Comparitive Study between Proximal Femoral Nailing and Dynamic Hip Screw in Intertrochanteric Fracture of Femur *

Background: Internal fixation is appropriate for most intertrochanteric fractures. Optimal fixation is based on the stability of fracture. The mainstay of treatment of intertrochanteric fracture is fixation with a screw slide plate device or intramedullary device. So it is a matter of debate that which one is the best treatment, dynamic hip screw or proximal femoral nailing. Method: A prospective randomized and comparative study of 2 years duration was conducted on 60 patients admitted in the Department of Orthopedics in our hospital with intertrochanteric femur fracture. They were treated by a dynamic hip screw and proximal femoral nail. Patients were operated under image intensifier control. The parameters studied were functional outcome of Harris hip score, total duration of operation, rate of union, amount of collapse. These values were statistically evaluated and two tailed p-values were calculated and both groups were statistically compared. Result: The average age of our patient is 67.8 years. Among the fracture, 31% were stable, 58% were unstable, 11% were reverse oblique fracture. The average blood loss was 100 and 250 ml in PFN and DHS group, respectively. In PFN there was more no. of radiation exposure intra-operatively. The average operating time for the patients treated with PFN was 45 min as compared to 70 min in patients treated with DHS. The patients treated with PFN started early ambulation as they had better Harris Hip Score in the early period (at 1 and 3 months). In the long term both the implants had almost similar functional outcomes. Conclusion: In our study we have found that the unstable pattern was more common in old aged patients with higher grade of osteoporosis and PFN group has a better outcome in this unstable and osteoporotic fracture. PFN group has less blood loss and less operating time compared to DHS group. In PFN group patients have started early ambulation compared to DHS group.


Introduction
Extracapsular fractures (intertrochanteric and sub-trochanteric fractures) primarily involve cortical and compact cancellousbone.Because of the complex stress configuration in this region and its nonhomogeneous osseous structure and geometry, fractures occur along the path of least resistance through the proximal femur [1].
Gulberg et al. has predicted that the total number of hip fractures will reach 2.6 million by 2025 and 4.5 million by 2050 [2].In 1990 26% of all hip fractures occurred in Asia whereas this figure could rise to 37% in 2025 and 45% in 2050 [3].
The various treatment options for intertrochanteric fractures are operative and non-operative.The non-operative method was used to be a treatment of choice in early 19th century when the operative technique was not evolved enough to do stable fixation.Non-operative treatment should only be considered in non-ambulatory or chronic dementia patients with pain that is controllable with analgesics and rest, terminal diseases with less than 6 weeks of life expectancy, unresolved medical comorbidities that preclude surgical treatment, active infectious disease that itself is a contraindication for insertion of a surgical implant and incomplete pertrochanteric fractures diagnosed by MRI.Intertrochanteric fractures can be treated by either DHS or PFN .The intramedullary devices offer certain distinct advantages: 1.The implant itself serves as a buttress against lateral translation of the proximal fragment.
2. The intramedullary location of the junction between the nail and lag screw makes the implant stronger at resisting the binding force.
3. The intramedullary device has a reduced distance between the weight bearing axis and the implant that is a shorter lever arm.
4. An intramedullary device bears the bending load which is transferred to the intramedullary nail and is resisted by its contact against the medullary canal (load sharing device).
5. The intramedullary hip screw is a more biological method of fixation.
Hence we conducted a study in our rural set up to compare the result of treatment of these fractures by either of those two methods that is proximal femoral nailing and dynamic hip screw.

Materials and Methods
A prospective randomized and comparative study was conducted on the patients admitted in the Department of Orthopedics of BSMC&H.Our study population mainly consisted 60 patients (30 in each group) with more than 50 years of age.The study period was about 2 year from July 2011 to June 2013.Eligibility criteria for the patients included in the study were as follows: 1) Patients who were in the age group of more than 50 years of either sex, 2) Intertrochanteric fracture type 31-A2, 31-A3 (OTA classification) without any systemic or psychiatric illness, 3) patients fit for anaesthesia.
The exclusion criteria were 1) Patients unfit for the surgery, 2) with compound or pathological fractures, 3) admitted for re-operation 4) those who have not given written consent for surgery.
The present study was undertaken in patients more than 50 years of age with the following objectives 1.To compare the Dynamic Hip Screw and the Proximal Femoral Nail method of fixation in intertrochanteric fracture of femur in the adults with respect to intra operative parameters (total duration of surgery, intraoperative blood loss and intraoperative complication).
2. To compare the functional outcome with respect to union of the fracture, functional return, and complications in the two groups.
3. To determine which implant would be ideal for which fracture type so as to provide the best results with the least complications.
4. To study the long-term follow up of the two groups with respect to any residual impairment of function, chronic infection and overall tolerability of implant.
The important parameters assessed were:  Clinical: 1. Wound condition 2. Shortening 3. Harris hip score  Radiological: 1. Union 2. Amount of collapse 3. Complication like screw cut out After obtaining ethical clearance from the institutional Ethics committee, study was conducted among the study populations after obtaining written informed consent in accordance with the Ethical standards of the 1964 Declaration of Helsinki as revised in 2000.The relevant information collected from all patients including history, general and systemic examination findings.Initial radiograph of the hip joint was conducted besides routine pre anesthetic investigations.The 60 patients were divided in to two groups, 30 in each.The patients under group A were treated by proximal femoral nailing (Figures 1 and  2) and patient under group B were treated by Dynamic hip screw (Figures 3 and 4).Implant either DHS or PFN was randomly selected by operating surgeon.All the cases included in our study were operated as soon as possible.The average delay of surgery in our study was 3 days.
For PFN Nail diameter was determined by measuring diameter of the femur at the level of isthmus on an AP X-ray, Neck shaft angle was measured in unaffected side in AP X-ray using goniometer and a standard length PFN (250 mm) was used in all our cases.
For DHS Length of compression screw was measured from tip of the head to the base of greater tronchanter on AP view X-ray subtracting magnification.Neck shaft angle was determined using goniometer on X-ray AP view on unaffected side and length of side plate length of the side plate was determined to allow purchase of at least 8 cortices to the shaft distal to the fracture.
All patients in our study were treated with physical methods such as early mobilization, manual compression of the calf and elastic stockings.Patients were encouraged ankle and calf exercises from day one and mobilized nonweight bearing from the second post-operative day depending upon the physical condition of the patient.All drains were removed by 24 h.The wounds were inspected on the 3rd and 6th post-operative day.Stitches were removed on the 11th day.Patients were followed up at one monthly interval till fracture union and then at 6 monthly interval for 1 year and then at yearly interval.

Results
The study involved 60 confirmed cases of intertrochanteric femurfracture of either sex from July 2011 to June 2013.Out of 60 cases, 30 were treated by proximal femoral nailing (group A) (Figures 1 and 2) and 30 were treated by dynamic hip screw (group B) (Figures 3 and  4).
In our study maximum age was 79 years and minimum was 51 years.The average age was 67.8 years.In both groups A and B 13 were male and 17 were female patients.
In either group, 17 were OTA 31-A2 and 13 were 31-A3.The results were statistically analyzed and the two tailed p values were evaluated.
The Singh's index for osteoporosis showed that there were 26 patients with grade 4 and above (43.33%)(Table 1 and Chart 1).

Duration of Surgery
Duration of surgery was more for DHS compared to PFN.The duration of surgery as calculated from the time of

Blood Loss during Surgery
Blood loss was measured by mop count and collection in suction drain.The average blood loss in the P.F.N group was 116 ml and in the DHS group was 213 ml.blood loss is less in PFN which is statistically significant, p value < 0.0001 (Table 2).

Intraoperative Complications PFN
There was no failure to achieve close reduction among all 30 patients.There was no iatrogenic fracture of lateral cortex among all 30 patients.In 3 of 30 cases, we failed to put anti-rotation screw.It could not be accommodated in the neck after putting neck screw.We had no difficulties in distal locking.There were no instances of drill bit breakage or jamming of nail (Table 3).

Intraoperative Complications DHS
In 2 of 30 cases there was improper placement of Richard's screw.Difficulties were encountered in reverse oblique fractures as the fracture site extended to entry point.There was varus angulation in 2 of 30 patients.On table surgeon had to switch to PFN in 2 cases in reverse oblique fracture.These cases were considered with PFN group (Table 4).

Infection
There were 2 cases of infection seen in the D.H.S group.They were seen within 13 days of surgery and were treated by local debridement and antibiotic and did not require implant removal (Table 2).

Sliding
The sliding of both groups was compared at the end of 1 year on the X-rays as described by Hardy et al. [3], there was an average of 5.53 mm of sliding in the P.F.N group as compared to 8.10 mm in the D.H.S group (p < 0.0001).

Shortening
The average shortening in the P.F.N group was 5.35 mm as compared to 9.62 mm in the D.H.S group.So, shortening is less in PFN group which is statistically significant.p value < 0.0001 (Table 2).

Implant Failure
There was 1 of 30 case of implant failure in P.F.N group and revision surgery was required for it.The usual 'Z' pattern of implant failure was the reason.
In the D.H.S group there were 2 of 30 cases of implant failure one was due to screw cut out and other was due to plate breakage.In both the cases revision surgery was required (Table 2).

Greater Trochanter Splintering
The greater trochanter splintering was seen in 2 (6.67%) patients but it did not cause any complication later and healed well.Greater Trochanter was either fixed with Ethibond suture.

Harris Hip Score
In the D.H.S group the 1 month hip score (mean = 24.5)

Discussion
The development of the dynamic hip screw in the 1960's saw a revolution in the management of unstable fractures.
The device allowed compression of the fracture site without complications of screw cut-out and implant breakage associated with a nail plate.However, the extensive surgical dissection, blood loss and surgical time required for this procedure often made it a contraindication in the elderly with co-morbidities.The implant also failed to give good results in extremely unstable and the reverse oblique fracture.In the early 90s intramedullary devices were developed for fixation of Intertrochanteric fractures.These devices had numerous biomechanical and biological advantages over the conventional dynamic hip screw [4][5][6].Long term studies, however, revealed that the use of these devices was associated with higher intra operative and late complication often requiring revision surgery.This has led to modifications in the device and technique of the intramedullary devices.
In our study we found:  Less operative time in PFN group  Less operative blood loss in PFN group  Early return to daily activities. Less complication in PFN group like less infection, less sliding, less limb length discrepancy compared to DHS group.The plate and screw device will weaken the bone mechanically.The common causes of fixation failure are instability of the fractures, osteoporosis, and the lack of anatomical reduction, failure of fixation device and incorrect placement of the screw.
We found the proximal femoral nail to be more useful in unstable and reverse oblique patterns.
Hence PFN is much superior to DHS in management of fracture intertrochanteric femur.