scholarly journals Carpal Tunnel Expansion by Palmarly Directed Forces to the Transverse Carpal Ligament

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
Zong-Ming Li ◽  
Jie Tang ◽  
Matthew Chakan ◽  
Rodrigo Kaz
Keyword(s):  
Carpal Tunnel ◽  
Geometrical Model ◽  
Transverse Carpal Ligament ◽  
Arch Height ◽  
Cross Sectional ◽  
Arch Width ◽  
Force Application ◽  
Fresh Frozen ◽  
Applied Forces ◽  
Insertion Sites

This study investigated the expansion of the carpal tunnel resulting from the application of palmarly directed forces to the transverse carpal ligament (TCL) from inside the carpal tunnel. Ten fresh-frozen cadaveric hands were dissected to evacuate the carpal tunnel, and thus to expose the TCL. A custom lever device was built to apply forces, ranging from 10 N to 200 N, to the TCL. Without force application, the carpal tunnel area was 148.4±36.8 mm2. The force application caused the TCL to form arches with an increase in cross-sectional areas of 33.3±5.6 mm2 at 10 N and 48.7±11.4 mm2 at 200 N, representing respective increases of 22.4% and 32.8% relative to the initial carpal tunnel area. The TCL length remained constant under the applied forces. It was found that the TCL arch formation was due to the narrowing of the arch width, which resulted from the migration of the bony insertion sites of the TCL. A geometrical model of the carpal tunnel was then developed to elucidate the relationships among the arch width, TCL length, arch height, and arch area. The model illustrated the effectiveness of carpal tunnel expansion by TCL elongation or arch width narrowing.

Experimentally and Theoretically Narrowing Carpal Arch Width to Increase the Area Formed by the Transverse Carpal Ligament

2011 ◽  
Author(s):  
Suk H. Yu ◽  
Tracy A. Mondello ◽  
Zong-Ming Li
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Median Nerve ◽  
Carpal Tunnel ◽  
Transverse Carpal Ligament ◽  
Cross Sectional ◽  
Arch Width ◽  
Endoscopic Release ◽  
Volar Aspect ◽  
Tunnel Syndrome

Carpal tunnel syndrome is conventionally treated by open and endoscopic release surgeries in which transecting the transverse carpal ligament (TCL) relieves mechanical insults around the median nerve. The TCL release surgeries yield an increase in the tunnel cross-sectional area particularly within the volar aspect of the tunnel, the arch area, where the median nerve is located. As a result of increased arch area, post-operative follow-up studies using MRI confirmed a significant volar migration of the median nerve [1]. However, transecting the TCL compromises critical biomechanical roles of the carpal tunnel [2], and therefore, it is imperative to investigate an alternative method for treating carpal tunnel syndrome patients while preserving the TCL. Li et al. suggested that increasing the TCL length and narrowing the carpal arch width (CAW) as potential alternatives for increasing the arch area [3]. However, the data from their application of palmarly directed forces to the TCL from inside of the tunnel showed that the TCL length remained relatively constant while the carpal bones were mobilized to increase the arch area [3]. The purpose of this study was to investigate the relationship between CAW narrowing and the TCL-formed arch area by experimental and geometrical modeling.

Stiffness of the Transverse Carpal Ligament Under the Influence of Collagenase

2011 ◽  
Author(s):  
Ryan K. Prantil ◽  
Tracy A. Mondello ◽  
Suk H. Yu ◽  
Khurram Pervaiz ◽  
Savio L-Y. Woo ◽  
...  
Keyword(s):  
Carpal Tunnel ◽  
Carpal Tunnel Release ◽  
Geometrical Model ◽  
Sectional Area ◽  
Transverse Carpal Ligament ◽  
Cross Sectional ◽  
Peptide Bonds ◽  
Stiffness Reduction ◽  
Operative Complications ◽  
Tunnel Syndrome

Forming the palmar roof of the carpal tunnel, the transverse carpal ligament (TCL) continues to be the surgical target for carpal tunnel release which aims to relieve the symptoms of patients with carpal tunnel syndrome. However, the surgical procedures may cause several biomechanical and anatomical problems for the carpal tunnel [1]. Therefore, an alternative, aimed at preserving the TCL, might alleviate patients’ post-operative complications. Using a geometrical model, Li et al. showed that the cross-sectional area of the carpal tunnel can be effectively increased by TCL elongation [2]. Theoretically, stiffness reduction could facilitate a ligament’s capability to elongate. Past studies have shown that the utilization of the collagenase enzyme altered the mechanical properties of a soft tissue [3, 4]. It also has been used to treat Dupuytren’s Contracture [5] because collagenase breaks the peptide bonds within collagen fibers [6]. The usage of collagenase could effectively reduce the stiffness of the TCL allowing for the ligament to elongate and for the median nerve to decompress. Thus, the purpose of our study is to determine the effect of collagenase on the stiffness of the TCL. We hypothesize that the stiffness of the ligament will progressively decrease due to the enzymatic effect of collagenase.

scholarly journals The Effect of an Open Carpal Tunnel Release on Thumb CMC Biomechanics

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Marc A. Tanner ◽  
Bryan P. Conrad ◽  
Paul C. Dell ◽  
Thomas W. Wright
Keyword(s):  
Carpal Tunnel ◽  
Soft Tissues ◽  
Carpal Tunnel Release ◽  
Transverse Carpal Ligament ◽  
Before And After ◽  
Fresh Frozen ◽  
Rigid Body Mechanics ◽  
Thumb Carpometacarpal ◽  
Open Carpal Tunnel Release ◽  
Cmc Joint

Purpose. We have observed worsening thumb pain following carpal tunnel release (CTR) in some patients. Our purpose was to determine the effect of open CTR on thumb carpometacarpal (CMC) biomechanics.Methods. Five fresh-frozen cadaver arms with intact soft tissues were used. Each specimen was secured to a jig which fixed the forearm at 45° supination, and the wrist at 20° dorsiflexion, with thumb pointing up. The thumb was axially loaded with a force of 130 N. We measured 3D translation and rotation of the trapezium, radius, and first metacarpal, before and after open CTR. Motion between radius and first metacarpal, radius and trapezium, and first metacarpal and trapezium during loading was calculated using rigid body mechanics. Overall stiffness of each specimen was determined.Results. Total construct stiffness following CTR was reduced in all specimens but not significantly. No significant changes were found in adduction, pronation, or dorsiflexion of the trapezium with respect to radius after open CTR. Motion between radius and first metacarpal, between radius and trapezium, or between first metacarpal and trapezium after open CTR was not decreased significantly.Conclusion. From this data, we cannot determine if releasing the transverse carpal ligament alters kinematics of the CMC joint.

scholarly journals Narrowing carpal arch width to increase cross-sectional area of carpal tunnel — a cadaveric study

2013 ◽  
Vol 28 (4) ◽  
pp. 402-407 ◽  
Author(s):  
Zong-Ming Li ◽  
Joseph N. Gabra ◽  
Tamara L. Marquardt ◽  
Dong Hee Kim
Keyword(s):  
Carpal Tunnel ◽  
Cross Sectional Area ◽  
Cadaveric Study ◽  
Sectional Area ◽  
Cross Sectional ◽  
Arch Width

Thenar and Hypothenar Muscle Coverage on the Transverse Carpal Ligament

2021 ◽  
Author(s):  
Farah Alsafar ◽  
Zong-Ming Li
Keyword(s):  
Carpal Tunnel ◽  
Carpal Tunnel Release ◽  
Transverse Carpal Ligament ◽  
Thenar Muscle ◽  
Cross Sectional ◽  
Tunnel Syndrome ◽  
Carpal Tunnel Release Surgery ◽  
Automated Algorithms ◽  
Hypothenar Muscle

Abstract Background The purpose of the study was to examine the coverage of thenar and hypothenar muscles on the transverse carpal ligament (TCL) in the radioulnar direction through in vivo ultrasound imaging of the carpal tunnel. We hypothesized that the TCL distance covered by the thenar muscle would be greater than that by the hypothenar muscle, and that total muscle coverage on the TCL would be greater than the TCL-alone region. Methods Ultrasound videos of human wrist were collected on 20 healthy subjects. Automated algorithms were used to extract the distal cross-sectional image of the trapezium-hamate level. Manual tracing of the anatomical features was conducted. Results Thenar muscles covered a significantly larger distance (11.9 ± 1.8 mm) as compared with hypothenar muscles (1.7 ± 0.8 mm) (p < 0.001). The TCL covered by thenar and hypothenar muscles was greater than the TCL-alone length (p < 0.001). The thenar and hypothenar muscle coverage on the TCL, as normalized to the total TCL length, was 61.0 ± 7.5%. Conclusions More than 50% of the TCL at the distal carpal tunnel is covered by thenar and hypothenar muscles. Knowledge of muscular attachments to the TCL improves our understanding of carpal tunnel syndrome etiology and can guide carpal tunnel release surgery.

Carpal Arch Changes in Response to Thenar Muscle Loading

2021 ◽  
Author(s):  
Hui Zhang ◽  
Jeremy Loss ◽  
Zong-Ming Li
Keyword(s):  
Cross Section ◽  
Carpal Tunnel ◽  
Loading Condition ◽  
Ultrasound Images ◽  
Transverse Carpal Ligament ◽  
Arch Height ◽  
Abductor Pollicis Brevis ◽  
Thenar Muscle ◽  
Morphometric Analyses ◽  
Muscle Loading

Abstract This study investigated the biomechanical effects of thenar muscles (abductor pollicis brevis, APB; superficial head of flexor pollicis brevis, sFPB; opponens pollicis, OPP) on the transverse carpal ligament formed carpal arch under force application by individual or combined muscles (APB, sFPB, OPP, APB-sFPB, sFPB-OPP, APB-OPP, and APB-sFPB-OPP). In ten cadaveric hands, thenar muscles were loaded under 15% of their respective maximal force capacity, and ultrasound images of the cross section of the distal carpal tunnel were collected for morphometric analyses of the carpal arch. The carpal arch height and area were significantly dependent on the loading condition (p &lt; 0.01), muscle combination (p &lt; 0.05), and their interaction (p &lt; 0.01). The changes to arch height and area were significantly dependent on the muscle combinations (p = 0.001 and p &lt; 0.001, respectively). The arch height and area increased under the loading combinations of APB, OPP, APB-sFPB, APB-OPP or APB-sFPB-OPP (p &lt; 0.05), but not under the combinations of sFPB (p = 0.893) or sFPB-OPP (p = 0.338). The carpal arch change under the APB-sFPB-OPP or APB-OPP loading was greater than that under the loading of APB-sFPB (p &lt; 0.001). This study demonstrated that thenar muscle forces exert biomechanical effects on the transverse carpal ligament to increase carpal arch height and area, and these increases were different for individual muscles and their combinations.

scholarly journals Biomechanical interaction between the transverse carpal ligament and the thenar muscles

2013 ◽  
Vol 114 (2) ◽  
pp. 225-229 ◽  
Author(s):  
Zhilei Liu Shen ◽  
Zong-Ming Li
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Carpal Tunnel ◽  
Morphological Changes ◽  
Maximum Voluntary Contraction ◽  
Muscle Contractions ◽  
Transverse Carpal Ligament ◽  
Arch Height ◽  
Thenar Muscle ◽  
Pinch Force ◽  
Tunnel Syndrome

The transverse carpal ligament (TCL) serves as the origin of the thenar muscles and is integral to thenar muscle contraction anatomically and biomechanically. TCL hypertrophy has been observed in patients with carpal tunnel syndrome and is potentially caused by repetitive hand use. The purpose of this study was to investigate the biomechanical interaction between the TCL and the thenar muscles. Specifically, the morphological changes of the carpal arch, formed by the TCL, in response to thenar muscle contractions were examined during isometric tip pinch between the thumb and index finger. Ultrasound videos of the carpal tunnel were recorded from 13 healthy subjects and were synchronized with the forces measured by a pinch dynamometer. The thenar muscles' ulnar point, trapezium, and hamate were tracked by a pattern-matching program. The pinch force significantly affected the carpal arch height, width, and area ( P < 0.005). As the pinch force increased from 0 to 100% maximum voluntary contraction force, the carpal arch height increased from 1.8 ± 1.0 to 2.3 ± 1.3 mm, the carpal arch width decreased from 23.9 ± 2.4 to 23.1 ± 2.4 mm, and the carpal arch area increased from 22.2 ± 13.6 to 27.3 ± 16.3 mm2. The TCL was pulled volarly during thenar muscle contractions, providing evidence for the biomechanical interaction between the ligament and muscles. Repetitive biomechanical stimulation on the TCL from thenar muscle contractions could lead to tissue remodeling and then TCL hypertrophy. This study sheds light on the potential cause of TCL hypertrophy, which may be an etiological factor for carpal tunnel syndrome.

Palmar Musculature: Does It Affect the Development of Carpal Tunnel Syndrome? A Pilot Study

2021 ◽  
Author(s):  
Trevor Simcox ◽  
Lauren Seo ◽  
Kevin Dunham ◽  
Shengnan Huang ◽  
Catherine Petchprapa ◽  
...  
Keyword(s):  
Carpal Tunnel Syndrome ◽  
Correlation Coefficient ◽  
Carpal Tunnel ◽  
Case Control Study ◽  
Anatomical Variation ◽  
Case Control ◽  
Transverse Carpal Ligament ◽  
Large Variability ◽  
Tunnel Syndrome ◽  
Control Study

Abstract Background The etiology of carpal tunnel syndrome (CTS) is multifactorial. Static mechanical characteristics of CTS have been described, but dynamic (muscular) parameters remain obscure. We believe that musculature overlying the transverse carpal ligament may have an effect on carpal tunnel pressure and may explain the prevalence of CTS in manual workers. Questions/Purposes To utilize magnetic resonance imaging (MRI) imaging to estimate the amount of muscle crossing the area of the carpal tunnel and to compare these MRI measurements in patients with and without documented CTS. Methods A case–control study of wrist MRI scans between January 1, 2018, and December 1, 2019, was performed. Patients with a diagnosis of CTS were matched by age and gender with controls without a diagnosis of CTS. Axial MRI cuts at the level of the hook of the hamate were used to measure the thenar and hypothenar muscle depth overlying the carpal tunnel. Muscle depth was quantified in millimeters at three points: midcapitate, capitate–hamate border, capitate–trapezoid border. Average depth was calculated by dividing the cross-sectional area (CSA) by the transverse carpal ligament width. Statistical analysis included Student's t-test, chi-square test, and Pearson's correlation coefficient calculation. Results A total of 21 cases and 21 controls met the inclusion criteria for the study. There were no significant differences in demographics between case and control groups. The location and depth of the musculature crossing the carpal tunnel were highly variable in all areas evaluated. A significantly positive correlation was found between proximal median nerve CSA and muscle depth in the capitate–hamate area (correlation coefficient = 0.375; p = 0.014). CSA was not significantly associated with chart documented CTS. Conclusions We found large variability in our measurements. This likely reflects true anatomical variation. The significance of our findings depends on the location of the muscles and the line of pull and their effect on the mechanics of the transverse carpal ligament. Future research will focus on refining measurement methodology and understanding the mechanical effect of the muscular structure and insertions on carpal tunnel pressure. Level of Evidence This is a Level 3, case–control study.

Dental Arch Width in Children and Relationship to their Oral Habits

2019 ◽  
pp. 6-11
Author(s):  
Kohinur Akther ◽  
Md Zakir Hossain
Keyword(s):  
School Children ◽  
Cross Sectional Study ◽  
Primary School Children ◽  
Dental Arch ◽  
Sectional Study ◽  
Cross Sectional ◽  
Oral Habits ◽  
Arch Width ◽  
Bangladeshi Population ◽  
Dental Arch Width

Aim: Objectives: To analyze variations in dental arch width in relation to oral habits.   Materials and Methods : Cross sectional  study was carried out Department of Orthodontics & Dentofacial Orthopedics of Dhaka Dental College & Hospital, Dhaka with a total number of 600 primary school children of 3-6 years ages of Bangladeshi population. Results: This study was a cross sectional study conducted among the 600 children with 3-6 years old prima- ry school children of Bangladeshi population. According to present study, bottle feeding causes significant reduction in maxillary intercanine width and mouth breathers show significant reduction of both arches. Conclusion: It was observed that the children who had used a bottle had a significant reduction in maxillary intercanine width. Breathing through mouth appeared to be associated with a reduction in the size of both arches. This was more significant in the maxillary intercanine , mandibular  intercanine and mandibular molar widths. Therefore to prevent malocclusions, the public should be informed of the harm caused by certain oral habits, the benefits of breast-feeding, and the need to correct bad habits at early life. Ban J Orthod & Dentofac Orthop, April 2016; Vol-7 (1-2), P.6-11

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