Audit changes practice-a simple education intervention can lead to better outcome in ankle fracture surgery

Abstract

Background

Unstable ankle fractures are common, and majority requires open reduction and internal fixation (ORIF). There is emerging evidence that the rate of malreduction has remained high despite advances in surgical techniques and implants. Malreduced ankle is a prominent cause of post-traumatic ankle arthritis leading to poor patient reported outcome. The aim of this study was to investigate the quality of anatomical reduction and surgical fixation of ankle fractures and the impact of simple education intervention on the quality of reduction of these fractures.

Methodology

An audit cycle was completed in two phases; retrospective review (phase 1) of 114 cases operated prior to an education intervention using infographic posters and then a prospective (phase 2) review of 96 consecutive cases operated after the education intervention. Data including age, fracture morphology, time to surgery, and the quality of reduction were assessed. The quality of anatomical reduction was evaluated using radiological parameters described by Pettrone. Paediatric, Weber A, pathological and open fractures were excluded. Education interventions included regional teaching and dissemination of infographic posters. Mann- Whitney U test and Chi-squared test were used to compare continuous and categorical data between phase 1 and 2 respectively. P value < 0.05 was considered significant.

Results

Phase one cohort showed malreduced fixation in 25% of cases. Inadequate restoration of fibular length was the most common type of malreduction. After implementation of education intervention, malreduction rate reduced to 9.4% in phase 2 (p = 0.015). There were no significant differences between age, gender, and time to surgery between phase one and two.

Conclusion

This study demonstrates that simple education intervention can lead to better understanding of fixation and decrease the rate of malreduction of these fractures. We recommend that using Pettrone’s radiological criteria in correction of corresponding anatomy of ankle fracture is a useful tool to avoid malreduction.

1. Introduction

Ankle fractures, varying in severity and pattern, are among the most common injuries requiring surgical treatment.^1,2 Malreduction following ankle fracture surgery has been reported as a common predisposing factor leading to post-traumatic arthritis.³ A lateral displacement of the talus by only 1 mm leads to 42% reduction in the area of tibiotalar contact, increasing the stress on the articular cartilage.¹⁴ Therefore, restoration of length with correction of the axis and rotational deformity of the fibula, and ankle mortise is an absolute priority.¹² A systematic review of literature¹¹ showed that poor fracture reduction resulted in an inferior long-term outcome compared to absolute anatomic reduction. Failure to achieve an adequate fracture reduction may lead to an irreversible osteoarthritis and poor functional outcomes necessitating revision surgery.8, 16, 25 Current literature reported high risk of malreduction in ankle fractures undergoing internal fixation, and of these majority required revision surgery.²⁴

For several reasons, adequate anatomic reduction may not be achieved. Despite the extreme sub-specialisation in orthopaedic surgery, the frequency of ankle fractures in daily practice leads to several types of professionals participating in its management, including trainees or non-foot and ankle specialists. Considering this, combined with other factors including surgeon’s experience, understanding of common pitfalls and learning curve in some groups, may influence the outcome. Furthermore, the first ‘Getting it Right First Time’ (GIRFT) report recommended changes to National Health Service orthopaedic practice in UK to improve patient outcomes and achieve cost reductions.²⁰

Ample literature exists reporting on the importance of adequate anatomic reduction on the outcome, however there is no clear consensus on what criteria to use in order to define adequate anatomic reduction,⁹ and thereby minimise common surgery-related complications. Pettrone et al., described quantitative criteria for prediction of functional outcome after fixation of a displaced fracture of the ankle.⁴ They reported high interobserver agreement for the assessment of the quality of ankle fracture reduction which correlates with functional outcome.⁴

The primary aim of this study was to evaluate the quality of anatomical reduction and internal fixation and identify the most common radiological errors based on Pettrone’s⁴ and Weber’s⁵ criteria. The secondary objective was to investigate whether an education intervention and dissemination of infographics could improve the quality of fracture reduction.

2. Methods

2.1. Study population and design

We conducted an audit cycle reviewing the quality of operative ankle fracture reduction in adults aged 18 and older treated at a trauma unit in two separate phases.

2.1.1. Phase one

A retrospective review was already completed evaluating the quality of operative fracture reduction following internal fixation of ankle fractures using Pattrone’s and Weber’s criteria in 114 consecutive cases, between October 2006 and December 2007. The collected data in phase one was presented in the departmental clinical governance meeting and subsequently circulated to local audit department. Results were delivered in form of infographic posters (see Picture 1.) and further informative training sessions were arranged about 3 months prior to second phase to promote adherence to a set guideline to assess achieving adequate anatomic fracture reduction intra-operatively.

Picture 1.

Infographic poster describing the result of phase 1 audit and 3 steps (top tips) to guide adequate anatomical reduction.

2.1.2. Phase two

A prospective review of 96 further consecutive cases was undertaken between November 2015 and April 2017 to assess the quality of fracture reduction and the impact of education intervention. The operating surgeons were unaware of phase two audit. The outcome measures were similar as in phase one.

2.2. Data management and selection criteria

Data collected included patient demographics, fracture morphology and time to surgery. Paediatric ankle fractures, polytrauma, lateral malleolus Weber type A fractures, posterior malleolar fractures requiring surgical fixation, open fractures and dislocations, pre-existing arthritis or joint incongruity, pathological fractures, and pilon fractures were excluded. The fractures were classified using the Weber’s classification system.¹⁵ Radiological data was retrieved from theatre log and PACS (picture archiving and communication system). Radiographs were reviewed by two independent assessors (AK, VR) who were not involved in the surgical procedures.

2.3. Description of surgical techniques (primary ORIF)

Fibular fixation consisted of an anatomic reduction using lag screws and a neutralization plate (one third tubular) for spiral/oblique fracture patterns or bridge–plate fixation for comminuted fracture patterns. Medial malleolar fixation (if fractured) consisted of 2 parallel cancellous lag screws for external rotation injury patterns or lag screws with a small fragment anti-glide plate for vertical shear injury patterns. In a few cases, potentially due to the size of fragment, 1.6 mm Kirschner-wires with tension band wire principle were used. Deltoid ligament repair (equivalent fractures) was not performed routinely. Based on individual surgeon preference, the syndesmosis was fixed using one or two 3.5 mm fully-threaded-cortical- screw, capturing either 3 or 4 cortices of purchase.

2.4. Outcome measurement

The primary outcome of interest was to investigate the quality of operative fracture reduction using part of the radiological parameters described by Pettrone (see Picture 1.).⁴ Radiographs (pre, intra and post-operative) of all included cases in both phases were analysed independently by three assessors to evaluate the quality of fracture reduction; discrepancies were resolved by consensus.

This analysis essentially comprised of an assessment of the ankle joint congruency using the radiological parameters derived from Pettrone’s criteria, which state that an anatomically reduced ankle joint must have:

• 1.Restoration of correct fibular length as assessed by a smooth circle (O- sign or Weber’s dime test) drawn between the lateral recess of talus and distal fibula flare.⁵ This represents that the lateral malleolus fits into the fibular notch.
• 2.Tibiofibular clear space of less than 5 mm (the distance between the medial border of the fibula and the floor of the tibiofibular incisura), measured 10 mm above the ankle joint level on the antero-posterior view (plain radiograph).
• 3.Medial clear space of less than 4 mm (measured on mortise-view).

2.5. Statistics

Differences in non-normally distributed continuous data were determined using the Mann- Whitney U test. Associations in categorical data were determined using a Chi-squared test or Fisher’s exact test depending on the number of cases compared. Significance was assessed at 5% level of significance. SPSS version 22.0 statistical software (SPSS Inc, Chicago, Illinois) was used for data analysis.

3. Results

Of the 114 ankle fractures included in phase 1 audit, there were 60 females and 54 males with a mean age of 48 years at the time of primary operation (range, 18–91). There were 68 Weber B and 46 Weber C fractures (Table 1). The medial malleolus was fractured in 63% of cases, and a small posterior malleolar fragment, not indicated for surgical fixation, was found in 24% of cases. Syndesmosis was disrupted in 31% of cases. Mean time to surgery was 5.7 days (range, 0–23). Sixteen cases (14%) had their surgery within the first 24 h of injury, 35 cases underwent fixation within 72 h, and the remainders (n = 63) had surgery later than 72 h of their injury.

Table 1.

Patient demographic, fracture morphology and time to primary surgery.

	PHASE I (N = 114)	PHASE II (N = 96)	P VALUE
MEAN AGE (RANGE)	47 (18–91)	39 (18–86)	0.621a
FEMALE	60	37	0.213a
MALE	54	59	0.265a
FRACTURE MORPHOLOGY
A. WEBER B	68	62	0.722b
B. WEBER C	46	34	0.627b
MEDIAL MALLEOLUS	72	47	0.274b
POSTERIOR MALLEOLUS	27	23	0.971b
SYNDESMOTIC WIDENING	35	24	0.492b
MEAN TIME TO OPERATION (RANGE)	5.7 days (0- 23)	2.1 days (0- 18)	0.016a
- <24 HRS	16	37	0.002
- 24–72 HRS	35	26	0.670
- >72 HRS	63	33	0.062

^aMann-Whitney U test.

^bChi² test.

Malreduction was observed in 25% of cases (n = 28). Of these, 43% (n = 12) had increased medial clear space or malreduced syndesmosis, and 39% (n = 11) of cases were fixed with inadequate restoration of fibular length (see Table 2). The remainders (n = 5) had a combination of malreduced lateral and medial malleoli. The most common single malreduction was related to the inadequate restoration of the fibular length.

Table 2.

Demonstrates characteristics of malreduced fixation compared between phase I & II.

	PHASE I (N = 114)	PHASE II (N = 96)	P VALUE
OVERALL NO. OF MALEREDUCTION (%)	29 (25.4%)	11 (9.4%)	0.015
A. MALEREDUCED FIBULA LENGTH	11 (9.6%)	4 (4.2%)	0.121
B. MALREDUCED MEDIAL MALLEOLUS ± SYNDESMOSIS	12 (10.5%	3 (3.1%)	0.059
C. MALREDUCED LATERAL AND MEDIAL MALLEOLUS	5 (4.4%)	4 (4.2%)	1.

In phase two, 96 ankle fractures were operated at a mean age of 39 years (range, 18–86). There were 59 males and 37 females (see Table 1). The pre-operative radiographs were not available for evaluation in two patients. Using Weber’s classification, 62 had Weber B and 34 of cases with Weber C fractures (Table 1). Forty-seven (48.9%) ankles had associated medial malleolus fractures, and small posterior malleolar fragment (involving less than 20% of joint surface) was seen in 23 (23.9%) of these. Syndesmosis was disrupted in 24 of cases (25%). Mean time to surgery was 2.1 days (range, 0–18). Almost 40% of cases underwent surgical intervention within 24 h of the initial injury, a significant difference from phase 1, (p = 0.002). Malreduction was noted in 9.4% (n = 11) of cases which was significantly reduced in comparison to phase 1 (p = 0.015). Four ankles had inadequate restoration of the fibular length, 3 had malreduced medial malleolus fractures (two of these were fixed using one screw and one k-wire). The remainders (n = 2) demonstrated a combination of malreduced syndesmotic and fibular length. There was no significant difference in age and gender between the two phases. The overall time to surgery was significantly shorter in phase 2 in comparison to phase 1 (p = 0.015).

4. Discussion

There is limited published literature investigating rate of and the factors affecting malreduction in ankle fracture surgery. Malreduced ankle predisposes to significant morbidity and poor function.^9,16 To our knowledge, the present study is the first to focus on the impact of educational intervention on improvement of ankle fracture reduction.

Our results show that the majority of malreduced ankles are due to malreduced fibular fractures followed by medial malleolus fractures. We also found that the most common combination was malreduced fibular length and increased medial clear space. Ankle malerductions have been shown to have significant impact on maximum recovery and best functional outcomes.^7,17 Additionally, a malreduced fibula^13,18 and joint incongruence lead to pathological load distribution and accelerated secondary degenerative changes⁶ resulting in poor functional outcome.¹⁰ It is known that malunion of the fibula is the most common and the most difficult malunion to reconstruct.¹⁹ Therefore, particular attention must be paid to fibular length and rotation assessment in the operative treatment of this common fracture, especially in patients with more complex fracture patterns.

Our results from phase one suggest a significant rate of malreduction following primary surgical fixation. We achieved a significant improvement in the rate of malreduction in ankle fracture surgery following an educational intervention and dissemination of poster infographics describing three parameters from Pettrone’s criteria for radiological assessment of anatomic reduction of the ankle fractures during surgical fixation. Despite this good result, there were cases of malreduction in phase 2 in more complex cases, particularly trimalleolar ankle fractures with syndesmotic disruption. Since more complex fractures, such as trimalleolar fractures and fracture dislocations, are more prone to postoperative malreduction, the treatment of these injuries should probably be left to experienced trauma surgeons or sepcialist foot and ankle surgeons. In our cohort, the majority of these fractures were fixed by non foot and ankle specialist surgeons..

Recent studies have demonstrated the impact and efficacy of education intervention or the dissemination of the research findings in a format of information graphics (infographics) or poster which helps to maximize communication and exposure to important factors in an engaging and accessible way.²³ Inforgraphics offer value to trainees or trainers in summarizing clinical guidelines, as a tool for education or just a reminder. Information graphics in form of posters facilitate long term retention of information compared with reading text alone.21, 22, 23 We observed significant improvement in the quality of ankle fracture reduction intra-operatively following an education intervention including dissemination of infographic posters illustrating results of phase one audit and three radiological parameters (Pettrone’s criteria) in assessment of adequate fracture reduction (as a guidance ‘get it right first time’).²⁰

This study had some limitations. We only assessed the quality of reduction based on plain radiographs and two orthogonal views. Postoperative CT-scans are not routinely obtained in our institution following ankle fracture surgery, and therefore CT-scans were not available for all post-surgical patients. Hence, we acknowledge that we may have missed some syndesmotic malreductions. In addition, the level or grade of operating surgeon and smaller sample size in phase II study could have introduced bias to the results. Another limitation of this study is that we did not seek to correlate our findings with functional outcomes. However, a previous publication from ours and another unit has shown that in a previous patient reported outcome in patients whose fractures were malreduced at time of primary surgery.²⁵

The present study identified the most common technical errors related to ankle fracture surgery. Restoration of the fibular length and syndesmosis are key elements in achieving a congruent ankle joint. Our findings reveal that most of these errors could be successfully corrected in the acute setting if the operating surgeon is aware of a methodical approach to assess intra-operative radiographs. Recognising these pitfalls in the operative treatment of these common injuries is essential. However, the main message of this audit study is to emphasise the need for regular service evaluation and effective education intervention to improve quality of practice and patient care.