The use of the hand in sports is widespread. Whether in direct handling by the protected or unprotected hand its vulnerability to direct or indirect trauma can be estimated by the numbers of injuries which present at specialised sports or hand injuries clinics. Even in those sports in which the hand is protected by the use of gloves, as in cricket or boxing, there still remains a large number of injuries presenting at hospitals.
The hand may be used without protection for ball handling, catching, throwing or through its constant grasping and power function with various forms of bats, rackets and weights or even as an organ of communication in gesturing or signalling to other participants or spectators.
THE ANATOMY OF THE HAND
Connected to a large area of the sensori-motor cortex, the nerve supply to the hand comes mainly through the median, ulnar and radial nerves; the former two deliver both a sensory supply to the skin and a motor supply to the intrinsic muscles. The radial nerve limits itself to a sensory supply only. In addition, a rich complex supply is afforded by all three nerves to the sweat glands and blood vessels making the hand an important regulator of temperature of the body as a whole. On the front of the hand a marginal contribution to grip is made by the sweat gland secretion.
Basically, the bony skeleton of the hand consists of a platform made up of small carpal bones proximally and a radiating quadumvirate of metacarpal bones, the thumb metacarpal being placed laterally and almost in a plane at right angles to the other metacarpals. From the medial four metacarpals the three phalanges to each finger arise and from the thumb the shorter phalangeal chain of two phalanges. The fine movements of the digits are controlled by intrinsic muscles and the grosser movements by extrinsic tendons, I.e. the flexors on the front and the extensors behind.
The basic pattern of power, pinch and hook grips are applied to fingers and thumb. Additionally, the hand may be used in sports in the ‘paddling’ position or as a ‘platform’ with the wrist hyperextended in swimming and floor gymnastics respectively.
LIGAMENTOUS INJURIES OF THE FINGERS AND THUMB Anatomy
The metacarpo-phalangeal joints are of the condyloid variety, each having a palmar and two collateral ligaments . In the fingers, side-to-side movements of the thumb metacarpo-phalangeal joint are much more restricted. The palmar ligaments are of thick, dense fibrocartilage attached on either side to the collateral ligaments, loosely to the metacarpal and firmly to the phalangeal bases. In addition they blend on either side to the deep transverse ligaments of the palm and their sides give attachments to the fibrous flexor tendon sheaths.
Sprain of the collateral ligaments of the metacarpo-phalangeal joints Sprains of the collateral ligaments are common in the thumb, but less common in the finger metacarpal joints. The former lead to continued pain and swelling which constitutes a severe handicap to thumb usage in gripping and untoward sudden sideways strains. Patients should be warned of these continued effects. In the initial stages it is often better to protect the ligaments by a small splint made from three to four sheets of plaster of Paris moulded directly on to the thumb, maintained for two to three weeks; later, continued pain can be lessened by an injection of hydrocortisone around the joint. With metacarpophalangeal joint sprains, again they should be immobilised initially by a metal well-padded splint extending from the butt of the palm up to the distal joints of the finger for two to three weeks. These injuries seem not to have continued pain, as in the thumb collateral ligament joint sprains, and can be protected by immobilising with strapping to adjacent fingers.
Sprains of the proximal interphalangeal joint ligaments The collateral ligaments of the proximal finger joints appear especially vulnerable to sprains sustained mostly during body contact sports. The immediate swelling and pain may be more pronounced unilaterally and the finger joint should be tested for instability and x-rayed. During the painful initial stages it is wise to immobilise the joint for up to ten days, then mobilise the finger by gartering to the adjacent fingers. The patient should be warned of persistent swelling in the joint with some discomfort on movement .
Collateral ligament rupture at metacarpo-phalangeal level With greater violence the collateral ligaments are prone to complete division. They usually rupture at joint line level but may be avulsed with bone fragments at either end; instability ensues and it is detected clinically by stressing laterally the affected joints.
The small and ring fingers would appear to be the most common fingers to be affected. Treatment for certainty should be operative, as conservative treatment cannot guarantee as good a result. In the author’s experience the resultant disability of instability where treatment was expectant weighs heavily towards operative treatment. Repair of the ligaments should be afforded by interrupted white silk and the fingers maintained at 60° flexion for three weeks. In the thumb, similar operative treatment is necessary where the most common injury is to the collateral ligament on the ulnar side. Non-operative treatment often leads to instability, an extremely disabling condition.
In those undetected ruptures and in long-term disability an attempt should be made to construct new collateral ligaments by free fascia lata grafts, although no absolute guarantee can be given to completely cure the instability. The only absolute cure, but which is difficult to obtain, is by metacarpo-phalangeal fusion in a position of function; thumb mobility being ensured by the basal carpo-metacarpal and terminal inter-phalangeal joints.
Operative repair is needed for fresh injuries. It is necessary to maintain the finger in the mid-range position postoperatively at about 45° of flexion for three weeks, with some ‘lively’ splintage following for a further three to four weeks. Long-term results have shown the success of this aggressive treatment with only a minimal loss of flexibility in a few instances.
CLOSEDTENDON INJURIES IN THE HAND
Direct finger-tip injury from ball-game pursuits often results in ‘attritional’ lengthening of the extensor tendon insertion; the flexion deformity resulting at the terminal interphalangeal joint is known colloquially as a ‘mallet’ finger . The deformity is corrected by application of one of the plastic splints of which many are on the market and maintained for five weeks. If the deformity is of the magnitude of 90°, it is considered better to operate and overcome the tendon lengthening by ‘darning’ the tendon over the joint with white silk, afterwards maintaining the joint in extension for three weeks. Slight loss of flexion range may result in the long term.
Occasionally indirect trauma to the extensor tendon ‘middle slip’ insertion over the proximal phalanx occurs again with attritional lengthening of the insertion. The resultant deformity is the ‘boutonniere’ finger where the terminal interphalangeal joint remains in extension and the proximal interphalangeal joint adopts an attitude of flexion . The lateral slips of the extensor mechanism move away from their anatomical axis and cause the deformity. Fresh injuries are treatable by splintage in an attempt to reverse the deformity. The splint should be close fitting and maintain the proximal joint in extension and the terminal joint in flexion. Late deformities should undergo operative treatment whereby the extensor is restored as best as possible to its anatomical position.
FINGER AND THUMB DISLOCATIONS
Most finger joint dislocations occur at the proximal interphalangeal joints with body contact sports. The middle phalanx is displaced backwards and results in the clinical ‘step-off which is so easily recognised: on the spot diagnosis is easy and often the joint is restored by a single sharp traction on the finger. As the joint capsule is not breached this manoeuvre is, in the majority of cases, successful. Simple gartering to adjacent fingers is all that is necessary but it is imperative to check reduction by x-ray. In the thumb, the common displacement is at the terminal joint and re-position is done in the same way. Occasionally both interphalangeal joints can be concomitantly displaced in a ‘stairway’ fashion.
The rare metacarpo-phalangeal dislocation where the proximal phalanx is displaced backwards on the metacarpal head demands care, as the volar capsule often ‘buttonholes’ and renders closed manipulation impossible. It is in such cases that open reduction and re-position is necessary because of the trapping effect on the metacarpal head.
PERI-ARTICULAR AND FRACTURES
Intra-articular fractures without significant joint surface deformation These fractures are treated by gartering the injured digit to the neighbouring digit from which it tends to deviate. Finger movements are encouraged immediately.
Fractures without significant displacement usually only involve one condyle of the proximal phalanx and are treated by gartering. Fractures with displacement are usually unstable, rotation resulting in effacement. Treatment is operative with Kirschner wire fixation. Even after restoration, occasionally the fragment may die but its buttressing effect can have a fair outcome.
This injury commonly occurs in body contact sports and from falls. The outcome is an intra-articular fracture through the base of the thumb metacarpal with a variably sized triangular fragment of bone remaining articulated while the main shaft carrying the larger articular surface is displaced. The resultant pain and swelling at the thumb base is easily detected and the fracture confirmed by x-ray.
Treatment is by operative reduction of the fracture and screw fixation through the fragment which allows anatomical re-position of the metacarpo-carpal relationship. The consequent stability ensures restoration of movement and delays possible later degenerative osteoarthritis.
Chip or flake fractures around joints
Without displacement, chip or flake fractures are commonly seen at the bases of the middle phalanges. If the joint is stable then simple splintage is all that is necessary for three weeks.
Where the fracture occurs with displacement and the joint is unstable then open fixation should be done. However, late diagnosis often leads to a fair result.
Fractures of the head or necks of metacarpals
These fractures are common sporting injuries particularly in boxing. Those through the metacarpal head can be left alone and healed by elevation and early movement. With fractures through the metacarpal neck significant displacement can occur. The head moves into the palm of the hand and the fracture angulates backwards. Moderate angulation can be left alone but significant displacement should be reduced by manipulation: if this is unsuccessful then open operation should be performed.
It is important to realise that hand injuries in sports require adequate first and second treatment. First aid requires the services of an adequately trained first aider, physiotherapist or doctor on site at the time of the injury. Simple immobilisation and, above all, elevation of the hand is all that is necessary. Second aid, which should always follow, should be afforded at a special hand clinic at hospital run by a specialist in hand surgery. Too often hospital care is left to a junior doctor without supervision and poor results follow. Within the same confines physiotherapists and occupational therapists should work within the hand service team, for it is only by team work that the very best results are achieved.