Fracture geometry in distal radius as a predictor of concomitant injuries: proposing a ‘metaphyseal danger zone sign'

Bhaskar Borgohain¹, Praveen Tittal²

1. Department of Orthopaedics & Trauma,
North-Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, (NEIGRIHMS) Shillong, India.

2. Department of orthopaedics,
Maulana Azad Medical College, New Delhi

Address for Correspondence:
Bhaskar Borgohain
Asst. Professor and in-charge,
Department of Orthopaedics & Trauma,
North-Eastern Indira Gandhi Regional Institute of Health and Medical Sciences, (NEIGRIHMS) Shillong, India.Pin: 793018.

Abstract:

Background: Analysis of fracture pattern reveals the amount of energy imparted to the extremity and alerts the surgeons to higher risk pattern of injury. Comminuted fractures occur when the deforming force is a combination of compression, bending and torsion usually signifying a high energy injury in non-osteoporotic bone and a high likelihood of severe associated loco-regional soft tissue injury. Method: The authors present nine consecutive cases of high energy distal radius fractures in relatively younger patients, which were associated with severe comminution with or without an open wound in the metaphyseal area. Results: These cases of distal radius fractures were roughly falling into the AO-ASIF type C fractures or Fernandez type V fractures that signify high energy injuries. All these cases were associated with other significant skeletal or non-skeletal injuries; either loco-regional or remote. Conclusion: The author propounds that severe comminution in the metaphyseal or metadiaphyseal area in distal radius fractures in relatively younger individuals is an independent risk factor for associated injuries.

J.Orthopaedics 2010;7(2)e10

Keywords:

Fracture geometry; distal radius; concomitant injuries

Introduction:
 

Analysis of fracture pattern reveals the amount of energy imparted to the extremity and alerts the surgeons to higher risk pattern of injury ¹. Comminuted fractures occur when the deforming force is a combination of compression, bending and torsion ². Comminution of bone usually signifies that there is severe associated loco-regional soft tissue injury. In osteopenic bone however, comminution may result from low energy trauma and less soft tissue injury ³.  The mechanics of the fall plays important role in whether a fracture will occur and which bone will fracture. The orientation of the fall and location of the impact determine the type of fracture, and whether a fracture occurs depends on the energy of the fall (distance to impact and weight of the moving parts) and how much of that energy is absorbed by protective responses, the impact surface and soft tissues overerlying the bone ⁴. Bones break when the forces applied to them exceed their strength. The direction of impact is as important as that of the amount of force itself.⁵

It is difficult to know how much energy is absorbed by protective responses, the impact surface and soft tissues over the bone (covering) before the fracture happens. We feel that due to protective responses that attempts to prevent vital organ from injuries; the upper limbs & the body move in unaccustomed directions or positions and when the bone finally gives way (fractures) that is the end of protection, so far provided by the upper limb before loss of weight bearing/transmitting ability of the limb. At this very point of failure the same protective process risks injury to other bones and organs. From a series of cases presenting to the casualty department, we propose that specific fracture geometry of distal radius in younger individual not only predicts energy imparted on the tissue but also may predict existence of associated loco-regional and even remote injuries.
Materials and Methods:

The Case series

These cases were noted and recorded over two and a half year period in a tertiary care hospital.

@ Extradural haematoma

 $ Needing tooth extraction

 *** With minimum fluid in peritoneum that responded to conservative treatment.

The first two cases need elaboration. Case no. 1, was a neglected and heavily contaminated open fracture of distal radius in 45 year old village lady who fell down from a tree (Fig 1.) She had a contusion in lower arm which was treated so far as soft tissue injury. A second fracture was a grossly displaced ipsilateral surgical neck of humerus proved in X-ray after admission (Fig 2).

Figure 1: Case no.1 with metaphyseal extension of fracture line with gross displacement.

In Case no. 2, this deaf and dumb patient met road side accident. She had a fracture with unusual comminution (Fig 3). She was conscious and apparently there were no elements of other associated injury as per history from her attendants and also on examination. The fracture was stabilized by external fixator under local anaesthesia. Immediate postoperative condition was uneventful, but after 4 hours she became unconscious and had a cardiac arrest. The possibility of cardiac contusion, pericardial temponade, head injury or major visceral injury couldn’t be ruled out since autopsy was denied by relatives.

Figure 2: Case no.1 showing the concomitant “missed” proximal surgical neck humerus fracture

Figure 3: Unusual fracture line in metaphysic in a young adult that doesn’t precisely fall into any common classification

Figure 4: Another case where comminution is not extensive but fracture line running into high metaphysis.

Discussion :

These consecutive nine cases of distal radius fractures were associated with extension of comminution in the high metaphyseal area with or without comminution in the epiphyseal area. The metaphyseal extension of fracture line was not always seen in AP view but may be seen in lateral/oblique view radiograph only. Osteoporosis was not radiologically apparent in any case. All these cases were associated with other significant skeletal or non-skeletal injuries. These fractures were roughly falling into the type C fractures (especially C3 Type) in AO-ASIF and in Universal classification of Sarmiento (Fernandez type V fractures) and they signify high energy injuries.

From this series of cases we propose that fracture geometry of distal radius in younger individual predicts associated loco-regional or remote injuries. Our thinking and observation are based on the fact that effective protective reflexes cushion the impact of a fall in active individuals. Isolated fractures of distal radius are classically seen in osteoporotic (but fit) individuals. But fracture of distal end radius with associated ipsilateral limb injuries are increasingly found  in young active adult partly due to higher incidence of high energy trauma and increased participation in sports and similar outdoor activities ⁶. Younger individuals are usually non-osteoporosis and injuries are high energy type.  In elderly, the effective protective reflexes to cushion the impact of a fall are obtunded corresponding to their age and that is why the incidence of hip fractures are more common than distal radius fractures in elderly, which is attributed to increased frailty and decreased protective response (e.g. rapid reflexive elbow extension) during a tendency to fall ⁶.

Theoretically, the longer the length of metaphyseal comminution, greater is the likelihood of higher energy and higher protective resistance imparted by the bone of the injured individual and greater is the likelihood of impact to the surface of collision at the end point of failure (fracture). Similarly the viscera and limbs are also likely to get injured at the same time due to the magnitude of trauma and proximity to the direction of force (“line of fire”). The AO-ASIF classification of DER fractures appreciates the extent or length of metaphyseal comminution though they recognize articular comminution in more details since it is more important for DRUJ.

Though many associated injuries in distal radius fractures are well-described in the literature namely injury to the DRUJ, triangular fibro cartilage (TFCC), carpal & carpal ligament injuries, median nerve injury, radial head fracture etc ^7-10; no mention is found in these literature about remote injuries that we have noticed in our cases. The degree of articular comminution has no correlation with incidence of local injuries like TFCC injury ¹⁰. It is well known that orthopedic injuries can mask the presence of life-threatening visceral injuries ¹¹. An open fracture is also known to dramatize clinical presentation and lead to missed concomitant injuries.

Associated injuries are important in treatment and for rehabilitation. We couldn’t find any literature mentioning remote injuries in distal radius fractures. Scapular fractures are associated with chest injuries, clavicle fractures, rib fractures, tibial fractures, spleen & liver injuries ¹². But femoral fractures on the other hand are reportedly associated with other life-threatening injuries ¹¹.

Figure 5: The proposed metaphyseal danger zone sign. The dark line depicting the fracture progression line. (DRUJ: Distal Radio-ulnar Joint.)

Based on these considerations, we propose that metaphyseal comminution and extension of fracture line approximately 3 cm beyond the DRUJ may suggest possibility of another unsuspected/ occult injury; remote or loco-regional. Therefore in young patients this area may be called “Metaphyseal danger zone” (Fig.5). If this finding is present we should actively look for another missed injury. This may be especially true in patients who are non-cooperative or who have altered sensorium due to alcohol, drugs or head injuries with a wrist radiograph showing such fractures or if there is an open wound.  Statistical analysis in a large number of randomly selected cases is needed to further this observational analysis.

Reference :

1. Claiborne A. Christian In: General principle of fracture treatment. Canale S.Terry, Editor. Campbell’s Operative Orthopaedics. 9th edition, St.Louis: Mosby; 1998:1994

2. Claiborne A. Christian In: General principle of fracture treatment. Canale S.Terry, Editor. Campbell’s Operative Orthopaedics. 9th edition, St.Louis: Mosby; 1998:2004-2006

3. Joseph A. Buckwalter, Thomas A.Einhorn, J.L.Marsh In: Bone and joint healing. Robert W. Bucholz, James D. Heckman, Charles Court Brown et al Editors. Rockwood and Green’s fractures in adult. 6th edition, Lippincott Williams & Wilkins; 2006: 304

4. S. R. Cummings, M. C. Nevitt and the Study of Osteoporotic Fractures Research Group.  Non-skeletal determinants of fractures: the potential importance of the mechanics of falls. Osteoporosis international. Vol 4, supplement 1, Jan, 1994: 2S67-S70

5. Allan F. Tencer In: Biomechanics of fixation and fractures. Robert W. Bucholz, James D. Heckman, Charles Court-Brown et al Editors. Rockwood and Green’s fractures in adult. 6th edition, Lippincott Williams & Wilkins; 2006: 15

6. Prommersberger KJ, Frohner S, Schoonhoven J. Van, Schmitt R. In: Trauma of the distal forearm. Rainer Schmitt, Ulrich Lanz editors. Diagnostic imaging of hand. 3rd edition, Stuttgart-Newyork. Thieme 2008:182

7. Prommersberger KJ, Thomas Pillukat In: Distal radius fractures. David C. Ring, Mark S Cohen, Editors. Fractures of the hand and wrist. First edition, Informa Healthcare 2007: 163-165

8. R. Jay French In: Fractures and dislocations of the wrist. Mark R. Brinker Editor. Review of orthopaedic trauma. W.B.Saunders, Philadelphia 2001:277-281

9. Harry B. Skinner, Edward Diao, Richard Gosselin, David Lowenberg In: Musculoskeletal Trauma Surgery. Harry B. Skinner Editor. Current Diagnosis and Treatment in Orthopedics. Lange Medical Books/Mcgraw-Hill. 2^nd International Edition 2000: 74-82

10. Bombaci H, Polat A, Deniz G, Akinci O. The value of plain X-rays in predicting TFCC injury after distal radial fractures. J Hand Surg Eur Vol. 2008 Jun;33(3):322-6.

11. Adili Anthony Peng, Bhandari Mohit, Lachowski Richard J.et al .Organ injuries associated with femoral fractures: Implications for severity of injury in motor vehicle collisions. The Journal of Trauma: Injury, Infection, and Critical Care: 46(3)1999: 386-391

12. Weening Brad, Walton Christine; Cole Peter A.; Alanezi Khaled; Hanson Beate P.; Bhandari, Mohit. Lower mortality in patients with scapular fractures. The Journal of Trauma: Injury, Infection, and Critical Care: Volume 59(6) 2005:1477-1481

This is a peer reviewed paper 

Please cite as: Bhaskar Borgohain: Fracture geometry in distal radius as a predictor of concomitant injuries: proposing a ‘metaphyseal danger zone sign'

J.Orthopaedics 2010;7(2)e10

URL: http://www.jortho.org/2010/7/2/e10

ANNOUNCEMENTS

Arthrocon 2011


Refresher Course in Hip Arthroplasty

13th March,  2011

At Malabar Palace,
Calicut, Kerala, India

Download Registration Form

For Details
Dr Anwar Marthya,
Ph:+91 9961303044

E-Mail:
anwarmh@gmail.com

Powered by
VirtualMedOnline