Diagnosis and Treatment of Common Hand Injuries
Injuries of the hand can be described based on the six tissues involved: skin and subcutaneous tissues, tendon and muscles, blood vessels, nerves, bones and joints. Fingertip injuries, on the other hand, may involve the nailbed, bone (distal phalanx) and pulp tissue. The treatment protocol is basically as follows: If there is a laceration with no tissue loss, simple repair is sufficient. If there is tissue loss, one needs to import tissue, either to replace or reconstruct. However, if more than 50% of the tissues are lost, terminalisation is a more viable option than reconstruction.
The time, mechanism and environment of the injury are important factors in assessing the case. These help us to determine the urgency of the problem, zone of injury, as well as the degree of contamination. Contamination with organic matter like raw meat, and animal and human bites is fraught with a false sense of adequate cleansing and debridement. The contamination is usually fluid in nature and cannot be seen. This leads to inadequate debridement and often results in wound infection. It is a good practice to delay closure of wounds from animal and human bites. Penicillin is also added if biological contamination is present. In situations whereby marine organisms are suspected, doxycycline is included instead. Open injuries from blunt trauma and crush injuries are often associated with a wider zone of injury; hence, it may be necessary for a zone of necrosis to be excised and monitored before wound closure. An X-ray is also indicated to exclude any foreign body in the wound. Injuries involving blood vessels warrant a sense of urgency as failure to repair or re-establish the blood supply results in necrosis or gangrene on the distal part. As a guide, we usually try to establish re-vascularization to a digit within 12 hours, and within 6 hours in injuries affecting muscles. The amputate should be properly preserved in clean gauze and kept in a clean dry bag, which is then kept immersed in a bag of ice. This is to ensure that the amputate is kept cool, but not frozen or wet.
Accurate diagnosis cannot be overemphasized. One should go through a mental checklist of the six tissues in the hand. Any suspected diagnosis should be followed up with further investigations (e.g. X-ray of the finger for bone injury), or surgical exploration. Injection of tetanus toxoid should be given if the patient has not had it within 5 years. Appropriate broad-spectrum antibiotics should be instituted as well.
This is a common injury. It is usually caused by a blunt crush trauma (e.g. a slamming door) or a sharp cut laceration (e.g. by a knife). The crush injury may result in a stellate laceration of the nailbed, requiring careful nailbed repair, akin to arranging them like pieces in a jigsaw puzzle. Fingertip injuries can be classified based on the size of skin loss. Superficial skin loss of an area less than 5mm in diameter may be treated with wound dressings and secondary intention healing without significantly affecting the function of the hand. Wounds larger than 5mm, but not more than 1cm, may be amenable to a local V-Y plasty. Defects larger than 1cm generally require a larger flap such as a cross finger flap or a heterodigital island flap. In most injuries with associated tuft fractures, conservative treatment approaches are usually adequate. However, if the fracture is through the shaft or base of the distal phalanx, fracture reduction and internal fixation with metal wires will be required.
Open Wounds with Cut Structures
Examination of the hand should include the tendons flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP) and extensor digitorum communis (EDCs). Sensory function is provided by the radial and ulnar digital nerves, and usually light touch or 2 point-discrimination (2PD) can be used as an examination tool. Arterial injury must be excluded in any laceration on the palmar surface of the finger, hand or wrist. If the resting cascade of the hand is abnormal, one should exclude any tendons disruption in the hand. Early repair of cut tendons is preferred for better function recovery and to facilitate primary repair. In delayed situations, tendon transfer or tendon grafts may have to be performed. Post operatively, these patients are referred to occupational therapists for the appropriate rehabilitation protocol.
Both radial and ulnar digital arteries need to be cut before vascular compromise to the distal part occurs. Sometimes this is not grossly apparent, especially if the digit is still hanging by some soft tissues. Thus, one has to specifically examine for circulation in the distal part by examining the colour, capillary refill, turgor and temperature. In complete amputation injury, careful preservation of the amputated part is just as important as the urgency for treatment of the injury. The more proximal the amputation, the greater the urgency for replantation. Prolonged ischaemia will result in muscle necrosis and reperfusion injury.
Hand fractures are treated more aggressively. Prolonged immobilization leads to stiffness, and despite aggressive occupational therapy intervention, recovery in the range of motion may remain limited. Early surgical internal fixation will allow early mobilization and subsequently, better range of motion. An innocuous looking fracture on an X-ray may actually have significant rotational deformity upon clinical examination. On the same note, at least 2 views are required for an X-ray, before a fracture can be excluded.
Surgical fixation of distal radius fractures is also more prevalent nowadays as we have had good experience with it compared to conservative management. Surgery allows us to better control and improve the fracture alignment, instead of accepting the deformity and stiffness from conservative casting methods.
Skin laceration with fractures may arise from an external object inflicting the wound or the sharp edge of the angulated fracture lacerating the skin from inside out and then recoiling back in the wound. These are considered open fractures and should be treated urgently with wound debridement. A severely comminuted fracture or displaced dislocation may also be associated with neurovascular or tendon injury. Thus, one must deliberately examine for these possible associated injuries. In open injuries in the hand and wrist, only the skin injury is clearly apparent. Undiagnosed and untreated injuries to the other tissues often lead to significant disability, compromising the function of the hand. Inappropriate treatment according to the nature and extent of the skin injury also leads to significant disability.
The more proximal the amputation, the greater the urgency for replantation.
Prolonged ischaemia will result in muscle necrosis and reperfusion injury.
A Specialist’s Point of View – Written by Dr Tan Puay Ling
Dr Tan Puay Ling
MBBS (Singapore), MRCS (Edinburgh)
MMed (Surgery), FAMS (Hand Surgery)
Dr Tan Puay Ling completed her medical degree at the National University of Singapore in 1998 and attained Master of Medicine in Surgery (NUS) in 2002. She was awarded the Health Manpower and Development Plan in 2006 and spent one year at the prestigious Chang Gung Memorial Hospital (Linkou) under the guidance of Dr FC Wei and Dr David Chuang, who are all renowned specialists in microsurgery and paediatric hand surgery. Her keen interest in hand & wrist arthroscopy has also brought her under the wings of Dr AL Osterman from Philadelphia Hand Centre and Dr PC Ho from Prince of Wales Hospital, Hong Kong SAR.
Dr Tan is a Visiting Consultant at the Tan Tock Seng Hospital.
Dr Tan is well respected in her area of specialty and served as the Chairman of the Chapter of Hand Surgeons, College of Surgeons, Academy of Medicine Singapore from 2014-2016.
Her active involvement in education and research saw her as the Program Director for the National Healthcare Group Hand Surgery Program from 2011 to 2013. She as also active in teaching the undergraduates and served as senior clinical lecturer in Yong Loo Lin School of Medicine, NUS prior to starting her own practice. She was also the Director and Chairman of the Surgical Sciences Training Centre in Tan Tock Seng Hospital. She has published extensively in numerous international journals and also a book chapter in the referenced text “The Art of Microsurgical Reconstruction”.
Prior to establishing her private practice, Dr Tan was the Head and Consultant
of the Hand & Microsurgery Section, Tan Tock Seng Hospital.
She is currently the Medical Director of Westpoint Hospital.
Infinity Hand, Wrist & Reconstructive Surgery Centre
#14-12, Mount Elizabeth Medical Centre,
3 Mount Elizabeth, Singapore 228510
Tel: 6735 4220 Fax 6735 6220