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Selective hepatic artery embolization in complex liver injury
Casereports
347 high- or low-density objects contribute corresponding density values, which when averaged with the rest of the structures in the volume result in abnormally high or low HU being assigned to the entire area. This is termed the partial volume effect. The effect may be minimized by using
Figure2. Axial CT scan through CZ showing retained air track with thin hyperdense
band on its medial aspect.
On subsequent exploration of the wound, an 80 x 5 x 3 mm splinter of wood was found extending from just below the skin into the spinal cord at 0; it was easily removed. Over the following weeks there was a partial improvement in the patient’s condition, but to date her upper limb has remained flaccid.
Discussion wooden splinter was scanned using the same as the original CT. It gave a reading in excess of ~ooHU and should theoretically have been clearly visible on standard CT windows. The reason it was not seen was the partial volume effect. The extracted
finer slice thicknesses to limit the volume included in each slice (Wegener, 1983). Although in this patient the CT slices had been only 3 mm thick, partial volume effect resulted in poor visualization of the denser foreign body lying as it did within the air track. Since in the normal course of events pockets of air are absorbed within days, a persistent air track should alert the clinician to the possibility of a foreign body. A detailed search for radiologically subtle foreign objects should always follow. Awareness of this may help avoid the pitfall created by the partial volume artefact, and encourage an active search using all available modalities to detect any inconspicuous object.
References Lipschitz R. and Block J. (1962) Stab wounds of the spina cord. Lancet 1,169. Peacock W. J., Shrosbree R. D. and Key A. G. (1977) A review of 450 stab wounds of the spinal cord. S. Afr. Med. 1. 51,961. Wegener 0. H. (1983)Whole Body Computerized Tomography. Berlin: Schering AG.
parameters
The value of Hounsfield unit (HU) assigned to a particular area is a mean value for the tissue contained in the volume of
the area. If the area contains structures of varying density, to the HU. Very each structure contributes proportionally
Paper accepted
4 November
1991.
Requests for reprints should be addressed to: Mr G. J. Oettlb, Department of Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa.
Selective hepatic artery embolization liver injury
in complex
I’. Corr”, S. J. Beningfield* and J. E. J. Krige+ Departments
of Radiology*
and Surgery+, University
of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
Introduction The liver is the most commonly injured organ in patients with blunt abdominal trauma (Feliciano, 1989). In the majority of liver injuries haemorrhage can be controlled by simple methods such as manual compression and ligation of accessible bleeding vessels within the liver wound. Patients who have major parenchymal or venous injuries require more advanced techniques for control of liver bleeding. Despite prompt resuscitation and operative intervention, haemorrhage and the risk of exsanguination increase in direct proportion to the severity of the injury. Mortality in complex liver injuries ranges from 30 per cent to 40 per cent with the majority of deaths being due to shock and 0 1992Butterworth-Heinemann 0020-1383/92/050347-02
Ltd
postoperative bleeding (Cogbill et al., 1988). Recent reports have documented the benefit of temporary perihepatic packing and planned relaparotomy in controlling haemorrhage in selected patients with major liver injuries. Packing does not, however, control bleeding with uniform success and the optimal management of recurrent bleeding in critically injured patients remains unresolved. Selective hepatic artery angiography and embolization has been useful in the detection and control of haemorrhage after liver injury (Scalafini and Ben-Menachem, 1989). We report the extended role of selective hepatic arteriography and embolization in the successful management of two patients with complex liver trauma and continued bleeding despite liver packing.
348
Injury: the British Journal of Accident Surgery (1992) Vol. 23/No.
Case reports CaSeI A 25-year-old
man was admitted to a peripheral hospital after a pedestrian motor vehicle accident with eight right rib fractures and a right haemothorax. A right intercostal chest drain was inserted after resuscitation. He developed abdominal pain and a high temperature 8 days later. Ultrasound demonstrated a large haematoma of the right lobe of the liver. At laparotomy an infected haematoma of the liver was evacuated. Major bleeding occurred from a deep stellate fracture of the right lobe of the liver. Visible vessels were ligated within the fracture. At 6 h postoperatively, further bleeding occurred from the liver which was controlled by perihepatic packing with abdominal gauze swabs. Recurrent bleeding 12 h later required a relaparotomy. After further packing failed to control the bleeding, the patient was transferred to our unit for evaluation. A selective angiogram showed active bleeding from a branch of the right hepatic artery (Figure IA). Embolization with gelfoam pledgelets produced occlusion of branches of the right hepatic artery (Figure IB). No further bleeding occurred. At laparotomy 3 days after embolization, abdominal swabs and 750 ml of blood clot in the subhepatic space were removed. After a protracted course requiring intensive care unit ventilation for adult respiratory distress syndrome, the patient was discharged well 5 weeks later. Repeat CT scan 10 weeks later
showed no residual haematoma. case2 A 26-year-old male sustained blunt abdominal trauma and a closed fracture of the right tibia and fibula during a motorcycle accident. On admission to hospital he was shocked, the blood pressure was 95130, pulse 12o/min and haemoglobin 9g per cent. The abdomen was distended and diagnostic peritoneal lavage was positive. At laparotomy a fracture of the right lobe of the liver with multiple stellate lacerations was found. A Pringle manoeuvre provided temporary control of bleeding, Accessible vessels in the liver wound were ligated. The patient received eight units of blood and four units of fresh frozen plasma. Continued liver bleeding was controlled with six abdominal packs and the abdomen was closed. Postoperatively, a dilutional coagulopathy was corrected with fresh frozen plasma, cryoprecipitate and a platelet infusion. The packs were removed in theatre 48 h after the initial injury. Major bleeding recurred and the liver was repacked and the abdomen closed. Selective hepatic artery angiography demonstrated bleeding from a branch of the right hepatic artery which was embolized with two Gianturo steel coils (FigureM,B). The packs were removed without further bleeding 48 h later. A CT scan (Figure 3) 1 week later demonstrated a small collection of gas in the right lobe of the liver which resolved spontaneously.
Figure 1. A, Selective hepatic arteriogram demonstrating active bleeding from a branch of the right hepatic artery (arrow). B,
Branch occluded with gelfoam pellets.
Needle aspiration and culture of the collection organisms or pus.
5
did not reveal
Discussion The judicious use of perihepatic packing to control bleeding in complex liver trauma, has evolved as an acceptable and recognized emergency measure over the past decade. Moore reported an overall 4 per cent incidence of perihepatic packing in civilian liver injuries treated at eight major North American regional trauma centres (Moore, 1984). In a survey of six North American regional trauma referral centres, 25 per cent of patients with major hepatic trauma required packing (Cogbill et al., 1988). Thrombocytopaenia, qualitative defects of platelet function and coagulopathy aggravated by shock, hypothermia and acidosis are common after massive rapid blood transfusion in major liver trauma. There is consensus that packing is the treatment of choice for transfusion-induced coagulopathy providing time to return the patient to the intensive care unit safely for further correction of coagulation abnormalities and hypothermia (Feliciano et al., 1986). When packing is used it is important to ensure effective uniform pressure, avoid caval compression, provide ventilatory support and remove the packs within 48 h to minimize the risk of sepsis and to make provision for dealing with recurrent bleeding. The technique does not replace conventional methods of haemostasis and has application only in selected cases with bleeding due to coagulopathy, the transfer of patients from peripheral hospitals to large centres of expertise, or as a life-saving manoeuvre in haemodynamitally unstable patients with extensive liver injuries in whom resection or further intervention would be hazardous (Terblanche and Krige, 1990). Therapeutic hepatic arteriography is an established interventional technique that is safe, effective and often lifesaving in complex liver injuries (Allison et al., 1985). The recurrent haemorrhage from deep in the liver parenchyma may be difficult to identify and control at laparotomy. Proximal right hepatic artery ligation may fail to control bleeding due to distal filling via collateral vessels (Feliciano et al., 1986). Superselective catheterization and embolization occludes only’the source of bleeding while sparing blood flow to normal parenchyma, in contrast to surgical ligation where technical considerations dictate more proximal ligation. As the liver has a dual blood supply, embolization of the hepatic artery is usually well tolerated provided the portal vein is normal and there is no hepatofugal flow as in
Figure 2. A, Selective hepatic arteriogram demonstrating bleeding from a branch of the right hepatic artery (arrow) embolized with two Gianturco coils (B).
Case reports
349
angiography and embolization provided safe and definitive control of haemorrhage in our two patients and is advocated in complex liver injury when bleeding recurs despite packing.
References
Figure 3. CT scan demonstrating embolization.
intrahepatic gas (arrow) after
cirrhosis. Portal vein patency must be established before embolization. Selective catheterization distal to the cystic artery is advisable to reduce the risk of gallbladder infarction (Takayasu et al., 1985). Embolic materials for selective occlusion include Gianturco coils and gelatin sponge pledgelets. Non-selective extensive embolization with small particles or alcohol may cause hepatic necrosis. Post-embolization syndrome comprising nausea, fever, leucocytosis and pain is commonly seen and may last for several days (Allison et al., 1985). Intrahepatic gas is commonly detected after hepatic embolization and appears to be a benign occurrence, probably due to oxygen released from trapped red blood cells in embolized vessels (Allison et al., 1985). Selective hepatic
Allison D. J., Jordon H. and Hennessy 0. (1985) Therapeutic embolisation of the hepatic artery: a review of 75 procedures. lancet 1,595 Cogbill T. H., Moore E. E., Jurkovich G. J, et al. (1988) Severe hepatic trauma: a multicentre experience with 1335 liver injuries. 1. Trauma 28,1433. Feliciano D. V. (1989) Surgery for liver trauma. Sttrg. C/in. North Am. 69,273. Feliciano D. V., Mattox K. L., Burch J. M. et al. (1986) Packing for control of hepatic haemorrhage. J. Trauma 26,738. Moore E. E. (1984) Critical decisions in the management of hepatic trauma. Am. 1. Swg. 148,712. Scalafini S. and Ben-Menachem Y. (1989)Embolotherapy in abdominal trauma. In: Neal M., Tsinado J. and Shao-Ru C. (eds) Emergency Inkruentional Radiology. Boston: Little Brown, 53. Takayasu K., Moriyama N., Muramatsu Y. et al. (1985)Gall bladder infarction after hepatic artery embolisation. Am. J Radial. 144,135. Terblanche J. and Krige J. E. J. (1990) Injuries to the liver and bile ducts. In: Williamson R. C. N. and Cooper M. J. (eds) Emergency Abdominal Stlrgery. London: Churchill Livingstone 21. Paper accepted
3 October
1991.
Requests for reprints should be adressd to: Dr J. E. J. Krige, Department of Surgery, University of Cape Town, Observatory 7925,Cape Town, South Africa.
Acute traumatic bowing of the radius in an adult B. S. Mody, M. L. Rawes, W. M. Harper and 0.0. Department
of Orthopaedics,
Introduction Acute traumatic bowing of the radius is extremely rare in adults, and is associated with a peculiar mechanism of injury. Manipulative correction is very difficult. Simple measures may prevent its occurrence in high-risk groups.
Case report A 21-year-old man was admitted to the Leicester Royal Infirmary after sustaining an injury to the right dominant forearm and arm. He was working on an industrial conveyer belt system when his fingertips were caught up in the belt, pulling in his whole upper limb and wrapping it around the metal roller. The whole process took a few seconds. The machine was stopped immediately, but it took a minute or so before his limb could be released. On examination, the forearm and arm were deformed. There was no neurovascular compromise. Radiographs revealed a transverse 0 1992 Butterworth-Heinemann 0020-1383/92/05034’+02
A. Oni
Leicester Royal Infirmary, Leicester, UK
Ltd
fracture of the middle third of the shaft of humerus, a short oblique fracture of the lower third of the shaft of ulna and 25" dorsal bowing of the shaft of radius (Figure I). Comparative radiographs of the normal side showed the radial bow to be 6” dorsally (Figtire 2). The radioulnar joints were intact. Under general anaesthesia, an attempt was made to correct the bowing of the radius manually, but this was unsuccessful, The ulna was plated and, subsequent to this, it was found that the lower end dislocated dorsally on pronation, but it relocated on supination. Further attempts to correct the radial bow completely failed despite using considerable force. The check radiographs revealed a postmanipulation bow of 15”. The limb was put in an above-elbow hanging plaster cast with the forearm in midpronation. At 3 months, ulnar and humeral fractures were healed. Radiologically, there was no periosteal reaction in the radius. Now, movement beyond midpronation is restricted, while supination is only terminally restricted.
347 high- or low-density objects contribute corresponding density values, which when averaged with the rest of the structures in the volume result in abnormally high or low HU being assigned to the entire area. This is termed the partial volume effect. The effect may be minimized by using
Figure2. Axial CT scan through CZ showing retained air track with thin hyperdense
band on its medial aspect.
On subsequent exploration of the wound, an 80 x 5 x 3 mm splinter of wood was found extending from just below the skin into the spinal cord at 0; it was easily removed. Over the following weeks there was a partial improvement in the patient’s condition, but to date her upper limb has remained flaccid.
Discussion wooden splinter was scanned using the same as the original CT. It gave a reading in excess of ~ooHU and should theoretically have been clearly visible on standard CT windows. The reason it was not seen was the partial volume effect. The extracted
finer slice thicknesses to limit the volume included in each slice (Wegener, 1983). Although in this patient the CT slices had been only 3 mm thick, partial volume effect resulted in poor visualization of the denser foreign body lying as it did within the air track. Since in the normal course of events pockets of air are absorbed within days, a persistent air track should alert the clinician to the possibility of a foreign body. A detailed search for radiologically subtle foreign objects should always follow. Awareness of this may help avoid the pitfall created by the partial volume artefact, and encourage an active search using all available modalities to detect any inconspicuous object.
References Lipschitz R. and Block J. (1962) Stab wounds of the spina cord. Lancet 1,169. Peacock W. J., Shrosbree R. D. and Key A. G. (1977) A review of 450 stab wounds of the spinal cord. S. Afr. Med. 1. 51,961. Wegener 0. H. (1983)Whole Body Computerized Tomography. Berlin: Schering AG.
parameters
The value of Hounsfield unit (HU) assigned to a particular area is a mean value for the tissue contained in the volume of
the area. If the area contains structures of varying density, to the HU. Very each structure contributes proportionally
Paper accepted
4 November
1991.
Requests for reprints should be addressed to: Mr G. J. Oettlb, Department of Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa.
Selective hepatic artery embolization liver injury
in complex
I’. Corr”, S. J. Beningfield* and J. E. J. Krige+ Departments
of Radiology*
and Surgery+, University
of Cape Town and Groote Schuur Hospital, Cape Town, South Africa
Introduction The liver is the most commonly injured organ in patients with blunt abdominal trauma (Feliciano, 1989). In the majority of liver injuries haemorrhage can be controlled by simple methods such as manual compression and ligation of accessible bleeding vessels within the liver wound. Patients who have major parenchymal or venous injuries require more advanced techniques for control of liver bleeding. Despite prompt resuscitation and operative intervention, haemorrhage and the risk of exsanguination increase in direct proportion to the severity of the injury. Mortality in complex liver injuries ranges from 30 per cent to 40 per cent with the majority of deaths being due to shock and 0 1992Butterworth-Heinemann 0020-1383/92/050347-02
Ltd
postoperative bleeding (Cogbill et al., 1988). Recent reports have documented the benefit of temporary perihepatic packing and planned relaparotomy in controlling haemorrhage in selected patients with major liver injuries. Packing does not, however, control bleeding with uniform success and the optimal management of recurrent bleeding in critically injured patients remains unresolved. Selective hepatic artery angiography and embolization has been useful in the detection and control of haemorrhage after liver injury (Scalafini and Ben-Menachem, 1989). We report the extended role of selective hepatic arteriography and embolization in the successful management of two patients with complex liver trauma and continued bleeding despite liver packing.
348
Injury: the British Journal of Accident Surgery (1992) Vol. 23/No.
Case reports CaSeI A 25-year-old
man was admitted to a peripheral hospital after a pedestrian motor vehicle accident with eight right rib fractures and a right haemothorax. A right intercostal chest drain was inserted after resuscitation. He developed abdominal pain and a high temperature 8 days later. Ultrasound demonstrated a large haematoma of the right lobe of the liver. At laparotomy an infected haematoma of the liver was evacuated. Major bleeding occurred from a deep stellate fracture of the right lobe of the liver. Visible vessels were ligated within the fracture. At 6 h postoperatively, further bleeding occurred from the liver which was controlled by perihepatic packing with abdominal gauze swabs. Recurrent bleeding 12 h later required a relaparotomy. After further packing failed to control the bleeding, the patient was transferred to our unit for evaluation. A selective angiogram showed active bleeding from a branch of the right hepatic artery (Figure IA). Embolization with gelfoam pledgelets produced occlusion of branches of the right hepatic artery (Figure IB). No further bleeding occurred. At laparotomy 3 days after embolization, abdominal swabs and 750 ml of blood clot in the subhepatic space were removed. After a protracted course requiring intensive care unit ventilation for adult respiratory distress syndrome, the patient was discharged well 5 weeks later. Repeat CT scan 10 weeks later
showed no residual haematoma. case2 A 26-year-old male sustained blunt abdominal trauma and a closed fracture of the right tibia and fibula during a motorcycle accident. On admission to hospital he was shocked, the blood pressure was 95130, pulse 12o/min and haemoglobin 9g per cent. The abdomen was distended and diagnostic peritoneal lavage was positive. At laparotomy a fracture of the right lobe of the liver with multiple stellate lacerations was found. A Pringle manoeuvre provided temporary control of bleeding, Accessible vessels in the liver wound were ligated. The patient received eight units of blood and four units of fresh frozen plasma. Continued liver bleeding was controlled with six abdominal packs and the abdomen was closed. Postoperatively, a dilutional coagulopathy was corrected with fresh frozen plasma, cryoprecipitate and a platelet infusion. The packs were removed in theatre 48 h after the initial injury. Major bleeding recurred and the liver was repacked and the abdomen closed. Selective hepatic artery angiography demonstrated bleeding from a branch of the right hepatic artery which was embolized with two Gianturo steel coils (FigureM,B). The packs were removed without further bleeding 48 h later. A CT scan (Figure 3) 1 week later demonstrated a small collection of gas in the right lobe of the liver which resolved spontaneously.
Figure 1. A, Selective hepatic arteriogram demonstrating active bleeding from a branch of the right hepatic artery (arrow). B,
Branch occluded with gelfoam pellets.
Needle aspiration and culture of the collection organisms or pus.
5
did not reveal
Discussion The judicious use of perihepatic packing to control bleeding in complex liver trauma, has evolved as an acceptable and recognized emergency measure over the past decade. Moore reported an overall 4 per cent incidence of perihepatic packing in civilian liver injuries treated at eight major North American regional trauma centres (Moore, 1984). In a survey of six North American regional trauma referral centres, 25 per cent of patients with major hepatic trauma required packing (Cogbill et al., 1988). Thrombocytopaenia, qualitative defects of platelet function and coagulopathy aggravated by shock, hypothermia and acidosis are common after massive rapid blood transfusion in major liver trauma. There is consensus that packing is the treatment of choice for transfusion-induced coagulopathy providing time to return the patient to the intensive care unit safely for further correction of coagulation abnormalities and hypothermia (Feliciano et al., 1986). When packing is used it is important to ensure effective uniform pressure, avoid caval compression, provide ventilatory support and remove the packs within 48 h to minimize the risk of sepsis and to make provision for dealing with recurrent bleeding. The technique does not replace conventional methods of haemostasis and has application only in selected cases with bleeding due to coagulopathy, the transfer of patients from peripheral hospitals to large centres of expertise, or as a life-saving manoeuvre in haemodynamitally unstable patients with extensive liver injuries in whom resection or further intervention would be hazardous (Terblanche and Krige, 1990). Therapeutic hepatic arteriography is an established interventional technique that is safe, effective and often lifesaving in complex liver injuries (Allison et al., 1985). The recurrent haemorrhage from deep in the liver parenchyma may be difficult to identify and control at laparotomy. Proximal right hepatic artery ligation may fail to control bleeding due to distal filling via collateral vessels (Feliciano et al., 1986). Superselective catheterization and embolization occludes only’the source of bleeding while sparing blood flow to normal parenchyma, in contrast to surgical ligation where technical considerations dictate more proximal ligation. As the liver has a dual blood supply, embolization of the hepatic artery is usually well tolerated provided the portal vein is normal and there is no hepatofugal flow as in
Figure 2. A, Selective hepatic arteriogram demonstrating bleeding from a branch of the right hepatic artery (arrow) embolized with two Gianturco coils (B).
Case reports
349
angiography and embolization provided safe and definitive control of haemorrhage in our two patients and is advocated in complex liver injury when bleeding recurs despite packing.
References
Figure 3. CT scan demonstrating embolization.
intrahepatic gas (arrow) after
cirrhosis. Portal vein patency must be established before embolization. Selective catheterization distal to the cystic artery is advisable to reduce the risk of gallbladder infarction (Takayasu et al., 1985). Embolic materials for selective occlusion include Gianturco coils and gelatin sponge pledgelets. Non-selective extensive embolization with small particles or alcohol may cause hepatic necrosis. Post-embolization syndrome comprising nausea, fever, leucocytosis and pain is commonly seen and may last for several days (Allison et al., 1985). Intrahepatic gas is commonly detected after hepatic embolization and appears to be a benign occurrence, probably due to oxygen released from trapped red blood cells in embolized vessels (Allison et al., 1985). Selective hepatic
Allison D. J., Jordon H. and Hennessy 0. (1985) Therapeutic embolisation of the hepatic artery: a review of 75 procedures. lancet 1,595 Cogbill T. H., Moore E. E., Jurkovich G. J, et al. (1988) Severe hepatic trauma: a multicentre experience with 1335 liver injuries. 1. Trauma 28,1433. Feliciano D. V. (1989) Surgery for liver trauma. Sttrg. C/in. North Am. 69,273. Feliciano D. V., Mattox K. L., Burch J. M. et al. (1986) Packing for control of hepatic haemorrhage. J. Trauma 26,738. Moore E. E. (1984) Critical decisions in the management of hepatic trauma. Am. 1. Swg. 148,712. Scalafini S. and Ben-Menachem Y. (1989)Embolotherapy in abdominal trauma. In: Neal M., Tsinado J. and Shao-Ru C. (eds) Emergency Inkruentional Radiology. Boston: Little Brown, 53. Takayasu K., Moriyama N., Muramatsu Y. et al. (1985)Gall bladder infarction after hepatic artery embolisation. Am. J Radial. 144,135. Terblanche J. and Krige J. E. J. (1990) Injuries to the liver and bile ducts. In: Williamson R. C. N. and Cooper M. J. (eds) Emergency Abdominal Stlrgery. London: Churchill Livingstone 21. Paper accepted
3 October
1991.
Requests for reprints should be adressd to: Dr J. E. J. Krige, Department of Surgery, University of Cape Town, Observatory 7925,Cape Town, South Africa.
Acute traumatic bowing of the radius in an adult B. S. Mody, M. L. Rawes, W. M. Harper and 0.0. Department
of Orthopaedics,
Introduction Acute traumatic bowing of the radius is extremely rare in adults, and is associated with a peculiar mechanism of injury. Manipulative correction is very difficult. Simple measures may prevent its occurrence in high-risk groups.
Case report A 21-year-old man was admitted to the Leicester Royal Infirmary after sustaining an injury to the right dominant forearm and arm. He was working on an industrial conveyer belt system when his fingertips were caught up in the belt, pulling in his whole upper limb and wrapping it around the metal roller. The whole process took a few seconds. The machine was stopped immediately, but it took a minute or so before his limb could be released. On examination, the forearm and arm were deformed. There was no neurovascular compromise. Radiographs revealed a transverse 0 1992 Butterworth-Heinemann 0020-1383/92/05034’+02
A. Oni
Leicester Royal Infirmary, Leicester, UK
Ltd
fracture of the middle third of the shaft of humerus, a short oblique fracture of the lower third of the shaft of ulna and 25" dorsal bowing of the shaft of radius (Figure I). Comparative radiographs of the normal side showed the radial bow to be 6” dorsally (Figtire 2). The radioulnar joints were intact. Under general anaesthesia, an attempt was made to correct the bowing of the radius manually, but this was unsuccessful, The ulna was plated and, subsequent to this, it was found that the lower end dislocated dorsally on pronation, but it relocated on supination. Further attempts to correct the radial bow completely failed despite using considerable force. The check radiographs revealed a postmanipulation bow of 15”. The limb was put in an above-elbow hanging plaster cast with the forearm in midpronation. At 3 months, ulnar and humeral fractures were healed. Radiologically, there was no periosteal reaction in the radius. Now, movement beyond midpronation is restricted, while supination is only terminally restricted.