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

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

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

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

Anterior and posterior stress-radiography The same apparatus is used for both anterior and posterior tests 20° of flexion20° of flexion Fixed load (9 kg)Fixed load (9 kg) Free translationFree translation Free rotationFree rotation Comfortable for the patientsComfortable for the patients

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

Landmarks Lateral condyle : anterior notch and posterior angle

ATMC

ATLC

ATMC and ATLC ATMC and ATLC Anterior radiological drawer

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

1050 knees measured 487 ACL insufficient knees 487 contra-lateral normal knees 76 normal subjects age : 27.5 ± 9 years ( ) 70.5 % males, 29.5 % females no previous surgery no meniscus bucket-handle Materiel

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 Methods

Normal Deficient ACL ATMC0.91 ( ) 0.95 ( ) 0.97 ( ) 0.98 ( ) ATLC0.92 ( ) 0.92 ( ) 0.93 ( ) 0.95 ( ) Intra and interobserver intraclass correlation for ATMC and ATLC All values include 95 % confidence intervals

Right-left difference 38 normal subjects A nt T ransl M edial C omp : 0.5 ± 0.4 mm A nt T ransl L ateral C omp : 1.2 ± 0.4 mm P ost T ransl M edial C omp : 1.1 ± 0.7 mm P ost T ransl L ateral C omp : 1.5 ± 1.2 mm RESULTS

ATMC = 10.4 ± 4.3 ATLC = 18.5 ± 5.1 PTMC = 2.7 ± 2.9 PTLC = 1.1 ± 4.1 ATMC = 2.1 ± 2.6 ATLC = 10.5 ± 3.5 PTMC = 2.1 ± 2.9 PTLC = 1.7 ± normal knees478 ACL deficient knees No difference between males and females RESULTS

No difference for posterior translation (ACL ruptured or not ) Posterior position is different from the radiological "zero position" It is the "starting position" for clinical tests and for arthrometric measurements RESULTS PTMC = 2.1 ± 2.9 PTLC = 1.7 ± 4.1

specificity = 90 %specificity = 90 % sensitivity = 87 %sensitivity = 87 % predict posit. val = 89 %predict posit. val = 89 % predict negat. val = 88 %predict negat. val = 88 % 87%87% 79 %79 % 85 %85 % 82 %82 % ATMC ATLC Cut point : 6 mmCut point : 11.5 mm Diagnosis of ACL rupture The ATMC is the most reliable

Medial Compartment PTMC +ATMC 4.2 ± 2.7 mm Physiological ant-post laxity Lateral Compartiment PTLC +ATLC 12.2 ± 4.5 mm

Medial Compartment PTMC +ATMC 12.1 ± 4.5 mm Pathological ant-post laxity 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 ATLC 7.5 ± 4.6 mm ATMC 8.1 ± 4.2 mm

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

Anterior laxities classification ATMC Cases number %

Anterior laxities : grade Diff. Laxity mm zero position line 15

Anterior laxities : grade Diff. Laxity zero position line 15 ATMC knees

Anterior laxities : grade Diff. Laxity zero position line 15 ATMC ATLC 1 D 1 C 1 B 1 A

Anterior laxities : grade Diff. Laxity zero position line 15 ATMC ATLC 1 D 1 C 1 B 1 A

Anterior laxities : grade Diff. Laxity zero position line 15 ATMC ATLC 1 D 1 C 1 B 1 A

Anterior laxities : grade Diff. Laxity zero position line 15 ATMC ATLC 1 D 1 C 1 B 1 A

Diff. Laxity Zero position line 15 Anterior laxity : grade 2 ATMC ATLC 2 D 2 C 2 B 2 A

Anterior laxity : grade 3 Anterior laxity : grade Diff. Laxity Zero position line 15 3 D 3 C 3 B 3 A ATMC ATLC

Anterior laxity : grade Diff. Laxity zero position line 15 4 D 4 C 4 B 4 A ATLC ATMC

Anterior laxity : grade Diff. Laxity zero position line 15 4 D 4 C 4 B 4 A ATLC ATMC

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

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

Prospective surgery isolated ACL ACL + extra-articular lateral reconstruction

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

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

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

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

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

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

« Knee instability after injury to the anterior cruciate ligament Quantification of the Lachman test » JL Lerat, B Moyen, F Cladière, JL Besse, H Abidi J. Bone Joint Surgery VOL. 82-B, N°1, January 2000,

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