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

PURPOSE OF THE STUDY: 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. MATERIAL AND 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. DISCUSSION: 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. KEY WORDS: trapeziectomy, osteoarthritis, WALANT.

Secondary Linburg-Comstock syndrome post-trapeziectomy surgery.

Linburg-Comstock syndrome is an acquired symptomatic restrictive thumb index finger flexor tenosynovitis involving a hypertrophic tenosynovium between flexor pollicis longus and flexor digitorum profundus. Patients may report synkinetic movement of the thumb and index finger, pain and swelling. We present the case of a woman in her 80s who presented with painless Linburg-Comstock syndrome after a trapeziectomy 4 months earlier for trapeziometacarpal arthritis. A literature review of PubMed-indexed case reports found that Linburg-Comstock syndrome has never been described in a post-trapeziectomy patient. This unusual presentation that arose as a side effect of hand surgery remains unreported in the literature. We present this unique complication as the first such case in the world. This case report is a valuable addition to the existing knowledge on the complications of trapeziectomy surgery.

[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.

Total joint arthroplasty for thumb carpometacarpal joint osteoarthritis: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND PURPOSE: 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. PATIENTS AND 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). CONCLUSION: 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.

Arthroscopically Assisted Treatment of Isolated Comminuted Trapezium Fracture: A Report of Two Cases.

CASES: Two competitive athletes with isolated comminuted trapezium fractures, sustained during American football and rugby, presented with pain and swelling of the first metacarpal base. Computed tomography confirmed isolated comminuted trapezium fractures. Arthroscopic reduction of displacement with screw fixation below the articular surface was performed through a small incision. Both patients returned to their preinjury sports levels within 2 months postoperatively. CONCLUSION: Arthroscopic treatment of isolated comminuted trapezium fractures achieved accurate reduction of articular surface displacement and preserved trapeziometacarpal joint stability with minimal soft-tissue invasion. This facilitated an early return to contact sports for the affected athletes.

Computer-simulated TOUCH prosthesis cup malposition and solutions.

INTRODUCTION: Total joint replacement has become significantly more common as a treatment for advanced trapeziometacarpal joint osteoarthritis in recent years. The latest generation of prostheses with dual-mobility designs leads to very good functional results and low rates of loosening and dislocation in the short and medium term. Biomechanical studies showed that central placement and parallel alignment of the cup with respect to the proximal articular surface of the trapezium are crucial for both cup stability and prevention of dislocation. Despite correct positioning of the guidewire, incorrect placement or tilting of the inserted cup may occur, requiring immediate intraoperative revision. METHODS: The existing spherical and conical cup models in sizes 9 mm and 10 mm were transferred to a computer-aided design dataset. Depending on the intraoperative complication (tilting or incorrect placement), the revision options resulting from the various combinations of cup type and size were simulated and analyzed according to the resulting defect area and bony contact area. RESULTS: In well centered cups, a size 9 conical cup could be replaced by a size 9 spherical cup and still be fixed by press-fit. Conversely, a size 9 spherical cup could not be replaced by a size 9 conical cup, but only by a size 10 cup, of whatever shape. When a size 9 conical cup was tilted up to 20°, the best revision option was to resect the sclerotic margin and insert a size 10 conical cup deeper into the cancellous bone, to achieve the largest contact area with the surrounding bone. When a size 9 cup of whatever shape was poorly centered (misplaced with respect to the dorsopalmar or radioulnar line of the trapezium), placement should be corrected using a size 10 cup, combined with autologous bone grafting of the defect. Again, the size 10 conical cup showed the largest bony contact area. CONCLUSION: Our computer-based measurements suggested options for intraoperative cup revision depending on cup shape and size and on type of misalignment with resulting bone defects. These suggestions, however, need to be confirmed in anatomic specimens before introducing them into clinical practice.

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.

De Quervain tendinitis after total trapeziometacarpal joint arthroplasty: Biomechanical evaluation of tendon excursion in the first extensor tendon compartment.

De Quervain's tenosynovitis is the most common complication after total trapeziometacarpal joint replacement. Etiology is unclear. Implantation of a ball-in-socket implant changes the biomechanics of the normal trapeziometacarpal saddle joint and increases its range of motion. The present study demonstrates that this procedure also significantly increases excursion of the abductor pollicis longus and extensor pollicis brevis tendons during thumb flexion-extension, and not during thumb abduction-adduction. Increased tendon gliding under the retinaculum of the first extensor tendon compartment could predispose to the development frictional tenosynovitis and play a role in the development of de Quervain's syndrome after total trapeziometacarpal joint replacement. LEVEL OF EVIDENCE: Not applicable (laboratory study).

Treatment of trapeziometacarpal osteoarthritis with a pyrocarbon implant: Long-term results.

OBJECTIVE: Trapeziometacarpal osteoarthritis is the second most common degenerative articular disease. Although initial therapy should be conservative, surgical treatment is often required. Several surgical techniques have been described, but none has proved to be a gold-standard. The objective of this study was to evaluate the long-term clinical and radiological results of trapeziometacarpal interposition arthroplasty with the PyroDisk implant (Integra LifeSciences). METHODS: A retrospective long-term study of all patients who underwent trapeziometacarpal interposition arthroplasty with a pyrocarbon implant at our institution was performed. RESULTS: Twenty-four patients who underwent PyroDisk (Integra LifeSciences). arthroplasty at our institution were identified; 7 were lost to follow-up; 17 patients were evaluated, for 20 arthroplasties. Mean follow-up was 13.5 years (range: 12-15 years). Disability in daily living activities was low (mean Disabilities of the Arm, Shoulder and Hand score, 29.6), with a mean pain score of 0.22. Mean Kapandji score at 13.5 years was 8.63. Mean grip strength was 18.5 kg and key-pinch strength 2.84 kg. Two patients had implant dislocation, needing revision surgery for implant removal. Implant survival rate was 88.9% at 13.5 years. CONCLUSIONS: Our study confirmed that good clinical results can be expected after interposition arthroplasty with PyroDisk (Integra LifeSciences). Regarding radiological findings, peri-implant osteolysis was present in 12 of the patients, but had no influence on the clinical outcome.

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.

Efficacy of Intra-Articular Corticosteroid Injection for Nonsurgical Management of Trapeziometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PURPOSE: As osteoarthritis (OA) of the trapeziometacarpal (TMC) joint leads to a high degree of disease burden with compromises in rudimentary and fine movements of the hand, intra-articular injections may be a desirable treatment option. However, because there are no evidence-based guidelines, the choice of intra-articular injection type is left to the discretion of the individual surgeon in collaboration with the patient. The purpose of our study was to perform a systematic review and meta-analysis using level I studies to compare outcomes following corticosteroid and alternative methods of intra-articular injections for the management of TMC OA. Our hypothesis was that intra-articular corticosteroid injections were no more effective than other methods of intra-articular injections for the management of TMC OA. METHODS: A systematic literature search was performed. Eligible for inclusion were randomized control trials reporting on intra-articular corticosteroid injection for the management of TMC OA. Clinical outcomes were recorded. RESULTS: The 10 included studies comprised 673 patients. The mean age was 57.8 ± 8.3 years, with a mean follow-up of 6.4 ± 2.7 months. There was no significant difference in visual analog scale scores, grip strength and tip pinch strength between corticosteroids and hyaluronic acid at short- and medium-term follow-up. Further, there was no difference in visual analog scale pain scores at rest at medium-term follow-up between corticosteroids and platelet-rich plasma. CONCLUSIONS: Despite short-term improvement with intra-articular corticosteroid injections, there was no significant difference in pain and functional outcomes following intra-articular corticosteroid injections compared to hyaluronic acid or platelet-rich plasma administration. Given the affordability, ease of administration, and efficacy associated with corticosteroids, they are a favorable option when considering the choice of intra-articular injection for the management of TMC OA. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Cost-effectiveness and cost-utility of the ball-and-socket trapeziometacarpal prosthesis compared to trapeziectomy and ligament reconstruction: study protocol for a randomized controlled clinical trial.

BACKGROUND: Trapeziometacarpal (TMC) osteoarthritis (OA) is a common cause of pain and weakness during thumb pinch leading to disability. There is no consensus about the best surgical treatment in unresponsive cases. The treatment is associated with costs and the recovery may take up to 1 year after surgery depending on the procedure. No randomized controlled trials have been conducted comparing ball and socket TMC prosthesis to trapeziectomy with ligament reconstruction. METHODS: A randomized, blinded, parallel-group superiority clinical trial comparing trapeziectomy with abductor pollicis longus (APL) arthroplasty and prosthetic replacement with Maïa® prosthesis. Patients, 18 years old and older, with a clinical diagnosis of unilateral or bilateral TMC OA who fulfill the trial's eligibility criteria will be invited to participate. The diagnosis will be made by experienced hand surgeons based on symptoms, clinical history, physical examination, and complementary imaging tests. A total of 106 patients who provide informed consent will be randomly assigned to treatment with APL arthroplasty and prosthetic replacement with Maïa® prosthesis. The participants will complete different questionnaires including EuroQuol 5D-5L (EQ-5D-5L), the Quick DASH, and the Patient Rated Wrist Evaluation (PRWE) at baseline, at 6 weeks, and 3, 6, 12, 24, 36, 48, and 60 months after surgical treatment. The participants will undergo physical examination, range of motion assessment, and strength measure every appointment. The trial's primary outcome variable is the change in the visual analog scale (VAS) from baseline to 12 months. A long-term follow-up analysis will be performed every year for 5 years to assess chronic changes and prosthesis survival rate. The costs will be calculated from the provider's and society perspective using direct and indirect medical costs. DISCUSSION: This is the first randomized study that investigates the effectiveness and cost-utility of trapeziectomy and ligament reconstruction arthroplasty and Maïa prosthesis. We expect the findings from this trial to lead to new insights into the surgical approach to TMC OA. TRIAL REGISTRATION: ClinicalTrials.gov NCT04562753. Registered on June 15, 2020.

The effect of trapeziometacarpal joint passive stiffness on mechanical loadings of cartilages.

Hypermobility of the trapeziometacarpal joint is commonly considered to be a potential risk factor for osteoarthritis. Nevertheless, the results remain controversial due to a lack of quantitative validation. The objective of this study was to evaluate the effect of joint laxity on the mechanical loadings of cartilage. A patient-specific finite element model of trapeziometacarpal joint passive stiffness was developed. The joint passive stiffness was modeled by creating linear springs all around the joint. The linear spring stiffness was determined by using an optimization process to fit force-displacement data measured during laxity tests performed on eight healthy volunteers. The estimated passive stiffness parameters were then included in a full thumb finite element simulation of a pinch grip task driven by muscle forces to evaluate the effect on trapeziometacarpal loading. The correlation between stiffness and the loading of cartilage in terms of joint contact pressure and maximum shear strain was analyzed. A significant negative correlation was found between the trapeziometacarpal joint passive stiffness and the contact pressure on trapezium cartilage during the simulated pinch grip task. These results therefore suggest that the hypermobility of the trapeziometacarpal joint could affect the contact pressure on trapezium cartilage and support the existence of an increased risk associated with hypermobility.

Basal thumb arthritis surgery: complications and its management.

The management of complications after surgery for basal thumb arthritis is sometimes challenging, and there are no clear recommendations on how to evaluate and manage patients with residual symptoms. The aim of the present article was to review the most common complications after surgery for basal thumb arthritis, with an emphasis on resection arthroplasty, joint replacement and joint fusion. In addition, possible management strategies for the different types of complications will be highlighted.

Predicting Contralateral Surgery for Trapeziometacarpal Arthrosis Within 5 Years.

PURPOSE: Symptomatic trapeziometacarpal (TMC) joint arthritis is a common cause of hand pain. It is unknown how many patients ultimately elect to have bilateral surgery for TMC arthritis. In this study, we assessed the frequency and predictive factors for contralateral TMC surgery in patients who underwent prior TMC surgery. METHODS: We identified 712 patients who underwent primary surgery for TMC arthritis with a follow-up period of 5 years. We collected demographic, surgical, and follow-up data. Prediction models for contralateral surgery using a training and testing data set were created with multivariable logistic regression and random forest classifier algorithms. RESULTS: At the time of initial surgery, 230 patients had bilateral thumb pain (32%), but only 153 patients ultimately had an operation for TMC arthritis on the contralateral side within 5 years (21% of 712 total patients and 67% of 230 patients with bilateral pain). Common predictive factors between both models for contralateral surgery were younger age (odds ratio [OR] = 0.95; 95% confidence interval [CI], 0.93-0.98), bilateral thumb pain (OR = 3.76; 95% CI, 2.52-5.65), and anxiety disorders (OR = 1.84; 95% CI, 1.11-3.03). CONCLUSIONS: In our study, we found that the rate of contralateral surgery was 21% in patients who underwent prior TMC surgery. Predictive factors for future contralateral surgery included younger age, bilateral thumb pain, and anxiety disorder at the time of initial surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Development of an implantable trapezium carpal bone replacement for measuring in vivo loads at the base of the thumb.

Understanding the loads that occur across musculoskeletal joints is critical to advancing our understanding of joint function and pathology, implant design and testing, as well as model verification. Substantial work in these areas has occurred in the hip and knee but has not yet been undertaken in smaller joints, such as those in the wrist. The thumb carpometacarpal (CMC) joint is a uniquely human articulation that is also a common site of osteoarthritis with unknown etiology. We present two potential designs for an instrumented trapezium implant and compare approaches to load calibration. Two instrumented trapezia designs were prototyped using strain gauge technology: Tube and Diaphragm. The Tube design is a well-established structure for sensing loads while the Diaphragm is novel. Each design was affixed to a 6-DOF load cell that was used as the reference. Loads were applied manually, and two calibration methods, supervised neural network (DEEP) and matrix algebra (MAT), were implemented. Bland-Altman 95% confidence interval for the limits of agreement (95% CI LOA) was used to assess accuracy. Overall, the DEEP calibration decreased 95% CI LOA compared with the MAT approach for both designs. The Diaphragm design outperformed the Tube design in measuring the primary load vector (joint compression). Importantly, the Diaphragm design permits the hermetic encapsulation of all electronics, which is not possible with the Tube design, given the small size of the trapezium. Substantial work remains before this device can be approved for implantation, but this work lays the foundation for further device development that will be required.

Complications of prosthesis versus trapeziectomy in trapeziometacarpal joint arthritis: A systematic review.

OBJECTIVE: Thumb osteoarthritis is a frequent pathology, mainly affecting the elderly. The surgical treatment initially described and having proved its worth is total trapeziectomy. Since the advent of trapeziometacarpal prostheses, several studies showed the non-inferiority of this technique on clinical criteria, with superiority in bone sparing, although neither technique demonstrated overall superiority. We therefore examined the specific complications of each surgical technique by analyzing their nature and prevalence through a review of the literature to compare them on these new parameters. METHODS: Seventy-four of the 320 articles reviewed were included, 38 of which concerned trapeziectomy, and 36 concerned prostheses, for a total of 4,865 patients. They were original studies, involving adults undergoing trapeziometacarpal arthroplasty or trapeziectomy, published after 2015, reporting at least one well-described complication. RESULTS: 6.13% of trapeziectomies presented severe complications (in particular thumb collapse and metacarpophalangeal hyperextension), 3.31% moderate complications and 1.90% minor complications, leading to a 2.0% revision rate. 23.88% of prostheses had severe complications (loosening, dislocation and wear), 5.06% moderate complications and 1.36% minor complications, leading to a 12.8% revision rate. In addition, we analyzed more recent prosthesis designs separately, and found lower prevalence of severe complications (16.56%) and revision surgery (4.3%). CONCLUSION: Revision surgery for trapeziometacarpal prostheses is usually only a standard trapeziectomy with the same follow-up as first-line trapeziectomy, whereas revision surgery for trapeziectomies is much more complex and the results are uncertain. For this reason, we would reserve total trapeziectomy for revision surgeries and patients with low functional demand for whom a second surgery is not desirable. Further studies could confirm this attitude, especially focusing on the latest generation of dual mobility implants.

Influence of the anatomy of the proximal articular surface of the trapezium (PAST) and the trapezoidal articular surface of the trapezium (TRAST) in cup placement during trapeziometacarpal arthroplasty.

The influence of the anatomy of the proximal articular surface of the trapezium (PAST) and the trapezoidal articular surface of the trapezium (TRAST) on cup placement during trapeziometacarpal arthroplasty was retrospectively evaluated on 56 preoperative anteroposterior radiographs of patients who underwent surgery for trapeziometacarpal osteoarthritis. The percentage coverage of the prosthetic cup by the PAST and the available height of the trapezium were calculated. In 39% of cases, there was a significant difference (up to a mean 4.5 mm, p < 0.001) between the radial height of the trapezium (which is usually considered) and the available height of the trapezium. The anatomy of the PAST and the TRAST has an impact on the placement of the prosthetic cup when trapezium height is low. The results of the present study suggest that these considerations must be known by all operators performing trapeziometacarpal arthroplasty; that lateralization, implant suspension, or surgical alternatives should be considered to prevent several intra- and postoperative surgical complications. Level of evidence: IV.

Does trapezium remodeling correlate with cup shape?

We investigated whether trapezium bone reaction was different following implantation of a trapeziometacarpal total joint replacement with a hemispheric or a conical cup. Fifty-three Keri Medical Touch implants with hemispheric cup and 53 with conical cup were prospectively followed up radiographically. We compared radiographs taken immediately and one year after surgery for cup subsidence, tilt, heterotopic ossification and loosening. Cup subsidence of at least 1 mm was detected in 4% of cases for both cup types. Additive bone reaction around the cup of more than 1 mm was present in 62% of conical cups and 47% of hemispheric cups. These were minor and there were no large ossifications with risk of impingement. Minor radiolucency was seen superficially at the implant-bone interface of 13% of the hemispheric cups and 9% of the conical cups. None of these bone reactions differed significantly according to cup design.