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Fat embolism following prosthetic replacement of the femoral head
Volume 3 Number 2
DANDY" FAT EMBOLISM AFTER FEMORAL HEAD REPLACEMENT
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FAT E M B O L I S M FOLLOWING PROSTHETIC REPLACEMENT OF THE FEMORAL HEAD D. J. D A N D Y
Watford General Hospital
Four patients are described in whom cardiac arrest occurred between 2 and 5 minutes after placing acrylic cement in the femoral shaft during the insertion of a Thompson hip prosthesis for subcapital fracture of the neck of the femur. Two of the patients died, in both of whom post-mortem examination showed petechial haemorrrhages on the visceral pleurae and histological examination showed massive pulmonary fat embolism with fat globules in the capillaries. The other two patients were successfully resuscitated and developed a pyrexia after operation which lasted 4 days; their chest radiographs showed bilateral diffuse mottling consistent with pulmonary fat embolism. A possible cause for the fat embolism is suggested. INTRODUCTION IN one year at the Watford General Hospital, 22 Thompson hip prostheses were inserted for subcapital fracture of the neck of the femur; 4 patients suffered cardiac arrest during the operation. The average age of the 4 patients suffering cardiac arrest was 79.5 years, compared with an average age of 76.6 years in the whole group. During the same year 32 total hip replacements were inserted for osteo-arthritis. No patient in this group, the average age of which was 63.75 years, suffered cardiac arrest. Five patients suffering cardiac arrest after the insertion of acrylic bone cement into the femoral shaft have recently been reported (Burgess, 1970; Hyland and Robbins, 1970; Powell, McGrath, Lahiri, and Hill, 1970; Gresham, Kuczyfiski, and Rosborough, 1971), in three of whom (Burgess, 1970; Hyland and Robbins, 1970; Gresham and others, 1971) pulmonary fat embolism was demonstrated on histological examination of post-mortem material. All occurred after the insertion of Thompson hip prostheses for subcapital fracture of the femoral neck, and none followed total hip replacement.
through a posterior incision, using C.M.W. cement* containing barium sulphate, which was used in all the patients. She was considered unfit for operation on both hips at once. A Steinmann's pin was therefore passed through the left tibia and axial traction applied to the limb. She made an uninterrupted recovery from this operation. However, 5 weeks later it was apparent that bony union was not occurring in the left femur. A Thompson prosthesis was inserted through an anterolateral approach to the left hip. Premedication of Valium (diazepam) 5 nag. and atropine 0.6 nag. was given 45 minutes before operation and anaesthesia induced with methohexitone 90 rag. The patient was intubated after injecting Scoline (suxamethonium chloride) 50 rag. The patient's condition was satisfactory until approximately 5 minutes after placing acrylic cement in the femoral shaft, when the patient's bloodpressure became unrecordable and spontaneous respiration ceased. External cardiac massage and ventilation with pure oxygen was commenced. After 30 min. E.C.G. showed no ventricular complexes and resuscitation was discontinued. Routine post-mortem examinationshowed petechial haemorrhages over the visceral pleurae and histological examination of frozen sections of lung stained with scharlach R showed massive pulmonary fat emboli with fat globules in the pulmonary capillaries. Frozen sections of brain stained with scharlach R were examined microscopically, but no fat emboli were found. No petechiae were visible on macroscopic examination of the skin.
CASE REPORTS Case 1 An 87-year-old woman sustained bilateral femoral neck fractures in an epileptic fit. Two days after admission to hospital she received a transfusion of packed red blood-cells and 8 days after admission a Thompson prosthesis was fixed into the right femur,
Case 2 An 80-year-old woman fell at home, sustaining a subcapital fracture of the right femoral neck. She was * C.M.W. Bone Cement, C.M.W. Laboratories Ltd., Preston New Road, Blackpool.
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I N J U R Y ." T H E BRITISH J O U R N A L OF A C C I D E N T SURGERY
obese and suffered from diabetes mellitus, which was controlled by a low carbohydrate diet. Before the accident she could just manage to climb a flight of stairs but was prevented from doing more by dyspnoea. She was not receiving treatment for this condition. Clinical examination did not reveal evidence of congestive cardiac failure. Having decided to treat the fracture conservatively, Hamilton Russell traction was applied to the right lower limb. The patient could not tolerate this form of treatment and it was decided to insert a Thompson hip prosthesis 2 days after admission to hospital. Premedication of Valium (diazepam) 10mg. and atropine 0"6 mg. was given. Anaesthesia was induced with thiopentone and maintained with halothane; Scoline (suxamethonium chloride) was given to permit endotracheal intubation. Her condition was satisfactory for the first 30 min. after induction of anaesthesia when, 2 minutes after insertion of the cement, the anaesthetist noticed tachypnoea for approximately 30 sec. before a precipitous drop in bloodpressure occurred. The pulse and blood-pressure became recordable after administering pure oxygen and lowering the head of the operating table. The operation was then concluded uneventfully. The patient was anaesthetized for a total of 65 minutes when the patient's pulse became irregular and ventricular fibrillation supervened. Defibrillation produced asystole, but fibrillation recurred. Further defibrillation restored a normal complex for a short period but the pulse became more irregular and could not be restored to normal. Attempts at resuscitation were abandoned 45 min. after dosing the wound. At post-mortem there were petechial haemorrhages on the visceral pleurae of both lungs, and microscopic examination of frozen sections of lung stained with scharlach R showed evidence of massive pulmonary fat embolism with fat globules in the pulmonary capillaries. There was also an ante-mortem thrombus lodged in the artery supplying the upper lobe of the left lung. A few fat globules were demonstrated histologically in the glomeruli of both kidneys. Case 3 A n 80-year-old woman fell in her garden and sustained a subcapital fracture of the right femoral neck. For many years she had suffered from dyspnoea and occasional anginal pain on exertion. She had been receiving digoxin 0.25 mg. b.d. and Lasix (frusemide) 40 mg. on alternate days before admission and this was continued in hospital. On examination there were no signs of congestive cardiac failure although she was found to have atrial fibrillation. Two days after admission to hospital a Thompson prosthesis was inserted into the right femoral shaft. A premedieation of atropine 0"6 rag. was given thirty minutes before operation and anaesthesia was induced with thiopentone and maintained with halothane. Scoline (suxamethonium chloride) was injected before intubation and relaxation maintained with curare. A Thompson prosthesis was inserted 45 min. after induction of anaesthesia, using an anterolateral approach to the hip. One minute after inserting the prosthesis and 3 min. after starting to insert the acrylic cement the pulse and blood-pressure became unrecordable but returned after a further 2 rain.; after 5 min. the systolic blood-pressure was 100 ram. Hg. The patient's lungs were ventilated with pure oxygen and the head of the operating table lowered as soon as the cardiac arrest occurred. The
Injury
Oct. 1971
operation was concluded uneventfully with a total anaesthetic time of 1 hr. 10 min. The patient made a slow but steady recovery and was discharged home 5 weeks after operation. She had a pyrexia of 99 ° F. for 4 days after operation and a chest radiograph 17 days after operation showed diffuse mottling of both lung fields. The lungs had a normal radiological appearance on the day before operation. These radiological changes were consistent with a diagnosis of fat embolism or of bronchopneumonia. The radiological appearance of the lung fields had returned to normal 30 days after operation. Case 4 A 71-year-old man fell off his chair, sustaining a subcapital fracture of the left femoral neck. Before the accident he was unable to walk more than about 100 yards because of dyspnoea, and suffered occasional orthopnoea at night. He had received no treatment for his condition before the accident but was given digoxin 0.25 mg. b.d., Lasix (frusemide) 40mg. daily, and aminophylline suppositories at night before operation. There was no evidence of congestive cardiac failure on admission to hospital and 2 days later a Thompson prosthesis was inserted in the left femur. Premedication of Valium (diazepam) 10rag. and atropine 0.6 rag. was given. Anaesthesia was induced with methohexitone and maintained with halothane. Scoline (suxathoniurn chloride) 50 mg. was given to permit endotracheal intubation. The procedure was uneventful until 45 rain. after induction of the anaesthetic, which corresponded to 3 min. after the acrylic was placed in the shaft of the femur, when the pulse and blood-pressure became uurecordable and spontaneous respiration ceased. The patient was tilted head down, pure oxygen administered, and 100 ml. of 8-4 per cent sodium bicarbonate given intravenously. The pulse and blood-pressure could be recorded after 2 minutes and the patient made a steady recovery. After operation he had a pyrexia of 100-101 ° F. for 4 days and a chest radiograph showed patchy consolidation throughout both lung fields, which had resolved 4 weeks after operation. The radiographic changes were consistent with fat embolism or bronchopneumonia. At no time were petechiae observed on the skin. He made a slow recovery from operation.
DISCUSSION This p a p e r r e p o r t s a series o f 22 consecutive o p e r a t i o n s for subcapital f r a c t u r e of the femoral neck in w h i c h a T h o m p s o n prosthesis was fixed into the f e m u r with acrylic cement. In 4 o f these patients cardiac arrest occurred d u r i n g the o p e r a t i o n ; 2 p a t i e n t s could n o t be resuscitated a n d massive p u l m o n a r y fat e m b o l i s m was f o u n d at p o s t - m o r t e m e x a m i n a t i o n . T w o surviving patients h a d a pyrexia after operation, with changes o n the chest r a d i o g r a p h consistent with b r o n c h o p n e u m o n i a , b u t it is possible t h a t t h e radiological changes were due to fat embolism. Petechiae were n o t seen o n the skin o f a n y patient. N o cardiac arrest occurred d u r i n g 32 consecutive total hip r e p l a c e m e n t operations f~r
Volume 3 Number 2
D A N D Y " FAT EMBOLISM AFTER FEMORAL HEAD REPLACEMENT
degenerative joint disease performed during the same period. Gresham and others (1971) have reported that of 32 patients with femoral neck fractures treated by Thompson replacement arthroplasty using acrylic cement, 1 died immediately the prosthesis was inserted; in this patient and in 4 others who died within 36 hours of the same procedure, massive pulmonary fat embolism was demonstrated at post-mortem. Danckwardt-Lilliestrom, Lorenzi, and Olerud (1970) have shown that after reaming the tibial shaft of rabbits, fat globules are found in increased numbers in the vessels of the Haversian canals and under the periosteum; they found this to be caused by a rise in intramedullary pressure during reaming. While reaming of the femoral shaft alone may give rise to pulmonary fat emboli, it is possible that the forced insertion of acrylic cement temporarily increases the number of fat globules entering the circulation and arriving in the lung. Cardiac arrest occurred in all 4 patients reported here within 5 min. of insertion of the acrylic cement. It is not universally agreed that fat in the pulmonary capillaries is itself of clinical significance. Emson (1958) found fat in the pulmonary capillaries of 89 per cent of patients undergoing post-mortem examination after death from trauma. Other writers (Vance, 1931; Warren, 1946; Scully, 1956; Sevitt, 1966) have made similar reports, and many (Armin and Grant, 1951; Grant and Reeve, 1951; Scully, 1956) believe that pulmonary fat emboli are usually harmless. Pulmonary and cerebral fat embolism are reported in patients who died after external cardiac massage without other history of trauma (Jackson and Greendyke, 1965). The presence of massive pulmonary fat embolism at post-mortem examination with no other abnormality is not proof that fat embolism was the sole cause of death. Several causes have been suggested for cardiac arrest following the use of acrylic cement, including absorption of the monomer, air or fat embolism (Burgess, 1970; Harris, 1970; Hyland and Robbins, 1970; Gresham and others, 1971), and heat generated by the acrylic as it polymerizes (Durbin, Jeffery, Blundell Jones, Ling, Scott, Woodyard, and Wrighton, 1970). The approach to the hip, the position of the patient during operation, and the depth of anaesthesia could also be important. There may be interaction between one of the constituents of the acrylic cement and drugs given before operation to improve the patient's cardiac state, or with drugs given during operation. Few reports give
87
sufficient technical or clinical detail to permit further investigation. The femoral shafts of the patients reported here were not ' vented ', either by placing a cannula clown the femoral shaft or by drilling a small hole in the femoral cortex before insertion of the acrylic. Care was taken that acrylic was not inserted until it was as firm as could conveniently be handled, or before all odour of monomer had dispersed. It is noticeable that neither in this study nor in the recent reports (Burgess, 1970, Durbin and others, 1970; Frost, 1970; Harris, 1970; Hyland and Robbins, 1970; Powell and others, 1970; Gresham and others, 1971) has cardiac arrest been reported in patients undergoing total hip replacement for degenerative joint disease. There are several possible explanations for this apparent difference between the frequency of cardiac arrest after prosthetic replacement of the upper femur for fracture, and after replacement for degenerative joint disease. It may be that pulmonary fat emboli caused by fracture of the femoral neck render the lungs in some way more sensitive to further fat embolism occurring at the time of operation, to monomer or any other constituent of acrylic cement, or to some vaso-active substance released from bone or marrow by the heat of polymerization. Other differences exist between patients undergoing Thompson replacement arthroplasty and total hip replacement. Total hip replacement tends to be performed on patients who are both younger and fitter than those who sustain a subcapital fracture of the femoral neck. The average age of the 32 patients in this series who underwent total hip replacement was 63.75 years and the average age of those patients suffering cardiac arrest was 79-5 years. The latter patients would probably have been considered unfit for total hip replacement, had it been indicated clinically, because of their poor cardiorespiratory reserve. It is possible that the femoral neck adjacent to an osteo-arthritic hip differs from a fractured femoral neck in some way which renders pulmonary fat embolism less likely to occur after the insertion of acrylic. There is evidence (Phillips, 1966) that the pattern of venous drainage of the upper end of the femur in osteo-arthritis is different from that observed in patients who have sustained a fracture of the femoral neck. It is common experience that the femoral neck below an osteo-arthritic hip is harder and thicker than a femoral neck which has sustained a subcapital fracture; and that a fracture next to an osteoarthritic hip is a rarity.
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INJURY" THE BRITISH JOURNAL OF ACCIDENT SURGERY
A prospective study is needed to examine the venous blood for fat embolism in patients undergoing prosthetic replacement at the hip. Acknowledgements Thanks are due to Mr. A. Benjamin and Mr. K. I. Nissen for allowing me to study their patients, and to Professor R. G. Burwell for his helpful criticism during the preparation of this paper. REFERENCES ARMIN, J., and GRANT, R. T. (1951), 'Observations on Gross Pulmonary Fat Embolism in Man and the Rabbit ', Clin. Sci., 10, 442. BURGESS,D. M. (1970), Letter, Br. reed. J., 3, 588. DANCKWARDT-LILLIESTROM,G., LORENZI, G. L., and OLERtrO, S. (1970), 'Intramedullary Nailing after Reaming ', Acta orthop, scand., 134. DURBIN, F. C., JEFFERY, C. C., BLUNDELLJONES, G., LING, R. S. M., SCOTT, P. J., WOODYARD,J. E., and WRIGHTON, J. E. (1970), Letter, Br. reed. J., 4, 176. EMSON, H. E. (1958), ' Fat Embolism studied in 100 Patients dying after Injury ', J. clin. Path., 11, 28. FROST, P. M. (1970), Letter, Br. reed. J., 3, 524.
Injury Oct. 1971
GRANT, R. T., and REEVE,E. B. (1951), ' Observations on the General Effects of Injury in Man ', Spec. Rep. Ser. reed. Res. Court., No. 277. GRESHAM, G. A., KUCZYI~ISKI,A., and ROSBOROUGH, D. (1971), ' Fatal Fat Embolism following Replacement Arthroplasty for Transcervical Fractures of the Femur ', Br. reed. J., 2, 617. HARRIS, N. H. (1970), Letter, Ibid., 3, 523. HYLAND, J., and ROBmNS, R. H. C. (1970), Letter, Ibid., 4, 176. JACKSON, C. T., and GREENDYKE, R. i . (1965), 'Pulmonary and Cerebral Fat Embolism after Closed Chest Cardiac Massage ', Surgery Gynec. Obstet., 120, 25. PHILLIPS, R. S. (1966), 'Phlebography in Osteoarthritis of the Hip ', J. Bone Jt Surg., 48B, 280. POWELL, J. N., MCGRATH, P. J., LAHIRI, S. K., and HILL, P. (1970), 'Cardiac Arrest associated with Bone Cement ', Br. reed. J., 3, 326. SCULLY, R. E. (1956), ' F a t Embolism in Korean Battle Casualties ', Am. J. Path., 32, 379. SEVtTT, S. (1966), ' T h e Boundaries Between Physiology, Pathology and Irreversibility after Injury ', Lancet, 2, 1203. VANCE, B. M. (1931), ' T h e Significance of Fat Embolism ', Archs Surg., Chicago, 23, 426. WARREN, S. (1946), ' Fat Embolism ', Am. J. Path., 22, 69.
Requestsfor reprints should be addressed to:--D. 2. Dandy, Esq., F.R.C.S., Orthopaedic Department, St. Bartholomew's Hospital, West Smithfield,London E.C.I.
ABSTRACTS
FRACTURES AND DISLOCATIONS Fracture-dislocation of the Shoulder with Intrathoracic Displacement of the Head of the Humerus Stableforth, Ayres, and Taylor record this rare complication (3 previous cases reported in the literature) of fracture-dislocation of the shoulder with penetration of the chest wall by the head of the humerus with haemopneumothorax. Hypotension was corrected by intravenous infusion and an underwater seal drainage was set up. Recurrence of hypotensionwhile stereo-radiographs were being taken failed to respond to transfusion. Therefore, thoracotomy was performed. The head of the humerus was removed and a massive haemothorax was found, probably from torn intercostal vessels. There was a laceration of lung tissue. The intercostal vessels to the second, third, fourth, and fifth intercostal spaces were ligated, the lung tear was sutured, and chest drains inserted. The patient recovered but did not develop active shoulder function. STABLEFORTH,P. G., AYRES, P., and TAYLOR,G. A. (1971), ' Fracture Dislocation of the Upper Humerus into the Thoracic Cavity ', Can. J. Surg., 14, 235. Fractured Femur with Sciatic Palsy Drs. Neer, Grantham, and Foster from New York and Dr. Aufranc from Boston discuss the problem of a 4-year-old boy with fractures of both femoral shafts,
one being complicated by a sciatic palsy. There were several important points in the discussion worthy of attention. All the speakers agreed that early operative exploration was to be avoided and plate fixation at this early age was contra-indicated. This example proved to be the exception, and operation was performed early because (a) the ecchymosis and ease of palpation of the end of one of the fragments indicated that the deep fascia had been perforated; (b) manipulation under anaesthesia failed to demonstrate crepitus; (c) straight leg raising failed to produce pain; (d) manipulation failed to produce a reasonable reduction of the fracture. At operation the sciatic nerve with some soft tissue was found interposed between the fragments. After release of soft tissue the femur was plated. This resulted in the expected increased length of leg and almost complete recovery from the sciatic palsy at the end of 1 year. NEER, C., GRANTHAM,S. A., FOSTER, X. X., and, AUFRANC,O. E. (1971), ' Femoral Shaft Fracture with Sciatic Nerve Palsy ', J. Am. med. Ass., 214, 2307. Femoral Head Viability A method of measuring tissue blood-flow by study of hydrogen diffusion has been adapted to estimate the vascularity of the femoral head after fracture of the neck. The method appears capable of yielding the information sought, but the results have not yet been correlated with subsequent clinical and radiological evidence of changes in the femoral head. AtmE, S., LIE, M., and RAEDER, M. (1969), ' T h e Early Assessment of Femoral Head Viability in Cases of Fracture of the Femoral Neck ', Acta chit. scand., 135, 205.
DANDY" FAT EMBOLISM AFTER FEMORAL HEAD REPLACEMENT
85
FAT E M B O L I S M FOLLOWING PROSTHETIC REPLACEMENT OF THE FEMORAL HEAD D. J. D A N D Y
Watford General Hospital
Four patients are described in whom cardiac arrest occurred between 2 and 5 minutes after placing acrylic cement in the femoral shaft during the insertion of a Thompson hip prosthesis for subcapital fracture of the neck of the femur. Two of the patients died, in both of whom post-mortem examination showed petechial haemorrrhages on the visceral pleurae and histological examination showed massive pulmonary fat embolism with fat globules in the capillaries. The other two patients were successfully resuscitated and developed a pyrexia after operation which lasted 4 days; their chest radiographs showed bilateral diffuse mottling consistent with pulmonary fat embolism. A possible cause for the fat embolism is suggested. INTRODUCTION IN one year at the Watford General Hospital, 22 Thompson hip prostheses were inserted for subcapital fracture of the neck of the femur; 4 patients suffered cardiac arrest during the operation. The average age of the 4 patients suffering cardiac arrest was 79.5 years, compared with an average age of 76.6 years in the whole group. During the same year 32 total hip replacements were inserted for osteo-arthritis. No patient in this group, the average age of which was 63.75 years, suffered cardiac arrest. Five patients suffering cardiac arrest after the insertion of acrylic bone cement into the femoral shaft have recently been reported (Burgess, 1970; Hyland and Robbins, 1970; Powell, McGrath, Lahiri, and Hill, 1970; Gresham, Kuczyfiski, and Rosborough, 1971), in three of whom (Burgess, 1970; Hyland and Robbins, 1970; Gresham and others, 1971) pulmonary fat embolism was demonstrated on histological examination of post-mortem material. All occurred after the insertion of Thompson hip prostheses for subcapital fracture of the femoral neck, and none followed total hip replacement.
through a posterior incision, using C.M.W. cement* containing barium sulphate, which was used in all the patients. She was considered unfit for operation on both hips at once. A Steinmann's pin was therefore passed through the left tibia and axial traction applied to the limb. She made an uninterrupted recovery from this operation. However, 5 weeks later it was apparent that bony union was not occurring in the left femur. A Thompson prosthesis was inserted through an anterolateral approach to the left hip. Premedication of Valium (diazepam) 5 nag. and atropine 0.6 nag. was given 45 minutes before operation and anaesthesia induced with methohexitone 90 rag. The patient was intubated after injecting Scoline (suxamethonium chloride) 50 rag. The patient's condition was satisfactory until approximately 5 minutes after placing acrylic cement in the femoral shaft, when the patient's bloodpressure became unrecordable and spontaneous respiration ceased. External cardiac massage and ventilation with pure oxygen was commenced. After 30 min. E.C.G. showed no ventricular complexes and resuscitation was discontinued. Routine post-mortem examinationshowed petechial haemorrhages over the visceral pleurae and histological examination of frozen sections of lung stained with scharlach R showed massive pulmonary fat emboli with fat globules in the pulmonary capillaries. Frozen sections of brain stained with scharlach R were examined microscopically, but no fat emboli were found. No petechiae were visible on macroscopic examination of the skin.
CASE REPORTS Case 1 An 87-year-old woman sustained bilateral femoral neck fractures in an epileptic fit. Two days after admission to hospital she received a transfusion of packed red blood-cells and 8 days after admission a Thompson prosthesis was fixed into the right femur,
Case 2 An 80-year-old woman fell at home, sustaining a subcapital fracture of the right femoral neck. She was * C.M.W. Bone Cement, C.M.W. Laboratories Ltd., Preston New Road, Blackpool.
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obese and suffered from diabetes mellitus, which was controlled by a low carbohydrate diet. Before the accident she could just manage to climb a flight of stairs but was prevented from doing more by dyspnoea. She was not receiving treatment for this condition. Clinical examination did not reveal evidence of congestive cardiac failure. Having decided to treat the fracture conservatively, Hamilton Russell traction was applied to the right lower limb. The patient could not tolerate this form of treatment and it was decided to insert a Thompson hip prosthesis 2 days after admission to hospital. Premedication of Valium (diazepam) 10mg. and atropine 0"6 mg. was given. Anaesthesia was induced with thiopentone and maintained with halothane; Scoline (suxamethonium chloride) was given to permit endotracheal intubation. Her condition was satisfactory for the first 30 min. after induction of anaesthesia when, 2 minutes after insertion of the cement, the anaesthetist noticed tachypnoea for approximately 30 sec. before a precipitous drop in bloodpressure occurred. The pulse and blood-pressure became recordable after administering pure oxygen and lowering the head of the operating table. The operation was then concluded uneventfully. The patient was anaesthetized for a total of 65 minutes when the patient's pulse became irregular and ventricular fibrillation supervened. Defibrillation produced asystole, but fibrillation recurred. Further defibrillation restored a normal complex for a short period but the pulse became more irregular and could not be restored to normal. Attempts at resuscitation were abandoned 45 min. after dosing the wound. At post-mortem there were petechial haemorrhages on the visceral pleurae of both lungs, and microscopic examination of frozen sections of lung stained with scharlach R showed evidence of massive pulmonary fat embolism with fat globules in the pulmonary capillaries. There was also an ante-mortem thrombus lodged in the artery supplying the upper lobe of the left lung. A few fat globules were demonstrated histologically in the glomeruli of both kidneys. Case 3 A n 80-year-old woman fell in her garden and sustained a subcapital fracture of the right femoral neck. For many years she had suffered from dyspnoea and occasional anginal pain on exertion. She had been receiving digoxin 0.25 mg. b.d. and Lasix (frusemide) 40 mg. on alternate days before admission and this was continued in hospital. On examination there were no signs of congestive cardiac failure although she was found to have atrial fibrillation. Two days after admission to hospital a Thompson prosthesis was inserted into the right femoral shaft. A premedieation of atropine 0"6 rag. was given thirty minutes before operation and anaesthesia was induced with thiopentone and maintained with halothane. Scoline (suxamethonium chloride) was injected before intubation and relaxation maintained with curare. A Thompson prosthesis was inserted 45 min. after induction of anaesthesia, using an anterolateral approach to the hip. One minute after inserting the prosthesis and 3 min. after starting to insert the acrylic cement the pulse and blood-pressure became unrecordable but returned after a further 2 rain.; after 5 min. the systolic blood-pressure was 100 ram. Hg. The patient's lungs were ventilated with pure oxygen and the head of the operating table lowered as soon as the cardiac arrest occurred. The
Injury
Oct. 1971
operation was concluded uneventfully with a total anaesthetic time of 1 hr. 10 min. The patient made a slow but steady recovery and was discharged home 5 weeks after operation. She had a pyrexia of 99 ° F. for 4 days after operation and a chest radiograph 17 days after operation showed diffuse mottling of both lung fields. The lungs had a normal radiological appearance on the day before operation. These radiological changes were consistent with a diagnosis of fat embolism or of bronchopneumonia. The radiological appearance of the lung fields had returned to normal 30 days after operation. Case 4 A 71-year-old man fell off his chair, sustaining a subcapital fracture of the left femoral neck. Before the accident he was unable to walk more than about 100 yards because of dyspnoea, and suffered occasional orthopnoea at night. He had received no treatment for his condition before the accident but was given digoxin 0.25 mg. b.d., Lasix (frusemide) 40mg. daily, and aminophylline suppositories at night before operation. There was no evidence of congestive cardiac failure on admission to hospital and 2 days later a Thompson prosthesis was inserted in the left femur. Premedication of Valium (diazepam) 10rag. and atropine 0.6 rag. was given. Anaesthesia was induced with methohexitone and maintained with halothane. Scoline (suxathoniurn chloride) 50 mg. was given to permit endotracheal intubation. The procedure was uneventful until 45 rain. after induction of the anaesthetic, which corresponded to 3 min. after the acrylic was placed in the shaft of the femur, when the pulse and blood-pressure became uurecordable and spontaneous respiration ceased. The patient was tilted head down, pure oxygen administered, and 100 ml. of 8-4 per cent sodium bicarbonate given intravenously. The pulse and blood-pressure could be recorded after 2 minutes and the patient made a steady recovery. After operation he had a pyrexia of 100-101 ° F. for 4 days and a chest radiograph showed patchy consolidation throughout both lung fields, which had resolved 4 weeks after operation. The radiographic changes were consistent with fat embolism or bronchopneumonia. At no time were petechiae observed on the skin. He made a slow recovery from operation.
DISCUSSION This p a p e r r e p o r t s a series o f 22 consecutive o p e r a t i o n s for subcapital f r a c t u r e of the femoral neck in w h i c h a T h o m p s o n prosthesis was fixed into the f e m u r with acrylic cement. In 4 o f these patients cardiac arrest occurred d u r i n g the o p e r a t i o n ; 2 p a t i e n t s could n o t be resuscitated a n d massive p u l m o n a r y fat e m b o l i s m was f o u n d at p o s t - m o r t e m e x a m i n a t i o n . T w o surviving patients h a d a pyrexia after operation, with changes o n the chest r a d i o g r a p h consistent with b r o n c h o p n e u m o n i a , b u t it is possible t h a t t h e radiological changes were due to fat embolism. Petechiae were n o t seen o n the skin o f a n y patient. N o cardiac arrest occurred d u r i n g 32 consecutive total hip r e p l a c e m e n t operations f~r
Volume 3 Number 2
D A N D Y " FAT EMBOLISM AFTER FEMORAL HEAD REPLACEMENT
degenerative joint disease performed during the same period. Gresham and others (1971) have reported that of 32 patients with femoral neck fractures treated by Thompson replacement arthroplasty using acrylic cement, 1 died immediately the prosthesis was inserted; in this patient and in 4 others who died within 36 hours of the same procedure, massive pulmonary fat embolism was demonstrated at post-mortem. Danckwardt-Lilliestrom, Lorenzi, and Olerud (1970) have shown that after reaming the tibial shaft of rabbits, fat globules are found in increased numbers in the vessels of the Haversian canals and under the periosteum; they found this to be caused by a rise in intramedullary pressure during reaming. While reaming of the femoral shaft alone may give rise to pulmonary fat emboli, it is possible that the forced insertion of acrylic cement temporarily increases the number of fat globules entering the circulation and arriving in the lung. Cardiac arrest occurred in all 4 patients reported here within 5 min. of insertion of the acrylic cement. It is not universally agreed that fat in the pulmonary capillaries is itself of clinical significance. Emson (1958) found fat in the pulmonary capillaries of 89 per cent of patients undergoing post-mortem examination after death from trauma. Other writers (Vance, 1931; Warren, 1946; Scully, 1956; Sevitt, 1966) have made similar reports, and many (Armin and Grant, 1951; Grant and Reeve, 1951; Scully, 1956) believe that pulmonary fat emboli are usually harmless. Pulmonary and cerebral fat embolism are reported in patients who died after external cardiac massage without other history of trauma (Jackson and Greendyke, 1965). The presence of massive pulmonary fat embolism at post-mortem examination with no other abnormality is not proof that fat embolism was the sole cause of death. Several causes have been suggested for cardiac arrest following the use of acrylic cement, including absorption of the monomer, air or fat embolism (Burgess, 1970; Harris, 1970; Hyland and Robbins, 1970; Gresham and others, 1971), and heat generated by the acrylic as it polymerizes (Durbin, Jeffery, Blundell Jones, Ling, Scott, Woodyard, and Wrighton, 1970). The approach to the hip, the position of the patient during operation, and the depth of anaesthesia could also be important. There may be interaction between one of the constituents of the acrylic cement and drugs given before operation to improve the patient's cardiac state, or with drugs given during operation. Few reports give
87
sufficient technical or clinical detail to permit further investigation. The femoral shafts of the patients reported here were not ' vented ', either by placing a cannula clown the femoral shaft or by drilling a small hole in the femoral cortex before insertion of the acrylic. Care was taken that acrylic was not inserted until it was as firm as could conveniently be handled, or before all odour of monomer had dispersed. It is noticeable that neither in this study nor in the recent reports (Burgess, 1970, Durbin and others, 1970; Frost, 1970; Harris, 1970; Hyland and Robbins, 1970; Powell and others, 1970; Gresham and others, 1971) has cardiac arrest been reported in patients undergoing total hip replacement for degenerative joint disease. There are several possible explanations for this apparent difference between the frequency of cardiac arrest after prosthetic replacement of the upper femur for fracture, and after replacement for degenerative joint disease. It may be that pulmonary fat emboli caused by fracture of the femoral neck render the lungs in some way more sensitive to further fat embolism occurring at the time of operation, to monomer or any other constituent of acrylic cement, or to some vaso-active substance released from bone or marrow by the heat of polymerization. Other differences exist between patients undergoing Thompson replacement arthroplasty and total hip replacement. Total hip replacement tends to be performed on patients who are both younger and fitter than those who sustain a subcapital fracture of the femoral neck. The average age of the 32 patients in this series who underwent total hip replacement was 63.75 years and the average age of those patients suffering cardiac arrest was 79-5 years. The latter patients would probably have been considered unfit for total hip replacement, had it been indicated clinically, because of their poor cardiorespiratory reserve. It is possible that the femoral neck adjacent to an osteo-arthritic hip differs from a fractured femoral neck in some way which renders pulmonary fat embolism less likely to occur after the insertion of acrylic. There is evidence (Phillips, 1966) that the pattern of venous drainage of the upper end of the femur in osteo-arthritis is different from that observed in patients who have sustained a fracture of the femoral neck. It is common experience that the femoral neck below an osteo-arthritic hip is harder and thicker than a femoral neck which has sustained a subcapital fracture; and that a fracture next to an osteoarthritic hip is a rarity.
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INJURY" THE BRITISH JOURNAL OF ACCIDENT SURGERY
A prospective study is needed to examine the venous blood for fat embolism in patients undergoing prosthetic replacement at the hip. Acknowledgements Thanks are due to Mr. A. Benjamin and Mr. K. I. Nissen for allowing me to study their patients, and to Professor R. G. Burwell for his helpful criticism during the preparation of this paper. REFERENCES ARMIN, J., and GRANT, R. T. (1951), 'Observations on Gross Pulmonary Fat Embolism in Man and the Rabbit ', Clin. Sci., 10, 442. BURGESS,D. M. (1970), Letter, Br. reed. J., 3, 588. DANCKWARDT-LILLIESTROM,G., LORENZI, G. L., and OLERtrO, S. (1970), 'Intramedullary Nailing after Reaming ', Acta orthop, scand., 134. DURBIN, F. C., JEFFERY, C. C., BLUNDELLJONES, G., LING, R. S. M., SCOTT, P. J., WOODYARD,J. E., and WRIGHTON, J. E. (1970), Letter, Br. reed. J., 4, 176. EMSON, H. E. (1958), ' Fat Embolism studied in 100 Patients dying after Injury ', J. clin. Path., 11, 28. FROST, P. M. (1970), Letter, Br. reed. J., 3, 524.
Injury Oct. 1971
GRANT, R. T., and REEVE,E. B. (1951), ' Observations on the General Effects of Injury in Man ', Spec. Rep. Ser. reed. Res. Court., No. 277. GRESHAM, G. A., KUCZYI~ISKI,A., and ROSBOROUGH, D. (1971), ' Fatal Fat Embolism following Replacement Arthroplasty for Transcervical Fractures of the Femur ', Br. reed. J., 2, 617. HARRIS, N. H. (1970), Letter, Ibid., 3, 523. HYLAND, J., and ROBmNS, R. H. C. (1970), Letter, Ibid., 4, 176. JACKSON, C. T., and GREENDYKE, R. i . (1965), 'Pulmonary and Cerebral Fat Embolism after Closed Chest Cardiac Massage ', Surgery Gynec. Obstet., 120, 25. PHILLIPS, R. S. (1966), 'Phlebography in Osteoarthritis of the Hip ', J. Bone Jt Surg., 48B, 280. POWELL, J. N., MCGRATH, P. J., LAHIRI, S. K., and HILL, P. (1970), 'Cardiac Arrest associated with Bone Cement ', Br. reed. J., 3, 326. SCULLY, R. E. (1956), ' F a t Embolism in Korean Battle Casualties ', Am. J. Path., 32, 379. SEVtTT, S. (1966), ' T h e Boundaries Between Physiology, Pathology and Irreversibility after Injury ', Lancet, 2, 1203. VANCE, B. M. (1931), ' T h e Significance of Fat Embolism ', Archs Surg., Chicago, 23, 426. WARREN, S. (1946), ' Fat Embolism ', Am. J. Path., 22, 69.
Requestsfor reprints should be addressed to:--D. 2. Dandy, Esq., F.R.C.S., Orthopaedic Department, St. Bartholomew's Hospital, West Smithfield,London E.C.I.
ABSTRACTS
FRACTURES AND DISLOCATIONS Fracture-dislocation of the Shoulder with Intrathoracic Displacement of the Head of the Humerus Stableforth, Ayres, and Taylor record this rare complication (3 previous cases reported in the literature) of fracture-dislocation of the shoulder with penetration of the chest wall by the head of the humerus with haemopneumothorax. Hypotension was corrected by intravenous infusion and an underwater seal drainage was set up. Recurrence of hypotensionwhile stereo-radiographs were being taken failed to respond to transfusion. Therefore, thoracotomy was performed. The head of the humerus was removed and a massive haemothorax was found, probably from torn intercostal vessels. There was a laceration of lung tissue. The intercostal vessels to the second, third, fourth, and fifth intercostal spaces were ligated, the lung tear was sutured, and chest drains inserted. The patient recovered but did not develop active shoulder function. STABLEFORTH,P. G., AYRES, P., and TAYLOR,G. A. (1971), ' Fracture Dislocation of the Upper Humerus into the Thoracic Cavity ', Can. J. Surg., 14, 235. Fractured Femur with Sciatic Palsy Drs. Neer, Grantham, and Foster from New York and Dr. Aufranc from Boston discuss the problem of a 4-year-old boy with fractures of both femoral shafts,
one being complicated by a sciatic palsy. There were several important points in the discussion worthy of attention. All the speakers agreed that early operative exploration was to be avoided and plate fixation at this early age was contra-indicated. This example proved to be the exception, and operation was performed early because (a) the ecchymosis and ease of palpation of the end of one of the fragments indicated that the deep fascia had been perforated; (b) manipulation under anaesthesia failed to demonstrate crepitus; (c) straight leg raising failed to produce pain; (d) manipulation failed to produce a reasonable reduction of the fracture. At operation the sciatic nerve with some soft tissue was found interposed between the fragments. After release of soft tissue the femur was plated. This resulted in the expected increased length of leg and almost complete recovery from the sciatic palsy at the end of 1 year. NEER, C., GRANTHAM,S. A., FOSTER, X. X., and, AUFRANC,O. E. (1971), ' Femoral Shaft Fracture with Sciatic Nerve Palsy ', J. Am. med. Ass., 214, 2307. Femoral Head Viability A method of measuring tissue blood-flow by study of hydrogen diffusion has been adapted to estimate the vascularity of the femoral head after fracture of the neck. The method appears capable of yielding the information sought, but the results have not yet been correlated with subsequent clinical and radiological evidence of changes in the femoral head. AtmE, S., LIE, M., and RAEDER, M. (1969), ' T h e Early Assessment of Femoral Head Viability in Cases of Fracture of the Femoral Neck ', Acta chit. scand., 135, 205.