[Base-of-thumb osteoarthritis: aspects to be considered with the indication of trapeziectomy and CMC I prosthesis]. / Die Daumensattelgelenksarthrose ­ Aspekte zur Indikationsstellung von Resektionsarthroplastik und Daumensattelgelenksprothese.

Base-of-thumb osteoarthritis is the most frequent osteoarthritis of the hand requiring surgical treatment, although conservative treatment options should be exhausted before surgery. If the wear process progresses with continuing pain-related loss of thumb function, thus leading to a loss of function of the whole hand, surgical treatment is indicated. In 1947, Gervis published results after trapeziectomy and heralded the development of a multitude of different surgical procedures. The long time needed for rehabilitation is a major problem of trapeziectomy with or without tendon interposition and/or suspension. After the implementation of the first CMC I prosthesis by De la Caffiniere 50 years ago, a rapid development took place, leading to the current modular bipolar implants. Especially in the German-speaking world, there is still some scepticism regarding these prostheses, which is why this review aims to illuminate both surgical procedures with a special focus placed on the aspects of indication.

[Cup Placement in Thumb Carpometacarpal Joint Prostheses: The Role of the Guidewire]. / Pfannenplatzierung bei Daumensattelgelenksprothesen: Die Rolle des Führungsdrahts.

BACKGROUND: The increasing use of thumb carpometacarpal joint prostheses for advanced CMC 1 (carpometacarpal) joint arthritis reflects the success of the latest prosthesis generations, which has been achieved through their improved functional outcomes and lower complication rates. Precise alignment of the prosthesis cup parallel to the proximal joint surface of the trapezium is essential for stability and the prevention of dislocation. This is a challenging surgical step, particularly for surgeons new to this technique. Despite adequate positioning of the guidewire, misplacements of the cup may occur, necessitating intraoperative revision. MATERIAL AND METHODS: This study examined the deviations in cup and guidewire positioning in thumb carpometacarpal joint prosthesis implantations by inexperienced and experienced surgeons through radiological analysis of 65 prostheses. RESULTS: Both inexperienced and experienced surgeons achieved precise guidewire positioning with mean deviations of<2.2°. Inexperienced surgeons showed significantly larger cup deviations in the dorsopalmar and lateral view (7.6±6.1° and 7.3±5.9°) compared with experienced surgeons (3.6±2.7° and 3.6±2.5°; p=0.012, p=0.017). The deviation of the cup position exhibited by inexperienced surgeons tends to be in the direction opposite to the initial guidewire position (p<0.0038). CONCLUSION: The results highlight the current challenges in cup positioning depending on a surgeon's level of experience, questioning the reliability of the current guidewire placement.

[Current Trends in the Implantation of the Touch Prosthesis at the Thumb Carpometacarpal Joint: Results of the 1st German-Speaking User Meeting]. / Aktuelle Trends bei der Implantation der Touch-Prothese am Daumensattelgelenk: Ergebnisse des 1. deutschsprachigen Anwendertreffens.

The introduction of the new generation of thumb carpometacarpal (CMC I) joint implants for the treatment of CMC I osteoarthritis has significantly broadened the scope of hand surgery in recent years. However, the technical demands of the procedure and the many details that need to be considered require appropriate training and a learning curve. To share experiences with the Touch CMC I prosthesis, we held the first German-speaking CMC I joint prosthetics user meeting in Zurich. After some basic introductory lectures on biomechanics and the principles of prosthetic fitting of the CMC I joint, the various challenges associated with CMC I joint prosthetics were discussed in interactive expert panels. Subsequently, cases were discussed in small groups under expert guidance and the respective conclusions were discussed in plenary. The main results of this symposium are summarised in this manuscript.

Evaluating initial usability of a hand augmentation device across a large and diverse sample.

The advancement of motor augmentation and the broader domain of human-machine interaction rely on a seamless integration with users' physical and cognitive capabilities. These considerations may markedly fluctuate among individuals on the basis of their age, form, and abilities. There is a need to develop a standard for considering these diversity needs and preferences to guide technological development, and large-scale testing can provide us with evidence for such considerations. Public engagement events provide an important opportunity to build a bidirectional discourse with potential users for the codevelopment of inclusive and accessible technologies. We exhibited the Third Thumb, a hand augmentation device, at a public engagement event and tested participants from the general public, who are often not involved in such early technological development of wearable robotic technology. We focused on wearability (fit and control), ability to successfully operate the device, and ability levels across diversity factors relevant for physical technologies (gender, handedness, and age). Our inclusive design was successful in 99.3% of our diverse sample of 596 individuals tested (age range from 3 to 96 years). Ninety-eight percent of participants were further able to successfully manipulate objects using the extra thumb during the first minute of use, with no significant influences of gender, handedness, or affinity for hobbies involving the hands. Performance was generally poorer among younger children (aged ≤11 years). Although older and younger adults performed the task comparably, we identified age costs with the older adults. Our findings offer tangible demonstration of the initial usability of the Third Thumb for a broad demographic.

An unusual configuration of two anomalies in the extensor digitorum profundus complex in a human.

The extensor digitorum profundus complex underwent degeneration of the ulnar segments during primate adaptation and evolution. This process resulted in the preservation of only the extensor pollicis longus and extensor indicis in some apes, including humans. Consequently, anatomical variations within the digitorum profundus complex in modern humans have been well-documented, with detailed reports on their frequency and patterns in previous studies. Here, we report an unusual arrangement involving two anomalies in the extensor digitorum profundus complex, identified in a 66-year-old Japanese male cadaver. In this cadaver, two accessory muscles differentiated from both the extensor pollicis longus and extensor indicis. Notably, the latter muscle featured a tendon bifurcating towards both the thumb and index fingers, referred to as the extensor pollicis et indicis communis. Under the extensor retinaculum, the tendon of the accessory extensor pollicis longus passed through an independent compartment, whereas that of the extensor pollicis et indicis communis traversed a compartment shared by the extensor indicis and the extensor digitorum communis. Both muscles were innervated by the posterior interosseous nerve. Previous studies have reported that the accessory slip of the extensor pollicis longus and extensor pollicis et indicis communis appear at frequencies of 0.6% and 0.4-1.4%, respectively. However, to the best of our knowledge, a configuration in which both appear simultaneously has not been reported. The data from this case could provide essential insights into the variations in the extensor digitorum profundus complex in humans and non-human primates.

The passive biomechanics of the thumb carpometacarpal joint: An in vitro study.

The thumb carpometacarpal (CMC) joint facilitates multidirectional motion of the thumb and affords prehensile power and precision. Traditional methods of quantifying thumb CMC kinematics have been largely limited to range-of-motion (ROM) measurements in 4 orthogonal primary directions (flexion, extension, abduction, adduction) due to difficulties in capturing multidirectional thumb motion. However, important functional motions (e.g., opposition) consist of combinations of these primary directions, as well as coupled rotations (internal and external rotation) and translations. Our goal was to present a method of quantifying the multidirectional in vitro biomechanics of the thumb CMC joint in 6 degrees-of-freedom. A robotic musculoskeletal simulation system was used to manipulate CMC joints of 10 healthy specimens according to specimen-specific joint coordinate systems calculated from computed tomography bone models. To determine ROM and stiffness (K), the first metacarpal (MC1) was rotated with respect to the trapezium (TPM) to a terminal torque of 1 Nm in the four primary directions and in 20 combinations of these primary directions. ROM and K were also determined in internal and external rotation. We found multidirectional ROM was greatest and K least in directions oblique to the primary directions. We also found external rotation coupling with adduction-flexion and abduction-extension and internal rotation coupling with abduction-flexion and adduction-extension. Additionally, the translation of the proximal MC1 was predominantly radial during adduction and predominantly ulnar during abduction. The findings of this study aid in understanding thumb CMC joint mechanics and contextualize pathological changes for future treatment improvement.

A Delayed Diagnosis of Bilateral Pediatric Trigger Thumbs: A Case Report and Literature Review.

We describe the case of a 6-year-old female who presented with tender nodules and fixed flexion of her thumbs, diagnosed as bilateral pediatric trigger thumb. Though present since infancy, her condition was not diagnosed in prior clinical visits. Pediatric trigger digit is a clinical diagnosis, often missed if the digit's range of motion is not assessed routinely. Given the duration, pain, and severity of her condition, conservative management was deferred, and she was referred for surgery. An approach to clinical management is discussed. Ultimately, further study is required to develop structured management guidelines for pediatric trigger digit.

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).

Comparison of Long-Term Healthcare Cost and Utilisation of Nonoperative and Surgical Management of Thumb CMC Arthritis.

Background: Thumb carpometacarpal joint (CMC) osteoarthritis is the most symptomatic hand arthritis but the long-term healthcare burden for managing this condition is unknown. We sought to compare total healthcare cost and utilisation for operative and nonoperative treatments of thumb CMC arthritis. Methods: We conducted a retrospective longitudinal analysis using a large nationwide insurance claims database. A total of 18,705 patients underwent CMC arthroplasty (trapeziectomy with or without ligament reconstruction tendon interposition) or steroid injections between 1 October 2015 and 31 December 2018. Primary outcomes, healthcare utilisation and costs were measured from 1 year pre-intervention to 3 years post-intervention. Generalised linear mixed effect models adjusted for potentially confounding factors such as the Elixhauser comorbidity score with propensity score matching were applied to evaluate the association between the primary outcomes and treatment type. Results: A total of 13,646 patients underwent treatment through steroid injections, and 5,059 patients underwent CMC arthroplasty. At 1 year preoperatively, the surgery group required $635 more healthcare costs (95% CI [594.28, 675.27]; p < 0.001) and consumed 42% more healthcare utilisation (95% CI [1.38, 1.46]; p < 0.0001) than the steroid injection group. At 3 years postoperatively, the surgery group required $846 less healthcare costs (95% CI [-883.07, -808.51], p < 0.0001) and had 51% less utilisation (95% CI [0.49, 0.53]; p < 0.0001) annually. Cumulatively over 3 years, the surgical group on average was $4,204 costlier than its counterpart secondary to surgical costs. Conclusions: CMC arthritis treatment incurs high healthcare cost and utilisation independent of other medical comorbidities. At 3 years postoperatively, the annual healthcare cost and utilisation for surgical patients were less than those for patients who underwent conservative management, but this difference was insufficient to offset the initial surgical cost. Level of Evidence: Level III (Therapeutic).

Isolated Palsy of the Anterior Interosseous Nerve to Flexor Pollicis Longus, Magnetic Resonance Imaging and Clinical Correlation: A Case Report.

CASE: Anterior interosseous nerve (AIN) palsy is an uncommon, though well-described, clinical entity. When isolated to the thumb, it can be confused with atraumatic rupture of the flexor pollicis longus (FPL) tendon. A 57-year-old man experienced atraumatic onset of difficulty flexing the distal interphalangeal thumb joint. Magnetic resonance imaging (MRI) demonstrated denervation edema of the FPL, suggesting atypical AIN palsy. Resolution of symptoms and MRI findings occurred concomitantly with nonoperative treatment. CONCLUSION: Atypical AIN palsy limited to the FPL is a rare clinical entity whose diagnosis can be supported with MRI. Here, we report a successful case of nonoperative management.

Volar dislocation of the metacarpophalangeal joint of the thumb: open reduction and repair of the ulnar collateral ligament. A case report.

INTRODUCTION: metacarpophalangeal dislocations of the thumb are not very frequent injuries, it is necessary to know the anatomy of the region to know possible causes of interposition that prevent a closed reduction of this pathology. CASE PRESENTATION: we present the case of a 75-year-old woman with a post-traumatic metacarpophalangeal dislocation of the thumb that required open reduction and surgical repair. In this procedure, we performed reduction of the dislocation, mobilization of the interposed structures, repair of the capsule and reinsertion of the ulnar collateral ligament. The early mobilization protocol helped to obtain very good results. CONCLUSION: it is imperative to consider possible associated injuries during the acute phase to achieve optimal short, medium, and long-term outcomes for our patients. A comprehensive and proactive approach to diagnosis and treatment is vital in effectively addressing this pathology and minimizing its potential sequelae.

INTRODUCCIÓN: las luxaciones metacarpofalángicas del pulgar no son lesiones muy frecuentes, es necesario conocer la anatomía de la región para conocer posibles causas de interposición que impidan una reducción cerrada de esta patología. PRESENTACIÓN DEL CASO: presentamos el caso de una mujer de 75 años con luxación metacarpofalángica postraumática del pulgar que requirió reducción abierta y reparación quirúrgica. En este procedimiento realizamos reducción de la luxación, movilización de las estructuras interpuestas, reparación de la cápsula y reinserción del ligamento colateral cubital. El protocolo de movilización temprana ayudó a obtener muy buenos resultados. CONCLUSIÓN: es imperativo considerar posibles lesiones asociadas durante la fase aguda para lograr resultados óptimos a corto, mediano y largo plazo para nuestros pacientes. Un enfoque integral y proactivo del diagnóstico y tratamiento es vital para abordar eficazmente esta patología y minimizar sus posibles secuelas.

Osteoblastoma of the thumb with a novel PRSS44::ALK fusion and literature review of osteoblastoma of hands and feet bones.

Osteoblastomas (OBs) are benign neoplasms constituting approximately 1% of primary bone tumors with a predilection for the spine and sacrum. We describe an OB of the proximal phalanx of the left thumb in a 38-year-old female. MRI of left hand demonstrated a 29-mm mildly expansile enhancing lesion involving the entire proximal phalanx of the first digit. Histology displayed a bone-forming tumor consisting of trabeculae of remodeled woven bone framed by plump osteoblasts in a vascularized background. Next-generation sequencing analysis identified a PRSS44::ALK fusion gene.

Three-dimensional motion analysis of pre- and postoperative thumb movement in trapeziometacarpal joint osteoarthritis-Comparison of arthrodesis and trapeziectomy with suspensionplasty.

Trapeziometacarpal osteoarthritis (TMC-OA) reduces the range of motion (ROM) of the thumb. However, the kinematic change achieved through surgical treatment remains unclear. Therefore, to quantify the kinematic change following TMC-OA surgery, we performed a three-dimensional motion analysis of the thumb using an optical motion capture system preoperatively and 1 year postoperatively in 23 patients with TMC-OA scheduled for arthrodesis (AD) or trapeziectomy with suspensionplasty (TS). Eighteen hands of nine healthy volunteers were also included as controls. Both procedures improved postoperative pain and Disability of the Arm, Shoulder and Hand scores, and AD increased pinch strength. The ROM of the base of the thumb was preserved in AD, which was thought to be due to the appearance of compensatory movements of adjacent joints even if the ROM of the TMC joint was lost. TS did not improve ROM. Quantifying thumb kinematic changes following TMC-OA surgery can improve our understanding of TMC-OA treatment and help select surgical procedures and postoperative assessment.

Application of extended ulnar parametacarpal perforator free flap for the reconstruction of total pulp defect of the thumb: A case report.

Many procedures are available for the coverage of thumb pulp defects; however, to gain thumb function and esthetics, a similar tissue is desirable. If the length of the longitudinal defect is <2 cm, a volar advancement flap is appropriate; however, if the flap is >2 cm long or wider, retrograde or free flaps are required. Here, we present a case of thumb pulp reconstruction using an extended ulnar parametacarpal perforator (UPM) flap, which achieved excellent functional and esthetic outcomes. A 46-year-old man underwent reconstruction surgery of his thumb, which was a degloved total pulp. A sensate 5.2 × 3.2 cm UPM flap was designed on the ulnar side of the right palm and transferred to his thumb. The flap donor site was covered with a V-Y advancement flap on the dorsal side of the right hand. At 12 months postoperatively, the patient achieved a functional and natural thumb appearance with high satisfaction. The UPM flap can offer soft tissue similar to the pulp region in the digit without a palm scar at the donor site. This extended application is suitable for the reconstruction of a total pulp defect of the digit and is an alternative option for a hemi-pulp flap from the toe area.

Mid- and long-term clinical results of the Elektra and Moovis prosthesis for trapeziometacarpal joint replacement.

BACKGROUND: Total joint arthroplasty as a surgical treatment option for trapeziometacarpal joint arthritis is recently revived. The aim of this study is to report on mid- and long-term results of the Elektra (single-mobility) and Moovis (dual-mobility) prosthesis for treatment of primary thumb carpometacarpal joint arthritis. METHODS: In this retrospective, monocentric, descriptive cohort study, 31 prostheses were evaluated that were implanted by a single surgeon in 26 patients between 2009 and 2019. Indication for surgery was trapeziometacarpal joint osteoarthritis (Eaton/Littler Stage II and III). Clinical and radiological follow-up was performed at a minimum of 24 months. The postoperative assessment included range of motion, pain, strength as well as functional scores (DASH, MHQ). Implant survival and complications were the primary endpoints. RESULTS: 10 Elektra and 21 Moovis prostheses were implanted between 2009 and 2019 with a mean follow-up of 74.2 months in the Elektra and 41.4 months in the Moovis group. The average patients' age at surgery was 64 years. Postoperative pain levels (VAS 0-10) were below 2 at rest and under stress in both groups. Grip/pinch strength and range of motion showed results comparable to the contralateral hand. Opposition was excellent with an average Kapandji index of 9.6 in both groups. Elektra achieved slightly better functional scores in the DASH and MHQ score. Satisfaction was high in both groups, and 96% of the patients would recommend the procedure. Metacarpophalangeal hyperextension > 15° was seen in 3 patients per group preoperatively and was corrected to < 5° post-surgery. 3 Elektra prostheses were revised due to cup loosening and dislocation for cup and/or neck replacement or secondary trapeziectomy. 1 Moovis prosthesis was revised with an exchange of the neck to a larger size due to restricted movement. After the mean follow-up of 7.9 years in Elektra and 3.5 years in MOOVIS, cumulative survival was 68.6% vs. 95.2%, respectively. CONCLUSIONS: In this mid- to long-term retrospective analysis, total joint arthroplasty in primary trapeziometacarpal joint arthritis results in low pain levels, excellent mobility and clinical function. Patient satisfaction is overall high. While revision due to cup loosening occurred more often in patients with single-mobility implants, no cases of dislocation or loosening of components were observed in the dual-mobility group. TRIAL REGISTRATION: The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of the Medical Faculty of Heidelberg University, reference number S-150/2020.

Arthrodesis of distal interphalangeal and thumb interphalangeal joint: a retrospective cohort study of 149 cases.

BACKGROUND: Arthrodesis of finger joints is often the last line of treatment of severe pain due to osteoarthritis, rheumatoid arthritis, or mallet finger. At the Department of Orthopedic and Hand Surgery, Örebro University Hospital (ÖUH) in Sweden, the Kirschner-wire technique was standard until 2020, when the headless compression screw technique was introduced as a complement. There is no consensus on which method is superior. The purpose of this study was to examine the outcomes and complications associated with distal interphalangeal (DIP) joint and thumb interphalangeal (IP) joint arthrodesis, and to see whether these correlated with patient-dependent and treatment-related factors. METHODS: In a retrospective cohort study, we evaluated a total of 149 consecutive arthrodeses (118 DIP joint and 31 thumb IP joint) performed between 2012 and 2022. The primary outcome was risk factors for complications after arthrodesis. RESULTS: Osteoarthritis was the most common indication (56%) for arthrodesis. The majority of the patients were females (74%), and the median age was 62 (range 18-86). The complication frequency was 35%, with infection being the most common (25%). Time to completed follow up was < 12 weeks in the majority of the cases (58%). There were no significant differences in complication rate between the 136 joints operated using Kirschner wire and the 13 joints operated using headless compression screws. There was no significant increased risk of complications among smokers or patients with rheumatoid arthritis. Diabetes and surgeon experience had a significant influence on the risk of complication (p = 0.036 and p = 0.006, respectively). CONCLUSIONS: Osteoarthritis was the most common indication for arthrodesis and postoperative complications occurred at a rate similar to that reported in the existing literature. Diabetes and surgeon experience were identified as factors increasing the risk of postoperative complications in these DIP/thumb IP joint arthrodeses. However, there was no significant difference between the two techniques (Kirschner wire and headless compression screws) regarding complications. Further studies are needed in order to determine the optimal type of operation and choice of implant. TRIAL REGISTRATION: Researchweb CRIS #280,998, 26th of July 2023.

Provision of a Home-Based Video-Assisted Therapy Program Is Noninferior to In-Person Hand Therapy After Thumb Carpometacarpal Arthroplasty.

BACKGROUND: In-person hand therapy is commonly prescribed for rehabilitation after thumb carpometacarpal (CMC) arthroplasty but may be burdensome to patients because of the need to travel to appointments. Asynchronous, video-assisted home therapy is a method of care in which videos containing instructions and exercises are provided to the patient, without the need for in-person or telemedicine visits. The purpose of the present study was to evaluate the effectiveness of providing video-only therapy (VOT) as compared with scheduled in-person therapy (IPT) after thumb CMC arthroplasty. METHODS: We performed a single-site, prospective, randomized controlled trial of patients undergoing primary thumb CMC arthroplasty without an implant. The study included 50 women and 8 men, with a mean age of 61 years (range, 41 to 83 years). Of these, 96.6% were White, 3.4% were Black, and 13.8% were of Hispanic ethnicity. The primary outcome measure was the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity (UE) score. Subjects in the VOT group were provided with 3 videos of home exercises to perform. Subjects in the control group received standardized IPT with a hand therapist. Improvements in the PROMIS UE score from preoperatively to 12 weeks and 1 year postoperatively were compared. RESULTS: Fifty-eight subjects (29 control, 29 experimental) were included in the analysis at the 12-week time point, and 54 (27 control, 27 experimental) were included in the analysis at the 1-year time point. VOT was noninferior to IPT for the PROMIS UE score at 12 weeks and 1 year postoperatively, with a difference of mean improvement (VOT - IPT) of 1.5 (95% confidence interval [CI], -3.6 to 6.6) and 2.2 (95% CI, -3.0 to 7.3), respectively, both of which were below the minimal clinically important difference (4.1). Patients in the VOT group potentially saved on average 201.3 miles in travel. CONCLUSIONS: VOT was noninferior to IPT for upper extremity function after thumb CMC arthroplasty. Time saved in commutes was considerable for those who did not attend IPT. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.