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1.
Clin Orthop Relat Res ; 475(4): 1265-1271, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28050816

ABSTRACT

BACKGROUND: Voluntary knuckle cracking is a common habit, with a reported prevalence of 25% to 45%. Habitual knuckle cracking also is a frequent source of questions for physicians, and the largest study to date reported an association with functional hand impairments. QUESTIONS/PURPOSES: (1) When compared with subjects who are not habitual knuckle crackers, do habitual knuckle crackers have greater QuickDASH scores, swelling, weakness, joint laxity, or ROM? (2) In subjects who crack their knuckles, does cracking immediately increase ROM? (3) What are the characteristic sonographic findings in joints that crack? METHODS: A prospective, institutional review board-approved study was performed on 400 metacarpophalangeal joints (MPJs) in 40 asymptomatic adult subjects. Of those, 30 subjects had a history of habitual knuckle cracking (defined as daily voluntary popping of MPJs). Clinical history provided by all subjects included a standardized QuickDASH questionnaire. Physical examination was performed by two orthopaedic surgeons (blinded to subjects' knuckle-cracking history and sonographic outcomes). The physical examination included evaluation for swelling, grip strength, and ROM before and after attempted knuckle cracking. Sonographic examination was conducted by one sonographer, with static and real-time cine images recorded before, during, and after MPJ distraction was performed by the subjects. Two musculoskeletal radiologists (blinded to subjects' knuckle-cracking history) interpreted the images for a definite hyperechoic focus during and after MPJ distraction; this was compared against the reference standard of an audible "crack" during joint distraction. RESULTS: Comparing subjects with knuckle cracking with those who did not crack their knuckles, there was no differences in QuickDASH scores (knuckle crackers, 3.7 ± 5.2; nonknuckle crackers, 3.2 ± 6.3; mean difference, 0.6; 95% CI, -3.5 to 4.6; p = 0.786), laxity (knuckle crackers, 2.0 ± 1.8; nonknuckle crackers, 0.3 ± 0.7; mean difference, 1.7; 95% CI, 0.5-2.9; p = 0.191), and grip strength (preultrasound, right hand, p = 0.499, left hand p = 0.575; postultrasound, right hand p = 0.777, left hand p = 0.424); ROM comparisons between subjects with a history of habitual knuckle cracking versus subjects without such a history only yielded increased ROM in joints that cracked during manipulation (knuckle cracking, 143.8° ± 26.5°; nonknuckle cracking, 134.9° ± 28.6°; mean difference, 9.0°; 95% CI, 2.9°-15.1°; p = 0.004). Swelling was not observed in any subjects, including when comparing MPJs before versus after distraction maneuvers that resulted in audible cracks. Immediately after a documented crack, there were greater ranges of motion with active flexion (preultrasound, 85.7° ± 12.4°; postultrasound, 88.6° ± 11.6°; mean difference, -2.9°; 95% CI, -5.1° to -0.8°; p = 0.009), passive flexion (preultrasound, 96.1° ± 12.4°; postultrasound, 100.3° ± 10.4°; mean difference, -4.3°; 95% CI, -6.2° to -2.3°; p < 0.001), passive extension (preultrasound, 41.8° ± 18.1°; postultrasound, 45.2° ± 17.6°; mean difference, -3.5°; 95% CI, -6.9° to -0.1°; p = 0.046), and passive total ROM (preultrasound, 137.8° ± 24.8°; postultrasound, 145.6° ± 23.1°; mean difference, -7.7°; 95% CI, -11.7° to -3.8°; p < 0.001). The characteristic sonographic finding observed during cracking events is an echogenic focus that appears de novo dynamically in the joint during distraction. CONCLUSIONS: We found no evidence of immediate adverse physical examination findings after knuckle cracking. However, we did find a small increase in ROM among joints that cracked compared with those that did not. Future studies should examine if there are any long-term beneficial and adverse clinical outcomes associated with habitual knuckle cracking. LEVEL OF EVIDENCE: Level I, prognostic study.


Subject(s)
Habits , Joint Instability/diagnostic imaging , Joint Instability/physiopathology , Metacarpophalangeal Joint/diagnostic imaging , Metacarpophalangeal Joint/physiopathology , Noise , Physical Examination , Ultrasonography , Adult , Biomechanical Phenomena , Disability Evaluation , Female , Hand Strength , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Range of Motion, Articular , Young Adult
2.
Magn Reson Imaging Clin N Am ; 23(3): 393-403, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26216770

ABSTRACT

MR imaging has emerged as the mainstay in imaging internal derangement of the soft tissues of the musculoskeletal system largely because of superior contrast resolution. The complex geometry and diminutive size of the triangular fibrocartilage complex (TFCC) and its constituent structures can make optimal imaging of the TFCC challenging; therefore, production of clinically useful images requires careful optimization of image acquisition parameters. This article provides a foundation for advanced TFCC imaging including factors to optimize magnetic resonance images, arthrography, detailed anatomy, and classification of injury. In addition, clinical presentations and treatments for TFCC injury are briefly considered.


Subject(s)
Magnetic Resonance Imaging/methods , Triangular Fibrocartilage/injuries , Wrist Injuries/diagnosis , Wrist Joint/anatomy & histology , Wrist Joint/pathology , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional , Magnetic Resonance Imaging/instrumentation
3.
Bioorg Med Chem Lett ; 23(16): 4674-9, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23856050

ABSTRACT

The structure activity relationship of the prime region of conformationally restricted hydroxyethylamine (HEA) BACE inhibitors is described. Variation of the P1' region provided selectivity over Cat-D with a series of 2,2-dioxo-isothiochromanes and optimization of the P2' substituent of chromane-HEA(s) with polar substituents provided improvements in the compound's in vitro permeability. Significant potency gains were observed with small aliphatic substituents such as methyl, n-propyl, and cyclopropyl when placed at the C-2 position of the chromane.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Chromans/chemistry , Drug Design , Enzyme Inhibitors/chemical synthesis , Binding Sites , Cells, Cultured , Ethylamines/chemical synthesis , Ethylamines/chemistry , Ethylamines/pharmacology , Inhibitory Concentration 50 , Models, Molecular , Structure-Activity Relationship
4.
Bioorg Med Chem Lett ; 21(12): 3726-9, 2011 Jun 15.
Article in English | MEDLINE | ID: mdl-21570836

ABSTRACT

In this Letter, we describe the evolution of selective JNK3 inhibitors from 1, that routinely exhibit >10-fold selectivity over JNK1 and >1000-fold selectivity over related MAPKs. Strong SAR was found for substitution of the naphthalene ring, as well as for inhibitors adopting different central scaffolds. Significant potency gains were appreciated by inverting the polarity of the thione of the parent triazolothione 1, resulting in potent compounds with attractive pharmacokinetic profiles.


Subject(s)
Enzyme Inhibitors/pharmacology , Mitogen-Activated Protein Kinase 10/antagonists & inhibitors , Naphthalenes/chemical synthesis , Thiones/chemical synthesis , Animals , Cells, Cultured , Enzyme Activation/drug effects , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Mice , Microsomes, Liver/enzymology , Molecular Structure , Naphthalenes/chemistry , Naphthalenes/pharmacology , Solubility , Structure-Activity Relationship , Thiones/chemistry , Thiones/pharmacology
5.
Bioorg Med Chem Lett ; 21(1): 315-9, 2011 Jan 01.
Article in English | MEDLINE | ID: mdl-21112785

ABSTRACT

In this Letter, we describe the discovery of selective JNK2 and JNK3 inhibitors, such as 10, that routinely exhibit >10-fold selectivity over JNK1 and >1000-fold selectivity over related MAPKs, p38α and ERK2. Substitution of the naphthalene ring affords an isoform selective JNK3 inhibitor, 30, with approximately 10-fold selectivity over both JNK1 and JNK2. A naphthalene ring penetrates deep into the selectivity pocket accounting for the differentiation amongst the kinases. Interestingly, the gatekeeper Met146 sulfide interacts with the naphthalene ring in a sulfur-π stacking interaction. Compound 38 ameliorates neurotoxicity induced by amyloid-ß in human cortical neurons. Lastly, we demonstrate how to install propitious in vitro CNS-like properties into these selective inhibitors.


Subject(s)
Aminopyridines/chemistry , Mitogen-Activated Protein Kinase 10/antagonists & inhibitors , Mitogen-Activated Protein Kinase 9/antagonists & inhibitors , Neurodegenerative Diseases/drug therapy , Neuroprotective Agents/chemistry , Protein Kinase Inhibitors/chemistry , Triazines/chemistry , Aminopyridines/pharmacokinetics , Aminopyridines/therapeutic use , Animals , Binding Sites , Central Nervous System/metabolism , Computer Simulation , Humans , Mice , Microsomes, Liver/metabolism , Mitogen-Activated Protein Kinase 10/metabolism , Mitogen-Activated Protein Kinase 9/metabolism , Neuroprotective Agents/pharmacokinetics , Neuroprotective Agents/therapeutic use , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/therapeutic use , Structure-Activity Relationship , Triazines/pharmacokinetics , Triazines/therapeutic use
6.
Bioorg Med Chem Lett ; 20(21): 6231-6, 2010 Nov 01.
Article in English | MEDLINE | ID: mdl-20833041

ABSTRACT

In this Letter, we describe our efforts to design HEA BACE-1 inhibitors that are highly permeable coupled with negligible levels of permeability-glycoprotein activity. These efforts culminate in producing 16 which lowers Αß by 28% and 32% in the cortex and CSF, respectively, in the preclinical wild type Hartley guinea pig animal model when dosed orally at 30mpk BID for 2.5days.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Ethylamines/chemical synthesis , Ethylamines/pharmacology , Protease Inhibitors/chemical synthesis , Protease Inhibitors/pharmacology , Alkylation , Alzheimer Disease , Animals , Brain/metabolism , Cell Line , Dogs , Drug Design , Guinea Pigs , Humans , Indicators and Reagents , Protease Inhibitors/pharmacokinetics , Protein Binding , Structure-Activity Relationship
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