Ultrasound-guided minimally invasive thread release of Guyon's canal: initial experience in cadaveric specimens.

OBJECTIVE: Guyon's canal syndrome is caused by compression of the ulnar nerve at the wrist, occasionally requiring decompression surgery. In recent times, minimally invasive approaches have gained popularity. The aim of this study was to assess the efficacy and safety of ultrasound-guided thread release for transecting the palmar ligament in Guyon's canal without harming surrounding structures, in a cadaveric specimen model. METHODS: After ethical approval, thirteen ultrasound-guided thread releases of Guyon's canal were performed on the wrists of softly embalmed anatomic specimens. Cadavers showing injuries or prior operations at the hand were excluded. Subsequently, the specimens were dissected, and the outcome of the interventions and potential damage to adjacent anatomical structures as well as ultrasound visibility were evaluated with a score from one to three. RESULTS: Out of 13 interventions, a complete transection was achieved in ten cases (76.9%), and a partial transection was documented in three cases (23.1%). Irrelevant lesions on the flexor tendons were observed in two cases (15.4%), and an arterial branch was damaged in one (7.7%). Ultrasound visibility varied among specimens, but essential structures were delineated in all cases. CONCLUSION: Ultrasound-guided thread release of Guyon's canal has shown promising first results in anatomic specimens. However, further studies are required to ensure the safety of the procedure. RELEVANCE STATEMENT: Our study showed that minimally invasive ultrasound-guided thread release of Guyon's canal is a feasible approach in the anatomical model. The results may provide a basis for further research and refinement of this technique. KEY POINTS: • In Guyon's canal syndrome, the ulnar nerve is compressed at the wrist, often requiring surgical release. • We adapted and tested a minimally invasive ultrasound-guided thread release technique in anatomic specimens. • The technique was effective; however, in one specimen, a small anatomic branch was damaged.

Median nerve versus flexor tendons: visualization of median nerve level changes in the proximal carpal tunnel during wrist movement with dynamic high-resolution ultrasound.

Aim: The purpose of this prospective ultrasound study was to document dorso-palmar (vertical) displacement of the median nerve in relation to the superficial flexor tendons at the level of the carpal tunnel. Furthermore, the gliding patterns of the median nerve were characterized. The presence of vertical gliding was intended to serve as an additional bio-kinematic parameter of median nerve movement, and will be referred to as a 'level change'. Material and methods: In this study, a total of 32 healthy young individuals underwent dynamic high-resolution ultrasound examinations of both wrists. The neutral position, and maximum flexion and extension of the wrist had to be reached in active and passive movement. The gliding patterns were determined in relation to the superficial flexor tendons. When no vertical nerve gliding was observed, it was characterized as 'no level change'. Results: The presence of a level change prevailed in the healthy young cohort and was observed in 84% (27/32) of individuals during wrist flexion. The following gliding pattern was distinctively the most common: gliding of the entire nerve in between the flexor tendons in active but not in passive movement of the right and left wrists (13/27; 48%). The extent of vertical displacement was found to be associated with the gliding pattern (Kruskal-Wallis test). Conclusions: Movement in the carpal tunnel allows the median nerve to adapt to biomechanical stress. Dynamic ultrasound can demonstrate median nerve level changes in response to wrist movements. Furthermore, a typical gliding pattern was characterized. The presence of level change and gliding patterns were proposed as additional movement parameters during wrist flexion in healthy individuals.

Successful salvage via re-osseointegration of a loosened implant in a patient with transtibial amputation.

CASE DESCRIPTION: Osseointegration is a relatively new technique for prosthetic limb attachment that offers various improvements for patients with amputation and facilitates joint preservation. We present a case of implant loosening during rehabilitation in a patient with transtibial amputation that was successfully managed through a combination of measures, aiming to promote re-osseointegration of the implant. OBJECTIVES: Not much is known about structured management of adverse events after osseointegration. Septic or aseptic loosening is currently regarded as implant failure, prompting removal and possible re-implantation at a later stage. The objective of this case report was to evaluate the feasibility of salvaging a loosened implant. STUDY DESIGN: Case report. TREATMENT: A novel treatment approach was employed to enable renewed osseointegration of the implant. First, the bone-implant interface was disrupted and renewed through axial rotation and distal repositioning of the implant. Afterwards, extracorporal shockwave therapy and antibiotic treatment were administered. Prosthetic rehabilitation was then started anew. Regular follow-up x-rays and clinical evaluations were conducted, including standardized outcome tests. OUTCOMES: These combined measures led to a successful re-osseointegration of the implant. In a 21-month follow-up, the patient regained a stable and secure gait pattern, using his prosthesis every day for 15 hours and scoring above average on standardized outcome measures. CONCLUSION: This represents the first report of implant salvage after failed primary osseointegration. As the associated risks of this novel treatment are very low, investigations are warranted to evaluate this approach on a larger scale.

High-Resolution Ultrasonography of the Transverse Cervical Nerve.

The transverse cervical nerve (TCN) is a superficial cutaneous branch of the cervical plexus that innervates the skin of the anterolateral neck. Therefore, it is exposed to injury in anterolateral cervical surgery, which can cause neuropathic pain. To provide a method with which to relieve patients' pain, this study aimed to evaluate the possibility of visualization, diagnostic assessment and blockade of the TCN with high-resolution ultrasound (HRUS). HRUS with high-frequency probes (15-22 MHz), guided ink-marking and consecutive dissection on both sides in nine fresh cadaver necks (n = 18) was conducted. On both sides of 20 healthy volunteers (n = 40), the distances between the greater auricular nerve (GAN) and the TCN at the posterior border of the sternocleidomastoid muscle were measured. Finally, cases referred to HRUS examinations because suspected TCN lesions were assessed. The TCN was visible in all anatomic specimens and in healthy volunteers. Dissection confirmed HRUS findings in all anatomic specimens (100%). In healthy volunteers, the mean distance between the GAN and the TCN was 10.42 ± 3.20 mm. The median visibility, rated on a five-point Likert scale, was four, reflecting good diagnostic quality. There were six patients with visible abnormalities on HRUS. This study confirmed the reliable visualization of the TCN with HRUS in anatomic specimens, healthy volunteers and patients.

Surgery of True Recurring Median Carpal Tunnel Syndrome with Synovial Flap by Wulle Plus Integument Enlargement Leads to a High Patient's Satisfaction and Improved Functionality.

This prospective study was conducted to investigate electrophysiological qualities and patient's satisfaction of a synovial gliding tissue flap in treating true recurring carpal tunnel syndrome. In 14 patients (11 women, three men), 15 median nerves were included in this retrospective study. For all 15 nerves, motor and sensory nerve conduction velocity, compound muscle action potential, a Visual Analogue Scale-score (VAS-score) questionnaire and an adapted Levine-Test were evaluated pre- and postoperatively. All participants underwent operative neurolysis of the median nerve, which was then enwrapped by a synovial gliding tissue flap. Eleven procedures were completed by integument enlargement. Follow-up period was 12 months. Postoperatively, distal latency decreased significantly by 15.6%. Compound muscle action potential and sensory nerve conduction velocity did not improve significantly. VAS score regarding pain reduced highly significantly with 74.1%. The adapted Levine-Test function score improved highly significantly with 39.2%. The synovial gliding tissue flap lead to an excellent patient's satisfaction for treating true recurring carpal tunnel syndrome. Primary wound closure should be completed with integument enlargement if needed.

Novel Demonstration of the Anterior Femoral Cutaneous Nerves using Ultrasound.

PURPOSE: Neuropathy of the intermediate (IFCN) and medial femoral cutaneous nerve (MFCN) is a potential iatrogenic complication of thigh surgery and its diagnosis is limited. This study aimed to evaluate the possibility of the visualization and diagnostic assessment of the IFCN and MFCN with high-resolution ultrasound (HRUS). MATERIALS AND METHODS: In this study, HRUS with high-frequency probes (15 - 22MHz) was used to locate the IFCN and the MFCN in 16 fresh cadaveric lower limbs. The correct identification of the nerves was verified by ink-marking and consecutive dissections at sites correlating to nerve positions (R1 - 3), namely, the origin, the mid portion, and the distal portion, respectively. 12 cases with suspected IFCN and MFCN lesions referred to our clinic for HRUS examinations were also assessed. RESULTS: Anatomical dissection confirmed the correct identification of the IFCN in 16/16 branches at all of the different locations (100 %). MFCN was correctly identified at R1 + 3, in all cases (16/16; 100 %), and in 14/16 cases (88 %) at (R2). 12 cases of patients with IFCN and MFCN pathologies (all of iatrogenic origin) were identified. 9 instances of structural damage were visible on HRUS, and all pathologies were confirmed by almost complete resolution of symptoms after selective HRUS-guided blocks with 0.5 - 1 ml lidocaine 2 %. CONCLUSION: This study confirms that the IFCN and the MFCN can be reliably visualized with HRUS throughout the course of these nerves, both in anatomical specimens and in patients.

Special aspects of wrist arthritis management for SLAC and SNAC wrists using midcarpal arthrodesis: results of bilateral operations and conversion to total arthrodesis.

Although midcarpal wrist arthrodesis is recognized as a standard procedure to treat scapholuate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) of the wrist, little has been reported about patients with bilateral involvement and the number, cause, and results of failed cases requiring conversion to total wrist arthrodesis. This study investigated the results of 20 patients with bilateral procedures and of 22 patients who underwent total wrist fusion after failed midcarpal arthrodesis out of an overall group of 907 patients treated by this method during a 12-year period. Of these, 16 bilateral and 20 converted cases were reexamined after an average of 48 months and 42 months, respectively. Patients after bilateral midcarpal arthrodesis experienced a pain reduction by an average of 54% of the preoperative pain values at rest and by 56% at stress on the visual analog scale (scale range: 0 to 100) and from intolerable (3.7) to pain only during stress (1.9) on the verbal scale (scale range: I to 4). A mean arc of wrist extension and flexion of 53 degrees on the right and 49 of the left wrist was preserved. The mean DASH score was 45 points and 70% of the patients felt impaired only during certain activities. Total arthrodesis reduced pain in 18 of 20 reexamined wrists by 67% of the previous values after the failed partial arthrodesis at rest and by 46% at stress on the visual analog scale andfrom intolerable pain (3.7) to pain only during stress (2.1) on the verbal scale. Seven of the 20 reexamined patients noted complete pain relief at rest and two also under stress conditions. The DASH score averaged 39 points. A mean Krimmer score of 46 points and a mean Buck-Gramcko and Lohman evaluation of 6 points represented a satisfactory result. Grip strength of the operated hand averaged 53% of the opposite side. Subjectively, 30% felt impaired only during certain activities, 55%felt considerably and 15% strongly limited in daily life. However, all but two patients were satisfied with the secondary total wrist fusion as pain was considerably reduced. Midcarpal arthrodesis reliably reduced pain and preserved valuable wrist mobility thus improving daily activity and quality of life also in bilateral carpal collapse. In the rare cases when midcarpal arthrodesis failed, total wrist arthrodesis markedly improved the complaints in most patients, but in contrast to other studies complete pain was seldom.

Minimal invasive treatment for scaphoid fractures using the cannulated herbert screw system.

Internal fixation of scaphoid fractures avoids the problems associated with prolonged plaster immobilization and, at the same time, allows an early return to activity for these mostly young patients.Internal fixation of the scaphoid is greatly facilitated by the use of specially designed headless bone screws, such as the Herbert bone screw, originally developed specifically for internal fixation of the scaphoid; furthermore, the advent of cannulated scaphoid screws has made closed (percutaneous fixation) stabilization of the scaphoid a reality. Indeed, this method has now become the treatment of choice for the majority of acute scaphoid fracture, bringing with it all the advantages of internal fixation without the disadvantages of open surgery.However, the success of closed treatment is also dependent on an accurate assessment of the fracture, and for this reason, we now advocate the routine use of computed tomography preoperatively. Because of the complex, 3-dimensional shape of the scaphoid, simple x-rays alone are inadequate, whereas computed tomography, parallel to the long axis of the scaphoid, allows excellent visualization of the fracture and any associated deformity, which must be corrected at the time of surgery.We describe here our method of treating acute scaphoid fractures, and we report the outcome of minimally invasive fixation.