title: Preventive lateral ligament tester (PLLT): a novel method to evaluate mechanical properties of lateral ankle joint ligaments in the intact ankle.
abstract: OBJECTIVE
  To construct and evaluate an ankle arthrometer that registers inversion joint deflection at standardized inversion loads and that, moreover, allows conclusions about the mechanical strain of intact ankle joint ligaments at these loads.
  
  
  METHODS
  Twelve healthy ankles and 12 lower limb cadaver specimens were tested in a self-developed measuring device monitoring passive ankle inversion movement (Inv-ROM) at standardized application of inversion loads of 5, 10 and 15 N. To adjust in vivo and in vitro conditions, the muscular inactivity of the evertor muscles was assured by EMG in vivo. Preliminary, test-retest and trial-to-trial reliabilities were tested in vivo. To detect lateral ligament strain, the cadaveric calcaneofibular ligament was instrumented with a buckle transducer. After post-test harvesting of the ligament with its bony attachments, previously obtained resistance strain gauge results were then transferred to tensile loads, mounting the specimens with their buckle transducers into a hydraulic material testing machine.
  
  
  RESULTS
  ICC reliability considering the Inv-ROM and torsional stiffness varied between 0.80 and 0.90. Inv-ROM ranged from 15.3° (±7.3°) at 5 N to 28.3° (±7.6) at 15 N. The different tests revealed a CFL tensile load of 31.9 (±14.0) N at 5 N, 51.0 (±15.8) at 10 N and 75.4 (±21.3) N at 15 N inversion load.
  
  
  CONCLUSIONS
  A highly reliable arthrometer was constructed allowing not only the accurate detection of passive joint deflections at standardized inversion loads but also reveals some objective conclusions of the intact CFL properties in correlation with the individual inversion deflections. The detection of individual joint deflections at predefined loads in correlation with the knowledge of tensile ligament loads in the future could enable more individual preventive measures, e.g., in high-level athletes.
authors: Department of Orthopedic and Sports Trauma Surgery, Sportklinik Stuttgart GmbH, Taubenheimstrasse 8, 70372, Stuttgart, Germany. MonBest@aol.com.
authors: Raymond
authors: R
authors: Best
authors: Department of Orthopedics and Biomechanics, German Sports University Cologne, Cologne, Germany.
authors: Caroline
authors: C
authors: Böhle
authors: Department of Orthopedic and Sports Trauma Surgery, Sportklinik Stuttgart GmbH, Taubenheimstrasse 8, 70372, Stuttgart, Germany.
authors: Frieder
authors: F
authors: Mauch
authors: Department of Orthopedics and Biomechanics, German Sports University Cologne, Cologne, Germany.
authors: Peter G
authors: PG
authors: Brüggemann
mesh_terms: D000328:Adult; D000368:Aged; D000843:Ankle Joint / Q000502:physiology*; D053587:Arthrometry, Articular / Q000295:instrumentation*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D017844:Lateral Ligament, Ankle / Q000502:physiology*; D008297:Male; D015203:Reproducibility of Results; D013180:Sprains and Strains / Q000503:physiopathology; D013718:Tensile Strength / Q000502:physiology
keywords: Ankle ligament; Injury prevention; Inversion injury; Ligament strain