Silver jubilee purple

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  • Review of lietrature shows problems of all designs – cut out
  • Additional instability of lateral wall – unwanted collapse patterns and high rate of reoperation and patients disstaisfaction
  • Stability of fracture implant construct should last till bone to bone contact and expectations from design are it should allow augmentation if required,it should prevent futher injury to fracture zone particularly lateral cortex and abductor mechanism, should maintain reduction, must provide continous stability with controlled guided limited collapse and should matchn the anatomic profile of femur and technically simple to give reproducble results reducinfg complications and reoperationrates
  • Mineral density below o.6 g / cm by dexa is predictor for poor fixation – in such case of unstable fracture augmebtation or primary repalcement is the alternative
  • Reverse oblique and transverse fractures are unstable and tendency for medial displacement- intramedullary impalnts are proved better in this situation
  • Imtrameduallry impalnts are biomechanically stronger than extramedullary implants
  • area of Place of elements of fixation in neck and head has direct relation with prediction of failure – if u want to put one – it is better to have it at inferior portion and in centre in lateral view I f secon is to be inserted – better in middle and centre – whwre cut out chance are less but antrior and superior placement shouild be avoided
  • Tip apex distance has same importance as in extramedullary implant
  • We studied different mesurements , angles and dimeters of proximal femur from ct scan data
  • Glidiing nail with one neck element having I beam configuration
  • Material properties to different bone parts , and fracture zone and implant was assigned
  • OBSERVATIONS MADE foccusing these 4 technical problem areas and technical changes were done hoping solution
  • For rotational varus stability of proximal fragment shape of element in neck and number of elements in neck are important varibles and we found that
  • Other than non thread designre more rotationally stable – had compaction of bone with less bone removal.
  • same way Two are better than one
  • Collapse is very complex issue involving many
  • Variables , where lateral cortex instability is was observed one of the crucial factor and un expected collapse –migaation of neck elements is a sign of post fixation instability
  • Collapse is very complex issue involving many
  • Variables , where lateral cortex instability is was observed one of the crucial factor and un expected collapse –migaation of neck elements is a sign of post fixation instability
  • Aim and principle of this new design is to preserve lateral cortex – if precarious , if broken support with slit buttress plate inserted minimally invasive and also provide smooth uniform contionuous contact surface for gliding for controlled collapse – this is novel design idea
  • Sex,age , type of frcture , operated on fracture table and fixed with nailplate assembly and intraoperative findings noted
  • On force adding plate – no varus –cyclic loading - controlled limited collapse.
  • Follow ups
  • Union and function
  • Folllow up union and function
  • When entry of neck elemnts at lateral cortex is intact and u are no damaging with large drilling.
  • There are dificulties in rightly placing implants with western copied implants and jigs and that leads to failure
  • It has been very well reported in literature
  • On modeling we observed difficult distal locking with straight nail as noted in literature
  • surgeon should choose design which fulfils biomechanical principles - expectations as above .
  • Thank u
  • Silver jubilee purple

    1. 1. Desired Design Of Implant For Unstable Extra Capsular Proximal Femur Fractures Silver Jubilee Oration IOACON 2012 Dr. Navin Thakkar Ahmedabad
    2. 2. Problem .. .. …Day in and day out….. Unstable Extra capsular Elderly + Osteoporosis Early mobilization Assisted full wt. bearing Higher biomechanical Properties Implant system Rene Marti & Dunki Jacobs , Ph. Procter 1992
    3. 3. Problem….Day in….Day out. Which Design to Choose ? ….. Why Failure ? Instability Even After Ideal Placement of Implant Subset -Unstable Extra capsular -A2,A3 Cut out 3-27%-review of literature1,2,3 Lateral Wall BrokenUnclassified Further Violation – Large Hip Screw Drilling No Lateral Platform – No Smooth Sliding Surface
    4. 4. Problem….Day in….Day out. Which Design to Choose ?….. Why Failure ? Instability Even After Ideal Placement of Implant Subset -Unstable Extra capsular -A2,A3 Medial migration 6-11%-review of literature3,4,5 Lateral Wall BrokenUnclassified Further Violation – Large Hip Screw Drilling No Lateral Platform – No Smooth Sliding Surface
    5. 5. Problem….Day in….Day out. Which Design to Choose ?….. Why Failure ? Instability Even After Ideal Placement of Implant Subset -Unstable Extra capsular -A2,A3 Lateral migration 4-22%-review of literature3,4,5 Lateral Wall BrokenUnclassified Further Violation – Large Hip Screw Drilling No Lateral Platform – No Smooth Sliding Surface
    6. 6. Change in Biomechanical Understanding Over the past 50 years the Extra capsular Proximal Femur fractures have not changed much excepting that there are many more of them today, however understanding of biomechanics has advanced great deal over this period Tronzo – (1974)
    7. 7. Forces After Fixation Direction (Planes) + Large + Dynamic + Cyclic Even After Reduction & Fixation
    8. 8. Forces In Routine Activity Walking with support Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients. Heller MO, Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN.
    9. 9. Forces In Routine Activity Stair Climbing with support Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients. Heller MO, Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN.
    10. 10. Forces In Routine Activity Stumbling Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients. Heller MO, Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN.
    11. 11. Forces In Routine Activity Flexion – Extension of Hip Very High Rotational, Varus – Bending and Shear Force at Head and Neck Junction and Screw Interface
    12. 12. Review of Literature Biomechanical Principles - Observation 2 Ante version Of Femur Neck and Loading Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9. Influence of femoral anteversion on proximal femoral loading: measurement and simulation in four patients. Heller MO, Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN.
    13. 13. Expectations from desired design of my implant Factors - Fracture Implant Construct Stability 1. Quality of bone : Allow Augmentation 2. Fragment Geometry- Avoid Injury to Partly modifiable Not in Control lateral wall – trochanter – abductor - biology 3. Reduction Avoid displacement on entry –maintain reduction 4. Under Control Depends on Fracture Choice of Implant Rotational–varus – shear -lateral wall stability Controlled guided limited collapse Under Control 5. Implant Placement and profile allow ideal placement –match profile Under Control of proximal femur – technically reproducible Depends on design Chosen –average surgeon –cost effective
    14. 14. Biomechanical Principles Observation 9 Quality of Bone and Augmentation neck and head In an unstable fracture model (type A 2.3 of the AO classification), the implants DHS with TSP, PFN and TGN showed a stable long-term loadbearing capacity at a bone mineral density of >0.6 g/cm3. by DEXA An appropriate augmentation of the trabecular bone of the femoral head is required for sucessful osteosynthesis when critical value of sufficient bone density is < 0.6 g/cm3. by DEXA . Another alternative could be the primary implantation of an endoprosthesis in the treatment of these patients. Critical value of sufficient bone density is < 0.6 g/cm3. by DEXA "Cutting out" in pertrochanteric fractures--problem of osteoporosis?] Unfallchirurg. 2007 May;110(5):425-32. Bonnaire F, Weber A, Bösl O, Eckhardt C, Schwieger K, Linke B.
    15. 15. Biomechanical Principles Observations 10 Fracture Geometry and Forces Reverse Oblique and Transverse Medial Displacement Force is very high Intra medullary implants are better than Extra medullary implant Treatment of Reverse Oblique and Transverse Intertrochanteric Fractureswith Use of an Intramedullary nail or a 95° Screw-Plate A PROSPECTIVE, RANDOMIZED STUDY CHRISTOPHE SADOWSKI, MD, ANNE LÜBBEKE, MD, MARC SAUDAN, MD, NICOLAS RIAND, MD, RICHARD STERN, MD, AND PIERRE HOFFMEYER, MD
    16. 16. Biomechanical Principles - Observation 8 Anatomic Reduction V/S Non anatomic Reduction Little Valgus is better Varus must be avoided
    17. 17. Biomechanical Principles Observations 11 Biomechanics studies have demonstrated inferior stiffness and load to failure of extra medullary devices of fixed angle blade plate or hip compression screw construct compared with that of second generation reconstruction nails in a cadaveric model Tencer et al Curtis MT Wilson V Johnson KD
    18. 18. Extramedullary Plate =< Intramedullary Plate (Nail) Reduced lever arm
    19. 19. Less telescoping
    20. 20. Prevents medialisation-Shaft
    21. 21. Biomechanical Principles - Observation 6 Placement of elements of fixation in neck and head The distribution, by zone, of the 198 screws and of the sixteen screws that cut out. The total number of screws in each zone is represented by the numerator, and the number of screws that cut out in each zone is represented by the denominator From: Baumgaertner: J Bone Joint Surg Am, Volume 77-A(7).Jul , 1995.1058-1064
    22. 22. Biomechanical Principles - Observation 7 Tip Apex Distance (TAD) MEDLINE AuthorsShyam Kumar AJ. Parmar V. Bankart J. Williams SC. Harper WM. Authors Full NameShyam Kumar, A J. Parmar, V. Bankart, J. Williams, S C. Harper, W M. InstitutionUniversity Department of Orthopaedics, Glenfield Hospital, Groby Road, Leicester, LE3 9QP, UK. ajshyamkumar@hotmail.co.uk TitleComparison of accuracy of lag screw placement in cephalocondylic nails and sliding hip screw plate fixation for extracapsular fractures of the neck of femur. SourceInternational Orthopaedics. 30(5):320-4, 2006 Oct. AbstractThis study compared the accuracy of lag screw placement between extracapsular femoral fractures fixed with sliding hip screw plate systems and those fixed with cephalocondylic nails. It involved 75 retrospective radiographs of fractures fixed with either a cephalocondylic nail (32) or a sliding hip screw plate system (43). Postoperative anteroposterior and lateral radiographs of the hip were scanned using a digital X-ray scanner and measured using computer software. Measurements were conducted by two independent observers, and the radiographs were calibrated to correct for magnification. Accuracy of lag screw placement was determined by "tip apex distance," described by Baumgaertner et al., and by the ratio method described by Parker. The mean tip apex distance was 24.0 mm in sliding hip screw plate systems and 21.1 mm in cephalocondylic nails. This was found to be statistically significant. Lag screw placement through cephalocondylic nails is more accurate and therefore has less chance of cut-out compared with sliding hip screw plate systems. There was no statistically significant difference using Parker's ratio method because this method quantifies the direction of the screw rather than the depth of penetration. Same importance In Intramedullary Implants as in Extramedullary Implants to have better rotational stability and less fixation failure – cut out , reverse z effect Awareness of Tip-Apex Distance Reduces Failure of Fixation of Trochanteric Fractures of the Hip Baumgaertner, Michael R.; Solberg, Brian D. 79B(6), 1997, 969-971
    23. 23. Disappointments…..Available Designs Limitations / Acceptability ? Instability Malunion size Technical complexity post Implant instability dynamicity “PFN has technical difficulty in correctly placing Collapsibility Compromised anatomical profile two screws femoral neck, particularly since most of our patients were short women with CT Ski gram A. small femoral neck” Herrera et al., International Orthopedics (SICOT 2002), 26:365-369 in
    24. 24. Need……Biomechanical Observations –New Design 1. Indian Bone Dimension - Size discrepancy CT Scan Data of proximal femur - Solid - Mesh Models 2. Computer Instability Models - Biomechanics Computerized Prototypes of Different Implant –Bone Assembly Finite Element Analysis – Observations for Implant –Bone System 3. Technical Changes in New Design Technical / Clinical Problems – Technical Solutions 4. Validation of New Design – Clinical Trial Technically simple-Reproducible-Cost effective
    25. 25. CT Scan Data Proximal Femur - FEA (Finite Element Analysis) 55 year old, Body Weight (BW) 76 kilogram Indian man PASLE study Dr Balushankaran
    26. 26. Computer 3D Bone models Femur- FEA (Finite Element Analysis) Solid Model Mesh Model
    27. 27. Validation and simulation of fractures • Jpeg files of fracture models - good quality , different parts – transparent etc for manipulations and animations
    28. 28. Unstable Fracture Simulation - 3D Bone Models - A (Finite Element Analysis) Unstable Fracture – Lateral Cortex Relatively Intact
    29. 29. Unstable Fracture Simulation - 3D Bone Model B (Finite Element Analysis) Unstable Fracture – Lateral Cortex Broken Badly-unclassified in literature
    30. 30. Computer -implants - part prototypes (Finite Element Analysis) modeling DHS TSP
    31. 31. Computer -implants - part prototypes - FEA (Finite Element Analysis) Gamma Nail (GN) –One screw
    32. 32. Computer -implants - part prototypes - FEA (Finite Element Analysis) PFN –AO – Two Screws (PFN)
    33. 33. Computer -implants - part prototypes - FEA (Finite Element Analysis) PFN Anti rotation ( PFNA) Helical Blade
    34. 34. Computer -implants - part prototypes - FEA (Finite Element Analysis) GLIDING NAIL I Beam
    35. 35. Computer -implants - part prototypes - FEA (Finite Element Analysis) Nail Triflange Hip Pin Buttress Slit Plate (BSP) Indigenous Nail Assembly – Desired Design ( DD) and DD +BSP
    36. 36. Model Model A (a,b,c) and Model B Model B Implant DHS DHS +TSP GN PFN PFNA GLN DD DD +BSP Construct EM * EM IM † IM IM IM IM IM+EM Neck Element Number 1 2 1 2 1 1 2 2 Neck Element Shape screw screw screw screw blade I beam triflange triflange Neck Element Diameter (mm) 12..5 I ‡ 12.5 S§ 6.5 12.5 I 10.5 S 6.5 11.5 13.5 I 6.4 S 6.4 I 6.4 S 6.4 Proximal Diameter of Nail (MM) NA || NA 15.5 17 15.5 17 12.6 12.6 Distal Nail Shape NA NA S** S S S C†† C Material SS ‡‡ SS SS SS SS SS SS Properties *, EM = EXTRAMEDULLARY † = INTRAMEDULLARY , ‡,= INFERIOR §= SUPERIOR , || = NOT APPLICABLE, , ** = STRAIGHT , †† = CURVED , ‡‡ = STAINLESS STEEL SS
    37. 37. Bone Implant Assemblies (Finite Element Analysis)
    38. 38. Material properties - femur and implant -FEA (Finite Element Analysis) Item Elastic constant E(MPa) Head Neck 900 Possion’s Ratio 0.29 620 0.29 Shaft 17000- 14000 0.29 Bone Marrow 100 0.29 Trochanter 260 0.29 Implants S.S. 2× 105 0.30 Fracture Zone 10 0.29
    39. 39. Forces and Coordinate System (Finite Element Analysis) Force in Fx ,Fy , Fz planes – Resultant Vector F at 250 Frontal Plane - Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9 .
    40. 40. Vector F Translation - Walking Vector Translating Symmetrically In Antero-posterior Direction By About 13 Mm ± Relative To The Femoral Head Apex.
    41. 41. Cyclic Loading –Implant –Bone Assemblies (Finite Element Analysis) Flexion – Extension of Hip Cyclic loading from 150% to 300% body weight – till 80,000 cycles or cutout – Number of cycles to cutout– N cutout
    42. 42. Proximal Fragment Rotation PFrotation
    43. 43. Proximal Fragment Varus PFvarus
    44. 44. Pf Varus , Pf rotation • Cut out animation , FNE medail and lateral df medialisation in dhs more the load more cycles - dhs pfn -
    45. 45. Migration of neck element in DHS –Model A
    46. 46. Migration PFvarus in DHS , DHS+TSP,GN,PFN, PFNA ,GLN–Model A
    47. 47. Migration PFrotation in DHS , DHS+TSP,GN,PFN, PFNA ,GLN–Model A
    48. 48. Load Specimen Number of Cycles for cut out Ncutout for Implant – Model A DHS DHS+TSP GN PFN PFNA GLN a 59300 80000 b 19240 38850 33540 38966 48320 76350 c 15180 29250 23434 35220 41900 61790 18623 36409 31948 39129 49840 72713 7640 14980 12910 16350 32860 62800 b 6200 12320 10325 15760 30320 56360 c 5280 11160 11430 17850 22970 51400 6373 12820 11555 16653 28717 56853 a 6750 13240 10450 15320 28350 48430 b 4690 9350 8120 11459 26200 43900 c 2900 5790 9230 12780 18340 37450 Average 4780 9460 9267 13186 24297 43260 a 2.23kN (300%BW) 43200 Average 1.86kN ( 250% BW) 38870 a 1.49kN (200% BW) 41128 Average 1.1kN (150% BW) 21450 4815 8760 6230 10230 24120 34150 b 3100 6190 5320 8450 21580 29570 c 2240 4210 5840 9220 15350 26790 Average 3385 6387 5797 9300 20350 30170
    49. 49. Technical -Clinical Problems 1. Cut Through – Rotational and Varus Stability Hold in proximal fragment – Number of elements and shape of elements 2 .Unwanted Collapse Pattern - Sign of Lateral Cortex Instability , Shear Stress , Poor Hold post fixation instability , Screw Head Abutment 3. Difficulty in Placement – Indian Bone dimensions Proximal femur Shattering , Neck Dimensions Small , Single Plane Jig 4. Profile of Implant mismatch with Proximal Femur Stress concentration at Tip – Pointing Effect
    50. 50. Technical -Clinical Problem 1. Cut Through – Rotational and Varus Stability Variables • • Shape of Element Number of Elements Constants • Quality of Bone • Quality of Reduction • Ideal Placement of Implant
    51. 51. FEA Observations Shape of holding elements in neck Neck Element(NE) -Screw Thread Design Neck Element(NE) -Non Thread Design Non Thread Design - more N cutout cycles than Screw Thread Design .
    52. 52. FEA Observations Number of holding elements in neck Dynamic Hip Screw (DHS) Gamma Nail (GN) Neck Element(NE) -Single Dynamic Hip Screw (DHS) with TSP PFN (AO) Neck Element(NE) –More Than one Neck Element(NE) –More Than one - more N cutout cycles than Single NE .
    53. 53. Technical Change – Clinical Solution 1. Parallel,cannulated, two triflanged pins 40 mm triflanged • Rotational stability • Supports well flat at narrow calcar • Prevents cut thru at superior flat • Better grip due to compaction of cancellous bone Two • Better rotational stability than one • Smaller diameter of 6.4 mm CT SECTION Narrow calcar Parallel & sliding • Desired controlled collapse Better bone contacts Cannulated • Guided insertion for precision
    54. 54. Technical Change – Clinical Solution 2. Multiple hole ,cannulated, triflanged pins Quality of Bone-Osteoporosis Augmentation-Cement
    55. 55. • First novel idea – submission of two elements in neck other than thread design
    56. 56. Technical -Clinical Problem 2 . Unexpected Collapse Pattern 1. Medial Displacement of distal fragment 2. Medial Migration of neck Element 3. Lateral Migration of Neck Element 4. Combination of Above
    57. 57. Technical -Clinical Problem 2 . Unexpected Collapse Pattern Multiple Variables combination factors 1. Poor Hold In Proximal fragment –rotation - varus 2. Poor Hold in distal fragment –shear stress 3. Lateral Cortex Instability – Pre op or Intraoperative 4. Abuting of Head inside lateral cortex 5. Varus changing collapse axis-fixed angle Constants • Quality of Bone • Quality of Reduction • Ideal Placement of Implant Sign of Instability even after fixation ? ?
    58. 58. Lateral Pillar Stability – Lateral Cortex Femur Technical Problem 2 Nothing to support Laterally No stable Platform No Smooth Continuous sliding Barrel to have smooth gliding of hip Pins Further Violation of Lateral cortex stability – Larger Hip screw Drilling Henric Palm et al. Integrity of the lateral femoral wall in intertrochanteric hip fractures An Important Predictor of a Reoperation. JBJS Am. 2007;89:470-475. Gotfried Y . The lateral trochanteric wall: a key element in the reconstruction of unstable pertrochanteric hip fractures. Clincal Orthopedics Related Research . 2004 Aug;(425):82-6.
    59. 59. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Unexpected Collapse Pattern “Z” Pattern Proximal Migration Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31-7. 10.6 % . Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 3/55 cases 6% Tyllianakis M . at al Acta Orthop Belg. 2004 Oct;70(5):444-54 5/45 10.9%
    60. 60. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Unexpected Collapse Pattern “Reverse-Z” Pattern Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 2/55 cases 4% Distal Migration Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31-7. 21.6 %
    61. 61. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Medial Displacement of Distal Fragment - Loss of Reduction
    62. 62. Technical -Clinical Problem 2 . Unexpected Collapse Pattern 1. Medial Displacement of distal fragment 2. Medial Migration of neck Element 3. Lateral Migration of Neck Element 4. Combination of Above
    63. 63. Technical -Clinical Problem 2 . Unexpected Collapse Pattern Multiple Variables combination factors 1. Poor Hold In Proximal fragment –rotation - varus 2. Poor Hold in distal fragment –shear stress 3. Lateral Cortex Instability – Pre op or Intraoperative 4. Abuting of Head inside lateral cortex 5. Varus changing collapse axis-fixed angle Constants • Quality of Bone • Quality of Reduction • Ideal Placement of Implant Sign of Instability even after fixation ? ?
    64. 64. Lateral Pillar Stability – Lateral Cortex Femur Technical Problem 2 Nothing to support Laterally No stable Platform No Smooth Continuous sliding Barrel to have smooth gliding of hip Pins Further Violation of Lateral cortex stability – Larger Hip screw Drilling Henric Palm et al. Integrity of the lateral femoral wall in intertrochanteric hip fractures An Important Predictor of a Reoperation. JBJS Am. 2007;89:470-475. Gotfried Y . The lateral trochanteric wall: a key element in the reconstruction of unstable pertrochanteric hip fractures. Clincal Orthopedics Related Research . 2004 Aug;(425):82-6.
    65. 65. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Unexpected Collapse Pattern “Z” Pattern Proximal Migration Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31-7. 10.6 % . Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 3/55 cases 6% Tyllianakis M . at al Acta Orthop Belg. 2004 Oct;70(5):444-54 5/45 10.9%
    66. 66. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Unexpected Collapse Pattern “Reverse-Z” Pattern Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 2/55 cases 4% Distal Migration Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31-7. 21.6 %
    67. 67. Lateral Pillar Stability – Lateral Cortex Femur Clinical Problem Medial Displacement of Distal Fragment - Loss of Reduction
    68. 68. Lateral Pillar Stability – Lateral Cortex Femur 3. Technical Change - Solution 1. Preserve lateral cortex 2.Complete lateral support Small 6.4 mm triflange hip pins 12.6 mm proximal diameter Intramedu llary nail 3. Smooth sliding surface Barrels with rim Buttress slit plate Uniform continuous contact Lateral platform Stability with Collapsibility Novel Implant Assembly
    69. 69. Minimal Invasive Placement
    70. 70. F Stability with Collapsibility - Controlled collapse F
    71. 71. M/62yrs, Lateral Cortex Broken Badly Preoperative
    72. 72. 6wks . Post op Immediate. Post op
    73. 73. 12 wks . Post op
    74. 74. F/67yrs, Lateral Cortex Broken Badly Preoperative Immediate. Post op
    75. 75. 6wks . Post op 12 wks . Post op
    76. 76. May not need buttress plate Greater Trochanter Attachment TBW
    77. 77. Technical -Clinical Problem 3. Difficulty in Placement – Indian Bone dimensions Single Plane Jig and Nail Holes Proximal Nail Dimensions Distance between Holes- Large Pins Obstructive imaging- Jig
    78. 78. Two Plane - Nail Hole and Jig Precise Placement in two planes 4. Technical Change - Solution Parker M . – cutting out of hip screw related to its position in neck and head J .Bone Joint Surgery [Br] 1992; 74-B:625.
    79. 79. Two Plane - Nail Hole and Jig 4. Precise Placement in two planes Easy central placement in neck No need to rotate jig externally Distal locking 900 to AP plane
    80. 80. Two Plane –Nail Holes and Jig 4. Precise Placement in two planes Pre op CT 3 D Reconstruction Post op CT 3 D Reconstruction Equal Distribution of Forces - Intact Bone
    81. 81. Smaller proximal diameter 5. Technical Change - Solution 12.5 mm diameter • Avoids iatrogenic shattering of trochanter • Minimal injury –abductor function • Matches with Indian dimensions • More room for entry • No displacement of reduction on entry 17 mm Large Size-Shattering of Trochanter A.Herrera et al Sicot 2002 9 % 26% more preservation of bone stock
    82. 82. Reduced distance – from tip and between proximal holes, smaller hip pins 6. Technical Change - Solution Superior Cut Through Difficult Placement A.Herrera et al Sicot 2002 5% A.Y et al Injury. 2002 Jun;33 (5)9 8%. Avoids placement in sup. border Prevents superior cut thru – neck Technical complexity reduced
    83. 83. Technical change - Compact jig 7. Non Obstructive imaging- Jig - Clinical solution Two plane + compact jig do not obstruct lateral view Biological – Minimally invasive Technically simple –reproducible technique- cost effective
    84. 84. Technical -Clinical Problem 4. Profile of Implant mismatch with Proximal Femur Stress concentration at Tip – Pointing Effect 1. Anterior thigh pain 2. Fracture shaft femur at nail end 3. Difficult Distal Locking – Deformation of end International Orthopedics(SICOT) 2002 ,26; 365-369. A Comparative Study of trochanteric fractures treated with Gamma nail or the Proximal Femur Nail International Orthopedics(SICOT) 2001 ,25; 298-301. Trochanteric fractures treated with Proximal Femur Nail (AO)
    85. 85. Straight short nail - Anterior Curvature Femur Technical Problem Stress rising at single point or edge or surface – Pointing Effect Straight Nail in Curved Canal
    86. 86. • Video – animation showing on external rotation of jig –it touches anterior cortex more - no two plane and no anterior curvature
    87. 87. Congruent curvatures 8. Technical Change - Solution • Avoids anterior thigh pain (pointing effect) • Avoids stress rising • Avoids fracture beneath tip Curves in two planes
    88. 88. Straight short nail - Anterior Curvature Femur 8. Technical Problem - Solution Difficult Distal Locking Straight Nail in Curved Canal – Distal flexibility Deformation of nail- straight part Injury. 2002 Jun;33(5):395-9. The AO/ASIF proximal femoral nail (PFN) for the treatment of unstabletrochanteric femoral fracture. Al-yassari G, Langstaff RJ, Jones JW, Al-Lami M. Orthopaedic Department, Hillingdon Hospital, Pield Heath Road, Uxbridge,Middlesex UB83 NN, UK.
    89. 89. World Intellectual Property Organization (WIPO) Indian Patent Granted International and National Patent Process
    90. 90. Future Design Custom made design • • • • • • Measurements Neck breadth Neck shaft angle Medio lateral angle Canal diameters Anterior curvature Animated outcome
    91. 91. Take Home Message Factors - Fracture Implant Construct Stability 1. Quality of bone : Allow Augmentation 2. Fragment Geometry- Avoid Injury to Partly modifiable Not in Control lateral wall – trochanter – abductor - biology 3. Reduction Avoid displacement on entry –maintain reduction 4. Under Control Depends on Fracture Choice of Implant Rotational–varus – shear -lateral wall stability Controlled guided limited collapse Under Control 5. Implant Placement and profile allow ideal placement –match profile Under Control of proximal femur – technically reproducible Depends on design Chosen –average surgeon –cost effective
    92. 92. References - Bibliography 1. Rene Marti & Dunki Jacobs , Ph. Procter 1992 2. A. Herrera et al., International Orthopedics (SICOT 2002), 26:365-369 3. PASLE study Dr Balushankaran 4. Bergmann G, Deuretzbacher G, Claes L, Haas NP, Duda GN Clin Biomech (Bristol, Avon). 2001 Oct;16(8):644-9 5 J .of Orthop Trauma. 2007 Jul;19(6):432; Commers MB, Roth C, Hall H, Kam BC, Ehmke LW, Krieg JC, Madey SM, Bottlang M. 6. J Orthop Trauma. 2004 Jan;18(1):12-7 Intramedullary fixation of unstable intertrochanteric hip fractures: one or two lag screws. 7. J Orthop Surg Res. 2009; 4: 16, Comparison of migration behavior between single and dual lag screw implants for intertrochanteric fracture fixation 8. Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31-7. 9 Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 10. Tyllianakis M . at al Acta Orthop Belg. 2004 Oct;70(5):444-54 11. Boldin et al Acta Orthop Scand 2003; 74 (1): 53–58 12. Fogagnolo F et al Arch Orthop Trauma Surg. 2004 Jan;124(1):31- Dr Navin Thakkar naveenthakkar@gmail.com

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