title: Can joint sound assess soft and hard endpoints of the Lachman test?: A preliminary study.
abstract: The Lachman test is considered to be a reliable physical examination for anterior cruciate ligament (ACL) injury. Patients with a damaged ACL demonstrate a soft endpoint feeling. However, examiners judge the soft and hard endpoints subjectively. The purpose of our study was to confirm objective performance of the Lachman test using joint auscultation. Human and porcine knee joints were examined. Knee joint sound during the Lachman test (Lachman sound) was analyzed by fast Fourier transformation. As quantitative indices of Lachman sound, the peak sound as the maximum relative amplitude (acoustic pressure) and its frequency were used. The mean Lachman peak sound for healthy volunteer knees was 86.9 ± 12.9 Hz in frequency and -40 ± 2.5 dB in acoustic pressure. The mean Lachman peak sound for intact porcine knees was 84.1 ± 9.4 Hz and -40.5 ± 1.7 dB. Porcine knees with ACL deficiency had a soft endpoint feeling during the Lachman test. The Lachman peak sounds of porcine knees with ACL deficiency were dispersed into four distinct groups, with center frequencies of around 40, 160, 450, and 1600. The Lachman peak sound was capable of assessing soft and hard endpoints of the Lachman test objectively.
authors.affiliation: Department of Physical Therapy, Faculty of Nursing and Rehabilitation, Konan Women's University, 6-2-23, Morikita-machi, Higashinada-ku, Kobe, Hyogo 658-0001, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Hattori
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840, Shijyo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Munehiro
authors.initials: M
authors.lastname: Ogawa
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840, Shijyo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Department of Physical Therapy, Faculty of Nursing and Rehabilitation, Konan Women's University, 6-2-23, Morikita-machi, Higashinada-ku, Kobe, Hyogo 658-0001, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Matsuya
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840, Shijyo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Kota
authors.initials: K
authors.lastname: Uematsu
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840, Shijyo-cho, Kashihara, Nara 634-8522, Japan.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000818:Animals; D000070598:Anterior Cruciate Ligament Injuries / Q000175:diagnosis* / Q000473:pathology; D001314:Auscultation / Q000379:methods; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D013016:Sound; D013552:Swine
keywords: ACL injury; Lachman test; joint auscultation; joint sound