Risk Factors for Requiring Ulnar Superficialis Slip Resection During Trigger Finger Release.

PURPOSE: Ulnar superficialis slip resection (USSR) has been described to address persistent postoperative triggering following trigger finger release (TFR). The primary purpose of our study was to evaluate the results of simultaneous TFR and USSR under wide-awake local anesthesia no tourniquet (WALANT). The secondary purpose was to identify patient characteristics and risk factors associated with persistent triggering following A1 pulley release requiring USSR. METHOD: We retrospectively identified 1,005 patients who underwent TFR at one institution by a single fellowship-trained, hand surgeon under WALANT from 2015 to 2023. Nine hundred ninety-two patients were treated with TFR alone. Twelve patients (1.2%) underwent USSR because of persistent triggering that was identified in the operating room after release of the A1 pulley. An age-, sex-, and body mass index-matched cohort of 28 patients who underwent TFR alone was created. Medical records were reviewed for demographics and complications. RESULTS: A total of 12 patients (14 digits) underwent TFR with USSR. The long finger was the most commonly affected finger (6, 42%). Patients in the USSR group had more average lifetime trigger fingers compared with the control group (4 vs 1). Additionally, the percentage of patients who had previously undergone TFRs for other fingers was higher in the USSR group (100%) compared with the control group (36%). After surgery, 6 patients (4 USSR and 2 control) underwent formal hand therapy for postoperative stiffness with USSR patients receiving therapy more often than controls. CONCLUSIONS: Although uncommon, some patients (1.2%) who undergo TFR require USSR for persistent triggering following A1 pulley release. Patients who have had more lifetime trigger fingers and/or who have previously undergone TFR for other fingers are more likely to need USSR. No serious complications were incurred by patients who underwent USSR, but these patients may benefit from hand therapy compared to those undergoing isolated TFR. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Prevalence of the Absence of the Palmaris Longus and Functional Flexor Digitorum Superficialis of the Little Finger in the Indian Population.

Background The absence of the palmaris longus (PL) varies with race. The presence of a functional flexor digitorum superficialis (FDS) of the little finger also varies widely. The aim of this study is to determine the prevalence of the absence of the PL and functional FDS of the little finger in the Indian population. Materials and Methods This is a prospective observational study conducted as a part of the Indian normative data project of the Indian Society for Surgery of the Hand. The presence of the PL was assessed by Schaeffer's test. The function of the FDS was assessed by the standard test and modified test and its function designated as absent, present independently, or present combinedly with the ring finger FDS. Results A total of 200 volunteers including 84 males and 116 females in the 21- to 60-year age group were examined. Of the 400 hands examined, the PL was absent in 26 upper limbs (6.5%). The PL was absent unilaterally in 12 individuals (6%) and bilaterally in 7 individuals (3.5%). Of the 400 little fingers examined, FDS function was absent in 72 fingers (18%), while 67 fingers (16.75%) had a common function and 261 fingers (65.25%) had an independent function. Only 2% had a bilateral absence of both the PL and functional FDS tendons and 5% had a unilateral absence of both tendons. Conclusion The PL and FDS of the little finger were more absent in the right side than in the left side, but the difference was not statistically significant. There was no significant association between the absence of the PL and the absence of the functional FDS of the little finger.

Endoscopic carpal tunnel release with opponensplasty using ring finger flexor digitorum superficialis under WALANT with ultrasound assistance.

In patients with severe, long-standing carpal tunnel syndrome and thenar muscle atrophy, nerve decompression alone is unlikely to restore thumb opposition. A multitude of tendon transfer techniques have been described to restore thumb opposition. We describe the technique of an endoscopic carpal tunnel release with opponensplasty using ring finger flexor digitorum superficialis (FDS) tendon under Wide Awake Local Anaesthesia No Tourniquet (WALANT) and ultrasound assistance.

Central slip defect reconstruction utilizing partial ulnar side of flexor digitorum superficial tendon for chronic boutonniere deformity: A case report.

Background: Post-traumatic central slip injuries, resulting in boutonniere deformity, are a complex issue that can significantly impact hand function and quality of life. The deformity should be easily reducible in the acute phase, but if left untreated, it shortens the oblique retinacular ligament, leading to chronic contracture. This is a challenging issue in hand surgery, as chronic central slip defects cannot be sutured like other tendon. Various methods for reconstructing central slips have been discussed, but the best method for subacute or chronic injuries remains unclear. This case presents a case of chronic traumatic boutonniere deformity with central slip defect reconstruction. Case report: A 65-year-old male patient presented with swelling and boutonniere deformity on the digiti III of the right hand. The patient had previously fallen from a motorcycle, and the patient's right middle finger got was by a motorcycle six months ago. After the incident, the patient's right middle finger cannot be fully extended. The patient's right hand showed edema with flexion of the interphalangeal (PIP) joint and hyperextension of the distal interphalangeal (DIP) joint. The Range of Motion (ROM) of the PIP joint right middle finger was 45-110 degrees. The X-ray of the right hand AP/oblique showed no bone involvement in the deformity. The patient underwent central slip defect reconstruction utilizing the partial ulnar side of the flexor digitorum superficial tendon. A PIP joint extension splint was applied for 2 weeks. Active and passive exercise of the ROM of the PIP joint began after 2 weeks of PIP extension joint splinting. The patient's ROM of the PIP joint (0-90 degrees) significantly improved 1 month after surgery. The patient's ROM of the PIP joint returned to normal after 2 months after surgery. The function of the patient's right hand is evaluated with the DASH score, which improves significantly from 50 to 4.2. Conclusion: Central slip defect reconstruction utilizing the partial ulnar side of the flexor digitorum superficial tendon is a reliable method for traumatic chronic boutonniere deformity and results in great functional outcomes after 2 months of follow-up. Central slip defect reconstruction utilizing the partial ulnar side of the flexor digitorum superficial tendon is a simple and cost-effective method compared to other methods.

Relationship between the elasticity of the forearm flexor-pronator muscles and elbow valgus torque in young baseball pitchers: a descriptive laboratory study.

BACKGROUND: The forearm flexor-pronator muscles act as a dynamic elbow stabilizer against elbow valgus load during baseball pitching. The elasticity of these muscles increases with pitching. However, it is unclear whether increased muscle elasticity is associated with greater elbow valgus torque during pitching. This study aimed to determine the relationship between the elasticity of the forearm flexor-pronator muscles and elbow valgus torque during pitching in young baseball pitchers. METHODS: We recruited 124 young baseball pitchers aged 9 to 12 years. The exclusion criteria included current pain with pitching, history of surgery on the tested extremity, or injuries on the tested extremity within the past 12 months. Before the examination, participants completed a questionnaire about their age, height, weight, dominant arm, and practice time per week. The strain ratios of flexor carpi ulnaris (FCU), flexor digitorum superficialis (FDS), and pronator teres as the index of muscle elasticity were measured using ultrasound strain elastography. Participants pitched 3 fastballs at a distance of 16 m (52 ft 6 in) with maximum effort while wearing a sensor sleeve that recorded the elbow valgus torque. A multiple linear regression analysis was conducted to examine the association between muscle elasticity and elbow valgus torque, adjusting for age, height, weight, and practice time. RESULTS: The final analysis included 107 pitchers. After adjusting for covariates, increased strain ratio of the FCU was significantly associated with greater elbow valgus torque (coefficients = 0.038, 95% confidence interval, 0.016-0.059, P < .001). Similarly, increased strain ratio of the FDS was significantly associated with greater elbow valgus torque (coefficients = 0.027, 95% confidence interval, 0.013-0.042, P < .001). CONCLUSION: The high elasticities of the FCU and FDS were associated with greater elbow valgus torque during pitching in young baseball pitchers. The high elasticity of these muscles is a protective response and may be necessary for young baseball pitchers with greater elbow valgus torque during pitching. Among young baseball pitchers with greater elbow valgus torque, those who are unable to produce the higher elasticities of these muscles could have greater elbow valgus load during pitching and be at a higher risk for elbow injuries. The measurement of the elasticities of the FCU and FDS may be useful for identifying young baseball pitchers at risk of sustaining elbow injuries.

Muscular branches from the ulnar artery are the basis for a pedicled partial flexor digitorum superficialis muscle flap.

The feasibility of a pedicled flexor digitorum superficialis muscle flap was studied in 10 fresh cadavers. The number, length and distance from the flexion wrist crease of muscular branches from the ulnar artery in the distal 10 cm of the forearm were recorded. The mean number of muscular branches was 2.7 (range 1-4). The mean distance of the most distal branch was 35 mm (range 26-40) from the proximal wrist flexion crease. Its mean length was 20 mm (range 16-26). A partial muscle flap was raised on the most distal branch and transposed over the median nerve in the distal forearm. Dissection and transposition of this flap were feasible in all specimens. The reliable pattern of muscular branches to the flexor digitorum superficialis allows the elevation of a pedicled partial muscle flap that can cover the median nerve in the distal forearm.Level of evidence: V.

Unusual Duplication of Flexor Tendons in the Middle Finger Leading to Trigger Finger: A Case Report and Comprehensive Review.

Duplication of the flexor digitorum profundus (FDP) tendon is an extremely uncommon anatomical anomaly found within the flexor digitorum superficialis (FDS) muscle, with minimal documentation in the current literature. We present the case of a 45-year-old female manual laborer who exhibited symptoms suggestive of trigger finger in her right middle finger. Surgical exploration uncovered a duplicated FDP tendon, a previously unreported anatomical anomaly in this context. Despite attempting conservative treatment initially, surgical intervention involving release of the A1 pulley, excision of the A1 pulley, and identification of the duplicated tendon was performed. The unusual nature of this anatomical variation highlights the need for additional research into its clinical significance and treatment options. This case highlights the significance of conducting comprehensive anatomical assessments to diagnose and treat uncommon variations within the FDS muscle. It underscores the continued need for collaborative research to enhance treatment approaches, especially in instances where trigger finger symptoms are present.

A Comparison of Patient Characteristics and Outcomes Between Patients Receiving Flexor Digitorum Superficialis Slip Excision or Isolated A1 Pulley Release for Trigger Finger.

PURPOSE: Resection of the radial or ulnar slip of the flexor digitorum superficialis (FDS) tendon is a known treatment option for persistent trigger finger. Risk factors for undergoing FDS slip excision are unclear. We hypothesized that patients who underwent A1 pulley release with FDS slip excision secondary to persistent triggering would have a higher comorbidity burden compared to those receiving A1 pulley release alone. METHODS: We identified all adult patients who underwent A1 pulley release with FDS slip excision because of persistent triggering either intraoperatively or postoperatively from 2018 to 2023. We selected a 3:1 age- and sex-matched control group who underwent isolated A1 pulley release. Charts were retrospectively reviewed for demographics, selected comorbidities, trigger finger history, and postoperative course. We performed multivariable logistic regression to assess the probability of FDS slip excision after adjusting for several variables that were significant in bivariate comparisons. RESULTS: We identified 48 patients who underwent A1 pulley release with FDS slip excision and 144 controls. Our multivariable model showed that patients with additional trigger fingers and a preoperative proximal interphalangeal (PIP) joint contracture were significantly more likely to undergo FDS slip excision. CONCLUSIONS: Patients who underwent A1 pulley release with FDS slip excision were significantly more likely to have multiple trigger fingers or a preoperative PIP joint contracture. Clinicians should counsel patients with these risk factors regarding the potential for FDS slip excision in addition to A1 pulley release to alleviate triggering of the affected digit. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Uncommon Presentation of a Giant Cell Tumor of the Tendon Sheath of the Hand: A Case Report.

A giant cell tumor of the tendon sheath (GCTTS) presents as a rare neoplasm demanding a heightened index of suspicion for precise diagnostic evaluation, especially when manifesting in the digital phalanges, as it is part of a group of neoplasms known as tenosynovial giant cell tumors (TCGTs). An accurate and timely diagnosis is crucial, as it significantly enhances treatment outcomes for this heterogeneous group of lesions. We describe the case of a male patient who presented with multiple nodules in the fourth finger of his left hand and was ultimately diagnosed with a localized form of a GCTTS, an unusual presentation for localized forms of this entity. Our objective is to outline the diagnostic and therapeutic approach, discussing options for differential diagnosis and treatment modalities. To achieve this, we conducted a literature review and compared our findings and the observed evolution in our patient. Early recognition of hand tumors allows for timely diagnosis, facilitating optimal resections during surgical procedures. This, in turn, reduces morbidity and enhances the functionality of the affected extremity, as detailed in the current case.

Agenesis of flexor pollicis longus without thenar hypoplasia: a case report and literature review.

We present a case of congenital of flexor pollicis longus agenesis without thenar hypoplasia in a 12-year-old girl with no history of trauma. Two-staged corrective surgery was planned. In the first stage, the flexor pulley was reconstructed using silicone followed by the second stage 3 months later when flexor pollicis longus reconstruction was performed using tendon transfer of the flexor digitorum superficialis. The patient completed post-operative physiotherapy and the result of the surgical treatment in both functional and cosmetic aspects was, in the authors' opinion, excellent.

Anatomical location of motor branch points in the flexor digitorum superficialis for the injection site of botulinum toxin.

OBJECTIVE: To locate the intramuscular nerve branches of the flexor digitorum superficialis (FDS) and determine the accurate site for botulinum toxin injection. DESIGN: This study anatomically dissected 24 arms of 12 fresh adult cadavers to find intramuscular nerve endings in the FDS. The motor branch points (MBPs), proximal limit points (PLPs), and distal limit points (DLPs) of the terminal intramuscular nerve endings were identified. These three parameters were expressed in longitudinal and transverse coordinates in relation to the FDS driving as a reference line. RESULTS: The mean length of the reference line was 234.6 ± 11.2 mm. In the longitudinal coordinate, the MBPs, PLPs, and DLPs were located at 41.6% (standard deviation (SD) 2.6%), 35.1% (SD 4.1%), and 53.4% (SD 4.6%) of the reference line in the first main branch and 72.4% (SD 4.5%), 67.5% (SD 1.5%), and 82.0% (SD 5.7%) in the second main branch, respectively. The mean value of the transverse coordinate was not greatly deviated from the reference line. CONCLUSION: The MBPs of the first and second main branches are located approximately 41.6% and 72.4% of the reference line, which considers the FDS direction, respectively. This finding helps determine the optimal injection site for botulinum toxin in the FDS.

Satisfactory thumb metacarpophalangeal joint stability after ligament reconstruction with flexor digitorum superficialis in children with radial longitudinal deficiency.

We investigated thumb joint stability and patient-reported and functional outcomes a minimum of 1 year after flexor digitorum superficialis opponensplasty and ligament reconstruction in 23 thumbs of 20 consecutive children with radial longitudinal deficiency. In total, 15 thumbs had preoperative multidirectional instability in the metacarpophalangeal joint. We reconstructed 22 ulnar and 16 radial collateral ligaments. At follow-up, all the metacarpophalangeal joints were stable ulnarly. Seven metacarpophalangeal joints were unstable radially despite ligament reconstruction but had no related complaints. We recommend the flexor digitorum superficialis opponensplasty as a safe and reliable procedure in hypoplastic thumbs to create stability and augment thumb strength.Level of evidence: IV.

Anomalous Flexor Digitorum Superficialis Muscle Belly Associated with Carpal Tunnel Syndrome.

Anomalous muscle bellies in the forearm generally are asymptomatic and appreciated in an academic sense during cadaveric dissections. Few prior anatomic variations in muscle bellies have been described with symptoms, and are associated even more rarely with carpal tunnel syndrome (CTS). We discuss the evaluation and management of a case of CTS associated with a muscle belly of the flexor digitorum superficialis to the index within the carpal tunnel.

MRI-Based Evaluation of the Flexor Digitorum Superficialis Anatomy: Investigating the Prevalence and Morphometry of the "Chiasma Antebrachii".

Recent dissection studies resulted in the introduction of the term "chiasma antebrachii", which represents an intersection of the flexor digitorum superficialis (FDS) tendons for digits 2 and 3 in the distal third of the forearm. This retrospective investigation aimed to provide an MRI-based morphologic analysis of the chiasma antebrachii. In 89 patients (41 women, 39.3 ± 21.3 years), MRI examinations of the forearm (2010-2021) were reviewed by two radiologists, who evaluated all studies for the presence and length of the chiasma as well as its distance from the distal radioulnar and elbow joint. The chiasma antebrachii was identified in the distal third of the forearm in 88 patients (98.9%), while one intersection was located more proximally in the middle part. The chiasma had a median length of 28 mm (interquartile range: 24-35 mm). Its distances to the distal radioulnar and elbow joint were 16 mm (8-25 mm) and 215 mm (187-227 mm), respectively. T1-weighted post-contrast sequences were found to be superior to T2- or proton-density-weighted sequences in 71 cases (79.8%). To conclude, the chiasma antebrachii is part of the standard FDS anatomy. Knowledge of its morphology is important, e.g., in targeted injections of therapeutics or reconstructive surgery.

Coexistence of rare varieties of palmaris profundus and flexor superficialis muscle.

The superficial layer of the anterior compartment of the forearm is characterized by different morphological variations. During standard anatomical dissection, two morphological variations in the superficial compartment of the forearm were observed. The first one was the palmaris profundus, which originated from the radius and distally fused with the tendon to 3rd digit (from the flexor digitorum superficialis muscle) inserted on the medial phalanx of the third digit. The second variation was a distinct superficial flexor of the 4th digit represented by one muscle belly with originated from a common mass from the medial humeral epicondyle, passes through the carpal tunnel, and is inserted into the medial phalanx of the fourth digit. The flexor digitorum superficialis muscle was located deeply to it and it was divided only into three tendons (to 2nd, 3rd, and 5th digits). Tendons connected to the 2nd and 3rd digits were crossed with each other at the level of carpal tunnel. From the humeroulnar head of the flexor digitorum superficialis muscle, an additional muscle belly was arising and its tendon was fused with the superficial flexor of the fourth digit. Knowledge about morphological variations in this region is clinically important because of the direct correlation with the median nerve, and the possibility to cause carpal tunnel syndrome.

Dissection, digitization, and three-dimensional modelling: a high-fidelity anatomical visualization and imaging technology.

Technological advances have enabled the development of a novel technique of dissection, digitization and three-dimensional modelling of skeletal muscle and other tissues including neurovascular structures as in situ over the last 25 years. Meticulous serial dissection followed by digitization is used to collect Cartesian coordinate data of the contractile and connective tissue elements throughout the entire muscle volume. The Cartesian coordinate can then be used to construct high-fidelity three-dimensional models that capture the spatial arrangement of the contractile and connective tissue elements as in situ enabling detailed studies of the arrangement of the fiber bundles and their attachment sites to aponeuroses, tendon, and bone. In the laboratory, we have concurrently developed a computational methodology to quantify architectural parameters, including fiber bundle length, pennation angle, volume, physiological cross-sectional area in three-dimensional space. In this paper, a flexor digitorum superficialis specimen will be used to demonstrate the high-fidelity outcomes of dissection, digitization, and three-dimensional modelling. This three-step methodology provides a unique opportunity to study muscle architecture in three dimensions, as in situ. Knowledge translation from the anatomy laboratory to the clinical setting has been highly successful.

Possible Points of Ulnar Nerve Entrapment in the Arm and Forearm: An Ultrasound, Anatomical, and Histological Study.

BACKGROUND: Ulnar nerve entrapment is one of the most common entrapment neuropathies, usually occurring in the cubital tunnel of the elbow and in Guyon's canal of the wrist. However, it can also occur at other anatomical locations. PURPOSE: Our aim was to review other possible locations of ulnar nerve entrapment in an ultrasound and anatomical study. MATERIAL AND METHODS: Eleven upper limbs from eight adult corpses were ultrasonographically examined and subsequently dissected in a dissection laboratory. Four specific anatomical points were analysed, and any anatomical variations were documented. Moreover, six samples of the nerve were taken for histological analysis. RESULTS: Distinct anatomical relationships were observed during ultrasound and dissection between the ulnar nerve and the medial intermuscular septum, the triceps aponeurosis, Osborne's fascia at the elbow, the arcuate ligament of Osborne and the intermuscular aponeurosis between the flexor carpi ulnaris and the flexor digitorum superficialis muscles. A statistical study showed that these locations are potential areas for ulnar nerve compression. In addition, a fourth head of the triceps brachii muscle was found in some specimens. CONCLUSION: Results demonstrate that ultrasound is a good tool to investigate ulnar nerve entrapment neuropathy and to identify other anatomical points where the nerve can remain compressed.

A Rare Case of an Isolated Neglected Subcutaneous Rupture of the Flexor Digitorum Superficialis in a Climber: Successful Surgical Treatment and Review of the Literature.

Isolated neglected subcutaneous rupture of the flexor digitorum superficialis (FDS) in zone III of the hand is a rare injury that is distinct from subcutaneous rupture of the deep flexor tendons in the fingers. While a few cases have been reported in the literature, the pathophysiology of this injury remains poorly understood. In this article, we present a case study of a climber who experienced an isolated subcutaneous rupture of the FDS following a sports accident. The patient's diagnosis was initially delayed due to an unclear clinical presentation. However, surgical intervention was successfully performed, resulting in positive clinical outcomes at the one-month follow-up. This case highlights the importance of considering isolated subcutaneous rupture of the FDS as a potential injury in climbers and other individuals who engage in high-impact sports.

Unilateral Right-Sided Progressive Flexor Digitorum Superficialis Brevis to the Little Finger: A Case Report With Review of Literature.

The flexor digitorum superficialis (FDS), an intermediate flexor of the forearm, can present with variations in the musculature or tendons. Here, we report a very rare anomaly of the FDS-V tendon replaced by a muscle belly in the palm, which was a progressive variation. This variation was found in a 60-year-old female cadaver on the right hand. The anomalous belly took its origin from the center of the volar aspect of the flexor retinaculum and was inserted into the A2 pulley of the middle interphalangeal joint to the little finger. The anomalous muscle was innervated by a branch of the median nerve. Knowledge of such variations will be useful for hand surgeons for meticulous planning of surgeries of the palm. The occurrences of such variations might interfere with the biomechanics of the FDS tendons.