Common, But…

A fracture of the distal radius could happen while skiing, hiking, or even house cleaning. It is one of the most common fracture sites of the upper extremity. The injury could be an unstable, intra-articular fracture with ulnar involvement, a comminuted open fracture, or a non-displaced fracture.¹ Even if it is a less complicated trauma, such as a stable extra- articular fracture, a thorough understanding of the pertinent anatomy, healing process, and potential complications is necessary to evaluate the clinical findings and institute a physical or occupational therapy program so the patient can achieve maximal function.

Grandma is in the Emergency Department

Approximately 16% of white women over age 50 will fracture their distal radius. This is in contrast to only 2% to 3% of men the same age. Most of these independent women sustain low-energy injuries, such as falling while walking. Fifty percent of them will have residual impairments, and some will lose independent function.¹ Interestingly, right handed older people tend to fracture their non-dominant distal radius more frequently.² Many have co-morbidities. For example, poor cognitive skills almost double the risk of fracture in patients over age 75. Previous fractures since age of 50 and a history of recurring falls also increase the likelihood of sustaining a distal radius fracture (DRF). Low bone mineral density is the greatest risk factor for women. Bone mineral density measures osteoporosis, which is commonly seen in post-menopausal women. About 90% of DRFs in osteoporotic women are extra-articular.¹ Although it takes the elderly longer to recover from fractures, the final clinical outcome is independent of age,^3,4 and with proper treatment, satisfactory function can be restored.

Preventing injury is not always easy. The rate of falling can be reduced by behavioral changes, such as avoiding climbing on ladders, using a tub seat, and exercising to improve balance and strength. Removing area rugs and obstacles on the floor also can prevent falls in the home.^5,6 Lifestyle modifications like eating foods rich in calcium and vitamin D and engaging in weight bearing exercises help maintain bone heath. Improving bone density is important for women with a low bone mineral density. Estrogen has been shown to decrease bone loss after menopause. Unfortunately, it increases the risk of cancer and stroke.⁷ Medications such as Fosamax (alendronate) and Boniva (ibandronate) can minimize or even reverse bone loss. In fact, there has been a statistical reduction in DRFs in post- menopausal women with low bone mineral density after taking Fosamax for three years. Additional studies are being conducted in this area of medicine.^7,8 As therapists, we could play an active role in reducing the incidence of falls by educating patients in preventative measures and encouraging them to discuss medical and nutritional options with their physicians.

The Way the Radius and Ulna Looked Before the Fracture

The distal radius has many contours designed to accommodate surrounding tendons, ligaments, and adjacent bones. The volar concave surface is a non-articular surface that is smooth at the level of the metaphysis. This is the site of attachment of the pronator quadratus. On the radial side, there is a styloid process that is covered by the abductor pollicis longus and the extensor pollicis brevis tendons, the tendons in the first dorsal compartment of the extensor tendons. Proximal to the styloid is the radius’ tubercle, the insertion site for brachioradialis. The distal side of the radius is smooth and concave. It has a faint ridge dividing it in two, where it articulates with the scaphoid and the lunate. The sigmoid notch is a concave facet on the ulnar side of the radius that articulates with the head of the ulna to form the distal radioulnar joint. The distal radioulnar joint is stabilized by a complex of ligaments and a fibrocartilage disc, known as the triangular fibrocartilage complex, and ulnocarpal ligaments.⁹ Lister’s tubercle, a prominent landmark, is on the dorsum of the radius. Just ulnar to Lister’s tubercle is the narrow groove through which the extensor pollicis longus passes on its course to the thumb’s distal phalanx. The radius is about 2 cm longer than the ulna, and the radial styloid averages about 11 mm from the distal radioulnar joint. It tilts volarly approximately 12 degrees and inclines radially about 22 degrees.^9,10

 The distal ulna does not articulate with the carpal bones. Its smooth distal surface is covered by the triangular fibrocartilage disc. There is a small, rough area near the base of the styloid process where the disc inserts. The wrist’s ulnar collateral ligament attaches to the styloid process on the ulnar side of the bone. On the dorsal surface is a groove for the extensor carpi ulnaris. The ulna articulates with the distal radius on its radial side.¹⁰ 

Describing the Break

When a patient with a DRF is initially evaluated in the emergency department, the physician must decide whether the fracture can be treated conservatively with reduction and casting or if surgical intervention is required to achieve and maintain anatomical reduction. This decision is based on the fracture pattern, degree of fracture fragment displacement, and stability of the fracture. Age, lifestyle, and job requirements are also considered. Whether the patient has support at home ideally plays a role in determining if surgical treatment is appropriate.¹¹

There are a variety of classification systems, most of which have gone through multiple evolutions. They have been developed to consistently and reliably describe the nature of the fracture and to assist in delineating treatment options. A well-structured system will ultimately result in the same conclusions being reached by different evaluators. The injury can be named for the fracture patterns, clinical appearance, or who described it, such as a Colle’s fracture.¹² The American Orthopedic system has excellent reliability. Its condensed form has three fracture types: extra-articular, intra-articular with part of the metaphysis intact, and intra-articular with complete disruption of the metaphysis.¹² Generally, non-displaced extra-articular fractures are amenable to closed reduction and casting.¹³ Fractures that do not maintain good bony alignment with plaster immobilization, such as intra- articular or comminuted fractures, require surgical intervention. Surgeons use percutaneous pins, tension band wires, screws, external fixators, and most commonly, plate fixation to stabilize the more complicated fractures.⁹

Healing in Three Stages

A fractured bone heals by regenerating new bone, not scar tissue. This can be accomplished via primary or secondary healing. Primary healing requires surgical wiring, plating, or screwing so the bone ends can compress. There is no gap between the fragments, and the fracture ends remain immobile. This establishes the necessary environment for osteoclasts to begin the revascularization process almost immediately, and for the osteoblasts to begin forming new bone. When a bone heals by primary healing, the immature bone is developed without a callus. The fracture strength is initially dependent on the implant strength. It is imperative to remember that though there is rapid bony union, the tensile strength increases as calcification and remodeling of the tissues along the fracture’s stress lines takes place. In other words, it will still take five to six weeks for the bone to heal sufficiently to withstand any stress.^14,15

 If the fracture is treated by closed reduction, or with semi rigid fixation such as Kirschner wires or an external fixator, it will heal through secondary healing. These types of fixations align the fracture ends, but they do not compress them. As a result, some movement does occur at the fracture site.¹⁴ Like soft tissue, bone that heals by secondary healing progresses through three distinct but overlapping phases. Immediately after injury, the inflammatory stage begins with the formation of a hematoma. An inflammatory response occurs, causing vasodilation, exudation of plasma, and inflammatory cell migration to the injury site. Macrophages debride the bone ends’ necrotic tissue, and cell differentiation is initiated. Immature cells differentiate into cell types necessary for healing, such as blood vessels and connective tissue. The fracture site is very fragile at this point.^14,15

 Within the first or second week after the fracture, the repair stage begins. The small amount of motion at the fracture site is beneficial for healing; too much results in a non-union.¹⁴ As a result of the small movement, the hematoma is replaced with granular tissue to form a soft callus. The callus acts as a bridge between the fracture ends and provides some stability during the healing process.^14,15 Although a clinical union is present within the first three weeks, the bone and connective tissues are poorly organized. They cannot withstand any significant force. Through ossification, the soft cartilaginous callus is gradually converted to a bony, or hard, callus. This ossification begins at the periphery of the callus and progresses towards the center.¹⁵ Seen on X-ray within 12 to 16 weeks, this callus strengthens the bone. It is not as strong as the radius’s uninjured bone, though.¹⁴

During the remodeling phase, which can last for several months, and even years, the bone will remodel in response to the demands placed on it. Bone is deposited in areas of high stress and absorbed in areas of low stress. The callus recedes as bone tissue is aligned along the lines of force. Eventually, the fracture site’s strength will return to normal, and the fracture line cannot be detected on X-ray.^14,15  

Rehabilitating Grandma

Normal active supination and pronation is each 90 degrees; active wrist flexion is 80 degrees, and extension is 70 degrees; radial deviation is 20 degrees, and ulnar deviation is 30 degrees.¹⁶ Following a fracture, the goal is to achieve range of motion that is functional and pain-free. There is a wide discrepancy in the literature, but Ryer reported that ADLs can be accomplished with 40 degrees each of flexion and extension, a total range of 40 degrees for radial and ulnar deviation, and 50 degrees each of forearm supination and pronation.¹⁷

Just as a DRF can be a relatively simple extra-articular fracture or a complex intra-articular injury involving extensive soft tissue injury, the rehabilitation can be relatively straightforward or complex. A thorough history and evaluation is mandatory to establish a treatment program based on the stages of healing and the patient’s lifestyle. The following is a suggested protocol for extra-articular DRFs treated with closed reduction and cast immobilization. Like the healing phases, the treatment phases are non-discrete and overlap.¹⁵ This protocol needs to be modified according to the patient’s pre-morbid status, response to therapy, and functional demands.¹³ For example, a hand with arthritis would probably require more gentle AROM exercises for the digits to regain and maintain mobility than one with healthy joints.

Modalities

To help decrease pain and stiffness, thermal modalities, such as moist hot packs and paraffin, can be used if the inflammation is under control.²² If inflammation or edema is hindering progress, elevation, massage, compression, ice,¹⁹ or high-volt electrical stimulation²³ can help be useful.

Splints

Splints can serve a variety of purposes during fracture recovery and rehabilitation. As previously stated, in the early phases they can help rest inflamed tissue and provide needed support for the weak wrist. When used appropriately and correctly, splints can also help improve motion. If pain and edema are under control, digital splinting can begin even while the wrist is still casted. Dynamic slings for metacarpal phalangeal flexion or flexion straps that gently hold the interphalangeal joints in flexion can improve composite fisting. Static or static progressive splinting through individual finger trough splints or a hand-resting splint may help interphalangeal extension.^13,20

If functional range of motion of the digits, wrist, or forearm has not been achieved by around the tenth week, static progressive or dynamic splints might be warranted. These devices improve motion by gradually lengthening shortened tissue.¹⁷ Attempts at rapid lengthening through vigorous passive range of motion may cause microscopic tearing, bleeding, and inflammation.¹³ Instead, the tissues should be stretched slowly, using a low force over a long period of time. This allows the collagen fibers in the surrounding soft tissue to reorganize and lengthen during the remodeling phase of healing. The shortened, disorganized collagen is reabsorbed as the new collagen is laid down in the lengthened position.¹³ If the splinting program is done correctly, range of motion is improved without inflammation or pain. There are many prefabricated splints and custom splint designs that effectively increase a joint’s mobility. However, they require a therapist who is experienced in splinting to fabricate, apply, and monitor. Though the splint options are too numerous to describe in detail, they are certainly worth investigating.

What Can Go Wrong

Even a seemingly simple extra-articular DRF fracture can disrupt the anatomical relationship between the ulna and the radius. Frequently, the radius’ volar tilt reverses and becomes a dorsal angulation. The bone subsequently shortens, resulting in a relatively long ulna.^24,25 Overall, the long-term outcome is related to the final alignment and length of the radius.³ Dorsal angulation with concomitant radial shortening tends to be more pronounced in osteoporotic bones.²⁴ As little as 4% loss of length of the radius can result in poor functional outcome due to pain and stiffness.²⁵ Typically, there is a loss of forearm rotation and impingement of the ulna on the proximal row of the carpus.^3,24,25 Even a decade after the injury, the most frequent complaint reported is pain or discomfort with heavier activities.³

 In addition to the bony insult, DRFs may be accompanied by injury to the surrounding carpal ligaments, interosseous ligaments, extrinsic tendons, and the triangular fibrocartilage complex.²⁰ More than 50% of extra-articular DRFs have triangular fibrocartilage complex lesions, which can cause ulnar-sided pain with simple activities such as twisting a door handle and pouring a drink.²⁶

Neck and especially shoulder and elbow stiffness can persist after the cast is removed. When the wrist and fingers are weak and stiff, frequently the arm is not used for functional activities. In addition, one is inclined to hold the arm in a protected, guarded position, which will further encourage immobility of the proximal joints. Active and passive range of motion exercises should be reinforced early to prevent such complications as frozen shoulder or persistent neck or elbow stiffness.²⁰

Extensor tendons, especially the extensor pollicus longus, are vulnerable to rupture. It is suspected that there is attrition of the extensor pollicus longus tendon as it is held over the enlarging healing bone. Rupture becomes evident when the patient is unable to actively extend the thumb’s interphalangeal joint. Surgical intervention is the only definitive solution.²⁷

Both flexor and extensor tendons may become adhered to surrounding tissues during healing. Tendon gliding, active range of motion exercises to the wrist and digits, and edema control can help minimize these adhesions. Tendon gliding exercises are essentially a series of four exercises: extension of all the digital joints, flexion of just the interphalangeal joints, flexion of just the metacarpal phalangeal and proximal interphalangeal joints, and flexion of all the joints to make a fist.¹³

The median nerve is quite susceptible to injury as it crosses the wrist through the carpal canal.²⁷ Acute carpal tunnel syndrome, comprising 22% of all complications of DRFs,²⁸ is seen most frequently with comminuted or dislocated fractures. However, symptoms can develop as a direct result of the injury or while the patient is casted.²⁷ After cast removal, splinting the wrist in a neutral position, especially at night, often alleviates the symptoms.²⁹ Edema management, gentle finger active range of motion, and tendon gliding exercises should be continued. Carpal tunnel syndrome that is recalcitrant to conservative treatment may require surgical release.²⁹

Edema is part of almost every fracture recovery. However, to achieve full active range of motion, it is necessary to control the amount and duration of the edema. Edema in the digits and hand will impede finger motion through obstruction and restriction of normal tendon gliding. In addition, more strength is required to move an edematous digit.¹³ If the edema becomes chronic, it results in increased pain and interstitial scarring, which will further limit motion.¹⁹

Although not always a direct result of the fracture alignment, tendonitis can develop later in the treatment program. It is especially evident after the introduction of strengthening exercises and increased use of the upper extremity in ADLs. Tendons in the first dorsal compartment, the abductor pollicus longus and the extensor pollicus brevis, as well as the extensor carpi ulnaris, are frequently problematic.²⁷ Modification or elimination of the inciting exercises and activities should alleviate the symptoms. Modalities and splinting might be needed to expedite the resolution of pain, or the physician may need to inject the inflamed structure with a steroid.²⁷ If the patient is having difficulty grasping objects despite having sufficient range of motion and strength, it is possible that the digital extensors are being recruited to assist the weak wrist extensors; that is, the patient is extending the fingers and wrist simultaneously. This abnormal pattern makes it difficult or impossible to pick up objects and is contrary to the normal synergistic wrist extension with digital flexion.^13,30 The normal tenodesis can be reinforced if the patient grasps a round, light object (like a PVC pipe) while performing wrist extension exercises. The metacarpal phalangeals must remain flexed during this activity in order to restore a normal synergy between the flexors and extensors.

The therapist should be concerned if a complex of symptoms develops. This can include, but is not limited to, persistent edema, stiffness, and pain. These findings, coupled with trophic changes such as increased sweating, brittle nails, and shiny or mottled skin, may be indicative of regional complex pain syndrome.²⁰ An intensive rehabilitation program that is beyond the scope of this article would be necessary.

Life After the Break

A stable extra-articular distal radius fracture, a common fracture in the upper extremity, can often be treated with closed reduction and casting.¹³ However, the therapist should not become complacent with this seemingly straightforward diagnosis. During the treatment, it is important for the therapist to continually assess and modify the rehabilitation program since complications may develop as early as the first healing phase. Subtle anatomic changes that alter the forces across the wrist and distal radioulnar joint might predispose the patient to complications such as ulnar sided wrist pain.^24,25 Vigilant attention to the signs of regional complex pain syndrome, carpal tunnel syndrome, and tendonitis should continue while the patient progresses through rehabilitation based on the three phases of bone healing. Early initiation of therapy, and careful progression of exercises with close attention to inflammation and pain, helps guide the patient through the healing process and restoration of function.¹⁴