♦ Proximal phalanx unicondylar and spiral fractures most unstable
♦ If axially stable can be considered for non-operative treatment
♦ Kirschner wires offer stability without excessive soft tissue dissection
♦ Ring and little finger metacarpal flexion deformity is well tolerated, but this is not the case for the radial metacarpals
♦ Displaced proximal and middle phalanx fractures are a common cause of stiffness
♦ Displaced condylar fractures are usually best reduced and fixed.
Metacarpal and phalangeal fractures have a combined incidence of approximately 380 per 100 000 per year and are most common in 10- to 39-year-old males. They are frequently caused by sporting injuries or fights. Little finger metacarpal fractures account for 30% of all metacarpal and phalangeal fractures.
There are a variety of classifications systems which describe the site and pattern of the fracture, all of which have advantages and disadvantages. Whatever classification system is used it is important to classify fractures according to their stability.
Stable fractures are those which present in acceptable alignment and will not displace into unacceptable alignment if the hand is left free and mobilized. Thus most undisplaced fractures and most displaced little finger metacarpal neck fractures are stable. There are two subtypes of unstable fractures. The first includes fractures which present in acceptable alignment though are at risk of displacing into unacceptable alignment if mobilized. Undisplaced unicondylar and spiral fractures of the proximal phalanx are examples of this type. The second subtype includes all displaced fractures which present in unacceptable alignment and require reduction, after which they must be stabilized (splinted or internally fixed) in order to prevent redisplacement. Virtually all displaced fractures which need to be reduced are unstable, and for these it is also important to consider their likely axial stability after fracture reduction.
Axial stability describes a fracture’s ability to oppose the constant tension in the digit’s flexor and extensor tendons which attempt to shorten the fracture: transverse fractures have good axial stability while long oblique fractures have poor axial stability. The axial stability of a fracture, once reduced, is one factor which determines its suitability for non-operative treatment. Fracture stability should be viewed as a spectrum with absolute stability (undisplaced transverse third metacarpal fracture) at one extreme and absolute instability (severely comminuted open proximal phalangeal fracture with bone loss) at the other.
The patient as well as the fracture must be assessed. Hand dominance, employment, and recreational activities, as well as ability to comply with the proposed treatment, must all be considered.
The mechanism and time of injury should always be ascertained. Twisting injuries are likely to cause fractures with rotational deformity and fifth metacarpal neck fractures are much more serious if there is a dorsal wound which was caused by a tooth (punching someone in the face). For open fractures it is important to determine the environment in which the injury was sustained (farmyard or clean environment).
The whole hand must be examined for swelling and bony tenderness so as not to miss multiple injuries (Figure 12.28.1), and skin sensation and perfusion distal to the fracture should also be examined, especially in crush injuries. Alignment should be carefully assessed though significant amounts of radial/ulnar and dorsal/palmar angulation can be masked by soft tissue swelling. It is of utmost importance to look for rotational deformities as these are poorly tolerated in the fingers and usually indiscernible on radiographs. Although obvious if the patient can make a fist, most with fresh fractures cannot and rotational deformity is best assessed by examining the alignment of the fingernails with the fingers extended (Figure 12.28.2).
Radiographs should be considered as a continuation of the clinical evaluation. Rather than simply requesting radiographs of the injured finger (or worse still the injured hand) one should request radiographs centred on the area of clinical tenderness where the fracture is suspected. The standard radiographic views for individual fingers are posteroanterior and lateral. Posteroanterior oblique views should also be obtained for finger metacarpal and proximal phalangeal fractures as dorsal angulation is frequently masked on the lateral view by the adjacent digits (Figure 12.28.3).
Anteroposterior and lateral views in the plane of the thumb (Gedda views) are usually sufficient for thumb fractures. Computed tomography (CT) scans, and other complex imaging techniques are rarely required.
If a closed fracture requires operative treatment or a manipulation and this cannot be performed immediately, the fracture should be temporarily splinted for pain relief. Patients with open fractures should always receive antibiotics and, if necessary, tetanus immunization.
All hand fractures should be screened by a surgeon with an interest in hand fractures. Such a policy reduces the prevalence of unsatisfactory results and prevents overtreatment of simple fractures, which in itself can cause stiffness and generate poor results.
The majority of fractures can be treated equally successfully with a variety of techniques. Both conservative management and operative fracture fixation can produce stunningly good results and humiliating failures. Although fracture factors such as alignment and stability are important determinants of treatment, consideration should also be given to the following.
1) The patient’s expectations of treatment and motivation: although some patients cannot tolerate any cosmetic deformity, many are prepared to accept considerable malunion, provided that normal function is restored. This is especially if acceptance of malunion allows an earlier return to work
2) Rehabilitation resources: aggressive operative fracture fixation should only be performed if appropriate therapy services are available
3) Technical difficulty: trainees and assistants must be shown treatment methods which they will be able to perform independently and safely in the future
4) Cost: do the potential benefits of operative treatment over conservative management justify the extra costs?
Extra-articular fractures (Box 12.28.1)
The treatment goal is union in an alignment which permits normal hand function and provides a cosmetic result which the patient finds satisfactory. Rotational deformity is unacceptable, particularly for metacarpal and proximal phalangeal fractures, and is a strong indication for operative fracture fixation. Metacarpal fractures can tolerate considerable shift and palmar angulation, and some radial/ulnar angulation without loss of function. Proximal phalangeal fractures are much less tolerant of malunion with acceptable limits of about 10 degrees of radial/ulnar angulation and 20 degrees of dorsal/palmar angulation.
Undisplaced and minimally displaced extra-articular fractures
The majority of undisplaced or minimally displaced fractures are stable and should be treated by early mobilization. For phalangeal fractures, this is usually achieved by buddy strapping (Figure 12.28.4) or a Bedford gaiter which holds the injured finger to an adjacent one so as to protect it from unexpected knocks. After 3 weeks most fractures are sufficiently sticky to discard all strapping. Alternatively, if the fracture is very painful or the hand is very swollen, stable fractures can be safely rested on a palmar slab in a comfortable position for 1 or 2 weeks and then mobilized once the pain and swelling have subsided. Stable fractures almost invariably achieve a good result.
However, minimally displaced spiral and long oblique fractures of the proximal and middle phalanges have little axial stability, are potentially unstable and may displace if mobilized (Figure 12.28.5). These fractures should be immobilized on a palmar slab or on an aluminum splint with the hand in the Edinburgh position for 3 weeks.
Displaced extra-articular fractures
The surgeon should assess the configuration of the fracture (transverse, oblique, etc.), so as to predict its axial stability following a closed reduction. If the reduced fracture has little or no axial stability (spiral and long oblique fractures) and accurate fracture alignment is vital, then the fracture should be treated operatively. If the fracture reduction has good axial stability (transverse and short oblique fractures) then the fracture may be treated non-operatively.
Conservative treatment methods
Unstable metacarpal fractures can be immobilized in plasters (Colles plaster, ulnar slab, or hand cast) which allow metacarpophalangeal and interphalangeal joint movement. Unstable proximal and middle phalangeal fractures require immobilization of the injured digit until the fracture becomes sticky (3 weeks). The position in which the injured hand is immobilized and the period of immobilization are of great importance. Fingers should be immobilized in the Edinburgh position (Figure 12.28.6), with the metacarpophalangeal joints flexed to at least 60 degrees and the interphalangeal joints virtually fully extended. In this position the collateral ligaments of these joints are taut and cannot shorten as a result of post-traumatic inflammation. Immobilization of fingers with the metacarpophalangeal joints extended and the interphalangeal joints flexed is a potent cause of interphalangeal joint fixed flexion deformities and reduced metacarpophalangeal joint flexion. It is also a position in which most phalangeal fracture reductions are unstable and will redisplace.
Fractures treated conservatively should be followed up with weekly check radiographs to ensure that the splint does not slip and the fracture does not displace.
Although fracture union, as assessed by bridging callus on radiographs, takes many weeks to occur, firm clinical union is usually achieved after 3 weeks. It is thus rarely necessary to immobilize a finger fracture for longer than 4 weeks.
These are widely used to stabilize fracture reductions and can be inserted following either a closed (percutaneous insertion) or open reduction. Two K-wires are usually used. Crossed K-wires can distract fractures and increase the risk of non-union (Figure 12.28.7).
The advantage of K-wires, especially if inserted percutaneously, is that they provide fracture stability without an extensive surgical exposure. However they may be difficult to insert and are provide relatively unstable fixation Thus, if an extensive surgical exposure with periosteal stripping is required to reduce a fracture, it is probably better to consider rigid internal fixation which allows early mobilization. Another disadvantage is that their tips inevitably protrude into the surrounding soft tissues and can cause irritation and pain, and interfere with rehabilitation. Furthermore, if their ends are left protruding through the skin, troublesome pin site infections can occur. Although these usually resolve once the K-wires have been removed, serious finger infections and osteomyelitis occasionally occur.
Rigid internal fixation
This is a demanding technique. Spiral and long oblique fractures can usually be fixed with lag screw fixation whereas transverse and short oblique fractures require plate fixation. The treatment aim of rigid internal fixation is to make an unstable fracture stable enough to allow early mobilization. Although the benefits of rigid internal fixation are obvious for some fracture types such as the unicondylar fracture of the proximal phalanx, it is uncertain for others whether internal fixation brings about an earlier return of useful function or a better end result than less invasive treatment methods. Tendon adhesions and joint contractures readily develop and the surgeon, therapist, and patient must all be motivated to ensure that the finger is actively mobilized within 1 week in order to prevent these complications. Deep infections following rigid internal fixation are only rarely seen in the hand.
External fixation is not widely used for closed hand fractures though is a useful technique for open fractures (Figure 12.28.8). It causes little soft tissue damage and usually provides sufficient stability to allow early fracture mobilization. There are numerous commercially available hand external fixators, and it is possible to manufacture one from Kirschner wires, the barrel of a syringe and bone cement. Pin site infections can cause troublesome deep infections. External fixators are usually removed after 3 or 4 weeks, once the fracture is sticky.
There are many dynamic traction devices, some of which are expensive and manufactured, while others are assembled out of K-wires by the surgeon during surgery. The principle aim of all these devices is to counteract the tension in the finger extensor and flexor tendons which will cause shortening of injuries without axial stability. This is achieved by applying a distraction force. Dynamic traction is commonly used for the treatment of complex intra-articular fractures of the base of the middle phalanx (Figure 12.28.9).
Specific extra-articular fractures
Extra-articular metacarpal fractures
Metacarpal base fractures of the thumb
Extra-articular fractures of the base of the thumb metacarpal displace into flexion. Provided that there is reasonable contact between the fracture surfaces, considerable deformity (up to a rather arbitrary 30 degrees) can be accepted without loss of thumb function. Most of these fractures are managed quite adequately in a scaphoid-type plaster for 3 weeks. However, if there is gross fracture displacement, comminution, or shortening, closed reduction and percutaneous K-wiring or open reduction and internal fixation (plate or K-wires) should be considered.
Finger metacarpal base and shaft fractures
These fractures, and all other metacarpal fractures, displace into palmar angulation and are most common in the ring and little finger rays. The intermetacarpal ligaments usually prevent rotational deformity though this can occur in all rays. It most commonly occurs with spiral fractures of the distal shaft of the little finger metacarpal.
Palmar angular malunion is well tolerated in the ring and little fingers which have mobile carpometacarpal joints and ‘metacarpalgia’ (synonymous with metatarsalgia) when gripping objects is most uncommon. However, it is more likely to occur following index and middle metacarpal fracture malunions as these rays do not have mobile carpometacarpal joints. Thus, although over 30 degrees of palmar angulation can be accepted in ring and little fingers without fear of significant functional disability, index and middle finger metacarpal shaft fractures with more than 30 degrees of angulation should be reduced. Although 30 degrees of palmar angular malunion of a ring or little finger metacarpal does not cause functional disability, it inevitably causes cosmetic deformity which is more prominent than that following metacarpal neck fracture malunion. For this reason the author usually offers to reduce and immobilize in plaster fractures with 30 degrees or more angular deformity. Fractures with less than 30 degrees of palmar angulation need not be reduced and should be treated conservatively, either by early mobilization or, if painful, by immobilization on a palmar slab for 3 weeks.
Treatment methods for fractures in unacceptable alignment include closed reduction and plaster immobilization (Figure 12.28.10) or percutaneous K-wiring, external fixation and open reduction and internal fixation with K-wires, screws, or plates. Although these fractures are easily reduced closed, it is difficult to maintain the reduction in plaster and redisplacement can occur, either during plaster immobilization or after the plaster has been removed at 3 or 4 weeks. For this reason, operative fixation should be considered for all fractures with rotational deformity and those which have completely ‘stepped off’ and telescoped (causing shortening). Operative fixation should also be considered when the cosmetic result is important, though one is trading in a bony bump and a sunken knuckle for a scar. Percutaneous K-wiring can be performed by reducing the fracture and passing three transverse K-wires, two distal and one proximal to the fracture, across from the fractured metacarpal into the adjacent metacarpal. Alternatively, these fractures can be stabilized by one to three intramedullary K-wires which are inserted through a small cortical window in the metacarpal base or neck. This technique is particularly suitable for the little finger metacarpal but is not as easy as it may appear (Figure 12.28.11). Most patients rapidly regain hand function and, if the K-wires are buried in the metacarpal shaft, they rarely migrate and require removal.
Lag screws can be used to fix spiral metacarpal shaft fractures but, if open reduction and internal fixation is the chosen treatment option, plate fixation is usually required. If plates are used, early postoperative mobilization is essential so as to prevent adhesion formation.
It is not unusual for patients with little finger metacarpal shaft fractures which have been reduced and stabilized in plaster to default from clinic and remove their plasters. Although such fractures may unite in gross palmar angulation (up to 60 degrees) and the cosmetic appearance may be unsightly, function is good.
Finger metacarpal neck fractures
Little finger metacarpal neck fractures are usually self-inflicted in a fight and displace into palmar angulation. Although this angular deformity is readily reduced, it is virtually impossible to maintain the reduction with closed methods. Excellent functional results can be achieved within 3 weeks by ignoring the fracture displacement and mobilizing even the most severely displaced fracture. The patient should be warned that he will be left with a bony bump and a sunken knuckle and initially may have a metacarpophalangeal and even a proximal interphalangeal joint extension lag. Operative fixation is reserved for fractures with complete step off or patients who cannot accept deformity. Metacarpophalangeal joint stiffness is not an infrequent complication of operative fixation, especially if blade plates are used.
Considerable palmar angulation can also be accepted in ring finger metacarpal neck fractures. However, index and middle finger metacarpal neck fractures must unite in reasonable alignment as these digits do not have mobile carpometacarpal joints which can extend and prevent the metacarpal head becoming prominent in the palm. Fortunately, metacarpal neck fractures in these rays are rare and they are usually only minimally displaced. Thus, most finger metacarpal neck fractures are treated conservatively.
Extra-articular phalangeal fractures
Extra-articular proximal and middle phalangeal fractures
Displaced fractures of the proximal and middle phalanges are a common cause of finger stiffness. This occurs either as a result of malunion or adhesion formation between the fracture and the flexor tendon or the extensor hood which enshrouds the dorsal and lateral surfaces of the proximal phalanx.
Proximal phalangeal fractures displace into dorsal angulation and are easily reduced by traction and flexion of the metacarpophalangeal joint. Fractures of the distal third of the middle phalanx also displace into dorsal angulation whereas proximal third fractures displace into palmar angulation. Middle phalanx fractures tolerate angular and rotational malunion better than fractures of the proximal phalanx.
Extra-articular fractures of the base of the proximal phalanx.
These displace into dorsal angulation which is frequently missed on radiographs as the fracture is obscured by the other fingers on the lateral view (Figure 12.28.5). Malunion with dorsal angulation disrupts the fine balance between the extensor mechanism and the flexor tendons, and may result in a boutonnière deformity. In addition, an apparent loss of metacarpophalangeal joint flexion may occur. These fractures usually have a transverse configuration though there may be considerable dorsal comminution, especially in the elderly.
They readily reduce with metacarpophalangeal joint flexion and the reduction can then be maintained in a well-fitting plaster cast or Zimmer splint which holds the finger in the Edinburgh position. It is vital that the plaster/splint is checked and the fracture is radiographed weekly for 3 weeks, as the plaster/splint all too readily slips distally allowing metacarpophalangeal joint extension, fracture redisplacement, and proximal interphalangeal joint flexion (Figure 12.28.12). This is a potent combination for finger stiffness, and boutonnière deformities often develop. Because of these difficulties, some surgeons prefer to treat these fractures operatively, either with percutaneous K-wires, rigid internal or external fixation. A condylar blade plate provides good stability, but is uncompromising, very difficult to apply and may result in stiffness due to extensor tendon adhesions, especially if the patient is reluctant to move his or her finger postoperatively. It is not known whether any form of operative fixation produces better results than careful non-operative management.
Phalangeal shaft fractures.
The majority of displaced transverse and short oblique fractures of the phalanges can be treated satisfactorily by closed reduction and immobilization in the Edinburgh position for 3 weeks. Spiral fractures have no axial stability after reduction, tend to redisplace and are a common cause of rotational malunion. Long oblique fractures may produce a bone spike which blocks proximal interphalangeal joint flexion (Figure 12.28.7). These fractures may be treated satisfactorily by closed reduction and K-wire fixation (Figure 12.28.13), or open reduction and lag screw fixation (Figure 12.28.14) with similar outcomes (Horton et al., 2003). Percutaneous K-wiring under radiographic control is not as easy as it may appear as the phalangeal shaft cortices are thick. Lag screw fixation is readily complicated by proximal interphalangeal joint fixed flexion deformities which can cause cosmetic deformity and loss of function, but are not usually severe if appropriate rehabilitation is provided.
Phalangeal neck fractures.
Fractures of the neck of the proximal phalanx in adults are almost always transverse and can be treated non operatively by closed reduction and immobilization in the Edinburgh position which is modified slightly to incorporate slight flexion of the proximal interphalangeal joint (Figure 12.28.15). However these injuries often occur in young children who have caught the finger in the hinge-side of a door and these cannot be safely managed non-operatively due to poor compliance and chubby small fingers. These injuries will not remodel as they are away from the growth plate. Closed reduction and percutaneous K-wire fixation which transfixes the proximal interphalangeal joint is recommended in this situation. If the child presents late (more than 1 week, then it may be impossible to manipulate the fracture back into normal alignments, but an open reduction can usually be avoided by inserting a green hypodermic needle into the fracture (introduced dorsally) and using this to lever the distal fragment back into place: the fracture can then be K-wired (Figure 12.28.16).
Extra-articular distal phalangeal fractures
These can involve the tuft or the metaphysis. Tuft fractures are usually caused by crush injuries and often have associated painful subungual haematoma. These fractures should be treated conservatively though associated soft-tissue injuries (nailbed and skin lacerations) may require surgery and painful subungual haematoma should be drained. They are best treated by early mobilization but can be splinted for 1 or 2 weeks if very painful.
Metaphyseal fractures also usually occur following crush injuries and again overlying nailbed injuries are common. If undisplaced, these fractures should be treated by early mobilization. If displaced, these fractures should be reduced in order to prevent cosmetic deformity and abnormal nail growth, and reduce the risk of non union (Figure 12.28.17). The reduction can usually be maintained by a dorsal or palmar splint though some prefer percutaneous K-wires.
Joint stiffness, joint instability, and post-traumatic osteoarthritis are specific complications of intra-articular fractures. These complications, as well as fracture alignment and stability, should always be considered when planning the treatment of intra-articular fractures. Furthermore, the likely outcomes of non-operative treatment (early mobilization or splintage) and operative fixation should be compared and the feasibility of worthwhile fracture fixation should be assessed.
As a general rule, the thumb and finger carpometacarpal, metacarpophalangeal, and distal interphalangeal joints tolerate articular incongruity reasonably well and rarely develop troublesome post-traumatic osteoarthritis or stiffness. In contrast, troublesome post-traumatic osteoarthritis and stiffness are well-recognized complications of some intra-articular fractures of the proximal interphalangeal joint.
Trapeziometacarpal joint fractures
Bennett’s fracture of the thumb metacarpal is a two-part fracture–dislocation of the trapeziometacarpal joint without significant articular comminution (Figure 12.28.18). The palmar metacarpal fragment retains its attachment to the strong ulnar ligament of the thumb trapeziometacarpal joint and thus joint stability is restored following fracture union in anatomic alignment. Although Bennett’s fractures are easily reduced thumb traction and abduction, the reduction is unstable and redisplacement often occurs if the fracture is treated conservatively in a Bennett’s plaster. Such malunion causes persistent stiffness, weakness and pain and these fractures are more reliably treated by closed reduction and percutaneous K-wiring. The K-wire(s) may either pass between the bases of the thumb and the index finger or across the trapeziometacarpal joint. The thumb should then be immobilized in a scaphoid plaster for 4–6 weeks, thus allowing fracture union in good alignment. Of thumbs treated in this manner 80% are painless at 6-year follow-up and few of the remaining 20% experience significant pain or disability. However, 50% have radiological post-traumatic arthritis.
For Bennett’s fractures with large palmar fragments, open reduction and lag screw fixation is not inappropriate, though care must be taken not to damage sensory branches of the radial nerve or the palmar cutaneous branch of the median nerve.
Intra-articular fractures of the base of the thumb metacarpal with articular comminution are more difficult to treat. If the articular congruity and fracture alignment are reasonable, cast immobilization for 3 weeks may be the best option. Displaced fractures with two main articular fragments (Rolando’s fracture) can be treated by open reduction and internal fixation with either K-wires or a T-plate. If there is a metaphyseal defect caused by cancellous bone impaction, this should be bone grafted. Operative fixation of these fractures is never simple and becomes technically much more demanding with increasing comminution. Ligomentotaxis using a small external fixator attached to the thumb and index metacarpal shafts is a worthwhile option for fractures with severe comminution.
Fractures of the base of the little finger metacarpal with carpometacarpal joint subluxation are similar to the Bennett’s fractures. The small radial fragment retains the strong intermetacarpal ligament attachment and the little finger metacarpal base displaces ulnarly or, more usually, dorsally. Axial traction on the little finger readily reduces these fractures, which can then be stabilized with percutaneous K-wires which is passed through the base of the little finger metacarpal, either into the hamate bone or the ring metacarpal base.
Metacarpophalangeal joint fractures
Metacarpal head fractures
These usually occur as a result of an axial force (punch) and are most common in the index finger. Unless there is a large articular step (not gap), these fractures can be treated by active early mobilization with good results. If there is considerable articular incongruity and a single large fracture fragment (usually a palmar fragment), open reduction and internal fixation is indicated. However, many of these fractures are comminuted and difficult to fix as the bone is thin and friable. For such fractures conservative management with early mobilization is probably prudent.
Fractures of the base of the proximal phalanx
Collateral ligament avulsion fractures from the bases of finger proximal phalanges usually involve less than one-third of the articular surface. Such fractures should be mobilized in buddy strapping without fear of subsequent joint instability as persistent symptoms are unusual. Displaced avulsion fractures with larger articular fragments (more than 30% of the articular surface) should be treated by open reduction (palmar approach) and internal fixation, using either a K-wire or a lag screw.
Avulsion fractures of the thumb ulnar collateral ligament with less than 3mm of displacement can be satisfactorily treated by immobilization in a scaphoid-type plaster for 3 weeks. Avulsion fractures with greater displacement or marked rotation should be treated by open reduction and internal fixation, using a K-wire or a single lag screw if the fragment is sufficiently large (Figure 12.28.19). Avulsion fractures of the thumb radial collateral ligament are treated conservatively unless they involve a large portion of the articular surface. This rationale for treatment is based on the fact that ulnar collateral ligament stability is vital for pinch grip whereas radial collateral ligament stability is not critical to thumb function.
Proximal interphalangeal joint
Condylar fractures of the proximal phalanx
There is almost universal agreement that displaced unicondylar fractures of the proximal phalanx are best treated by open reduction and internal fixation. These fractures usually have no axial stability and, if treated conservatively, almost inevitably unite with shortening and palmar or dorsal displacement. This causes a radial/ulnar angulation when the finger is extended and a rotational deformity when it is flexed. The unicondylar fracture fragment is usually sufficiently large to permit open reduction and internal fixation with a 1.5-mm or smaller lag screw (Figure 12.28.20) which should be placed just proximal to the origin of the collateral ligament. Alternatively, these fractures may also be stabilized with one or two K-wires. Proximal interphalangeal joint movement is usually slightly diminished following unicondylar fracture fixation and a 10-degree fixed flexion deformity and an 80-degree arc of flexion are typical.
Bicondylar fractures of the proximal phalanx require careful assessment. If the general alignment of the proximal interphalangeal joint is reasonable and there is no angular or rotational deformity, the position of the fracture can be accepted. The finger is then rested in the Edinburgh position for 3 weeks. Surprisingly good results can be achieved with this method though most surgeons now favour open reduction and internal fixation using multiple K-wires, lag screws, or even a condylar blade plate. The best treatment method varies from fracture to fracture and some loss of proximal interphalangeal joint movement is to be expected.
These fractures can be classified as follows:
♦ Dorsal avulsion fractures of the central slip
♦ Palmar lip fractures with or without dorsal subluxation of the proximal interphalangeal joint
♦ Impaction fracture.
Dorsal avulsion fractures
These are avulsion fractures of the central slip of the extensor mechanism and they often allow palmar dislocation of the proximal interphalangeal joint. If the fracture fragment is sufficiently large, open reduction and internal fixation may be performed, especially if the proximal interphalangeal joint is dislocated and the reduction is unstable. A 1.5-mm or smaller lag screw or a K-wire can be used though care must be taken not to split the fracture fragment as the dorsal cortex is thin and the fragments are small (Figure 12.28.21). Smaller fracture fragments are treated with good results by splinting the proximal interphalangeal joint in extension for 3 weeks. However, radiographs should always be obtained with the finger in the splint in order to ensure that the fracture fragment lies in reasonable alignment and the joint, if previously dislocated, remains congruent.
Palmar lip fractures
Small palmar avulsion fractures without associated proximal interphalangeal joint subluxation or dislocation are caused by hyperextension injuries. These are treated by early mobilization but the patient should be warned that the proximal interphalangeal joint may remain swollen and tender for many months. Full finger flexion will only be regained once the swelling has settled, and there may be a permanent fixed-flexion deformity of the proximal interphalangeal joint.
Larger palmar lip fractures of the base of the middle phalanx cause dorsal subluxation of the proximal interphalangeal joint and are often comminuted with impacted central articular fragments (Figure 12.28.22). These injuries are caused by axial compression forces and are frequently inflicted by cricket or basket balls. Their prognosis depends on patient motivation, the degree of fracture comminution, and the percentage of the articular surface which is damaged. The proximal interphalangeal joint readily reduces with traction and flexion and the injury is then stable, provided that extension of the proximal interphalangeal joint is restricted. This can be achieved with extension block splintage, percutaneous K-wiring, dynamic traction or external fixation of the proximal interphalangeal joint. Some surgeons favour open reduction and internal fixation of these fractures, particularly those with more than 50% involvement of the articular surface, but this is complex surgery which is not always successful. Extension block splints are worn for 4–6 weeks and the results for fractures involving less than 30% of the articular surface are usually good This treatment method works well in motivated patients, but requires careful follow-up to ensure that the proximal interphalangeal joint does not resublux within the splint. Percutaneous K-wiring of the proximal interphalangeal joint in sufficient flexion to reduce the dorsal subluxation requires less patient cooperation. The K-wire is removed after 4 weeks and the finger is then actively mobilized, producing satisfactory outcomes. A few of these fracture–subluxations resublux after the K-wire, external fixator, or extension block splint is removed. All treatment methods usually produce a painless stable proximal interphalangeal joint which flexes to 90 degrees though has a 10–30 degrees fixed flexion deformity. The long-term results of non-operative treatment of these injuries are not as bad as may be anticipated and considerable joint remodelling can occur.
Distal interphalangeal joint fractures
Condylar fractures of the middle phalanx
These are treated in the same manner as those of the proximal phalanx.
Intra-articular fractures of the base of the distal phalanx
These can be classified as follows:
♦ Avulsion fractures of the flexor digitorum profundus insertion (covered in Chapter 12.22)
♦ Palmar lip fractures (avulsion fractures of the palmar plate)
♦ Avulsion fractures of the extensor expansion (mallet fractures)
♦ Other intra-articular fractures.
Palmar lip fractures
These may cause dorsal subluxation of the distal interphalangeal joint. Although large single fragments involving more than 30% of the articular surface can be treated by open reduction and internal fixation, the majority of these fractures have small fracture fragments and any associated joint subluxation can be reduced by splinting the distal interphalangeal joint in flexion for 4 weeks.
Mallet fractures can cause palmar subluxation of the distal interphalangeal joint (Figure 12.28.23). Their treatment is controversial but those with a fracture fragment which involves less than a third of the articular surface and no associated joint subluxation are reliably treated conservatively by splinting the distal interphalangeal joint in extension for 4–6 weeks. This is most easily achieved with a polyethylene Stack splint or thermoplastic which must be worn continuously. There is usually soreness at the fracture site for several months but this almost always resolves. Larger fracture fragments can also be successfully treated conservatively and some consider that this is also the treatment of choice for fractures with associated distal interphalangeal joint subluxation. Others consider that the presence of joint subluxation necessitates operative fixation, either with a lag screw or K-wires (Figure 12.28.24). Although there is a trend towards lag screw fixation of large fragment fractures, there is no evidence that this produces a better result than splintage, and the screw head is relatively bulky and the overlying skin is thin such that wound problems may occur. This is also discussed in Chapter 12.23.
Open metacarpal and phalangeal fractures should be treated as other open fractures, with thorough soft tissue irrigation and debridement and fracture stabilization so that the damaged soft tissues can be inspected and gently mobilized. External fixation is particularly useful for these fractures.
Multiple hand fractures
Multiple fractures in unsatisfactory alignment are usually best treated by operative fixation, especially if there is more than one fracture in each ray or each ray contains a different type of fracture. This is because it is difficult to manipulate and maintain multiple fracture reductions with conservative methods.
Metacarpal and phalangeal fractures in children
These fractures heal more rapidly than their adult counterparts. Although dorsal/palmar angular malunion may improve with remodelling during growth if the fracture is in the midshaft or at the end of the bone containing the growth plate, radial/ulnar and rotational malunion do not improve with growth.
In general, paediatric hand fractures should be treated in a similar manner to adult fractures. However, most extra-articular fractures which require operative fixation can be managed with K-wires and plate fixation is rarely indicated.
The major complications of metacarpal and phalangeal fractures are as follows:
♦ Malunion (rotational or angular) causing loss of hand function
♦ Finger stiffness
♦ Post-traumatic osteoarthritis
If a rotational deformity is detected within 8 weeks of injury, it is usually possible to take the fracture down and internally fix it in satisfactory alignment with K-wires or a plate. However, this is difficult surgery and the patient should be warned of the risks of osteotomy non-union and finger stiffness. A safer option, which should be used for rotational deformities detected after 8 weeks, is to regain full finger movement, allow the fracture to unite, and then perform a rotational osteotomy, either through the base of the fractured bone or through the base of the finger’s metacarpal. The latter can be stabilized either with K-wires or a small plate, and is most unlikely to be complicated by finger stiffness.
Angular malunions which interfere with finger function are treated with a corrective osteotomy at the fracture site.
This can either be due to joint contracture or tendon adhesions and both can complicate either conservative treatment or operative fixation. Loss of finger extension, unless severe, usually causes little disability. Loss of finger flexion is much more disabling and can cause loss of dexterity and hand weakness, especially if it causes quadriga.
Stiffness due to joint contractures results in equal losses of active and passive movement. In stiffness due to tendon adhesions, the range of passive movement exceeds the range of active movement.
Joint contractures are difficult to treat but should initially be managed with physiotherapy and splintage. If this fails then surgical release of the contracted joint capsule and ligaments may be indicated, but the results of this surgery are unpredictable. In severe cases, the patient may be best managed with an amputation.
Tendon adhesions are also initially treated with vigorous physiotherapy. If they persist, a tenolysis should be performed once the fracture has firmly united. Postoperatively, the patient undergoes an intense course of physiotherapy.
The treatment of this condition, if symptomatic, is no different from that of other types of osteoarthritis.
Fracture non-union is rare in metacarpal and phalangeal fractures, even though radiographic evidence of fracture union takes many weeks to develop. However, fractures which are treated operatively and fixed with distraction, frequently develop non-union. Non-union, if symptomatic, is treated by internal fixation and bone grafting.
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