Metacarpophalangeal Joint Hyperextension Research Articles

Paediatric trigger thumbs: patient-reported outcome measures over a minimum of ten years' follow-up.

The paediatric trigger thumb is a distinct clinical entity with unique anatomical abnormalities. The aim of this study was to present the long-term outcomes of A1 pulley release in idiopathic paediatric trigger thumbs based on established patient-reported outcome measures. This study was a cross-sectional, questionnaire-based study conducted at a tertiary care orthopaedic centre. All cases of idiopathic paediatric trigger thumbs which underwent A1 pulley release between 2004 and 2011 and had a minimum follow-up period of ten years were included in the study. The abbreviated version of the Disabilities of Arm, Shoulder and Hand questionnaire (QuickDASH) was administered as an online survey, and ipsi- and contralateral thumb motion was assessed. A total of 67 patients completed the survey, of whom 63 (94%) had full interphalangeal joint extension or hyperextension. Severe metacarpophalangeal joint hyperextension (> 40°) was documented in 15 cases (22%). The median QuickDASH score was 0 (0 to 61), indicating excellent function at a median follow-up of 15 years (10 to 19). Overall satisfaction was high, with 56 patients (84%) reporting the maximal satisfaction score of 5. Among 37 patients who underwent surgery at age ≤ two years, 34 (92%) reported the largest satisfaction, whereas this was the case for 22 of 30 patients (73%) with surgery at aged > two years (p = 0.053). Notta's nodule resolved in 49 patients (73%) at final follow-up. No residual triggering or revision surgery was observed. Surgical release of A1 pulley in paediatric trigger thumb is an acceptable procedure with excellent functional long-term outcomes. There was a trend towards higher satisfaction with earlier surgery among the patients.

Correction of Complex Clawing after Cerebral Infarct via All-Dorsal ECRB Tendon Transfer using Four-Tailed Plantaris Autograft

Clawing refers to pathologic hand posture of metacarpophalangeal joint hyperextension and proximal interphalangeal joint flexion, with variable presentation in appearance and functional deficits depending on underlying etiology, chronicity, and attempts at treatment. Characteristic deficits include the clawed appearance, loss of synchronous finger flexion, weakened grip and pinch strength, and impaired dexterity from loss of fine motor control. Surgical treatment varies for simple versus complex clawing, with additional nuances for associated pathology such as extensor mechanism attenuation, flexor myotendinous tightness, and intrinsic joint contracture. Conditions such as stroke or combined ulnar and median neuropathy require special consideration, as median-innervated myotendinous donors are not suitable. The present technique describes all dorsal extensor carpi radialis brevis tendon transfer via four-tailed plantaris autograft to the lateral bands for treatment of complex clawing after cerebral infarct.

Inter- and Intra-observer Agreement of Visual Estimation, Goniometric and Radiographic Measurement of Passive Thumb Metacarpophalangeal Joint Hyperextension.

Background: Reliable methods for measuring range of motion is important for hand therapists. Currently, there is no gold standard for the measurement of thumb metacarpophalangeal joint (MCPJ) hyperextension. We hypothesised that visual and goniometric measurements of thumb MCPJ hyperextension vary greater than 10° from radiographic measurements, and between observers. Methods: Twenty-six fresh-frozen hands were measured by a senior orthopaedic resident and fellowship trained hand surgeon. Passive thumb MCPJ hyperextension was measured by visual estimation, goniometry and axis measurement on a lateral thumb radiograph. Raters were blinded to each other's and their own prior measurements. Descriptive statistics were recorded for measurement type and inter-observer agreement using a two-way intra-class correlation coefficient (ICC). Intra-observer agreement was calculated using concordance correlation coefficient (CCC). Bland-Altman plots identified trends, systemic differences or potential outliers. Results: Mean measurements for both raters were similar for visual estimation and radiographic measurements. Mean goniometric measurements were twice as high for Rater B, and closer to radiographic measurements. For both raters, mean radiographic measurements were 10° greater than the other two methods. For inter-rater agreement, measurements were within 10° most frequently with radiographic measurement, then visual estimates, and least by goniometer measurements. Rater B had better agreement comparing visual and goniometric to radiographic measurements. Conclusions: Radiographic measurement has the best inter-observer agreement and precision for evaluating passive thumb MCPJ hyperextension, especially considering adjunct corrective procedures when performing a soft-tissue basal joint arthroplasty. Rater experience improves precision, but there is still poor agreement between visual estimates and goniometer measurements compared to radiographic measurements, as the former two underestimate hyperextension by 10°. Development of a standard method of clinical measurement is needed to improve reliability.

Dual mobility prosthesis for trapeziometacarpal osteoarthritis: results from a prospective study of 55 prostheses.

This prospective study evaluated outcomes after trapeziometacarpal joint replacement with a dual mobility prosthesis (Touch®) in 55 thumbs (52 patients) with a mean follow-up of 25 months (range 12-36). Pre- and postoperative assessments included pain, range of motion, the Kapandji index, pinch- and grip strength, as well as functional scores and radiological parameters. Mean preoperative metacarpophalangeal joint hyperextension of 19° (range 15°-28°) showed a significant correction after 1 year with a mean value of 2° (range 0°-5°). Mean Quick Disabilities of the Hand, Shoulder and Arm score was 14 (range 6-28), and Michigan Hand Questionnaire 82 (range 67-92). No revisions due to infection, loosening, dislocation or material failure occurred during follow-up. The dual mobility trapeziometacarpal joint prosthesis was a reliable treatment option to decrease pain, improve motion, strength and pre-existing metacarpophalangeal joint hyperextension at short-term follow-up.Level of evidence: IV.

The Effect of Thumb Metacarpophalangeal Hyperextension on Thumb Axial Load and Lateral Pinch Force in a Cadaver Model of Thumb Trapeziectomy and Flexor Carpi Radialis Suspensionplasty

The purpose of our study was to investigate, in a cadaver model, the effect of increasing thumb metacarpophalangeal (MCP) joint hyperextension on thumb axial load and key pinch forceafter thumb trapeziectomy and flexor carpi radialis suspensionplasty. We developed a cadaveric model to test whether thumb MCP joint hyperextension after trapeziectomy would have a negative effect on key pinch force and increase loads across a reconstructed thumb carpometacarpal (CMC)joint. We created a cadaveric biomechanical model that varied thumb MCP joint hyperextension while measuring thumb CMC axial and key pinch force under standardized loads. Direct observations were made of how key pinch and axial thumb CMC force change with increasing thumb MCP joint hyperextension. We measured the thumb key pinch force and axial thumb CMC joint load with the thumb MCP joint in 0°, 10°, 20°, 30°, 40°, 50°, and 60° of hyperextension. There was a 0.88 N (2.4%) increase in axial force across the thumb CMC per every 10° of increasing thumb MCP joint hyperextension. We found a 0.53 N (4.4%) reduction in key pinch force for every 10° of increasing thumb MCP joint hyperextension. Therefore, at 60° of thumb MCP joint hyperextension, the axial force across the thumb CMC increased by 5.3 N (14.6%) and the key pinch force was weakened by 3.2 N (26.6%). With progressive thumb MCP joint hyperextension after thumb CMC arthroplasty, we found a decrease in key pinch force and an increase in axial thumb CMC joint force. The decrease in key pinch force was larger than the relatively small increase in thumb CMC force. This study helps elucidate the biomechanics of the thumb CMC joint after resection arthroplasty with thumb MCP joint hyperextension and helps understand the interplay between these 2 conditions.

Outcomes after Anterior Interosseous Nerve to Ulnar Motor Nerve Transfer.

Background Ulnar nerve lesions proximal to the elbow can result in loss of intrinsic muscle function of the hand. The anterior interosseous nerve (AIN) to deep motor branch of the ulnar nerve (DBUN) transfer has been demonstrated to provide intrinsic muscle reinnervation, thereby preventing clawing and improving pinch and grip strength. The purpose of this study was to evaluate the efficacy of the AIN to DBUN transfer in restoring intrinsic muscle function for patients with traumatic ulnar nerve lesions. Methods We performed a prospective, multi-institutional study of outcomes following AIN to DBUN transfer for high ulnar nerve injuries. Twelve patients were identified, nine of which were enrolled in the study. The mean time from injury to surgery was 15 weeks. Results At final follow-up (mean postoperative follow-up 18 months + 15.5), clawing was observed in all nine patients with metacarpophalangeal joint hyperextension of the ring finger averaging 8.9 degrees (+ 10.8) and small finger averaging 14.6 degrees (+ 12.5). Grip strength of the affected hand was 27% of the unaffected extremity. Pinch strength of the affected hand was 29% of the unaffected extremity. None of our patients experienced claw prevention after either end-to-end ( n = 4) or end-to-side ( n = 5) AIN to DBUN transfer. Conclusion We conclude that, in traumatic high ulnar nerve injuries, the AIN to DBUN transfer does not provide adequate intrinsic muscle reinnervation to prevent clawing and normalize grip and pinch strength.

Reconstructive Surgery of Ulnar Claw Hand in Leprosy Patients by Lasso Procedure

Leprosy, Hansen's disease caused by mycobacterium leprae, is widely known. Though there has been a substantial achievement in recent years given eliminating the disease, the deformity caused by the disease needs to be managed by reconstructive surgery. The ulnar nerve being superficial, is the most common nerve affected. When affected, the muscles innervated by the nerve begin to weaken, leading to a disparity between the strong extrinsic muscles and the weakened intrinsic muscles and is characterized clinically by metacarpophalangeal joint hyperextension and flexion of the proximal and distal interphalangeal joint. Doing reconstructive surgery on these patients will help them carry out day-to-day activities and reduce social awkwardness. Corrective surgeries like modified Stiles-Bunnell transfer, extensor carpi radialis graft, Zancolli lasso procedure, and palmaris longus tail graft are known to us. Out of all, the Zancolli lasso procedure was chosen for operating on all our cases because all other surgeries need high precision with proper training and proper post-operative physiotherapy. The study aims to evaluate the functional outcome of patients with leprotic ulnar claw hand operated with the Zancolli lasso procedure. Objectives assessed were deformity correction, grip strength, and range of motion. During the last two years, ten patients with ulnar claw hands came to Sree Balaji Medical College and Hospital, Chennai. They were operated on with the Zancolli Lasso procedure with adequate results. The zancolli procedure is easy to do and can be done in small centers, which restores finger flexion and doesn’t harm other superficialis tendons, thus preventing swan neck deformity of the fingers.

Management of Thumb Metacarpophalangeal Hyperextension in the Setting of Thumb Basal Joint Arthritis.

Thumb metacarpophalangeal (MCP) joint hyperextension is a well-established sequela of advanced carpometacarpal (CMC) joint arthritis. This deformity results in poor patient function because the ability to perform key pinch is negatively affected. For this reason, surgeons must consider the presence of an MCP deformity when addressing CMC arthritis. A variety of nonsurgical and surgical interventions have emerged. Surgical treatments can be grouped into four main categories: (1) volar plate advancement/capsulodesis, (2) tendon transfer and tenodesis, (3) sesamoidesis, and (4) arthrodesis. Surgical intervention is based on both the degree of deformity present and the surgeon preference. This review aims to clarify indications for various treatments of MCP joint hyperextension, outline commonly performed procedures, and report the published outcomes and potential complications of these interventions.

Prognostic factors and clinical features in metacarpophalangeal joint hyperextension after ligament reconstruction with trapeziectomy: A retrospective cohort study

BackgroundManagement of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes. MethodsWe investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°–20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR). ResultsOverall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821). ConclusionsPostoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.

Paediatric Trigger-Locked Thumb.

Paediatric trigger-locked thumb (PT-LT) is a common paediatric thumb condition. It is an acquired flexion deformity of the interphalangeal joint because of a size mismatch between an enlarged flexor pollicis longus tendon and a stenotic oblique pulley. It may present clinically as paediatric locked thumb which is more common or infrequently as paediatric trigger thumb. Paediatric locked thumb is classified into two types based on the presence of metacarpophalangeal joint (MCPJ) hyperextension. Type I does not have MCPJ hyperextension, whereas type II is associated with MCPJ hyperextension. The treatment of PT-LT is determined by the patient's age, time of onset, presentation, and type. Treatment modalities are observation, splinting, therapy, or surgery. Surgery involves dividing the A1 pulley and, most importantly, part of the oblique pulley. Level of Evidence: V (Therapeutic).

Extensor Pollicis Brevis Transosseous Tenodesis Technique for Treatment of Acquired Metacarpophalangeal Hyperextension Deformity of the Thumb: A Preliminary Report.

Hyperextension deformity of the metacarpophalangeal joint of the thumb causes pain and loss of function. Although many treatments have been proposed, none of them are universally accepted as ideal. The authors report a study of 12 symptomatic hyperextension deformities of the thumb metacarpophalangeal joint in 10 patients who underwent surgical correction. The purpose of this study was to describe a new technique of tenodesis of the thumb metacarpophalangeal joint using the extensor pollicis brevis tendon. The technique consists of extensor pollicis brevis tenotomy at the wrist and tendon transfer through two bone tunnels to the palmar aspect of the metacarpophalangeal joint before metacarpal fixation with a flexor tenodesis effect. Correction of hyperextension and range of motion were assessed. Functional changes were evaluated by Quick Disabilities of the Arm, Shoulder, and Hand score, pain visual analogue scale, Kapandji opposition scheme, and pinch strength. The Wilcoxon test was used for statistical analysis. Mean preoperative and postoperative metacarpophalangeal joint hyperextension deformities were +50.83 ± 5.57 degrees and -17.91 ± 7.82 degrees, respectively. Thumb opposition improved by one point on Kapandji's scheme. Mean perceived pain decreased from 7.66 to 1.16. On average, the Quick Disabilities of the Arm, Shoulder, and Hand score was reduced by 34.4 points and pinch strength increased by 50.42 percent. The authors found that extensor pollicis brevis transosseous tenodesis is a safe and minimally invasive method for successfully correcting the functionality and cosmetic appearance of metacarpophalangeal joint hyperextension deformities in posttraumatic and trapeziometacarpal osteoarthritis cases. The patients retained functional active flexion, even in deformities greater than 40 degrees. Therapeutic, IV.

Risk factors for residual pain after ligament reconstruction and tendon interposition on osteoarthritis of the first carpometacarpal joint.

Ligament reconstruction and tendon interposition (LRTI) is currently the most performed procedure for osteoarthritis (OA) of the thumb carpometacarpal (CMC) joint. In general, satisfactory outcomes are expected, although some patients complain of residual pain after LRTI. The objective of this study is to determine the factors associated with residual pain. All patients with OA of the thumb CMC joint who underwent LRTI at our hospital between October 2013 and October 2018 and were regularly observed for at least 1year were included. The following variables were extracted and included in the univariate analysis: sex, age, dominant hand, pain visual analog scale (VAS) score, Eaton classification, grip strength, pulp pinch strength, and metacarpophalangeal joint hyperextension angle were recorded as variables. Mann-Whitney U test or Fisher exact test was used for univariate analysis of the above factors, and then multivariate logistic regression analysis was performed to find out the factors associated with residual pain. The study included 60 thumbs of 53 patients. Eleven thumbs had postoperative residual pain. The surgery on the dominant hand was significantly associated with the presence of postoperative residual pain, especially in males. Dominant hand was associated with residual pain after LRTI for OA of the thumb CMC joint, although residual pain was minimal. Our findings will help in preoperative and postoperative counseling of patients. In the future, our results may also help select surgical procedures according to the patient's characteristics.

Does trapeziectomy with ligament reconstruction and tendon interposition arthroplasty correct the metacarpophalangeal joint hyperextension associated with trapeziometacarpal osteoarthritis?

Trapeziometacarpal osteoarthritis sometimes results in hyperextension of the thumb metacarpophalangeal (MCP) joint, which could negatively impact outcomes following trapeziectomy with ligament reconstruction and tendon interposition (LRTI) arthroplasty. Although algorithms on performing trapeziectomy with LRTI for the management of this deformity are available, they lack clear evidence. Here, we investigate the function of the thumb MCP joint after trapeziectomy with LTRI and whether this procedure alone corrects preoperative MCP hyperextension, and also analyze clinical factors correlated with MCP hyperextension post-surgery. Twenty-eight patients who underwent trapeziectomy with LRTI and followed up for at ≥ 1year (mean, 27.2months) were retrospectively analyzed. No patient had concomitant surgery to the thumb MCP joint at the time of trapeziectomy with LRTI. Patients were divided into the < 30° (n = 19) and > 30° (n = 9) hyperextension groups as per their preoperative passive range of motion (ROM) of the MCP joint. Changes in ROM of the MCP joint post-surgery, clinical factors correlated with postoperative MCP hyperextension, and correlations between clinical outcomes and postoperative MCP extension were analyzed. In the < 30° MCP hyperextension group, active and passive extensions of the MCP joint did not significantly change after surgery, and no worsening of postoperative MCP hyperextension was observed. In the > 30° hyperextension group, passive extension of the MCP joint significantly decreased (mean, 49.6°-29.8°). Preoperative MCP hyperextension improved in seven patients, was unchanged in 1, and worsened in 1. Postoperative passive MCP extension was negatively correlated with active/passive radial abduction, MCP flexion, trapezial space height, subjective outcomes, and hand strength post-surgery. Trapeziectomy with LRTI alone could prevent postoperative thumb MCP hyperextension deformity for patients with thumb MCP extension < 30° and improve preoperative thumb MCP hyperextension. However, for patients with loss of radial abduction and MCP flexion due to the contracture, indirect correction of the MCP hyperextension was improbable.

Metacarpophalangeal joint hyperextension in rhizartrosis: is surgical correction necessary?

Background and aim: Rhizarthrosis represents 10% of all arthritic manifestations and its prevalence increases with age and in women. The hyperextension of the metacarpophalangeal joint (MCPj) is consequent to a progressive dorsoradial subluxation of the trapeziometacarpal joint (TMj) in advanced osteoarthritis. The aim of this retrospective study is to evaluate the clinical and functional results of 32 patients affected by advanced rhizarthrosis who underwent to modified Burton-Pellegrini’s trapeziectomy in absence of surgical correction of MCPj hyperextension in order to understand when this last step is really necessary.Methods: Patients were assessed trough DASH and PRWHE questionnaires; the functionality of the hand was assessed by carrying out specific test (grip strength, key-pinch, kapandji test, reduction of wrist flexion strength) and the degree of MCP joint hyperextension was recorded. Results: Clinical evaluation and individual satisfactory were positive in most cases (mean DASH 19 and mean PRWHE 21.8, with a reduction of 77% of VAS pain score). Kapandji test was excellent in 26 patients and grip strength and key pinch were stackable in operated and non-operated hands. Twenty-five out 32 patients presented a MCP joint hyperextension between 0° and 5°, 5 of 10° and other 2 of 15°.Conclusion:Modified Burton-Pellegrini’s trapeziectomy is a valid option to treat patient with TMj osteoarthritis. The absence of surgical correction of the MCPj does not affect clinical and functional results in deformities <15°. (www.actabiomedica.it)

Effectiveness of Distal Nerve Transfers for Claw Correction With Proximal Ulnar Nerve Lesions

To evaluate claw deformity correction following anterior interosseous nerve (AIN) end-to-end transfer to the deep motor branch of the ulnar nerve (DMBUN) in high ulnar nerve injuries. Eleven patients were retrospectively evaluated for metacarpophalangeal joint hyperextension and proximal interphalangeal joint extension lag in the fourth and fifth digits following ulnar nerve injury adjacent or proximal to the elbow, who underwent AIN end-to-end transfer to the DMBUN. Patients underwent surgery an average of 5 months following injury (range, 2-9 months) and were followed for an average of 19 months after surgery (range, 12-30 months). At the last follow-up, clawing was observed in all patients, with proximal interphalangeal joint extension lag averaging 46.8° (SD, ±20°) in the fourth digit and 57.7° (SD, ±12°) in the little finger. None of our patients experienced claw correction after AIN end-to-end transfer to the DMBUN. Therapeutic IV.

Pediatric Trigger Thumb with Metacarpophalangeal Joint Hyperextension or Instability.

BackgroundThe aim of this study was to provide the first on report on the mechanism and the different treatment measures of metacarpophalangeal joint hyperextension (MCPH) or metacarpophalangeal joint instability (MCPI) in cases of pediatric trigger thumb. Some pediatric trigger thumb patients have disease combined with excessive extension of metacarpophalangeal (MCP) joint or instability of MCP joint.Material/MethodsA total of 1083 children with trigger thumb surgery were divided into 2 groups (the MCPH group and the MCPI group) by the extension degree of the MCP joint. After tendon sheath released, the MCPH group was treated by a cast and the MCPI group was treated by a cast and a brace. We compared the differences in baseline data and the further functional activities of interphalangeal (IP) and MCP joint between the 2 groups.ResultsAmong the 1083 cases, 154 cases (185 thumbs) were trigger thumb with MCPH or MCPI, of which 167 thumbs were placed in the MCPH group and 18 thumbs were placed in the MCPI group. The average age of the MCPH group was 2.8 years, with an average duration of disease of 13 months. The average age of the MCPI group was 6.6 years, with an average duration of disease of 33 months. MCPH still existed after cast removal. In the MCPI group, 12 out of 18 thumbs recovered; 6 thumbs relapsed at 2–4 months after brace removal.ConclusionsTrigger thumb with MCPH and MCPI in children is significantly associated with multi-joint laxity. While there was still MCPH after cast treatment, there was no need for further treatment during the short-term follow-up. Cast and brace treatment after surgery was a simple, easy method for treatment of MCPI and had a good effect.

Suture Suspension Arthroplasty With Trapeziectomy for Thumb Carpometacarpal Arthritis Using a Wide-awake Approach.

Despite the introduction of various techniques for ligament reconstruction in the treatment of thumb carpometacarpal (CMC) arthritis, complications, including proximal migration, dorsal subluxation of the first metacarpal base, hyperextension of the thumb metacarpophalangeal joint, and impingement between the first and second metacarpal bases, have been reported. Even suture button suspensionplasty with Arthrex Mini TightRope may be unable to correct the adduction contracture deformity and does not effectively tether the trapeziometacarpal toward the base of the index metacarpal, thus potentially leaving patients with persistent decreased first web space angle, proximal migration, and collapse deformity. Hence, suture suspension arthroplasty with abductor pollicis longus (APL)-flexor carpi radialis (FCR) tendon suture after trapeziectomy, a simpler technique, was applied. This simple surgical reconstruction abducts the first metacarpal bone. Abduction of the CMC joint improves metacarpophalangeal joint hyperextension. However, strong tension of the APL-FCR causes abduction contracture of the first CMC joint and difficulty of pinch motion of the thumb to the other fingers. Therefore, we have modified the arthroplasty with a wide-awake approach. The procedure is performed with the patient fully awake under local anesthesia, without a tourniquet to allow the patient to actively move and pinch the thumb, which allows the surgeon to confirm the tension of the APL-FCR suture. A fiber wire is connected to the APL-FCR with proper tension. The patient and surgeon can ensure pinch motion and thumb opposition with satisfaction during surgery.

Metacarpophalangeal Arthrodesis with Resection-suspension Arthroplasty in First Carpometacarpal Osteoarthritis

AbstractFirst carpometacarpal joint osteoarthritis (CMC-1) may develop first metacarpophalangeal joint hyperextension (MCP-1). We enrolled patients with CMC-1 osteoarthritis and MCP-1 hyperextension ≥40 degrees treated with resection-suspension arthroplasty and MCP-1 intramedullary arthrodesis with XMCP™ system. Minimum follow-up was five years. We evaluated: thumbinterphalangeal (IP) range ofmotion, key pinch, hand grip, Kapandji, VAS and Quick DASH. Wilcoxon test was uses for statistical analysis.Nineteen patients were reviewed. We found improvement in key pinch, hand grip, VAS and Quick DASH; statistical difference (p &lt; 0.05) was observed in all of them except key pinch. IF thumb range of motion and Kapandji decreased.TMC arthrodesis with XMCP™ system associated with resection-suspension arthroplasty, as a treatment for CMC-1 osteoarthritis and MCP-1 hyperextension ≥40 degrees, achieves good functional results in the medium term.

Consideration for Infants with Thumb Metacarpophalangeal Joint Hyperextension Laxity in the Use of Scissors

Consideration for Infants with Thumb Metacarpophalangeal Joint Hyperextension Laxity in the Use of Scissors

Development of a Biomimetic Extensor Mechanism for Restoring Normal Kinematics of Finger Movements Post-Stroke.

Cable-driven devices for hands allow compact and lightweight design that could provide various functional movements. However, for many patients post-stroke, cable-driven devices produce nonphysiologic movements, such as metacarpophalangeal joint hyperextension, due to their abnormal passive joint impedance. In this study, we developed a novel bio-inspired device mimicking the anatomy of the extensor mechanism of the human finger, which can be tuned for individuals to provide 'subject-specific' assistance to achieve physiological movement patterns. We first evaluated the proposed design via mathematical modeling and computer simulation. Its performance was then tested experimentally with twenty-four subjects, including six healthy and eighteen chronic stroke survivors. We determined the loading condition of the device from the experimental identification of passive joint impedance of each subject before device use. Our results showed that the proposed design could achieve improved spatiotemporal coordination of finger movements compared to conventional cable-driven design by providing 'subject-specific' assistance based on identified passive stiffness values of each subject. We also identified a significant (negative) correlation between the metacarpophalangeal joint stiffness and the intrinsic exotendon loading level across subjects. The proposed system can restore normal movement patterns for patients with different types of impairments, which were previously found important in improving rehabilitative outcomes.