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 Lerat (manually) : 1979 Lerat (apparatus) : 1982 Stäubli, Jakob : 1982 Hooper : 1986 Iversen : 1988 l apparatus 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

Lateral condyle : anterior notch and posterior angle 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 age : 27.5 ± 9 years (16-50) 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 Normal Deficient ACL ATMC 0.91 (0.85 - 0.95) 0.95 (0.90 - 0.98) 0.97 (0.95 - 0.98) 0.98 (0.94 - 0.98) ATLC 0.92 (0.85 - 0.95) 0.92 (0.85 - 0.95) 0.93 (0.89 - 0.96) 0.95 (0.92 - 0.97)

RESULTS Right-left difference Post Transl Medial Comp : 1.1 ± 0.7 mm 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

No difference between males and females 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 ) Posterior position is different from the radiological "zero position" It is the "starting position" for clinical tests and for arthrometric measurements PTMC = 2.1 ± 2.9 PTLC = 1.7 ± 4.1

Diagnosis of ACL rupture The ATMC is the most reliable ATLC Cut point : 6 mm 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 ATMC 15 11 8 5 128 knees zero position line

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

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

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

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

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

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

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

Anterior laxity : grade 4 ATMC ATLC Diff. Laxity 15 91 24 4 D 4 C 4 B 4 A 11 37 8 19 5 11 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 Grade 2 Grade 1 n = 487 A B C D

ACL + extra-articular lateral reconstruction Prospective surgery ACL + extra-articular lateral reconstruction isolated ACL

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

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

"Mac InJones » 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