Minimally invasive reduction and percutaneous

Minimally invasive reduction and percutaneous fixation versus open reduction and internal fixation for displaced

intra-‐articular

calcaneal

fractures;

a

systematic review of the literature Author: Mr. Haroon Majeed, MBBS, MRCS Qualification Submitted For: Masters in Trauma & Orthopaedics Institution: University of Salford Year of Submission: 2015 This dissertation is submitted in partial fulfilment of requirement for the degree of MSc Trauma and Orthopaedics, University of Salford, May 2015.

Word Count: 12,806 1

DECLARATION The author declares that no part of this dissertation has been taken from existing published or unpublished material without due acknowledgement and that all the secondary material used herein has been fully referenced. No funding has been received from any source during the completion of this dissertation. Signed……………… Date………………….

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CONTENTS Acknowledgements ………………………………………………………………………………… 5 Abbreviations ………………………………………………………………………………… 6 Abstract ………………………………………………………………………………… 7 Keywords ………………………………………………………………………………… 9 1. Introduction ………………………………………………………………………………… 10 1.1 Incidence ………………………………………………………………………………… 10 1.2 Displaced Intra-‐articular Calcaneal Fractures.……………………………. 10 1.3 Clinical Presentation…………………………………………………………………. 10 1.4 Classification…………………………………………………………………………….. 11 1.5 Radiological Assessment…………………………………………………………… 12 1.6 Management……………………………………………………………………………... 13 1.6.1 Open Reduction and Internal Fixation…………………………............................. 14

1.6.2 Minimally Invasive reduction and percutaneous Fixation…………………. 15

1.7 Why Are Calcaneal Fractures Important?.................................................... 16 1.8 What Is Already Known and What Is Unknown?...................................... 17 2. Methodology …………………………………………………………………………………. 19 2.1 Research Aim……………………………………………………………………………. 19 2.2 Research Objectives…………………………………………………………………... 19 2.3 Literature Search………………………………………………………………………. 19 2.3.1 Inclusion Criteria…………….…...…………………………………………………………. 19

2.3.1.1 Patient Population…………………………………………………………... 2.3.1.2 Intervention……………………………………………………………………. 2.3.1.3 Outcomes………………………………………………………………………... 2.3.2 Exclusion Criteria…………………………………………………………………………… 2.3.2.1 Patient Population…………………………………………………………... 2.3.2.1 Intervention……………………………………………………………………. 2.3.3 Electronic Database Search……………………………………………………………... 2.3.4 Search Strategy………………………………………………………………………………. 2.3.4.1 MeSH Terms…………………………………………………………………… 2.3.4.2 Keywords……………………………………………………………………….. 2.3.5 Types of Studies……………………………………………………………………………... 2.3.6 Data Extraction…..…………………………………………………………………………... 2.3.7 Appraisal of Quality Assessment………………………………………………………

19 20 20 20 20 21 21 21 21 22 22 22 23

3.2.2 Ethical Standards………………………………………………………………………….... 3.2.3 Inclusion and Exclusion Criteria…………………………………………………….... 3.2.4 Patient Population and Intervention………………………………………………... 3.2.5 Fracture Diagnosis and Classification………………………………………………. 3.2.6 Intervention Based on Fracture Classification………………………………….. 3.2.7 Duration from Injury to Surgery…………………………………………………….... 3.2.8 Wound Related Complications………………………………………………………....

28 28 29 29 29 30 30

3. Results …………………………………………………………………………………. 26 3.1 Results of the Search…………………………………………………………………. 26 3.2 Included Studies………………………………………………………………………... 27 3.2.1 Results of RCTs and Comparative Studies………………………………………... 27

3.3 Results of Randomized Controlled Trials……………………………………. 31 3.3.1 Patient Population………………………………………………………………………….. 31 3.3.2 Fracture Classification…………………………………………………………………….. 3.3.3 Intervention Bases on Fracture Classification…………………………………... 3.3.4 Randomization……………………………………………………………………………….. 3.3.5 Duration from Injury to Surgery…………………………………………………….... 3.3.6 Duration of Operative Time…………………………………………………………….. 3.3.7 Intraoperative and Postoperative Protocols……………………………………..

31 32 32 32 33 34

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3.3.8 Wound Related Complications…………………………………………………………. 34 3.3.9 Radiographic Assessment………………………………………………………………… 34 3.3.10 Assessment of Functional Outcomes……………………………………………….. 36 3.3.10.1 Maryland Foot Score………………………………………………………. 36 3.3.10.2 AOFAS……………………………………………………………………………. 36 3.3.10.3 CNHFA…………………………………………………………………………… 37 3.3.11 Assessment of Subtalar Joint Motion……………………………………………….. 37 3.3.12 Return to Work……………………………………………………………………………… 37 3.3.13 Time to Union………………………………………………………………………………... 38 3.3.14 Smoking and Diabetes……………………………………………………………………. 38

3.4.2 Fracture Classification……………………………………………………………………… 39 3.4.3 Intervention Bases on Fracture Classification……………………………………. 39 3.4.4 Duration from Injury to Surgery……………………………………………………….. 39 3.4.5 Duration of Operative Time……………………………………………………………… 39 3.4.6 Intraoperative and Postoperative Protocols……………………………………… 40 3.4.7 Wound Related Complications…………………………………………………………. 40 3.4.7.1 Infection………………………………………………………………………….. 40 3.4.7.2 Sural nerve Injury……………………………………………………………. 41 3.4.8 Radiographic Assessment………………………………………………………………... 42 3.4.9 Assessment of Functional Outcomes………………………………………………… 42 3.4.9.1 AOFAS……………………………………………………………………………... 42 3.4.9.2 SF-‐36………………………………………………………………………………. 43 3.4.9.3 FFI…….…………………………………………………………………………….. 43 3.4.9.4 Other Functional Scores………………………………………………….... 43 3.4.10 Assessment of Subtalar Joint Motion………………………………………………. 44 3.4.11 Return to Work……………………………………………………………………………… 44 3.4.12 Smoking and Diabetes……………………………………………………………………. 45

4.1.2Allocation Bias…………………………………………………………………………………. 47 4.1.3 Incomplete Outcome Data……………………………………………………………….. 48 4.1.4 Observer Bias………………………………………………………………………………….. 48 4.1.5 Bias Due to lack of Power…………………………………………………………………. 49 4.1.6 Selection Bias…………………………………………………………………………………... 50 4.1.7 Other Risk of Bias…………………………………………………………………………….. 50

3.4 Results of Comparative Studies…………………………………………………… 38 3.4.1 Patient Population…………………………………………………………………………… 38

4. Discussion ………………………………………………………………………………….. 46 4.1 Risk of Bias in the Included Studies…………………………………………….. 46 4.1.1 Blinding………………………………………………………………………………………….. 47

4.2 Effects of Treatment…………………………………………………………………… 52 4.2.1 Primary Outcomes…………………………………………………………………………… 52 4.2.1.1 Wound Related Complications………………………………………….. 52 4.2.2 Secondary Outcomes……………………………………………………………………….. 52 4.2.2.1 Quality of Life Assessment………………………………………………... 52 4.2.2.2 Return to Work………………………………………………………………… 53

4.3 Agreements or Disagreements with Other Studies……………………….. 53 5. Conclusion ………………………………………………………………………………….. 57 6. References ………………………………………………………………………………….. 59 7. Illustrations ………………………………………………………………………………….. 64 9. Appendices ………………………………………………………………………………….. 66

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ACKNOWLEDGEMENTS The author is grateful to Prof. James Barrie1 and Wendy Munro2 for their continuous supervision and guidance for completion of this work. 1. Consultant Foot and Ankle Surgeon Royal Blackburn Hospital Haslingden Road Blackburn BB2 3HH 2. Programme leader C719, Allerton Building University of Salford Salford M6 6PU

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ABBREVIATIONS (in the order of appearance in text) DIACF

Displaced Intra-‐articular Calcaneal Fractures

CT

Computed Tomography

ORIF

Open Reduction and Internal Fixation

MIRPF

Minimally Invasive Reduction and Percutaneous Fixation

NLM

National Library of Medicine

MeSH

Medical Subject Headings

PICO

Patients, Intervention, Comparison and Outcome

CASP

Critical Appraisal Skills Programme

RCT

Randomized Controlled Trial

IRB

Institutional Review Board

SAVE

Score Analysis of Verona

MFS

Maryland Foot Score

AOFAS

American Orthopaedic Foot and Ankle Society Hind Foot Score

CNHFA

Creighton Nebraska Health Foundation Assessment Scale

FFI

Foot Function Index

SF-‐36

Short-‐Form 36

EQ-‐5D

EuroQol 5D

VAS

Visual Analogue Scale

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ABSTRACT BACKGROUND Calcaneal fractures are the commonest tarsal bone fractures. The optimal management of displaced intra-‐articular calcaneal fractures remains controversial. Traditional method of treatment with open reduction and internal fixation carries high incidence of wound complications. Many authors have advocated minimally invasive techniques as an alternative approach; however they are associated with their own technical challenges. OBJECTIVES To systematically identify, assess for quality and synthesize research evidence available relating to the use of minimally invasive reduction and percutaneous fixation versus open reduction and internal fixation for displaced intra-‐articular calcaneal fractures. SEARCH METHODS Articles from 1999 to 2014 were searched through MEDLINE (PUBMED), Cochrane Library, Embase, ScienceDirect, Scopus and ISI Web of Knowledge using Boolean logic and text words. SELECTION CRITERIA Of the 565 articles identified initially, 8 were selected including 3 randomized controlled trials and 5 retrospective comparative studies. DATA EXTRACTION & ANALYSIS Data were extracted on a standardized form using PICO method and was systematically analyzed for quality using CASP tools. Risk of bias was assessed for each study.

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MAIN RESULTS These studies had a total of 949 patients with 1020 displaced intra-‐articular calcaneal fractures. Mean follow-‐up was 27.5 months. Of these, 534 (53%) were treated with minimally invasive technique and 481 (47%) were treated with open reduction and internal fixation. Overall incidence of wound complications was 3.7% (0-‐13%) in minimally invasive group and 18.2% (11.7%-‐35%) in open reduction group. CONCLUSION Overall quality of the available evidence is poor in support of either surgical technique due to small sample size, flaws in study designs and high risk of bias for various elements. Individual studies have reported minimally invasive technique to be an effective alternative with lower risk of wound complications; however good quality research with larger patient population and longer follow-‐ up duration is needed.

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KEYWORDS Calcaneus Intra-‐articular fractures Percutaneous fixation Minimally invasive approach Open reduction Wound infection

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1. INTRODUCTION 1.1 INCIDENCE Calcaneal fractures comprise 2% of all fractures in the human body (Ibrahim et al., 2007). They are the most common fractures in the tarsal bones, accounting for 60% of all the tarsal fractures (Rammelt & Zwipp, 2004). Most calcaneal fractures (60%) occur in patients who are still in their wage-‐earning age (i.e. 30 to 50 years old) (Siebe De Boer et al., 2014).

1.2 DISPLACED INTRA-‐ARTICULAR CALCANEAL FRACTURES (DIACF) Calcaneal fractures are broadly divided into intra-‐articular and extra-‐articular fractures. Approximately three-‐quarters (75%) of calcaneal fractures are intra-‐ articular and displaced fractures (Ibrahim et al., 2007). Majority of displaced intra-‐articular calcaneal fractures involves the posterior facet, which is the major weight-‐bearing surface of the sub-‐talar joint. These fractures typically result from high-‐energy trauma such as fall or jump from a height or high-‐speed road traffic accidents.

1.3 CLINICAL PRESENTATION Patients with calcaneal fractures present with a painful, swollen and bruised heel and the arch of the foot. There may be an associated obvious deformity. Patients are usually unable to weight-‐bear. Significant swelling may lead to blistering of

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the skin. Approximately 15% of all calcaneal fractures have an associated open wound and 5%-‐10% involve both heels (Sanders, 2000).

1.4 CLASSIFICATION Sanders classification system is used to assess intra-‐articular calcaneal fractures. This classification is useful not only in understanding the fracture patterns of the calcaneus, but also in predicting their outcome. Sanders classification is based on computed tomography (CT) scan and uses the coronal plane, where the posterior subtalar joint is at its widest and the sustentaculum tali is visible. It is based on the number of fracture lines with more than 2mm displacement. A displaced fracture with one fracture line extending through the posterior joint is called a type II fracture. Fracture with two fracture lines is called type III fracture, and type IV fracture displays three or more fracture lines. Fracture lines are lettered from lateral to medial as A, B and C. Hence three different forms of type II and III fractures exist, depending upon the location of fracture lines (Sanders, 2000) (Fig. 1).

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Figure 1. Sanders classification of displaced intra-‐articular calcaneal fractures (non-‐copyright image, courtesy of Dr. Matt Skalski, Radiopaedia.org)

1.5 RADIOLOGICAL ASSESMENT Conventional radiography is the primary imaging modality in cases of suspected fractures around the foot and ankle; however plain radiographs provide limited information for the assessment of complex fractures of tarsal bones. In particular, in cases of calcaneal fractures, the relationship of the multiple fracture fragments is difficult to appreciate on plain radiographs. Therefore in most cases supplemental imaging is needed to define the fracture characteristics and planning their optimal management (Dodson, Dodson, & Shromoff, 2008). Computed tomography (CT) is considered the modality of choice for calcaneus

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fractures before surgery for the reasons discussed above, and after surgical intervention in order to assess the accuracy of restoration of the anatomy (i.e. calcaneal width and length, Bohler’s angle and Gissane’s angle) and the congruency of the subtalar joint (Buckingham, Jackson, & Atkins, 2003).

1.6 MANAGEMENT The optimal management of displaced intra-‐articular calcaneal fractures is controversial (Gougoulias, Khanna, McBride, & Maffulli, 2009; Jiang, Lin, Diao, Wu, & Yu, 2012). Historically, DIACFs were treated non-‐operatively with a combination of rest, elevation, ice and immobilization with plaster cast, followed by physiotherapy and gradual mobilization (Sanders, 2000). However, this often required delayed reconstruction of the mal-‐united fracture, leaving the patients with a painful and stiff foot, which delayed or permanently prevented their return to work and other pre-‐injury activities (Sanders, Fortin, DiPasquale, & Walling, 1993). Until the 1970s, operative treatment was considered technically challenging, and often led to postoperative infection, mal-‐union, non-‐union and amputation (McLaughlin, 1963). During the last 20 years, improvements in anaesthesia, antibiotic prophylaxis, advances in principles of fixation, advances in materials, implants and computed imaging have led to improvements in outcome after operative treatment. This has popularized the fixation of most fractures, including those of the calcaneus as well. Operative treatments for DIACFs include open reduction and internal fixation (ORIF), minimally invasive reduction with percutaneous fixation (MIRPF) or primary arthrodesis (joint fusion). Controversies and variable opinion still exist among the foot and ankle surgeons regarding the choice of operative or non-‐operative treatment for

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displaced calcaneal fractures, however, a recently published multicentre randomized controlled trial on long-‐term results of calcaneal fractures showed that the patient-‐reported clinical, functional and quality of life outcomes were better after operative treatment at 8 to 12 years follow-‐up (Agren, Mukka, Tullberg, Wretenberg, & Sayed-‐Noor, 2014). Although advances in surgical techniques might have improved functional outcome for many patients, surgical fixation of these fractures is still technically challenging and carries the risks of complications, such as wound infection, sural nerve injury and failure of the implants (Backes et al., 2014; Chen, Zhang, Hong, Lu, & Yuan, 2011; Rammelt & Zwipp, 2004; Xia, Lu, Wang, Wu, & Wang, 2014). 1.6.1 OPEN REDUCTION AND INTERNAL FIXATION (ORIF) Open reduction and internal fixation (ORIF) with conventional plate via an extensile lateral L-‐shaped approach has been regarded as a standard treatment for displaced intra-‐articular calcaneal fractures because it provides an excellent exposure of the fracture and allows direct reduction of the depressed posterior facet fragment (Kline, Anderson, Davis, Jones, & Cohen, 2013). However, the extensile approach has been fraught with high incidence of wound related complications (5.8% to 35.3% reported in various studies), including wound edge necrosis, dehiscence, deep infection, formation of haematoma (due to the creation of a dead space between the lateral wall of the calcaneus and the flap), damage to sural nerve and increased length of operating time due to meticulous technique required for preparation and closure of the wound (Assous & Bhamra, 2001; DeWall et al., 2010; Folk, Starr, & Early, 1999; Stromsoe, Mork, & Hem, 1998; Tennent, Calder, Salisbury, Allen, & Eastwood, 2001; Weber, Lehmann,

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Sagesser, & Krause, 2008). 1.6.2 MINIMALLY INVASIVE REDUCTION AND PERCUTANEOUS FIXATION (MIRPF) In order to lower these wound related complications and soft tissue trauma, numerous minimally invasive procedures have recently been introduced, including percutaneous reduction and internal fixation, arthroscopically-‐assisted fixation, and minimal incision techniques via medial, modified lateral (the sinus tarsi approach), posterior, or combined approaches (DeWall et al., 2010; Schepers, 2011; Xia et al., 2014). Some of these minimally invasive techniques have become more popular than the others, depending on specific fracture patterns (Wu et al., 2012). Careful study of preoperative CT scan is vital before attempting minimally invasive reduction, as it helps the operating surgeon to understand the fracture anatomy. The surgeon must be aware of the approximate size of the displaced fragments and whether the articular surface is depressed medially, laterally or in total. The information obtained from CT scan also helps to choose the correct size of the bone punch and to direct it appropriately, as the intraoperative fluoroscopic lateral view of the hind foot can only help to locate the depressed fragment in the sagittal plane (Xia et al., 2014). Percutaneous reduction and fixation technique was mainly recommended for Sanders type II and type III fractures and good results have been reported (Chen et al., 2011; Tornetta, 2000). The major concern with the minimally invasive approach for these fractures is incomplete reduction, especially in cases of complex fracture patterns. In addition, the cancellous bone screw and the K-‐wire commonly used in minimally invasive techniques may not be able to provide

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adequate restoration of the width and the height of the calcaneus, and some loss of reduction can occur subsequently (Gavlik, Rammelt, & Zwipp, 2002; Rammelt & Zwipp, 2004; Stulik, Stehlik, Rysavy, & Wozniak, 2006).

1.7 WHY ARE CALCANEAL FRACTURES IMPORTANT? The ideal treatment for displaced intra-‐articular calcaneal fractures remains a topic of intense debate. However, it is generally agreed that the restoration of intra-‐articular anatomy is essential to restore the normal gait biomechanics, early return to work and minimize the need for subsequent subtalar arthrodesis (Kumar et al., 2014; Rammelt & Zwipp, 2004; Sanders, 2000). During the recent years, a lot of attention has been paid to the extensile lateral approach with regards to soft tissue management by creating full-‐thickness flaps and a “no-‐ touch” technique. However, despite the advances in meticulous soft tissue handling techniques, postoperative wound related complications still occur (Benirschke & Kramer, 2004). The economic impact of calcaneal fractures to the patients and the society is considerable and is a consequence of extended hospital stay, cost of treatment, residual pain, time to mobilization and delayed return to work (Schepers et al., 2007). Time to resume professional work could be as much as five to ten months (Buckley et al., 2002). Some studies have reported that a considerable number of patients may not be able to resume their work even after one year of sustaining the injury (Schepers, van Lieshout, van Ginhoven, Heetveld, & Patka, 2008; Siebe De Boer et al., 2014). These fractures may remain symptomatic for one to two years and secondary arthrodesis may be needed in up to 16% of the non-‐

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operatively treated patients (Buckley et al., 2002).

1.8 WHAT IS ALREADY KNOWN AND WHAT IS UNKNOWN? Historically, displaced calcaneal fractures were treated non-‐operatively, but this frequently led to mal-‐union, poor function, stiffness and inability to return to work and other physical activities (Sanders, 2000). During the last 20-‐30 years, open reduction and internal fixation using the extensile lateral approach became the preferred treatment for these fractures, paying a careful consideration to patient-‐related risk factors including smoking, diabetes and other significant co-‐ morbidities (Buckley et al., 2002). This approach is considered to offer certain benefits, which include adequate exposure of the fractured lateral wall of the calcaneus and the subtalar joint, appropriate reduction of the subtalar and the calcaneocuboid joints, insertion of a compression screw into the sustantaculum tali and stabilization of the fracture by internal fixation plate (Kline et al., 2013; Rammelt & Zwipp, 2004; Wu et al., 2012; Xia et al., 2014). However, the potential surgical risks remain a major challenge. Despite of the fact that modern surgical intervention has improved post-‐fracture outcome for many patients, there remains a lack of consensus on the use of surgery for the optimal management of calcaneal fractures. During more recent years, minimally invasive techniques have been advocated by many studies with reports of fewer complications and similar outcomes compared to the extensile approach (Arastu, Sheehan, & Buckley, 2014; Ebraheim, Elgafy, Sabry, Freih, & Abou-‐Chakra, 2000; Hammond & Crist, 2013; Rammelt, Amlang, Barthel, Gavlik, & Zwipp, 2010; Schepers et al., 2007; Walde,

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Sauer, Degreif, & Walde, 2008). However the literature lacks a comprehensive review to assess the quality and strengths of the available evidence to support the use of either surgical approach. In view of many published studies in the recent years with reports of similar outcomes of the two approaches, it is important to analyze their collective outcomes in order to search for stronger evidence.

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2. METHODOLOGY 2.1 RESEARCH AIM •

To systematically identify, assess for quality and synthesize research evidence available relating to the use of minimally invasive reduction and percutaneous fixation versus open reduction and internal fixation for displaced intra-‐articular calcaneal fractures.

2.2 RESEARCH OBJECTIVES •

To identify methodological studies comparing the practice of minimally invasive reduction techniques with standard and traditionally used open reduction technique

•

To evaluate the quality of the available studies against a set criteria

•

To synthesize the results of the studies and relate their implications to the routine surgical practice in the management of calcaneal fractures

2.3 LITERATURE SEARCH 2.3.1 INCLUSION CRITERIA 2.3.1.1 PATIENT POPULATION Studies reporting the outcomes of the following were included: -‐

Displaced intra-‐articular calcaneal fractures (Sanders types II, III and IV) 19

-‐

Patients above the age of 16 years

-‐

Closed fractures

-‐

Acute fractures (operated on within 3 weeks of sustaining the injury)

2.3.1.2 INTERVENTION Studies comparing the outcomes of the following were included: -‐

Minimally invasive reduction and percutaneous fixation

-‐

Open reduction and internal fixation using the extensile lateral approach

2.3.1.3 OUTCOMES Studies that reported the results of calcaneal fractures with reference to validated functional scoring systems were included. 2.3.2 EXCLUSION CRITERIA 2.3.2.1 PATIENT POPULATION Studies that reported the results of the following were excluded: -‐

Open calcaneal fractures

-‐

Calcaneal fractures associated with multiple other injuries

-‐

Calcaneal fractures associated with neurological or vascular injuries

-‐

Calcaneal fractures in patients with alcohol excess and drug users

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2.3.3.2 INTERVENTION Studies that reported the outcomes of the following were excluded: -‐

Non-‐operative treatment of calcaneal fractures

-‐

Comparison of non-‐operative treatment with surgical treatment

-‐

Studies reporting the results of open reduction alone

-‐

Studies reporting the results of minimally invasive surgery alone

2.3.3 ELECTRONIC DATABASE SEARCH An extensive search was performed through the available literature from 1999 to 2014. Search was limited to articles in English language only. The databases that were searched included MEDLINE (PUBMED), Cochrane Library (Cochrane Systematic Reviews and Cochrane Bone, Joint and Muscle Trauma Group), Embase, ScienceDirect, Scopus and ISI Web of Knowledge. The databases chosen were used to provide a variety of medical references, although some overlap was found between different databases. 2.3.4 SEARCH STRATEGY 2.3.4.1 MeSH TERMS The National Library of Medicine’s (NLM) Medical Subject Headings (MeSH) terms were selected and used along with text words. MeSH terms provided a consistent way to retrieve information where different terms had been used by authors for the same concept. However, text words were also useful, as the indexers don’t always incorporate certain pathologies into the index.

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2.3.4.2 KEYWORDS The search strategies used the keywords: “fracture calcaneus, calcaneous, calcaneal; surgical treatment, management; open reduction; minimally invasive; percutaneous reduction; internal fixation; Sanders”. Initially, in order to identify the surgical techniques for the treatment of displaced intra-‐articular calcaneal fractures in adults (Sanders II and III), the keywords were used combined by Boolean logic (AND and OR): “fracture calcaneus OR calcaneous OR calcaneal AND surgical treatment OR management”. Afterwards the keywords were used combined by Boolean logic relating to the treatment techniques: “fracture calcaneus OR calcaneous OR calcaneal AND surgical treatment OR management AND open reduction OR minimally invasive OR percutaneous reduction OR internal fixation”. 2.3.5 TYPES OF STUDIES Two types of relevant study designs were identified. Prospective randomized controlled trials (RCTs) and comparative retrospective clinical studies, which compared the outcomes of minimally invasive techniques with open reduction and internal fixation for displaced intra-‐articular calcaneal fractures were eligible for inclusion. Retrospective studies were also included in the review because of the limited types and number of studies available. 2.3.6 DATA EXTRACTION Data extraction was carried out keeping the focus on maintaining quality and research objectives. A standardized extraction form (Microsoft Excel®) was used to record the data. The parameters used in the extraction form addressed the

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concepts of bias, variability and the quality of the reporting. Clear definitions for the responses of ‘yes’, ‘no’ and ‘unclear’ were recorded against each parameter. The author and a reviewer (JB) independently examined the titles and abstracts of the articles identified in the search as potentially relevant trials and studies and reached a consensus. STAGE I: In the first stage, the apparent studies according to title or abstract, which presented surgical interventions for the treatment of displaced intra-‐articular calcaneal fractures were identified. STAGE II: In the second stage the studies that fulfilled the inclusion criteria, as discussed earlier, were identified. Later on full texts of these articles were obtained. Endnote® software was used to organize and manage the articles throughout the process of manuscript preparation. 2.3.7 APPRAISAL OF QUALITY OF STUDIES PICO method and CASP tools were used to appraise the selected studies and their results. PICO method (Population, Intervention, Comparison and Outcome) was selected because of being widely used in research and is considered helpful to assist in organizing and focusing the foreground question into a searchable query. Dividing into the PICO elements helps to identify search terms and concepts to use in the process of searching the literature. CASP tools (Critical Appraisal Skills Programme) assess both internal and external validity of a study

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and address the epidemiological principles behind the study types with particular attention on the study validity. All the study tools are divided into three sections relating to internal validity, the results and their relevance to practice. The reason for selecting these tools was to examine the validity of the selected studies, analyze their results and appraise their applicability and generalizability in clinical practice. Two-‐tailed t-‐test was used to analyze the significance of timing of surgery and incidence of wound related complications in the two groups. Fisher’s exact test was used to analyze the categorical values in the data. The p value of less than 0.05 was considered significant. The reasons for inclusion and exclusion were documented for each study and there were no disagreements between the author and the reviewer (JB) regarding inclusion and/or exclusion of the selected studies. In relation to the collection of data, the information was recorded on a standardized form to gather the following parameters, which are also summarized in the Appendices 1 and 2: METHODS: question from the survey, study design, sample size, randomization and blinding process, Sanders classification (type II to IV), details of surgical techniques used, duration from injury to surgery, assessment of bias related to allocation, assessment, incomplete outcome data, selective reporting, observer bias, duration of the postoperative follow-‐up and statistical calculations used. PARTICIPANTS: according to inclusion and exclusion criteria, number of fractures and age bracket, surgical technique adopted, incidence of superficial

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and deep infection and other wound related complications, clinical and functional outcome according to the validated functional scoring systems, radiological assessment based on plain radiographs and/or CT scans, ethical approval and conflict of interests.

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3. RESULTS

3.1 RESULTS OF THE SEARCH By using the search strategies described earlier, in stage I, 565 articles were identified related to the surgical management of calcaneal fractures. In stage II, 48 articles were identified related to the use of minimally invasive reduction and percutaneous fixation and open reduction and internal fixation for displaced intra-‐articular calcaneal fractures. Their titles and abstracts were reviewed and by strictly following the inclusion and exclusion criteria, eight articles were selected for final inclusion. A flow chart of the study selection process is presented in Figure 2.

Figure 2. Flow chart of selection of studies

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3.2 INCLUDED STUDIES 3.2.1 COMBINED RESULTS OF RCTs AND COMPARATIVE STUDIES The literature search identified three prospective randomized clinical trials (RCTs) of surgical treatments of Sanders II, III and IV intra-‐articular calcaneal fractures in adults, which directly compared the outcomes of minimally invasive reduction and percutaneous fixation with open reduction and internal fixation using the extensile lateral approach. In addition, there were five comparative studies found, which directly compared the results of these two methods of fixation for displaced intra-‐articular fractures. Basic demographic data of the included studies is summarized in Table 1.

Mean F/U (Months)

ORIF

MIRPF

No of Fractures

No of Patients

Type of Study

Studies

Duration (Years)

Year Published

Table 1.

Xia et al.

2014

3.5

RCT

108

117

64

53

19

Kumar et al.

2014

1.5

RCT

42

45

22

23

12

Chen et al.

2011

2.5

78

78

38

40

24

De Boer et al.

2014

10

110

110

61

49

72

Kline et al.

2013

3

112

112

33

79

30

Wu et al.

2012

6

329

383

213

170

12

De Wall et al.

2010

7.5

RCT Retrospective case-‐control Retrospective case series Retrospective case-‐control Retrospective case-‐control

120

125

79

41

23

Weber et al.

2008

11

Retrospective case-‐control

50

50

24

26

28

Total

949

1020

534

481

27.5

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3.2.2 ETHICAL STANDARDS The three randomised controlled trials were approved by the relevant ethics committees of the individual institutions where they were performed and their authors followed the essential ethical standards (Chen et al., 2011; Kumar et al., 2014; Xia et al., 2014). The other five comparative studies obtained approval from Institutional Review Board (IRB) related to each individual performing hospital and were performed in accordance with the ethical standards (De Boer et al., 2014; DeWall et al., 2010; Kline et al., 2013; Weber et al., 2008; Wu et al., 2012). Informed consents were obtained from all the patients for all these studies prior to their enrollment in to each study. The weighted average duration of all the studies was 5.6 years (18 months to 11 years). 3.2.3 INCLUSION AND EXCLUSION CRITERIA All these studies had similar inclusion and exclusion criteria. The fractures included, were displaced, intra-‐articular and closed. Displacement was defined as ‘more than 2mm gap’ at the fracture site in 7 studies and as ‘more than 1mm gap’ in one study (Kumar et al., 2014). Patients were excluded if they were below 16 years of age, had open fractures, multiple injuries, severe medical co-‐morbidities and peripheral vascular disease. Long-‐ term smokers were excluded in one study (Xia et al., 2014). Patients with diabetes were excluded in one study (Chen et al., 2011) and patients with alcohol excess and drug users were excluded in another study (De Boer et al., 2014).

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3.2.4 PATIENT POPULATION AND INTERVENTION The eight included studies had a total of 949 patients (average: 118 per study; range: 42 to 329) with 1020 displaced intra-‐articular calcaneal fractures (average: 127; range: 45 to 383) (Table 1). The weighted average follow-‐up was 27.5 months (range: 12 to 72 months). Of these 1020 fractures, 534 (53%) were treated using minimally invasive reduction and percutaneous fixation and 481 (47%) were treated with open reduction and internal fixation via the extensile lateral approach. Mean age of the patients in the minimally invasive group was 38.6 years and in the ORIF group was 38.2 years. 3.2.5 FRACTURE DIAGNOSIS AND CLASSIFICATION All these studies defined the fracture types based on CT scans according to Sanders classification system. Combining all the patients in these studies, there were 591 type II fractures (58%) and 349 were type III fractures (36%). Four of these studies also included type IV fractures and there were 67 type IV fractures (6%) included in the final outcomes of these studies (Chen et al., 2011; De Boer et al., 2014; Wu et al., 2012; Xia et al., 2014). 3.2.6 INTERVENTION BASED ON FRACTURE CLASSIFICATION Of all the type II fractures, 308 (52%) fractures were treated with minimally invasive reduction and percutaneous fixation and the remaining 283 (48%) were treated with open reduction and internal fixation using the extensile lateral approach. Of all the type III fractures, 177 (51%) fractures were treated with minimally invasive technique and 172 (49%) were treated with the extensile approach. Of all the type IV fractures, 37 (55%) fractures were fixed with

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minimally invasive technique and 30 (45%) were treated with the extensile lateral approach. The details of Sanders types II, III and IV are summarized in Table 2. Table 2.

Studies Xia et al. Kumar et al. Chen et al. De Boer et al. Kline et al. Wu et al. De Wall et al. Weber et al.

Type 2 treated with MIRPF 39 7 29 46 20 115 32 20

Type 2 treated with ORIF 31 9 32 38 42 92 19 20





Total

308

283

177

172

37

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3.2.7 DURATION FROM INJURY TO SURGERY The average combined duration from injury to surgery in the minimally invasive group was 7 days and in the open reduction group was 10 days, the difference being statistically significant (p=0.01). The main decision factor on the timing of surgery described in all the studies was the condition of soft tissues (i.e. swelling, blisters). 3.2.8 WOUND RELATED COMPLICATIONS The average combined reported incidence of wound related complications in patients treated with the minimally invasive technique was 3.7% (0 to 13%, 20 of 534 fractures) compared with 18.2% (11.7% to 35%, 88 of 481 fractures) in patients treated with the open reduction and internal fixation. This was found significantly lower in the minimally invasive group (p=0.005). Wound related

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complications and timing of surgery for each surgical technique described in individual studies are listed in Table 3. Table 3.

Studies Xia et al. Kumar et al. Chen et al. DeBoer et al. Kline et al. Wu et al. DeWall et al. Weber et al.

Wound Complications MIRPF Nil Nil 1 (1.2%) 8 (13%) 2 (6%) 4 (1.8%) 5 (6%) 1 (4.2%)

Wound Complications ORIF 10 (15%) 7 (30%) 5 (12.5%) 8 (16%) 23 (29%) 20 (11.7%) 15 (35%) 4 (15.3%)

Injury to Surgery MIRPF (days) 7.4 8.6 5 2 10 5.7 9.3 8

Injury to Surgery ORIF (days) 7.4 12.4 10 6 15 5.7 13.6 8

Total

20 (3.7%)

88 (18.2%)

7

10

3.3 RESULTS OF RANDOMIZED CONTROLLED TRIALS 3.3.1 PATIENT POPULATION The three RCTs had a total of 228 patients (range: 42 to 108) with 240 displaced intra-‐articular calcaneal fractures (range: 45 to 117) (Chen et al., 2011; Kumar et al., 2014; Xia et al., 2013). The average follow-‐up was 18.3 months (range: 12 to 24 months). The average duration was 2.5 years per trial (range: 1.5 to 3.5 years). All the RCTs had comparable number of patients in each group and both the groups had similar distribution of patients with regards to their age, gender and medical co-‐morbidities without any statistically significant differences. 3.3.2 FRACTURE CLASSIFICATION There were a total of 147 type II Sanders fractures, 76 type III fracture and 17 type IV fractures in the three trials (Table 2).

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3.3.3 INTERVENTION BASED ON FRACTURE CLASSIFICATION Minimally invasive techniques were used in 75 type II fractures, 36 type III fractures and 6 type IV fractures. Open reduction and internal fixation was used in 72 type II fractures, 40 type III fractures and 11 type IV fractures (Table 2). 3.3.4 RANDOMIZATION In the RCT by Xia et al. (2014), the patients were randomized by the method of coin tossing by one of the authors who was kept blind till the end of the study in order to reduce the bias from the treating surgeons. In addition, all the patients and the statistical analyst were also kept blind till the end of the study. In the RCT by Kumar et al. (2014) the patients were randomized by lottery method at the time of admission but prior to obtaining a preoperative CT scan to avoid allocation bias, therefore the operating surgeons had no control of fracture distribution according to Sanders types between the groups. However, this allocation method led to an unequal distribution, with more type II fractures undergoing minimally invasive surgery in this trial. In the third RCT by Chen et al. (2011) the patients were randomly allocated into 2 groups, however, the authors did not describe any specific randomization protocol. 3.3.5 DURATION FROM INJURY TO SURGERY The average duration from the time of injury to undergoing surgery was 7 days (range: 5 to 8.6 days) in the MIRPF group compared with 10 days (7.4 to 12.4 days) in the ORIF group.

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3.3.6 DURATION OF OPERATIVE TIME Xia et al. (2014) reported that the average duration of the operative time was significantly shorter in the minimally invasive group compared to the ORIF group, and was 62 minutes and 93 minutes in both the groups respectively (p