clenched fist injury is resulted from hitting the other person into his front teeth , usually after a fight.1 , 2 consequently , the tooth penetrates through the skin and in some cases it passes through the extensor tendon into the joint . the literature describes several options of surgical treatment for such injuries , but negative pressure wound therapy ( npwt ) is missing . a 30 years old man was admitted into the emergency department with swelling and pain of the right hand . locally , a 5  mm long wound was presented over the third metacarpophalangeal ( mp ) joint with redness and swelling ( fig .  1 ) . laboratory tests revealed increased number of white blood cells ( 12.38    10/l ) and elevated c - reactive protein level ( 55.01  mg we performed the tissue debridement and took samples for microbiological examination . during the revision , we found partial lesions of the extensor mechanism . after washout , the wound was left open . microbiological tests cultivated massive streptococcus gordonii and gram - positive anaerobic bacteria sensitive to cefuroxime and clindamycin . in the coming days of hospitalization , white blood cells and elevated c - reactive protein level magnetic resonance imaging scan was performed and indicated the osteomyelitis and septic arthritis of the third mp joint with the abscess foci ( 22  mm    15  mm    27  mm ) in the dorsum of the right hand ( fig . 2 ) . throughout the second revision , npwt with polyurethane foam and redon drainage were applied . skin wound over the foam position was closed by suture and foil ( fig . subsequently , the wound was revised for three times with repeated use of npwt and wound suture over the foam placement . microbial cultivation collected after the fourth revision remained negative . during the fifth revision the wound healed with mild hypertrophic scar and a painless unremarkable swelling , without fistulas or other signs of persistent infection . the functional deficits extension was 10 with preserved flexion at the last inspection six months after the accident . a main problem in the treatment of the patient with a clenched fist injury is uncompliance . during the period of the last ten years , we treated seven patients with deep clenched fist injury with npwt and almost all were non - compliant . the typical injury pattern of the clenched fist injury is tooth penetration of the dorsum of the hand over the third mp joint . in our case , patients usually initially did not seek medical attention for a little stab wound with no apparent local reactions . they looked for the help later , after the occurrence of the swelling and pain . the median interval between the bite and presentation was about 58  h. the patient visited our department two days after injury , with already developed clinical symptoms . during the surgical revision of the wound , there is often overlooked communication with the cavity of the joint because the hand is often revised in extension , but only revision in flexion demonstrates skin , tendon and joint sheaths in one line . in our case , during the first revision , we had seen the only partial damage to the extensor tendon . we were aware of the possibility of cartilage and bone penetration , but found no signs until mri revealed the overlying septic arthritis and osteomyelitis . septic arthritis and osteomyelitis are dangerous complications of fight bite because they are extremely difficult to eradicate and associated with a high risk of amputation and permanent joint stiffness . the management of clenched fist injury complicated by joint and bone infections remains a challenge . today , the accepted treatment of these injuries is an exploration of the wound with debridement and lavage . different solutions may be used for irrigation ( physiological saline , hydrogen peroxide , gentamicin ) . the literature also described the techniques such as cauterization with nitric acid . according to some studies , such wounds should be left to heal by secondary intention to avoid serious infectious complications.1 , 4 , 7 however , secondary healing and prolonged inflammation can impair wound healing and lead to marked scarring . npwt has been proven to be a reliable method to treat a diversity of wounds . the decrease in edema , removal of wound exudate with bacteria and microdeformations of the wound bed  clinically indicate the improved healing potential . npwt leads to increased local interleukin expression in the early phase of inflammation which may start accumulation of neutrophils and significantly decrease bacterial count . application of npwt  has a significant effect on local expression of vascular endothelial growth factor in acute traumatic wound , which seems to play a crucial role in the accelerated granulation tissue formation . the most frequently cultured bacteria are streptococcus , staphylococcus , e. corrodens , fusobacterium , peptostreptococcus and candida . streptococcus gordonii and gram - positive anaerobic species were isolated . in the clinical study and animal study , the vacuum sealing drainage leads to negative microbiological smears and decreased bacterial count.10 , 11 in our patient , we debrided the wound and used npwt and systemic antibiotics . therefore final negative bacteriological samples were more the impact of combined therapy , but npwt represented an important part of treatment , after which local findings were improved . each wound over the mp joints requires a thorough revision , debridement of damaged tissues and antibiotic prophylaxis . in diagnostic doubts , we believed that after surgical revision and wound debridement of clenched fist injury , npwt will enhance healing of infected wounds and avoid excessive joint stiffness of the hand .
we reported a 30 years old man who suffered a bite wound of the right hand in a fight . 
 two days after the injury , he was admitted in emergency because of stab wound above the head of the third metacarpal bone . 
 he presented the swelling , redness , pain and fever . 
 primary revision confirmed only partial lesion of the extensor apparatus . during the following days , we recorded a deterioration of local findings and magnetic resonance imaging revealed osteomyelitis and septic arthritis of the third metacarpophalangeal joint . 
 the wound was then revised several times using negative pressure wound therapy in combination with intravenous antibiotics . 
 after resolution of clinical and laboratory findings , the wound was finally closed by delayed primary suture . 
 clenched fist injury is a medical emergency that requires immediate surgical revision . 
 we treated clenched fist injury with the development of septic arthritis and osteomyelitis with negative pressure wound therapy and obtained good outcomes .