Distal Radial Fractures: the Significance of the Number of Instability Markers in Management and Outcome

Abstract

Introduction

Distal radial fractures are one of the most common orthopaedic injuries. An effective treatment strategy is needed to ensure good outcome and better resource usage.

Aim

To identify the significance of the number of instability markers in distal radial fractures in predicting outcome and proposing a standardized management strategy.

Methods

Data was collected retrospectively over three months at the Northern General Hospital, Sheffield. All patients who had a distal radius fracture in the defined time period and matched our criteria were included. Relevant instability markers identified through a literature review were: age >60 years, dorsal angulation >20°, intra-articular fracture, ulna fracture, dorsal comminution, radial shortening and osteoporosis. The number of instability markers, management and outcome were recorded for each patient. The strategy of management was subdivided into: plaster cast immobilisation with subsequent rehabilitation, manipulation with subsequent cast immobilization and surgery (locked volar plating). Outcomes were graded as “good” or “poor” based on the complications and the function achieved at discharge from follow-up.

Results

Two hundred and seven patients were included in our study. One hundred and nineteen patients had <3 instability markers (Group A) and 88 had >4 (Group B). One hundred and sixty-two were female and 45 were male. The average age was 60 years and the age range was 19 to 96 years. In Group A, 91% achieved “good” outcome regardless of management strategy, versus 66% in Group B (p<0.001). In Group B, amongst patients who had surgery (29), 79% achieved “good” outcome, however those with manipulation alone (38), only 58% achieved “good” outcome (p > 0.03 (one tailed), p > 0.06 (double tailed)).

Conclusions

We have found that four or more instability markers are globally associated with a poorer outcome. Patients with four or more markers who underwent surgery did uniformly better than those with manipulation alone. However, in patients with three or fewer markers, non-operative management yielded equally good outcomes. We plan to use this as a pilot study for future primary research.

Introduction

Distal radial fractures are very common and constitute a significant proportion of the workload for the Orthopaedic department. They are the most common osteoporotic fracture¹ and in a rapidly aging population their incidence is set to rise².

Management of patients with distal radial fractures is controversial, with no clearly adopted management strategy. There is no clear evidence to guide when to adopt non-operative versus operative management and also no definitive evidence to support one surgical fixation method over another. In our practice we had noted patients with higher number of instability markers had better functional outcomes with surgical fixation when compared to non-operative management but had no data to support this.

A significant amount of work is available in literature, which is focused on identifying the instability markers in distal radial fractures. In 1989, Lafontaine et al.³ reported that age > 60 years, dorsal angulation (>20°), dorsal comminution, intra-articular fracture (radio carpal joint surface) and associated ulnar fracture were associated with an increased risk of secondary displacement, despite a correct initial reduction. Similarly, Jenkins⁴ showed that fracture position at presentation was an important indicator of the fracture position at union. Subsequent authors showed similar markers of instability for distal radial fractures^5-8.

While the aforementioned studies identified markers of instability, but there is little published that has investigated the impact of the number of instability markers in distal radial fractures. Therefore the aim of this study was to identify the significance of the number of instability markers in distal radial fractures in predicting outcome and proposing a standardised management strategy.

Patients and Methods

This study was a retrospective case series. Data was collected from the medical records for all patients who presented with a distal radial fracture between January 1, 2008 to January 3, 2009. Exclusion criteria included: Ipsilateral limb injuries, multiple injuries, bilateral wrist fractures, volar angulated fractures, severe systemic illness, open fractures, previous fracture in the same wrist, failed follow up attendance.

A literature review was conducted using the PUBMED database. We reviewed papers that studied radiological and clinical markers of stability for distal radial fractures. The following markers of instability for distal radial fractures were identified: age > 60 years, dorsal angulation >20 degrees, intra-articular fracture, ulna fracture, dorsal comminution, radial shortening of greater than 2 mm and osteoporosis. (Table A).

Table A.

The instability markers for distal radius fracture included in our study

No.	Instability markers
1	age > 60 years
2	dorsal angulation >20 degrees
3	intra-articular fracture
4	ulna fracture
5	dorsal comminution
6	radial shortening of greater than two mm
7	Osteoporosis

We recorded patient demographics, the number and type of instability markers, the management strategy used and patient outcomes. We grouped the management strategies into: plaster cast immobilisation with subsequent rehabilitation, manipulation with subsequent cast immobilization and surgery. In our centre the surgical treatment method employed was locked volar plating using the DVR anatomic locking plates. The standard volar approach was used with the incision centred over the flexor carpi radialis (FCR) tendon. The tendon is retracted and the bed of the muscle is incised and retracted. The pronator quadratus muscle is lifted of the volar surface of the distal radius. The fracture is then identified, reduced and the locking plate applied under the guidance of the image intensifier.

The functional outcome was assessed at discharge from follow-up. This was based on the range of motion (ROM) achieved and the ability to carry out activities of daily living (ADLs). ADLs were subjectively assessed by: recording patient's ability to undertake household work such as shopping, cooking, cleaning, opening a jar and using a knife and fork. The outcome was graded as “good” if patients were satisfied with their ability to undertake ADLs and achieved an acceptable ROM. The outcome was “poor” if after discharge from follow up, patients were still unable to satisfactorily undertake their ADL's.

The radiographic outcome targets were: volar tilt restored (within 10°), radial length within 2 mm, radial inclination within 5°, articular step-off < 2 mm. However if patients failed to achieve these parameters but were still able to achieve good functional outcome, then overall outcome was still deemed as “good”.

A predesigned database was used for collecting the data. The case notes and radiographs for each patient were reviewed. Radial shortening was measured radiologically by drawing two lines perpendicular to the long axis of the radius on an AP view. The first line intersects the tip of the radial styloid and the second line intersects the distal ulnar articular surface. The distance between these two lines is the radial length and any shortening of greater than 2 mm was considered significant. Dorsal angulation was calculated on the lateral film by measuring the angle between a line perpendicular to the long axis of the radius and the distal radius articular surface. Osteoporosis was included if there was a prior diagnosis or a diagnosis made in the notes following the fracture.

The patients were divided into two groups. Group A had < three instability markers and group B had > four. Lafontaine et al.³ in 1989 believed that if there were more than three instability markers then conservative treatment alone would not be sufficient. However, there is no data to support this. We compared the outcomes of conservative management and surgical fixation between these two groups.

Statistical analysis was performed using an exact Chi Square test for proportions. A p-value of <0.05 was considered statistically significant.

Results

In total, 207 patients were included in our study. Of these, 162 were female and 45 were male. The average age was 60 years and the age range was 19 to 96 years. Group A had 119 patients with < three instability markers and group B had 88 patients with > four instability markers (Table B).

Table B.

Comparison of demographics between Group A and Group B

	Group A	Group B
No. of patients	119	88
M: F	94:25	68:20
Average age (years)	63	57
Age range (years)	25-96	19-95

As shown in Table I, amongst the patients with < three instability markers (group A), 82 patients were treated with plaster immobilization and subsequent rehabilitation, without any manipulation or surgery. Out of these 78 patients (95%) had a “good” outcome and four (5%) had a “poor” outcome. Twenty-three patients had either one or multiple manipulations without subsequent surgery, of which 19 (83%) had a “good” outcome and four (17%) had a “poor” outcome. Out of the 14 patients who had surgery, 11 (79%) had a “good” outcome and three (21%) had a “poor” outcome.

Table I.

Patients with ≤ 3 instability markers

Management	No. of patients	Good Outcome	Poor Outcome
Plaster cast immobilization only	82	78(95%)	4(5%)
Manipulation	23	19(83%)	4(17%)
Surgery	14	11(79%)	3(21%)

In Group B (> four instability markers) - (Table II), 18 patients were treated with plaster immobilization and subsequent rehabilitation without any manipulation or surgery. Thirteen of 18 (72%) patients achieved a “good” outcome, whereas five (28%) achieved a “poor” outcome. Thirty-eight patients were treated with one or multiple manipulations without subsequent surgery, of which 22 (58%) had a “good” outcome and 16 (42%) had a “poor” outcome. Amongst the 29 patients who underwent surgery, 23 (79%) achieved a “good” outcome, whereas six patients (21%) had a “poor” outcome. It should be noted that in Group B, the remaining three patients who did satisfy the criteria of having > four instability markers and were therefore initially included in the study had to be excluded as there was no information available on their follow up progress and outcome. Therefore, 85/88 patients in this group are accounted for in table II.

Table II.

Patients with ≥ 4 instability markers

Management	No. of patients	Good Outcome	Poor Outcome
Plaster cast immobilization only	18	13(72%)	5(28%)
Manipulation	38	22(58%)	16(42%)
Surgery	29	23(79%)	6(21%)

We found that in Group A (< three instability markers), 91% achieved a “good” outcome regardless of the management strategy used as compared to 66% in Group B (> four instability markers). (P < 0.001). However amongst patients in Group B (> four instability markers) those who had surgery (29), 79% achieved “good” outcome, whereas those treated with manipulation alone (38), only 58% achieved “good” outcome (one tailed p =0. 03, double tailed p = 0.06).

Discussion

Our study demonstrated that four or more instability markers in distal radial fractures are associated with a poorer outcome. Patients with four or more instability markers did better with surgery when compared to manipulation alone. Those individuals who underwent surgical fixation in Group B were more likely to regain a satisfactory range of motion and be able to return to their pre-injury activities of daily living.

Our findings corroborate with previous studies, demonstrating better results with surgery for unstable distal radial fractures. A study by Koenig et al.⁹ showed that in potentially unstable distal radial fractures treated with locked volar plating the probability of painless union was higher and provided a long term gain in quality adjusted life years which outweighed the risks of surgical treatment in the short term. Figl et al.¹⁰ reported that the treatment of unstable distal radial fractures with a volar fixed- angle plate osteosynthesis in elderly patients showed good anatomical reduction, early return to function and reduced morbidity. Secondary loss of reduction was also prevented by this procedure. Orbay et al. found similar results¹¹, who reported that treatment of unstable distal radial fractures in elderly patients with volar fixed-angle plate provided a more stable fixation and earlier return to function. There is more published data demonstrating good outcome for unstable distal radial fractures treated with locked volar plating^12-17.

The complications of volar locking plates are well documented. Drobetz et al.¹⁸ found flexor pollicis longus tendon rupture as the most common complication. Arora et al.¹⁹ reported that in palmar fixed angle plates, if the screws are too long then they can penetrate the extensor compartments and that distal screws in comminuted fractures can cut through the subchondral bone and penetrate into the radio carpal joint. Knight et al.²⁰ studied 40 patients with volar locking plates, of which 25% had malunion and 12.5% had rupture of the extensor pollicis longus tendon.

In our study the majority of patients in the group with 4 or more instability markers in fact had closed reduction (manipulation) with subsequent plaster immobilisation, without surgery. However, their outcome was not as good as the patients who had surgery within this group (58% v 79% “good” outcome).

A paper which studied the value of closed reduction in 60 distal radial fractures in the very elderly and low-demand demented patients, found that 53/60 (88%) healed in the malunited position²¹. Therefore there is little benefit in manipulating these fractures as the position is rarely maintained. Hence these patients, if they are unfit for surgery, are best treated by plaster immobilisation and follow-up. In our study we found that the majority of the patients in the group with four or more instability markers who were not manipulated or operated upon were low-demand frail and elderly patients and they did reasonably well with plaster cast immobilisation only. A study by Arora et al.²² compared operative versus nonoperative treatment for unstable distal radial fractures in low demand patients 70 years or older. They found that surgery yielded better radiological outcome but there was no significant difference in the functional outcome between the operative and non-operative group. Our results however showed that functional outcome is better in the surgical group as compared to the non-operative group in the patients with four or more instability markers, although in our case this is not limited to the 70 or above age group.

In our study, the vast majority (91%) of patients with < three instability markers had a “good” outcome. There was no significant difference in outcome between the individual management strategies within this group of patients.

This was a pilot study aimed primarily at finding an association between the number of instability markers and management and outcome of distal radial fractures. We understand larger numbers are needed to add weight to the results. Therefore, our future plan is to undertake a prospective, multicenter study with standardised outcome scores such as the DASH (Disability of Arm, Shoulder and Hand) score to reduce the limitations and also to check the reproducibility of the results found in this study.

Conclusions

Four or more instability markers in distal radial fractures are globally associated with a poorer outcome. Patients with four or more instability markers have better outcomes with surgery when compared to manipulation alone. Patients with three or fewer instability markers have a good outcome regardless of the management strategy used. We have shown that looking at the number of instability markers in distal radial fractures is useful in guiding management and predicting outcome.

Conflict of Interest

There are no conflicts of interest amongst any of the authors.