Angular Malalignment in Subtrochanteric and Proximal Shaft Femur Fractures after Intramedullary

Nailing using SIGN Nails

Rolando Junior L. Torres, MD Jeremiah R. Morales, MD, FPOA

Subtrochanteric Femur fracture

from below the level of the lesser trochanter to a level 5cm distal to it

5 cm

Proximal Shaft Femur fracture

femoral diaphysis from 5cm distal to the

lesser trochanter up to 5cm proximal to the adductor tubercle

diaphyseal region is then divided into 3 equal parts

first 3rd or proximal division is known as the proximal shaft

Angular malalignment more than 5 degrees of angular deformity in the sagittal or coronal planes

• Varus • Valgus • Procurvatum • Recurvatum

Ricci, WM et al. Angular Malalignment After Intramedullary Nailing of Femoral Shaft Fractures. Journal of Orthopaedic Trauma. 2001 Vol. 15, No. 2, pp. 90–95

STABLE UNSTABLE

Subtrochanteric & Proximal Femoral Shaft Fractures

Functionally distinct from intertrochanteric and femoral shaft fractures

Technically challenging to manage

Has distinct complications

Technically challenging… Iliopsoas -flexion of the proximal fragment

Gluteal and short external rotator muscles – abduction & external rotation of the hip

Adductor muscles shorten & medialize the distal femur

Subtrochanteric & Proximal Femoral Shaft Fractures

VARUS malalignment Most noted

complication >5 degrees angulation

in coronal/sagittal planes

Ostrum, R.F. et A Critical Analysis of the Eccentric Starting Point for Trochanteric Intramedullary Femoral Nailing. Journal of Orthopedic Trauma. November/December 2005

Ricci, WM et al. Angular Malalignment After Intramedullary Nailing of Femoral Shaft Fractures. Journal of Orthopaedic Trauma. 2001 Vol. 15, No. 2, pp. 90–95

incidence of malalignment was 9 % for the entire group of patients (proximal, middle and distal femur fractures)

30 percent when the fracture was of the proximal portion of the femur

Clinical Consequences of Varus Malalignment

1. Decrease in HIP ABDUCTOR MUSCLE EFFICIENCY

pain

limp

Weakness

Papp, S., Gofton, W., Liew, A.S.L. (2012). Subtrochanteric Fractures. In Bhandari, M. Evidence-Based Orthopedics (pp. 499-502). West Sussex, UK: Wiley-Blackwell

Clinical Consequences of Varus Malalignment

2. FIXATION FAILURE rate @ 26% and NON-UNION

Due to increase in effective lever arm on the fixation

Increase amount of force around the hip joint

Treatment Recommendation

Fracture patterns distal to the lesser trochanter:

• Antegrade, Reamed, Statically locked, Intramedullary nail

• Lee, M.A. et al Fractures of the Proximal Femur. Schimdt,

A.H. and Teague, D.C., editors. Orthopedic Knowledge Update 4th ed: Trauma. Illinois: American Academy of Orthopedic Surgeons. 2010. p. 422-425.

• Nork, SE, et al., Subtrochanteric Fractures of the Femur.

Browner, BD., Levine, AM., Jupiter, JB., Trafton, PG., Krettek, C. Editors. Skeletal Trauma 4th ed. Philadelphia, PA: Elsevier. 2009. Vol. 2 Ch. 51 p.1977-2031.

Static Interlocking Intramedullary Nails

Price Range: $ 300 – 3,500 (P 13,500 – P157,500)

Surgical Implant Generation Network (SIGN) Nails

• Intramedullary implants for:

• Femur • Tibia • Humerus

• Solid nail • No arc of radius • 9 degrees proximal

bend

SIGN SURGICAL TREATMENT PROTOCOL

Open Reduction

Secure Reduction prior to reaming and nail insertion

Using appropriate nail size

Trochanteric entry point

Through 14 years of using SIGN Nails

Piriformis Fossa –Traditional Entry Point

Greater Trochanter–SIGN Entry Point

2-3 mm medial to tip

2-3 mm lateral to tip

(CENTER OF EXCELLENCE)

Through 12 years of using SIGN Nails

Research Questions

What is the incidence of angular malalignment after intramedullary nailing of subtrochanteric and proximal shaft femoral fractures?

Which fracture site will result to high incidence of angular malalignment? Subtrochanteric or Proximal Shaft?

Research Questions

To what degree of fracture comminution will result to high incidence of angular malalignment?

What are the associated complications of intramedullary nailing in subtrochanteric and proximal shaft femoral fractures?

Significance of the Study

investigating the incidence of angular malalignment in these fractures:

would give a statistics of the cases involved

provide inputs for review of our current SIGN surgical treatment protocol

lead to a line of researches in refining surgical techniques and investigating clinical outcomes for these complicated and challenging ur fractures

Objective of the Study

To determine the incidence of angular malalignment in subtrochanteric and proximal shaft femoral fractures treated with SIGN intramedullary nails

Specific objectives

1. Incidence of angular malalignment in: Subtrochanteric femoral fractures

Proximal shaft femoral fractures

2. Which among the proximal femoral fracture sites has the highest risk of angular malalignment.

3. Risk of angular malalignment according to the degree of fracture comminution.

4. Associated complications in intramedullary fixation of subtrochanteric and proximal shaft femoral fractures.

METHODOLOGY

Research Design retrospective cohort study design

Setting chart and radiographs reviews of patients admitted

between January 1 2003 to December 31, 2012

Participants (Inclusion & Exclusion Criteria)

INCLUSION

Subtrochanteric and Proximal Femur Shaft fractures treated with SIGN Nails

EXCLUSION

Patients treated with plates and intramedullary nails other than SIGN nails

pathologic fractures

subtrochanteric fractures with extension to:

greater trochanter

lesser trochanter

piriformis fossa

73 patients were included in the study

Sampling Procedures

Sample size - computed using the software Samp size

Data Gathering

Independent Variables location of fracture degree of comminution

according to Winquist classification

Associated complications

Dependent Variable

ANGULAR MALALIGNMENT

Varus

Valgus

Procurvatum

Recurvatum

Data Handling and Analysis

1. Descriptive Analysis

utilized frequency for qualitative variables

2. Statistical Analysis

Chi-square analysis

Epi Info version 3.5.4.

level of significance is set at 0.05

Results & Discussion

Table 1. Characteristics of Patients with Subtrochanteric and Proximal Femoral shaft Fractures from January 1, 2003

to Dec 31, 2012 Fracture Location

Characteristics Subtrochanter (n=50) Proximal Shaft Femur (n=23) p-value

Sex freq (%)

Male 44 (88) 21 (91) 0.7372

Female 6 (12) 2 (9)

Age (∑x ± sd ) 33 ± 16 26 ± 10 0.001

Mechanism of Injury freq (%)

Vehicular Crash 23 (46) 16 (69) 0.221

Fall 13 (25) 3 (14)

Gunshot Injury 9 (18) 1 (4)

Others 5 (10) 3 (14)

Comminution freq (%)

Winquist 0 16 (32) 13 (56)

0.41

Winquist I 11 (22) 3 (13)

Winquist II 6 (12) 3 (13)

Winquist III 5 (10) 2 (9)

Winquist IV 12 (24) 2 (9)

attributed to the following facts applicable in our setting

males lead a more active life than females

males are more inclined to risk taking behavior

most males are motorcycle drivers by occupation

most males have motorcycles as means of transportation

Morales, J., The Profiles of Patients Involved in Motorcycle Accidents Admitted at the Department of Orthopedics, Davao Medical Center from January 2004 to December 2005. Retrieved from Department of Orthopedics, Southern Philippines Medical Center Archive

Table 1. Characteristics of Patients with Subtrochanteric and Proximal Femoral shaft Fractures from January 1, 2003

to Dec 31, 2012 Fracture Location

Characteristics Subtrochanter (n=50) Proximal Shaft Femur (n=23) p-value

Sex freq (%)

Male 44 (88) 21 (91) 0.7372

Female 6 (12) 2 (9)

Age (∑x ± sd ) 33 ± 16 26 ± 10 0.001

Mechanism of Injury freq (%)

Vehicular Crash 23 (46) 16 (69) 0.221

Fall 13 (25) 3 (14)

Gunshot Injury 9 (18) 1 (4)

Others 5 (10) 3 (14)

Comminution freq (%)

Winquist 0 16 (32) 13 (56)

0.41

Winquist I 11 (22) 3 (13)

Winquist II 6 (12) 3 (13)

Winquist III 5 (10) 2 (9)

Winquist IV 12 (24) 2 (9)

Table 2. Comparison of the rate of angular malalignment between subtrochanteric and proximal shaft femoral

fractures

OUTCOME Subtrochanteric Proximal Shaft p-value

Femur (n-50) Femur (n=23)

Angular 22 (46) 2 (9) 0.002

Malalignment freq (%)

Varus freq (%) 12 (24) 1 (4) 0.036

Valgus freq (%) 2 (4) 0 0.466

Procurvatum freq (%) 5 (10) 0 0.141

Recurvatum freq (%) 2 (4) 1 (4) 0.685

Varus & Procurvatum freq (%) 1 (2) 0 0.685

CURRENT STUDY

46% incidence of angular malalignment in subtrochanter

VARUS angulation most common deformity

RELATED LITERATURES

incidence of malalignment was 9 % for the entire group of patients (proximal, middle and distal femur fractures)

30 percent when the fracture was of the proximal third of the femoral shaft

Ricci et al. JOT 2001

37% post operative angular malalignment in subtrochanteric fractures

Nork, SE , Skeletal Trauma 4th ed 2009

Papp, S et al. Evidence-Based Orthopedics 2012

Factors leading to malalignment in subtrochanteric fractures

1. Deforming muscular forces

Makes intra-op reduction difficult

good reduction key to avoiding malreduction – greatly achieved through open approach

2. More voluminous canal in proximal femur than in diaphysis

Lessens contact of bone and IM nail

Opposed by Ricci et al JOT 2001 NO CORRELATION between angular deformity and nail

diameter-canal contact

Table 3. Comparison of the rate of angular malalignment by degree of comminution

Stable Fractures Unstable Fractures p-value

(Winquist 0-II) (Winqust III-IV)

n=52 n=21

Angular Malalignment freq (%)

16 (30) 8 (38) 0.367

NOT SIGNIFICANT

Table 3. Comparison of the rate of angular malalignment by degree of comminution

Stable Fractures Unstable Fractures p-value

(Winquist 0-II) (Winqust III-IV)

n=52 n=21

Angular Malalignment types

Varus 6 (12) 7 (33) 0.034

Valgus 2 (4) 0 0.504

Procurvatum 5 (10) 0 0.173

Recurvatum 2 (4) 1 (5) 0.645

Varus & Procurvatum 1 (2) 0 0.712

Further analysis revealed

Odds Ratio of having varus malalignment whether the fracture pattern is STABLE or UNSTABLE

>1 (1.05-13.80)

Similar result

Ricci et al Journal of Trauma 2001

High incidence of malalignment in proximal femur fractures regardless of the degree of comminution

Other factors must be sought as a possible cause of malalignment Entry point issue???

Adequate selection of nail entry point Has significant effect on

fracture alignment aside from deforming forces

Noted angular deformity in IM nails with more proximal bend

Significant 6-8 degrees of

malalignment when Greater trochanteric tip entry point used

Ostrum, R.F., Marcantonio, A., DO, Marburger,R. A Critical Analysis of the Eccentric Starting Point for Trochanteric Intramedullary Femoral Nailing. Journal of Orthopedic Trauma. November/December 2005. Vol 19., No. 10

Piriformis Fossa –Traditional Entry Point

Greater Trochanter–SIGN Entry Point

2-3 mm medial to tip

2-3 mm lateral to tip

Table 4. Comparison between associated complications in intramedullary fixation of subtrochanteric

and proximal shaft femoral fractures

Complications freq (%) Subtrochanteric Proximal Shaft p-value

Femur (n=50) Femur (n=23)

Iatrogenic Medial 4 (8) 0 (0) 0.013

cortex comminution

Iatrogenic Lateral 0 1 (4) 0.125

cortex comminution

Femoral Neck Fractures 0 0 …

Gapping of lateral cortex 3 (6) 0 0.248

Others 0 0 ..

Greater Trochanteric Entry Point ‘Too lateral’ Reaming becomes eccentric Nail insertion goes toward the medial cortex

causing comminution

Streubel, P.N., Wong, A.H.W., Ricci, W.M., Garner, M.J. Is There A Standard Trochanteric Entry Site for Nailing of Subtrochanteric Femur Fractures? Journal of Orthopedic Trauma. April 2011. Vol. 25, No. 4

CONCLUSIONS

CONCLUSIONS

1. Incidence of angular malalignment: 46% in subtrochanteric femoral fractures 9% in proximal femoral shaft fractures

2. Varus deformity: 24% incidence rate Subtrochanteric location is a significant

factor for angular malalignment

CONCLUSIONS

3. The relationship between the degree of fracture comminution and angular malalignment is not significant. However, further analysis showed that in

unstable fractures there is a risk for varus malalignment with and odds ratio of >1.

4. Subtrochanteric location also posed a risk for

iatrogenic medial comminution

SIGN NAIL CONFIGURATION and ENTRY POINT may impose significant risk for angular malalignment especially for subtrochanteric fractures

THANK YOU!