

Patients were told to use their hands as normally as possible, though due to possible legal issues were advised, as with any splint, to avoid driving or operating heavy machinery.

Patients were seen at weekly intervals for clinical and radiologic examination until clinical signs of bone healing were achieved. These signs were: non-tender to palpation, lack of crepitus/mobility at the fracture, and stress grip without pain. At this point, all patients had their ROM tested by the surgeon. Any patients not able to either extend all metacarpophalangeal joints and interphalangeal joints to zero degrees or flex to a tip to palm distance of zero were sent for a consultation with a hand therapist for a range of motion exercises.

Radiological studies were then independently studied by a radiologist (FH) who had until that time not been involved in the study and was not informed as to the reason to review the images in order to provide a blinded opinion. The radiologist compared images from the start of splinting to the final series to determine any change in fracture reduction.

Results

The results are listed in Tables 1 and 2. The review period included 11 female and 22 male patients for a total of 33 patients. The age range was 13–84 with an average age of 43.5. Seven patients had multiple metacarpal fractures while 26 were single bone injuries. In total there were 20 midshaft fractures, 13 base fractures, and six neck fractures. Four patients were left-hand dominant, two were ambidextrous, and the rest (27) were right-hand dominant. Nine patients had nondominant hand injuries while 24 had dominant hand injuries.

Table 1.

Patient Demographics.

Pt	Dominant	Occupation	M/F	Age	Fracture	Continue to work	Days splinted
1	Right	Painter	M	23	R 3MC base	Yes	24
2	Right	Unemployed	F	57	R 5MC base	Unemployed	24
3	Right	Unemployed	M	24	R 5MC neck	Unemployed	38
4	Right	Framer	M	28	R 5MC mid	No	21
5	Right	Homemaker	F	40	L 5MC mid	Yes	28
6	Right	Clerk	F	60	L 4,5MC mid	Yes	31
7	Right	Retired	F	81	R 4,5MC base	Retired	35
8	Right	Pest control	M	59	R5MC mid	Yes	28
9	Right	Framer	M	23	R3MC mid	Incarcerated	35
10	Right	Retired	M	80	R 5MC mid	Retired	20
11	Right	Landscaper	M	22	R 5MC neck	Yes	Lost to F/U
12	Ambi	Student	M	13	R 5MC base	Yes	14
13	Right	Electrician	M	31	R 5MC mid	No	35
14	Right	Student	M	17	R 4MC mid	yes	22
15	Right	Retired	F	80	L 5MC base	Retired	Lost to F/U
16	Right	Student	M	24	R 5MC neck	Yes	24
17	Right	Programmer	M	36	R 3,4MC mid	Yes	28
18	Right	Unemployed	M	38	L 5MC base	Unemployed	14
19	Left	Student	F	22	L 5MC mid	Yes	18
20	Right	Sales	M	37	R 5MC neck	Yes	21
21	Right	Cook	M	31	L 2MC mid	Yes	24
22	Left	Unemployed	M	29	L4MC base, 5MC mid	Unemployed	Lost to F/U
23	Right	Hygienist	F	50	L 5MC mid	Yes	21
24	Right	Marketing	F	34	R 5MC base	Yes	18
25	Left	Clerk	M	52	R 4,5 MC base	No	28
26	Right	Unemployed	M	24	R 2 MC mid	Unemployed	22
27	Right	Student	M	17	L 4,5 MC mid	Yes	19
28	Right	Retired	M	84	R 5 MC mid	Retired	21
29	Right	MOA	F	60	R 5MC base	Yes	24
30	Left	Dietician	F	44	R 4MC mid	Yes	18
31	Right	Student	M	21	R 5MC neck	Yes	18
32	Ambi	Ski instructor	M	61	R4,5 MC mid	No	24
33	Right	Lawyer	F	45	R 5 MC mid	Yes	21

Abbreviation: F/U = Follow-up.

Table 2.

Pre- and Post-treatment Radiologic Evaluation.

Pt	Dom	M/F	Age	Fracture	Fracture pattern	Pre-splint reduction	Pre-splint angle	Post-splint angle
1	RHD	M	23	R 3MC base	Ob, U	No	Neutral	Unchanged
2	RHD	F	57	R 5MC base	Ob, U, IA	No	Neutral	Unchanged
3	RHD	M	24	R 5MC neck	Tr	Yes	20 Degrees apex dorsal angulation	45 Degrees apex dorsal angulation
4	RHD	M	28	R 5MC mid	Tr	Yes	Neutral	Unchanged
5	RHD	F	40	L 5MC mid	Sp	No	Neutral	Unchanged
6	RHD	F	60	L 5MC mid	Sp	No	Fifth MC <1 mm ulnar displaced, fourth MC neutral	Both unchanged
				L 4MC mid	Ob	No
7	RHD	F	81	R 4MC base	Tr	No	Fourth MC neutral, fifth MC ulnar displaced 2 mm	Both unchanged
				R 5MC base	Tr	No
8	RHD	M	59	R5MC mid	Sp	Yes	Neutral	Unchanged
9	RHD	M	23	R3MC mid	Tr	No	Neutral	Unchanged
10	RHD	M	80	R 5MC mid	Ob	Yes	Neutral	Unchanged
11	RHD	M	22	R 5MC neck	Ob	No	Neutral	Lost to follow-up
12	AMBI	M	13	R 5MC base	Tr	No	Neutral	Unchanged
13	RHD	M	31	R 5MC mid	Tr	Yes	18 Degrees apex dorsal angulation	Unchanged
14	RHD	M	17	R3 MC mid	Sp	No	Third MC neutral, fourth 1 mm ulnar displaced	Both unchanged
				R 4MC mid	Sp	No
15	RHD	F	80	L 5MC base	Ob, U, IA	No	Neutral	Lost to follow-up
16	RHD	M	24	R 5MC neck	Ob	Yes	Neutral	Unchanged
17	RHD	M	36	R 3,4MC mid	Ob	No	Neutral	Unchanged
18	RHD	M	38	L 5MC base	Ob	Yes	5 Degrees apex dorsal angulation	8 Degrees apex dorsal angulation
19	LHD	F	22	L 5 MC mid	Ob	Yes	5 Degrees apex dorsal angulation	Unchanged
20	RHD	M	37	R 5MC neck	Tr	Yes	10 Degrees apex dorsal angulation	Unchanged
21	RHD	M	31	L 2MC mid	Ob	No	Neutral	Unchanged
22	LHD	M	29	L 4MC base	Ob	No	4MC Neutral 5MC 1 mm radial displaced	Lost to follow-up
				5MC mid	Ob
23	RHD	F	50	L 5MC mid	Sp	No	Neutral	Unchanged
24	RHD	F	34	R 5MC base	Ob	Yes	Neutral	Unchanged
25	LHD	M	52	R 4MC base R 5MC base	Ob Sp	No	4MC Neutral, 5MC ulnar deviated 2 mm	Both unchanged
26	RHD	M	24	R 2 MC mid	Ob	Yes	5 Degrees apex dorsal angulation	Unchanged
27	RHD	M	17	L 4MC mid	Ob	No	4MC Neutral, 5 MC 10 degrees apex dorsal angulation	Both unchanged
				L 3 MC mid	Ob
28	RHD	M	84	R 5 MC neck	Tr	No	10 Degrees apex dorsal angulation	14 Degrees apex dorsal angulation
29	RHD	F	60	R 5MC base	Tr	No	Neutral	Unchanged
30	LHD	F	44	R 4MC mid	Sp	No	1 mm shortening	Unchanged
31	RHD	M	21	R 5MC neck	Tr	Yes	20 Degrees apex dorsal angulation	Unchanged
32	AMBI	M	61	R 4MC mid	Ob	No	4MC Neutral, 5MC 2 mm ulnar deviated	Unchanged
				R 5MC base	Tr
33	RHD	F	45	R 5 MC mid	Ob	Yes	15 Degrees apex dorsal angulation	Unchanged

Abbreviations: Tr, Transverse; Sp, Spiral; Ob, Oblique; IA, Intraarticular; U, undisplaced; LHD, Left Hand Dominant; RHD, Right Hand Dominant; MC, Metacarpal; MOA, Medical Office Assistant.

Of those employed or students at the time of injury, 20 out of 24 did not miss any school or work time while splinted.

All patients were seen within three days of injury. Twelve fractures required reduction at the clinic or the emergency department. Twenty-seven of the 39 fractures showed no angulation or had displacement less than 2 mm prior to splinting.

Thirty of 33 patients continued to receive care until their splint was removed in the clinic accounting for 35 of the 39 fractures, while three were lost to follow-up. The average duration of splinting was 24 days (23.9, Range 14–38). Twenty-seven of the 30 series of radiologic images did not show any change in alignment or angulation between first images and final images. Two series showed less than five degrees change while one patient suffered a second injury while splinted when they fell skateboarding resulting in a 20-degree change of angulation. In each of these cases, the resulting change in angulation was not sufficient to reach operative criteria.

All of the patients at the time of discharge had a functional range of motion and none required hand therapy.

Discussion

The end goals in any treatment for metacarpal fractures are a stable and satisfactory reduction with maximum function and minimal morbidity. Despite this, the most common complication following the acute management of metacarpal fractures is stiffness.^18,19 Therefore, hand surgeons should be trying to reduce the extent and duration of immobilization so as to prevent soft tissue tightening while maintaining bony reduction.

While open reduction and internal fixation (ORIF) has been shown to allow an earlier range of motion than other treatment modalities for unstable fractures,^13,16 in the case of stable fractures in an acceptable position, the tissue trauma and infection rate connected to ORIF is a significant risk that must be considered. The goal of non-operative treatment therefore is to prevent a fracture from shifting into a non-acceptable position, reduce patient discomfort and maximize long-term function with a minimal recovery period.^1,3,13 The ongoing use of the hand in pre-fracture activities while being treated should also be considered.

The easiest way to achieve an early range of motion is to minimize the period of time and the number of joints immobilized. ¹⁵ Despite this, many hand surgeons still rely on plaster splinting including the forearm and interphalangeal joints for the management of metacarpal fractures.^4,5,7

In athlete-related metacarpal injuries, there is a focus on a quick return to sport.^14,15 Fractures treated with splinting and early ROM all returned to pre-fracture activity within an average of twenty-two days ¹⁷ and were shown to have equivalent total active motion versus surgically managed fractures in long-term follow-up. ¹⁶ Interestingly, surgically managed injuries in athletes had a longer return to play (29 days vs 22 days) in Geoghegan et al's study. ¹⁷ The time in getting patients to the operating room was a factor in this delay.

Recent papers have looked at the management of boxers’ Fractures in an attempt to reduce treatment morbidity and stiffness.^5,10-12 They have shown equivalent fracture position maintenance using buddy taping versus splinting, with reduced workdays lost and better early range of motion. ¹⁰

Taking it a step further, a group in the United Kingdom has gone so far as to not treat any boxers’ Fractures with less than 50 degrees of angulation and they reported no time missed for work and high satisfaction on follow-up. ⁹

These studies have pointed treatment in the direction of reduced splinting and more motion early on for boxers’ fractures, where the deforming forces on the bone have usually reached a maximum position at the time of initial contact with a hand surgeon. Further immobilization to prevent passive fracture movement is unlikely to add anything to this healing. Patients have to be willing to accept the potential loss of knuckle prominence and metacarpophalangeal joint hyperextension associated with this non-reduced position. ¹¹ However, many hand surgeons still attempt reduction^5,7 for boxers’ fractures and as these fractures have been reduced, splinting might be appropriate to try to prevent the loss of reduction.

When considering a management technique for hand fractures, specific goals should be addressed. An ideal treatment protocol should achieve three goals: (1) equivalent or better fracture healing versus standard therapy, (2) improved immediate post-treatment mobility, and (3) reduced treatment morbidity or improved patient satisfaction.

The splint we use allows for 70-degree flexion/70-degree extension of the wrist, 90-degree flexion and full extension of the metacarpophalangeal (MCP) joints and full motion of the interphalangeal joints (Figure 2c and d). With this splint, the carpometacarpal (CMC) joints are stabilized and do not allow flexion of the fourth and fifth CMC joints (Figure 2a–c). Our results showed complete maintenance of reduction in 27 of 30 patients representing 35 of 39 fractures, while two fractures slipped less than five degrees in angulation, suggesting that these fractures were adequately protected during the treatment period.

This splint is able to allow fracture healing, despite mobility of the MCP joint, by various possible mechanisms. By preventing flexion of the fourth and fifth CMC joints, the splint might help in preventing rotational torque on a fracture of these two metacarpals. In addition, the prevention of CMC joint movement can prevent excess volar/dorsal forces on metacarpals two through five. The splint also serves as a reminder of injury versus no splint which will reduce the patient from trying to do too much and jeopardize their healing fracture. Finally, it provides some protection from direct force against the fracture site, though in the one patient who fell skateboarding it was insufficient to prevent some further apex dorsal angulation.

Most employed patients in our study were able to return to work immediately, as the splint allows nearly full motion of the digits and a functional level of grip (Figures 6e–g). This suggests that there is adequate pain management with this splint, though this needs to be more formally tested. The splint being waterproof facilitates use in most environments. In addition, as the splint material is only 1.5 mm thick, there is little bulk added to the hand, further improving grip versus bulkier fiberglass splints with padding. All students were able to continue school attendance without missing any days. Pencil grip is maintained with this splint which allowed students to continue to write when needed. Typing movements were not inhibited, when tested by the hand therapist and surgeon who had their own splints made.

In this series of patients, the splint was used on fractures involving fractures of the second, third, fourth, and fifth metacarpals involving the base, midshaft, and neck. Fractures included transverse, oblique, and spiral patterns. All fractures were successfully treated in this study. The limitations in this review are first and foremost that it was a small sample size. However, given the success of this splint, we believe the short study period shows this to be a good option for the treatment of these fractures. The next step will be to increase the number of treated patients reviewed to try to identify potential exclusion criteria for this splint technique. However, the high success rate within this review shows that it is a valid option going forward, provided close follow-up is performed until further data is available. To ensure adequate reduction maintenance, we brought the patient back weekly for review, though will revert follow-up imaging to our institutional standard of one week and three weeks for these patients.

We believe that this splint technique allows for excellent maintenance of fracture reduction, low patient morbidity and maintains functional motion throughout treatment. It can be applied to any non-operative fracture of the second through the fifth metacarpal.

Author’s Notes

The paper follows all ethical guidelines for the Fraser Health Authority. All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008. Informed consent was obtained from all patients for being included in the study.