OBJECTIVE: Total joint arthroplasty (TJA) has often been used to treat thumb carpometacarpal (CMC) osteoarthritis (OA). However, guidelines for the CMC prosthesis shape remain unclear. This study aimed to identify the effective shape of a ball-and-socket prosthesis in restoring the range of thumb motion after TJA.
METHODS: The participants were 10 healthy young adult men (22-32 years; 26.8 ± 3.57 [mean ± SD]). CT scans were performed in eight static limb positions during abduction and flexion. We defined three design variables (offset R, height H, and neck rotation angle Φ) as the variables that determine the basic shape of the ball-and-socket prosthesis. The ideal values of these design variables were examined based on the results of a 3D motion analysis, which evaluated the change in the posture of the first metacarpal (r, h, and φ corresponding to R, H, and Φ, respectively) relative to the center of rotation (COR) during abduction and flexion. We also simulated the effect of these design variables on the range of thumb motion after TJA using 3D CAD.
RESULTS: We found that the values of r and h averaged over all limb positions were 6.92 ± 1.60 mm and 51.02 ± 1.67 mm, respectively, showing that these values remained constant regardless of limb position. In contrast, φ changed significantly. The simulation results indicated that Φ affected the range of thumb motion after TJA, and Φ = 0° relatively reproduced all limb positions compared to other values.
CONCLUSIONS: Our results suggested that the desirable values of R and H were the average of r and h over several limb positions and that Φ = 0° was effective in restoring the range of thumb motion after TJA. Our results will provide surgeons with new guidelines for selecting a prosthesis.

Background: Arthroscopic debridement is increasingly being utilised in patients with early-stage first carpometacarpal joint (FCMCJ) arthritis but has limited supportive evidence. This systematic review evaluates the literature, and reports on outcomes and adverse events following this procedure. Methods: An electronic literature search of PubMed, Embase, Medline and Cochrane Central, looking for studies describing outcomes following arthroscopic debridement in FCMCJ arthritis, was performed in November 2022. Studies where bony resection or interposition was performed as adjuncts were excluded. Reported outcomes included visual analogue scores (VAS) for pain; Disabilities of Arm, Shoulder and Hand (DASH) scores; pinch and grip strength; complications and re-operations. Results: Out of a total of 90 studies revealed from the search, only two studies were eligible for inclusion, with a cohort of 34 patients. Following arthroscopic debridement for FCMCJ osteoarthritis, the mean VAS improved by four units, mean DASH by 22 points, grip strength by 4.5 kg and pinch strength by 2 kg at mean follow-up of 18 months. The pooled complication and re-operation rates were 8.8% and 23.5%, respectively. Conclusions: There is a lack of evidence supporting the utility of FCMCJ arthroscopy and debridement in the management of patients with early arthritis. Although the limited evidence suggests that there may be some therapeutic benefit, further large-scale prospective studies need to be performed before making conclusive recommendations. Level of Evidence: Level III (Therapeutic).

OBJECTIVE: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.
CONCLUSIONS: Trapeziectomy with WALANT for TMJ OA is safe, preferred by patients and has similar clinical outcome as trapeziectomy in general anesthesia.
BACKGROUND: trapeziectomy, osteoarthritis, WALANT.

BACKGROUND: The trapeziometacarpal (TMC) joint is a complex joint, whose anatomy and function are different from the metacarpophalangeal joints of the long fingers. The stability of this joint is ensured at three levels by multiple structures: osteochondral, capsulo-ligamentous, and musculo-tendinous. The anatomical and biomechanical structures ensuring the stability of the TMC joint are perfectly evaluated on magnetic resonance imaging (MRI), with a high degree of confidence. All described ligaments are anatomically visible and perfectly assessed on MRI and ultrasound (US): the dorsoradial ligament, the posterior oblique ligament, the intermetacarpal ligament, the ulnar collateral ligament, the two bundles of the anterior oblique ligament (break ligament), as well as the superficial anterior oblique and deep anterior oblique ligaments.
METHODS: This educational review assesses the TMC joint anatomy using high-field MRI and US compared with cadaveric specimens as well the biomechanics of this joint. In addition, it highlights pathological patterns of traumatic (sprain, dislocation, and fractures) and degenerative diseases.
CONCLUSIONS: Knowledge of TMC joint anatomy is crucial to the radiologists\' understanding and assessment of various traumatic and degenerative pathologies, and thus helps clinicians and surgeons choose the appropriate treatment.

OBJECTIVE: Thumb carpometacarpal (CMC) joint osteoarthritis (OA) is increasingly treated with total joint arthroplasty (TJA). We aimed to perform a systematic review and meta-analysis of the benefits and harms of the TJA for thumb CMC OA compared with other treatment strategies.
METHODS: We performed a systematic search on MEDLINE and CENTRAL databases on August 2, 2023. We included randomized controlled trials investigating the effect of TJA in people with thumb CMC joint OA regardless of the stage or etiology of the disease or comparator. The outcomes were pooled with a random effect meta-analysis.
RESULTS: We identified 4 studies randomizing 420 participants to TJA or trapeziectomy. At 3 months, TJA\'s benefits for pain may exceed the clinically important difference. However, after 1-year follow-up TJA does not improve pain compared with trapeziectomy (mean difference 0.53 points on a 0 to 10 scale; 95% confidence interval [CI] 0.26-0.81). Furthermore, it provides a transient benefit in hand function at 3 months (measured with Disabilities of Arm, Shoulder, and Hand questionnaire, scale 0-100, lower is better) compared with trapeziectomy with or without ligament reconstruction tendon interposition. The benefit in function diminished to a clinically unimportant level at 1-year follow-up (4.4 points better; CI 0.42-8.4).
CONCLUSIONS: Transient benefit in hand function for TJA implies that it could be a preferable option over trapeziectomy for people who consider fast postoperative recovery important. However, current evidence fails to inform us if TJA carries long-term higher risks of revisions compared with trapeziectomy.

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.
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).
CONCLUSIONS: 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.
UNASSIGNED: Die zunehmende Anwendung von Daumensattelgelenksprothesen bei fortgeschrittener Rhizarthrose reflektiert den Erfolg der jüngsten Prothesengenerationen durch ihre verbesserten funktionellen Ergebnisse und geringeren Komplikationsraten. Eine präzise Ausrichtung der Prothesenpfanne parallel zur proximalen Gelenkoberfläche des Trapeziums ist hierbei für die Stabilität und Vermeidung von Luxationen essenziell. Dies stellt gerade für den unerfahrenen „Beginner“ dieser Technik erfahrungsgemäß das größte Problem dar. Trotz adäquater Positionierung des Führungsdrahtes können Fehlplatzierungen der Pfanne auftreten, die eine intraoperativen Revision notwendig machen.
METHODS: Diese Studie untersucht die Abweichungen der Pfannen- und Führungsdrahtpositionierung bei Daumensattelgelenksprothesenimplantationen durch unerfahrene und erfahrene Operateure mittels radiologischer Analyse an 65 Prothesen.
UNASSIGNED: Sowohl unerfahrene als auch erfahrene Operateure erreichten eine präzise Führungsdrahtpositionierung mit mittleren Abweichungen von<2,2°. Unerfahrene zeigten signifikant größere Pfannenabweichungen im dorsopalmaren und lateralen Strahlengang (7,6±6,1° und 7,3±5,9°) im Vergleich zu erfahrenen Operateuren (3,6±2,7° und 3,6±2,5°; p=0,012, p=0,017). Die Abweichung der Pfanne zeigte bei unerfahrenen Operateuren eine jeweils entgegengesetzte Richtungstendenz zum Führungsdraht (p<0,0038).
UNASSIGNED: Die Ergebnisse verdeutlichen die aktuellen Herausforderungen bei der Pfannenpositionierung abhängig vom Erfahrungsgrad des Chirurgen und hinterfragen die Zuverlässigkeit des aktuellen Führungsdrahtsystems bei Prothesenimplantationen.

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.
Durch die Einführung der neuesten Generation von Daumensattelgelenksprothesen zur Behandlung der Rhizarthrose hat sich das handchirurgische Behandlungsspektrum in den letzten Jahren deutlich erweitert. Der technische Anspruch dieser Operation und die vielen Details, die es zu beachten gilt, bedingen jedoch ein entsprechendes Training und eine damit verbundene Lernkurve. Um Erfahrungen mit der Touch Daumensattelgelenksprothese auszutauschen, haben wir das erste deutschsprachige Anwendertreffen zur Daumensattelgelenksprothetik in Zürich durchgeführt. Nach einigen grundlegenden Einführungsvorträgen zur Biomechanik und zu den Prinzipien der prothetischen Versorgung des Daumensattelgelenkes wurden in interaktiven Expertenrunden die verschiedenen Herausforderungen um die Daumensattelgelenksprothetik diskutiert. Anschließend wurden in Kleingruppen unter kundiger Leitung Fälle besprochen und die jeweiligen Konklusionen im Plenum diskutiert. Die wesentlichen Ergebnisse dieses Symposiums sind in diesem Manuskript zusammengefasst.

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.
Die Daumensattelgelenksarthrose stellt die häufigste operationsbedürftige Arthrose an der Hand dar, wenngleich vor jeder operativen Therapie immer die konservativen Maßnahmen ausgereizt werden sollen. Wird bei Fortschreiten der Gelenkabnutzung jedoch anhaltend die Funktion des Daumens und somit der gesamten Hand schmerzbedingt eingeschränkt, ist eine chirurgische Behandlung indiziert. Bereits 1947 publizierte Gervis Ergebnisse nach Entfernung des Trapeziums und leitete damit die Entwicklung einer Vielzahl unterschiedlicher Operationsverfahren ein. Das Hauptproblem nach Resektionsarthoplastiken mit oder ohne Sehneninterposition und/oder Suspension stellt nach wie vor die sehr lange Rehabilitationszeit dar. Nach der Einführung der ersten Prothese des Daumensattelgelenkes durch De la Caffiniere vor 50 Jahren kam es zu einer raschen Entwicklung hin zu den aktuellen modularen, bipolaren Implantaten. Vor allem im deutschsprachigen Raum besteht nach wie vor eine gewisse Skepsis bezüglich der Prothesen, weshalb diese Arbeit beide chirurgischen Verfahren mit besonderem Augenmerk auf die Aspekte der Indikationsstellung beleuchten soll.

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.

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).