Distal radius fractures in the osteoporotic patient should be patient specific

Introduction

As the elderly population continues to grow, osteoporotic distal forearm fractures are becoming increasingly common. The surgical outcome is often less than satisfactory because of the difficulty in obtaining reliable fixation in mechanically weak bone. This may result in wrist deformity and dysfunction. This Round Table discussion will focus on the latest advances in surgical treatment including minimally invasive techniques and plates with locking screws. Fixation augmentation techniques such as implants coated with hydroxyapatite, calcium phosphate cements and other biologics will also be discussed. Ultimately the challenge lies in managing not only these fractures that are a consequence of weak bone, but considerations must be also given to co-morbidity, which is often high in this patient population and a multidisciplinary approach can be the key to help the patient regain former function and activity levels.

These fractures also offer a tremendous opportunity to diagnose the osteoporotic disease. Furthermore, an orthopedic team dedicated to direct patient education on osteoporosis, followed by active supplements or pharmacotherapy has also been shown to improve patient outcomes and we should be sensitive to the nature of these care pathways. The Osteoporotic Fracture Campaign, which sits under the umbrella of the International Society for Fracture Repair, has been dedicated to the burning issues surrounding osteoporotic fractures including the integration of such “coordinator-based” fracture prevention programs within the hospital setting to identify osteoporotic patients which has been shown to reduce the risk of subsequent fractures.

Amy Hoang-Kim, MSC
Moderator

Amy Hoang-Kim, MSC: Dr. Ladd, what degree of deformity is generally acceptable in general and specific terms to the elderly population?

Amy L. Ladd, MD: With our expanding elderly population, many of whom lead an active lifestyle, we have greater experience with what fractures do well with minimal intervention. Surgical outcome may be unsatisfactory because of the difficulty in obtaining reliable fixation in mechanically weak bone. Some low-demand patients may accept wrist deformity and some may also accept degrees of dysfunction. Even in the face of optimal wrist alignment — with or without surgery — functional return may be independent of alignment or difficult to regain.

As practicing orthopedic surgeons, we know that many of these fractures occur in the elderly low-demand individual, often with impaired cognitive function. These individuals do not require a “perfect anatomic” reduction, or textbook anatomy upon union. They will generally function well, with minimal complaints even with a malunited fracture of the distal radius.

These same individuals will not do well with surgery, no matter how minimal. There is the potential of severe consequences to hospitalization, displacement from familiar surroundings, anesthesia, sedation and/or analgesia and the techniques themselves. Thus patient selection is of paramount importance in deciding on the role of conservative vs. surgical management.

I tend to think of patients with osteopenic fractures of the distal radius in three wide categories in terms of decision-making. The patient who will always have conservative management is the nursing-home-type with cognitive impairment who is bedridden or has poor ambulation and low functional demand. The patient who may have conservative management is the elderly, but relatively independent patient, who lives in the community, is independent for most of self care and household upkeep and who has a mildly displaced fracture that can be reasonably predicted to heal with acceptable deformity. The patient who will rarely have conservative management as the only option is the higher demand, independent patient who lives independently, has higher functional demands with leisure activity, sport and/or employment, and has severe fracture deformity, comminution or redisplacement.

Hoang-Kim: What present techniques are available for minimizing deformity with little or no surgical intervention?

Ladd: Many fractures can be reduced under regional block, conscious sedation or hematoma block into a reasonable alignment. This reduction may be maintained with a proper protocol of splinting, follow-up, repeat manipulation and casting.

What constitutes an acceptable reduction and ultimate position of healing is often patient-dependent. This applies particularly to the elderly population with osteopenia. A recent publication by Wilcke, Abbaszadegan and Adolphson confirms the relationship between poorer patient outcomes, as measured by DASH score and radiographic parameters of malunion — 2 mm or greater radial shortening, dorsal angulation greater than 15°, and radial angulation.

Hoang-Kim: What are the advantages and disadvantages of internal fixation vs. more “traditional” means?

Ladd: The advantages include:

• anatomic reduction roughly parallels restoration of function, as architect Louis Henry Sullivan said, “Form Ever Follows Function;”
• ability to address cortical and cancellous bone defects;
• early fixation provides early stability and early functional return (everybody with a plate in the past 10 years);
• patients demand early rehabilitation;
• our aging population is more active;
• it is potentially cost effective (but not borne by health carriers, only to patient thus far).

The disadvantages are:

• the (mis) interpretation of Colles: “They all do well;”
• better external fixators today;
• no uniformity to suggest internal fixation is superior according to the Cochrane database;
• functional outcome acceptable with external fixation;
• complications;
• osteoporosis confounds treatment and complications with internal fixation equipment and operative costs borne by health carriers and patient; and
• 10º were each significantly associated with a poorer DASH score, reduced grip strength, extension, and ulnar deviation also correlated with a poorer DASH score.

Della Santa and colleagues confirmed that with time, the patient adapts to the deformity and the extent of the deformity no longer correlates with the outcomes of function and pain.

McQueen and Beumer have found a lack of benefit to closed reduction in the old and frail individual. In 53 of 60 patients with distal radius fractures treated by closed reduction, the reduction was subsequently lost with no correlation between initial displacement, fracture classification and final radiographic appearance. They concluded that reduction of fractures of the distal radius is of minimal value in the very old and frail, dependent or demented patient.

Hoang-Kim: What are the downsides of specific internal fixation systems?

Ladd: The disadvantages of dorsal plating are: wrist stiffness; tendon irritation; wound and hardware complications; it is fragment specific and technically demanding; and it is difficult to use with osteoporosis.

Disadvantages of volar plating include: it is system specific; fiddle factor; hardware fixation; and self-tapping screws.

Hoang-Kim: Dr. Jupiter, is internal fixation the new currency of treatment?

Jesse B. Jupiter, MD: The “gold standard” is a quasi-standard and since 1978 gold is a commodity, not a basis of currency. Likewise, internal fixation as an enhanced distal radius fracture treatment is also not an absolute. So don’t throw out the plaster, external fixator or Rush rods.

Hoang-Kim: Could you compare the critical and biomechanical features to the rationale for achieving angular stable fixation?

Jupiter: Critical features of angular stability, in general, include: stability that is not achieved by the creation of friction between the plate and bone as in traditional screw fixation, which depends upon good-quality bone, rather by mechanical bridging of the bone and load-bearing that occurs through the locked screw-plate construct; and locking-head screws that do not rely on the bone thread for purchase and prevent loosening within the implant.

The biomechanical features of volar plate fixation include the fact that studies have emphasized the need for placement of the distal most screws or pegs just beneath the subchondral bone of the articular surface to achieve maximum benefit of volar fixed angle plates.

The rationale for volar plate fixation especially for unstable Colles’ fractures includes: an ease of anatomic reduction due to the volar cortex being less comminuted than the dorsal side; fewer problems with overlying soft tissues; the palmar cortex is stronger and flatter than dorsum; an early return to hand and independent upper limb function; a diminished need for follow-up visits and therapy; and a decreased risk of late malunion.

The potential cost savings remain to be evaluated.

Hoang-Kim: What is the current evidence for volar locking plates and what complications are associated with this technique?

Jupiter: Existing level 1 evidence in randomized prospective studies is inconclusive; however, they have not looked carefully at volar locked plating. In the current literature, internal fixation yields radiographic results and 2 year clinical results comparable with augmented external fixation.

In terms of complications, although volar locking plates may limit tendon irritation, they have not eliminated them. Irritation and rupture of the flexor pollicis longus (FPL), flexor carpi radialis (FCR) and even the extensor pollicis longus (EPL) from prominent screw tips have been reported.

Other complications include contracture from ischemia of the pronator quadratus and neurologic complications.

Hoang-Kim: Prof. Moroni, what are fixation augmentation techniques?

Prof. Antonio Moroni: Fixation augmentation techniques (FATs) can be defined as surgical procedures aimed at increasing implant stability. Our classification of fixation augmentation techniques include augmentation with polymethylmethacrylate, bone grafts, bone graft substitutes, calcium phosphate cements, coatings, modified implants, pharmaceuticals and combined FATs.

When managing fragility fractures, the diagnosis of osteoporosis is the first hurdle that the orthopedic surgeon encounters. Knowing a patient’s bone quality prior to surgery would be useful not only for the administration of the correct medical therapy, which is effective for secondary fracture prevention, but also for selecting the correct surgical treatment, including the use of FATs.

Hoang-Kim: When and why should FATs be used?

Moroni: FATs are indicated for use in patients who have suffered a fracture and whose bone is deemed osteoporotic through DXA with a bone mineral density T-Score less than -2.5 SD. Fractures which can be treated include the unstable, those which re-displace after conservative treatment and surgically treated fractures with poor screw purchase and/or large metaphyseal defects.

FATs are surgical procedures which aim to increase implant stability by offering structural support, improved fixture and fracture stability. In addition, they allow for early recovery and lead to both reduced complications and morbidity.

Hoang-Kim: Why do we need Modified Implants?

Moroni: As the majority of the available implants are designed for fixation of normal bone, we need modified implants specifically designed for osteoporotic bone fixation.

For more information:

• Amy Hoang-Kim, MSC, can be reached at the International Society for Fracture Repair, Rizzoli Orthopaedic Institute, Via GC Pupilli 1, 40136 Bologna, Italy; 39 051 636 6581; e-mail: isfr.fractures@gmail.com.
• Jesse B. Jupiter, MD, can be reached at Yawkey Center, 55 Fruit St., Suite 2011, Boston, MA 02114; 617-726-5100; e-mail: JJupiter1@partners.org.
• Amy L. Ladd, MD, can be reached at Robert A. Chase Hand & Upper Limb Center, 900 Welch Road, Suite 15, Palo Alto, CA 94304; 650-723-6796; e-mail: aladd@stanford.edu.
• Prof. Antonio Moroni can be reached at the Rizzoli Institute, 39-051-6366581; e-mail: a.moroni@ior.it.