Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts 250


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2014  |  Volume : 5  |  Issue : 2  |  Page : 149-151

Role of palmaris longus as a contributing factor in Carpal Tunnel Syndrome-Ultrasonographic evaluation of Median Nerve and Carpal canal diameter


Department of Orthopaedics, Kasturba Medical College, Manipal University, Manipal, Karnataka, India

Date of Web Publication1-Jul-2014

Correspondence Address:
Babul Reddy
Department of Orthopaedics, Kasturba Medical College, Manipal University, Manipal - 576 104, Karnataka
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0975-9727.135750

Rights and Permissions
  Abstract 

Purpose: To assess the diameter of Carpal tunnel (CT) and the Median Nerve (MN) in individuals with unilateral absence of Palmaris longus (PL) and compare it with the side with presence of Palmaris longus. Materials and Methods: Volunteers (students in the age group of 18-20 years) from a medical college were enrolled over a 2-month period, October to November 2007. Twenty-five subjects with unilateral absence of PL were selected for the study. We used the wrists with PL agenesis as cases and the contra lateral side with PL as controls. Anteroposterior (AP) and transverse diameters of carpal canal and MN were measured at both proximal (pisiform) level and distal (hook of the hamate) level with wrist in neutral position. Results: Significant differences were noted in the dimensions of Carpal canal and MN on the sides with PL as compared to the sides with PL agenesis. The difference in the CT AP diameter was very highly significant at proximal and distal level (P < 0.01) whereas the transverse diameter was significantly different at both the levels. The difference in MN AP diameter was highly significant at distal level. The MN transverse diameter was significantly different at both the levels. Conclusion: In our study we found that the PL tendon is independently associated with decreased CT and MN dimensions (AP > transverse). This study supports the previously done studies on the association between the Carpal Tunnel Syndrome (CTS) and presence of PL tendon.

Keywords: CTS, PL, USG, MN


How to cite this article:
Kamath JB, Reddy B, Jayasheelan N, Savur AD. Role of palmaris longus as a contributing factor in Carpal Tunnel Syndrome-Ultrasonographic evaluation of Median Nerve and Carpal canal diameter. Muller J Med Sci Res 2014;5:149-51

How to cite this URL:
Kamath JB, Reddy B, Jayasheelan N, Savur AD. Role of palmaris longus as a contributing factor in Carpal Tunnel Syndrome-Ultrasonographic evaluation of Median Nerve and Carpal canal diameter. Muller J Med Sci Res [serial online] 2014 [cited 2021 Sep 28];5:149-51. Available from: https://www.mjmsr.net/text.asp?2014/5/2/149/135750


  Introduction Top


Intracarpal canal pressure has been measured in the past and found to be higher in individuals with Carpal Tunnel Syndrome (CTS). [1],[2] Whereas intracarpal canal pressure found to increase after flexor tendon loading is Palmaris longus (PL) which produces increase in pressure more than any other tendon, especially beyond 20° of wrist extension. [3],[4]

G R Keese et al., in their study found that percentage of agenesis of PL was much less in patients with CTS as compared to those without CTS. [5] Many authors have shown that muscle activity and the wrist posture predictably influences the hydrostatic pressure in the carpal tunnel (CT). [2],[3],[4] But the evaluation of PL in normal subjects may be of baseline CT pressure in patients with CTS.

This case-control study was aimed to study and compare the dimensions of carpal canal and Median Nerve (MN) using ultrasonography, in subjects with unilateral absence of PL. The contra lateral wrists with PL of the same individuals were taken as the control. We found this was an effective way to assess the effect of PL on the morphology of carpal canal and MN.


  Materials and Methods Top


A case-control study is performed by taking volunteers (students in the age group of 18-20 years) from a medical college enrolling over a 2-month period, October to November 2007 after obtaining informed consent. Twenty-five subjects with unilateral absence of PL were selected for the study. We used the wrists with PL as cases and the contra lateral side with PL agenesis as controls. Subjects with history of wrist pain, paraesthesia, or tingling numbness of hand, trauma or earlier surgeries of wrist joint and bilateral presence or absence of PL were excluded from the study.

All the participants were briefed about the non-invasive nature of the ultrasound and were allowed to participate in the study on their will. All the subjects were clinically examined for the presence or absence of PL tendon by visualising and palpating the tendon immediately - ulnar to the flexor carpi radialis tendon.

We used 10 MHz transducer ultrasonogram to assess the dimensions of the carpal canal and MN. The evaluation was done by the same experienced consultant throughout the study, to reduce the inter-observer error. Intra-observer variation was eliminated by blinding the radiologist about the purpose of the study. Anteroposterior (AP) and transverse diameters of carpal canal and MN were measured at both proximal (pisiform) level and distal (hook of the hamate) level with wrist in neutral position. Measurements with wrist in flexion and extension were not done as there was mismatch between the probe size and the difficulty to measure in flexion.

The distribution of the population was statistically verified using student's unpaired t test. Statistical significance was determined at P value < 0.05.

P < 0.01 - highly significant

P < 0.001 - very highly significant

P > 0.05 - not significant


  Results Top


The measurements of carpal canal and MN at both levels on both wrists are given below [Table 1],[Table 2],[Table 3] and [Table 4].
Table 1: Median nerve diameter in anteroposterior dimension

Click here to view
Table 2: Median nerve diameter in tranverse dimension

Click here to view
Table 3: Carpal Tunnel diameter in anteroposteriordimension

Click here to view
Table 4: Carpal Tunnel diameter in transverse dimension

Click here to view


One-hundred-and-eighty-six students were screened for this study and twenty-nine subjects satisfied the initial enrolment criteria. Four were excluded due to the symptoms of pain around the wrist. Rest of the twenty-five volunteers participated in the study. The CT and MN diameter (AP &transverse) on one side with PL present (PL+) was compared to the other side without PL (PL−) using as the control. The P value calculated using independent student's T test as mentioned previously.

The difference in the CT AP diameter was very highly significant at proximal and distal level (P < 0.01) whereas the transverse diameter was significantly different at both the levels. The difference in MN AP diameter was highly significant at distal level. The MN transverse diameter was significantly different at both the levels.

This study revealed significant differences in the diameters of CT as well as MN in persons with the presence of PL as compared to those with PL agenesis.


  Discussion Top


To the best of our knowledge there has been no study of this nature in the past where ultrasonography is used for the evaluation of CT and MN in subjects with unilateral PL agenesis.

The PL is a wrist flexor that becomes confluent with the palmar aponeurosis at the wrist. PL may influence the shape and volume of CT. [3] The PL insertion into palmar fascia overlying the CT probably exerts a pressure effect on the CT, predisposing to development of CTS. PL agenesis is considered to be a dominantly inherited trait. We concur with the study 'The clinical significance of PL tendon in pathophysiology of CTS' by Keese et al. [5]

In our study we found that the PL tendon is independently associated with decreased CT and MN dimensions (AP > transverse). This study supports the previously done studies on the association between the CTS and presence of PL tendon. However, this study was done on normal individuals with no symptoms of CTS. Further studies are required to consider the surgical option like tenotomy of PL tendon to prevent CTS in individuals with subclinical CTS. In other words when NCV studies show the evidence of early or subclinical CTS,a minor procedure like PL tenotomy may prevent them from becoming symptomatic. But this procedure is to be done with caution as PL is a precious source for future tendon graft hence it is very important to preserve this tendon as far as possible.

 
  References Top

1.Buchberger W, Judmaier W, Birbamer G, Lener M, Schmidauer C. Carpal tunnel syndrome: Diagnosis with high-resolution sonography. AJR Am J Roentgenol 1992;159:793-8.  Back to cited text no. 1
    
2.Chen P, Maklad N, Redwine M, Zelitt D. Dynamic high-resolution sonography of the carpal tunnel. AJR Am J Roentgenol 1997;168:533-7.  Back to cited text no. 2
    
3.Yoshioka S, Okuda Y, Tamai K, Hirasawa Y, Koda Y. Changes in carpal tunnel shape during wrist joint motion. MRI evaluation of normal volunteers. J Hand Surg Br 1993;18:620-3.  Back to cited text no. 3
    
4.Nakamichi K, Tachibana S. The use of ultrasonography in detection of synovitis in carpal tunnel syndrome. J Hand Surg Br 1993;18:176-9.  Back to cited text no. 4
    
5.Keese GR, Wongaworawat MD, Frykman G. The clinical significance of palmaris longus tendon in the pathophysiology of carpal tunnel syndrome. J Hand Surg Br 2006;31:657-60.  Back to cited text no. 5
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Discussion
References
Article Tables

 Article Access Statistics
    Viewed2929    
    Printed75    
    Emailed0    
    PDF Downloaded241    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]