- Email: [email protected]
Failure of PFNA: Helical blade perforation and tip-apex distance
Letters to the Editor / Injury, Int. J. Care Injured 43 (2012) 1219–1233
1227
were reported in several case reports. After review of the PFNA literature in English, we found a total of 12 cases helical blade protrusion in 6 papers (Table 1).1–6 From the provided data and radiographs, we can summarise that most patients were old women, the fracture reduction and caput-collum-diaphyseal angle were acceptable, and most patients took full weight bearing immediately after operation. Four perforations occurred after a fall on the affected hip, one with subclinical low-grade infection, one with helical blade tail abutting the lateral cortex, and six had none aetiology. Most perforations occurred within 6 weeks. Furthermore, blade tip-apex distance (TAD) in four available patients was less than 20 mm or even 15 mm. Contrast to femoral head lag screws (blunt head, wrench-in, large axial contact area and move cancellous bone), the helical blade has its own unique characteristics in insertion mode and morphological design (relative sharp head, hammer-in, large circumference contact area and compact cancellous bone). These features make the helical blade more likely to move axially (medial perforation) than vertically (superior cutout) under loading (weight bearing). Biomechanical studies proved that the helical blade system showed a significantly increased stability of fracture fixation.7,8 For example, Strauss et al.8 performed a biomechanical test in 6 paired cadaver femurs. They found that inferior femoral head displacement was significantly less in helical blade group compared with lag screw group after each cyclic loading with 750 N applied for 10, 100, 1000 and 10,000 cycles. Born and coworkers further demonstrated that under cyclic loading, the hip screws migrated predominantly in a cephalad direction, and in contrast, the helical blades exhibited a distinct migration in their axial direction.9 From 2006 to 2010, our hospital performed more than 500 cases of PFNA and PFNA-II for geriatric pertrochanteric and intertrochanteric hip fractures. No cutout or medial perforation was encountered. Besides the beginning time of weight bearing was relatively late, usually 1 month after operation, we think, our good results were mainly attributed to two technical factors. The first is TAD. In our opinion, TAD between 20 mm and 25 mm is optimal for helical blade. We never insert the helical blade much deeper. Thus, a shorter blade should be chosen, rather than recommended in the manufacturer’s operative guidelines. The second is no pre-reaming of the head-neck fragment, only a lateral cortical entry hole is drilled. This avoids cancellous bone removing from the route which the helical blade will pass under hammer impaction.
and if this happens we recommend that the unopened cavity be entered as quickly as possible. Conflict of interest statement To the best of my knowledge neither myself, nor any of the other authors have any vested interests that may inappropriately influence this work. Reference 1. Clarke Damian L, Gall. Tamara MH, Thomson. Sandie R. Double jeopardy revisited: Clinical decision making in unstable patients with, thoraco-abdominal stab wounds and, potential injuries in multiple body cavities. Injury 2011;42(May (5)):478–81.
Nishant Bedi* Daniel Frith Michael Walsh The Royal London Trauma Service, The Royal London Hospital, Whitechapel Road, London, E11BB, United Kingdom *Corresponding author. Tel.: +44 07940577549 E-mail address: [email protected] (N. Bedi). doi:10.1016/j.injury.2011.08.006
Letter to the Editor Failure of PFNA: Helical blade perforation and tip-apex distance
To the editor, Since the clinical introduction of proximal femoral nail antirotation (PFNA) by AO group in 2004 and PFNA-II (Asian version) in 2008, this type of cephalomedullary nail with single head-neck helical blade were commonly used in unstable pertrochanteric and intertrochanteric fractures in geriatric patients. Recently, severe complications of helical blade perforation through the femoral head, into the hip joint or even the pelvis,
Table 1 Summary of 12 cases in literatures with helical blade perforation in PFNA. Authors
Year
Journal
No. patients
Sex/age
AO/OTA code
Fracture reduction GA angle
CCD angle
Blade TAD (mm)
Time of weight bearing
Perforation time after PFNA
Aetiology
Revision surgery
Simmermacher
2008
Injury
4/313
NA
A2, A3
NA
NA
NA
3 within 6m
Brunner
2008
JOT
3
F/89
A2
AP 153 Lt 180
129
14.6
Most immediate fully Immediate fully
6w
F/88
A2
AP 162 Lt 180
131
19.32
Immediate fully
6w
3 fall on affected hip Fall on affected hip None
F/69
A2
AP 155 Lt NA
140
NA
Immediate fully
6w
Yes, no detail Shorter blade Shorter blade THR
NA
4w 6w
1 month with cane Immediate fully Immediate fully
2m
Mereddy
2009
Injury
2/62
NA
A2, A3
Poor
NA
Cheung
2011
JOT
1
M/81
A2.2
AP 166 Lt 178
128
AS placement of blade 16
Takigami Frank
2011 2011
JOT JOT
1 1
F/79 F/87
A2 A2
NA NA
NA
15.8 NA
3m 3w
Subclinical low-grade infection None Blade abutting cortex None None
THR THR THR THR
GA angle, Garden-Alignment angle; AP, anteroposteral; Lt, lateral; AS, anterosuperior; CCD angle, caput-collum-diaphyseal angle; THR, total hip replacement; NA, not available.
Letters to the Editor / Injury, Int. J. Care Injured 43 (2012) 1219–1233
1228
In conclusion, we believe that the helical blades should be placed centrally in the femoral head in both AP and lateral views, but not so deeply as recommended for lag screws. Blade TAD between 20 mm and 25 mm is excellent, and this may play a great role in avoiding its medial migration and perforation postoperatively. Conflict of interest statement The authors report no financial disclosures related to this manuscript. References 1. Simmermacher RK, Ljungqvist J, Bail H, Hockertz T, Vochteloo AJH, Ochs U, et al. The new proximal femoral nail antirotation (PFNA) in daily practice: results of a multicentre clinical study. Injury 2008;39:932–9. 2. Brunner A, Jockel JA, Babst R. The PFNA proximal femur nail in treatment of unstable proximal femur fractures––3 cases of postoperative perforation of the helical blade into the hip joint. J Orthop Trauma 2008;22:731–6. 3. Mereddy P, Kamath S, Ramakrishnan M, Malik H, Donnachie N. The AO/ASIF proximal femoral nail antirotation (PFNA): a new design for the treatment of unstable proximal femoral fractures. Injury 2009;40:428–32. 4. Cheung JPY, Chan CF. Cutout of proximal femoral nail antirotation resulting from blocking of the gliding mechanism during fracture collapse. J Orthop Trauma 2011;25:e51–5. 5. Takigami I, Ohnishi K, Ito Y, Nagano A, Sumida H, Tanaka K, et al. Acetabular perforation after medial migration of the helical blade through the femoral head after treatment of an unstable trochanteric fracture with proximal femoral nail antirotation (PFNA): a case report. J Orthop Trauma 2011;25:e86–9. 6. Frank MA, Yoon RS, Yalamanchili P, Choung EW, Liporace FA. Forward progression of the helical blade into the pelvis after repair with the trochanter fixation nail (TFN). J Orthop Trauma 2011;25(10):e100–3. 7. Sommers MB, Roth C, Hall H, Kam BCC, Ehmke LW, Krieg JC, et al. A laboratory model to evaluate cutout resistance of implants for pertrochanteric fracture fixation. J Orthop Trauma 2004;18:361–8. 8. Strauss E, Frank J, Lee J, Kummer FJ, Tejwani N. Helical blade versus sliding hip screw for treatment of unstable intertrochanteric hip fractures: a biomechanical evaluation. Injury 2006;37:984–9. 9. Born CT, Karich B, Bauer C, von Oldenburg G, Augat P. Hip screw migration testing: first results for hip screws and helical blades utilizing a new oscillating test method. J Orthop Res 2011;29(5):760–6.
Jia-Qian Zhou Shi-Min Chang* Department of Orthopedic Surgery, Tongji Hospital, Tongji University, 389 Xincun Road, Shanghai 200065, PR China *Corresponding author. Tel.: +86 21 66111092 E-mail address: [email protected] (S.-M. Chang)
doi:10.1016/j.injury.2011.10.024
Letter to the Editor Chaharshanbe Soori and Nowruz (Iranian’s ceremony): Fireworks and injury caused by it Fireworks are used in many celebrations around the world, the Fourth of July (the United States, Independence Day), the New Year in China, Halloween and Guy Fawkes night in the UK, Diwali in India, Hari Roya Festival in Malaysia and Prophet Mohammad’s Birthday in Libya. People of Persia celebrate the last Wednesday of the year on its eve, the Tuesday night. According to the Persian calendar, it is named Chaharshanbe Soori, which literally means ‘red Wednesday’. The event precedes Nowrouz (the Persian New year) and comprises several traditions of which setting up bonfires and jumping over them is an integral part. The origin of festivity goes back to a Zoroastrian tradition circa 1725 BC.1
In today’s Iran, the original ceremony of bonfires has been transformed into a social bedlam in the big cities in which a wide variety of illegal and hand-made firework agents are being used.1 Many studies have been done on the injuries caused by fireworks all over the world. In one research done in the United States (1990–2003), an estimated 85 500 firework-related injuries of only children were treated in the US emergency departments during the 14-year study period. Injured children had a mean age of 10.8 years, and 77.9% were male. Fireworks users accounted for 49.5% of the injuries, whereas 22.2% of the injuries were to bystanders; however, user status could not be determined in 28.3% of cases.2 A prospective study involving all casualty departments in Trent Region and 81% of the major eye units in UK was performed to determine ocular morbidity from the use of fireworks during 1986. A serious injury was defined as involving admission to hospital and/or intraocular damage of all the injuries from fireworks; 16.7% seen at major eye units were serious and were caused by rockets or exploding fireworks. Only 53% of all injuries and 12.5% of serious injuries involved children, and in contrast to the 1950s and early 1960s, young adults appear at greatest risk in the 1980s.3 In other research in China, they observed 25 eyes in 24 patients. Injuries were more frequent in children (10, 41/7%), males (19, 79.2%) and as open globe injury (15, 62.5%). The most common pyrotechnical products causing accidents were firecrackers (12, 50%). Rural residents had significantly higher rate of injury compared to urban residents.4 In an Iranian study about the issue, hands were the most common place of injury (up to 53%) followed by eyes (up to 27%) which also has sustained the most serious ones. An even appalling aspect is that injuries affect bystanders or passersby too.1 Another study done during the firework season in the UK shows that most of the patients presented to emergency department were 10–20 years old. Hands and feet were the organs most affected.5 In our cross-sectional study done in the Chaharshanbe Soori of 1389 and the Nowruz of 1390, the mean age of the people injured was 21.6 6.6 (mode = 14). Amongst 29 patients, 82.8% were male and the rest were female. According to the occupation, there were 11 students and seven self-employed persons amongst them (24.1%). There were three policemen and three housewives (10.3%). Twenty cases were injured whilst using the firecrackers. The number of people who were injured during preparing the rockets (three persons) was equal to the injured bystanders. The most common place for the event was home (48.3%) followed by public places (27.6%). Most of injured people were urban residents (96.6%) and most of them had superficial damages (72.4%). About 22 persons had been taken to the hospital by family members (75.9%) and the others by EMS and passersby. Hands were the most affected organ of injury, and then eyes were injured too much and caused noticeable problems for the person. It is suggested that traditional ceremonies should be revived, but before that culturalisation of the society should be done.
References 1. Mohamadi Sf, Mohammadi Sm, Ashrafi E, Hatef E, Rahbari H. Chaharshanbesoori fireworks and public health. Iran J Ophthalmol 2011;23. 2. Rachel J, Witsman R, Comstock D, Smith GA. Pediatric firework-related injuries in United States: 1990–2003. Pediatrics 2006;118:296–303. 3. Vernon SA. Fire works and the eye. J R Soc Med 1988;81:569–71. 4. Yuan J, Xing Y-q, Yang Y-n, Ai M, Yang A-h, Zhou L-h. Clinical analysis of fireworkrelated ocular injuries during spring festival 2009. Graefes Arch Clin Exp Ophtalmol 2010;248:333–8.
1227
were reported in several case reports. After review of the PFNA literature in English, we found a total of 12 cases helical blade protrusion in 6 papers (Table 1).1–6 From the provided data and radiographs, we can summarise that most patients were old women, the fracture reduction and caput-collum-diaphyseal angle were acceptable, and most patients took full weight bearing immediately after operation. Four perforations occurred after a fall on the affected hip, one with subclinical low-grade infection, one with helical blade tail abutting the lateral cortex, and six had none aetiology. Most perforations occurred within 6 weeks. Furthermore, blade tip-apex distance (TAD) in four available patients was less than 20 mm or even 15 mm. Contrast to femoral head lag screws (blunt head, wrench-in, large axial contact area and move cancellous bone), the helical blade has its own unique characteristics in insertion mode and morphological design (relative sharp head, hammer-in, large circumference contact area and compact cancellous bone). These features make the helical blade more likely to move axially (medial perforation) than vertically (superior cutout) under loading (weight bearing). Biomechanical studies proved that the helical blade system showed a significantly increased stability of fracture fixation.7,8 For example, Strauss et al.8 performed a biomechanical test in 6 paired cadaver femurs. They found that inferior femoral head displacement was significantly less in helical blade group compared with lag screw group after each cyclic loading with 750 N applied for 10, 100, 1000 and 10,000 cycles. Born and coworkers further demonstrated that under cyclic loading, the hip screws migrated predominantly in a cephalad direction, and in contrast, the helical blades exhibited a distinct migration in their axial direction.9 From 2006 to 2010, our hospital performed more than 500 cases of PFNA and PFNA-II for geriatric pertrochanteric and intertrochanteric hip fractures. No cutout or medial perforation was encountered. Besides the beginning time of weight bearing was relatively late, usually 1 month after operation, we think, our good results were mainly attributed to two technical factors. The first is TAD. In our opinion, TAD between 20 mm and 25 mm is optimal for helical blade. We never insert the helical blade much deeper. Thus, a shorter blade should be chosen, rather than recommended in the manufacturer’s operative guidelines. The second is no pre-reaming of the head-neck fragment, only a lateral cortical entry hole is drilled. This avoids cancellous bone removing from the route which the helical blade will pass under hammer impaction.
and if this happens we recommend that the unopened cavity be entered as quickly as possible. Conflict of interest statement To the best of my knowledge neither myself, nor any of the other authors have any vested interests that may inappropriately influence this work. Reference 1. Clarke Damian L, Gall. Tamara MH, Thomson. Sandie R. Double jeopardy revisited: Clinical decision making in unstable patients with, thoraco-abdominal stab wounds and, potential injuries in multiple body cavities. Injury 2011;42(May (5)):478–81.
Nishant Bedi* Daniel Frith Michael Walsh The Royal London Trauma Service, The Royal London Hospital, Whitechapel Road, London, E11BB, United Kingdom *Corresponding author. Tel.: +44 07940577549 E-mail address: [email protected] (N. Bedi). doi:10.1016/j.injury.2011.08.006
Letter to the Editor Failure of PFNA: Helical blade perforation and tip-apex distance
To the editor, Since the clinical introduction of proximal femoral nail antirotation (PFNA) by AO group in 2004 and PFNA-II (Asian version) in 2008, this type of cephalomedullary nail with single head-neck helical blade were commonly used in unstable pertrochanteric and intertrochanteric fractures in geriatric patients. Recently, severe complications of helical blade perforation through the femoral head, into the hip joint or even the pelvis,
Table 1 Summary of 12 cases in literatures with helical blade perforation in PFNA. Authors
Year
Journal
No. patients
Sex/age
AO/OTA code
Fracture reduction GA angle
CCD angle
Blade TAD (mm)
Time of weight bearing
Perforation time after PFNA
Aetiology
Revision surgery
Simmermacher
2008
Injury
4/313
NA
A2, A3
NA
NA
NA
3 within 6m
Brunner
2008
JOT
3
F/89
A2
AP 153 Lt 180
129
14.6
Most immediate fully Immediate fully
6w
F/88
A2
AP 162 Lt 180
131
19.32
Immediate fully
6w
3 fall on affected hip Fall on affected hip None
F/69
A2
AP 155 Lt NA
140
NA
Immediate fully
6w
Yes, no detail Shorter blade Shorter blade THR
NA
4w 6w
1 month with cane Immediate fully Immediate fully
2m
Mereddy
2009
Injury
2/62
NA
A2, A3
Poor
NA
Cheung
2011
JOT
1
M/81
A2.2
AP 166 Lt 178
128
AS placement of blade 16
Takigami Frank
2011 2011
JOT JOT
1 1
F/79 F/87
A2 A2
NA NA
NA
15.8 NA
3m 3w
Subclinical low-grade infection None Blade abutting cortex None None
THR THR THR THR
GA angle, Garden-Alignment angle; AP, anteroposteral; Lt, lateral; AS, anterosuperior; CCD angle, caput-collum-diaphyseal angle; THR, total hip replacement; NA, not available.
Letters to the Editor / Injury, Int. J. Care Injured 43 (2012) 1219–1233
1228
In conclusion, we believe that the helical blades should be placed centrally in the femoral head in both AP and lateral views, but not so deeply as recommended for lag screws. Blade TAD between 20 mm and 25 mm is excellent, and this may play a great role in avoiding its medial migration and perforation postoperatively. Conflict of interest statement The authors report no financial disclosures related to this manuscript. References 1. Simmermacher RK, Ljungqvist J, Bail H, Hockertz T, Vochteloo AJH, Ochs U, et al. The new proximal femoral nail antirotation (PFNA) in daily practice: results of a multicentre clinical study. Injury 2008;39:932–9. 2. Brunner A, Jockel JA, Babst R. The PFNA proximal femur nail in treatment of unstable proximal femur fractures––3 cases of postoperative perforation of the helical blade into the hip joint. J Orthop Trauma 2008;22:731–6. 3. Mereddy P, Kamath S, Ramakrishnan M, Malik H, Donnachie N. The AO/ASIF proximal femoral nail antirotation (PFNA): a new design for the treatment of unstable proximal femoral fractures. Injury 2009;40:428–32. 4. Cheung JPY, Chan CF. Cutout of proximal femoral nail antirotation resulting from blocking of the gliding mechanism during fracture collapse. J Orthop Trauma 2011;25:e51–5. 5. Takigami I, Ohnishi K, Ito Y, Nagano A, Sumida H, Tanaka K, et al. Acetabular perforation after medial migration of the helical blade through the femoral head after treatment of an unstable trochanteric fracture with proximal femoral nail antirotation (PFNA): a case report. J Orthop Trauma 2011;25:e86–9. 6. Frank MA, Yoon RS, Yalamanchili P, Choung EW, Liporace FA. Forward progression of the helical blade into the pelvis after repair with the trochanter fixation nail (TFN). J Orthop Trauma 2011;25(10):e100–3. 7. Sommers MB, Roth C, Hall H, Kam BCC, Ehmke LW, Krieg JC, et al. A laboratory model to evaluate cutout resistance of implants for pertrochanteric fracture fixation. J Orthop Trauma 2004;18:361–8. 8. Strauss E, Frank J, Lee J, Kummer FJ, Tejwani N. Helical blade versus sliding hip screw for treatment of unstable intertrochanteric hip fractures: a biomechanical evaluation. Injury 2006;37:984–9. 9. Born CT, Karich B, Bauer C, von Oldenburg G, Augat P. Hip screw migration testing: first results for hip screws and helical blades utilizing a new oscillating test method. J Orthop Res 2011;29(5):760–6.
Jia-Qian Zhou Shi-Min Chang* Department of Orthopedic Surgery, Tongji Hospital, Tongji University, 389 Xincun Road, Shanghai 200065, PR China *Corresponding author. Tel.: +86 21 66111092 E-mail address: [email protected] (S.-M. Chang)
doi:10.1016/j.injury.2011.10.024
Letter to the Editor Chaharshanbe Soori and Nowruz (Iranian’s ceremony): Fireworks and injury caused by it Fireworks are used in many celebrations around the world, the Fourth of July (the United States, Independence Day), the New Year in China, Halloween and Guy Fawkes night in the UK, Diwali in India, Hari Roya Festival in Malaysia and Prophet Mohammad’s Birthday in Libya. People of Persia celebrate the last Wednesday of the year on its eve, the Tuesday night. According to the Persian calendar, it is named Chaharshanbe Soori, which literally means ‘red Wednesday’. The event precedes Nowrouz (the Persian New year) and comprises several traditions of which setting up bonfires and jumping over them is an integral part. The origin of festivity goes back to a Zoroastrian tradition circa 1725 BC.1
In today’s Iran, the original ceremony of bonfires has been transformed into a social bedlam in the big cities in which a wide variety of illegal and hand-made firework agents are being used.1 Many studies have been done on the injuries caused by fireworks all over the world. In one research done in the United States (1990–2003), an estimated 85 500 firework-related injuries of only children were treated in the US emergency departments during the 14-year study period. Injured children had a mean age of 10.8 years, and 77.9% were male. Fireworks users accounted for 49.5% of the injuries, whereas 22.2% of the injuries were to bystanders; however, user status could not be determined in 28.3% of cases.2 A prospective study involving all casualty departments in Trent Region and 81% of the major eye units in UK was performed to determine ocular morbidity from the use of fireworks during 1986. A serious injury was defined as involving admission to hospital and/or intraocular damage of all the injuries from fireworks; 16.7% seen at major eye units were serious and were caused by rockets or exploding fireworks. Only 53% of all injuries and 12.5% of serious injuries involved children, and in contrast to the 1950s and early 1960s, young adults appear at greatest risk in the 1980s.3 In other research in China, they observed 25 eyes in 24 patients. Injuries were more frequent in children (10, 41/7%), males (19, 79.2%) and as open globe injury (15, 62.5%). The most common pyrotechnical products causing accidents were firecrackers (12, 50%). Rural residents had significantly higher rate of injury compared to urban residents.4 In an Iranian study about the issue, hands were the most common place of injury (up to 53%) followed by eyes (up to 27%) which also has sustained the most serious ones. An even appalling aspect is that injuries affect bystanders or passersby too.1 Another study done during the firework season in the UK shows that most of the patients presented to emergency department were 10–20 years old. Hands and feet were the organs most affected.5 In our cross-sectional study done in the Chaharshanbe Soori of 1389 and the Nowruz of 1390, the mean age of the people injured was 21.6 6.6 (mode = 14). Amongst 29 patients, 82.8% were male and the rest were female. According to the occupation, there were 11 students and seven self-employed persons amongst them (24.1%). There were three policemen and three housewives (10.3%). Twenty cases were injured whilst using the firecrackers. The number of people who were injured during preparing the rockets (three persons) was equal to the injured bystanders. The most common place for the event was home (48.3%) followed by public places (27.6%). Most of injured people were urban residents (96.6%) and most of them had superficial damages (72.4%). About 22 persons had been taken to the hospital by family members (75.9%) and the others by EMS and passersby. Hands were the most affected organ of injury, and then eyes were injured too much and caused noticeable problems for the person. It is suggested that traditional ceremonies should be revived, but before that culturalisation of the society should be done.
References 1. Mohamadi Sf, Mohammadi Sm, Ashrafi E, Hatef E, Rahbari H. Chaharshanbesoori fireworks and public health. Iran J Ophthalmol 2011;23. 2. Rachel J, Witsman R, Comstock D, Smith GA. Pediatric firework-related injuries in United States: 1990–2003. Pediatrics 2006;118:296–303. 3. Vernon SA. Fire works and the eye. J R Soc Med 1988;81:569–71. 4. Yuan J, Xing Y-q, Yang Y-n, Ai M, Yang A-h, Zhou L-h. Clinical analysis of fireworkrelated ocular injuries during spring festival 2009. Graefes Arch Clin Exp Ophtalmol 2010;248:333–8.