Secondary Linburg-Comstock syndrome post-trapeziectomy surgery

Linburg-Comstock syndrome is an acquired symptomatic restrictive thumb index finger flexor tenosynovitis involving a hypertrophic tenosynovium between flexor pollicis longus and flexor digitorum profundus. Patients may report synkinetic movement of the thumb and index finger, pain and swelling. We present the case of a woman in her 80s who presented with painless Linburg-Comstock syndrome after a trapeziectomy 4 months earlier for trapeziometacarpal arthritis. A literature review of PubMed-indexed case reports found that Linburg-Comstock syndrome has never been described in a post-trapeziectomy patient. This unusual presentation that arose as a side effect of hand surgery remains unreported in the literature. We present this unique complication as the first such case in the world. This case report is a valuable addition to the existing knowledge on the complications of trapeziectomy surgery.

An investigation into the reliability and methodology of the Linburg-Comstock anomaly clinical test

STUDY DESIGN

This is a cross-sectional study.

INTRODUCTION

An intertendinous connection between the flexor pollicis longus (FPL) and index flexor digitorum profundus (IFDP) tendons causes involuntary index flexion during active thumb flexion and has been named the Linburg-Comstock anomaly (LCA). It may become symptomatic or cause functional limitations. Literature has documented the prevalence to range from 13% to 70%. Cadaver studies have reported an anatomical connection in 5% to 25%.

PURPOSE

This study aimed to examine the methodology and reliability of the LCA clinical diagnostic test and to explore the wide range of reported incidence and the discrepancy between cadaver and subject prevalence.

METHODS

Two examiners observed for the presence of involuntary index flexion during 3 separate variations of thumb flexion in 67 subjects (134 limbs); results were considered positive if involuntary flexion occurred at either index interphalangeal joint. Intertester reliability was assessed using Cohen's kappa coefficient. The volar forearm and wrist of 53 cadavers (106 limbs) were dissected and assessed for an observable and mechanical tendinous connection between the FPL and IFDP tendons.

RESULTS

Prevalence for subjects (5%-32%) was at the lower end of the range of previously reported values; results differed with altering thumb flexion motion. Observation for the presence of an intertendinous connection between the FPL and IFDP tendons in cadaver specimens (23%) fell within previously reported ranges. Intertester reliability coefficients ranged from no to weak agreement and varied according to specific thumb flexion motion performed during the test.

CONCLUSIONS

The identification of index finger flexion during thumb flexion varied both with thumb flexion motions and with whether flexion was assessed at the index proximal interphalangeal or distal interphalangeal joint. Intertester reliability was low for all variations of the LCA clinical test performed. The wide range in previously reported LCA incidence may be due to variability in testing procedure, and there is a need to establish a reliable and valid clinical test for this potentially symptomatic anatomic anomaly.

Outcome of carpal tunnel release surgery in patients with and without Linburg-Comstock anomaly

Anatomical variations may entail increased volume within the carpal tunnel and consequently the development of carpal tunnel syndrome (CTS) symptoms. The clinical importance of anomalous connection between the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) tendons was described by Linburg and Comstock. The objective of the present study was to compare postoperative outcomes of carpal tunnel release surgery in patients with and without Linburg-Comstock anomaly (LCA). Hands of CTS patients with and without LCA were evaluated for finger sensitivity, grip, tip, key and tripod pinch strength, pain intensity and Boston Carpal Tunnel Questionnaire score. Patients were evaluated preoperatively and 1, 3 and 6 months after surgery. Forty-six hands in 36 CTS patients with LCA and 50 hands in 38 patients without LCA were included. On all study parameters, no significant difference was found between CTS patients with versus without LCA. As outcomes are similar in both cases, LCA resection is not useful in patients with LCA and CTS. Preoperative diagnosis is unnecessary and screening for LCA is non-contributive for CTS evaluation.

Prevalence of the Linburg-Comstock Anomaly in a Brazilian Population Sample

Objective  To determine the prevalence of the Linburg-Comstock anomaly in a Brazilian population sample. Methods  A cross-sectional observational study was carried out between October 2017 and April 2018. We included male and female volunteers aged 18 years or older. The presence of the Linburg-Comstock anomaly was determined by performing the clinical tests described by Linburg and Comstock. The data were analyzed using the GraphPad Prism software, and we considered differences with p  < 0.05. Results  The study analyzed 1,008 volunteers (2,016 hands) with a mean age of 38.3 years, 531 (52.67%) of which were male, and 477 (47.33%) were female. The Linburg-Comstock anomaly was diagnosed in 564 (55.95%) individuals, and it was bilateral in 300 (53.2%) of them, right-sided in 162 (28.72%), and left-sided in 102 (18.08%). No significant differences were found when comparing the prevalence between genders. However, a the prevalence of the right-sided anomaly in the male population (n = 99; 70.21%) was higher than in the female one (n = 63; 51.21%), with p  = 0.0016. In addition, the presence of pain by the maneuver described by Linburg and Comstock was more prevalent in women (n = 150; 54.94%) than in men (n = 105; 36.08%), with p  = 0.0001. These results show the importance of epidemiological studies on the Linburg-Comstock anomaly, mainly in order to investigate the presence of associated conditions. Conclusion  The prevalence of the Linburg-Comstock anomaly in the studied population was of 55.95%, and it was bilateral in 53.2% of the volunteers. The presence of the connection was observed more frequently in the right side and among men, but the pain symptom was more frequent among women.

Linburg-Comstock: Is Overuse an Etiological Factor?

Background

Linburg-Comstock anomaly is typically defined as a tenosynovial interconnection between flexor pollicis longus and flexor digitorum profundus tendon of the second finger. There are several studies stating that the current anomaly is congenital or acquired. The aim of this study is to reveal whether overuse, which is mostly reported as an acquired etiologic factor, effective in development of the current anomaly.

Methods

Three hundred thirteen medical secretaries who work with computer keyboard at least 6 hours a day were defined as study group. Three hundred twenty-three volunteers without jobs who necessitate continuous and repetitive hand and finger activities were defined as control group. All individuals were examined by an orthopaedic surgeon. Additionally, cases with Linburg-Comstock anomaly were evaluated in respect of forearm pain and subjective findings of carpal tunnel syndrome.

Results

Linburg-Comstock anomaly was determined in 27.8% cases of medical secretary group and in 32.2% of healthy control group. In medical secretaries with Linburg-Comstock anomaly, 25.3% had forearm pain and 5.7% had findings of carpal tunnel syndrome. In control group with Linburg-Comstock anomaly, 21.2% had forearm pain and 13.5% had findings of carpal tunnel syndrome. No relationship was found between overuse of the hand and Linburg-Comstock anomaly and the symptoms accompanying the anomaly.

Conclusions

The current study reveals that overuse is not an etiologic factor in Linburg-Comstock anomaly existence and related symptoms. We think that the current anomaly develops on congenital basis rather than acquired factors.