Different frequency of the absence of the palmaris longus according to assessment methods in a Korean population

Clinical tests for assessing the presence and quality of the palmaris longus tendon: diagnostic accuracy of examination compared with ultrasound

Various clinical tests are used to evaluate the palmaris longus tendon, but their accuracy is unknown. We assessed the accuracy of clinical tests (Schaeffer's, Thompson's, Mishra-I, Mishra-II) against ultrasound as the reference standard. We hypothesized that Schaeffer's was most accurate and that examination can reliably assess the palmaris longus tendon's length. Ninety-six wrists were examined clinically and evaluated with ultrasound by radiologists who were blinded to examination results. We calculated diagnostic accuracy and agreement between length measurements. Sensitivity values were as follows: Schaeffer's 94%, Mishra-I 100%, Mishra-II 100%, Thompson's 72%. Specificity values were as follows: Schaeffer's 94%, Mishra-I 83%, Mishra-II 89%, Thompson's 91%. Intraclass correlation coefficient between palmaris longus tendon length measurement on examination and ultrasound was 0.54. Schaeffer's test accurately detected this tendon with >90% sensitivity and specificity, but clinical examination less reliably measured palmaris longus tendon length. Ultrasound may be a useful adjunct to assess potential graft length preoperatively. Level of evidence: I.

Detection of the palmaris longus tendon: physical examination versus sonography

This study investigated the sensitivity, specificity, and accuracy of physical examination compared with high resolution sonography for the detection of the palmaris longus tendon in 136 wrists. The incidence of tendon absence was 10% by sonography and 14% by physical examination. The sensitivity of the physical examination was 94% and the specificity 86% compared with sonography as the reference standard. Accurate identification of the palmaris longus tendon through physical examination was not influenced by body mass index or wrist circumference. Upon review of the sonography images, none of the palmaris longus tendons missed on physical examination were considered to be adequate for grafting based on expert opinion. While physical exam was 93% accurate for detection of the palmaris longus tendon compared with ultrasound, our study suggests that it is sufficient for detection of those tendons that can be used as donors clinically.

Interobserver and intraobserver reliability of different methods of examination for presence of palmaris longus and examination of fifth superficial flexor function

The palmaris longus is harvested as a tendon graft in various surgical procedures. Several tests are used to assess the presence of palmaris longus tendon. In the present study, we attempted to assess the interobserver and intraobserver reliability of five of the most famous methods and also the examination of fifth superficial flexor function. Two observers, who had been trained on the tests and had practiced them, examined 105 volunteers on two separate occasions and in 1-month interval the results were recorded. The reliability of each method was assessed with Kappa measurement. Kappa ranged from 0.541 (moderate reliability) to 0.813 (almost complete agreement) for palmaris. The highest interobserver and intraobserver reliability and also the best agreement with other tests were of Schaeffer. The lowest kappa was for Thompson and the others have good to excellent reliability. Kappa for interobserver and intraobserver reliability for the fifth flexor were 0.415 and 0.500 (moderate reliability), respectively. The tests that were assessed have good reliability except for Thompson that has a moderate one. It seems that the standard test (Schaeffer) is the best method for the assessment of the absence or presence of palmaris longus. The method used for the evaluation of fifth superficial flexor variations assessment has a moderate interobserver and intraobserver reliability.

Prevalence of Absence of Palmaris Longus and Its Association with Gender, Hand Dominance and Absence of FDS Tendon to Little Finger Among Malay Population

BACKGROUND

Palmaris Longus is being widely used in reconstructive, plastic and cosmetic surgeries due to its long tendon. It is the most readily available source for tendon grafting. The objective of this study was to determine the prevalence of absence of Palmaris Longus and its association with gender, hand dominance and absence of FDS (flexor digitorum superficialis) tendon to little finger among Malay population.

METHODS

An analytical cross sectional study design was used and a self-administered proforma was distributed for data collection. 1239 Malay secondary school children in Putrajaya were tested for absence of Palmaris Longus using Schaffer's test. 4 additional tests namely Thompson's test, Mishra's test I, Mishra's test II and Pushpakumar's 'two-finger sign' method were used to confirm its absence in respondents with negative Schaffer's test. Function of Flexor Digitorum Superficialis tendon to little finger was determined by flexing PIP of little finger while hyperextend the other fingers.

RESULTS

The prevalence of absence of Palmaris Longus was 11.7%. Left side absence of Palmaris Longus was much common. There was a significant association between absence of Palmaris Longus with gender in which female had higher prevalence of absence of Palmaris Longus than male.

CONCLUSIONS

In conclusion, the prevalence of absence of Palmaris Longus in Malay population was lower than Indian but higher than Chinese population. Females had higher prevalence of absence of Palmaris Longus and no association can be found with hand dominance and absence of Flexor Digitorum Superficialis tendon to little finger.

Congenital absence of the palmaris longus muscle: A meta-analysis comparing cadaveric and functional studies

The aim of our paper was to provide comprehensive data on the prevalence of absence of palmaris longus muscle (PLM) and its anatomical characteristics and conduct two separate meta-analyses comparing cadaveric and functional studies while identifying variation among different ethnic groups. An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included prevalence of absence of PLM among subjects, ethnicity, laterality, side, and gender. Our main findings revealed that the absence of PLM is more frequently reported in functional studies. Moreover, functional tests likely overestimated the absence of PLM and recommend future studies to assess the validity of functional tests and use an imaging assessment prior to excluding the use of a palmaris longus tendon graft in patients in whom a function test identified the absence of PLM.

That Tendon is the Median Nerve: Perils of a Palmaris Longus Deficient Wrist

BACKGROUND

To document the course of the median nerve in the distal forearm in palmaris longus (PL) deficient forearms and elucidate features that help distinguish it from the PL.

METHODS

In the cadaveric study, 56 cadaveric forearms were dissected and the location and course of the median nerve were documented. In the clinical study, 20 healthy subjects with absent PL were examined with provocative tests to elucidate the PL (Schaeffer's test and Thompson's test), and modified Durkan's and Phalen's tests. In the imaging study, one subject with a clearly visible and palpable median nerve was further evaluated with MRI with a superficial fiducial marker.

RESULTS

Cadaveric dissection revealed that the median nerve was deep to the antebrachial fascia and superficial to the FDS tendons in the distal forearm. In 9 specimens without a PL, the median nerve was the most superficial structure deep and lay draped over the FDS tendons. In the clinical study, PL absence was bilateral in 4 subjects and unilateral in 16. The nerve was visible and palpable in 4 forearms and palpable but not visible in 20 forearms. In all 24 forearms, the nerve was palpable as a lax, mobile, cord-like structure that could be rolled over the taut FDS tendons. Tinel's and Durkan's signs were positive in 11 subjects. In the imaging study, MRI confirmed that the palpable structure was the median nerve.

CONCLUSIONS

Unlike the PL, the nerve is non-contractile and remains flaccid on provocative testing. It is usually palpable and may also be visible in thin forearms. Careful scrutiny may reveal it to be distinct from, and draped over underlying FDS tendons. These findings may help avoid inadvertent median nerve harvest in place of a PL tendon graft.

The Prevalence of Absence of the Palmaris Longus Muscle Tendon in the North of Iran: A Comparative Study

BACKGROUND

The palmaris longus is a degenerating weak flexor muscle in the anterior of the forearm. Many techniques for clinically determining the presence of the palmaris longus have been described. Ethnic variations in the prevalence of the absence of the palmaris longus are well known.

OBJECTIVES

This study considered the prevalence of absence of the palmaris longus muscle tendon in the north of Iran.

PATIENTS AND METHODS

The presence of the palmaris longus was clinically determined in 562 men and women from the Guilan population, using the standard technique (Schaeffer's test). In subjects with an absent palmaris longus, three other tests (Thompson, Pushpakumar and Mishra tests) were performed to confirm the absence.

RESULTS

The overall prevalence of right, left, bilateral and total absence of the palmaris longus were 4.1%, 5.2%, 3.9% and 13.2%, respectively. There was no significant difference in its absence with regard to the body side or gender (P > 0.05).

CONCLUSIONS

This study demonstrated that the presence of the palmaris longus muscle tendon in the Guilan population was considerably higher than the absence of the palmaris longus tendon. The overall prevalence of right, left, bilateral and total absence of the palmaris longus was not significantly different between men and women. The prevalence of the left-absent palmaris longus was more common in the present study.

Palmaris Longus Muscle's Prevalence in Different Nations and Interesting Anatomical Variations: Review of the Literature

The prevalence of the palmaris longus (PL) muscle varies more than any other muscle in the human body. Its absence across the world ranges between 1.5% and 63.9%. It presents with many different anomalies, discovered either clinically, intraoperatively or after anatomical examination of cadavers. This paper includes recent studies and reports about the presence and variations of the PL muscle, thereby illustrating the differences between ethnic groups, as well as emphasizing the different ways of finding it, during daily clinical and surgical practice.

Palmaris longus absence in six largest Indonesian ethnicities and its relationship with gender, ethnicity, and hand dominance

Background: Palmaris longus (PL) tendon is often used as graft in tendon or ligament reconstruction. PL absence is a normal variation in human body. Its prevalence was different in various population. Serbian population had an absence rate of 42.4%, but in the Korean population it was only 4.0%. This study aimed to determine the prevalence of PL absence in various ethnic of Indonesian population and its relationship with gender and side of hand dominance. Methods: We conducted a cross-sectional study in 1230 people from six ethnicities in Indonesia. The absence of PL was determined by Schaeffer test and confirmed with Mishra and Thompson test. Data collection was performed by a single examiner in various cities in Indonesia. The relationship between PL absence with ethnicity, gender, and hand dominance were determined by Chi-square test. Results: Prevalence of PL absence in overall Indonesian population was 10.4% (bilateral 37.5% and unilateral 62.5%). The highest were in Batak and Madura ethnicities (15.5%), followed by Sunda (11.8%), Java (10.0%), Betawi (6.0%), and the lowest was Minang ethnicity (4.1%) (p = 0.008). Prevalence of PL absence in female and male were 10.7% 10.2%, respectively, p > 0.05).Conclusion: Compared to range of prevalence in other countries in the world, prevalence of PL absence in Indonesian population was moderate (10.4%). There was significant difference found between ethnicity, but not in gender. Surgeon should consider this data when planning for reconstruction procedures using PL graft in Indonesian population.

Use of the tendon of the palmaris longus muscle in surgical procedures: study on cadavers

Objective

Demonstrate that the tendon of palmar long can be estimated in relation to its length and width before using it as a graft in surgical procedure.

Methods

There were examined 60 forearms of 30 corpses of black ethnicity; measure the length and width of the tendon of the palmaris longus muscle and compared the length of the forearm.

Results

There are notes their absence unilateral right in two female corpses. The medium length and width were more or less respectively 11.9, 15.2 mm and 4.1 + 1.5 mm. The total average forearm length of 275.4 was more or less 17.9 mm.

Conclusion

There is a significant relationship between the length of the tendon and the length of the forearm; so we can evaluate the size of the tendon of the palmaris longus muscle when it is necessary to use it for grafts. Levels of Evidence IV, Case series.

Clinical prevalence of palmaris longus agenesis: a systematic review and meta-analysis

We report a systematic review and a proportion meta-analysis of prevalence studies evaluating the prevalence of palmaris longus agenesis (PLA) in the literature. The overall PLA rate was defined to be the primary outcome. Secondary outcomes were rates of PLA in relation to ethnicity, laterality, side, gender, age, and hand dominance. We identified 26 articles which met the inclusion criteria. Meta-analyses showed an overall PLA pooled rate of 20.25%, higher than the commonly reported overall rate of 15%. Our results also showed significantly lower pooled rates in Africans (11.3%) and East Asians (4.5%) when compared to Arab Middle Eastern population (41.7%). A subgroup analysis of the African group showed a pooled rate of 2.71%, the lowest, in the East and South East African population. The pooled rate was 26.3% among Caucasians, 26.16% among South and Southeast Asians and 34.13% among Turkish. In discordance with the literature, PLA was statistically more predominant on the right side. No significant differences in PLA rates were found for laterality, gender, the combination of gender and side or the combination of gender and laterality. The lowest rate of PLA found in East and South East African populations might be indicative of the subsequent phylogenetic degeneration of the palmaris longus muscle in modern humans after the "Out of Africa" migration.