Us and Mri Neurography Assessment of Diagnostic Criteria in Patients With Carpal Tunnel Syndrome Using Electrophysiological Tests as Gold Standard: A Prospective Study

BackgroundPeripheral neuropathy evaluation depends mainly on physical examination, patient history, electrophysiological studies, with evoked potential abnormalities. High-resolution US has the advantage of being fast, non-invasive modality with nerve dynamic assessment allowing examination of long part of nerve. MR imaging serve better in examination of deeper nerves with higher contrast resolution. It shows great benefit in patient with atypical presentation, Equivocal diagnosis and suspicious of secondary cause and post-surgical relapse.MethodsThis study was conducted prospectively on 32 patients, presented with carpal tunnel syndrome diagnosed by electrophysiological tests. Superficial US of the wrist joint was done to all participants followed by MRI within 1 weeks of the US.We aimed to assess the measurements & criteria of both US & MRN in diagnosis of CTS, depending mainly on the three-measurement assessed by Buchberger et al., then to find the agreement between US & MR Neurography (MRN)ResultsUs proved to have higher rate of CTS prediction, the three main parameters CSA measurement, distal nerve flattening and flexor retinaculum bowing indices showed positive occurrence of 93.7%,59.4% &59.4% respectively. While we found that decreased nerve echotexture was positive in 90.6% of patients.Regarding MRI it showed less diagnostic ability when using CSA measurement as it was positive in 81.2% of patients, also distal tunnel nerve increased flattening and bowed flexor retinaculum positive results were slightly decreased to 56.2% for each. In contrast to high T2 signal of median nerve which was positive in 90.6% of patients.In agreement study, we found statically significant difference supporting US as the primary diagnostic modality of CTS depending mainly on the three measurement CSA, Flattening and bowing indices. Yet, for cases of secondary CTS and detection of underlying entrapping cause as well as innervated muscle early abnormality detection and better tissue characterization, MRI was better diagnostic modality with statistically significant difference. ConclusionsOur results proved that ultrasound examination can be used as first imaging modality after physician evaluation with comparable results to electrophysiological studies in evaluating CTS and try to find the cause. MRN examination came as second step in patients with suspected muscle denervation changes that could not be elicited by US or equivocal cases for detection of secondary cause in clinically suspected patient.

Supraretinacular endoscopic carpal tunnel release: A safe alternative method for treatment of carpal tunnel syndrome

Purpose: Supraretinacular endoscopic carpal tunnel release (SRECTR) is a technique in which an endoscope is inserted superficial to the flexor retinaculum through a subcutaneous tunnel. The benefits of this method include a clear view for the surgeon and absence of median nerve compression. Surgeons can operate with a familiar view of the flexor retinaculum and median nerve downward, similar to open surgery. This study aimed to investigate the learning curve for SRECTR, an alternate method for carpal tunnel release, and evaluate its complications and the functional outcomes using a disposable commercial kit. Methods: We examined the open conversion rates and complications associated with SRECTR in 200 consecutive patients performed by two surgeons. We compared the operative time operated by a single surgeon. We evaluated outcomes in 191 patients according to Kelly’s grading system. Patients’ mean follow-up period was 12.7 months. Results: Nine patients required conversion to open surgery. There were no injuries to the nerves and tendons and no hematoma or incomplete dissection of the flexor retinaculum. The operative times varied between 11 and 34 minutes. We obtained the following results based on Kelly’s grading of outcomes: excellent in 116, good in 59, fair in 13, and poor in 3 patients. Conclusions: We found no patients with neurapraxia, major nerve injury, flexor tendon injury, superficial palmar arch injury, and hematoma. Although there was a learning curve associated with SRECTR, we performed 200 consecutive cases without neurovascular complications. This method may be a safe alternative to minimally invasive carpal tunnel surgery.

The Flexor Retinaculum Connects the Surrounding Structures into the Medial Ankle Complex

This study aimed to prove the hypothesis that the medial structures of the ankle are interconnected through the flexor retinaculum’s projections. We conducted a retrospective re-evaluation of 132 MRI examinations of the ankle joint from 57 females and 75 males with an age range of 18–65 and a mean age of 35 years. The correlation between the presence of connections between the flexor retinaculum and the deltoid ligament, the spring ligament, the inferior extensor retinaculum, the paratenon, the fibulotalocalcaneal ligament, the fascia covering the abductor hallucis, and the flexor fibrous sheath were studied. The most common connections of the flexor retinaculum were to the deltoid ligament (97%), the fibulotalocalcaneal ligament (84.1%), and the flexor fibrous sheath (83.3%). Interconnection between the flexor retinaculum and the deltoid ligament correlated with the presence of connections between the flexor retinaculum and the inferior extensor retinaculum, the paratenon, and the spring ligament. Side difference was noticed in connections to the flexor fibrous sheath, the deltoid ligament, the fascia on the abductor hallucis, and the paratenon (p < 0.05). The flexor retinaculum formed a more complex anatomical unit with adjacent structures.

Effect of Lateral Sliding Calcaneus Osteotomy on Tarsal Tunnel Pressure

Background: Lateral sliding calcaneus osteotomies are common procedures to correct hindfoot varus deformities. Shifting the calcaneal tuberosity laterally (lateralization) can lead to tarsal tunnel pressure increase and tibial nerve palsy. The purpose of this cadaveric biomechanical study was to investigate the correlation of lateralization and pressure increase underneath the flexor retinaculum. Methods: The pressure in the tarsal tunnel of 12 Thiel-fixated human cadaveric lower legs was measured in different foot positions and varying degrees of calcaneal lateralization. Results: The mean pressure increased from plantarflexion (PF) to neutral position (NP) and from NP to hindfoot dorsiflexion (DF), and with increasing amounts of lateralization of the calcaneal tuberosity. The mean baseline pressure in PF was 1.5, in NP 2.2, and in DF 6.5 mmHg and increased to 8.1 in PF, 18.4 in NP, and 33.1 mmHg with 12 mm of lateralization. The release of the flexor retinaculum significantly lowered the pressure. Conclusion: Increasing pressures were found in the tarsal tunnel with increasing lateralization of the tuberosity and with both dorsiflexion and plantarflexion of the ankle. Clinical Relevance: A pre-emptive release of the flexor retinaculum for a lateralization of the calcaneal tuberosity of more than 8 mm should be considered, especially if specific patient risk factors are present. No tibial nerve palsy should be expected with 4 mm of lateralization.

Role of High-Resolution Ultrasonography in Evaluation of Median Nerve and Thickness of Flexor Retinaculum in Patients with Hypothyroidism

Objectives: To determine the role of high resolution ultrasonography in evaluation of cross sectional area, maximum nerve fascicle thickness and thickness/width ratio of the median nerve and flexor retinaculum thickness in patients with hypothyroidism and to correlate it with the healthy volunteers. Material and Methods: A prospective study was conducted from February 2018 to October 2019 on 62 patients which included 32 clinically proven cases of hypothyroidism and 30 healthy volunteers. High resolution ultrasonography was performed using high frequency linear probes. Results: The most affected parameter was cross sectional area of median nerve at three levels, inlet/outlet ratio of CSA of the median nerve and thickness of flexor retinaculum in hypothyroidism patients in correlation with healthy volunteers. These parameters showed statistically significant p values. Maximum nerve fascicle thickness and thickness/width ratio of the median nerve showed no statistical significance in hypothyroid patients in correlation with healthy volunteers. Conclusion: High-resolution ultrasonography plays an important role in evaluating the changes occuring in cross sectional area of the median nerve, its inlet/outlet CSA ratio and flexor retinaculum thickness in hypothyroidism patients as correlated with the healthy volunteers.

A Study on Distribution and Mode of Origin of Median Nerve and its Relation to the Flexor Retinaculum

Introduction:The precise knowledge of level of origin of muscular branches of median nerve are essential in free muscular transfers to restore the mobility of fingers after trauma and to understand the various presentations of nerve entrapment. The anatomical knowledge and variations of recurrent nerve is important to prevent the complications during the release of transverse carpal ligament.Aim & Objectives: To study the points of origin of muscular branches with respect to IEL and number of branches to muscles of forearm and also learn the mode of origin of recurrent nerve and its relation to the flexor retinaculum.Subjects and Methods:Dissection 40 upper limbs procured from embalmed cadavers of Dr. VRK Women’s Medical College, Hospital and Research Centre, Hyderabad, for the study.Results:The mean of point of origin of NPT was 1.21 cm proximal and 1.20 cm distal to IEL whereas for NFCR, NPL, NFDS and AIN nerve it was 2.12 cm, cm, 4.54 cm and 3.29 cm distal to IEL respectively. The number of branches to muscles of forearm varied from 1 to 3. The recurrent nerve was arising from lateral and intermediate branches of median nerve in 39 (97.5%) and 1 specimens (6%) respectively. Its relationship with flexor retinaculum was extra ligamentous in 33 specimens (82.5%) and transligamentous in 7 specimens (17.5%). It innervated APB, FPB and OP in 19 specimens (47.5%), only APB, FPB in 16 specimens (45%) and only APB, OP in 3 specimens (7.5%).Conclusion:All the muscular branches of median nerve were arising predominantly distal to IEL except nerve to pronator teres. The number of branches varied from 1 to 3. In majority of the specimens, the recurrent nerve was arising from the lateral terminal branch of median nerve and its relation with flexor retinaculum was extraligamentous.

Trigger Digit Incidence After Carpal Tunnel Release: Reconstruction in Elongated Position Versus Traditional Carpal Tunnel Release

Background: The development of trigger digit after carpal tunnel syndrome release surgery has been widely reported. Lluch described reconstruction of the flexor retinaculum in elongated position to prevent such complication. Methods: We conducted a retrospective review to determine whether patients who undergo reconstruction in elongated position of the flexor retinaculum have a lower incidence of trigger digit postoperatively. In total, 1050 patients were included, 865 of whom had undergone traditional carpal tunnel release and 185 flexor retinaculum reconstruction. Results: No differences were found in the incidence of trigger digit after surgery (8.7% of the patients who underwent traditional release vs 11.9% in the reconstruction group). Neither difference was found when comparing mean time with the development of trigger digit. Conclusions: In the absence of randomized long-term studies comparing traditional release and reconstruction in elongated position after carpal tunnel release, given our results, we see no reason to favor reconstruction over standard carpal tunnel release as a means to prevent postoperative triggering of digits.