Hip fractures are a growing global health concern, with their incidence projected to double in the United States alone, reaching nearly 500,000 cases annually within the next two decades [1]. This increase is primarily attributed to rising life expectancy and sustained physical activity levels among the elderly population. It is estimated that one in three women and approximately 8% of men will sustain a hip fracture in their lifetime. In older adults, hip fractures account for nearly 50% of all fractures [1].

The Asian subcontinent is expected to contribute over 50% of the global burden of trochanteric fractures by the year 2050 [2]. This growing burden presents significant challenges not only to individual patients but also to healthcare systems due to the associated high morbidity, mortality, and economic costs [3]. Global projections suggest that the number of hip fractures will rise to 2.6 million by 2025 and escalate further to 6.25 million by 2050. Alarmingly, mortality rates following hip fractures range from 12% to 41% within the first six months [3].

Early surgical intervention is considered the standard of care for intertrochanteric fractures, especially in elderly patients [4]. Combined intertrochanteric and subtrochanteric fractures account for 10–34% of all hip fractures. The biomechanical forces acting on the proximal femur—particularly the strong compressive and tensile pull of surrounding muscles—lead to displacement of fracture fragments, contributing to instability. Consequently, conservative treatment is generally not recommended for unstable intertrochanteric (IT) fractures [5].

Although dynamic hip screw (DHS) fixation has been widely used, numerous studies have reported higher complication rates in unstable IT fractures treated with this method. Despite advancements, there remains no universally accepted guideline or ideal implant for managing these challenging injuries. Given the reported biomechanical advantages of the proximal femoral nailing (PFN) system, we sought to investigate its functional outcomes in both young and elderly patients. To address this research question, we conducted a prospective analytical observational study involving 121 cases of unstable intertrochanteric fractures treated with short and long PFN at KIMS General Hospital, Amalapuram, Andhra Pradesh, India, between February 2022 and August 2024

Aim: To study Functional outcome of Intertrochanteric fractures (Unstable) treated by Proximal Femoral Nailing System (PFN) in young adults and elderly patients.

Objectives:

• To find out common age group, gender affected & most common cause of injury,
• To know the spectrum of fracture patterns of IT fractures,
• To know the appropriate time of union of fracture & effect of PFN on union rate of IT fractures
• To know about Complications and their rate in the fractures operated with Proximal Femoral Nail system (The Z effect and Reverse Z effect etc.)
• To know the overall functional status(excellent/Good) of the patient at the end of 6 months.

Study Design and Setting

This was a prospective analytical observational study conducted at KIMS General Hospital, Amalapuram, Andhra Pradesh, from February 2022 to August 2024. The study included patients from predominantly rural populations presenting with unstable intertrochanteric fractures.

Ethical Approval and Consent

Institutional Ethics Committee (IEC) approval was obtained prior to initiating the study. Written informed consent was taken from all participants after explaining the purpose and nature of the study.

Sample Size and Selection Criteria

A total of 121 patients were included using random sampling.

Inclusion Criteria

• Age ≥18 years
• Pre-injury independent ambulation (with or without support)
• Radiologically confirmed unstable intertrochanteric fractures (AO/ASIF Type 31A2 and 31A3)
• Willingness to undergo regular follow-up and adhere to the physiotherapy protocol

Exclusion Criteria

• Pediatric patients
• Open or multiple fractures
• Stable intertrochanteric fractures (AO Type 31A1)
• Undisplaced fractures
• Pathological fractures or neuromuscular disorders
• Patients with neurovascular deficits
• Debilitated or bedridden elderly unable to ambulate
• Patients unwilling for follow-up or physiotherapy

Data Collection and Preoperative Evaluation

Demographic data including age, gender, side and mode of injury, and days since injury were recorded. Radiological evaluation included pelvis with bilateral hips (AP view) and full-length lateral views with traction and internal rotation. AO/ASIF classification was used to categorize fractures.

Fracture criteria for instability included:

• Lateral wall fractures (Type I, II, III)
• Large posteromedial fragment
• Calcar comminution
• Reverse obliquity
• Medial to lateral cortex extension
• Subtrochanteric extension
• Patients were stabilized using skin traction on a Böhler-Braun splint prior to surgery.

Surgical Technique

Preoperative Preparation

• Anesthesia fitness assessed
• Fracture reduction attempted with traction, abduction, internal rotation, and adduction
• Temporary fixation using K-wires (2.5 mm)
• Implants used were locally sourced stainless steel 316L PFNs (Varuni Surgical Pvt. Ltd and Nebula Surgical Pvt. Ltd, Kakinada)

Implant Specifications

Short PFN: 180 mm/250 mm; diameters: 9–12 mm

Long PFN: Customized length depending on femoral length

Valgus neck-shaft angle: 135°

Mediolateral angle: 6°

Cervical screw: 8 mm; Derotation screw: 6.5 mm

Distal locking bolts: 4.9 mm

Intraoperative Steps

ü  Supine positioning on fracture table

• 3 cm lateral incision over greater trochanter
• Entry made using cannulated awl into pyriform fossa
• Nail inserted after sequential reaming
• Guide wire placed and confirmed under fluoroscopy
• Lag screw placed inferiorly on AP and posteriorly on lateral views
• Derotation screw inserted 15 mm shorter than lag screw
• Tip Apex Distance (TAD) maintained <25 mm in all cases
• Distal locking: external jig for short PFN; freehand for long PFN
• Lateral wall fractures fixed using tension band wiring when needed
• Surgery duration, blood loss, and radiation exposure recorded

Postoperative Care and Rehabilitation

• Wound inspection on postoperative day 2
• X-ray for fracture reduction and implant positioning
• Physiotherapy initiated on day 2 with passive ROM
• Discharge by day 5 if hemodynamically stable and no signs of infection
• Sutures removed at 2 weeks

Rehabilitation Protocol:

Active-assisted physiotherapy in OPD and home-based

Partial weight-bearing initiated after 8 weeks

Full weight-bearing allowed after radiological evidence of callus (usually post 12 weeks)

Strengthening exercises for hip abductors, adductors, extensors, quadriceps, and gait training conducted regularly

Follow-Up and Functional Assessment

Patients were followed up at 4, 8, 12, 16, 20, and 24 weeks. Functional outcome was assessed at 6 months using the Modified Harris Hip Score (HHS), which consists of 100 points categorized as:

Pain (44), Limp (11), Distance walked (11), Support (11), Sitting (5), Public transport (1), Stair climbing (4), Shoe/sock wear (4), Deformity (4), Range of motion (5)

HHS Grading:Excellent: 91–100, Good: 81–90, Fair: 71–80, Poor: <70

Statistical Analysis

The collected data was analyzed using the latest version of SPSS software. Appropriate statistical tests were applied based on the nature and distribution of the data. The Chi-square test (χ²) was used to assess associations between categorical variables. The student’s t-test and Z-test were employed to compare means of continuous variables where data followed a normal distribution. For non-parametric data, the Wilcoxon Signed-Rank Test and Mann-Whitney U Test were utilized to evaluate paired and unpaired group differences, respectively. A p-value of less than 0.05 was considered statistically significant in all analyses.

A detailed assessment was carried out on 121 patients with unstable intertrochanteric fractures. Of these, 68 were male and 53 were female. The age range of participants was from 24 to 92 years, with a mean age of 67.92 years. The right side was affected in 69 patients, while 62 had left-sided injuries. The majority of fractures (n=104) were caused by self-fall at home, while 17 cases were due to road traffic accidents.

Based on AO/ASIF classification, 87 patients had A2 type fractures, and 34 had A3 type fractures. All A2 fractures were treated using short PFN (n=88), while all A3 fractures were treated using long PFN (n=33). A 135-degree valgus angle nail was used in all cases.

Fracture union was observed in 104 patients between 10 to 12 weeks, while 17 patients achieved union between 16 to 20 weeks. The average surgical time was 60 to 70 minutes for short PFN and 80 to 90 minutes for long PFN. Average intraoperative blood loss was 250–260 mL for short PFN and 280–290 mL for long PFN. Radiation exposure time was around 10 minutes for short PFN and 15–20 minutes longer for long PFN.

Postoperative complications included:

Superficial infection in 3 patients (successfully managed with culture-guided IV antibiotics)

Deep infection in 1 patient (treated with implant removal and skin traction)

Superior screw cut-out in 1 patient (managed with implant removal and hemiarthroplasty)

Z-effect in 4 patients (3 underwent implant removal and hemiarthroplasty, while 1 refused surgery and developed malunion)

Pulmonary embolism in 1 patient

Nonunion in 1 patient

Malunion in 1 patient

At six months postoperatively, functional outcomes based on the Modified Harris Hip Score were:

Excellent in 74 patients (61.15%)

Good in 35 patients (28.92%)

Satisfactory in 6 patients (4.9%)

Poor in 6 patients (4.9%)

The reoperation rate was 4.13% (5 patients) and the overall complication rate was 9.91% (12 patients).

 Pre op X ray A2 fracture                 Pre op X ray A3 fracture                     Patient position on fracture table

Intra op incision and temporary fixation with 2 K wires & Intra Op C -ARM images PFN insertion

Post OP wound closure           X ray post op Short & Long PFN                    Implant failure ‘Z’ effect

Healed surgical scar post op        Healed Fracture (short PFN)                               Healed fracture (long PFN

Pertrochanteric fractures constitute nearly 50% of all proximal femoral fractures [6]. While stable fractures tend to yield good outcomes with conventional fixation, unstable intertrochanteric fractures remain challenging due to a higher risk of fracture collapse, malunion, and implant-related complications such as lag screw cut-out [6]. However, nonunion remains rare owing to the rich blood supply of the extracapsular region of the proximal femur [6].

Effective management of these fractures requires meticulous attention to implant selection, precise anatomical reduction, surgical technique, and structured postoperative rehabilitation to restore pre-injury function [6]. Among the major contributing factors to hip fractures, osteoporosis-related reduction in bone mineral density (BMD) remains a primary predictor, particularly in postmenopausal women [6]. Additional risk factors include prior osteoporotic fractures, maternal hip fractures, smoking, and low BMI. In elderly individuals, impaired vision, poor balance, cardiovascular conditions, polypharmacy, inadequate lighting, and household hazards further increase fall risk.

In our study, we observed a male predominance (68 males vs. 53 females), which contrasts with previous literature that reports a higher incidence among females [1,7]. This discrepancy may be attributed to a significant number of road traffic accidents (17 cases) involving younger male patients in rural settings, where two-wheeler usage is common. Conversely, self-fall at home accounted for 104 cases, primarily involving elderly women, in line with established trends.

Fracture classification plays a pivotal role in determining prognosis. We employed the AO/OTA system, categorizing 87 cases as Type A2 and 34 as Type A3. The instability was defined by factors such as lateral wall involvement, posteromedial comminution, calcar loss, reverse obliquity, and subtrochanteric extension [6]. Precise radiological evaluation using full-length femur radiographs helped assess deformity, shaft bowing, and proper nail selection.

In unstable patterns, particularly reverse oblique and subtrochanteric fractures, long PFN offers superior biomechanical stability. Short PFN was used in A2 fractures and long PFN in all A3 fractures, with a 135° valgus neck-shaft angle and TAD maintained under 25 mm, which has been shown to reduce screw cut-out risk [10,11].

Our surgical outcomes showed that mean union time was 10–12 weeks, with delayed union up to 20 weeks in elderly patients (>80 years). Functional results assessed via Modified Harris Hip Score (MHHS) were excellent in 61.15%, good in 28.92%, satisfactory in 4.9%, and poor in 4.9%. These results are consistent with those reported by Vivian et al. [15] and superior to outcomes of DHS fixation.

Complication rates in our study were low (9.91%), including superficial infection (3 cases), deep infection (1), Z-effect (4), pulmonary embolism (1), screw cut-out (1), nonunion (1), and malunion (1). Notably, Z-effect was observed in only 3.3% (4/121) of cases, lower than that reported by Werner-Tutschku et al. (7/70 cases) [20–24], likely due to superior surgical technique and careful screw positioning.

Our findings align with those of Baumgaertner et al., who advocated for optimal screw placement and TAD <25 mm to prevent failure [10,11]. The PFN system outperformed DHS in surgical duration, blood loss, and functional outcomes [1,15,16], and was comparable or superior to other implants like DCS, PFLCP, and Gamma nails in biomechanical strength and complication profile [2,3,4,6].

While DHS remains effective for stable fractures, its use in unstable patterns, especially A2 and A3, is associated with higher failure rates, varus collapse, and cut-outs [9,16]. Comparatively, PFN allows minimally invasive fixation, maintains better limb length, and ensures early weight-bearing and mobility [15,17].

In comparing short vs. long PFN, although short nails reduce surgical time and blood loss, there was no significant difference in union rate, reoperation, or functional outcomes [1]. Long PFN, however, provides greater stability in reverse oblique and osteoporotic cases by reducing stress on the femoral neck and lateral wall [6].

Compared to hemiarthroplasty, PFN offers shorter operative time, reduced mortality, lower blood loss, fewer implant-related complications, and better preservation of natural bone, though cemented hemiarthroplasty remains an option in severe osteoporosis or salvage procedures [18,19].

Regarding the implant itself, PFNA (Proximal Femoral Nail Antirotation) with a single helical blade may reduce operative time and bone trauma [3], but it is more expensive. In our study, locally manufactured stainless steel PFNs were used successfully to minimize financial burden, and no additional complications related to implant quality were observed.

Other notable findings include:

Physiotherapy began on postoperative day 2, with individualized 1:1 sessions and muscle strengthening exercises, which significantly improved functional recovery. Mariana Barquet et al. emphasized the importance of focused rehabilitation in elderly patients for improved outcomes [12,13].

Tip-apex distance, lag screw positioning (inferior on AP and posterior on lateral view), and lateral wall support were meticulously addressed to prevent implant failure [9,14].

Our complication rate (9.91%) was lower than those reported in several series, including intraoperative PFN complication rates (23.4%) and screw cut-outs (5.7%) in some studies. This success is attributed to precise surgical execution, careful fracture planning, and strict postoperative protocols.

The treatment of unstable intertrochanteric fractures remains a surgical challenge due to the inherently higher risk of complications. However, the Proximal Femoral Nailing (PFN) system offers distinct biomechanical and clinical advantages that make it a reliable and effective choice. As an intramedullary device, PFN is biomechanically stronger and minimally invasive, thereby preserving the biological environment at the fracture site. The combination of a compressive lag screw and a derotation screw provides excellent rotational and axial stability to the femoral head and shaft. The intramedullary location of the nail acts as a buttress for the lateral wall, preventing medialization of the shaft and enhancing construct stability. Additionally, the dynamic distal locking mechanism permits controlled axial collapse, facilitating early fracture union while reducing the need for postoperative blood transfusions.

The availability of long nail options provides added protection in severely osteoporotic or Type 3 fractures, covering the entire femoral shaft and minimizing the risk of subsequent fractures. Compared to other fixation methods, PFN is associated with lower postoperative complication and reoperation rates, is easier to use surgically, and serves as a more favorable option than hemiarthroplasty in many cases.

However, despite these advantages, PFN is not without limitations. Long-term follow-up studies and high-quality meta-analyses are necessary to assess the implant’s longevity and to develop strategies for minimizing complications such as Z-effect, reverse Z-effect, and lag screw cut-out. Future research should aim to optimize implant design and surgical techniques to further enhance the safety and effectiveness of PFN in managing unstable intertrochanteric fractures.

Conflict of Interest: None

Funding: No funds received for this Research

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