Advertisement

Posterior Tibial Slope Measurements Using the Anatomic Axis Are Significantly Increased Compared With Those That Use the Mechanical Axis

Published:September 16, 2020DOI:https://doi.org/10.1016/j.arthro.2020.09.006

      Purpose

      To compare posterior tibial slope (PTS) measurements from standard lateral knee radiographs with measurements from full-length lateral tibia radiographs.

      Methods

      We performed a multicenter, prospective study. Lateral knee and full-length lateral tibia radiographs were obtained for each patient, and PTS was measured. Slope measurements were obtained by measuring the angle between an average of the medial and lateral tibial plateaus and a representative tibial diaphysis line. The proximal anatomic axis was measured on lateral knee radiographs, and both the mechanical axis and anatomic axis were measured on full-length lateral tibia radiographs. The mechanical axis was defined as the center of the plateau to the center of the plafond, and the anatomic axis was defined as the center of the tibial diaphysis. The minimal clinically significant difference was defined a priori as 2° of PTS or greater.

      Results

      A total of 140 patients met the inclusion criteria. The average PTS using the proximal anatomic axis was 11.6° ± 3.2° on lateral knee radiographs; the PTS measured on full-length lateral tibia radiographs was 9.5° ± 3.4° using the mechanical axis and 11.8° ± 3.1° using the anatomic axis. There was a significant difference between the measurements with the mechanical axis and both anatomic axis measurements (P < .01) but no significant difference between the 2 anatomic axis measurement techniques (P = .574). In total, 55% of patients (n = 77) had a 2° or greater difference between the proximal anatomic axis and mechanical axis PTS measurement techniques.

      Conclusions

      There was no significant difference between PTS measurements that used the proximal anatomic axis from lateral knee radiographs and those that used the anatomic axis from full-length lateral tibia radiographs. Thus, lateral knee radiographs are adequate to accurately obtain tibial slope measurements. However, there was a significant difference between PTS measurements that used the anatomic axis and those that used the mechanical axis of the tibia.

      Clinical Relevance

      It is recommended that future studies report tibial slope based upon measurements that utilize the anatomic axis in order to ensure that subsequent conclusions are comparable, independent of the radiographic view.
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Matsuda S.
        • Miura H.
        • Nagamine R.
        • et al.
        Posterior tibial slope in the normal and varus knee.
        Am J Knee Surg. 1999; 12: 165-168
        • Kang K.-T.
        • Kwon S.K.
        • Son J.
        • Kwon O.-R.
        • Lee J.-S.
        • Koh Y.-G.
        The increase in posterior tibial slope provides a positive biomechanical effect in posterior-stabilized total knee arthroplasty.
        Knee Surg Sport Traumatol Arthrosc. 2018; 26: 3188-3195
        • Dai Y.
        • Cross M.B.
        • Angibaud L.D.
        • Hamad C.
        • Jung A.
        • Jenny J.-Y.
        Posterior tibial slope impacts intraoperatively measured mid-flexion anteroposterior kinematics during cruciate-retaining total knee arthroplasty.
        Knee Surg Sport Traumatol Arthrosc. 2018; 26: 3325-3332
        • Bernhardson A.S.
        • DePhillipo N.N.
        • Daney B.T.
        • Kennedy M.I.
        • Aman Z.S.
        • LaPrade R.F.
        Posterior tibial slope and risk of posterior cruciate ligament injury.
        Am J Sports Med. 2019; 47: 312-317
        • Webb J.M.
        • Salmon L.J.
        • Leclerc E.
        • Pinczewski L.A.
        • Roe J.P.
        Posterior tibial slope and further anterior cruciate ligament injuries in the anterior cruciate ligament–reconstructed patient.
        Am J Sports Med. 2013; 41: 2800-2804
        • Todd M.S.
        • Lalliss S.
        • Garcia E.
        • DeBerardino T.M.
        • Cameron K.L.
        The relationship between posterior tibial slope and anterior cruciate ligament injuries.
        Am J Sports Med. 2010; 38: 63-67
        • Bernhardson A.S.
        • DePhillipo N.N.
        • Aman Z.S.
        • Kennedy M.I.
        • Dornan G.J.
        • LaPrade R.F.
        Decreased posterior tibial slope does not affect postoperative posterior knee laxity after double-bundle posterior cruciate ligament reconstruction.
        Am J Sports Med. 2019; 47: 318-323
        • Christensen J.J.
        • Krych A.J.
        • Engasser W.M.
        • Vanhees M.K.
        • Collins M.S.
        • Dahm D.L.
        Lateral tibial posterior slope is increased in patients with early graft failure after anterior cruciate ligament reconstruction.
        Am J Sports Med. 2015; 43: 2510-2514
        • Khan M.S.
        • Seon J.K.
        • Song E.K.
        Risk factors for anterior cruciate ligament injury: Assessment of tibial plateau anatomic variables on conventional MRI using a new combined method.
        Int Orthop. 2011; 35: 1251-1256
        • Giffin J.R.
        • Vogrin T.M.
        • Zantop T.
        • Woo S.L.-Y.
        • Harner C.D.
        Effects of increasing tibial slope on the biomechanics of the knee.
        Am J Sports Med. 2004; 32: 376-382
        • Mitchell J.J.
        • Cinque M.E.
        • Dornan G.J.
        • et al.
        Primary versus revision anterior cruciate ligament reconstruction: Patient demographics, radiographic findings, and associated lesions.
        Arthroscopy. 2018; 34: 695-703
        • Salmon L.J.
        • Heath E.
        • Akrawi H.
        • Roe J.P.
        • Linklater J.
        • Pinczewski L.A.
        20-Year outcomes of anterior cruciate ligament reconstruction with hamstring tendon autograft: The catastrophic effect of age and posterior tibial slope.
        Am J Sports Med. 2018; 46: 531-543
        • Bernhardson A.S.
        • Aman Z.S.
        • DePhillipo N.N.
        • et al.
        Tibial slope and its effect on graft force in posterior cruciate ligament reconstructions.
        Am J Sports Med. 2019; 47: 1168-1174
        • Gwinner C.
        • Weiler A.
        • Roider M.
        • Schaefer F.M.
        • Jung T.M.
        Tibial slope strongly influences knee stability after posterior cruciate ligament reconstruction.
        Am J Sports Med. 2017; 45: 355-361
        • Nunley R.M.
        • Nam D.
        • Johnson S.R.
        • Barnes C.L.
        Extreme variability in posterior slope of the proximal tibia: Measurements on 2395 CT scans of patients undergoing UKA?.
        J Arthroplasty. 2014; 29: 1677-1680
        • Karimi E.
        • Norouzian M.
        • Birjandinejad A.
        • Zandi R.
        • Makhmalbaf H.
        Measurement of posterior tibial slope using magnetic resonance imaging.
        Arch Bone Jt Surg. 2017; 5: 435-439
        • Yoo J.H.
        • Chang C.B.
        • Shin K.S.
        • Seong S.C.
        • Kim T.K.
        Anatomical references to assess the posterior tibial slope in total knee arthroplasty: A comparison of 5 anatomical axes.
        J Arthroplasty. 2008; 23: 586-592
        • Faschingbauer M.
        • Sgroi M.
        • Juchems M.
        • Reichel H.
        • Kappe T.
        Can the tibial slope be measured on lateral knee radiographs?.
        Knee Surg Sport Traumatol Arthrosc. 2014; 22: 3163-3167
        • Utzschneider S.
        • Goettinger M.
        • Weber P.
        • et al.
        Development and validation of a new method for the radiologic measurement of the tibial slope.
        Knee Surg Sport Traumatol Arthrosc. 2011; 19: 1643-1648
        • Bisicchia S.
        • Scordo G.M.
        • Prins J.
        • Tudisco C.
        Do ethnicity and gender influence posterior tibial slope?.
        J Orthop Traumatol. 2017; 18: 319-324
        • Fleiss J.L.
        • Chilton N.W.
        • Park M.H.
        Inter- and intra-examiner variability in scoring supragingival plaque: II. Statistical analysis.
        Pharmacol Ther Dent. 1980; 5: 5-9
        • Cicchetti D.V.
        Guidelines, criteria, and rules of thumb for evaluating normed and standardized assessment instruments in psychology.
        Psychol Assess. 1993; 6: 284-290
        • DePhillipo N.N.
        • Kennedy M.I.
        • Dekker T.J.
        • Aman Z.S.
        • Grantham W.J.
        • LaPrade R.F.
        Anterior closing wedge proximal tibial osteotomy for slope correction in failed ACL reconstructions.
        Arthrosc Tech. 2019; 8: e451-e457
        • Sonnery-Cottet B.
        • Mogos S.
        • Thaunat M.
        • et al.
        Proximal tibial anterior closing wedge osteotomy in repeat revision of anterior cruciate ligament reconstruction.
        Am J Sports Med. 2014; 42: 1873-1880
        • Julliard R.
        • Genin P.
        • Weil G.
        • Palmkrantz P.
        La pente tibiale fonctionnelle médiane. Principe. Technique de mesure. Valeur. Intérêt [The median functional slope of the tibia. Principle. Technique of measurement. Value. Interest].
        Rev Chir Orthop Reparatrice Appar Mot. 1993; 79 ([in French]): 625-634
        • Mesquita Queiros C.
        • Abreu G.
        • Moura J.L.
        • et al.
        Anterior closing-wedge osteotomy for posterior slope correction with tibial tubercle preservation.
        Arthrosc Tech. 2019; 8: e1105-e1109
        • Hudek R.
        • Schmutz S.
        • Regenfelder F.
        • Fuchs B.
        • Koch P.P.
        Novel measurement technique of the tibial slope on conventional MRI.
        Clin Orthop Relat Res. 2009; 467: 2066-2072
        • Müller W.
        • Kentsch A.
        • Schäfer N.
        The elastic high tibia valgus osteotomy in the varus deformity.
        Oper Tech Sports Med. 2000; 8: 19-26
        • Schaefer T.K.
        • Majewski M.
        • Hirschmann M.T.
        • Friederich N.F.
        Comparison of sagittal and frontal plane alignment after open- and closed-wedge osteotomy: A matched-pair analysis.
        J Int Med Res. 2008; 36: 1085-1093
        • Medda S.
        • Kundu R.
        • Sengupta S.
        • Pal A.
        Anatomical variation of posterior slope of tibial plateau in adult Eastern Indian population.
        Indian J Orthop. 2017; 51: 69
        • Napier R.J.
        • Garcia E.
        • Devitt B.M.
        • Feller J.A.
        • Webster K.E.
        Increased radiographic posterior tibial slope is associated with subsequent injury following revision anterior cruciate ligament reconstruction.
        Orthop J Sport Med. 2019; 7 (232596711987937)
        • Dejour H.
        • Bonnin M.
        Tibial translation after anterior cruciate ligament rupture: Two radiological tests compared.
        J Bone Joint Surg Br. 1994; 76: 745-749
        • Samuelsen B.T.
        • Aman Z.S.
        • Kennedy M.I.
        • et al.
        Posterior medial meniscus root tears potentiate the effect of increased tibial slope on anterior cruciate ligament graft forces.
        Am J Sports Med. 2020; 48: 334-340
        • Green D.W.
        • Sidharthan S.
        • Schlichte L.M.
        • Aitchison A.H.
        • Mintz D.N.
        Increased posterior tibial slope in patients with Osgood-Schlatter disease: A new association.
        Am J Sports Med. 2020; 48: 642-646