SRI SIDDHARTHA MEDICAL COLLEGE,TUMKURDepartment of orthopaedics

Topic:Nailing Intertrochanteric Hip Fractures:

Short versus long; locked versus nonlocked

• Moderator:Dr. J.K ReddyProf. & HODDept. Of

Orthopaedics

• Presenter:Dr. Jaipalsinh MahidaResidentDept. Of Orthopaedics

introduction

• Occurs in the region between greater & lesser trochanters of the femur; often extending to the subtrochanteric region.• Extracapsular• Higher incidence between elderly population• Large number of implants developed

since 50s - compression/ sliding hip screw SHS- Gold standard of extramedullary device

In 80s - intramedullary devices

• Intramedullary nails represented fromShort & long nails entering from area of greater trochanterVarious diameterAnteversion anglesProximal configuration as far as shape, size & number of lag screwsShaft & distal end vary in

Radius of curvature Width Shape of nail tip Number, location & method of insertion/ guidance of distal locking screw.

• Type 33.A3 or unstable FractureBest treated with intramedullary device

• For stable fracturesSHS shows fewer complication rates & no worse functional outcome compared to

intramedullary nailClinical study do not match biomechanical data suggesting superiority of long distally

locked cephalomedullary nail over SHS for management of stable fractures

• Use of cephalomedullary nails has increased in last 15 years from 3% to 67% in USA & Europe

Shift is more impressive between younger generation of surgeonsHas interesting geographic variationsFollows introduction of 3rd & 4th generation nails

• However, contemporary understanding of advantages of IM nailing of extracapsular hip fractures dictates their use for unstable fractures, that is, those with reverse obliquity, with posteromedial comminution, compromised of fracrured lateral wall & clearly those with subtrochanteric extension.

• This article attempts to summarizeContemporary understanding of excisting biomechanical & clinical evidence of IM

nailing of IT fractures, as to weather they should be short or long nails spanning the whole length of femur, & use or not of distal locking screws.

Anatomy• IT fractures occur in the region between GT & LT of proximal femur,

occasionally extending into subtrochanteric region• These extracapsular fractures occur in cancellous bone with abundant blood

supply. As a result nonunion & osteonecrosis are not major problems, as in femoral neck fractures• Deforming muscle forces will usually produce Shortening, External rotation &

Varus position at fracture siteAbductors tend to displace GT laterally & proximallyIliopsoas displace LT medially & proximallyHip flexors, extensors & adductors pull distal fragment proximally

• Fracture stability is determined by presence of posteromedial bony contact, which act as a buttress against fracture collapse

Mechanism of injury• Most fractures results from direct impact to GT area• Younger individuals:

High energy injury such as motor vehicle accident or fall from height More common in men less than 40 years

• 90% of IT fractures in elderly results from a simple fall(higher in women)• Tendency to fall increases with patient age, poor vision,

decreased muscle power, labile blood pressure, decreased reflexes, vascular disease & coexisting musculoskeletal pathology

Cumming’s factors determining fracture at hip• The faller must be orientd to fall or “impact” near hip• Local soft tissue must absorb less energy than necessary to

prevent fracture(inadequate soft tissue- muscle/ fat coverage)• Protective responses must be inadequate to reduce the energy of

fall beyond a certain critical threshold• Residual energy of fall applied to proximal femur must exceed its

strength(i.e: bone strength at hip must be insufficient)

Imaging studies- x-rays• Pelvis with both hip- AP view• X-ray of affected hip- AP & cross-table lateral• Traction films (with internal rotation) – helpful in communited and

high – energy fractures and in determining implant selection• For subtrochanteric extension – femur AP & lateral view

Diagnosis and classification• Increased surgical complexity & recovery are associated with

UNSTABLE FRACTURE patternPosteromedial large separate fragmentationBasicervical patternReverse obliquity patternsDisplaced greater trochanteric(lateral wall fracture)Failure to reduce the fracture before internal fixation

Classification systems

• No single classification system that has achieved reliable reproductive validity• 1822- sir Astley Cooper (london) described the 1st (pre- radiographic)

classification of hip fractureIntra capsular ( main complication- non- union)Extracapsular (main complication – coxa vara)

Boyd & griffin classification• Type I : Fractures that extend along the intertrochanteric line• Type II : Comminuted fractures with main fracture line along

intertrochanteric line but with multiple secondary fracture lines• Type III: Fractures that extend to or are distal to the lesser trochanter• Type IV: fractures of the trochanteric region & proximal shaft with

fractures in at least 2 planes

• Type III & IV are most difficult types to manageAccounts for 1/3rd of trochanteric fractures

Evan’s classification:• Based on prereduction & postreduction stability, that is, the

convertibility of an unstable fracture configuration to a stable reduction• In stable fracture patterns , posteromedial cortex remains intact or has

minimal comminution, making it possible to obtain & maintain a stable reduction• Unstable fracture patterns are characterized by greater comminution of

posteromedial cortexThough inherently unstable, these fractures can be converted to a stable

reduction if medial cortical opposition is obtained

• Reverse obliquity pattern is inherently unstable because the tendency for medial displacement of femoral shaft

Ota/ao classification• Most quoted in recent scientific articles- a derivative of muller

classification• Has been very useful in evaluating results of treatment of IT fracture

& allowing comparisons among reports in literature.• Group 1 fractures (31 A1): fractures are not comminuted

Pertrochanteric simple((2-part) fractures with typical oblique fracture line extending from GT to medial cortex, lateral cortex of GT remains intact

A1.1 – along IT lineA1.2 – through GTA1.3 – below LT

• Group 2 fractures (31 A2): fractures have increasing comminuation.Pertrochanteric multifragmentary – comminuted fractures with posteromedial

fragment, lateral cortex of GT however remains intact. fractures are unstable, depending on size of medial fragment

A2.1 – with one intermediate fragmentA2.2 – with several intermediate fragments A2.3 – extending more than 1 cm below lesser trochanter

• Group 3 fractures (31 A3): fractures includes reverse obliquity or subtrochanteric extension

True IT- are those in which fracture line extends across both medial & lateral cortices; also includes reverse obliquity

A3.1 – simple obliqueA3.2 – simple transverseA3.3 – multifragmentary

Unusual fracture pattern• BASICERVICAL FRACTURES:• Located proximal to or along IT line• Although anatomically femoral neck fracture, they are usually

extracapsular and behave like IT fractures• At greater risk for osteonecrosis when compared to more distal IT

fractures• Lack cancellous intertrochanteric region & are more likely to sustain

rotation of the femoral head

Unusual fracture pattern• REVERSE OBLIQUITY:• Oblique fracture line extending from medial cortex proximally to lateral

cortex distally• Tendency to medial displacement due to pull of adductor muscles• Should be treated as subtrochanteric fractures

treatment1. Non operative:

Indicated only for patients who are at extreme medical risk for surgery; it may be considered for demented nonambukatory patients with mild hip pain

Nondisplaced fractures can be considered for non operative treatmentEarly bed to chair mobilization is important to avoid increased risks &

complications of prolonged recumbency, including poor pulmonary toilet, atelectasis, venous stasis, & pressure ulcerations

Resultant hip deformity is both expected & accepted in cases of displacements

• Prolonged bed rest in traction until fracture unites( 10 – 12 weeks)Buck’s traction Russell skeletal tractionBalanced traction in Thomas splintPlaster spica immobilizationDerotation boot

• Complications of non-operative treatment:UTIKnee stiffnessPneumoniaThromboembolic complications – resulting in high mortality rateFracture healing is accompanied by malunion & nonunion , varus deformity

& shortening

2. Operative:Goal is stable internal fixation to allow early mobilization & full weight

bearing ambulation. Stability of fracture fixation depends on

Bone quality Fracture pattern Fracture reduction Implant design Implant placement

• Operative methods:Plate constructCephalomedullary nailingArthroplastyExternal fixations

Advantages of cephalomedullary nails:• Because of its location theoretically it provides more efficient

load transfer than does a sliding hip screw• Shorter lever arm of IM device can be expected to decrease

tensile strain on implant, thereby decreasing risk of implant failure• Because IM fixation device incorporates a sliding hip screw,

advantage of controlled fracture impaction is maintained• Shorter operative time & less soft tissue dissection than sliding

hip screw

Proximal femoral nail• Shown to prevent fractures of femoral shaft by having a smaller distal

shaft diameter which reduces stress concentration at the tip• Due to its position close to weight-bearing axis stress generated on IM

implant Is negligible• It also acts as a buttress in preventing medicalization of the shaft. Entry

portal of PFN through trochanter limits surgical insult to tendinous hip abductor musculature only, unlike those nails which require entry through piriformis fossa• Total length: - standard nail- 240 mm

- short nail- 200 mm

Short versus long nails• Intertrochanteric Intramedullary nailing in general

is an antegrade insertion of femoral nail with wider proximal part & proximal slot which allows a single or couple of lag screws/or a blade to be inserted from lateral cortex of femur, passing through nail slot/s, across femoral neck, finishing at subchondral area of femoral head.

Initially nail length was short- finishing above level of isthemusAfter 1980s- long version nail spanning whole length of femoral shaft & ending at

supracondylar region was introduced

• Number of authors suggestsLong nail less likely to refracture than shortProvides more stable construct

• Review study of Norris et al:Included 13,568 IT fractures from 89 studiesAdvantage of long nail didn’t reach statistical significance(1.1% V/s 1.7%)But, Described improvement of performance of modern long nails Vs previous

design.

• Okcu et al :Study was underpowered & had short follow-upConclusion:

Reverse oblique fractures can be treated effectively with either short or long nails

• Hou et al:Excluded reverse oblique & fracture with subtrochanteric extension conclusion:

No clear benefit of elderly patients is offered by using a long nail in simple & multifragmentary IT fractures

• Kleweno et al :Largest series in current orthopaedic literature comparing short Vs long nailsIncluded all types of IT fracturesUsed 4 nail types20% patients lost to follow-upObservation:

Similar rate of periprosthetic fracture & reoperative rateso Reason for reoperation- cutout of head/neck component

Conclusion: no difference of failure rates with long and short nails

• Vaughn et al :Conclusion:

Similar results in catastrophic failures (periprosthetic fractures, proximal fixation failure, AVN femoral head) should be anticipated with both nails

More minor complications ( prominent lag or interlocking screw) reported with long nails

• In general and until any future contradicting evidence, long nails are preferable when longer working length is needed, i.e in comminuted fractures with subtrochanteric extension, or when protection of whole femoral shaft is necessary, i.e severe osteoporosis, known metastatic lesions, or suspected femoral pathology.

locked versus unlocked nails• Use of long or short nail with or without distal interlocking fixation has

been recommended for both stable and unstable IT fractures• IM nails bear most weight initially, & gradually transfers to bone as

fracture healing progresses• Load bearing of IM nail is largely dependent on fracture pattern and

reduction achieved• Reaming and distal locking allows transmission of physiological load to

proximal & distal end of nail threw screws

• In absence on interlocking screwsImplant transfer axial compaction motion along longitudinal axis of nail to bone

• With significant cortical contact, compressive loads will be supported in largely by bone cortices• Without cortical contact, all compressive loads will be transferred

distally through nail to distal interlocking screws, which resist fracture collapse and length loss until their fatigue failure or fracture healing• For axial &/or rotationally unstable fractures

Distal locking screws maintains fracture length, prevent limb shortening & subsequently increase fracture stability and allow early mobilization

• Roseblum et al:1800 N axial load in static locked or in unlocked modeDynamic loading & common rotational forces conditions not accounted in study

• Kane et al:Assessed rotational stiffness in stable IT fracture modelLocked nails provided statically stiffer construct than unlockedAuthor suggested

Locked distal construct may fatigue & break earlier when subjected to torsional loading

• Problems with distal locking screws:Acts as stress raiser causing subsequent implant breakagesoft tissue irritationdistal femoral condyle fractures

• Currently distal locking is dictated in IT fractures with either sever comminution or subtrochanteric distal extension or in gross osteopenia & ballooning of femoral diaphysis, to avoid painful toggling of nail into diaphyseal canal at early stage & malunion in form of loss of femoral length, malalignment & rotational deformity.

discussion• Phyiological loading of nail-bone construct of IT fracture treated with

IM nail comprises of 3 forces:1. Torsion2. Compression of medial aspect of nail3. Tension on lateral aspect

• Load bearing of IM nail largely depends on fracture pattern & achieved reduction• When Cortical contact across fracture site achieved

Large portion of compressive load is supported by cortices

• In Absence of cortical contactCompressive & rotational loads are transmitted distally through nail to distal

locking screws.

• Ist generation of short cephalomedullary nails Associated with unacceptable high rates (5%-23%) of perioperative

periprosthetic fractures, attributed to Nail jamming& abutment to posterolateral cortex High proximal nail valgus angle Excessively large distal diameters Inherent high material stiffness Poor canal preparation & distal interlocking insertion techniques

• use of long cephalomedullary nail was adoptedTo avoid above mentioned complicationsBenefit of spanning whole femurPreventing future periprosthetic fractures

• Use of long cephalomedullary nails was challenging in stable subtype IT fractures

Increased blood loss after reamingElongation of operative timeIncreased radiation exposure for distal interlocking screwEffective distal targetingAnterior encroachment of nail at supracondylar region

• Improved characteristics of newer generation short & long nailsFlexibility of materialReplication of specific anatomic characteristic of femur

Radius of curvature Version & size of proximal femur Neck shaft angle

Tapered stems & smaller locking screws

• No high level clinical evidence exist to reach safe conclusion regarding optimal use of cephalomedullary nails over sliding hip screw, at least for stable IT fractures

• Comparison of clinical end point between studies using nails of different generations, designs, characteristics of existing meta-analysis remains frustrating inconclusive.

• Author believes that for unstable or reverse oblique fractures, there is no adequate evidence to support any deviation from current practice, which is consistent with use of long statically locked nails.

• More studies required

Thank You