|Year : 2020 | Volume
| Issue : 1 | Page : 31-38
Functional outcome and revision rate of proximal femoral nail antirotation versus dynamic hip screw for osteoporotic intertrochanteric femur fracture: A systematic review and meta-analysis
Sherly Desnita Savio, I Made Arya Susila, Cokorda Gde Oka Dharmayuda
Department of Orthopaedics and Traumatology, Faculty of Medicine Udayana University, Sanglah General Hospital, Denpasar, Indonesia
|Date of Submission||01-Apr-2020|
|Date of Acceptance||20-Apr-2020|
|Date of Web Publication||26-Jun-2020|
Dr. Sherly Desnita Savio
Department of Orthopaedics and Traumatology, Faculty of Medicine Udayana University, Sanglah General Hospital, Jl. Diponegoro, Dauh Puri Klod, Denpasar 80113, Bali
Source of Support: None, Conflict of Interest: None
Introduction: Intertrochanteric femur fracture in elderly presents a challenge as the source of morbidity if not well-treated. This study investigates the functional outcome and revision rate of two of the most common treatments of choice for this condition, proximal femoral nail antirotation (PFNA) and dynamic hip screw (DHS), while furthermore investigate the secondary functional outcome of the two procedures if proceeded to conversion to total hip arthroplasty (CTHA). Methods: A systematic search was conducted based on PRISMA guideline to identify relevant studies through PubMed, Google Scholar, and Cochrane database. A total of 9 studies (2.251 patients) were included, divided into three meta-analysis, processed using Review Manager 5.3. Results: For primary Harris Hip Score (HHS), 3 articles were included, with a total sample of 371 patients (184 PFNA vs. 187 DHS). For primary HHS, the mean HHS at 12-month follow-up for PFNA (n = 184) was 77.77, as for DHS (n = 187) was 78.33, indicating no significant difference (P = 0.73). For the revision rate, 4 articles were included, with a total of 1550 samples (784 PFNA vs. 766 DHS). The mean revision rates for PFNA (n = 784) was 2.68%, as for DHS (n = 766) was 2.48%, indicating no significant difference (P = 0.61). For secondary HHS after CTHA, two articles were included, with a total amount of 332 patients (142 PFNA vs. 190 DHS). In terms of secondary HHS after CTHA, the mean HHS 12-month postoperatively for PFNA (n = 142) was 83.97, as for DHS (n = 190) was 83.65, indicating no significant difference (P = 0.59). Conclusion: The current systematic review and meta-analysis suggest that PFNA and DHS both have comparable primary functional outcome, revision rate, and post-CTHA secondary functional outcome.
Keywords: Dynamic hip screw, intertrochanteric femur fracture, proximal femoral nail antirotation
|How to cite this article:|
Savio SD, Susila I M, Dharmayuda CG. Functional outcome and revision rate of proximal femoral nail antirotation versus dynamic hip screw for osteoporotic intertrochanteric femur fracture: A systematic review and meta-analysis. J Orthop Traumatol Rehabil 2020;12:31-8
|How to cite this URL:|
Savio SD, Susila I M, Dharmayuda CG. Functional outcome and revision rate of proximal femoral nail antirotation versus dynamic hip screw for osteoporotic intertrochanteric femur fracture: A systematic review and meta-analysis. J Orthop Traumatol Rehabil [serial online] 2020 [cited 2020 Sep 23];12:31-8. Available from: http://www.jotr.in/text.asp?2020/12/1/31/287709
| Introduction|| |
Intertrochanteric femur fracture presents a challenge as the source of morbidity if not well-treated. As there are only a few cases of intertrochanteric femur fractures where patients receive conservative treatment, the standard therapies for this pathology include osteosynthesis using dynamic hip screws (DHSs), intramedullary nails (i.e., proximal femoral nail antirotation [PFNA]), or hip arthroplasty. In elderly population, the high rate of osteoporosis adds the difficulty in management, resulting in high morbidity and mortality in association with this injury.
Since its introduction in 1964, DHS remained the standard implant of choice for many years due to its low rate of nonunion and fixation failure. However, as the time goes, many surgeons reported high reoperation rate using DHS. Therefore, DHS started to be abandoned by surgeons due to some commonly found postoperative problems, such as excessive collapse of the fracture site and varus displacement, leading to quite a high rate of revision. This is also supported by several literatures stating that newer technique such as PFNA is superior than DHS in terms of clinical and functional outcome, adding to the increased use of this technique for intertrochanteric femur fracture., However, this statement varies as there are also some literatures stating that DHS offers similar outcome to PFNA, despite the fact that it results in more blood loss and longer surgical time.
As a common method of revision, there is a general agreement that failed PFNA or DHS fixations of intertrochanteric fractures should be treated with a conversion to total hip arthroplasty (CTHA) whenever possible. Prior studies have reported that CTHA was a successful procedure that could be used to treat failed DHS or PFNA fixations of intertrochanteric fractures. However, it has been unclear whether there are differences in the success rates for converting PFNA or DHS to a THA, especially in terms of secondary functional outcome after CTHA.,
As far as we observe, there has not been any meta-analysis to objectively compare the outcomes of these two procedures. Therefore, this study aims to investigate the functional outcome and revision rate of two of the most common treatments of choice for intertrochanteric femur fracture, PFNA and DHS, while furthermore investigate the secondary functional outcome of the two procedures if proceeded to CTHA. By drawing objective conclusion through systematic review and meta-analysis, the authors hope that this study will enable surgeons to choose the most appropriate treatment for intertrochanteric femur fractures by considering each treatment's functional outcome, revision rate, secondary functional outcome, and complications.
| Methods|| |
The study design was a systematic review and meta-analysis over numbers of randomized controlled trials and nonrandomized comparative studies. A systematic search was conducted from October to November 2019 to identify relevant studies through PubMed, Google Scholar, and Cochrane database based on PRISMA guideline [Figure 1]. The keywords used were:
- “Proximal Femoral Nail Antirotation” AND “Dynamic Hip Screw” AND “Intertrochanteric Femur Fracture.”
Those data were then manually scanned and reviewed by all authors with the inclusion criteria: (1) the studies included a comparative design for PFNA versus DHS, (2) patients aged minimum 50 years old with osteoporotic intertrochanteric femur fracture, (3) the studies reported a desirable outcome with continuous variable, as measured by Harris Hip Score (HHS), and dichotomous variable as measured by revision rate, and (4) the studies in English. Exclusion criteria were those with fractures other than intertrochanteric femur fracture, infection, or congenital deformity. Intertrochanteric femur fractures not in osteoporotic population were excluded. Noncomparative studies, nonhumanin vivo andin vitro were also excluded. [Table 1] describes population-intervention-comparison-outcome method for defining the inclusion and exclusion criteria.
|Table 1: Population-intervention-comparison-outcome table describing inclusion and exclusion criteria|
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The data extraction was collected under basic characteristics and main outcomes presented as the HHS and revision rate. In each study, mean difference for continuous outcome and odds ratio for dichotomous outcome with a 95% confidence interval (CI) was calculated using Review Manager (RevMan) (Computer program, version 5.3. Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2014). Fixed effect model was used when the heterogeneity was <50%, whereas random effect model was used when the heterogeneity was >50%.
| Results|| |
A total of nine studies (2.251 patients) were included, divided into three meta-analysis. Eight studies are Cohort Retrospective design (Level III evidence), while one article is prospective randomized controlled trial (Level I evidence) [Table 2]. Critical appraisal of all studies included were conducted based on Joanna Briggs Institute Scoring System, showing no study had more than 3 invalid parameters [Table 3].
For primary HHS, 3 articles were included into the analysis [Table 4], with a total sample of 371 patients, where 184 patients (49.6%) were treated with PFNA and 187 patients (10.4%) were treated with DHS. The mean age for PFNA group was 72.76–74.34 years old, as for DHS group was 69.33–77.3 years old. Female is more often affected than male, and DHS is slightly more often used than PFNA. Fracture types treated range from AO A1 to A2 intertrochanteric femur fracture. PFNA seems to benefit with less blood loss (116 ± 48.6 cc) compared to DHS (207.24 ± 81.3 cc). In terms of operation time, PFNA also takes shorter duration. For the meta-analysis of HHS, random effect model was used for continuous outcome. The mean HHS at 12-month follow-up for PFNA (n = 184) was 77.77, as for DHS (n = 187) was 78.33. [Figure 2] shows there was no significant difference in terms of HHS between the two procedures (heterogeneity, I2 = 99%; WMD: −1.02; 95% CI: −6.72–4.69; P = 0.73. Other outcome measures are Koval Score, visual analog scale, leg length discrepancy (LLD), Short Form-12 Physical Composite Scale, and Mental Composite Scale, where the two procedures seem to be comparable. DHS seems to have higher complication rate (up to 34.82%), with the most common complication of femoral shaft fracture after implant removal in both procedures. The other complications described are lateral cortex fracture, LLD, malunion, varus collapse, screw cut-out, implant failure, lateral migration of screw, and infection. The three articles have follow-up period of 12–38 months.
|Table 4: Study characteristics for functional Harris hip score assessment of primary proximal femoral nail antirotation versus dynamic hip screw|
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For the revision rate, 4 articles were included into the analysis [Table 5], with a total of 1550 samples, consisting of 784 patients (50.58%) who were treated using PFNA and 766 patients (49.42%) who were treated using DHS. The age of samples for the two procedures ranges from 57 to 99 years old, with female being much more often affected than male. Fracture types treated range from AO A1 to A3 intertrochanteric femur fracture. For the meta-analysis of revision rate, random effect model was used for dichotomous outcome. The mean revision rates for PFNA (n = 784) were 2.68%, as for DHS (n = 766) were 2.48%. [Figure 3] shows there was no significant difference in terms of revision rate between the two procedures (heterogeneity, I2 = 57%; WMD: 1.37; 95% CI: 0.40–4.69; P = 0.61. Some of the causes for revision were loss of position of the implant/fracture, intractable pain, cutting out of the screw in osteoporotic bone, hematoma, and infection. The follow-up period ranges from 12 to 120 months.
|Table 5: Study characteristics for revision rate assessment of primary proximal femoral nail antirotation versus dynamic hip screw|
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For secondary HHS after CTHA, two articles were included into the analysis [Table 6], with a total amount of 332 patients, where 142 patients (42.77%) were treated with PFNA, and 190 patients (57.23%) were treated with DHS. The age of samples for PFNA ranges from 70.07 to 76.93 years old, as for DHS was 68.57–74.96 years old. Female is more often affected than male, and DHS is more often the initial procedure before CTHA compared to PFNA. The mean secondary HHS 12-month postoperatively for PFNA group (n = 142) was 83.97, as for DHS group (n = 190) was 83.65. Meta-analysis with fixed effect model for continuous outcome was conducted. [Figure 4] shows there was no significant difference in terms of secondary HHS after CTHA between the two procedures (heterogeneity, I2 = 0%; WMD: 0.17; 95% CI: −0.44–0.77; P = 0.59. The complication rate seems to be higher in DHS group, with periprosthetic fracture being the most common complication in both groups. Other complications mentioned are dislocation, heterotrophic ossification, infection, pulmonary embolism, nerve injury, limb length discrepancy, heterotopic ossification, and aseptic loosening. The mean follow-up period was 48–87.28 months.
|Table 6: Study characteristics for functional Harris hip score assessment after conversion to total hip arthroplasty due to the failure of primary proximal femoral nail antirotation versus dynamic hip screw|
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|Figure 4: Analysis of Harris Hip Score 12-month postconversion to total hip arthroplasty|
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| Discussion|| |
As one of the most common types of osteoporotic fragility fracture, intertrochanteric femur fracture accounts for approximately half of all hip fractures in elderly, and this incidence is expected to double in the next 25 years due to higher life expectancy., Furthermore, 50%–60% of these fractures are unstable with deficient lateral wall, needing further surgical intervention. Although similarly aiming at building a stable construct to decrease complications, the treatment of choice for this pathology remains controversial. Two of the most commonly discussed treatments are extramedullary and intramedullary fixations.
The goals of fixation are to achieve early mobilization, timely union, and restoration of the optimal functional outcome as well as minimalizing complications and attaining healing. Many internal factors also play role in the outcomes, such as the age of the patients, general health condition, and existing comorbidities. However, the choice of implant should still always be based on its availability and affordability, as well as considering each individual patient's characteristics. During the 1980s, DHS was used widely as the standard implant of choice, due to its unique feature of controlled collapse at fracture site and low rate of nonunion. However, many surgeons reported high reoperation rates using DHS due to fixation failure, especially when used in unstable fractures. To overcome these issues, various modifications and innovations have been made including the launch of PFNA, with the hope of better postoperative results. With the advantage of closed insertion through a small incision and a shorter lever arm, intramedullary fixation using PFNA is believed to reduce the risk of implant fatigue failure. It also appeared to be superior due to its ability to disperse and reduce the concentrated stress secondary to biomechanical characteristics of the intramedullary fixation.,
Some cohorts and clinical trials have compared the efficacy of both procedures, though the result varies. Through this systematic review and meta-analysis, we prove that both procedures are equally effective in terms of 12-month HHS, which means that both procedures are comparable in terms of postoperative pain, function, deformity, and range of motion. However, careful precautions should be made especially for DHS. Despite its advantage of being more affordable than PFNA, fracture displacement might happen secondary to the pull of the iliopsoas, gluteus medius, and short external rotator muscles on the proximal fragment, especially in unstable fractures. Other complications that should be monitored are varus collapse, retroversion, future deformity, or nonunion when a force is transmitted to the fracture line. Furthermore, caution should be taken into an account when inserting the implant, as fracture of the lateral wall could convert a stable intertrochanteric femur fracture into unstable one. Under these circumstances, applying a DHS device could further increase this risk of complications, despite good initial reduction, and satisfactory fixation. However, in unstable osteoporotic fractures stabilized with PFNA implant, that complication could also occur.
In terms of blood loss, DHS results in more blood loss due to its longer skin incision (10 cm) compared to PFNA (5 cm). As for the duration of surgery, the amount of screws applied might be influential, as well as the learning curve difference in each different surgeons. In this case, blood loss and surgical time can be reduced using smaller DHS plate with less number of screws in the femoral shaft. This be can put into consideration when choosing appropriate treatment for elderly, where less blood loss and shorter duration of surgery plays roles in preventing complications.
Some modifications can also be made to improve the efficacy of DHS, such as the addition of a trochanter stabilizing plate or Medoff sliding plate to the DHS construct. However, though it is proven to be effective in preventing medicalization of the femur, this method was not proven to lower the failure rate of the implant in terms of the requirements for revision surgery. Despite all modifications mentioned earlier, placement of the lag screw accurately in the center of the femoral head and careful postoperative management play an important role in the success of the device.
In addition, the working length of the DHS in elderly osteoporotic patients could also have a potential effect on the stiffness, gap motion, and resistance to fatigue. On the other hand, long PFNA implants have also shown better results than short PFNA implants. Increasing the implant length at the level of the fracture line enables a larger area of stress distribution on the locking plate and decreases the stress at the fracture site, therefore more appropriate for osteoporotic fractures.
Despite the result of our study that proves comparable secondary outcome after CTHA in both groups, a study by Zeng et al. stated that prior DHS-treated patients receiving CTHA tended to have less resistance to periprosthetic fractures. This may be caused by the fact that patients with stable intertrochanteric fractures who are being treated with DHS tended to have poorer bone quality caused by stress shielding, compared to patients undergoing PFNA. On the other hand, a study by Yu, et al. stated that patients treated with PFNA can have poor bone quality compared with patients treated with DHS, due to the destruction of the femoral marrow cavity and the disuse atrophy of proximal femoral part. In addition, prior treatment with PFNA might damage the abductor mechanism due to most minimally invasive incisions, as the nail is inserted at the tip of the greater trochanter (the area of insertion of the abductor tendon). Furthermore, abductor mechanism failure after CTHA can cause recurrent remarkable lateral pain and dislocations. However, it is also possible that the fractures treated with DHS may have been more complex than those treated with PFNA, vice versa, which might have eventually led to more malunions, fractures, and complications in one group compared to another.,
In terms of surgical methods, both cemented and uncemented CTHA designs are being successfully used for the treatment of failed fixations, despite the fact that uncemented CTHAs are more commonly offered to youthful patients. Moreover, previous studies had evaluated the outcome of the cemented and uncemented CTHA, and reported no difference between cemented and uncemented CTHA was observed with respect to stem performance.,
This study has several limitations: (1) Most of the studies included are of Level III evidence. (2) The heterogeneity of the studies included is high, especially for primary 1-year HHS. (3) Due to the limitation of studies, all types of intertrochanteric femur fractures were taken into account. This may contribute to the heterogeneity of the studies involved, considering that nowadays PFNA is more preferred than DHS for unstable intertrochanteric femur fractures. However, to the best of our knowledge, this study is the first to formulate meta-analysis on this matter. Furthermore, through analysis on the revision rate and secondary functional outcome adds points to this study. In the future, it is hoped that this study might be influential for future study, conducting well-designed trials with bigger amount of samples.
Through this study, we can conclude that PFNA and DHS can both be considered in osteoporotic intertrochanteric femur fracture, as the two procedures offer similar 1-year functional outcome and revision rate. However, PFNA may benefit with less blood loss and operation time. Some potential revision causes, such as peri-implant femoral fracture, infection, and implant failure should always be monitored perioperatively. Furthermore, when CTHA is indicated for revision, the two procedures offer comparable secondary functional outcome.
| Conclusion|| |
The current systematic review and meta-analysis suggest that PFNA and DHS both have comparable primary functional outcome, revision rate, and post-CTHA secondary functional outcome.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]