Arthroscopic Management of Distal Radius Fractures

Francisco del Piñal EditorChristophe MathoulinRiccardo LuchettiCo-Editors

Arthroscopic Management of Distal Radius Fractures

ISBN: 978-3-642-05353-5 e-ISBN: 978-3-642-05354-2

DOI: 10.1007/978-3-642-05354-2

Springer Heidelberg Dordrecht London New York

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Chapter 2: all figures© David J. Slutsky 2007. All Rights Reserved.

Chapter 4: Figures 1, 6, 8–11, and 16–19.© Francisco del Piñal 2009. All Rights Reserved.

Chapter 14: 11, 13, 14, and 26.© Francisco del Piñal 2009. All Rights Reserved.

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Dr. Francisco del PiñalPrivate practice and Hospital Mutua MontañesaCalderón de la Barca 16-entlo.39002 SantanderSpaindrpinal@drpinal.com

Dr. Christophe MathoulinProfessorClinique Jouvenet Institut de la Main6 square Jouvenet75016 ParisFrancecmathoulin@orange.fr

Dr. Riccardo LuchettiRimini Hand Surgery and Rehabilitation CenterMultimedica Policlinic, MilanoVia Pietro da Rimini, 447900 RiminiItalyrluc@adhoc.net

v

Supported by EWAS

vii

Dedication

To my kids Lucía, Guillermo, and Miguel.

To my admired mentors: G. Ian Taylor, who taught me the importance of anatomy and of toying with it; Ian T. Jackson, who showed me that surgery was science before art; to Luis R. Scheker, a virtuoso, who sparked my interest in hand surgery, and to all surgeons who one way or another have influenced me throughout this journey. Paco Piñal

I would like to dedicate this book to all EWAS members without whom none of this magnificent adventure would have been possible. I would particularly like to thank all the Presidents of our small but efficient society who worked hard to achieve the reputation and quality which now has established EWAS as a recognized, respected, and consulted scientific society.

Finally, I would especially like to thank our current President Francisco del Piñal, who worked tirelessly countless hours, in order to publish this very good book. Christophe Mathoulin

I personally wish to dedicate a few words to the people who have helped us behind the scenes. Those people are our families (wives, partners, children, and so on). Our families harmonize our lives, help us whilst staying in the shade, support us when difficulties arise and, last but not least, stimulate us in our profession, both surgical and scientific.

I do not wish to remember how many hours we have deprived them of, how many hours we have spent with books open in front of us, working on our computers to write a chapter. I prefer to remember what our editor in chief (Paco) managed to do: he not only produced his own chapter, but also corrected all the others, giving the authors advice

and directing the drafts in conformity with his thoughts, and at the same time keeping up with work, congresses, and collateral activities.

A big thank you to everybody! And of course thank you, Paco and Christophe, and all the authors.

At last this book will mark an era! Riccardo Luchetti

viii Dedication

ix

Foreword

Seeing is believing. This is the title of a new campaign promoted by the International Agency for Prevention of Blindness to raise funds to help tackle avoidable loss of sight in poorly developed countries, truly an admirable initiative. This book could have used a similar leitmotiv: if you see what happens inside of a joint, you will be able to believe in your patient’s symptoms. But it would not be right. Arthroscopy is not out there just to make a diagnosis; it was not developed just to certify that the patient’s complaints are based on something physical. Arthroscopy was introduced to help patients, to make our treatments more reliable, to have better control of our pro-cedures. It is merely a tool, indeed, but a marvelous one which nobody should under-score among all surgical options we have when it comes to solving wrist trauma.

Seeing is understanding. This could be another leitmotiv for these authors’ cam-paign to get more hand surgeons to incorporate arthroscopy in their practices. Certainly, mastering these newly developed techniques help understanding the patient’s problems. But again, that statement would also be misleading for not always what we see through the scope is the real cause of dysfunction. The enemy may be outside of the capsular enclosure. Indeed, arthroscopy provides lots of useful infor-mation, but the surgeon need not accept biased interpretations of the patient’s prob-lem based only on what appears on the screen. Clinical judgment needs always to rely on all sorts of information, the clinical examination being most important.

Seeing is delivering. This is another possible motto for this book. If you see what you do, you will be able to deliver a better job no matter how difficult that might be. Nobody solves a puzzle without looking at it. Nobody would be happy to leave unre-duced a badly displaced intra-articular fragment of a distal radial fracture if one can see it. Of course, fluoroscopy is what most of us have learned to use when reducing a distal radial fracture, but we must admit that not even the best image intensifier does offer such clear images of joint congruity as arthroscopy does. Indeed, if you see it better and you have the right skill to reduce those fragments more anatomically, your efforts will be rewarded by a higher self-esteem, but most importantly by your patient.

Seeing is preventing. If you are the first to see the enemy coming, you are better prepared than the others to work on a proper line of defense before any damage has been caused. Without a thorough perception of a problem, one can hardly prevent it from happening. A bone fragment may appear stable under fluoroscopy, but this may be a false impression which could endanger our results. Indeed, steadiness of a frag-ment can only be ensured by challenging its stability with a palpating prove . Certainly, using arthroscopy not only helps in the diagnosis and treatment but also, and most importantly, in the prevention of complications.

x Foreword

Enclosed in these pages is a synthesis of what a group of talented arthroscopists have learned in their search for better ways to solve wrist problems. There is a large amount of technical tips in this book that will facilitate our treatments; new indica-tions may attract our attention. There is enormous interest in providing detailed how-to-do descriptions that will guide our steps toward perfecting each one’s personal arthroscopy abilities. But above all, there is a good account of a number of mistakes that need not to be repeated, and these authors learned the hard way about all of this. Let’s be grateful that they are willing to share this vast knowledge with us, the ones who did not dare to be pioneers in this field. Let’s use their experience to make less steep our learning curves.

To those who believe that there is not a real novelty in the field of wrist trauma reconstruction, here is this book to show them wrong. There are new ways of solving wrist problems; new ways that not only have been made possible as a result of the introduction of arthroscopy but also, and most importantly, as a result of the hard work and enthusiasm of those who pioneered the use of this tool in this environment. Wrist arthroscopy is here to stay, because it helps obtaining better results with less morbidity than open surgery. Arthroscopy is here to stay, because there are profes-sionals, like the ones signing these chapters, who have collected enough experience for us to get an easy start. And this is what this book is all about: a condensed descrip-tion of the indications, pearls, and pitfalls of this wonderful tool.

Because arthroscopy is here to help our patients, let’s make the most of it.

Institut Kaplan, Barcelona Marc Garcia-Elias

xi

“If a method produces better results, one must master any difficulty it presents and learn to do it well” (talking on Herbert screw).

Nicholas Barton. J Hand Surg 1997;22B:153

I still remember when we were stared at in meetings as if we were aliens (and grouped under the “arthroscopists”). This feeling of being an “outsider” was not strange to me at all, as when several of us started to carry out what was called “third-generation microsurgery,” we provoked the same feelings. This convinced me that we were on the right path, and that arthroscopy was the right tool and persuade me to keep on using in it in more and more applications.

One of the most fascinating fields where we were able to apply our maverick ideas was to distal radius fractures with articular involvement. The arthroscope allowed us to have a magnified view of the reduction, to detect associated chondral or ligamen-tous injuries, and to treat many of them. It was exciting to realize how many things we could see and fix through such tiny holes!

Surprisingly, however, and despite growing literature supporting the role of arthroscopy, many surgeons are still reluctant to systematically use the arthroscope when treating distal radius fractures, when we all agree that fluoroscopy is quite inac-curate. Two of the arguments given are that no one has yet proved that the scope is better than traditional treatments in prospective-randomized studies, and the second one, more difficult to voice, is that the operation is technically difficult. Hence, why complicate one’s life with the scope if there are no advantages to be gained?

Regarding the first argument, I must admit that the scientific purists are right: there are not yet Level 1 studies that have shown that arthroscopy is so much better than traditional methods in the treatment of distal radius fractures. One has to accept that innovation goes well ahead of comparative studies, and it will take some time before such studies are available. The problem is compounded by the fact that there are so many variations in a distal radius fracture that we will need a long time before each subtype is properly assessed. Can our patients wait so long to benefit from a method that allows us to see the reduction with minimum morbidity and maximum accuracy? After all, there have been many studies showing that articular congruity is the most important prognostic factor after an articular fracture, and the scope is no doubt the tool to see inside a joint.

Another question altogether is if it is easy to carry out an arthroscopic-assisted reduction of articular distal radius fractures. The answer is no. As a matter of fact, things have become more and more sophisticated since the arthroscopic management of distal radius fractures has advanced enormously in the last 15 years. Renowned specialists around the world have been brought together in this book to share with us

Preface

xii Preface

their innovative way of dealing with some of the problems. Furthermore, beginners will find the basics succinctly explained by masters in a step-by-step manner. The reader may find it perplexing that each of us might manage the same injury in a some-what different manner. This variability is explained by the fact that very little was written at the time we began our journey seeking the same goal: anatomical reduction with minimal trauma. Don’t worry! Choose the way that suits you best and go ahead….after all, all roads lead to Rome. My advice is, “build your own foundations and steadily move forward; don’t leap into too complicated cases before you are con-fident with the simple ones.” As an example, as a starting point, simply washing out the hematoma would be a good exercise in order just to be acquainted with the set-up.

It is pertinent to stress at this point that the arthroscope is just a tool to improve reduction, and expertise in the management of distal radius fractures with the classic techniques is more important than the arthroscopic part itself. The maxim is, ”classics first and then innovation” – ignoring this will inevitably lead to unwanted problems and bad results.

If you are yet not convinced that the scope is the tool, as a simple exercise I recom-mend you to insert an arthroscope inside a joint with a fracture that fluoroscopically seems to be reduced. Who knows? You may just change your mind, and find this book useful. After all “seeing is believing,” as Marc Garcia-Elias writes in the Foreword.

Last, but no least, I would like to thank all authors for having accepted to become part of this project, and to Christophe and Riccardo, and the EWAS group for sup-porting me on it.

Editor in chief Francisco del PiñalPresident of the European Wrist Arthroscopy Society

Contents

1 Pre-Operative Assessment in Distal Radius Fractures. . . . . . . . . . . . 1Gregory I. Bain

2 Portals and Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13David J. Slutsky

3 Management of Simple Articular Fractures . . . . . . . . . . . . . . . . . . . . 27Ferdinando Battistella

4 Treatment of Explosion-Type Distal Radius Fractures . . . . . . . . . . . 41Francisco del Piñal

5 Management of Distal Radius Fracture-Associated TFCC Lesions Without DRUJ Instability . . . . . . . . . . . . . . . . . . . . . . 67Alejandro Badia

6 Arthroscopic Management of DRUJ Instability Following TFCC Ulnar Tears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73Andrea Atzei

7 Radial Side Tear of the Triangular Fibrocartilage Complex . . . . . . . 89Toshiyasu Nakamura

8 Arthroscopic Management of Scapholunate Dissociation . . . . . . . . . 99Tommy Lindau

9 Lunotriquetral and Extrinsic Ligaments Lesions Associated with Distal Radius Fractures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109Didier Fontès

10 Management of Concomitant Scaphoid Fractures . . . . . . . . . . . . . . . 117Christophe Mathoulin

11 Perilunate Dislocations and Fracture Dislocations/ Radiocarpal Dislocations and Fracture Dislocations . . . . . . . . . . . . . 127Mark Henry

xiv Contents

12 The Role of Arthroscopy in Postfracture Stiffness . . . . . . . . . . . . . . . 151Riccardo Luchetti

13 Treatment of the Associated Ulnar-Sided Problems . . . . . . . . . . . . . . 175Pier Paolo Borelli and Riccardo Luchetti

14 Arthroscopic-Assisted Osteotomy for Intraarticular Malunion of the Distal Radius . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191Francisco del Piñal

15 The Role of Arthroscopic Arthrodesis and Minimal Invasive Surgery in the Salvage of the Arthritic Wrist: Midcarpal Joint . . . . 211Joseph F. Slade

16 Arthroscopic Radiocarpal Fusion for Post-Traumatic Radiocarpal Arthrosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225Pak-cheong HO

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

1F. del Piñal et al. (eds.), Arthroscopic Management of Distal Radius Fractures, DOI: 10.1007/978-3-642-05354-2_1, © Springer-Verlag Berlin Heidelberg 2010

Introduction

The determinants of clinical outcome following distal radial fracture are multi-factorial and may provide sev-eral challenges to the treating surgeon. These can be considered under the following headings: patient history including medical co-morbidities, functional demands and injury history; examination findings including the condition of the soft tissue envelope and neurological status; radiographic parameters including fracture char-acteristics, articular involvement, stability features and associated injuries to the ulna or carpus. Finally, classifi-cation of the injury may aid treatment selection and prognostic prediction. With vigilant pre-operative plan-ning, the surgeon can ensure the best outcome for an individual patient.

History

The expectations of the individual and society have increased over the past few decades such that poor results are less acceptable in modern hand surgery. Functional disability and degenerative osteoarthritis may result from distal radius fractures, but they may not correlate with the subjective assessment of outcome or satisfaction. Age, hand dominance, occupation, compli-ance and functional demands should all be considered.

Details of the mode of injury should be sought as this will inform our understanding of the energy applied to the limb. Most distal radius fractures are sustained as a result of a fall from standing height with the wrist in an extended position. These are considered low-energy injuries. In most cases the soft tissue injury is minimal, although in elderly patients with a more fragile soft tis-sue envelope and poorer protective reflexes the injury may be more extensive. With the wrist extended, the point of maximal load in the scaphoid and lunate fossa of the distal radius moves from a relatively volar posi-tion towards the dorsal lip. Therefore, an axial load applied in this position will result in the typical injury pattern with comminution of the dorsal cortex and dor-sal angulation of the distal fragment.

A fall from a height of greater than two metres, sporting injuries and motor vehicle accidents are high-energy injuries. The soft tissue envelope may be sig-nificantly disrupted in these patients, and the fracture may be comminuted. The clinician should be alert to the possibility of injury elsewhere in the ipsilateral extremity, other musculoskeletal trauma and injury to other systems.

The young patient with a distal radius fracture will typically have been subject to a high-energy injury with complex fracture patterns and extensive soft tissue damage but will have high functional demands. The injury will often require invasive treatment to restore distal radial anatomy. Wrist function may also be criti-cal in the older patient who, for example, requires the use of a walking aid to maintain independence, or suf-fers dysfunction of the contralateral arm. The patient with multiple injuries requires further consideration, especially those who may require use of their arm to aid their mobility or rehabilitation.

Medical co-morbidities are a critical factor when considering operative management. Benefits of various

Pre-Operative Assessment in Distal Radius Fractures

Gregory I. Bain

G. I. Bain Department of Orthopaedics and Trauma, University of Adelaide, Royal Adelaide and Modbury Public Hospital, 196, Melbourne Street, North Adelaide, SA 5006, Australiae-mail: greg@gregbain.com.au

1

2 G. I. Bain

treatment options must be weighed against the risks of operative intervention in systemic illnesses. Specialists from other medical disciplines should be consulted if necessary, and patients must be counselled appropri-ately regarding the choice of treatment and likely prog-nosis. Those with low-energy fractures or other evidence of osteoporosis should be investigated appro-priately with bone mineral density scans and com-menced on suitable therapy.

Counselling an individual patient on the likely recovery period and functional outcome can be chal-lenging. Excellent function may result despite defor-mity and malunion in some patients, where others experience long-term pain and disability in the pres-ence of an apparently minor fracture [11, 59]. As a general rule, the closer an injury to normal anatomical limits, the less functional disturbance can be expected following union [41]. The majority of patients experi-ence a good final result [9, 31, 59, 66], but complete functional recovery is uncommon [5].

Examination

Quality of the skin and soft tissues around the wrist are critical in managing distal radius fractures. The patient may have systemic disease involving the skin, such as eczema or psoriasis. Skin abnormalities near planned incision or pin sites may greatly increase the risk of infection and force an alteration of the desired treat-ment plans. Unlike trauma in some other body regions, it is uncommon for soft tissue swelling to delay defini-tive management of a wrist fracture. Care should be taken with surgical timing, particularly, in high-energy injuries with extensive soft tissue contusion, fracture blisters or open wounds. Open wounds in the region of a fracture should be assumed to signify an open frac-ture until proven otherwise in the operating theatre. Surgical debridement and wound lavage should be conducted in the operating theatre as soon as practical.

Vascular or neurological compromise should also expedite treatment. In a grossly displaced fracture, urgent closed reduction and splintage in the emergency department will decrease tension on soft tissue struc-tures. Compartment syndrome is a rare occurrence in distal radius fractures, but may occur in high-energy forearm fractures [58, 63]. In regions of severe

soft tissue loss or deficit, external fixation may be the preferred treatment option to stabilize a wrist fracture. Internal fixation may still be considered in combina-tion with soft tissue coverage procedures in combina-tion with a plastic surgeon.

Median nerve compression symptoms may arise following distal radial fracture, or pre-existing symp-toms may deteriorate following fracture [35, 62]. Acute symptoms may relate to nerve compression from frac-ture displacement, and these will often resolve within weeks of fracture reduction. Alternately, symptoms may progress and require operative carpal tunnel decompression [6]. Guidelines for prophylactic carpal tunnel decompression are unclear, but may include cases with exacerbation of pre-existing carpal tunnel syndrome and those with compartment syndrome.

Investigations

X-Ray

Pre-operative planning in all distal radius fractures will include plain radiographs of the wrist, together with views of the remainder of the forearm and elbow. For adequate film quality, radiographs may need to be taken without plaster casts or splints. Good quality plain radiographs reveal the majority of important details necessary for planning management, and also provide baseline films for comparison during follow-up. Associated abnormalities of the distal ulna or carpal bones may require further imaging or consideration intra-operatively.

Normal Parameters

An understanding of normal distal radius anatomy is crucial for accurate injury assessment. The articular surface normally displays 10–12° of volar tilt, 22–23° of radial inclination and 11–12 mm of radial length [19, 22, 42]. Ulnar variance, the relation of the radial articular surface to the ulnar head, is ±1 mm [21, 42]. This measurement must be taken in neutral forearm rotation, as relative ulnar length alters with supination and pronation of the forearm [14, 22, 51].

Functional results are related to anatomical restora-tion [24, 53], as minor anatomical disturbances can

31 Pre-Operative Assessment in Distal Radius Fractures

significantly affect wrist mechanics. The distal radius normally accepts approximately 82% of axial load, with the remainder through the ulna via the triangular fibrocartilage complex [50]. However, in the presence of only 20° of dorsal tilt, 50% of the load is distributed through the ulna, and the radiocarpal forces shift to the dorsal scaphoid articular facet [46]. These anatomical derangements manifest in poor functional results, with malunions in more than 20° of dorsal angulation dis-playing impairment of grip strength and endurance. The wrist tolerates radial shortening poorly, with 2.5 mm of shortening increasing the loading of the dis-tal ulna from 18 to 42% of the total load [28, 50, 52] (see Table 1.1).

On the PA radiograph, radial inclination and ulnar variance should be measured with relation to a central reference point on the ulnar border of the radial articu-lar surface, to allow for changes of position in the dor-sal and volar ulnar corners in angulated fractures [42] (Fig. 1.1). The adequacy of a lateral radiograph can be assessed by the relation of the pisiform to the scaphoid. In a true lateral view, the pisiform overlaps the distal pole of the scaphoid, but in relative pronation or supi-nation this relationship is disrupted [42]. The attain-ment of a true lateral view is essential, as this has a significant effect on radial and carpal alignment mea-surements [8]. Standard PA and lateral views may be supplemented by further useful views. Allowing for the normal 22–23° radial articular inclination, a radio-graph taken with the forearm inclined 20–25° in a radial direction will show a true lateral view of the articular surface [39]. Medoff further recognized the relevance of a 10° radial inclination of the ulnar two-thirds of the articular surface, and advocates a 10° lat-eral view to profile the lunate facet [42]. Oblique PA radiographs in partial pronation and supination further

display the dorsal lunate fossa and radial styloid, respectively (Figs. 1.2 and 1.3).

Fracture Characteristics

Extra-articular fractures of the distal radius do not involve the radiocarpal or radioulnar joint surfaces; however, the importance of optimal management should not be underestimated. There still exists a potential for gross anatomical derangement, malunion and func-tional deficit. The presence of the metaphyseal com-minution and the initial displacement of the fracture aid the selection of the treatment modality due to frac-ture instability. If these fractures are displaced, the dis-tal radioulnar joint is likely to be injured.

Involvement of the articular surface is an important fracture characteristic, as incongruity of the joint surface can adversely affect outcome [29]. Patients must be counselled appropriately regarding the risk of degenera-tive arthritis [18, 29]. Knirk and Jupiter studied 43 intra-articular fractures for a mean of 6.7 years using plain radiographs, and found radiographic evidence of arthri-tis in 91% of those with residual articular incongruity, but only 11% of those who healed with a congruous articular surface [29]. Plain radiographs should be scru-tinized for fracture lines extending into the radiocarpal or radioulnar joints, and CT (computed tomography) examination undertaken if the surgeon considers it will aid in treatment. Melone proposed that the radial

Table 1.1 Radiographic criteria for acceptable healing of a distal radius fracture. (Courtesy of Graham [22], with permission)

Radiographic criterion Acceptable measurement

Radioulnar length Radial shortening <5 mm at DRUJ compared with contralateral wrist

Radial inclination Inclination on PA film ³15°

Radial tilt Sagittal tilt on lateral projection between 15° dorsal tilt and 20° volar tilt

Articular incongruity Radiocarpal articular incongruity of £2 mm

Fig. 1.1 Measurement of the radial inclination and ulnar vari-ance in relation to the central reference point on the ulnar border of the radius. This point reduces variations with excessive dorsal or volar tilt of the distal fragment

4 G. I. Bain

Fig. 1.2 Normal PA, pronated oblique and lateral radiographs

Fig. 1.3 PA, oblique and lateral radiographs showing a comminuted intra-articular fracture. The oblique view shows displacement of the dorsal ulnar corner fragment

51 Pre-Operative Assessment in Distal Radius Fractures

articular surface fractures into three predictable frag-ments, including the radial styloid, palmar medial and dorsal medial fragments [43]. In forming the lunate fossa and distal radioulnar joint, the importance of the two medial fragments for articular function is highlighted. If present, anatomical reduction of these two fragments is critical to outcome. In complex fracture fixation, their reduction early in the procedure can form a cornerstone from which other regions are reconstructed. Melone also introduced a classification with five subtypes, impor-tantly recognizing that fragment location and malrota-tion may contribute to fracture instability and inability to be reduced by closed means [43–45]. Medoff introduced additional concepts regarding articular fragmentation patterns, including the common central articular frag-ments and dorsal wall fragment [42] (Fig. 1.4). A key concept regarding articular fractures is that each articular rim fragment should have an intact radiocarpal or radi-oulnar ligamentous attachment. These ligaments not only reinforce their zones of attachment, but also con-tribute to fracture location via avulsion mechanisms, leading to the common fragmentation patterns described by Melone and Medoff (Fig. 1.5). These fracture pattern models are a useful guide in the majority of injuries. Recent work by the authors of this chapter has shown that, at the rim of the distal radius, fracture lines are most likely to propagate in the interval between ligamentous attachments. The ligaments seemingly reinforce the skeleton. However, a fracture line may be present in any location on the articular surface, particularly in high-energy comminuted injuries where high-quality imaging is required to properly define an individual fracture.

Current recommendations for fracture reduction include an intra-articular step of 2 mm or more [22, 29]; however, nil displacement is desirable in younger and highly functioning individuals [64]. Central articu-lar depressed fragments signify a need for open reduc-tion. They are unlikely to be amenable to closed treatment as there are no ligamentous attachments to these fragments to allow successful reduction by liga-mentotaxis. Despite the suitability of the volar locking plate in the majority of cases requiring internal fixation,

Fig. 1.4 Fragment classifica-tion system showing the common articular fragments. These include the radial styloid, dorsal ulnar corner, dorsal wall, volar rim and free intra-articular fragments

Fig. 1.5 Axial distal radius illustration with major radiocarpal and radioulnar ligament attachment regions. A: TFCC attach-ment to sigmoid notch. B: Radioscapholunate mesentery attach-ment. C: Extremely elastic dorsal wrist joint capsule attachment. The articular surface is most likely to fracture between ligamen-tous attachments, in regions A, B and C

6 G. I. Bain

including those with the familiar dorsal metaphyseal comminution, dorsal and dual approaches are still required for anatomical reduction in some cases. The presence of dorsal shear fragments may necessitate dorsal plating. A potential need for dorsal plate posi-tioning should be considered pre-operatively, and the patient specifically counselled regarding future plate removal and the possibility of extensor tendon irritation or rupture. In some cases of severe fracture comminu-tion, a distal radius fracture may be unreconstructable, and a bridging external fixator or primary wrist arthro-desis may be considered.

The common radial styloid fragment often includes the terminal fibres of the brachioradialis insertion [42]. This muscle acts as a significant deforming force in fractures of the distal radius, and particularly on the radial styloid fragment when present [30, 56]. In oper-ative open reductions, this tendon may need to be released or lengthened [30, 49].

Ulnar styloid fractures are a common accompani-ment to distal radial fractures, occurring in up to 70% of cases [20, 36]. Nonetheless, injuries to the distal radi-oulnar joint or triangular fibrocartilage complex can be difficult to recognize on plain radiographs, with the potential for chronic pain and instability [29, 37]. Basal ulnar styloid fractures are more likely than small avul-sion fractures near the distal tip to result in DRUJ insta-bility [37]. Whereas some authors recommend internal fixation of basal styloid fractures or splintage in the position of maximal stability, there is some evidence to suggest that these extra measures will not affect the eventual outcome. A recent large multi-centre study has concluded that the association of a basal ulna styloid fracture has no bearing on the outcome following distal radius fracture even when initially displaced more than 2 mm [60]. This study has some limitations inherent in the design, in particular that DRUJ instability was not reproducibly assessed, and therefore the conclusions may be open to challenge. Pain often prevents timely clinical testing of the DRUJ pre-operatively or in those cases treated non-operatively. However, following internal fixation of a distal radius fracture, DRUJ sta-bility should be routinely tested and documented.

Closed manipulation and repeat radiographic or fluoroscopic examination may further guide treatment. The success of reduction manoeuvers and fracture sta-bility may be judged by these methods if doubt exists, and progression to more invasive fixation performed if necessary.

Associated injuries to the DRUJ, carpal bones and ligaments, or elbow region should be defined, and an appropriate management plan devised. High-energy fractures in particular have an elevated risk of concurrent injuries to both local and remote regions of the limb.

Fracture Stability

The stability of a wrist fracture refers to its capacity to withstand displacement following manipulation into an anatomic position. Numerous factors contribute to this, including bone quality, initial fracture displace-ment, comminution and the amount of energy applied to the wrist at the time of injury. Closed manipulation and cast application is often valuable in the acute pre-sentation of grossly displaced fractures. In some cases, it may be the only treatment that is required; however, judgement should be based on the patient characteris-tics and an assessment of fracture stability.

Numerous authors have further quantified the fac-tors leading to fracture instability. Mackenney and co-workers examined factors contributing to early or late instability, dependent on the presence of fracture dis-placement at presentation. In fractures minimally dis-placed at presentation, they discovered significant risks of early or late instability with age >80 years, any form of comminution, positive ulnar variance and dor-sal angulation of 5–10° [40]. Overall, similar factors were relevant to fractures displaced at the time of pre-sentation. Assessment should be made of the radiocar-pal alignment on the lateral radiograph following reduction. Lines drawn through the long axis of the capitate and radius should cross within the carpus; otherwise there is imbalance and progressive loss of reduction, or poor functional outcome may be observed. Lafontaine also included radiocarpal intra-articular involvement and associated ulnar fracture as risk factors for instability [34] (Fig. 1.6). Furthermore, patient age greater than 60 years or the presence of 4 mm of shortening have been reported as indicative of instability [1, 47].

Medoff recognized the implication of dorsal radio-carpal instability in the presence of a dorsal wall frag-ment [38, 42]. In addition, a small series has been published recommending caution in the presence of a palmar lunate fossa fragment, which may cause volar radiocarpal instability [3] (Fig. 1.7). Careful attention should be given to these palmar or dorsal rim

71 Pre-Operative Assessment in Distal Radius Fractures

fragments and CT requested if necessary to exclude radiocarpal subluxation. These fragments will require anatomical reduction if displaced.

The extent of metaphyseal comminution is impor-tant in judging stability [17]. The radial cortex should ideally form an intact scaffolding to help maintain anatomical reduction, but comminution or poor bone quality will impair this function. Osteopenic or osteo-porotic bone not only lacks intrinsic structure but is less likely to successfully hold Kirshner wires and other forms of internal fixation. Conversely, high-energy injuries in good quality bone may have a simi-lar effect, causing marked initial displacement, severe comminution and extensive soft tissue stripping. Gross fracture displacement at the time of presentation implies a great degree of soft tissue stripping [11]. Principally, it is loss of the periosteal sleeve at the fracture site that contributes to instability. Traditionally, stable fixation of these grossly unstable injuries has been near unattainable. However, the advent of

locking plate technology has revolutionized treatment of many unstable fracture patterns in both normal and poor quality bone [48, 49].

Assessment of fracture stability is a useful tool for formulating appropriate management plans and coun-selling patients on risk of loss of reduction if closed means are chosen. Serial plain radiographs are routinely performed within 1–2 weeks following a closed manip-ulation to confirm maintenance of fracture reduction.

CT Imaging

CT is invaluable in assessing selected intra-articular fractures, where it is superior to plain radiographs [10, 23, 25, 27, 54]. Studies by Kreder and Cole both highlight the difficulty of assessment of plain radio-graphs to determining articular incongruity, with poor intra-observer and inter-observer reliability [10, 33].

Fig. 1.6 Unstable distal radius fracture, with instability features including comminution, dorsal angulation, radiocarpal articular involvement and positive ulnar variance. There is also the com-

mon avulsion fracture of the ulnar styloid tip, most likely of no consequence

8 G. I. Bain

Anatomical reduction of the distal radioulnar joint is a primary goal in any articular fracture, and CT clearly displays involvement of the radial sigmoid notch. Pruitt et al. analyzed 18 fractures pre-operatively, and showed that CT was better than plain radiographs at demonstrating involvement of the DRUJ, central artic-ular depression and fracture comminution [54]. Central articular “die punch” fragments are particularly diffi-cult to visualize on plain films and are well defined on CT. These fragments have no ligamentous attachments [7] and will not be amenable to closed reduction via ligamentotaxis (Fig. 1.8). Harness et al. revealed that three-dimensional reconstructions of CT images with

subtraction of the carpal bones can further aid in frac-ture visualization [23].

Small displaced or rotated fragments may be rele-vant to the treatment of a particular injury. For exam-ple, the presence of an ulno-palmar rim fragment can signify short radiolunate ligament avulsion and resul-tant volar carpal instability [3] (Fig. 1.4). The size and location of fracture fragments identified on axial, coro-nal and sagittal CT images thus may influence the sur-gical approach and the fixation method. Some surgeons advocate mapping around fracture fragments on pre-operative radiographs to plan a reduction. CT is more reliable for this, but the benefits must be weighed

Fig. 1.7 Plain radiographic findings in an acute wrist injury may seem relatively benign. CT better defines the injury, in this case a displaced palmar ulnar fragment with associated palmar carpal subluxation

91 Pre-Operative Assessment in Distal Radius Fractures

against the need for a higher patient radiation exposure and greater cost. A further benefit of CT is its ability to assess fracture characteristics post-operatively and without removing plaster casts.

MRI and Arthroscopy

MRI is not routinely used for distal radius fractures; however, it is effective at characterizing ligamentous and carpal injuries in cases with suspicious features on plain radiographs or CT. Richards et al. assessed 118 wrists following acute distal radius fracture, finding 46 TFCC tears, and scapholunate ligament tears in 22% of intra-articular fractures [55]. Spence et al. studied 21 intra-articular distal radius fractures with MRI, finding six scapholunate ligament tears and two TFCC tears [61]. As an alternative to MRI, intra-operative arthroscopy can assess associated soft tissue injuries [55], and may be performed “dry” in an acute injury to reduce the risk of compartment syndrome from fluid extravasation [12, 13]. Arthroscopy may also be used to aid articular reduction [4], but will not be discussed in detail in this pre-operative planning discussion. Fractures involving a split between the scaphoid and

lunate facets are associated with high rates of scapholu-nate ligament tears, which may be present in up to 45% of intra-articular fractures [55, 57, 61, 65]. Many of these ligament tears are incomplete and probably inconsequential; however, those with evidence of com-plete scapholunate ligament disruption benefit from early operative treatment [57].

Fracture Classification

Classification systems can provide a framework for the management of distal radius fractures and aid with prognostic expectations. The most commonly quoted classification is the Arbeitsgemeinschaft für Osteosyn-thesefragen (AO) system. This system divides distal radius fractures into extra-articular (type A), partial articular (type B), and complete articular (type C), with further divisions and subdivisions to encompass most possible fracture configurations. The AO system has shortcomings with poor inter-observer reliability regarding its subtypes [16, 32], and its complexity lim-its its daily use.

Most useful for daily management is the use of basic fracture description. There will rarely be confusion if

Fig. 1.8 CT of an intra-articular fracture shows excellent fragment detail for operative planning. Note particularly the depressed central articular fragment and the scapholunate dissociation

10 G. I. Bain

an injury is presented as a radial styloid fracture, rather than an AO type B1 fracture. This also allows more accurate and reproducible communication with non-orthopaedic physicians. Still in routine use are numer-ous eponymous terms, including Colles’, Smith’s and Barton’s fractures. Although helpful if used correctly, the injuries are often quite different to those originally described. To many referring doctors who infrequently treat wrist injuries, a Colles’ fracture may be used as a generic description of any distal radius fracture, and clarification of the injury features should be sought.

A number of classification schemes have been pub-lished, each with its own merits and disadvantages. The Frykman classification favourably includes the presence or absence of an ulnar styloid fracture [20], but lacks adequate detail with regards to the distal radius fracture. It thus includes severe high-energy comminuted fractures in the same group as much sim-pler low-energy injuries and is not useful in determin-ing management options or prognosis. Melone classified articular fractures into five groups and was the first to include articular fragmentation patterns [43]. Unfortunately, the Melone, Mayo, Frykman and AO classifications have all been shown to have sub-optimal inter-observer and intra-observer reliability [2].

The Fernandez classification differs from others through its description of injury mechanisms, includ-ing bending, compression, shearing and avulsion [15, 26]. Considering that treatment will often involve reversal of the initial pathological forces and subsequent maintenance of stability, the concepts con-tained in this classification can be very beneficial.

Summary

Appropriate treatment of a distal radius fracture initially requires careful consideration of patient characteristics, functional demands and soft tissue condition. Associated injuries to the ulna and carpal ligaments are common and should be sought. CT imaging is particularly valu-able in assessing fractures involving the articular sur-face. Recognition of common articular fragmentation patterns and instability features can aid treatment choice to prevent poor outcomes due to malunion or degener-ate arthritis. Advanced age, fracture comminution and displacement are key indicators of instability. Surgical treatment should ideally provide adequate reduction and

stability to allow restoration of distal radial anatomy and subsequent function.

Acknowledgement To co-authors Daniel G Mandziak, M.B.B.S., Royal Adelaide Hospital and Adam C Watts M.B.B.S., F.R.C.S.(Tr and Ortho), Modbury Public Hospital, Adelaide, Australia for their contribution to this chapter.

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13F. del Piñal et al. (eds.), Arthroscopic Management of Distal Radius Fractures, DOI: 10.1007/978-3-642-05354-2_2, © Springer-Verlag Berlin Heidelberg 2010

Introduction

Wrist arthroscopy has steadily grown from a mostly diagnostic tool to a valuable adjunctive procedure in the treatment of distal radius fractures. The ability to visualize the fracture fragments under high power magnification enables the surgeon to anatomically reduce the articular surface with minimally invasive percutaneous techniques. Many studies have demon-strated the superiority of an arthroscopic-assisted reduction of a displaced intraarticular fracture over a fluoroscopic reduction which has been shown to cor-relate with improved wrist motion and grip strength. Doi and coworkers performed a prospective study comparing 34 intraarticular distal radius fractures treated with arthroscopic reduction, pinning (ARIF), and external fixation vs. 48 fractures treated with open plate fixation (ORIF) or with pinning ± external fixation. At an average follow-up of 31 months, the ARIF group had significantly better ranges of flexion-extension, radial-ulnar deviation, and grip strength (p < 0.05). Radiographically, the ARIF group had better reduction of volar tilt, ulnar variance, and articular gap reduction [8]. Ruch et al. compared the functional and radiologic outcomes of arthroscopically-assisted (AA) percutane-ous pinning and external fixation vs. fluoroscopically-assisted (FA) pinning and external fixation of 30 patients with comminuted intraarticular distal radius fractures. Patients who underwent AA surgery had sig-nificantly improved supination compared with those who underwent FA surgery (88 vs. 73°). AA reduction

also resulted in improved wrist extension (77 vs. 69°) and wrist flexion (78 vs. 59°) [18]. The following chapter will discuss the portal placement and method-ology of wrist arthroscopy along with its application in the treatment of distal radius fractures.

Relevant Anatomy

The standard portals for wrist arthroscopy are mostly dorsal. This is in part due to the relative lack of neuro-vascular structures on the dorsum of the wrist as well as the initial emphasis on assessing the volar wrist ligaments. The dorsal portals which allow access to the radiocarpal joint are so named in relation to the ten-dons of the dorsal extensor compartments. For exam-ple, the 1–2 portal lies between the first extensor compartment tendons which include the extensor pol-licus brevis (EPB) and the abductor pollicus longus (APL), and the second extensor compartment which contains the extensor carpi radialis brevis and longus (ECRB/L). The 3–4 portal is named for the interval between the third dorsal extensor compartment which contains the extensor pollicus longus tendon (EPL) and the fourth extensor compartment which contains the extensor digitorum communis (EDC) tendons. In a similar vein, the 4–5 portal is located between the EDC and the extensor digiti minimi (EDM). The 6R portal is located on the radial side of the extensor carpi ulnaris (ECU) tendon as compared to the 6U portal which is located on the ulnar side (Fig. 2.1a–c).

The midcarpal joint is assessed through two portals, which allow triangulation of the arthroscope and the instrumentation. The midcarpal radial portal (MCR) is located 1 cm distal to the 3–4 portal and is bounded radially by the ECRB and ulnarly by the EDC. The

Portals and Methodology

David J. Slutsky

D. J. Slutsky, MD, FRCS(C) The Hand & Wrist Institute, 2808, Columbia Street, Torrance, CA 90503, USA e-mail: d-slutsky@msn.com

2

14 D. J. Slutsky

ulnar midcarpal portal (MCU) is similarly located 1–12 cm distal to the 4–5 portal and is bounded by the EDC and the EDM.

The relative safety of the portals has been studied by the way of cadaver dissection. Although some artifact is inescapable due to the displacement of neurovascular structures postmortem, this research provides some useful guidelines. In the clinical situation, distortion of the topographical anatomy due to fracture/dislocation or swelling as well as the use of intraoperative traction may increase the potential for harm; hence, a standard-ized method for establishing each portal is useful.

Dorsal Portals

Dorsal Radiocarpal Portals

Abrams and coworkers performed anatomical dissec-tions on 23 unembalmed fresh cadaver extremities and measured the distances between the standard dor-sal portals and the contiguous neurovascular structures [1]. The 1–2 portal was found to be the most perilous. The radial sensory nerve exits from under the brachio-radialis approximately 5 cm proximal to the radial

styloid and bifurcates into a major volar and a major dorsal branch at a mean distance of 4.2 cm proximal to the radial styloid [24]. Branches of the superficial radial nerve (SRN) that were radial to the portal were within a mean of 3 mm (range 1–6 mm), whereas, branches that were ulnar to the portal were at a mean of 5 mm (range 2–12 mm) (Fig. 2.2). The radial artery was found at an average of 3 mm radial to the portal (range 1–5 mm). Up to 75% of the time, there occurs either partial or complete overlap of the lateral ante-brachial cutaneous nerve (LABCN) with the SRN[13]. In an anatomical study by Steinberg et al., the LABCN was present within the anatomic snuffbox in 9 of 20

cba

Fig. 2.1 Dorsal portal anatomy. (a) Cadaver dissection of the dorsal aspect of a left wrist demonstrating the relative positions of the dorsoradial portals. EDC extensor digitorum communis; EPL extensor pollicus longus; SRN superficial radial nerve.

Lister’s tubercle = asterisk. (b) Relative positions of the dorsoul-nar portals. EDM extensor digiti minimi; DCBUN dorsal cutane-ous branch of the ulnar nerve. (c) Positions of the 6R and 6U portals (Copyright by Dr. Slutsky [23])

Fig. 2.2 Branches of the superficial radial nerve (SRN). SR1 minor dorsal branch; SR2 major dorsal branch; SR3 major pal-mar branch (Copyright by Dr. Slutsky [23])