|Year : 2021 | Volume
| Issue : 1 | Page : 63-71
Early Functional Outcome of Osteoporotic Intertrochantric Fractures in Elderly Managed with Proximal Femoral Nail and Proximal Femoral Nail Antirotation: A Comparative Study
Ankit Mittal, Simrat P.S Gill, Dinesh Kumar, Jasveer Singh, Harish Kumar, Ajay Rajput
Department of Orthopaedics, Uttar Pradesh University of Medical Sciences, Etawah, India
|Date of Submission||19-Oct-2020|
|Date of Decision||26-Jan-2021|
|Date of Acceptance||27-Jan-2021|
|Date of Web Publication||28-Apr-2021|
Department of Orthopaedics, Uttar Pradesh University of Medical Sciences (UPUMS), Saifai, Etawah - 206130, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Introduction: The choice of an implant in the management of intertrochanteric fractures of the femur has evolved from extramedullary devices to intramedullary ones. The proximal femoral nail antirotation (PFNA) that employs a helical blade is a recent and promising advancement but there is a paucity of data in the literature to prove its superiority over its predecessor nails in terms of functional gains. Aim: To compare the functional outcome of PFNA with proximal femoral nail (PFN). Materials and Methods: In this prospective randomized control study in osteoporotic elderly patients, 32 patients managed with PFNA were compared with a similar number treated with PFN and compared in terms of demography, intraoperative variables (duration of surgery, fluoroscopy time, and blood loss), time to union, and functional outcome utilizing Harris hip scores (HHS) at 6 and 12 months follow-up. Results: Both the groups were comparable in terms of age, gender, type of fracture, and Singh’s osteoporosis index. Although the duration of surgery and fluoroscopy time was significantly less in the PFNA group, it did not translate into any functional gains to the patients as the time to union and the HHS, at 6 and 12 months did not reveal any significant difference. Implant-related complications were significantly more in the PFN group with five patients having varus collapse, one having screw cut-out, two having screw pull-out, and one having Z-effect. Conclusion: Although there was no significant difference in terms of functional aspect, with lesser implant-related complication and shorter operative time, PFNA can prove to be a better substitute for the management of these fractures in osteoporotic elderly debilitated patients.
Keywords: Helical blade, Singh’s, osteoporotic index, varus collapse, Z-effect
|How to cite this article:|
Mittal A, Gill SP, Kumar D, Singh J, Kumar H, Rajput A. Early Functional Outcome of Osteoporotic Intertrochantric Fractures in Elderly Managed with Proximal Femoral Nail and Proximal Femoral Nail Antirotation: A Comparative Study. MAMC J Med Sci 2021;7:63-71
|How to cite this URL:|
Mittal A, Gill SP, Kumar D, Singh J, Kumar H, Rajput A. Early Functional Outcome of Osteoporotic Intertrochantric Fractures in Elderly Managed with Proximal Femoral Nail and Proximal Femoral Nail Antirotation: A Comparative Study. MAMC J Med Sci [serial online] 2021 [cited 2021 Jun 12];7:63-71. Available from: https://www.mamcjms.in/text.asp?2021/7/1/63/314874
| Introduction|| |
One of the most commonly occurring bone injuries among the elderly is the intertrochanteric fracture of the femur. Aging is an undefiable process and as the population ages, the incidence of hip fracture is anticipated to increase exponentially. Prolonged bed rest further worsens the morbidity and mortality after a hip fracture. Thus, early restoration of the patients to their preinjury status is imperative and this entailed internal fixation should be accepted as the standard of management as it provides acceptable reduction and facilitates early. The quality of internal fixation is significantly affected by factors such as intrinsic factors like osteoporosis and fracture comminution as well as by extrinsic factors like the quality of reduction, the type of implant, and the insertion techniques.,
The plethora of implants available in the market for internal fixation of these fractures bespeaks the evolving hunt for an ideal device. Once extensively used, sliding hip devices like the dynamic hip screw (DHS) are ill-suited to fix the unstable class of these fractures. They have the risk of penetrating the head and neck of the femur, and can break or bend or separate if the patient bears weight early especially in comminuted fractures., To overcome these limitations, in 1996, the (Arbeitsgemeinschaft für Osteosynthesefragen) or the Association of the Study of Internal Fixation (AO/ASIF) introduced the intramedullary devices such as the proximal femoral nail (PFN) that are biomechanically stronger and more rigid. Their intramedullary placement keeps them close to the mechanical axis of the femur, thereby decreasing the lever arm and bending movement on them.
The design of PFN has undergone many changes since its inception. To improvise, in 2003, the PFN was introduced with an antirotation system by AO/ASIF that was claimed to provide better rotation and angular stability with a single blade and was marketed as the proximal femoral nail antirotation (PFNA). It employs a helical blade, which is inserted by hammering and not by reaming the bone, resulting in compaction of the surrounding cancellous bone, thereby imparting additional hold, especially in an osteoporotic femur.
Owing to the theoretical advantage of PFNA in osteoporotic bone, this randomized prospective comparative study was conducted in an effort to understand and analyze the benefits of using PFNA over PFN.
| Materials and Methods|| |
This study was a 14-month prospective randomized comparative study from July 2018 to August 2019 conducted in our hospital after obtaining approval from the Institutional Ethics Committee. Patients with intertrochantric fractures in an osteoporotic femur with grade three or less, as analyzed by Singh’s Index on the AP view of the normal hip, were included in this study. A total of 80 patients, who satiated the inclusion and exclusion criteria, were enrolled and managed with close/open reduction with either PFN (Group PFN) or PFNA (Group PFNA) on the basis of block randomization with the random number table. Informed consent for surgery and participation in the study was obtained by all subjects. Minimum duration of follow-up was kept as 12 months.
The sample size was selected using the purposive sampling technique. Out of the total 72 patients enrolled, eight were lost to follow up and the results of 64 patients, with 32 in either group, were evaluated.
Patients, more than 50 years old, presenting with intertrochantric fracture femur, close or open (Gustilo grade 1 or 2), who were either grade 3, 2, or 1 on Singh’s osteoporosis index, and were able to walk prior to injury were enrolled in this study. Patients with more than 1-month-old injury, with significant concomitant ipsilateral lower extremity trauma, preoperative significant functional loss or comorbidity in ipsilateral lower extremity, nontraumatic disorder, pathological fractures, significant active infection anywhere in the body, unstable medical illness, on long-term corticosteroids, or who were unable to comply with rehabilitation protocol and to complete the forms were excluded from this study. Patients with pure subtrochanteric fractures and intertrochanteric fractures extending more than 5 cm below the lesser trochanter were also excluded. The minimum duration of follow-up was kept as 12 months.
The patients were evaluated as per the history, mode of injury, and anterio-posterior and lateral radiographs of the affected hip were done on admission. They were then put on skin traction over a Bohler-Braun frame. The A.O. alphanumeric classification was used to classify the fractures. Patients were taken up for surgery on the next elective OT day. Adequate blood transfusion and other supportive measures were given depending on the preoperative condition of the patient and blood loss during surgery. The immediate postoperative radiographs, and anteroposterior and lateral views of the operated hip were obtained. Outcome analysis was done following their surgical management with either PFNA or PFN.
The duration of surgery, fluoroscopy time, and the amount of blood loss were recorded intraoperatively.
Injectable antibiotics (cephalosporins) were started 1 hour before surgery and continued postoperatively for 2 to 3 days in all the patients. Oral cephalosporins were continued for the next 3 to 4 days. Low molecular weight heparin as an anti-deep vein thrombosis prophylaxis was used in a few of our patients.
All patients were operated under spinal/epidural anesthesia. Patients, in both the groups, were positioned on the fracture table with the ipsilateral arm elevated on a sling and uninjured leg in a leg holder. The injured leg was kept in around 10-15 degrees adduction. The entry point was taken at the tip or slightly lateral to the tip of the greater trochanter in the curved extension of the medullary cavity. In the lateral view, the entry point was in line with the axis of the intramedullary canal. The medullary cavity was reamed to a diameter that was at least 1 mm larger than that of the selected nail. The position of the tip of both the lag screw (in Group PFN) and the helical blade (in Group PFNA) was aimed at the center-center position, 5 to 10 mm below the joint level in both AP and lateral views. In group PFNA, the helical blade was hammered initially and later tightened with a hexagonal screw driver to achieve compression, whereas in group PFN, first the lag screw and then the antirotation screws were driven in using their respective screwdrivers, in line with the standard operative techniques. All nails were locked distally with both static and dynamic locking screws. We could achieve close reduction in all along with some manipulation with percutaneously placed instruments in few patients [Figure 8]. Immediate postoperative radiographs anteroposterior and lateral views of the operated hip were obtained in all patients.
|Figure 8 Intraoperative photographs showing the instrumentation of PFNA and some surgical steps of fixation with PFNA|
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In both groups, the patients were allowed to sit up in bed on the second postoperative day. Static quadriceps exercises were started on the second and third postoperative day. Sutures were removed after 10 to 14 days. Patients were mobilized non-weight bearing as soon as the pain or general condition permitted. Weight-bearing was determined by the stability of the fracture and adequacy of fixation and was delayed for patients with unstable or inadequate fixation.
All the patients were followed up at 2 weeks for suture removal followed by at 1 month, then monthly till 6 months or till fracture union, whichever is later, and finally at 12 months. Clinical evaluation and radiological evaluation for fracture union, implant position was done and complications like superficial and deep infection, thigh pain, varus-valgus deformity, limb length discrepancy were looked upon. Fractures were judged to be healed radiographically if bridging callus was evident on three to four cortices as noted on two views. Functional evaluation with Harris hip score (HHS) was done at 6 and 12 months follow-up.
One-way ANOVA test was used to analyze the difference of means for different parameters. The test was referenced for a two-tailed P-value and 95% confidence interval was constructed around sensitivity proportion using a normal approximation method. The Fischer’s exact test was used for the comparison of paired categorical variables. Chi-square test was employed to calculate the P-value with more than two variables. SPSS software was used to perform statistical analyses. A P-value of <0.05 was considered statistically significant.
| Results|| |
A final evaluation of 32 patients in each group (PFN and PFNA) was made. The mean age of patients in both the groups was comparable (76.84 ± 10.75 years in PFN group and 77.63 ± 11.52 in PFNA group). Both the groups were also comparable in terms of gender distribution, Singh’s osteoporosis index, and the type of fracture as per the AO classification. The demographic profile of both the groups is depicted in [Table 1].
Coming to the intraoperative parameters, the mean total duration of surgery (69.28 ± 12.86 min in PFN group vs 62.22 ± 11.68 min in PFNA group) as well as the mean fluoroscopy time (71.72 ± 11.58 s in PFN group vs 64.56 ± 11.26 s in PFNA group) was higher in Group PFN and the results of both the parameters were statistically significant. Mean blood loss was also more in group PFN (103.91 ± 23.61 mL) than in group PFNA (100.31 ± 23.31 mL) but the result was statistically not significant [Table 2].
All the fractures in both the groups united in our study and mean time to union were comparable in both the groups (4.44 ± 1.13 months in PFN group and 4.22 ± 0.87 months in PFNA group) [Table 3]; [Figure 3],[Figure 4],[Figure 6], and [Figure 7].
|Figure 3 Case 1: Intertrochanteric fractured femur. (A) Preoperative AP and lateral radiograph. (B) Immediate postoperative AP and lateral radiograph after fixation with PFN. (C) Six months follow-up AP and lateral radiograph showing fracture union. (D) One year follow-up radiograph|
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|Figure 4 Case 2: Intertrochanteric fractured femur. (A) Preoperative AP and lateral radiograph. (B) Immediate postoperative AP and lateral radiograph after fixation with PFN. (C) Six months follow-up AP and lateral radiograph showing fracture union. (D) One year follow-up radiograph|
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|Figure 6 Case 3: Intertrochanteric fractured femur. (A) Preoperative AP and lateral radiograph. (B) Immediate postoperative AP and lateral radiograph after fixation with PFNA. (C) One year follow-up radiograph|
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|Figure 7 Case 3: Intertrochanteric fractured femur. (A) Preoperative AP and lateral radiograph. (B) Immediate postoperative AP and lateral radiograph after fixation with PFNA. (D) One year follow-up radiograph|
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Group PFNA patients fared better functionally in terms of the HHSs evaluated at 6 months (75.28 ± 11.70 in PFN group and 78.75 ± 10.05 in PFNA group) and 12 months (84.38 ± 09.63 in PFN group and 86.50 ± 08.16 in PFNA group) but the results were statistically not significant at both the durations [Table 3]; [Figure 1],[Figure 2],[Figure 5], and [Figure 9].
|Figure 2 A comparison of Harris hip scores (HHS) at 12 months follow-up.|
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Varus collapse was observed in five cases with PFN and two cases with PFNA. Limb length shortening of more than 1 cm was observed in all these seven cases. In the patients treated with PFN, one had screw cut-out, three had screw back out, and one had Z-effect and required some forms of revision surgeries. None of the patients of the PFNA group had these complications. None of the patients in any of the groups had reverse Z-effect or implant breakage. We observed a statistically significant fewer implant-related complication rate in the PFNA group as compared to the PFN group [Table 4].
Other minor postoperative complications included superficial infection, calcification at the tip of the greater trochanter, sensitivity over tensor fascia lata, and medial thigh pain, and none of these affected the functional outcome and the difference was statistically insignificant between the groups. None of the cases had a deep infection in our series [Table 5].
| Discussion|| |
The management of unstable intertrochanteric fractures has posed a considerable challenge to the orthopedic surgeon for years together and osteoporosis further worsens the situation. Biomechanical studies have demonstrated that patients with osteoporosis are predisposed to implant failure because of more incidence of screw migration in the proximal femur. Inferior outcomes with osteoporosis have been shown by clinical studies. Therefore, in an attempt to strengthen the fixation in osteoporotic intertrochantric fractures, various attempts like cement augmentation and innovations in implant design have been employed.
The discovery of a helical blade instead of screws with a cephalon-medullary nail was one such attempt based on its biomechanical superiority in the setting of osteoporosis. The helical blade does not require reaming for insertion and thus does not take out the vital bone stock from the femoral head. It rather requires hammering for insertion that compacts the cancellous bone around it, imparting a superior purchase with higher resistance to varus collapse as well as rotational stress.
The present study was thus aimed at observing whether this biomechanical advantage of helical blades over the screws translates into clinical gains in osteoporotic intertrochanteric fractures or not. Our results showed no statistically significant differences in terms of functional outcomes as analyzed by the HHSs at 6 and 12 months follow-up. However, the overall complication rate was significantly less in the PFNA group than in PFN group. This is consist with other recent studies. Bajpai et al. in their study found no significant difference in the HHSs of the two groups at 18 months follow-up. Kadam et al. reported initially higher HHS with PFNA but almost similar HHS in the two groups at 6 months follow-up. Sharma et al., who utilized HHS and Parker’s mobility score, could not find any significant difference in the functional outcome at 9 months follow-up but reported a significantly lower complication rate in the PFNA group than in the PFN group, in line with our study. A recent study, by Santharam et al., which compared a newer implant, PFNA2, a modification of PFNA for the Asian population, with PFN also reported almost similar functional outcomes at the final follow-up of 6 months.
Although the functional outcomes were similar, in our study, PFNA did have an edge over its predecessor in terms of intraoperative parameters. With significantly less operating time and fluoroscopy time, PFNA could prove to be a time savior in institutions burdened with heavy patient load. Less average blood loss was also observed in the PFNA group, though it was statistically not significant. Sharma et al. observed the average time of surgery to be roughly 40 minutes shorter with PFNA than with PFN and no significant difference in the amount of blood loss between the two groups. Santharam et al. found the mean duration of surgery to be less with PFNA2 than with PFN but the difference did not come out to be statistically significant. Kadam et al. found a significantly lower blood loss in the PFNA group than in the PFN group attributed it to decreased duration of surgery (also statistically significant in their study) and smaller surgical incision for placement of PFNA blade as compared to that needed for insertion of lag and derotation screws in PFN group.
Significantly lower complication rates were found in our study with PFNA than with PFN. Although varus collapse and more than 1 centimeter limb length shortening was seen in two patients with PFNA, there was no reported case of blade cut-out, pull-out, Z-effect, or reverse Z-effect with PFNA. Osteoporosis predisposes to implant failures in these fractures, especially if the device is malpositioned. The helical blade by avoiding bone loss caused by reaming and by radially compacting the cancellous bone around its flutes, could possibly offer the observed advantages. Sharma et al. also reported implant failure in three of the eight cases with PFN and none of the 13 cases with PFNA in patients with definite osteoporosis.
Our study was carried out with a small sample size. Long-term complications such as implant failure, peri-implant fractures, hip joint complications, or others if any, of these implants cannot be commented upon due to a short period of follow-up of 1 year. Intraoperative factors such as the accuracy of reduction and implant placement were also not compared between the groups. We relied upon the Singh’s index rather than dual energy X-ray absorptiometry as a determinant of osteoporosis that makes our inference subjective.
| Conclusion|| |
To conclude, both PFN and PFNA are preferred modalities of management of intertrochanteric fractures. They offer similar functional results once the fracture has united. However, with reduced implant-related complications and shorter operative time, PFNA can prove to be a boon for osteoporotic, elderly debilitated patients.
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], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]