Stressradiography of the knee Anterior and posterior translation

Stress-radiography of the knee Anterior and posterior translation at 20° of flexion in 563 normal knees and 487 ACL deficient knees JL. LERAT, JL. BESSE, F. CHOTEL, F. CLADIERE, B. MOYEN Department of Orthopaedic Surgery and Sports Medicine Lyon – France ESSKA, Nice, 5 -1998 EFORT, Bruxelles 3 -8 June 1999

Aims of the study • The measurements of anterior and posterior laxity – in normal knees – and in ACL deficient knees • Diagnosis value • Grading the knee play in order to choose adaptated surgery

Anterior stress-radiography Flexion : 90° • • Nyga : 1970 Kennedy, Fowler : 1971 Lerat : 1971 Jacobsen : 1976

Anterior stress-radiography TORG introduced the "LACHMAN test" in 1976 Test practised since 1963 by TRILLAT in Lyon-France

Anterior stress-radiography Manualy 20° of flexion • • • l Lerat (manually) : 1979 Lerat (apparatus) : 1982 Stäubli, Jakob : 1982 Hooper : 1986 Iversen : 1988 apparatus

Anterior and posterior stress-radiography The same apparatus is used for both anterior and posterior tests • • • 20° of flexion Fixed load (9 kg) Free translation Free rotation Comfortable for the patients

Anterior translation of the tibia • Posterior tibial cortex as reference line • • Parallels tangent to the posterior aspect of the condyles Distance between these tangent lines and the tibial compartments ATMC: Anterior Translation of Medial Compartment ATLC : Anterior Translation of Lateral Compartment

Landmarks Lateral condyle : anterior notch and posterior angle

ATMC

ATLC

Anterior radiological drawer ATMC and ATLC

Posterior translation of the tibia PTMC = Posterior Translation of Medial Compartment PTLC = Posterior Translation of Lateral Compartment

Materiel • 1050 knees measured • 487 ACL insufficient knees • 487 contra-lateral normal knees • 76 normal subjects • age : 27. 5 ± 9 years (16 -50) • 70. 5 % males, 29. 5 % females • no previous surgery • no meniscus bucket-handle

methods • 2100 X-ray films • 4200 measurements • One observer (JL L)

Methods Interobserver intraclass correlation 3 observers 50 patients measured (ruptured ACL - normal knee) Intraobserver intraclass correlation 1 observer measured 50 patients twice

Intra and interobserver intraclass correlation for ATMC and ATLC All values include 95 % confidence intervals ATMC ATLC Normal 0. 91 (0. 85 - 0. 95) 0. 97 (0. 95 - 0. 98) 0. 92 (0. 85 - 0. 95) 0. 93 (0. 89 - 0. 96) Deficient ACL 0. 95 (0. 90 - 0. 98) 0. 98 (0. 94 - 0. 98) 0. 92 (0. 85 - 0. 95) 0. 95 (0. 92 - 0. 97)

RESULTS Right-left difference 38 normal subjects Ant Transl Medial Comp : 0. 5 ± 0. 4 mm Ant Transl Lateral Comp : 1. 2 ± 0. 4 mm Post Transl Medial Comp : 1. 1 ± 0. 7 mm Post Transl Lateral Comp : 1. 5 ± 1. 2 mm

RESULTS 563 normal knees 478 ACL deficient knees ATMC = 2. 1 ± 2. 6 ATLC = 10. 5 ± 3. 5 PTMC = 2. 1 ± 2. 9 PTLC = 1. 7 ± 4. 1 ATMC = 10. 4 ± 4. 3 ATLC = 18. 5 ± 5. 1 PTMC = 2. 7 ± 2. 9 PTLC = 1. 1 ± 4. 1 No difference between males and females

RESULTS • No difference for posterior translation (ACL ruptured or not ) PTMC = 2. 1 ± 2. 9 PTLC = 1. 7 ± 4. 1 • Posterior position is different from the radiological "zero position" • It is the "starting position" for clinical tests and for arthrometric measurements

Diagnosis of ACL rupture The ATMC is the most reliable ATMC Cut point : 6 mm • • ATLC Cut point : 11. 5 mm specificity = 90 % sensitivity = 87 % predict posit. val = 89 % predict negat. val = 88 % • • 87% 79 % 85 % 82 %

Physiological ant-post laxity Medial Compartment PTMC +ATMC 4. 2 ± 2. 7 mm Lateral Compartiment PTLC +ATLC 12. 2 ± 4. 5 mm

Pathological ant-post laxity Medial Compartment PTMC +ATMC 12. 1 ± 4. 5 mm Lateral Compartiment PTLC +ATLC 19. 4 ± 5. 5 mm

Considering differential laxity Pathological ATMC and ATLC Normal contralateral knee

ACL deficient knees : differential ant. translation ATMC 8. 1 ± 4. 2 mm ATLC 7. 5 ± 4. 6 mm

Anterior laxities classification • Translation of the lateral side can be predominent internal tibial rotation • Translation of the medial side can be predominent external tibial rotation

Anterior laxities classification Cases number % ATMC

Anterior laxities : grade 1 Diff. Laxity mm 15 11 8 5 zero position line

Anterior laxities : grade 1 Diff. Laxity 15 ATMC 11 8 5 128 knees zero position line

Anterior laxities : grade 1 Diff. Laxity 15 ATMC ATLC 1 D 11 1 C 8 1 B 5 128 zero position line 59 1 A

Anterior laxities : grade 1 Diff. Laxity 15 ATMC ATLC 1 D 11 1 C 8 5 128 zero position line 36 1 B 59 1 A

Anterior laxities : grade 1 Diff. Laxity 15 ATMC ATLC 1 D 11 8 5 128 zero position line 22 1 C 36 1 B 59 1 A

Anterior laxities : grade 1 Diff. Laxity 15 ATMC 11 8 5 128 zero position line ATLC 11 1 D 22 1 C 36 1 B 59 1 A

Anterior laxity : grade 2 Diff. Laxity 15 ATMC ATLC 11 18 2 D 8 25 2 C 25 2 B 48 2 A 5 116 Zero position line

Anterior laxity : grade 3 Diff. Laxity 15 11 8 ATMC 109 5 Zero position line ATLC 29 3 D 26 3 C 19 3 B 35 3 A

Anterior laxity : grade 4 Diff. Laxity ATMC ATLC 15 11 91 4 D 4 C 8 5 zero position line 19 4 B 11 4 A

Anterior laxity : grade 4 Diff. Laxity ATMC ATLC 91 24 4 D 37 4 C 19 4 B 11 4 A 15 11 8 5 zero position line

Anterior laxities classification Grade 4 Grade 3 Grade 2 Grade 1 ATMC (first number) : 4 grades ATLC (A, B, C or D) : 4 grades

Anterior laxities classification Number of cases for all categories ( % ) Grade 4 Grade 3 n = 487 Grade 2 Grade 1 A B C D

Prospective surgery isolated ACL + extra-articular lateral reconstruction

Prospective surgery ACL + medial + lateral 19 % 26 % 38 % 17 % isolated ACL + extra articular lateral reconstruction

Precice and objective measurement of preop and post-op laxity Preoperative ATMC and ATLC Post op 10 years

"Mac In. Jones » procedure ACL reconstruction with patellar tendon Quadricipital tendon is stretched from the condyle to the Gerdy’s tubercule with solid sutures

Evolution of radiological laxity after surgery ACL reconstruction + lateral plasty : 100 cases Differential left/right laxity Gain for ATMC : 62 % Gain for ATLC : 77 %

In the same way, a prospective study is started to evaluate postero-medial reconstruction

Conclusions • Conclusive diagnosis for ACL rupture • Better comprehension of laxity physiopathology • Laxities classification • Judicious surgical treatment adaptated to the lesions

THANK YOU

Medial laxity : what i do ?

1/Tensioning of distal insertion

2/ Tensioning of proximal insertion

3/ Tension without detaching the distal and proximal insertions using semi tendinosus or quadricipital tendon

3/ Tension without detaching the distal and proximal insertions