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DHS osteosynthesis for stable pertrochanteric femur fractures with a two-hole side plate
Injury, Int. J. Care Injured (2004) 35, 999—1002
DHS osteosynthesis for stable pertrochanteric femur fractures with a two-hole side plate Michiel H.J. Verhofstada,*, Chris van der Werkenb a
Department of Surgery, St Elisabeth Hospital, P.O. Box 90151, 5000 LC Tilburg, The Netherlands Department of Surgery, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
b
Accepted 13 October 2003
KEYWORDS Pertrochanteric fracture; Hip fracture; Dynamic hip screw; Osteosynthesis; Sliding hip screw; Operative technique
Summary The sliding hip screw is the implant of choice for the operative treatment of stable pertrochanteric femur fractures (AO classification 31-A.1). For this indication, a four-hole side plate with four bicortical screws is widely used to allow full weight bearing immediately after operation, but scientific support for the need of such a long side plate is not available. A shorter side plate is potentially less invasive. Therefore, we retrospectively evaluated all 148 consecutive patients (median age 80 years) with a stable pertrochanteric femur fracture who were treated between 1995 and 2001 with a dynamic hip screw (DHS) and a short (two-hole) side plate and immediate full weight bearing mobilisation. Although two wound hematomas and four wound infections occured, 145 fractures healed radiologically without implant-related complications within 6 months. Two hip screws cut out of the femoral head due to a poor position. In one patient, the side plate broke out after a fall out of bed on the fifth postoperative day. Pull off of any two-hole side plate during early full weight bearing mobilisation without further trauma was not observed. We conclude that fixation of stable pertrochanteric femur fractures with a two-hole DHS is safe. The traditional use of a four-hole DHS plate for this indication is therefore ‘over-treatment’ since it is more invasive. ß 2003 Elsevier Ltd. All rights reserved.
Introduction The dynamic hip screw (DHS), is an ideal implant for the operative treatment of stable pertrochanteric femur fractures (AO classification 31-A.13). For this indication, a four-hole side plate with four bicortical screws is traditionally recommended to allow immediate full weight bearing. However, scientific proof for this advice is scarce. Only one clinical *Corresponding author. Tel.: þ31-13-5392922; fax: þ31-13-5363660. E-mail addresses: [email protected], [email protected] (M.H.J. Verhofstad).
study has assessed the optimal length of the side plate in stable pertrochanteric femur fractures, suggesting that a two-hole side plate provides enough stability.1 The widespread use of a four-hole side plate in stable pertrochanteric femur fractures is merely based on tradition and needs reconsideration in this era of minimally invasive surgery and evidence based medicine ‘to do the patient no further harm than necessary’. The typical patient with a hip fracture is characterised by high age, significant co-morbidity and severe osteoporosis. These factors jeopardise the surgical treatment, which is
0020–1383/$ — see front matter ß 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2003.10.030
1000
M.H.J. Verhofstad, C.v.d. Werken
Incorrect fracture classification before operation or unfamiliarity with the protocol led to operative treatment with a four-hole DHS side plate or another implant in 22 patients. These and patients suffering from a pathological fracture (n ¼ 2) were excluded from analysis. Patients suffering early postoperative death were also excluded (n ¼ 15). Endpoints in the analysis were radiological fracture consolidation, an uncomplicated postoperative follow up of at least 6 months–—if radiological proof of consolidation was unavailable–—or secondary instability of the osteosynthesis. One hundred and forty-eight patients met the inclusion criteria. Their age, gender, trauma mechanism and wound or implant-related complications (with emphasis on secondary instability) were documented.
often underestimated and performed by relatively inexperienced residents. The patient’s compliance with after-treatment is low and non-weight bearing is practically impossible. Therefore, a two-hole side plate would be better, but only if stable enough. We retrospectively evaluated the results of treatment of a stable pertrochanteric femur fracture with a two-hole plate DHS.
Patients and methods In the surgical departments of the University Medical Centre, Utrecht and the St. Elisabeth Hospital, Tilburg (both in the Netherlands) patients with hip fractures are generally operated on by surgical residents under the supervision of a senior surgeon. According to the protocol, stable two part pertrochanteric femur fractures (AO classification 31-A.1) are treated with a dynamic hip screw (DHS; Mathys Medical, Bettlach, Switzerland) with a two-hole side plate with two 4.5 mm bicortical screws. Closed reduction on a fracture table and internal fixation as described in detail in the manufacturer’s manual5 are performed under fluoroscopic control and regional or general anaesthesia, with single antibiotic prophylaxis using preoperative intravenous administration of 2 g cefazolin. Thrombosis prophylaxis was given daily during the entire hospital stay with 2500 IU dalteparine subcutaneously. Postoperatively, all patients start immediate full weight bearing under the guidance of a physiotherapist. From the central hospital registration, all patients treated for pertrochanteric femur fractures (AO classification 31-A.1) with a DHS osteosynthesis between 1995 and 2001 were identified (n ¼ 284). Their hospital charts and radiographs were examined by one author. Only patients treated for a true 31-A.1 fracture were included (n ¼ 187).
Results Fig. 1 illustrates the distribution of age. The median age was 80.0 years (range 22—96) with 85% of patients over 65 years old. One hundred patients were female and 48 male. Three patients sustained a high-energy motorcycle accident and three patients fell during a bicycle race. The remaining 142 fractures were due to a simple fall, generally at home. One hundred and thirty-nine patients (94%) with a stable pertrochanteric femur fracture, treated with a DHS using a two-hole side plate fixed with two bicortical screws and immediate weight bearing afterwards, healed uneventfully. Two patients (1.4%) developed a wound haematoma, one required re-exploration. Four (2.7%) wound infections were found, one patient was treated with antibiotics, in three cases the wound was opened, resulting in good secondary healing in two patients and a fistula in one, which healed after implant
70
Number of patients
60 50 40 30 20 10 0 0-10
11-20
21-30
31-40
41-50
51-60
61-70
Decade
Figure 1 Distribution of age.
71-80
81-90 91-100
Pertrochanteric fractures and a two-hole DHS side plate
removal. None of the infections impaired fracture healing. Three implant-related complications were seen: cut out of the sliding screw due to poor placement was seen twice (1.4%), both patients were treated by prosthetic hip replacement. One two-hole DHS plate broke out (0.7%) in a 74-year old female who fell out of her hospital bed 5 days postoperatively. Spontaneous instability of the short, two-hole side plate was never observed in any of the remaining 145 patients (success rate: 100%).
Discussion In contrast to the widespread use of a DHS with a four-hole side plate for stable pertrochanteric femur fractures, we describe our excellent results in a series of patients with such fracture treated with a two-hole side plate. An identical surgical procedure for the sliding screw itself followed by the application of a shorter side plate has potential advantages. The surgeon requires less wound exposure and operative proceedings, blood loss and operation time can be reduced. Usage of a short side plate instead of a long one can only simplify and not hamper the operative technique. These benefits can be specifically important for the typical patient with a hip fracture: high age, osteoporotic bone and significant co-morbidity, resulting in a fragile equilibrium in physical and physiological performance, traditionally with a high peri-operative mortality. Unfortunately, these patients are frequently operated under suboptimal circumstances in a (semi-) acute setting by relatively inexperienced surgeons or residents. Therefore, a quick and minimally invasive surgical procedure is preferred, but only if the osteosynthesis itself is safe. Although numerous publications have been directed toward the optimal design, position and angle of the sliding screw, only five studies on the optimal length of the side plate exist.1,2,4,6,7 Of these few studies only two deal with stable pertrochanteric femur fractures.1,6 In the only available clinical study, Bolhofner1 reported excellent results in a series of 37 consecutive patients with a stable pertrochanteric fracture, treated with a two-hole DHS and immediate postoperative weight bearing. Blood loss during operation and operation time were low and spontaneous failures were not observed. Two experimental studies in human cadaveric femurs concluded that fixation of the side plate with two proximal screws was safe even in three-part, unstable fractures.4,7 Application of a third screw to the side plate added
1001
only very little stability, application of four screws was not of any value. The explanation for the relatively few screws needed for adequate fixation of the DHS side plate in two-part fractures can be explained by the intrinsic stability of the ‘simple’ fracture pattern. Generally these patients present with the affected leg in external rotation, but without shortening. After simple reduction of the fracture by internal rotation only and subsequent fixation with a DHS, full weight bearing results in minimal load on the construct without varus stress. This is in contrast to unstable fractures where medial support fails and more sideplate screws or an intramedullary implant are required. Our study design is retrospective and therefore has limitations: length of surgical incision, operation time and blood loss were not reliably documented. Any statement on such secondary outcome parameters would be speculative, it needs a new and prospective setup. However, primary outcome parameters (i.e. fracture consolidation and secondary instability of the side plate) were reliably documented during follow up. Although the current study design produces ‘‘Class C’’-evidence and a direct comparison with a four-hole side plate is not performed, it clearly demonstrates that a two-hole side plate does not break out during early full weight bearing mobilisation. The traditional use of a longer DHS plate for this indication is therefore unnecessary and goes against the principle of ‘primum non nocere’ in the choice of our operative treatment. Now we know that a two-hole side plate is safe, any prospective, randomised study design to prove that a short side plate for this fracture type is better than a long one, could only produce differences in secondary outcome parameters. However, it is unlikely that a smaller and shorter operation results in more blood loss, operation time or postoperative complications. In other words, do we need to prove that one gets wet in the rain? We conclude that fixation of stable pertrochanteric femur fractures with a two-hole DHS is safe.
References 1. Bolhofner BR, Russo PR, Carmen B. Results of intertrochanteric femur fractures treated with a 135-degree sliding hip screw with a two-hole side plate. J Orthop Trauma 1999; 13:5—8. 2. Heyse-Moore GH. Fixation of intracapsular femoral neck fractures with a one-hole plate dynamic hip screw. Injury 1996;27:181—3. 3. Hoffmann R, Haas NP. Femur: proximal. In: Ru ¨edi TP, Murphy WM, editors. AO principles of fracture management. Stuttgart, New York: Thieme Verlag; 2000, p. 441—4.
1002
4. McLoughlin SW, Wheeler DL, Rider J, Bolhofner B. Biomechanical evaluation of the dynamic hip screw with two- and fourhole side plates. J Orthop Trauma 2000;14:318—23. 5. Regazzoni P, Ru ¨wer M. The dynamic ¨edi Th, Winquist R, Allgo hip screw implant system. Berlin/Heidelberg/New York/ Tokyo: Springer Verlag; 1985.
M.H.J. Verhofstad, C.v.d. Werken
6. Reich SM, Jaffe WL, Kummer FJ. Biomechanical determination of the optimal number of fixation screws for the sliding hip screw plate. Bull Hosp Jt Dis 1993—1995;53:43—4. 7. Yian EH, Banerji I, Matthews LS. Optimal side plate fixation for unstable intertrochanteric hip fractures. J Orthop Trauma 1997;11:254—9.
DHS osteosynthesis for stable pertrochanteric femur fractures with a two-hole side plate Michiel H.J. Verhofstada,*, Chris van der Werkenb a
Department of Surgery, St Elisabeth Hospital, P.O. Box 90151, 5000 LC Tilburg, The Netherlands Department of Surgery, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands
b
Accepted 13 October 2003
KEYWORDS Pertrochanteric fracture; Hip fracture; Dynamic hip screw; Osteosynthesis; Sliding hip screw; Operative technique
Summary The sliding hip screw is the implant of choice for the operative treatment of stable pertrochanteric femur fractures (AO classification 31-A.1). For this indication, a four-hole side plate with four bicortical screws is widely used to allow full weight bearing immediately after operation, but scientific support for the need of such a long side plate is not available. A shorter side plate is potentially less invasive. Therefore, we retrospectively evaluated all 148 consecutive patients (median age 80 years) with a stable pertrochanteric femur fracture who were treated between 1995 and 2001 with a dynamic hip screw (DHS) and a short (two-hole) side plate and immediate full weight bearing mobilisation. Although two wound hematomas and four wound infections occured, 145 fractures healed radiologically without implant-related complications within 6 months. Two hip screws cut out of the femoral head due to a poor position. In one patient, the side plate broke out after a fall out of bed on the fifth postoperative day. Pull off of any two-hole side plate during early full weight bearing mobilisation without further trauma was not observed. We conclude that fixation of stable pertrochanteric femur fractures with a two-hole DHS is safe. The traditional use of a four-hole DHS plate for this indication is therefore ‘over-treatment’ since it is more invasive. ß 2003 Elsevier Ltd. All rights reserved.
Introduction The dynamic hip screw (DHS), is an ideal implant for the operative treatment of stable pertrochanteric femur fractures (AO classification 31-A.13). For this indication, a four-hole side plate with four bicortical screws is traditionally recommended to allow immediate full weight bearing. However, scientific proof for this advice is scarce. Only one clinical *Corresponding author. Tel.: þ31-13-5392922; fax: þ31-13-5363660. E-mail addresses: [email protected], [email protected] (M.H.J. Verhofstad).
study has assessed the optimal length of the side plate in stable pertrochanteric femur fractures, suggesting that a two-hole side plate provides enough stability.1 The widespread use of a four-hole side plate in stable pertrochanteric femur fractures is merely based on tradition and needs reconsideration in this era of minimally invasive surgery and evidence based medicine ‘to do the patient no further harm than necessary’. The typical patient with a hip fracture is characterised by high age, significant co-morbidity and severe osteoporosis. These factors jeopardise the surgical treatment, which is
0020–1383/$ — see front matter ß 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.injury.2003.10.030
1000
M.H.J. Verhofstad, C.v.d. Werken
Incorrect fracture classification before operation or unfamiliarity with the protocol led to operative treatment with a four-hole DHS side plate or another implant in 22 patients. These and patients suffering from a pathological fracture (n ¼ 2) were excluded from analysis. Patients suffering early postoperative death were also excluded (n ¼ 15). Endpoints in the analysis were radiological fracture consolidation, an uncomplicated postoperative follow up of at least 6 months–—if radiological proof of consolidation was unavailable–—or secondary instability of the osteosynthesis. One hundred and forty-eight patients met the inclusion criteria. Their age, gender, trauma mechanism and wound or implant-related complications (with emphasis on secondary instability) were documented.
often underestimated and performed by relatively inexperienced residents. The patient’s compliance with after-treatment is low and non-weight bearing is practically impossible. Therefore, a two-hole side plate would be better, but only if stable enough. We retrospectively evaluated the results of treatment of a stable pertrochanteric femur fracture with a two-hole plate DHS.
Patients and methods In the surgical departments of the University Medical Centre, Utrecht and the St. Elisabeth Hospital, Tilburg (both in the Netherlands) patients with hip fractures are generally operated on by surgical residents under the supervision of a senior surgeon. According to the protocol, stable two part pertrochanteric femur fractures (AO classification 31-A.1) are treated with a dynamic hip screw (DHS; Mathys Medical, Bettlach, Switzerland) with a two-hole side plate with two 4.5 mm bicortical screws. Closed reduction on a fracture table and internal fixation as described in detail in the manufacturer’s manual5 are performed under fluoroscopic control and regional or general anaesthesia, with single antibiotic prophylaxis using preoperative intravenous administration of 2 g cefazolin. Thrombosis prophylaxis was given daily during the entire hospital stay with 2500 IU dalteparine subcutaneously. Postoperatively, all patients start immediate full weight bearing under the guidance of a physiotherapist. From the central hospital registration, all patients treated for pertrochanteric femur fractures (AO classification 31-A.1) with a DHS osteosynthesis between 1995 and 2001 were identified (n ¼ 284). Their hospital charts and radiographs were examined by one author. Only patients treated for a true 31-A.1 fracture were included (n ¼ 187).
Results Fig. 1 illustrates the distribution of age. The median age was 80.0 years (range 22—96) with 85% of patients over 65 years old. One hundred patients were female and 48 male. Three patients sustained a high-energy motorcycle accident and three patients fell during a bicycle race. The remaining 142 fractures were due to a simple fall, generally at home. One hundred and thirty-nine patients (94%) with a stable pertrochanteric femur fracture, treated with a DHS using a two-hole side plate fixed with two bicortical screws and immediate weight bearing afterwards, healed uneventfully. Two patients (1.4%) developed a wound haematoma, one required re-exploration. Four (2.7%) wound infections were found, one patient was treated with antibiotics, in three cases the wound was opened, resulting in good secondary healing in two patients and a fistula in one, which healed after implant
70
Number of patients
60 50 40 30 20 10 0 0-10
11-20
21-30
31-40
41-50
51-60
61-70
Decade
Figure 1 Distribution of age.
71-80
81-90 91-100
Pertrochanteric fractures and a two-hole DHS side plate
removal. None of the infections impaired fracture healing. Three implant-related complications were seen: cut out of the sliding screw due to poor placement was seen twice (1.4%), both patients were treated by prosthetic hip replacement. One two-hole DHS plate broke out (0.7%) in a 74-year old female who fell out of her hospital bed 5 days postoperatively. Spontaneous instability of the short, two-hole side plate was never observed in any of the remaining 145 patients (success rate: 100%).
Discussion In contrast to the widespread use of a DHS with a four-hole side plate for stable pertrochanteric femur fractures, we describe our excellent results in a series of patients with such fracture treated with a two-hole side plate. An identical surgical procedure for the sliding screw itself followed by the application of a shorter side plate has potential advantages. The surgeon requires less wound exposure and operative proceedings, blood loss and operation time can be reduced. Usage of a short side plate instead of a long one can only simplify and not hamper the operative technique. These benefits can be specifically important for the typical patient with a hip fracture: high age, osteoporotic bone and significant co-morbidity, resulting in a fragile equilibrium in physical and physiological performance, traditionally with a high peri-operative mortality. Unfortunately, these patients are frequently operated under suboptimal circumstances in a (semi-) acute setting by relatively inexperienced surgeons or residents. Therefore, a quick and minimally invasive surgical procedure is preferred, but only if the osteosynthesis itself is safe. Although numerous publications have been directed toward the optimal design, position and angle of the sliding screw, only five studies on the optimal length of the side plate exist.1,2,4,6,7 Of these few studies only two deal with stable pertrochanteric femur fractures.1,6 In the only available clinical study, Bolhofner1 reported excellent results in a series of 37 consecutive patients with a stable pertrochanteric fracture, treated with a two-hole DHS and immediate postoperative weight bearing. Blood loss during operation and operation time were low and spontaneous failures were not observed. Two experimental studies in human cadaveric femurs concluded that fixation of the side plate with two proximal screws was safe even in three-part, unstable fractures.4,7 Application of a third screw to the side plate added
1001
only very little stability, application of four screws was not of any value. The explanation for the relatively few screws needed for adequate fixation of the DHS side plate in two-part fractures can be explained by the intrinsic stability of the ‘simple’ fracture pattern. Generally these patients present with the affected leg in external rotation, but without shortening. After simple reduction of the fracture by internal rotation only and subsequent fixation with a DHS, full weight bearing results in minimal load on the construct without varus stress. This is in contrast to unstable fractures where medial support fails and more sideplate screws or an intramedullary implant are required. Our study design is retrospective and therefore has limitations: length of surgical incision, operation time and blood loss were not reliably documented. Any statement on such secondary outcome parameters would be speculative, it needs a new and prospective setup. However, primary outcome parameters (i.e. fracture consolidation and secondary instability of the side plate) were reliably documented during follow up. Although the current study design produces ‘‘Class C’’-evidence and a direct comparison with a four-hole side plate is not performed, it clearly demonstrates that a two-hole side plate does not break out during early full weight bearing mobilisation. The traditional use of a longer DHS plate for this indication is therefore unnecessary and goes against the principle of ‘primum non nocere’ in the choice of our operative treatment. Now we know that a two-hole side plate is safe, any prospective, randomised study design to prove that a short side plate for this fracture type is better than a long one, could only produce differences in secondary outcome parameters. However, it is unlikely that a smaller and shorter operation results in more blood loss, operation time or postoperative complications. In other words, do we need to prove that one gets wet in the rain? We conclude that fixation of stable pertrochanteric femur fractures with a two-hole DHS is safe.
References 1. Bolhofner BR, Russo PR, Carmen B. Results of intertrochanteric femur fractures treated with a 135-degree sliding hip screw with a two-hole side plate. J Orthop Trauma 1999; 13:5—8. 2. Heyse-Moore GH. Fixation of intracapsular femoral neck fractures with a one-hole plate dynamic hip screw. Injury 1996;27:181—3. 3. Hoffmann R, Haas NP. Femur: proximal. In: Ru ¨edi TP, Murphy WM, editors. AO principles of fracture management. Stuttgart, New York: Thieme Verlag; 2000, p. 441—4.
1002
4. McLoughlin SW, Wheeler DL, Rider J, Bolhofner B. Biomechanical evaluation of the dynamic hip screw with two- and fourhole side plates. J Orthop Trauma 2000;14:318—23. 5. Regazzoni P, Ru ¨wer M. The dynamic ¨edi Th, Winquist R, Allgo hip screw implant system. Berlin/Heidelberg/New York/ Tokyo: Springer Verlag; 1985.
M.H.J. Verhofstad, C.v.d. Werken
6. Reich SM, Jaffe WL, Kummer FJ. Biomechanical determination of the optimal number of fixation screws for the sliding hip screw plate. Bull Hosp Jt Dis 1993—1995;53:43—4. 7. Yian EH, Banerji I, Matthews LS. Optimal side plate fixation for unstable intertrochanteric hip fractures. J Orthop Trauma 1997;11:254—9.