Relationships between the global symptom score and electrophysiological findings after surgical release for carpal tunnel syndrome: Indications and outcomes.

PURPOSE: Regarding surgical indications for carpal tunnel syndrome (CTS), the hypothesis that the recovery processes of subjective symptoms differ among pain, sensory, and motor symptoms and correlate with recovery in objective nerve conduction studies was examined in the present study. METHODS: The global symptom score (GSS) is a method used to assess clinical outcomes and covers subjective symptoms, including pain (pain and nocturnal awakening), sensory (numbness and paresthesia), and motor (weakness/clumsiness) symptoms. The relationships between long-term changes in GSS and recovery in nerve conduction studies were investigated. RESULTS: Forty patients (40 hands) were included (mean age 65 years; 80% female; 68% with moderate CTS: sensory nerve conduction velocity < 45 m/s and motor nerve distal latency > 4.5 ms). Pain and nocturnal awakening rapidly subsided within 1 month after surgery and did not recur in the long term (median 5.6 years). Paresthesia significantly decreased 3 months after surgery and in the long term thereafter. Weakness/clumsiness significantly decreased at 1 year. Sensory nerve distal latency, conduction velocity, and amplitude significantly improved 3 months and 1 year after surgery, and correlated with nocturnal awakening in the short term (3 months) in moderate CTS cases. The patient satisfaction rate was 91%. CONCLUSION: Rapid recovery was observed in pain and nocturnal awakening, of which nocturnal awakening correlated with the recovery of sensory nerve conduction velocity. Patients with pain symptoms due to moderate CTS may benefit from surgical release.

Scoping review of the palmaris profundus muscle: anatomy of a rare variant and its role in carpal tunnel syndrome.

The palmaris profundus muscle is a rare anatomical variation of the forearm muscles. It has been described in both cadaveric and clinical studies as a possible cause of carpal tunnel syndrome. We observed three cases of this variant in recent years and decided to perform a scoping review of this uncommon anatomical entity. Major databases were searched to identify all relevant clinical and anatomical studies containing anatomical descriptions of the muscle, including its origin, insertion, and concomitant presence of the proper palmaris longus muscle or the bifid median nerve. In clinical cases, we studied the surgical approach. Sixty-four articles met our inclusion criteria and contained 88 cases of palmaris profundus muscle. The most common origin was the ventral aspect of the radius in the area of insertion of the pronator teres muscle observed in 11 cases (12.5 %). We found 65 cases (73.3%) in which the tendon was inserted into the palmar aponeurosis or palmar fascia after entering the carpal canal. The concomitant presence of the proper palmaris longus muscle was described in 47 cases (53.4%). We identified 10 cases (10.8%) of the bifid median nerve. In 49 of 69 clinical cases (71%), the surgical approach was to resect the variant muscle. The importance of this variant should not be underestimated due to its potential to compress the median nerve. We found a significant disparity in the muscle origin sites, but uniformity of muscle insertion. In cases where the muscle is found during carpal canal surgery, it should be partially resected to ensure complete nerve decompression.

Non-Surgical Carpal Arch Space Augmentation for Median Nerve Decompression.

The carpal tunnel is a tightly bounded space, making the median nerve prone to compression and eventually leading to carpal tunnel syndrome. Carpal tunnel release surgery transects the transverse carpal ligament to expand the tunnel arch space, decompress the median nerve, and relieve the associated symptoms. However, the surgical procedure unavoidably disrupts essential anatomical, biomechanical and physiological functions of the wrist, potentially causing reduced grip strength, pillar pain, carpal bone instability, scar tissue formation, and perineural fibrosis. It is desirable to decompress the median nerve without surgically transecting the transverse carpal ligament. This paper is to review several approaches we have developed for nonsurgical carpal arch space augmentation (CASA), namely, radio ulnar wrist compression, muscle-ligament interaction, palmar pulling, and collagenolysis of the transverse carpal ligament. Briefly summarized is the research work on the CASA topic about theoretical considerations, in vitro and in situ experiment, computational modeling, and human subject studies with asymptomatic and carpal tunnel syndrome hands.

Restoration of intrinsic hand function by superficial radial nerve: an anatomical study.

BACKGROUND: The contralateral seventh cervical (cC7) nerve root transfer represents a cornerstone technique in treating total brachial plexus avulsion injury. Traditional cC7 procedures employ the entire ulnar nerve as a graft, which inevitably compromises its restorative capacity. OBJECTIVE: Our cadaveric study seeks to assess this innovative approach aimed at preserving the motor branch of the ulnar nerve (MBUN). This new method aims to enable future repair stages, using the superficial radial nerve (SRN) as a bridge connecting cC7 and MBUN. METHODS: We undertook a comprehensive dissection of ten adult cadavers, generously provided by the Department of Anatomy, Histology, and Embryology at Fudan University, China. It allowed us to evaluate the feasibility of our proposed technique. For this study, we harvested only the dorsal and superficial branches of the ulnar nerve, as well as the SRN, to establish connections between the cC7 nerve and recipient nerves (both the median nerve and MBUN). We meticulously dissected the SRN and the motor and sensory branches of the ulnar nerve. Measurements were made from the reverse point of the SRN to the wrist flexion crease and the coaptation point of the SRN and MBUN. Additionally, we traced the MBUN from distal to proximal ends, recording its maximum length. We also measured the diameters of the nerve branches and tallied the number of axons. RESULTS: Our modified approach proved technically viable in all examined limbs. The distances from the reverse point of the SRN to the wrist flexion crease were 8.24 ± 1.80 cm and to the coaptation point were 6.60 ± 1.75 cm. The maximum length of the MBUN was 7.62 ± 1.03 cm. The average axon diameters in the MBUN and the anterior and posterior branches of the SRN were 1.88 ± 0.42 mm、1.56 ± 0.38 mm、2.02 ± 0.41 mm,respectively. The corresponding mean numbers of axons were 1426.60 ± 331.39 and 721.50 ± 138.22, and 741.90 ± 171.34, respectively. CONCLUSION: The SRN demonstrated the potential to be transferred to the MBUN without necessitating a nerve graft. A potential advantage of this modification is preserving the MBUN's recovery potential.

Infrared thermographic changes after decompression surgery in patients with carpal tunnel syndrome.

BACKGROUND: Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes. METHODS: In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively. RESULTS: A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p <  0.001 for all comparisons). CONCLUSIONS: Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.

Intravascular papillary hemangioendothelioma disguised as a peripheral sheath tumor of median nerve at the wrist: a case report and literature review.

BACKGROUND: Intravascular papillary hemangioendothelioma (IVPH) is a benign lesion previously reported in the nasal cavity, neck, upper extremities, and breast. Diagnosis with cross-sectional imaging can prove difficult, with histopathological examination necessary for diagnosis. IVPH resulting in carpal tunnel symptoms is quite rare. CASE PRESENTATION: We report the case of a 37-year-old woman who presented with a radial, volar right wrist mass enlarging over the span of 5 years. She noted numbness and tingling in her wrist and thumb, exacerbated by minor accidental collisions and wrist hyperextension. There was no antecedent trauma. On examination, a mildly tender, mobile mass was evident at the volar aspect of the right wrist. Magnetic resonance imaging (MRI) with contrast demonstrated a lobulated, predominantly T2 hyperintense, heterogeneously enhancing mass thought to be a peripheral nerve sheath tumor. The patient elected for surgical excision of the mass, and the histopathological examination showed organizing thrombi with prominent papillary endothelial hyperplasia. At the 2-month follow-up, the patient had full range of motion of her fingers and wrist, with subjectively normal sensation in the distribution of the median nerve. CONCLUSION: Carpal tunnel syndrome, in exceedingly rare occasions, can result from an IVPH. MRI findings may be confused with more common entities. Histopathological confirmation remains necessary for conclusive diagnosis.

Preliminary Prospective Preoperative and Postoperative Evaluation of Median Nerve Stiffness by Using Sonoelastography.

ABSTRACT: Carpal tunnel syndrome is the most common peripheral nerve entrapment syndrome. No previous studies have compared preoperative and follow-up sonoelastography results or investigated the correlation of median nerve stiffness with the subjective/objective outcomes. Therefore, the aim of this study was to compare the preoperative and postoperative elastography after carpal tunnel release and find the correlation with associated subjective/objective outcomes.From May 2017 to March 2020, 32 patients (6 males, 26 females; 34 hands) with carpal tunnel syndrome were enrolled in this prospective study. Demographic data, QuickDASH score (Chinese version), Boston Carpal Tunnel Questionnaire (Chinese version), nerve conduction velocity/electromyography, and median nerve stiffness by sonoelastography were recorded.Comparisons of preoperative and average sonoelastography findings 1.5 years postoperatively showed a significant decrease in stiffness presented by velocity (Vs) (preoperative Vs, 4.63 ± 1.27 m/s, vs postoperative Vs, 3.39 ± 0.59 m/s; P < 0.001). Changes in subjective functional outcomes also showed the same significant trend. Based on the neurophysiologic study, the improvement of nerve conduction study and elastography have the significant correlation.The same trend of preoperative and postoperative changes in median nerve stiffness and subjective questionnaires/objective neurophysiologic studies may imply that sonoelastography can be used to assess the response to surgery in patients with carpal tunnel syndrome.

Base of the Third Metacarpal as a Palpable and Reliable Landmark for Identifying the Median Nerve's Thenar Branch.

PURPOSE: The objective of this study was to investigate whether the base of the third metacarpal can predict the location of the thenar branch (TB) of the median nerve and the accuracy of palpating the base of the third metacarpal. METHODS: In 15 patients with ulnar nerve lesions around the elbow, we transferred the opponens motor branch to repair the deep terminal division of the ulnar nerve (DTDUN). Before surgery, we located the TB by palpating the base of the third metacarpal volarly. During surgery, we placed three needles at the following places: one at the entrance of the TB into the abductor pollicis brevis, another at the point where the TB contacted the thenar muscles, and third at the DTDUN's trajectory over the third metacarpal. We obtained fluoroscopic images and measured distances between the needles and structures with image software. We also examined the relationship between the TB, DTDUN, and the volar tubercle of the base of the third metacarpal in cadaver hands. Finally, we invited 22 surgeons to palpate the base of the third metacarpal on volunteer hands and verified their accuracy using fluoroscopy. RESULTS: During surgery, after dissection and palpation of the TB, under fluoroscopy, we confirmed that the palpable bone prominence was the base of the third metacarpal. In cadaver dissections, we observed the TB crossing the volar tubercle of the base of the third metacarpal superficially from proximal to distal and from ulnar to radial. The DTDUN was, on average, 14 mm distal to the base of the third metacarpal distal limit. In total, 19 of the 22 surgeons correctly identified the base of the third metacarpal and consequently the trajectory of the TB. CONCLUSIONS: The palpable base of the third metacarpal can be used to determine the trajectory of both the TB and DTDUN. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Cross-Sectional Area of the Median Nerve as a Prognostic Indicator in Carpal Tunnel Syndrome Treated With Local Steroid Injection.

PURPOSE: Local steroid injection is an effective treatment modality for carpal tunnel syndrome. This study aimed to investigate the success rate of ultrasonography-guided local steroid injection and determine the prognostic value of the cross-sectional area (CSA) of the median nerve for steroid injection. METHODS: We retrospectively evaluated 40 patients with carpal tunnel syndrome whose median nerve CSA was >15 mm2 (large-CSA group; n = 16) or ≤15 mm2 (small-CSA group; n = 24). The CSA was measured using ultrasonography, and all the patients were treated with ultrasonography-guided corticosteroid injection. Demographic characteristics, symptoms, initial QuickDASH score, Boston Carpal Tunnel Questionnaires, and results of the nerve conduction study were assessed at baseline. Treatment success was defined in this study as the absence of symptom recurrence within the entire follow-up period. RESULTS: The treatment success rate was 45% (n = 18) after an average follow-up of 16 months. Overall, 11 patients (28%) underwent carpal tunnel release on an average of 11 months after steroid injection. The large-CSA group showed a significantly worse grade of electrodiagnostic testing at baseline than did the small-CSA group; however, there was no significant difference in final Boston Carpal Tunnel Questionnaires symptom score (1.7 vs 1.8, respectively) and the rate of continued treatment success at the last follow-up (42% vs 50%, respectively). The proportions of patients who required carpal tunnel decompression were 29% and 25% in the small-CSA and large-CSA groups, respectively. CONCLUSIONS: Local steroid injection for carpal tunnel syndrome has an overall success rate of 45% after a mean follow-up of 16 months. Preinjection CSA was not associated with whether the steroid injection was considered successful. This indicates that increased median nerve CSA does not preclude the possibility of symptomatic relief after a local steroid injection. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Ultrasonographic Measurement of Median Nerve Cross-Sectional Area in Evaluating Carpal Tunnel Release Outcomes.

PURPOSE: Earlier research has explored carpal tunnel release (CTR) surgery outcomes using electrodiagnostic tests (EDX). However, evaluation of the median nerve before and after CTR by ultrasound (US) is understudied. This study aimed to establish the outcomes of CTR by EDX and US, and examine the correlation between the clinical improvement and US after CTR. METHODS: The sample consisted of 172 wrists that underwent CTR. Pain was assessed using the visual analog scale (VAS). The Boston Carpal Tunnel Syndrome Questionnaire (BCTQ), including the symptom severity and function subscales, was applied before and 3 months after CTR. The proximal and distal cross-sectional areas (CSAs) of the median nerve were measured using US, and EDX was performed before and 3 months after CTR. RESULTS: Patients had mean preoperative and postoperative VAS scores of 7.7 ± 1.2 and 1.7 ± 1.2, respectively. The mean preoperative and postoperative proximal CSA measurements were 16.4 ± 4.5 mm2 and 12.1 ± 3.9 mm2, respectively. The mean preoperative and postoperative distal CSA measurements were 13.6 ± 3.7 mm2 and 11.0 ± 3.1 mm2, respectively. A significant improvement was observed in VAS, BCTQ, and EDX 3 months after CTR. A weak, positive correlation was observed between the improvement in the BCTQ symptom severity and function subscales and CSAs following CTR. CONCLUSIONS: The results of this study demonstrate that preoperative median nerve CSA values may be used in evaluating CTR outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Lacertus syndrome: a ten year analysis of two hundred and seventy five minimally invasive surgical decompressions of median nerve entrapment at the elbow.

PURPOSE: This study aims to assess the clinical presentation and surgical outcomes of lacertus syndrome (LS) and concomitant median nerve entrapments. METHODS: A retrospective study of prospectively collected data was conducted on patients undergoing lacertus release (LR) from June 2012 to June 2021. Available DASH (Disability of the Arm Shoulder Hand questionnaire) scores and post-operative Visual Analogue Scale (VAS) of pain, numbness, subjective satisfaction with surgical outcome, and intra-operative return of strength were analyzed. RESULTS: Two-hundred-seventy-five surgical cases were identified of which 205 cases (74.5%) underwent isolated LR, and 69 cases (25.1%) concomitant lacertus and carpal tunnel release. The three most common presenting symptoms in LS patients were loss of hand strength (95.6%), loss of hand endurance/fatigue (73.3%), and forearm pain (35.4%). Numbness in the median nerve territory of the hand was found in all patients with combined LS and carpal tunnel syndrome. Quick-DASH significantly improved (pre-operative 34.4 (range 2.3-84.1) to post-operative 12.4 (range 0-62.5), p < 0.0001) as did work and activity DASH (p < 0.0001). The postoperative VAS scores were pain VAS 1.9 and numbness VAS 1.8. Eighty-eight percent of patients reported good/excellent satisfaction with the surgical outcome. Intra-operative return of strength was verified in 99.2% of cases. CONCLUSION: LS is a common median nerve compression syndrome typically presenting with loss of hand strength and hand endurance/fatigue. Minimally invasive LR immediately restores hand strength, significantly improves DASH scores, and yields positive outcomes regarding VAS pain, numbness, and subjective satisfaction with surgery in patients with proximal median nerve entrapment at a minimum six month follow-up.

Long-Term Outcome of 118 Acute Total Brachial Plexus Injury Patients Using Free Vascularized Ulnar Nerve Graft to Innervate the Median Nerve.

BACKGROUND: The restoration of finger movement in total brachial plexus injuries (BPIs) is an ultimate challenge. Pedicled vascularized ulnar nerve graft (VUNG) connecting a proximal root to distal target nerves has shown unpredictable outcomes. We modified this technique by harvesting VUNG as a free flap to reinnervate median nerve (MN). We analyzed the long-term outcomes of these methods. METHODS: From years 1998 to 2015, 118 acute total brachial plexus patients received free VUNG to innervate the MN. Patients were followed up at least 5 years after the initial surgery. Donor nerves included the ipsilateral C5 root (25 patients) or contralateral C7 root (CC7 = 93 patients). Recovery of finger and elbow flexion was evaluated with the modified Medical Research Council system. Michigan Hand Score and Quick-DASH were used to represent the patient-reported outcomes. RESULTS: For finger flexion, ipsilateral C5 transfer to MN alone yielded similar outcomes to MN + MCN (musculocutaneous nerve), while CC7 had significantly better finger flexion when coapted to MN alone than to MN + MCN. Approximately 75% patients were able to achieve finger flexion with nerve transfer alone. For elbow flexion, best outcome was seen in the ipsilateral C5 to MCN and MN. CONCLUSION: In acute total BPI, the priority is to identify the ipsilateral C5 root to innervate MN, with concomitant innervation of MCN to establish the best outcomes for finger and elbow flexion. CC7 is more reliable when used to innervate one target (MN). LEVEL OF EVIDENCE: III.

[Rare variant of median nerve compression: compression by brachial artery false aneurysm combined with carpal tunnel syndrome. Case report and literature review]. / Redkii variant kompressii sredinnogo nerva: kompressiya lozhnoi anevrizmoi plechevoi arterii v sochetanii s sindromom karpal'nogo kanala. Sluchai iz praktiki i obzor literatury.

BACKGROUND: The authors present severe compression of the median nerve by iatrogenic false aneurysm of the brachial artery combined with carpal tunnel syndrome. MATERIAL AND METHODS: An 81-year-old woman developed acute anesthesia of fingers I-III of the left hand, impaired flexion of the thumb and forefinger, swelling of the hand and forearm, local pain in postoperative period after angiography. The patient was previously followed-up for transient numbness in both hands for 2 years with a diagnosis of carpal tunnel syndrome. Electroneuromyography and ultrasound of the median nerve at the level of shoulder and forearm were carried out. We visualized a pulsatile lesion with Tinel's sign within the elbow (false aneurysm of the brachial artery). RESULTS: Resection of brachial artery aneurysm and neurolysis of the left median nerve were followed by regression of pain syndrome and improvement of motor function of the hand. CONCLUSION: This case demonstrates a rare variant of acute high compression of the median nerve after diagnostic angiography. This situation should be considered in differential diagnosis with classical carpal tunnel syndrome.

A new method to quantify innervation of the ulnar intrinsic hand muscles by the anterior interosseous nerve in Martin-Gruber anastomosis and nerve transfer surgery.

INTRODUCTION/AIMS: It is important to quantify the amount of crossover innervation from the anterior interosseous nerve (AIN) through Martin-Gruber anastomosis (MGA) particularly in patients with high ulnar nerve injury who undergo nerve transfer surgery. The objective of this study is to describe a novel electrophysiological method for quantifying innervation from the AIN that can be done using conventional nerve conduction study setup and commonly available software for analysis. METHODS: Seven subjects with MGA and nine patients who had undergone AIN to ulnar nerve transfer underwent conventional motor nerve conduction studies. Recording was done over the hypothenar and first dorsal interosseous muscles while stimulating the median and ulnar nerves at the wrist and elbow. Datapoint-by-datapoint subtraction of the compound muscle action potentials evoked at the elbow and wrist was performed after they had been onset-aligned. The results were compared to the collision technique and innervation ratio method. RESULT: Results from the digital subtraction method were highly correlated with the collision technique (r = 0.96, p < 0.05). In contrast, its correlation with the innervation ratio method is substantially lower. DISCUSSION: In comparison to previously described techniques, the digital subtraction method has a number of practical advantages. It uses conventional nerve conduction study setup, and the added step of digital alignment and subtraction can be done through commonly available software. With the increasing use of nerve transfer surgery in severe high ulnar nerve injury, this could be a useful method to identify the presence of MGA prior to surgery and for evaluating nerve recovery following surgery.

Comparison of the Therapeutic Effect of the Mini-Open Incision and Conventional Open Neurolysis of the Median Nerve for Carpal Tunnel Syndrome.

Objective: The aim of this study was to compare the therapeutic effects of the mini-open incision and conventional open surgery for carpal tunnel syndrome (CTS). Methods: The clinical data of 52 patients with CTS treated at the First Affiliated Hospital of the University of Science and Technology of China from October 2020 to February 2022 were retrospectively analyzed. The patients were divided into the conventional open surgery group (28 cases) and the mini-open incision group (24 cases) according to different surgical incisions applied. The incision length, operation time, time until postoperative return to work, and complications were observed in the two groups. The Visual Analog Scale (VAS) for pain at one day, one month, and three months after surgery and the Boston Carpal Tunnel Questionnaire scores before, at one month, and at three months after surgery were compared between the two groups. Results: The incision length, operation time, and time until return to work in the mini-open incision group were all shorter than those in the conventional open surgery group (2.58 ± 0.35 vs. 7.32 ± 0.61 cm, 18.67 ± 2.62 vs. 29.46 ± 3.42 min, and 5.33 ± 1.40 vs. 13.86 ± 2.70 d, respectively), and differences were statistically significant (P < 0.05 in all). The VAS scores in the mini-open incision group were lower than those in the conventional open surgery group at one day and one month after surgery, while the difference in the VAS scores at three months after surgery was not statistically significant between the two groups. There was no statistically significant difference in neurological recovery between the two groups at postoperative follow-ups (P > 0.05). The incidences of postoperative scar hyperplasia and scar pain were higher in the conventional open surgery group than those in the mini-open incision group, and differences were statistically significant (P < 0.05 in both). Conclusion: Mini-open incision surgery for CTS was a safe and reliable procedure with a precise therapeutic effect, minimal surgical trauma, and high postoperative comfort for patients and could achieve enhanced recovery. Trial Registration. This trial is registered with ChiCTR2200064631.

Palmar Creases and Their Implication on Carpal Tunnel Surgery.

BACKGROUND: A thorough knowledge of normal and variant anatomy of the wrist and hand is fundamental to avoiding complications during carpal tunnel release. The purpose of this study was to document variations of the surface anatomy of the hand to identify a safe zone in which the initial carpal tunnel incision could be placed. The safe zone was identified as the distance between the radial side of hook of hamate and the ulnar edge of the origin of the motor branch of the median nerve (MBMN). METHODS: Kaplan's cardinal line and other superficial markers were used to estimate the size of the safe zone, in accordance to prior published anatomical studies. The presence of a longitudinal palmar crease (thenar, median, or ulnar creases) within the safe zone was recorded. RESULTS: Of the 150 participants (75 male, 75 female) examined, the average safe zone widths were 10.85 (right) and 10.28 (left) mm. In all the hands examined, 86.33% of the safe zones (259 of 300) contained a longitudinal palmar crease. In the White population (n = 50), the average safe zone widths were 11.49 (right) and 10.01 (left) mm; in the African American population (n = 50), the average safe zone widths were 12.27 (right) and 12.01 (left) mm; and in the Asian population (n = 50), the average safe zone widths were 8.79 (right) and 8.82 (left) mm. On overage, males had a larger safe zone width than females by 4.55 mm. CONCLUSIONS: Although there seems to be variability between race and sex with regard to safe zone width, finding 86.33% of longitudinal palmar creases within the safe zone suggests that, for most patients, the initial carpal tunnel surgery incision may be hidden within the palmar crease while minimizing the risk of motor branch of the median nerve injury. Overall, the safe zone width is on average up to 10.5 mm measured from the hook of the hamate along Kaplan's cardinal line.

Anatomic Variations and Malformations as Rare Causes of Median Nerve Compression in Adults: A Narrative Review.

OBJECTIVE: The median nerve can become compressed at multiple points in the arm, causing carpal tunnel-, pronator-, anterior interosseous-, or lacertus syndrome. Anatomical variations are potential reasons of persisting or recurrent symptoms of median nerve compression and are often recognized late. The objective of this study is to provide a comprehensive list of rare anatomical variations and malformations causing median nerve compression. METHODS: A total of 62 studies describing median nerve compression due to an anatomical structure in adults published from 2000 in English were included. The findings were: 35 tenomuscular, 16 vascular causes, and 4 cases with nerve involvement. Only 1 osseous and 18 combined anomalies caused compression. In 18 cases, the anomaly was found in the proximal forearm. RESULTS: In 44 cases, the median nerve was surgical released and 35 anomalies were completely resected. Persistent or recurrent symptoms were present in 13 cases. During follow-up, 1 case of recurrence was reported.Standard operative option for median nerve compression consists of an open median nerve release. CONCLUSIONS: In case of persistent or recurrent carpal tunnel syndrome, unilateral symptoms, the presence of a palpable mass, manifestation of symptoms at young age and pain in the forearm or upper arm, the surgeon has to rule out the presence of an anatomical anomaly. Complete resection of the anomaly is not always necessary. The surgeon should be aware of potential anomalies to avoid inadvertent damage at surgery.

Median Nerve Injury in Ultrasound-Guided Hydrodissection and Corticosteroid Injections for Carpal Tunnel Syndrome.

PURPOSE: Permanent nerve damage after corticosteroid injection has been suggested when symptoms of median nerve injury (MNI) are irreversible. We assess the outcomes of MNI and their association with ultrasonography (US)-guided hydrodissection and the following corticosteroid injection for symptomatic carpal tunnel syndrome (CTS). METHODS: US-guided hydrodissection and the following corticosteroid injections were administered to 126 CTS patients. Occurrence of MNI, clinical data, and post-hydrodissection findings were evaluated. Post-hydrodissection findings included vascular injury during hydrodissection, altered echogenicity, reduced flattening ratio, and increased cross-sectional area of the MN at the inlet of the carpal tunnel (MN-CSA-Inlet) on ultrasonography after hydrodissection. The relevance of MNI with respect to these clinical data and findings was determined. The outcome was rated using Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores. RESULTS: Nine patients suffered MNI (incidence, 7.1 %) but improved significantly at follow-up. Clinical data and vascular injury during hydrodissection, altered echogenicity, and reduced flattening ratio after hydrodissection were unrelated to prolonged transient MNI (p > 0.05). MNI was significantly associated with increased CSA (p = 0.005). A CSA increase > 2 mm2 after hydrodissection yielded the greatest performance (0.979) for MNI in the receiver operating characteristic analysis. Decreases in BCTQ scores after injection did not differ significantly between groups with and without MNI (p > 0.05). CONCLUSION: MNI during hydrodissection may be reversible. MNI is indicated by an increase in MN-CSA-inlet immediately after hydrodissection.

Surgical Excision of a Thrombosed Persistent Median Artery in a Professional Hockey Player.

A persistent median artery is a rare anatomical variant found in approximately 10% of the population. Carpal tunnel syndrome due to a thrombosed persistent median artery is exceptionally rare. A 29-year-old professional hockey player presented with a 2 months history of hand pain and intermittent paresthesias without vascular symptoms. Magnetic resonance imaging and angiography demonstrated a 2-cm thrombosis in a persistent median artery at the level of the carpal tunnel, with otherwise normal vascular anatomy. He was treated with surgical excision of the thrombus and carpal tunnel decompression. The patient's symptoms resolved rapidly and he was able to return to sport without restrictions. Incidental imaging performed several months after surgery demonstrated a normal vascular pattern in the treated hand.

Post-traumatic entrapment of the median nerve in the ulno-humeral joint: Diagnosis, treatment and literature review.

BACKGROUND: The incidence of median nerve injuries in pediatric elbow dislocations is approximately 3% and avulsion of the open medial epicondylar epiphysis in the pediatric population is one predisposing factor that may explain this age predilection. These lesions can be difficult to diagnose in the acute phase because symptoms tend to be mild or delayed, consequently their management can be challenging and functional outcome poorer. METHODS: We present the case of an unrecognized median nerve entrapment in a 16-year-old boy with posterior dislocation of the elbow and a medial epicondyle fracture, treated initially with close reduction and open stabilization with a cannulated screw. Assessment is supported by a review of similar reported cases available in literature. RESULTS: We discuss the diagnostic approach and the surgical options that can be used for this type of injury. CONCLUSIONS: High clinical suspicion of entrapment is imperative in presence of signs of damage to the median nerve in the pediatric patient immediately after the reduction of an elbow dislocation. If diagnosis of entrapment is made the therapeutic choice between neurolysis and nerve graft depends on the lesion severity. In the presence of a Fourrier's type 4 lesion, neurolysis should be avoided, while nerve resection and grafting are recommended.