sliding hip screw fixation for proximal femur fractures: an analysis of the predictive factors of...
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SLIDING HIP SCREW FIXATION FOR SLIDING HIP SCREW FIXATION FOR PROXIMAL FEMUR FRACTURES: PROXIMAL FEMUR FRACTURES:
AN ANALYSIS OF THE PREDICTIVE AN ANALYSIS OF THE PREDICTIVE FACTORS OF FAILUREFACTORS OF FAILURE
Dr Tao Shan LimDr Tao Shan Lim MBBS Grad Dip Surg AnatMBBS Grad Dip Surg Anat
Mr Karl Stoffel Mr Karl Stoffel MDMD
Dr Rochelle Nicholls Dr Rochelle Nicholls PhDPhDDr Bianca Billik Dr Bianca Billik MBBSMBBS
Fremantle Orthopaedic UnitFremantle Orthopaedic UnitFremantle HospitalFremantle HospitalWestern AustraliaWestern Australia
The Sliding Hip ScrewThe Sliding Hip Screw
Trochanteric region #’sTrochanteric region #’s
Maximises healing potentialMaximises healing potential
Elderly / co-morbiditiesElderly / co-morbidities
FailureFailure
8 – 23% 8 – 23%
Bone qualityBone quality
Fragment geometryFragment geometry
ReductionReduction
Implant placementImplant placement
Kaufer, Clinical Orthopaedics 1980, Jan-Feb:53–61.Dodds & Baumgaertner, Current Opinion in Orthopedics 2004, Feb:12-17
Baumgaertner, 1995Baumgaertner, 1995
Tip – Apex Distance > 25mmTip – Apex Distance > 25mm
19 failures in 198 fractures (9.6%)19 failures in 198 fractures (9.6%)– 16 cut out16 cut out
Baumgaertner et al, J Bone Joint Surg Am. 1995 Jul;77(7):1058-64
Baumgaertner, 1995Baumgaertner, 1995
Tip – Apex Distance > 25mmTip – Apex Distance > 25mm
19 failures in 198 fractures (9.6%)19 failures in 198 fractures (9.6%)– 16 cut out16 cut out
5 different devices5 different devices– 142 sliding hip screw 142 sliding hip screw (3 manufacturers)(3 manufacturers)
– 56 intramedullary nail 56 intramedullary nail (2 manufacturers)(2 manufacturers)
Baumgaertner et al, J Bone Joint Surg Am. 1995 Jul;77(7):1058-64
Study AimsStudy Aims
Local experience of useLocal experience of use
– Dynamic Hip ScrewDynamic Hip Screw
– Exclusive use since March Exclusive use since March 20012001
Identify failuresIdentify failures
Identify predictive factorsIdentify predictive factors
Study DesignStudy Design
Retrospective radiological auditRetrospective radiological audit
731 cases731 cases
701 patients701 patients
2002 – 20042002 – 2004
Inclusion CriteriaInclusion Criteria
New adult proximal femur fractureNew adult proximal femur fracture
Adequate imagingAdequate imaging– PreoperativePreoperative– Implant Implant
MethodsMethods
Theatre databaseTheatre database
Ortho techsOrtho techs
PACSPACS
Revision Revision – CauseCause
PACSPACS
Picture Archiving Computer SystemPicture Archiving Computer System
Fremantle HospitalFremantle Hospital– 20012001
Sir Charles Gairdner HospitalSir Charles Gairdner Hospital– 20042004
Royal Perth HospitalRoyal Perth Hospital– 20042004
Fracture ClassificationFracture Classification
AO / MullerAO / Muller
Evan’sEvan’s
Müller et al; Manual of internal fixation: techniques recommended by the AO-ASIF group, ed 3, Berlin, 1991, Springer-Verlag
Fracture ClassificationFracture Classification
AO / MullerAO / Muller
Evan’sEvan’s
Evan E. J Bone Joint Surg 1949;31B:190–203
X-raysX-rays
1. Reduction1. Reduction Alignment APAlignment AP
Normal or slight valgusNormal or slight valgus
Alignment LateralAlignment Lateral
Less than 20 degrees tilt Less than 20 degrees tilt of femoral headof femoral head
X-raysX-rays
1. Reduction1. Reduction DisplacementDisplacement
Less than 5mm Less than 5mm displacement of any displacement of any bone fragmentbone fragment
X-raysX-rays
1. Reduction1. Reduction
2. Tip – Apex 2. Tip – Apex DistanceDistance
Baumgaertner et al, J Bone Joint Surg Am. 1995 Jul;77(7):1058-64
X-raysX-rays
1. Reduction1. Reduction
2. Tip – Apex 2. Tip – Apex DistanceDistance
3. Position of screw 3. Position of screw in femoral headin femoral head
Cleveland et al, J Bone Joint Surg Am. 1959 Dec;41-A:1399-408
Exclusion CriteriaExclusion Criteria
Not a fractureNot a fracture– 1 case (myeloma)1 case (myeloma)
Inadequate imagingInadequate imaging– 11 cases11 cases
DemographicsDemographics
387 Females, 120 Males387 Females, 120 Males– Female : Male 2.79 : 1Female : Male 2.79 : 1
Mean age 80.9 years Mean age 80.9 years – Range 15.0 – 106.2 Range 15.0 – 106.2 – SD 13.0SD 13.0
AgeAge
Above 9080-9070-8060-7050-60Below 50
AgeStrat_6
50.0%
40.0%
30.0%
20.0%
10.0%
0.0%
Per
cent
21%
43%
23%
6%3%3%
ASA ScoreASA Score
54321
ASA
60.0%
50.0%
40.0%
30.0%
20.0%
10.0%
0.0%
Per
cent
0%
12%
58%
24%
6%
Radiological Follow UpRadiological Follow Up
Intraoperative onlyIntraoperative only 25.3%25.3%
Postoperative X-ray within 2 weeksPostoperative X-ray within 2 weeks 33.8%33.8%
X-ray between 2 weeks and 3 monthsX-ray between 2 weeks and 3 months 17.9%17.9%
X-ray after 3 monthsX-ray after 3 months 23.0%23.0%
SurgeonSurgeon
ConsultantConsultant 10.7%10.7% 41 min41 min
FellowFellow 1.8%1.8% 43 min43 min
Training registrarTraining registrar 50.6%50.6% 39 min39 min
Service registrarService registrar 36.9%36.9% 50 min50 min
SurgeonSurgeon
ConsultantConsultant 10.7%10.7% 41 min41 min
FellowFellow 1.8%1.8% 43 min43 min
Training registrarTraining registrar 50.6%50.6% 39 min39 min
Service registrarService registrar 36.9%36.9%50 min50 min
PP < 0.001 < 0.001
Fracture RegionFracture Region
22.4% 22.4% 76.3% 1.2%76.3% 1.2%
N = 164 N = 164 N = 407 N = 9N = 407 N = 9
Trochanter Trochanter vs Neckvs Neck
AgeAge
(years)(years)
ASAASA Contralateral Contralateral #NOF#NOF
82.782.7 2.852.85 11.5%11.5%
75.175.1 2.522.52 6.7%6.7%
AO / Muller ClassificationAO / Muller Classification
266266 46.9%46.9%
235235 41.4%41.4%
5757 10.1%10.1%
N = 9N = 9
N = 9N = 9
AO / Muller ClassificationAO / Muller Classification
266266 46.9%46.9%
235235 41.4%41.4%
5757 10.1%10.1%
N = 9N = 9
N = 9N = 9
AO / Muller ClassificationAO / Muller Classification
266266 46.9%46.9%
235235 41.4%41.4%
5757 10.1%10.1%
N = 9N = 9
N = 9N = 9
Evan’s ClassificationEvan’s Classification
73.7%73.7%
N = 418N = 418
26.3%26.3%
N = 149N = 149
ReductionReduction
GoodGood 336336 59.3%59.3%
AcceptableAcceptable 125125 22.0%22.0%
PoorPoor 106106 18.7%18.7%
Cleveland ZoneCleveland Zone
Tip – Apex DistanceTip – Apex Distance
Mean 20mmMean 20mm– RangeRange 5 to 44 5 to 44– SD 6.1SD 6.1
Stable ≈ unstableStable ≈ unstable– 20 vs 22 mm20 vs 22 mm
Tip – Apex DistanceTip – Apex Distance
FailuresFailures
14 revisions - 2.5%14 revisions - 2.5%– In 567 cases!In 567 cases!
10 cut out10 cut out– Superior breach of Superior breach of
femoral headfemoral head
4 failures of plate 4 failures of plate screwsscrews– ““Reverse cut out”Reverse cut out”
FailuresFailures
14 revisions - 2.5%14 revisions - 2.5%– In 567 cases!In 567 cases!
10 cut out10 cut out– Superior breach of Superior breach of
femoral headfemoral head
4 failures of plate 4 failures of plate screwsscrews– ““Reverse cut out”Reverse cut out”
FailuresFailures
14 revisions - 2.5%14 revisions - 2.5%– In 567 cases!In 567 cases!
10 cut out10 cut out– Superior breach of Superior breach of
femoral headfemoral head
4 failures of plate 4 failures of plate screwsscrews– ““Reverse cut out”Reverse cut out”
Cut Out - TADCut Out - TAD
PP < 0.001 < 0.001
Cut Out - TADCut Out - TAD
Cut OutCut Out
TAD < 25TAD < 25 TAD ≥ 25TAD ≥ 25
YesYes 00 1010
NoNo 437437 120120
TotalTotal 0%0% 7.7%7.7%
Cut OutCut Out
Evan’s UnstableEvan’s Unstable– 10 of 1010 of 10
Displacement > 4mmDisplacement > 4mm– 10 of 1010 of 10
Varus reductionVarus reduction– 8 of 108 of 10
Cut Out – Cleveland ZoneCut Out – Cleveland Zone
Cut Out – Cleveland ZoneCut Out – Cleveland Zone
Cut Out – Cleveland ZoneCut Out – Cleveland Zone
Cut Out – Cleveland ZoneCut Out – Cleveland Zone
Bivariate RegressionBivariate Regression
RankRank VariableVariable P valueP value
11 Tip-Apex DistanceTip-Apex Distance 1.86 x 10 1.86 x 10 -8-8
22 Evan’s UnstableEvan’s Unstable 9.10 x 10 9.10 x 10 -8-8
33 Poor ReductionPoor Reduction 5.25 x 10 5.25 x 10 -7-7
44 Inferior Posterior Hip ScrewInferior Posterior Hip Screw 9.85 x 10 9.85 x 10 -6-6
55 Superior Anterior Hip ScrewSuperior Anterior Hip Screw 3.11 x 10 3.11 x 10 -5-5
Multivariate RegressionMultivariate Regression
RankRank VariableVariable P valueP value
11 Tip-Apex DistanceTip-Apex Distance 1.58 x 10 1.58 x 10 -6-6
22 Evan’s UnstableEvan’s Unstable 4.30 x 10 4.30 x 10 -3-3
33 Poor Reduction Poor Reduction 6.21 x 10 6.21 x 10 -1-1
Failure Rate of 2.5%?Failure Rate of 2.5%?
Choice of implantChoice of implant– Less unstableLess unstable
Quality of resultsQuality of results– Mean TAD 20mm (Baumgaertner 25mm)Mean TAD 20mm (Baumgaertner 25mm)
Computerised PACSComputerised PACS– Statewide tertiary catchmentStatewide tertiary catchment
Failure Rate of 2.5%?Failure Rate of 2.5%?
0
10
20
30
40
50
60
2002 2003 2004
PFN Usage
Failure Rate of 2.5%?Failure Rate of 2.5%?
Choice of implantChoice of implant– Less unstableLess unstable
Quality of resultsQuality of results– Mean TAD 20mm (Baumgaertner 25mm)Mean TAD 20mm (Baumgaertner 25mm)
Computerised PACSComputerised PACS– Statewide tertiary catchmentStatewide tertiary catchment
Failure Rate of 2.5%?Failure Rate of 2.5%?
Choice of implantChoice of implant– Less unstableLess unstable
Quality of resultsQuality of results– Mean TAD 20mm (Baumgaertner 25mm)Mean TAD 20mm (Baumgaertner 25mm)
Computerised PACSComputerised PACS– Statewide tertiary catchmentStatewide tertiary catchment
Study WeaknessesStudy Weaknesses
Level IV evidenceLevel IV evidence
Observer biasObserver bias
Loss of failures to the private sectorLoss of failures to the private sector
? X-rays on clinical need? X-rays on clinical need
SummarySummary
Accurate reflection of experienceAccurate reflection of experience
Captures all complications and revisions in Captures all complications and revisions in Western Australian tertiary centresWestern Australian tertiary centres
AcknowledgementsAcknowledgements
Synthes AustraliaSynthes Australia– Ben FraserBen Fraser
FH, SCGH, RPH Orthopaedic TechniciansFH, SCGH, RPH Orthopaedic Technicians– Particularly Steve and Ken from FremantleParticularly Steve and Ken from Fremantle
My wife May My wife May – Data entry!Data entry!
Insurance StatusInsurance StatusInsuranceInsurance NN %%
HOHO 591591 80.8%80.8%
VAVA 8080 10.9%10.9%
PIPI 3838 5.2%5.2%
MVMV 1414 1.9%1.9%
OVOV 6 6 0.8%0.8%
WCWC 22 0.3%0.3%
Plate LengthPlate Length
LengthLength NN %%
2 hole2 hole 1515 2.6%2.6%
4 hole4 hole 522522 92.1%92.1%
5 hole5 hole 1616 2.8%2.8%
6 hole6 hole 1111 1.9%1.9%
8 hole8 hole 22 0.4%0.4%
12 hole12 hole 11 0.2%0.2%
Plate AnglePlate Angle
AngleAngle NN %%
130 deg130 deg 122122 21.5%21.5%
135 deg135 deg 386386 68.1%68.1%
140 deg140 deg 4646 8.1%8.1%
145 deg145 deg 1010 1.8%1.8%
150 deg150 deg 33 0.5%0.5%
DHS ExtrasDHS Extras
ImplantImplant NN %%
Trochanteric Side PlateTrochanteric Side Plate 1212 2.1%2.1%
Antirotation Screw Antirotation Screw 77 1.2%1.2%