334
Injury, 12.334-339
Printedin GreatBritain
Pseudomonas osteomyelitis following puncture wounds of the foot in children S. Das De University Department
of Orthopaedics, Western Infirmary, Glasgow
T. A. McAllister Consultant Bateriologist, Royal Hospital for Sick Children and Queen Mother’s Hospital, Glasgow Summary
Four cases of pseudomonas osteomyelitis following puncture wounds of the foot in children are presented. The infections resolved after drainage of pus and treatment with gentamicin, to which the pseudomonas was sensitive. These kinds of infections are associated with inadequate wound care and since late diagnosis is associated with troublesome morbidity, it is important that casualty offtcers are aware of the condition. INTRODUCTION SIMPLE puncture
wounds are commonly seen in the accident and emergency departments of most hospitals. In 1968 Johanson reported 11 patients who had osteomyelitis caused by Pseudomonas aeruginosa after puncture wounds of the feet. Since then others have reported sporadic cases in paediatric journals (Feigin et al., 1970; Hagler, 1971; Minnefor et al., 1971) and more recently in orthopaedic journals (Brand and Black, 1974; Miller and Semian, 1975; Riegler and Routson, 1979). PATIENTS
AND
METHODS
Four patients with pseudomonas osteomyelitis at the site of puncture wounds of the foot were seen over a peiod of 8 years in the western half of Glasgow. Pus obtained from the puncture wounds was cultured in the following media: a, aerobic and anaerobic media of horse blood agar; b, DST agar medium; c, McConkey’s medium; d, Robertson’s meat liquid culture medium.
Pseudomonas aeruginosa was cultured from the wounds of all 4 patients and was sensitive to gentamicin. In 197 1, using doubling dilution methods, a range of 0.06-64 mg/l was used to detect the level and calculate the dosage of gentamicin. More recently, plate diffusion using wells cut in DST agar containing control sera, with measured amounts of gentamicin, was used to draw a regression line and the test result was derived from zone sizes measured on the same plate. How long gentamicin therapy should be continued is debatable. Two weeks is an average period (McAllister, 1974). CASE
REPORTS
Case 1 A I3-year-old boy presented with an obviously infected puncture wound of 2 weeks’ duration after a nail prick of the sole, adjacent to the second metatarsophalangeal joint. A swab from his wound was sent for culture and sensitivity. He was covered against tetanus by previous immunization. Radiographs did not reveal any foreign body or other abnormality. He was treated by local magnesium sulphate dressing, cloxacillin 250 mg 6-hourly, with rest in bed and elevation at home. Three days later his foot was still inflamed over the dorsum of the second metatarsophalangeal joint; there was marked tenderness in that area. His temperature was 36.6 “C, erythrocyte sedimentation rate 39 mm and white cell count 9800 with neutrophilia. Blood cultures did not produce any growth of organisms. Radiographs revealed destruction of the second metatarsal heads and of the base of the proximal phalanx of the second toe, consistent with osteitis
Das De and McAllister: Pseudomonas Osteomyelitis
Fig. 1. Case 1. Anteroposterior radiograph 14 days after injury showing osteolytic lesions of second metatarsal head and base of proximal phalanx of the second toe.
Fig. 2. Case 1. Anteroposterior radiograph at 4 months showing periosteal new bone and destruction of the second metatarsophalangeal joint.
(Fig. I). Wound swabs had produced a light growth of Staphylococcus albus and Pseudomonas aeruginosa, sensitive to gentamicin and tobramycin. Incision and drainage with curettage of the head of the second metatarsal and excision of the plantar wound were carried out. Two millilitres of light yellow pus were evacuated and yielded a heavy growth of Pseudomonas aeruginosa. The patient was given gentamicin 60 mg 8-hourly for five days, followed by tobramycin 40 mg I-hourly for a further two weeks, and he kept off the foot, using crutches. His wound healed but left him with a rather stiff second metatarsophalangeal joint. Radiographs four months later showed periosteal new bone and healed bony lesions (Fig. 2.). In spite of fibrous ankylosis of his second metatarsophalangeal joint, he was able to play football without any pain.
250 mg 6-hourly. He was advised to rest in bed and to elevate his foot at home. When he returned six days later his foot was still inflamed and tender but there was no systemic sign of infection. His wound was explored superficially and two pieces of gravel were removed. Culture showed a heavy growth of Staphylococcus albus and Pseudomonas aeruginosa, both organisms being sensitive to gentamicin, of which he was given 14 mg I-hourly by intramuscular injection, together with cloxacillin 500 mg 6-hourly. There was no improvement in his general condition. Cloxacillin was stopped twelve days later in the belief that its combination with gentamicin might be antagonistic in high doses (Noone and Pattison, 197 1). Further radiographs now showed a translucent area on the medial side of the body of the talus and the presence of a radio-opaque foreign body in the centre of the area (Fig. 3). Using a medial approach to the talus, a large cavity was found beneath its medial cortex. Large quantities of pus were evacuated from the talus and the ankle and subtalar joints. The adjacent articular cartilage was necrotic. A piece of rubber about 0.5 cm in diameter was extracted from the centre of the cavity. Culture of the pus yielded a heavy growth of Pseudomonas aeruginosa, sensitive
Case 2 A 6-year-old boy, wearing a pair of rubber shoes, fell on a metal spike when he was climbing a wall. He came to hospital with a puncture wound over the medial and plantar aspect of the middle of the right foot. Radiographs did not reveal any bony injuries or the presence of a foreign body. Toilet of his wound was carried out and he received tetanus toxoid and prophylactic ampicillin 500 mg and cloxacillin
336
Injury: the British Journal of Accident Surgery Vol. 1 Z/No.
4
Fig. 4. Case 2. Lateral radiograph after 5 months, showing irregularity of the posterior quarter of the body of the talus. No feature of avasuclar necrosis.
Fig. 3. Case 2. Anteroposterior and lateral radiographs 6 weeks after injury, showing translucent area in the medial side of the body of the talus and presence of a radio-opaque foreign body in the centre of the cavity. to gentamicin. The gentamicin dosage was doubled and finally quadrupled at 168 mg a day, but serial urine and serum gentamicin levels were low (1.25 mg/l). Peak levels were obtained 45 minutes after intramuscular injection of gentamicin; a trough was obtained just before the next injection. The minimal inhibitory concentration of the pseudomonas strain was 0.6 mg/l. Most strains of Pseudomonas aeruginosa have a minimal concentration for gentamicin of 0.5-2 mg/l. Throughout this period of gentamicin therapy there was no sign of toxicity. Auditory and vestibular nerve functions were not affected. After four weeks the erythrocyte sedimentation rate dropped to 11 mm and his wound healed. Gentamicin was stopped after a six-week course. At review after five months, the wound had remained healed, but there was a slight valgus deformity of the heel and foot. Radiographs showed further healing of the lesion in the talus with some irregularity of the posterior quarter of its body, but with no collapse of the body or evidence of avasuclar necrosis (Fig. 4). The patient was given a Whitman’s brace for his deformed heel. At review six months later, he was asymptomatic and his wound had remained healed but with a slight persistent valgus deformity ofthe heel. Case 3 A IO-year-old boy came to hospital with a glass puncture wound on the sole of his foot, over the second metatarsophalangeal joint that he had sustained two days previously. There was inflammation, but radiographs failed to reveal any abnormality. He received a booster dose of tetanus toxoid, an intramuscular injection of Triplopen and superficial wound toilet, and was advised to rest in bed and to elevate his foot at home. He was reviewed a week later and admitted. His erythrocyte sedimentation rate
was 60 mm but his temperature was normal. Blood cultures did not produce any growth of organisms. Radiographs now showed a lytic lesion in the head of the second metatarsal and base of the adjoining proximal phalanx. Two millilitres of pale yellow pus were removed on incision and drainage; the pus yielded a heavy growth of Pseudomonas aeruginosa in pure culture. The patient was given 40 mg of gentamicin 8-hourly for two weeks. At the end of this period the erythrocyte sedimentation rate dropped to 8 mm. Serial serum gentamicin levels were checked regularly. There was no evidence of gentamicin toxicity. By the fourth week the patient was beginning to bear weight and there was little pain or tenderness over the second metatarsophalangeal joint, which was slightly stiff. Radiographs showed reconstitution of the second matatarsal head and the base of the second proximal phalanx. Case 4 This case, of which the early result was reported by McKinnon in 1975, is presented again alter a long term review. An 1l-year-old boy attended with a puncture wound beneath the metatarsophalangeal joint of his right great toe which had been caused by a nail two days before. He was treated with local dressings, Triplopen and tetanus toxoid. After a brief initial improvement, the boy was seen a week later and radiographs did not reveal any abnormality. He was given a course of ampicillin and cloxacillin and advised to rest in bed. There was no improvement aher a few days and he was admitted. The erythrocyte sedimentation rate was 48 mm, white blood cellls numbered 7400 and the temperature was normal. Radiographs now showed destruction of the proximal ends of the proximal phalanx of the great toe and the head of the first metatarsal bone (Fig. 5). Incision and drainage yielded some thick pus. The cartilage of both the head of the first metatarsal and the base of the proximal phalanx was necrotic and curettage was carried out. Culture of the pus grew Pseudomonas aeruginosa sensitive to gentamicin, of which 40 mg were given I-hourly for five days. Inflammation settled and he was discharged home two weeks later which
Das De and McAllister: Pseudomonas Osteomyelitis
Fig. 5. Case 4. Anteroposterior radiograph 23 days after injury showing osteolytic lesion of the first metatarsal head and the base of proximal phalanx of the big toe. was after his wound had healed. Fourteen months later he was symptomless and playing games. A few months later he sustained a further injury of the same toe and came to hospital with pain and swelling over the first metatarsophalangeal joint. Radiographs revealed early degenerative changes in the first metatarsophalangeal joint (but no recent bony injury). Erythrocyte sedimentation rate was 6 mm. Even after a period on crutches he still had pain on attempting any passive movement of his stiff toe. He was observed at regular intervals for a further year. As persistent discomfort interfered with his sporting activities two and a half years after injury, he underwent Keller’s arthroplasty. In spite of this he continued to have pain and finally needed arthrodesis of his first metatarsophalangeal joint. Five years later, he was reviewed for trouble with his hand, but he had no pain in his foot and was able to participate in sports. DISCUSSION Puncture wounds
of the foot, especially in children, are a fairly common cause of attendance at accident and emergency departments of hospitals. The treatment usually instituted at the time of injury is superficial wound toilet, tetanus prophylaxis and an antibiotic chiefly against Gram positive organisms.
337
Of the four cases described, one patient presented himself on the day of injury, but the other three attended with inflammation or clinical infection 2-14 days from the time of the injury. The delay from the time of injury to diagnosis of Pseudomonas aeruginosa infection was from 12 to 4 1 days (Table Z). The punctures were on the sole. In two cases they underlay the second metatarsophalangeal joint; in one case it involved the first metatarsophalangeal joint and in the other it was over the plantomedial aspect of the middle of the foot. There was little systemic disturbance, with no fever nor elevation of the white cell count, but the erythrocyte sedimentation rate was elevated to 30-l 00 mm. Radiographs at 14 days in all four patients showed changes consistent with osteitis of the adjacent bones. Incision and drainage in all four patients produced a moderate to heavy growth of Pseudomonas aeruginosa with a light growth ofGram positive cocci in two cases. Earlier diagnosis is possible with bone scanning and xeroradiography of the soft tissues for non-metallic foreign objects (Riegler and Routson, 1979). In early cases, diagnosis can be achieved clinically even before the presence of pus by injecting and aspirating saline. The aspirate should be Gram stained and cultured in routine blood culture media (Miller and Semian 1975). The source of Pseudomonas aeruginosa in these infections was not established. It could have been introduced as a contaminant from the soil or from the skin of the foot. Miller and Semian (1975) cultured swabs from the interdigital spaces between the third and fourth toes of 100 active individuals of various socioeconomic and hygienic backgrounds but did not recover Pseudomonas aeruginosa in any of these cultures; others have found the organism in the skin (Marples, 1969). Foreign matter, not necessarily radio-opaque, introduced into the wound may have contributed towards the growth of the organism. It is not known why children have a special predisposition towards infection following puncture pseudomonas wounds. Somerville (1969) has observed that the normal skin flora of children frequently includes Gram negative organisms and this may be relevant. Gentamicin is the antibiotic most commonly used against pseudomonas infections. All four patients were treated with gentamicin intramuscularly with a dose of 2 mg per kg body weight g-hourly (McAllister, 1974). Serum gentamicin levels should be measured 24 hours after the first dose. In Case 2 the dose was
6
10
11
2
3
4
1st MTP
2nd MTP base
Medial aspect over talus
2nd MTP base
Site
Wound toilet, tetanus toxoid, elevation/rest, ampicillin, cloxacillin
Wound toilet, tetanus toxoid, elevation/rest, Triplopen Soaks, tetanus toxoid, elevation/ rest, Triplopen
Metal spike (introducing pieces of rubber and gravel)
Pieces of glass
Nail
Soaks, tetanus toxoid, elevation/ rest, cloxacillin
Initial treatment
Nail
Cause of injury
in 4 cases of pseudomonas
23
-.
-
-
-
--
.-
.--
-L
(3 weeks) Gentamicin (5 days)
Triplopen (3 days) Amoicillin
Cloxacillin (2 weeks) Gentamicin (5 days) Tobramycin (2 weeks) Amoicillin Cloxacillin (5 weeks) Cloxacillin and gentamicin (1 week) Gentamicin only further (5 weeks) Triplopen Gentamicin 12 weeks)
Antibiotics
_I-
-^
Operation
- -
- ~.
penicillin 475
a, I and D curettage b, Keller’s operation c, 1 st MTP joint fused
I and D curettage
I and D. later further I and D curettage cavity of talus. Removal of FB
I and D curettage
each vial contains benethamine
Pseudomonas aeruginosa (light growth)
Pseudomonas aeruginosa (profuse growth)
Staohvlococcus a/bus Pstkciomonas aeruginosa (profuse growth)
41
12
Staphylococcus a/bus Pseudomonas aeruginosa (profuse growth)
Culture
following puncture wounds
21
Delay in diagnosis of infection (days)
osteomyelitis
MTP, metatarsophalangeal joint; I and D, incision and drainage. Triplopen, 250 mg and sodium penicillin 6300 mg.
13
Age (vr)
1
Case
Table/. Summary of treatment
mg, procaine
penicillin
Stiff 2nd MTp joint Occasional discomfort at 4 months Pain and stiffness great toe Very mild symptom after fusion operation after 6 years
Valgus deformity of heel and foot Irregularity posterior talus at 9 months
Stiff 2nd MTP joint but no pain and playing football at 7 months
Sequelae
Das De and McAllister: Pseudomonas osteomyelitis
quadrupled to 168 mg per day but serum and urinary levels of gentamicin remained at such low levels (1.25 mg/l) that penetration of gentamicin into bone would be of doubtful efficacy. However, this particular strain was highly sensitive, which possibly explains the good clinical result despite the persistently low serum gentamicin level. There has been no recurrence or chronicity of the infection in this small series and this has also been the case with other observers (Brand and Black, 1974). Some impairment of activity resulting from stiffening of the affected joint has been a common feature in all the cases. Johanson (1968) attributes this to cartilage necrosis, which is also a typical feature of the pseudomonas osteomyelitis.
Acknowledgement
We wish to thank Mr G. A. Whitefteld, consultant orthopaedic surgeon at the Southern General Hospital, and the consultants at the Royal Hospital for Sick Children in Glasgow for advice and permission to study these cases. We also thank Professor Hamblen and Mr G. Waddell at the Western Infnmary for valuable advice in the preparation of this paper and to Miss R. A. McCall for secretarial assistance.
Requesfsjor reprinfs
339 REFERENCES
Brand R. A. and Black H. (1974) Pseudomonas osteomyelitis following puncture wounds in children. J. Bone Joint Surg. S6A, 1637. Feigin R. D., McAlister W. H., San Joaquin V. H. et al. (1970) Osteomyelitis of the calcaneous: Report ofeight cases. Am. J. Dis. Child. 119,61. Hagler D. J. (197 1) Pseudomonas osteomyelitis: puncture wounds of the foot. (Letter to the Editor.) Paediatrics 48,672.
Johanson P. D. (1968) Pseudomonas infections of the foot following puncture wounds. JAMA 204,262. McAllister T. A. (1974) Gentamicin in paediatrics. Postgrad. Med. J. SO,45. MacKinnon A. A. (1975) Pseudomonas osteomyelitis following puncture wounds. Postgrad. Med. J. 51, 33. Marples M. J. (1969) Life on the human skin. Sci. Am. 220,108. Miller E. H. and Semian D. W. (1975) Gramnegative osteomyelitis following puncture wounds ofthe foot. J. Bone Joint Surg. S7A, 535. Minnefor, A. B., Olson M. I. and Carver D. H. (197 1) Pseudomonas osteomyelitis following puncture wounds of the foot. Paediatrics 47,598. Noone P. and Pattison J. R. (197 1) Therapeutic implications of interactions of gentamicin and penicillins. Lancer 2,575. Riegler H. F. and Routson G. W. (1979) Complications of deep puncture wounds of the foot. J. Trauma 19,18. Somerville D. A. (1969) The effect of age on the normal bacterial flora of the skin. Br. J. Dermatol 81, Suppl. 1, p. 14.
should be addressed to: Mr S. Das De, Orthopaedic
Western Infirmary, Glasgow,
Gl 1 6NT.
Registrar, University Department
of Orthopaedics,