An ultrasonographic and anatomical study of carpal tunnel, with special emphasis on the safe zones in percutaneous release

[Translated article] Percutaneous ultrasound-guided section of the transverse carpal ligament vs. open surgery for the surgical treatment of carpal tunnel syndrome (CTS)

BACKGROUND AND OBJECTIVE

The gold standard of carpal tunnel syndrome (CTS) treatment is the section of the transverse carpal ligament, the most common technique being the palmar cutaneous incision. Percutaneous techniques have been developed, although their risk/benefit ratio remains controversial.

OBJECTIVE

To analyse the functional outcome of patients undergoing CTS percutaneously ultrasound-guided and compare it with those of open surgery.

MATERIAL AND METHOD

Prospective observational cohort study of 50 patients undergoing CTS (25 percutaneous with WALANT technique and 25 by open surgery with local anaesthesia and tourniquet). Open surgery was performed using a short palmar incision. The percutaneous technique was performed anterograde using the Kemis H3® scalpel (Newclip). A preoperative and postoperative assessment was performed at 2 weeks, 6 weeks and 3 months. Demographic data, presence of complications, grip strength and Levine test score (BCTQ) were collected.

RESULTS

The sample consists of 14 men and 36 women with a mean age of 51.4 years (95% CI: 48.4-54.5). Percutaneous technique was performed anterograde using the Kemis H3® scalpel (Newclip). All patients improved from their CTS clinic without obtaining statistically significant differences in BCTQ score, nor in the presence of complications (p>0.05). Patients operated on percutaneously recovered faster grip strength at 6 weeks, but it was similar in the final review.

CONCLUSIONS

In view of the results obtained, percutaneous ultrasound-guided surgery is a good alternative for the surgical treatment of CTS. Logically, this technique requires its learning curve and familiarisation with the ultrasound visualisation of the anatomical structures to be treated.

Percutaneous ultrasound-guided section of the transverse carpal ligament vs open surgery for the surgical treatment of carpal tunnel syndrome (CTS)

BACKGROUND AND OBJECTIVE

The gold standard of carpal tunnel syndrome (CTS) treatment is the section of the transverse carpal ligament, the most common technique being the palmar cutaneous incision. Percutaneous techniques have been developed, although their risk/benefit ratio remains controversial.

OBJECTIVE

To analyze the functional outcome of patients undergoing CTS percutaneously ultrasound-guided and compare it with those of open surgery.

MATERIAL AND METHOD

Prospective observational cohort study of 50 patients undergoing CTS (25 percutaneous with WALANT technique and 25 by open surgery with local anesthesia and tourniquet). Open surgery was performed using a short palmar incision. The percutaneous technique was performed anterograde using the Kemis® H3 scalpel (Newclip). A preoperative and postoperative assessment was performed at 2 weeks, 6 weeks and 3 months. Demographic data, presence of complications, grip strength and Levine test score (BCTQ) were collected.

RESULTS

The sample consists of 14 men and 36 women with a mean age of 51.4 years (95% CI: 48.4-54.5). Percutaneous technique was performed anterograde using the Kemis® H3 scalpel (Newclip). All patients improved from their CTS clinic without obtaining statistically significant differences in BCTQ score, nor in the presence of complications (p> 0.05). Patients operated on percutaneously recovered faster grip strength at 6 weeks, but it was similar in the final review.

CONCLUSIONS

In view of the results obtained, percutaneous ultrasound-guided surgery is a good alternative for the surgical treatment of CTS. Logically, this technique requires its learning curve and familiarization with the ultrasound visualization of the anatomical structures to be treated.

Utilidad de la ecografía en la cirugía de la mano: Parte II

En los últimos años, con los avances técnicos en la ecografía, aumentó la calidad de las imágenes, lo que ha permitido a los cirujanos mejorar su capacidad de evaluar la mano y la muñeca. Las infiltraciones ecoguiadas en cirugía de mano son más precisas y seguras en comparación con las infiltraciones sin el uso de ecografía. El desarrollo de la técnica de ecografía y de transductores de alta resolución nos ayuda a realizar procedimientos ecoguiados, como el tratamiento del dedo en gatillo, la liberación del síndrome del túnel carpiano, y la aponeurotomía en la enfermedad de Dupuytren. El objetivo de este trabajo es describir las técnicas ecográficas en el tratamiento de las patologías de la mano y el estado del arte de las cirugías ecoguiadas de la mano y sus resultados.

Thenar and Hypothenar Muscle Coverage on the Transverse Carpal Ligament

Background  The purpose of the study was to examine the coverage of thenar and hypothenar muscles on the transverse carpal ligament (TCL) in the radioulnar direction through in vivo ultrasound imaging of the carpal tunnel. We hypothesized that the TCL distance covered by the thenar muscle would be greater than that by the hypothenar muscle, and that total muscle coverage on the TCL would be greater than the TCL-alone region. Methods  Ultrasound videos of human wrist were collected on 20 healthy subjects. Automated algorithms were used to extract the distal cross-sectional image of the trapezium-hamate level. Manual tracing of the anatomical features was conducted. Results  Thenar muscles covered a significantly larger distance (11.9 ± 1.8 mm) as compared with hypothenar muscles (1.7 ± 0.8 mm) ( p  < 0.001). The TCL covered by thenar and hypothenar muscles was greater than the TCL-alone length ( p  < 0.001). The thenar and hypothenar muscle coverage on the TCL, as normalized to the total TCL length, was 61.0 ± 7.5%. Conclusions  More than 50% of the TCL at the distal carpal tunnel is covered by thenar and hypothenar muscles. Knowledge of muscular attachments to the TCL improves our understanding of carpal tunnel syndrome etiology and can guide carpal tunnel release surgery.

Safe Zones for Percutaneous Carpal Tunnel Release

Carpal tunnel release (CTR) is an effective procedure used in open, endoscopic, or ultrasound-guided methods. The complications are rare but potentially devasting. Most complications come from errors related to intraoperative technique, especially in the minimally invasive approach. An understanding of the "safe zones" is essential to perform percutaneous CTR safely. This article reviews the anatomy of safe zones and the ultrasound-guided CTR (UCTR) techniques in an attempt to prevent intraoperative complications. In strict accordance with the concepts of safe zones, UCTR is an effective and reliable procedure. Substantial experience for ultrasound-guided injection and surgery is required.

Ultrasound (US) Changes in the Median Nerve Cross-Sectional Area After Microinvasive US-Guided Carpal Tunnel Release

OBJECTIVE

To document changes in the median nerve cross-sectional area (CSA) in the proximal carpal tunnel region after ultrasound (US)-guided carpal tunnel release (CTR).

METHODS

Prospective data were collected on 23 consecutive patients (37 wrists) treated with US-guided CTR by the primary author using the same office-based microinvasive technique. Ultrasound was used to measure the largest CSA of the median nerve in the proximal carpal tunnel region both preoperatively and postoperatively. The primary outcome measure was the change in the preoperative versus 6- to 10-week postoperative median nerve CSA.

RESULTS

The mean CSA of the median nerve decreased from 16.08 to 12.75 mm² at 6 to 10 weeks after US-guided CTR (P < .001). During the same period, the mean Boston Carpal Tunnel Questionnaire (BCTQ) symptom score decreased from 3.23 to 1.67 (P < .001), and mean BCTQ functional score decreased from 2.49 to 1.47 (P < .001), both exceeding minimal clinically important differences. Although the primary end point was the median nerve CSA at 6 to 10 weeks, statistically significant reductions in the median nerve CSA, as well as BCTQ scores, were also observed as early as 2 to 4 weeks after US-guided CTR (median nerve CSA, 12.40 mm² ; BCTQ symptom score, 2.00; BCTQ functional score, 1.75; all P ≤ .03).

CONCLUSIONS

To our knowledge, this investigation was the largest to date examining changes in the proximal median nerve CSA after US-guided CTR. Statistically significant reductions in the proximal median nerve CSA were observed within 6 to 10 weeks after ultrasound-guided CTR. These reductions were similar to those previously reported for open and endoscopic CTR and validate the ability of US-guided CTR to relieve median nerve compression.

Clinical Results of Ultrasound-Guided Carpal Tunnel Release Performed by a Primary Care Sports Medicine Physician

OBJECTIVES

The purpose of this study was to determine the safety and efficacy of ultrasound-guided carpal tunnel release (USCTR) in a consecutive group of patients treated by a single primary care sports medicine physician.

METHODS

The study group consisted of 35 USCTRs performed on 22 consecutive patients for whom clinical outcomes were available before USCTR and at 1 to 2 weeks, 1 month, and 3 months after USCTR. All procedures were performed by the same operator using a single USCTR technique. Outcomes included complications, Quick Disabilities of the Arm, Shoulder, and Hand scores, Boston Carpal Tunnel Questionnaire symptom severity and functional status scores, and a 5-point global satisfaction score.

RESULTS

The 22 patients included 13 female and 9 male patients (ages 31-82 years). Eleven patients (22 wrists) had bilateral simultaneous USCTRs; 2 patients (4 wrists) had staged bilateral USCTRs; and 9 patients had unilateral USCTRs. No complications occurred in any patient. Statistically and clinically significant reductions in Quick Disabilities of the Arm, Shoulder, and Hand scores and Boston Carpal Tunnel Questionnaire symptom severity and functional status scores occurred by 1 to 2 weeks after USCTR (mean 1- to 2-week changes, -29.23, -1.74, and -1.18, respectively), and further improvements occurred during the 3-month follow-up period (mean 3-month changes, -51.11, -2.29, and -1.91; P < .0001 for all values versus before USCTR). Mean global satisfaction scores at 1 to 2 weeks and 3 months were 4.63 and 4.66.

CONCLUSIONS

Ultrasound-guided CTR is a safe and effective procedure that can be performed by an experienced primary care sports medicine physician and typically results in significant improvements within the first 2 weeks after the procedure. Furthermore, bilateral simultaneous USCTRs are feasible and may provide significant advantages for patients who are candidates for bilateral CTRs.

Ultrasound-guided percutaneous release of the carpal tunnel: comparison of the learning curves of a senior versus a junior operator. A cadaveric study

OBJECTIVE

The purpose was to evaluate, in a cadaveric cohort, the feasibility and the learning curve of ultrasound-guided percutaneous carpal tunnel release.

MATERIALS AND METHODS

Fourteen carpal tunnel releases were carried out on unembalmed cadavers by a senior and a junior radiologist. Procedures were realized with an 18-MHz linear probe. An anatomical evaluation was first performed using ultrasound to detect any anatomical variant. After hydrodissection of the carpal tunnel with lidocaine, a 3-mm hook knife was introduced into the security zone to perform a retrograde section of the transverse carpal ligament (TCL) under ultrasound guidance. Anatomical dissection was performed for each wrist. The main evaluation criterion was the complete TCL section. The procedure duration (minutes), skin incision size (millimeters), the integrity of the median nerve, thenar motor branch, and palmar vascular arch were also evaluated.

RESULTS

The senior operator was able to perform a complete release after training on three specimens and the junior operator after four specimens (p > 0.05). In most of the cases when complete release was not achieved, it was due to an incomplete section of the distal TCL (10 mm missing section on average). Mean duration time of procedure was 14 min (11 min for the senior versus 17 min for the junior, p > 0.05). Damage of neither the median nerve nor the vascular structure was observed. Mean size of the skin incision was 3 mm.

CONCLUSION

The ultrasound-guided percutaneous release of the carpal tunnel is demonstrated to be a procedure with a rapid learning curve.

Ultrasound-guided percutaneous carpal tunnel release in patients on hemodialysis: early experiences and clinical outcomes

Purpose: The purpose of the current study was to evaluate the effectiveness of ultrasound-guided percutaneous carpal tunnel release in hemodialysis patients with carpal tunnel syndrome.

Methods: From February 2009 to April 2013, a prospective review of 113 consecutive cases of ultrasound-guided percutaneous carpal tunnel release was carried out in 84 hemodialysis patients. Results were analyzed by clinical subjective scale, two self-administered questionnaires, and functional evaluations at seven time points (1 week and 1, 3, 6, 12, 18, and 24 months).

Results: Satisfactory symptom improvement in patients was 82%, 80%, 86%, 89%, 90%, 91%, and 90% at 1 week and 1, 3, 6, 12, 18, and 24 months postoperatively, respectively. Moderate pain was suffered in 11.5% of patients within 1 week, 8.8% within 1 month, 2.7% within 3 months, and none after 12 months postoperatively. Static two-point discrimination and Semmes–Weinstein monofilament examinations presented significant improvements after 1 week and 1 month postoperatively and with time. Postoperative grip power demonstrated recovery and a significant increase after 3 and 6 months postoperatively. Three-jaw chuck-pinch strength showed significant increase after 1 month postoperatively. There were no operative complications.

Conclusion: Ultrasound-guided percutaneous carpal tunnel release is an effective and safe procedure in hemodialysis patients with carpal tunnel syndrome. The advantages include a less invasive procedure, no tourniquet needed, only limited infiltration anesthesia, minimal soft-tissue exploration, and relatively short operation time. Our data suggest this technique can reliably relieve clinical symptoms, with early restoration of grip and pinch strength.

Minimally Invasive Ultrasound-Guided Carpal Tunnel Release: Preliminary Clinical Results

Ultrasound-guided carpal tunnel release was performed on 14 patients (18 wrists) using dynamic expansion of the transverse safe zone. Our patient population included able-bodied patients and those with impairments. The first 8 cases (12 wrists) underwent the procedure in an operating room, the remainder in an outpatient setting. No complications occurred, and all patients were able to immediately resume use of their hands without therapy. Improvements in the Quick Form of the Disabilities of the Arm, Shoulder, and Hand Index and Boston Carpal Tunnel Questionnaire at 3 months were comparable to results reported with mini-open and endoscopic release. Our results show that ultrasound-guided carpal tunnel release can be safely and effectively performed in an outpatient setting.

Anatomic Relationship Between the Hook of the Hamate and the Distal Transverse Carpal Ligament: Implications for Ultrasound-Guided Carpal Tunnel Release

OBJECTIVE

During ultrasound-guided carpal tunnel release, osseous landmarks may supplement direct visualization of the distal transverse carpal ligament (dTCL) to ensure a complete release. The purpose of this study was to determine the relationship between the apex of the hook of the hamate (aHH) and the dTCL within the transverse safe zone (TSZ) of the carpal tunnel.

DESIGN

Twenty unembalmed cadaveric specimens were dissected to determine the aHH-dTCL distance and the aHH-SPA distance (the distance between the aHH and the superficial palmar arch) at the ulnar and radial limits of the TSZ (the distance between the hook of the hamate or ulnar artery to the median nerve).

RESULTS

The aHH-dTCL distance averaged 11-12 mm across the TSZ (maximum, 18.2 mm), whereas the aHH-SPA distance was significantly greater on the radial side of the TSZ compared with the ulnar side (22.6 ± 3.6 mm vs. 14.0 ± 4.0 mm).

CONCLUSIONS

The dTCL lies approximately 11-12 mm distal to the aHH across the TSZ, with an upper limit of 18.2 mm. Along with direct sonographic visualization of the dTCL, the aHH can be used with other osseous landmarks to estimate the position of the dTCL during ultrasound-guided carpal tunnel release.

A Cadaveric Study for the Improvement of Thread Carpal Tunnel Release

PURPOSE

The thread carpal tunnel release (TCTR) technique has been improved and offers more precise control in dissecting thread placement. The purpose of this cadaveric study was to test the procedure operationally and verify the modified TCTR anatomically.

METHODS

Eleven unembalmed cadaver wrists underwent the transverse carpal ligament (TCL) release by using the modified TCTR technique. An experienced observer dissected each specimen and assessed for completeness of release under direct visual assessment. Injury to the superficial palmar aponeurosis (SupPA), the Berrettini and common digital nerve branches were also recorded as a secondary outcome.

RESULTS

Eleven out of 11 wrists (100%) underwent the modified TCTR with complete release of the TCL. All 11 wrists were released without damage to any vital neurovascular structure including the Berrettini branch and the common digital nerves. The SupPA remained intact in all 5 wrists performed with the preservation steps.

CONCLUSIONS

The modified TCTR technique demonstrated complete division of the TCL while protecting the SupPA as well as the Berrettini and common digital nerve branches.

CLINICAL RELEVANCE

The modified TCTR has the potential to offer a clinically safe and effective minimally invasive procedure for complete carpal tunnel release.

Ultra-Minimally Invasive Ultrasound-Guided Carpal Tunnel Release: A Randomized Clinical Trial

OBJECTIVES

The purpose of this study was to compare the outcomes of 1-mm ultra-minimally invasive ultrasound-guided carpal tunnel release and 2-cm blind mini-open carpal tunnel release.

METHODS

We conducted a single-center individual parallel-group controlled-superiority randomized control trial in an ambulatory office-based setting at a third-level referral hospital. Eligible participants had clinical signs of primary carpal tunnel syndrome and positive electrodiagnostic test results and were followed for 12 months. Independent outcome assessors were blinded. Patients were randomized by concealed allocation (1:1) by an independent blocked computer-generated list. The postoperative score on the Quick-Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire was the primary variable. Grip strength and time for discontinuation of oral analgesics, complete wrist flexion-extension, relief of paresthesia, and return to normal daily activities (including work) were assessed.

RESULTS

Ninety-two of 128 eligible patients were randomly allocated and analyzed. QuickDASH scores were 2.2 to 3.3 times significantly lower in the ultra-minimally invasive group for the first 6 months: 23.6 [95% confidence interval (CI), 20.5, 27.4] versus 52.6 [95% CI, 49.4, 57.0] at the first week and 4.09 [95% CI, 1.5, 7.1] versus 13.0 [95% CI, 9.4, 18.9] at 6 months. Return to normal daily activities occurred significantly sooner in the ultra-minimally invasive group: 4.9 [95% CI, 3.2, 6.5] versus 25.4 [95% CI, 18.2, 32.6] days.

CONCLUSIONS

Ultra-minimally invasive carpal tunnel release provides earlier functional return and less postoperative morbidity with the same neurologic recovery as mini-open carpal tunnel release for patients with symptomatic primary carpal tunnel syndrome.

Sonographic Visualization of Thenar Motor Branch of the Median Nerve: A Cadaveric Validation Study

BACKGROUND

The thenar motor branch (TMB) of the median nerve may be affected in carpal tunnel syndrome and can be injured during carpal tunnel surgery. Although ultrasound has been used to identify small nerves throughout the body, the sonographic evaluation of the TMB has not been investigated formally.

OBJECTIVE

To document the ability of ultrasound to visualize the TMB of the median nerve in an unembalmed cadaveric model.

DESIGN

Prospective laboratory investigation.

SETTING

Procedural skills laboratory at a tertiary medical center.

METHODS

On the basis of anatomical descriptions, dissection and clinical experience, a technique was developed to sonographically identify the presumed TMB of the median nerve at the distal carpal tunnel. A single, experienced examiner then identified the presumed TMB in 10 unembalmed, cadaveric upper limb specimens (4 right, 6 left) obtained from 9 donors (4 male, 5 female) ages 76-85 years with body mass indices of 18.2-29.5 kg/m² with both 12-3 MHZ and 16-7 MHz linear array transducers. The same examiner then injected 0.2-0.3 mL of diluted colored latex into and around the presumed TMB using direct ultrasound guidance. At a minimum of 24 hours postinjection, specimens were dissected under loupe magnification to determine the location of the latex injectate.

MAIN OUTCOME MEASURE

The location of latex injectate relative to the anatomically identified TMB.

RESULTS

A vertical, linear, hypoechogenic region was sonographically identified arising from the median nerve at the distal carpal tunnel in all 10 specimens and was hypothesized to represent the vertical segment of the TMB. Both transducers allowed identification of the TMB, although localization was subjectively facilitated by the higher frequency transducer. All 10 sonographically guided injections placed latex into and around the TMB of the median nerve, confirming that ultrasound had accurately identified the TMB.

CONCLUSIONS

Sonographic evaluation of the TMB of the median nerve is technically feasible and should be considered when clinically indicated. Further research and clinical experience is necessary to define the role of sonographic TMB imaging in the evaluation and management of patients with carpal tunnel syndrome.

LEVEL OF EVIDENCE

IV.

Ultrasonographically Guided Percutaneous Carpal Tunnel Release: Early Clinical Experiences and Outcomes

PURPOSE

To present the technique and results of ultrasonographically guided percutaneous carpal tunnel release (PCTR) in a consecutive series of patients with carpal tunnel syndrome (CTS).

METHODS

We used previously defined landmarks with the "safe zones," localization, estimated size, and extent of the transverse carpal ligament (TCL) for this prospective clinical study of 91 consecutive cases of carpal tunnel release treated with this technique. The follow-up consisted of 4 time points (1 week and 2, 6, and 12 months) and a final evaluation at an average of 22.5 months.

RESULTS

The sensory disturbances disappeared in 76.8%, 93.4%, 100%, and 100% of the patients at 1 week and 2, 6, and 12 months postoperatively, respectively. Moderate pain was experienced in 24.2% of patients within 1 week, in 6.6% of patients within 2 months, and in 1.1% of patients within 12 months after the operation. In the final evaluation, 2 hands were graded as unsatisfactory: one hand had moderate wrist pain without sensory disturbance, and one hand had a recurrence 14 months after the operation. There were no intraoperative or postoperative complications.

CONCLUSIONS

Ultrasonographically assisted PCTR is a safe and effective procedure, but it is technically demanding and requires substantial training to be proficient in its use.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

A non-scalpel technique for minimally invasive surgery: percutaneously looped thread transection of the transverse carpal ligament

PURPOSE

This study aims to develop an alternate technique for improving the surgical procedure of carpal tunnel release.

METHOD

The transverse carpal ligament is transected by utilizing a piece of thread looped percutaneously under the visualization of ultrasound. The procedure, the thread carpal tunnel release (TCTR), was performed on 34 hands of 20 patients. Self-administrated Levine-Katz questionnaire was used for assessing the symptom severity and functional status of the outcomes.

RESULTS

TCTR was performed in each case with no unintended consequences. The average duration for a procedure was 7 min, excluding time of preparation. Significant improvements in subjective sensibility were reported within 24 h, and sleep quality improved for all cases. There were no postoperative complications. The scores of questionnaire 3 months postoperatively were comparable to the literature controls.

CONCLUSION

TCTR is a safe and effective minimally invasive surgery performed under local anesthesia in a clinic-based procedure room and results in only one-needle entrance point at the wrist and one-needle exit point in the palm. The feature of the procedure includes the potentials of reduced risk of iatrogenic injury, reduced surgical cost, and reduced patient recovery time. The study has shown encouraging promise for optimizing the technique of carpal tunnel release, and more clinical trials are necessary to confirm the findings.

A cadaveric and preliminary clinical study of ultrasonographically assisted percutaneous carpal tunnel release

The aim of this study was to assess the effectiveness and safety profile of a new technique for ultrasonographically assisted percutaneous carpal tunnel release. Experiments were performed on 40 hands in 20 cadavers. We first performed a detailed ultrasonographic examination and correlation study that included surgical dissection of the transverse carpal ligament, the related neurovascular structures and the bony landmarks of the radiocarpal, midcarpal and carpometacarpal joints of the right hand. We then used the measurements we made for percutaneous carpal tunnel release of the transverse carpal ligament using intra-operative ultrasonography for guidance and a hook knife on the left-hand side. The completeness of the release and the potential risks of injury to the flexor tendon and neurovascular bundles were examined. Using real-time intra-operative ultrasonographic monitoring to clearly delineate these targets, we were able to percutaneously release the transverse carpal ligament completely in 18 (90%) of the 20 hands and partially release it in 2 without injuring any neurovascular bundles. We then performed the procedure on 91 consecutive cases of carpal tunnel syndrome and found that the sensory disturbances disappeared in 100% patients 12 mo post-operatively; only 2 hands were graded as unsatisfactory. There were no intra- or post-operative complications. Based on the results from the cadaveric studies and our successful preliminary clinical outcomes, we conclude that this method is tolerable and that its clinical application can be encouraged.

Ultra minimally invasive sonographically guided carpal tunnel release: an external pilot study

BACKGROUND

Authors have reported better outcomes, by reducing surgical dissection for carpal tunnel syndromes requiring surgery. Recently, a new sonographically guided technique for ultra minimally invasive (Ultra-MIS) carpal tunnel release (CTR) through 1mm incision has been described.

HYPOTHESIS

We hypothesized that a clinical trial for comparing Ultra-MIS versus Mini-open Carpal Tunnel Release (Mini-OCTR) was feasible.

MATERIALS AND METHODS

To test our hypothesis, we conducted a pilot study for studying Ultra-MIS versus Mini-OCTR respectively performed through a 1mm or a 2 cm incision. We defined success if primary feasibility objectives (safety and efficacy) as well as secondary feasibility objectives (recruitment rates, compliance, completion, treatment blinding, personnel resources and sample size calculation for the clinical trial) could be matched. Score for Quick-DASH questionnaire at final follow-up was studied as the primary variable for the clinical trial. Turnover times were studied for assessing learning curve stability.

RESULTS

Forty patients were allotted. Primary and secondary feasibility objectives were matched with the following occurrences: 70.2% of eligible patients finally recruited; 4.2% of randomization refusals; 26.6 patients/month recruited; 100% patients receiving a blinded treatment; 97.5% compliance and 100% completion. A sample size of 91 patients was calculated for clinical trial validation. At final follow-up, preliminary results for Quick-Dash substantially favored Ultra-MIS over Mini-OCTR (average 14.54 versus 7.39) and complication rates were lower for Ultra-MIS (5% versus 20%). A stable learning curve was observed for both groups.

CONCLUSIONS

The clinical trial is feasible. There is currently no evidence to contraindicate nor withhold the use of Ultra-MIS for CTR.

LEVEL OF EVIDENCE

III.

Percutaneous ultrasound-guided MANOS carpal tunnel release technique

Ultrasound (US) is used with a minimally invasive cutting device to perform carpal tunnel release with a 3 mm wrist incision. US localizes tendons, arteries, and median nerve for safe introduction of the device into the wrist. The device is inserted in a blunt configuration under the flexor retinaculum, and a cutting wire is deployed that advances a 0.9-mm needle in the palm. The surgeon releases the flexor retinaculum from the inside out through the two skin punctures. Flexor retinaculum release is confirmed with US.

Value of anatomic landmarks in carpal tunnel surgery

This study investigated which anatomic landmarks were most useful for correct and safe incision placement in carpal tunnel surgery. Kirschner wires were attached to the hands to mark previously defined landmarks. The bony attachments of the transverse carpal ligament, which were identified previously, were drawn on an anteroposterior digital x-ray of the hand, with the thumb in full abduction. The relationship between anatomic landmarks and these bony attachments were examined. In all hands, either the line along the third web space or the crease between the thenar and the hypothenar regions, or both, were on the ulnar half of the transverse carpal ligament. During incision placement, we recommend selecting the most ulnar choice between the line drawn along the third web space and the crease between the thenar and hypothenar regions in order to be at safe distance from the recurrent motor branch of the median nerve.

Ultrasound-guided carpal tunnel release using the manos CTR system

PURPOSE

Ultrasound (US) has been used in the management of carpal tunnel syndrome since the 1980s. The first report of US-guided carpal tunnel release (CTR) was published in 1997, with cadaver and clinical reports confirming the safe navigation of surgical tools with US for division of the transverse carpal ligament. The MANOS CTR device was recently reported as a minimally invasive tool for CTR, and may be well suited for use with US guidance.

PATIENTS AND METHODS

The authors report three cases of US-guided CTR using the MANOS CTR device. The MANOS device was inserted in a blunt configuration into the safe zone, and the cutting surface was deployed with a thumb-activated trigger that simultaneously ejected a sharp through the palm. The transverse carpal ligament was divided safely and confirmed with US.

RESULTS

US allowed for clear identification of the median nerve, safe zones, transverse carpal ligament, and the MANOS CTR device in relation to all pertinent structures of the carpal tunnel. Complete division of the transverse carpal ligament was confirmed in all three cases. There were no median nerve, vessel, tendon injuries, or chronic regional pain syndrome in any of the three cases.

CONCLUSIONS

US-guided CTR with the MANOS CTR device appears to be a safe technique and successful in confirming complete release.

Ultra-minimally invasive sonographically guided carpal tunnel release: anatomic study of a new technique

OBJECTIVES

The purposes of this study were to measure a safe zone and a path for ultra-minimally invasive sonographically guided carpal tunnel release with a 1-mm incision in healthy volunteers and then test the procedure in cadavers.

METHODS

First, a previously reported sonographic zone was defined as the space between the median nerve and the closest ulnar vascular structure. Axially, the safest theoretical cutting point for carpal tunnel release was set by bisecting this zone. Magnetic resonance imaging was used for axially determining the limits of the sectors (origin at the cutting point) that did not enclose structures at risk (arteries and nerves) and coronally for determining whether our release path could require directions that could potentially compromise safety (origin at the pisiform's proximal pole). Second, in cadavers, we performed ultra-minimally invasive sonographically guided carpal tunnel release from an intracarpal position through a 1-mm antebrachial approach. Efficacy (deepest fibrous layer release rate), safety (absence of neurovascular or tendon injury), and damage to any anatomy superficial to transverse carpal ligament were assessed by dissection.

RESULTS

All 11 of our volunteers (22 wrists) had safe axial sectors located volar and radially of at least 80.4º (considered safe). Release path directions were theoretically safe (almost parallel to the longitudinal axis of the forearm). In 10 cadaver wrists, ultra-minimally invasive sonographically guided carpal tunnel release was effective (100% release rate) and safe without signs of intrusion into the superficial anatomy.

CONCLUSIONS

Ultra-minimally invasive sonographically guided carpal tunnel release in a safe sonographic zone may be feasible The technique preserves the superficial anatomy and diminishes the damage of a surgical approach.

Morphological study of the proximal boundary of the flexor retinaculum and of its constituent parts

The proximal boundary of the flexor retinaculum is not readily demarcated, and previous reports of three distinct regions of the flexor retinaculum were not consistent with the authors' experience. This study was undertaken to clarify the proximal boundary and the constituent parts of the flexor retinaculum. A total of 56 cadaveric wrists were used in the study. The proximal boundary of the flexor retinaculum was identified by a change in thickness and colour of the longitudinally sectioned surface of the continuous membranous sheet of the flexor retinaculum and antebrachial fascia. Steel wires were placed on the proximal and distal boundaries, and anteroposterior radiographic images were taken. MRI was carried out before dissection or serial section. The locations of the proximal and distal boundaries of the flexor retinaculum varied. The flexor retinaculum was comprised of two parts, which were distinguishable by thickness and transparency. These two parts were also identified on MR images and by light microscopy.

Clinical and ultrasonographic results of ultrasonographically guided percutaneous radiofrequency lesioning in the treatment of recalcitrant lateral epicondylitis

BACKGROUND

In patients with lateral epicondylitis recalcitrant to nonsurgical treatments, surgical intervention is considered. Despite the numerous therapies reported, the current trend of treatment places particular emphasis on minimally invasive techniques.

PURPOSE

The authors present a newly developed minimally invasive procedure, ultrasonographically guided percutaneous radiofrequency thermal lesioning (RTL), and its clinical efficacy in treating recalcitrant lateral epicondylitis.

CASE SERIES

Level of evidence, 4.

METHODS

Thirty-four patients (35 elbows), with a mean age of 52.1 years (range, 35-65 years), suffered from symptomatic lateral epicondylitis for more than 6 months and had exhausted nonoperative therapies. They were treated with ultrasonographically guided RTL. Patients were followed up at least 6 months by physical examination and 12 months by interview. The intensity of pain was recorded with a visual analog scale (VAS) score. The functional outcome was evaluated using grip strength, the upper limb Disability of Arm, Shoulder and Hand (QuickDASH) outcome measure, and the Modified Mayo Clinic Performance Index (MMCPI) for the elbow. The ultrasonographic findings regarding the extensor tendon origin were recorded, as were the complications.

RESULTS

At the time of the 6-month follow-up, the average VAS score in resting (from 4.9 to 0.9), palpation (from 7.6 to 2.5), and grip (from 8.2 to 2.9) had improved significantly compared with the preoperative condition (P < .01). The grip strength (from 20.6 to 27.0 kg) and QuickDASH score (from 54.3 to 21.0) had also improved significantly (P < .01). The MMCPI score improved from "poor" to "excellent." The ultrasonographic finding revealed that the thickness of the common extensor tendon origin did not change significantly. At the final follow-up (mean, 14.3 months; range, 12-21 months), the patients reported a 78% reduction in pain compared with the preoperative status. No major complications were noted in any patient.

CONCLUSION

Ultrasonographically guided RTL for recalcitrant lateral epicondylitis was found to be a minimally invasive treatment with satisfactory results in this pilot investigation. This innovative method can be considered as an alternative treatment of recalcitrant lateral epicondylitis before further surgical intervention.