Thumb Opposition Research Articles

Mid-Term Outcomes Following Trapeziectomy With Suture Suspensionplasty for Thumb Carpometacarpal Joint Osteoarthritis

In the treatment of symptomatic thumb carpometacarpal joint arthritis, numerous techniques have been used to maintain the trapezial space following trapeziectomy. The purpose of this study was to report the clinical and radiographic outcomes of the suture suspensionplasty technique. The hypothesis was that suture suspensionplasty would have similar clinical and radiographic outcomes compared with other techniques aimed at maintaining the trapezial space following trapeziectomy. Data were collected on 42 patients following trapeziectomy with suture suspensionplasty for symptomatic Eaton stage II-IV carpometacarpal osteoarthritis at an average follow-up of 2.1 years. Outcomes included the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire, visual analog scale for pain, radiographic analysis of subsidence, and physical examination of lateral pinch strength and thumb opposition. Radiographs demonstrated that 42% of the trapezial space was maintained at 2.1 years following trapeziectomy with suture suspensionplasty. Median postoperative QuickDASH scores were 3.4 (first quartile, 0; third quartile, 15.9), which is consistent with or better than normative values in the population. Median postoperative visual analog scale scores were 0 (first quartile, 0; third quartile, 0) with good postoperative thumb opposition and pinch strength. Patients who underwent trapeziectomy with suture suspensionplasty had similar functional and radiographic outcomes at an average of 2.1 years after surgery compared with other techniques used for treatment of symptomatic thumb carpometacarpal joint arthritis. Therapeutic IV.

Nerve compression after opponensplasty: a cadaveric study

Background: We describe the differences in thumb opposition between different opponensplasty tendon transfers and determine the immediate pressure on the median and ulnar nerves incurred by each transfer. Methods: Using fresh frozen cadavers (8 specimens), opponensplasties were performed using extensor indicis proprius (EIP), flexor digitorum superficialis (FDS) with flexor carpi ulnaris (FCU) pulley, palmaris longus (PL, Camitz procedure), and PL utilizing the thenar fascia as a pulley (PLwP). Each tendon transfer was tensioned, and the thumb flexion, abduction and pronation were measured. The pressure on the median and ulnar nerves were measured for each tendon transfer at varying tensions. Results: There were no differences seen in flexion or pronation between any of the four tendon transfers. FDS, PL and PLwP demonstrated more abduction than the EIP transfer, however differences were less than 10°. EIP and FDS transfers caused significantly more pressure on the median nerve than PL or PLwP at high tendon tensions. Both EIP and FDS tendon transfers caused significantly more pressure on the ulnar nerve than PL or PLwP, and the pressure increased as tension on the transfer increased. No pressure differences were seen between PL and PLwP. Conclusions: No significant differences were seen in thumb flexion or pronation between the four tendon transfers. Differences were seen for abduction with EIP showing the least amount of abduction. EIP and FDS caused more median nerve compression than PL transfers at high tension. Both EIP and FDS tendon transfers cause more ulnar nerve compression than PL transfers at all tensions. Level of Evidence Level: V

Outcome of Trapeziectomy and Ligament Reconstruction and Tendon Interposition for Patients Aged Less Than 56 Years: A Retrospective Study With a Minimum 5-Year Follow-Up

The purpose of this study was to determine the long-term consequences of trapeziectomy and ligament reconstruction and tendon interposition (LRTI) for trapeziometacarpal osteoarthritis in patients aged less than 56 years. A retrospective study was performed to investigate the outcome of trapeziectomy and LRTI with a follow-up period of greater than 5 years in patients aged less than 56 years at the time of surgery. Patients completed the Disabilities of Arm, Shoulder, and Hand (DASH), the Patient-Rated Wrist Evaluation (PRWE), and a 10-point visual analog score for pain (VAS). Objective assessments included thumb opposition, palmar and radial abduction angles, and grip, lateral key, and thumb tip pinch strengths. Radiographic assessments of the thumb carpometacarpal joint were performed in three planes, and the trapezial space and trapezial space to metacarpal height ratios were calculated. Between January 2005 and December 2017, 105 patients were treated. Forty-eight patients with 58 thumbs returned for review. The mean patient age at the time of surgery was 52.5 years, and 96% of the patients were women. The mean follow-up period from surgery was 11 years. The mean VAS score was 1. A significant association was found between younger age at the time of surgery and increased proximal migration of the metacarpal, between high VAS pain scores and high PRWE and DASH scores, weak grip, lateral key pinch and thumb tip pinch strength, and Kapandji score, and between the follow-up period and increasing VAS pain, PRWE, and DASH scores. Trapeziectomy and LRTI are effective procedures for patients aged less than 56 years. The benefits of surgery should be balanced against the deterioration in the outcome measures of DASH and PRWE and increasing VAS scores with increasing intervals from surgery. Therapeutic IV.

Comparative Study of Trapeziectomy with Weilby Suspensionplasty versus Implant Arthroplasty for Thumb Carpometacarpal Joint Arthritis in an Asian Population.

Background: This retrospective study compares the outcomes of trapeziectomy and Weilby suspensionplasty procedure versus implant arthroplasty using the TOUCH® prosthesis for basilar thumb arthritis in an Asian population. Methods: A total of 15 consecutive thumbs in 13 patients were included in this study. Six patients (2 male, 4 female, mean age of 62 years old) underwent trapeziectomy and Weilby suspensionplasty procedure. Seven patients (4 male, 3 female, mean age 63 years old) underwent implant CMCJ arthroplasty using the TOUCH® prosthesis. Data collected include demographics, severity of arthritis on plain radiographs of the thumb basilar joint, length of follow-up, pre- and postoperative pain levels, Kapandji thumb opposition score, grip and pinch strength and the time taken to return to work. Results: Patients in the trapeziectomy and Weilby suspensionplasty group had a mean follow-up of 4.5 months, while those in the TOUCH® implant arthroplasty group had a mean follow-up of 14 months. TOUCH® implant arthroplasty patients showed significantly higher grip strengths at 3 months post-surgery and a shorter return to work. There were no differences in pinch strength at 3 months, pinch or grip strength at 6 months or pain scores. Complications included prolonged scar hypersensitivity in two patients who underwent the Weilby suspensionplasty and a dislocated TOUCH® implant cup in one patient. Conclusions: Our study suggests that in the short term, CMCJ implant arthroplasty with the TOUCH® prosthesis produces results comparable to trapeziectomy and Weilby suspensionplasty. Level of Evidence: Level III (Therapeutic).

Exo-Glove Shell: A Hybrid Rigid-Soft Wearable Robot for Thumb Opposition with an Under-Actuated Tendon-Driven System.

Usability and functionality are important when designing hand-wearable robots; however, satisfying both indicators remains a challenging issue, even though researchers have made important progress with state-of-the-art robot components. Although hand-wearable robots require sufficient actuators and sensors considering their functionality, these components complicate the robot. Further, robot compliance should be carefully considered because it affects both indicators. For example, a robot's softness makes it compact (improving usability) but also induces inaccurate force transmission (impacting functionality). To address this issue, we present in this paper a tendon-driven, hybrid, hand-wearable robot, named Exo-Glove Shell. The proposed robot assists in three primitive motions (i.e., thumb opposition motion, which is known as one of the most important hand functions, and flexion/extension of the index/middle fingers) while employing only four actuators by using an under-actuation mechanism. The Exo-Glove Shell was designed by combining a soft robotic body with rigid tendon router modules. The use of soft garments enables the robot to be fitted well to users without customization or adjustment of the mechanisms; the metal routers facilitate accurate force transmission. User tests conducted with an individual with a spinal cord injury (SCI) found that the robot could sufficiently and reliably assist in three primitive motions through its four actuators. The research also determined that the robot can assist in various postures with sufficient stability. Based on the grasp stability index proposed in this paper, user stability-when assisted by the proposed robot-was found to be 4.75 times that of an SCI person who did not use the Exo-Glove Shell.

Effectiveness of mixed reality-based rehabilitation on hands and fingers by individual finger-movement tracking in patients with stroke

BackgroundMixed reality (MR) is helpful in hand training for patients with stroke, allowing them to fully submerge in a virtual space while interacting with real objects. The recognition of individual finger movements is required for MR rehabilitation. This study aimed to assess the effectiveness of updated MR-board 2, adding finger training for patients with stroke.MethodsTwenty-one participants with hemiplegic stroke (10 with left hemiplegia and 11 with right hemiplegia; nine female patients; 56.7 ± 14.2 years of age; and onset of stroke 32.7 ± 34.8 months) participated in this study. MR-board 2 comprised a board plate, a depth camera, plastic-shaped objects, a monitor, a palm-worn camera, and seven gamified training programs. All participants performed 20 self-training sessions involving 30-min training using MR-board 2. The outcome measurements for upper extremity function were the Fugl–Meyer assessment (FMA) upper extremity score, repeated number of finger flexion and extension (Repeat-FE), the thumb opposition test (TOT), Box and Block Test score (BBT), Wolf Motor Function Test score (WMFT), and Stroke Impact Scale (SIS). One-way repeated measures analysis of variance and the post hoc test were applied for the measurements. MR-board 2 recorded the fingers’ active range of motion (AROM) and Dunnett’s test was used for pairwise comparisons.ResultsExcept for the FMA-proximal score (p = 0.617) and TOT (p = 0.005), other FMA scores, BBT score, Repeat-FE, WMFT score, and SIS stroke recovery improved significantly (p < 0.001) during MR-board 2 training and were maintained until follow-up. All AROM values of the finger joints changed significantly during training (p < 0.001).ConclusionsMR-board 2 self-training, which includes natural interactions between humans and computers using a tangible user interface and real-time tracking of the fingers, improved upper limb function across impairment, activity, and participation. MR-board 2 could be used as a self-training tool for patients with stroke, improving their quality of life.Trial registration number: This study was registered with the Clinical Research Information Service (CRIS: KCT0004167).

Patient-Experience of Trapeziectomy for Trapeziometacarpal Osteoarthritis in Wide-Awake Local Anesthesia no Tourniquet, 2-Year Follow-up.

The purpose of this study was to assess the patient experience of trapeziectomy under WALANT for trapeziometacarpal joint (TMJ) osteoarthritis (OA) in a prospective study with 2-year follow-up. The study included 23 patients with TMJ OA undergoing trapeziectomy with WALANT. All patients were seen by a hand therapist preoperatively and at 3, 12, and 24 months postoperatively. At each visit, VAS pain scores, thumb range of motion, grip strength, and Disabilities of the Arm, Shoulder and Hand (DASH) score were assessed. The Picker Patient Experience (PPE-15) questionnaire was administered within 2 weeks of surgery. All 23 patients completed the PPE-15 questionnaire. Their mean age was 64 years. The 21 patients who remained at the 24-month follow-up all said they would choose the same anaesthesia method again. At this follow-up, VAS pain scores, thumb range of motion, key pinch grip and DASH scores had improved significantly, while thumb opposition and hand grip strength remained largely unchanged. The majority of patients felt well informed before and during the procedure, and all patients rated pain relief as good or satisfactory. Nearly 40% of patients reported receiving inadequate information about the postoperative medications. Patients have a positive attitude to trapeziectomy with WALANT, and seem to prefer WALANT over other methods of anaesthesia. Trapeziectomy with WALANT for TMJ OA is a safe procedure and appears to give a functional outcome similar to trapeziectomy under general anaesthesia. Trapeziectomy with WALANT for TMJ OA is safe, preferred by patients and has similar clinical outcome as trapeziectomy in general anesthesia. trapeziectomy, osteoarthritis, WALANT.

Surgical Reconstruction of Type IV Hypoplasia of the Thumb (Floating Thumb) in Infants: A Retrospective Analysis of Functional Outcomes and Radiographic Alignment.

BACKGROUND Congenital hypoplasia of the thumb type IV, also known as floating thumb, is a condition in which 2 small phalanges are attached to the hand with a thin skin bridge. Surgical management options for this condition vary from amputation to flap reconstruction. MATERIAL AND METHODS This retrospective study analyzed 11 infants with congenital hypoplasia of the thumb type IV who underwent surgical reconstruction using a modified vascularized polydactylous hallux flap. The study included 6 male and 5 female infants, aged 6 to 24 months. Functional evaluations and radiographic studies were conducted postoperatively. RESULTS All 11 patients underwent the complete surgical protocol. Successful vascular and nerve anastomoses were performed during the initial procedure, ensuring sufficient blood supply and neural connectivity to the transferred toes. The second operation showed promising outcomes, including improvements in thumb opposition, grasp strength, and overall function. Postoperative assessments demonstrated satisfactory radiographic alignment and no major complications during the follow-up period. CONCLUSIONS The modified vascularized polydactylous hallux flap reconstruction is a viable surgical option for managing congenital hypoplasia of the thumb type IV in infants. This technique effectively restores thumb opposition, grasp strength, and overall hand function, with satisfactory radiographic alignment and minimal complications. The study findings support the efficacy and safety of this surgical approach in addressing this rare congenital anomaly.

Outcomes of Arthrodesis of the Metacarpophalangeal Joint of the Thumb for Sequelae of Collateral Ligament Injuries: A Series of 18 Cases with 6-Year Follow-Up.

Background: Untreated or insufficiently treated collateral ligament injuries of the thumb metacarpophalangeal (MP) joint can lead to instability or even osteoarthritis. Arthrodesis is one of the treatment options available for the treatment of the sequelae of collateral ligament injuries. The objective of our study was to evaluate the radiological, clinical and functional outcomes of MP joint arthrodesis performed for sequelae of collateral ligament injuries. Methods: We conducted a retrospective, single-centre study and reviewed the files of patients who had a thumb MP joint arthrodesis following a collateral ligament injury between 2011 and 2019. We collected patient's demographic data and the results of the radiological and clinical examinations. Results: Eighteen patients were included in the study. The average age was of 53.6 years and the time between injury to arthrodesis averaged 7 years. Four patients (22%) had nonunion. In the remaining 14 patients with solid union at an average of 72 months follow-up, the visual analogue pain score at rest was 0.14, the thumb opposition was 82%, grip strength 85%, tip pinch 92% and key pinch 79% of the contralateral side. Conclusions: The clinical and functional results of patients with a successful arthrodesis are satisfactory with restoration of good grip and pinch strength. Despite a lack of thumb MP joint flexion, stability allowed force transmission and may be preferred for manual workers. Level of Evidence: Level IV (Therapeutic).

Opposition Transfer Using the Extensor Indicis Muscle and the Extensor Pollicis Brevis Tendon

PurposeThis study aimed to introduce a novel technique utilizing the extensor pollicis brevis and extensor indicis proprius tendons as power sources for thumb opposition reconstruction in cases of severe carpal tunnel syndrome (CTS) associated with thenar muscle atrophy. Further, the efficacy of this novel method and the traditional Camitz technique was compared. MethodsPatients with severe CTS and thumb opposition dysfunction who underwent surgery using the novel technique (n = 7, 9 surgeries) or the Camitz technique (n = 8, 8 surgeries) were included in the analysis. The pre- and postoperative palmar abduction angle, thumb–ring finger opposition (T–R) angle, and Kapandji score were assessed. The repeated measures ANOVA and the Mann–Whitney U test were used for statistical analysis. ResultsThe novel technique was associated with a significant postoperative improvement in palmar abduction angle, T–R angle, and Kapandji score. In particular, the T–R angle of patients who underwent surgery using this technique was superior to that of patients who underwent surgery using the Camitz technique. Therefore, the novel technique was highly effective in improving thumb pronation. ConclusionThe novel technique using the extensor pollicis brevis and extensor indicis proprius tendons is promising for thumb opposition reconstruction in severe CTS cases. Unlike the traditional Camitz technique, this approach promotes stable thumb opposition function without requiring a pulley, thereby yielding satisfactory outcomes. Nevertheless, further studies with a larger sample size should be conducted to validate these findings.

Modified Extensor Indicis Proprius Opponensplasty.

Extensor indicis proprius (EIP) opponensplasty is one of the commonly used techniques to restore thumb abduction and opposition in patients with thenar muscle dysfunction from various causes of median nerve palsy. However, its subcutaneous route around the distal ulna may not represent a straight line of pull, and part of the extensor hood sometimes has to be harvested along with the EIP tendon to gain adequate length to reach the insertion. The purpose of the study is to present the alternative method of EIP opponensplasty and report the clinical outcomes. The modified EIP opponensplasty was performed on 16 patients with severe carpal tunnel syndrome. At the final follow-up examination, all patients were able to regain their desired level of activities. The Kapandji score, abduction angle, and the disabilities of the arm, shoulder, and hand score improved in all patients. There were no complications related to harvesting the EIP tendon. Two patients developed finger stiffness, which improved after rehabilitation. This technique is safe and effective for restoring thumb function and can solve the insufficient tendon length problem of the original EIP opponensplasty.

Thumb Pronation Angle in Thumb Opposition Evaluated by the Nail Tip Angle of Thumb-Ring Finger Opposition.

This study aimed to devise the method for the evaluation of the thumb pronation angle and calculate its reference value. The study was conducted from October 2021 to March 2022, and 600 hands of 300 healthy volunteers were included in this study. The participants were divided into 6 age groups with 50 participants each. In study 1, 12 participants from group 1 were randomly selected, which included 6 male and 6 female participants. We measured the thumb pronation angle using FASTRAK system and the nail tip angle of thumb-ring finger opposition (T-R angle) and also evaluated the relation between them. In study 2, we measured the T-R angle of 600 hands of 300 healthy volunteers. The T-R angle mean (SD) and 95% confidence interval (CI) of each age group were calculated as reference values. The thumb pronation angle was correlated with the T-R angle. The T-R angle mean (SD) and 95% CI of the 6 groups were as follows: group 1, 142.5° (12.4) and 117.7 to 167.3; group 2, 139.9° (10.1) and 119.7 to 160.1; group 3, 142.3° (9.7) and 122.9 to 160.5; group 4, 140.2° (12.6) and 115.0 to 165.4; group 5, 138.3° (11.9) and 114.5 to 162.1; and group 6, 135.4° (13.0) and 109.4 to 161.4. The 95% CI tended to decrease with an increasing age. The T-R angle was a suitable evaluation method for the thumb pronation angle, and it should be evaluated by age groups.

Infiltration Technique for the Fourth FDS Opponensplasty Under WALANT

Background: Wide-awake Local Anesthesia No Tourniquet (WALANT) is a surgical technique that relies on anesthetic and hemostatic agents to provide conditions suitable for hand surgery without sedation and a tourniquet. The opponensplasty using the fourth flexor digitorum superficialis tendon transfer with the pisiform pulley is one of the most used in severe carpal tunnel syndrome patient who is unable to perform thumb opposition due to thenar muscle atrophy with the benefit of small incision, less soft tissue dissection, easy to perform, good esthetic result and has minor morbidity. Key advantages of the pisiform pulley provide balancing abduction and flexion strength of the thumb. To date, there is no report using the WALANT technique for the fourth flexor digitorum superficialis opponensplasty with pisiform pulley. Materials and Method: Between January 2019 and January 2022, 18 patients (4 males and 14 females) with severe carpal tunnel syndrome with thenar muscle atrophy underwent fourth flexor digitorum superficialis opponensplasty as day surgery under the WALANT technique. Operative data, visual analog scale (VAS) pain scores, and complications were recorded. All patients underwent the procedure without any complications. Results: The average age of the patients was 58.4 (43 to 62) year-old. The average operative time was 38.4 (17 to 47) minutes. The average VAS score during the anesthetic injection was 6.43 (4 to -8). The average VAS pain score during the operation was 2.1 (1 to 3). The mean intraoperative blood loss was 3 (2.6 to 6.2) mL. Conclusions: The WALANT technique is safe and can be used as alternative anesthesia for the fourth flexor digitorum superficialis opponensplasty with pisiform pulley. This technique overcomes the problem of judging the appropriate amount of transfer tension by observing awake patients actively. Levels of Evidence: Therapeutic study, level IV

Rare Median Nerve and Digital Nerve Tumor Resection and Distal Nerve Transfers: A Report of 2 Cases.

We present 2 cases of median nerve reconstruction using distal nerve transfers after resection of unusual benign median nerve tumors. Critical sensation was restored in case 1 by transferring the fourth common digital nerve to first web digital nerves. Thumb opposition was regained by transferring the abductor digiti minimi ulnar motor nerve branch to the recurrent median motor nerve branch. Critical sensation was restored in case 2 by transferring the long finger ulnar digital nerve to the index finger radial digital nerve. Distal nerve transfers, even with short grafts, are reliable median nerve deficit treatments, sparing the need for larger autologous nerve grafts and late tendon opponensplasties.

Carpal Tunnel Syndrome with Thenar Atrophy: Alternative Methods for Early Diagnosis and Surgical Treatment Follow-up

The objective of this study is to test the applicability of Mechanomyographic (MMG) sensors for the diagnosis of Carpal Tunnel Syndrome (CTS) as well as for the follow-up of the post-surgical evolution. After reviewing the literature, three types of MMG sensors (force sensor, accelerometer and infrared) had been selected to compare with the Electromyographic (EMG) signal widely used in clinical evaluation. Three tests (two static and one dynamic) were then defined to evaluate thenar atrophy and thumb opposition strength as well as grip strength. This paper makes a description of the tests that had been carried out, starting from the procedure implemented for the application of the sensors and ending at the method used for sensor readout. Preliminary results obtained from a sample of twelve volunteers, which includes one with CTS surgery performed less than six months ago, are promising namely those from the measurement of thumb opposition strength.

Effect of intraoperative hand-grip position on surgical outcome of thumb carpometacarpal arthrodesis

BackgroundA variety of surgical techniques had been developed over the past few decades for treating thumb carpometacarpal joint (CMCJ) osteoarthritis (OA). However, there are currently no accepted consensus on the ideal treatment for thumb CMCJ OA. Arthrodesis was one of the widely popular treatment methods; however, studies have showed that non-union rates were as high as 50%, with higher complications such as osteoarthritis of neighbouring joints and higher revision surgeries required as compared to other surgical methods. Patients with arthrodesis were also reported to have decreased thumb range of motion and loss of opponens function. Currently, there are numerous intraoperative positioning techniques for arthrodesis which could be confusing for young surgeons. With recent developments of fixation plates and better understanding of the wrist anatomy, this retrospective review aimed to evaluate the efficacy of our intraoperative hand-grip positioning method for arthrodesis of thumb CMCJ OA. What are the postoperative functional outcomes of (1) T-hook plates and (2) our intraoperative hand-grip positioning method for Eaton III thumb CMCJ OA arthrodesis by evaluating pain visual analogue scale (VAS) score, Disabilities of the Arm, Shoulder and Hand questionnaires (DASH), Mayo Wrist scores, capability of thumb opposition (Kapandji score), and comparing pre- and postoperative grip and pinch strength?MethodsTwenty patients with CMCJ OA underwent arthrodesis using our intraoperative hand-grip positioning method and T-hook plates and screws (Acumed, USA). Patients were evaluated preoperatively and at 1, 3, 6 and 12 months postoperatively. Radiologic assessment including fusion evaluation, evaluation of radial and palmar abduction angles was done on hand X-rays.ResultsTwenty patients with a minimum follow-up duration of 12 months were included in this study. 100% fusion rate was achieved with only 1 case of complication involving radial sensory nerve neuropathy which was resolved after removal of implant and neurolysis. Significant improvement in pain and Mayo Wrist scores were noted 3 months postoperatively, whilst DASH score exhibited significant improvements after 6 months of follow-up (p < 0.05). Even though there were no significant differences observed between preoperative and postoperative grip strength, pinch strength and Kapandji scores, positive recovery trends were noted for all parameters with these functions surpassing preoperative levels after 12 months of follow-up. Significant improvements on hand X-rays were also noted for both postoperative radial and palmar abduction angles.ConclusionsThere is currently no consensus on the ideal treatment method for thumb CMCJ OA. In this study, we would like to propose a simple intraoperative hand-grip positioning method with T-hook plates for arthrodesis. As seen from our results, our technique was able to provide satisfactory and replicable postoperative results and thus we would like to propose our hand-grip positioning method with T-hook plates fixation for subsequent treatment of patients with Eaton stage III thumb CMCJ OA.

Thumb pronation efficacy of Camitz tendon transfer with insertion on the ulnar capsule of the metacarpophalangeal joint: a cadaver study.

Several studies have indicated that Camitz transfer for severe carpal tunnel does not adequately restore thumb opposition. The aim of this study was to determine whether modification of the distal insertion of the transferred palmaris longus tendon could provide more effective opposition. We used 12 fresh-frozen upper extremity specimens. For spatial analysis, we used a three-dimensional motion-tracking device. At 0 N and 5 N of traction force, the pronation angle was significantly larger for the modified procedure than for the conventional procedure. There was no significant difference in the palmar abduction angle between the two groups. The modified palmaris longus tendon insertion on the ulnar side of the thumb metacarpophalangeal joint provides more effective thumb pronation than conventional Camitz opponensplasty in a cadaver model. .

Dexterous all-soft hand (DASH) with active palm: multi-functional soft hand beyond grasping

Safety and adaptability are key features of anthropomorphic robotic hands and tend to receive significant attention, however, the motion of the palm, which is also an essential element of a dexterous hand, is often ignored. Not only does a rigid palm lack compliance, but its limited manipulative capacity restricts the soft anthropomorphic hand’s range of applications. Thus, in this study, we present the dexterous all-soft hand (DASH), featuring an active palm based on pneumatic actuation. The DASH is comprised of five fingers and an active palm with 11 degrees of freedom, which enable it to achieve a range of metacarpal motions as well as thumb opposition. A step-by-step casting method was used to fabricate the hand and a set of tests were performed to characterize the bending angle and the blocked force between fingers and palm. The ability of this novel hand to achieve the highest possible scores in the Kapandji test, the injection operation, scissors manipulation and unscrewing the cap was subsequently demonstrated. The DASH is the same size as an average adult female hand, and offers the additional benefits of light weight (165 g), low cost and ease of fabrication. Moreover, its manipulation ability further broadens the range of potential applications for this type of robotic hand.

Transfer of the palmaris brevis motor branch to the thenar motor branch: A cadaveric preliminary study

ObjectiveHigh median nerve injuries can lead to poor distal recovery, especially poor functioning of median innervated thenar muscles involved in thumb opposition and palmar abduction. The palmaris brevis (PB) is a small subcutaneous muscle innervated by ulnar nerve. Innervation of the PB is in most of cases provided by the ulnar digital nerve to the little finger. The purpose of this study is to assess the feasibility of transferring the PB motor branch (PBMB) to the median nerve thenar motor branch (TMB), in order to allow for early restoration of thumb palmar abduction and opposition, through a preliminary cadaveric study. MethodsTwenty-five cadaver upper limbs were dissected under magnification. The length of the PBMB and TMB, and their origin were recorded. Nerve transfer from PBMB to TMB was conducted, and evaluated on 2 parameters: surgical feasibility, and distance from the coaptation site to the recipient nerve muscle entry point. The PBMB and TMB were harvested, fixated in formalin, then embedded in paraffin. They were sectioned transversely, and stained with a combination of hematoxylin–eosin and Luxol fast blue. Myelinated axons were counted in each specimen and the donor-to-recipient axon ratio was recorded. ResultsThe PBMB was constant and originated from the ulnar digital nerve of the little finger in all cases. The transfer from PBMB to TMB was feasible in all cases. Mean myelinated axon counts of PBMB and TMB were 253±142 and 356±198, respectively (p=0.06). The donor-to-recipient axon ratio was 1:1.41. The mean distance from coaptation of the PBMB to the recipient thenar muscles was 23.1±3.0mm. ConclusionsBased on our results, PBMB to TMB transfer is feasible. The PBMB has the advantage over other distal nerve transfer donors to be constant and superficial, allowing for an easier harvest. Moreover, this procedure does not sacrifice any intrinsic function of the hand, and the proximity of the PBMB with the carpal tunnel allows for a single incision procedure. Therefore, early restoration of the median innervated thenar muscles may be feasible by the PBMB to TMB transfer in cases of high median nerve lesions. Level of evidenceIV.

Wide-awake local anesthesia no tourniquet and dexamethasone (WALANT-D) for modified Camitz opponens plasty in severe carpal tunnel syndrome-a retrospective study of 30 cases

BackgroundTo analyze the outcome of modified Camitz opponens plasty using the wide-awake local anesthesia no tourniquet with dexamethasone (WALANT-D) technique in severe carpal tunnel syndrome (CTS). MethodsA retrospective review was performed in 30 hands of 27 patients who underwent Camitz opponens plasty for severe CTS between 2019 and 2021. All patients had 8 mg of dexamethasone mixed with WALANT. Preoperative active palmar abduction, grip strength, side, and pulp pinch strength, Kapandji score, and electrophysiological assessment of compound muscle action potential (CMAP) for abductor pollicis brevis (APB) were compared with the postoperative values. The palmaris longus had dual insertion into the abductor pollicis brevis and extensor expansion. The time interval of post-operative pain-free was noted. The Disabilities of the Arm, Shoulder, and Hand (DASH) and Carpal Tunnel Syndrome instrument (CTSI) also assessed the functional outcome. ResultsThe mean age of patients was 35 years (range 32–58 years). There were five male and 22 female patients. Of the female patients, three females had severe bilateral CTS. Twenty right and ten left hands were affected. The mean follow-up of our study was 12.5 months (range 10–14 months). The patients were pain-free for an average of 19.5 h postoperatively. There was a significant improvement in the thumb palmar abduction, grip strength, side, and pulp pinch strength, DASH score, CTSI, and APB-CMAP (p < 0.05) at the final follow-up. ConclusionsModified Camitz opponens plasty with a dual insertion into APB and extensor expansion effectively improves thumb opposition and daily activities. The tendon tensioning, checking the pulley impingement, appreciation of active movements, and a comfortable patient operative experience are advantages of the WALANT. Adding dexamethasone as an adjuvant to WALANT prolongs the analgesia and duration of the nerve block. Level of evidenceIV, Retrospective case study.