Do osteophytes alter thumb carpometacarpal Biomechanics? a preliminary in vitro study.

Osteoarthritis (OA) of the thumb carpometacarpal (CMC) joint is prevalent and debilitating, marked by substantial loss of range of motion (ROM) and overall function. CMC OA is associated with osteophyte growth, but the impact of this growth on CMC ROM has not been systematically characterized. Our goal was to determine whether osteophytes decrease CMC ROM and, if so, whether these decreases are direction-dependent. A robotic musculoskeletal simulation system was used to manipulate 18 CMC specimens with a range of joint health following three test protocols: (1) Rotational ROM in flexion, extension, abduction, adduction, and 20 combined directions, (2) Internal/External Rotation (IR/ER), and (3) Translational ROM in volar, dorsal, radial, ulnar, and 4 combined directions. Osteophyte volume (OV) was computed in total and by volar, dorsal, radial, and ulnar quadrants, and correlations with ROM were computed by direction and in total. We found that an increase in overall trapezial OV was associated with a reduction in overall rotational ROM and IR/ER, but not with translational ROM. We found decreased extension was associated with increased ulnar, volar, and radial OV, and decreased abduction was associated with increased volar OV. Decreased internal rotation was associated with increased ulnar, volar, and radial OV. The proposed method and findings of this pilot study will lay the groundwork for a larger investigation into the relationship between pathological structure and function in the CMC joint.

Thumb Carpometacarpal Joint Denervation for Early Osteoarthritis: An Overview of the Literature and a Pilot Study on Pain Reduction and Patient Satisfaction.

Background The treatment of patients with osteoarthritis of the first carpometacarpal joint (CMC-I) aims at pain reduction to improve hand function and quality of life. The CMC-I denervation procedure is relatively new and seems appealing, as it is minimally invasive and has few or no disadvantages. To date, however, little research has been done on the results of a CMC-I denervation. The aim of this study was to investigate whether denervation provides pain reduction in patients with early CMC-I osteoarthritis. Methods A literature search was done using PubMed. Studies were excluded if access to full text was not available, if the articles were written in other languages than Dutch or English, and if preoperative testing, follow-up testing, or reporting were incomplete. Studies were included if patients were older than 18 years, had primary CMC-I osteoarthritis with no other wrist pathology, and had received conservative treatment without sustained benefit. The Critical Appraisal Tools of the Joanna Briggs Institute were used for critical appraisal. Clinical data was gathered retrospectively from the medical records to identify patients who underwent CMC-I denervation in The Hand Clinic, Amsterdam. The data of 20 patients were analyzed. Pre- and postoperative visual analog scale (VAS) scores on pain, patient satisfaction, and complications were evaluated. Patients older than 18 years with primary CMC-I osteoarthritis stage I and II and no other wrist pathology, in whom conservative treatment failed were included in the study. Patients with CMC-I osteoarthritis stage III and IV were excluded. Results All 17 search results were screened for full text access, after which 6 case series, 4 systematic reviews, 1 cohort study, 1 comment, and 1 scoping review was included. All but one study showed pain reduction after surgery. In half of the studies, this difference was statistically significant. The average patient satisfaction in these studies was 84.1% and the complication rate was 13.4%. A total of 20 patients were included between 2019 and 2022, with a mean preoperative VAS for pain at rest of 48.2 ± 29.9. After surgery, this decreased to 35.8 ± 34.1. This difference was not statistically significant. The mean VAS for pain during use before denervation was 79 ± 18.4 and this decreased to 49.8 ± 34.2 postoperatively. This difference did appear to be statistically significant. The average patient satisfaction was 60%, and the complication rate was 10%. Conclusion This study provides a literature overview and a pilot study on pain reduction, patient satisfaction, and complications after denervation of the CMC-I joint in patients with early osteoarthritis. Our retrospective case series roughly mirrored the average results found in the literature. There was a statistically significant decrease in pain during use postoperatively. There was no statistically significant difference in pain at rest before and after surgery. The complications were mild and the complication rate was low; however, the average patient satisfaction rate was lower as compared to that reported in the literature.

A cross-sectional quantitative analysis of the readability and quality of online resources regarding thumb carpometacarpal joint replacement surgery.

Background: Thumb carpometacarpal (CMC) joint osteoarthritis is a common degenerative condition that affects up to 15 â€‹% of the population older than 30 years. Poor readability of online health resources has been associated with misinformation, inappropriate care, incorrect self-treatment, worse health outcomes, and increased healthcare resource waste. This study aims to assess the readability and quality of online information regarding thumb carpometacarpal (CMC) joint replacement surgery. Methods: The terms "thumb joint replacement surgery", "thumb carpometacarpal joint replacement surgery", "thumb cmc joint replacement surgery", "thumb arthroplasty", "thumb carpometacarpal arthroplasty", and "thumb cmc arthroplasty" were searched in Google and Bing. Readability was determined using the Flesch Reading Ease Score (FRES) and the Flesch-Kincaid Reading Grade Level (FKGL). FRES >65 or a grade level score of sixth grade and under was considered acceptable. Quality was assessed using the Patient Education Materials Assessment Tool (PEMAT) and a modified DISCERN tool. PEMAT scores below 70 were considered poorly understandable and poorly actionable. Results: A total of 34 websites underwent qualitative analysis. The average FRES was 54.60 â€‹± â€‹7.91 (range 30.30-67.80). Only 3 (8.82 â€‹%) websites had a FRES score >65. The average FKGL score was 8.19 â€‹± â€‹1.80 (range 5.60-12.90). Only 3 (8.82 â€‹%) websites were written at or below a sixth-grade level. The average PEMAT percentage score for understandability and actionability was 76.82 â€‹± â€‹9.43 (range 61.54-93.75) and 36.18 â€‹± â€‹24.12 (range 0.00-60.00) respectively. Although 22 (64.71 â€‹%) of websites met the acceptable standard of 70 â€‹% for understandability, none of the websites met the acceptable standard of 70 â€‹% for actionability. The average total DISCERN score was 32.00 â€‹± â€‹4.29 (range 24.00-42.00). Conclusions: Most websites reviewed were written above recommended reading levels. Most showed acceptable understandability but none showed acceptable actionability. To avoid the negative outcomes of poor patient understanding of online resources, providers of these resources should optimise accessibility to the average reader by using simple words, avoiding jargon, and analysing texts with readability software before publishing the materials online. Websites should also utilise visual aids and provide clearer pre-operative and post-operative instructions.

Physician practices in referring rheumatoid hand and thumb carpometacarpal arthritis cases to hand surgeons.

OBJECTIVES: To investigate the referral practices across different medical specialties and identify possible barriers to hand surgery referral. Rheumatoid hand deformities (RHDs) and thumb carpometacarpal (CMC) arthritis may require surgery once deformities occur. However, in Saudi Arabia, the rate of referrals to hand surgeons remains low. METHODS: This was a cross-sectional study that included 102 consultants of family medicine, rheumatology, and orthopedics across various regions of Saudi Arabia. A total of 30 institutions were contacted and requested to distribute a survey questionnaire to their physicians; these institutions included 8 private hospitals, 16 government hospitals, and 6 primary healthcare centers. The survey included questions on the incidence, rate, management, knowledge, and referral of patients with RHD and CMC arthritis using a 5-point Likert scale. The Kruskal-Wallis H test was utilized in our analysis to evaluate the differences in responses among the 3 specialties. RESULTS: For RHD and thumb CMC arthritis, the referral rate was higher among orthopedic surgeons compared to rheumatologists and family medicine physicians. The main barriers to referral were patient refusal, medical treatment alone being deemed adequate, and a lack of awareness of surgical options for management. CONCLUSION: Our findings highlight discrepancies in patterns of physician referral of RHD and thumb CMC arthritis cases to hand surgeons, indicating the need for targeted interventions to improve referral rates and enhance patient outcomes.

Three-Dimensional Analysis of the First Metacarpal Axes in Healthy Individuals and Early-Stage Thumb Carpometacarpal Osteoarthritis Patients-Potential Implication on First Metacarpal Corrective Osteotomy.

Background: Numerous anatomical features of the first carpometacarpal (CMC I) joint have been investigated as potential predispositions for CMC I osteoarthritis (OA). Even though load transmission through the CMC I joint-and, therefore, the development of osteoarthritis-is believed to be influenced by the geometry of the first metacarpal (MC I) bone, there is no common definition of the MC I axes. Methods: CT scans of twenty healthy volunteers and pre- and postoperative CT scans of six patients with CMC I OA undergoing Wilson osteotomy were analyzed. We proposed a calculation method based on anatomical landmarks for the proximal joint surface axis (PA) angle and the definition of an anatomical (AA) and a mechanical (MA) longitudinal axis. We hypothesized that for an MC I extension osteotomy to be effective, the AA and MA need to be aligned surgically. Results: To align AA and MA, an average correction angle of 22.60° (SD 2.53°) at 1 cm and 26.73° (SD 2.55°) at 1.5 cm distal to the CMC I joint line is required. Conclusions: The hereby proposed method for patient-specific calculation of the correction can be used to improve the surgical technique.

Comparison of mini-plate versus Kirschner wire internal fixation for fifth metacarpal basal fractures with carpometacarpal joint dislocation.

OBJECTIVE: To compare the outcome of mini-plate versus Kirschner wire (K-wire) internal fixation for treating fifth metacarpal basal fractures with carpometacarpal joint dislocation. METHOD: A total of 46 patients with fifth metacarpal basal fractures combined with carpometacarpal joint dislocation were divided into two groups. The control group received K-wire fixation, while the observation group underwent mini-plate fixation. We assessed treatment effectiveness, surgical parameters, range of motion, serum stress markers, quality of life scores, and postoperative complication rates. A multivariable logistic regression analysis was performed to identify factors influencing postoperative joint function. RESULTS: The observation group demonstrated a significantly higher excellent and good rate compared to the control group (P<0.05). Additionally, the observation group had a lower intraoperative bleeding volume, shorter incision lengths, and faster fracture healing times, all significant differences (all P<0.05). Postoperative assessments indicated that range of motion, quality of life scores, and superoxide dismutase levels were significantly improved in the observation group (P<0.05). Conversely, cortisol, angiotensin II, and norepinephrine levels, along with the incidence of postoperative complications, were lower in the observation group compared to the control group (all P<0.05). Logistic regression analysis identified the surgical method as an independent factor affecting postoperative metacarpal joint function (OR = 0.16, P = 0.003). CONCLUSION: Mini-plate internal fixation is superior to K-wire fixation for the treatment of fifth metacarpal basal fractures with carpometacarpal joint dislocation. It promotes faster fracture healing, reduces serum stress markers, enhances joint mobility and quality of life, and decreases postoperative complications.

Long-term results of 292 CarpoFit®-joint replacements for trapeziometacarpal osteoarthritis: a prospective cohort study with a 10-year follow-up.

We report a prospective consecutive series of CarpoFit® (Implantcast, Buxtehude, Germany) trapeziometacarpal prostheses used between 2006 and 2014 for 292 patients with stage I-III trapeziometacarpal arthritis who remained symptomatic after conservative treatment. Patients were assessed at 3 months, 6 months and 1 year postoperatively for thumb movement, pinch strength and by validated patient-derived outcome scores and radiographs. Follow-up at 5 and 10 years was by outcome scores alone. Complications and revisions were recorded. Of the patients, 91% were either satisfied or very satisfied with their treatment at 10 years. Pain relief and functional outcomes were significantly improved within 3 months. Results were sustained during the entire observation period. The implant survival was 95% after 10 years. Prosthetic arthroplasty is a reliable treatment option for trapeziometacarpal osteoarthritis and the CarpoFit® prosthesis has excellent long-term results for patient satisfaction, functional scores and implant survivorship.Level of evidence: III.

Postoperative Radiographic Outcomes Following Abduction-Extension Metacarpal Osteotomy: A Comparison between Early and Advanced Carpometacarpal Arthritis.

Background: This study aimed to investigate the effect of thumb metacarpal osteotomy on dorsal subluxation of the carpometacarpal (CMC) joint and compare the effects of early and advanced osteoarthritis (OA). Methods: We retrospectively reviewed 42 thumbs of 37 patients who underwent metacarpal osteotomy with a postoperative extension angle of 90° or more between January 2018 and October 2021 and were followed up for more than 2 years. The thumbs were classified into two groups: early OA (Eaton stage I or II) and advanced OA (Eaton stage III). We measured the reduction ratio, which was defined as the ratio of improvement in dorsal subluxation, at 3 months and 1 year postoperatively, and at the latest follow-up. We statistically compared the reduction ratio between the two groups and investigated the factors affecting the reduction ratio using correlation analysis. Results: The reduction ratio was significantly higher in the early OA group than in the advanced OA group at 3 months after surgery, whereas no significant difference was found between the two groups at 1 year after surgery and at the latest follow-up. A significant positive correlation was detected between the reduction ratio and the postoperative extension angle. Conclusions: First metacarpal osteotomy reduces dorsal subluxation in both early- and advanced-stage CMC OA. This procedure yields immediate marked reduction in early-stage OA, while improvement of the subluxation progressed gradually in advanced-stage OA. Level of Evidence: Level IV (Therapeutic).

Effective shape of ball-and-socket prosthesis in restoring range of thumb motion for total thumb carpometacarpal joint arthroplasty: three-dimensional motion analysis.

PURPOSE: 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. CONCLUSION: 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.

The multidirectional roles of the anterior oblique ligament and dorsoradial ligament of the thumb carpometacarpal joint.

The multidirectional biomechanics of the thumb carpometacarpal (CMC) joint underlie the remarkable power and precision of the thumb. Because of the unconfined nature of thumb CMC articulation, these biomechanics are largely dictated by ligaments, notably the anterior oblique ligament (AOL) and the dorsoradial ligament (DRL). However, the rotational and translational stabilizing roles of these ligaments remain unclear, as evidenced by the variety of interventions employed to treat altered pathological CMC biomechanics. The purpose of this study was to determine the effects of sectioning the AOL (n = 8) or DRL (n = 8) on thumb CMC joint biomechanics (rotational range-of-motion [ROM] and stiffness, translational ROM) in 26 rotational directions, including internal and external rotation, and in eight translational directions. Using a robotic musculoskeletal simulation system, the first metacarpal of each specimen (n = 16) was rotated and translated with respect to the trapezium to determine biomechanics before and after ligament sectioning. We observed the greatest increase in rotational ROM and decrease in rotational stiffness in flexion directions and internal rotation following DRL transection and in extension directions following AOL transection. The greatest increase in translational ROM was in dorsal and radial directions following DRL transection and in volar directions following AOL transection. These data suggest the AOL and DRL play complementary stabilizing roles, primarily restraining translations in the direction of and rotations away from the ligament insertion sites. These findings may inform future interventions or implant designs for pathological CMC joints.

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.

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.

Low-Level Laser Therapy for Thumb Carpometacarpal Joint Osteoarthritis: A Randomized Controlled Trial.

Background and aim Low-level laser therapy (LLLT) is considered a promising non-invasive treatment option for osteoarthritis (OA). The current study aimed to evaluate the effectiveness of LLLT on patients with OA of the first carpometacarpal joint (CMC1) of the thumb. Methods An open-level, prospective, randomized controlled trial was conducted in the Department of Physical Medicine and Rehabilitation, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, for one year. Initially, 120 patients were approached for the study. Among them, 112 eligible patients were randomly divided into two groups: the intervention group received LLLT in addition to conservative treatment, while the control group received conservative treatment alone for four weeks. Pain and functional capability (motor) improvement were assessed on a weekly follow-up basis by using various parameters such as the visual analogue scale (VAS), Ritchie articular index (tenderness scale), grip strength, key pinch strength, Dreiser functional index, and CMC1 palmer abduction. Eventually, 90 patients completed the follow-ups and were included in the analysis. Results The majority of patients diagnosed with CMC1 joint OA were in their fifties. At baseline, patients of both intervention and control groups were indifferent in terms of demography, pain intensity, motor responses, and duration of suffering. After four weeks of treatment, results indicated an overall improvement in both groups. However, the reduction of pain and increase in functional capability were not found statistically significant (p-value: ≥0.5). Conclusion LLLT with conventional treatment was not found significantly more effective enough than conventional treatment alone, but more well-designed clinical trials with larger sample sizes are needed to reach a definitive conclusion.

Isolated post-traumatic osteoarthritis of the middle carpometacarpal joint: a report of two cases.

We present two cases of isolated post-traumatic osteoarthritis in the middle carpometacarpal joint.

An Isolated Second Carpometacarpal Joint Dislocation Treated With Open Reduction and Transfixation With K-wire: A Rare Case Report.

Carpometacarpal (CMC) joint dislocation is a rare injury that can be easily missed due to non-specific clinical signs and radiologic findings. We report a patient with an isolated and irreducible dorsal dislocation of the second CMC joint, which required an open reduction and K-wire transfixation. An extensor tendon was found to be interposed between the base and the trapezoid. K-wire removal was done after three weeks and following the removal of the wire, rehabilitation was started.

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.

Trapeziectomy versus Maïa Prosthesis in Trapeziometacarpal Osteoarthritis.

Background Osteoarthritis at the base of the thumb is the most frequent osteoarthritis of the hand. Trapeziectomy in a broad variety of surgical methods have been proposed to achieve pain reduction and improvement of thumb function. A well-known disadvantage is the long recovery time. Arthroplasty of the thumb carpometacarpal joint is a competing new method for this indication with different revision and complication rates reported. Purposes The aim of this study is to assess whether there are significant differences in outcome during the first 12 months and time return to work after either, implant of a Maïa joint prosthesis, or trapeziectomy with tendon interposition after Weilby. Patients and Methods This clinical follow-up study compares the efficacy of total basal joint replacement using the Maïa prosthesis with tendon interposition arthroplasty in 59 thumbs. Clinical, functional, and radiological results at preoperative, 3-, 6-, and 12-month postoperative are presented. Results We found a significant shorter return to work in the prosthesis group with 4.5 compared with 8.6 weeks. In addition to a significant difference in pain reduction with a better Mayo wrist score in the Maïa group after 3 months. The scores are closer after 6 months and nearly match after 12 months. Measurement of the pinch grip showed a parallel course. A radiological loosening of the cup in two patients was detected after 12 months. Conclusion Implantation of Maïa prosthesis enables a significant shorter recovery but is associated with the risk of loosening and higher costs. Level of Evidence Level IV, case-control study.

Contribution of Soft Tissue Passive Forces in Thumb Carpometacarpal Joint Distraction.

Thumb carpometacarpal joint space changes when the surrounding soft tissues including the capsule, ligaments, and tendons are stretched or pulled away. When at rest, joint forces originate from passive contraction of muscles and the involvement of joint capsule and ligaments. Previous biomechanical models of hand and finger joints have mostly focused on the assessment of joint properties when muscles were active. This study aims to present an experimental-numerical biomechanical model of thumb carpometacarpal joint to explore the contribution of tendons, ligaments, and other soft tissues in the passive forces during distraction. Five fresh cadaveric specimens were tested using a distractor device to measure the applied forces upon gradual distraction of the intact joint. The subsequent step involved inserting a minuscule sensor into the joint capsule through a small incision, while preserving the integrity of tendons and ligaments, in order to accurately measure the fundamental intra-articular forces. A numerical model was also used to calculate the passive forces of tendons and ligaments. Before the separation of bones, the forces exerted by tendons and ligaments were relatively small compared to the capsule force, which accounted for approximately 92% of the total applied force. Contribution of tendons and ligaments, however, increased by further distraction. The passive force contribution by tendons at 2-mm distraction was determined less than 11%, whereas it reached up to 74% for the ligaments. The present study demonstrated that the ligament-capsule complex plays significant contribution in passive forces of thumb carpometacarpal joint during distraction.

Outcomes of Thumb Carpometacarpal Joint Osteoarthritis Treated with Arthroscopic Fusion.

Background The thumb carpometacarpal joint (CMCJ) osteoarthritis is one of the most common pathologies in the hand with controversial treatment options. Description of Technique Describe the use of arthroscopic technique for thumb CMCJ arthrodesis and the clinical outcome. Patients and Methods Cases with Eaton III thumb CMCJ osteoarthritis treated with arthroscopic arthrodesis were reviewed. Patient evaluations include: grip strength, pinch strength, range of motion, Kapandji score, Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and the visual analog scores for pain. All cases were assessed before the surgery and at 3, 6, 12, and 24 months after surgery. Radiographs were reviewed. Results There were total 16 patients with 18 arthrodesis performed. The average age was 62.2 years with M:F ratio of 2:7. The average follow-up time was 57.2 months. There was improvement of pain score as early as at postop 3 months ( p < 0.001) and continued to improve at 6, 12, and 24 months. There was improvement of grip strength and pinch strength at 12 and 24 months (p < 0.001). The DASH score showed improvement as early as at 3 months ( p = 0.012). There was a reduction of Kapandji score and interphalangeal joint motion at 3 months postop, but these returned to normal at 6 months. There was no major complication. There was one case of nonunion (5.6%). Conclusion Arthroscopic arthrodesis is a feasible treatment option and provides excellent pain relief, restore thumb strength and stability, retain functional thumb mobility, and hence improvement in hand function.

Treatment of Medial Instability of the Carpometacarpal and Tarsometatarsal Joints Using the Isolock® System in Two Dogs.

This case report describes a novel procedure using the Isolock Intrauma® implant system for treating medial instability of the carpometacarpal and tarsometatarsal joints, as demonstrated in in two dogs. A 9-year-old spayed female Spanish greyhound presented with a non-weight-bearing right hindlimb following a trauma. The clinical and radiological findings confirmed medial tarsometatarsal instability consistent with valgus deviation of the tarsus and the opening of the joint line on the medial aspect from the first to the third tarsometatarsal joints. A 4-year-old female Drahthaar presented with a non-weight-bearing left forelimb, swelling of the carpus and valgus instability. Radiological examination revealed a widening of the spaces between the intermedioradial carpal bone, second carpal bone and metacarpal bone II, confirming the medial carpometacarpal instability. In both cases, the Isolock system, an implant including ultra-high-molecular-weight polyethylene suture (UHMWPE), was used to reinforce the medial joint structures. Minor short-term complications were observed, such as swelling of the tarsal surgical site and hyperextension of the carpus, but these resolved spontaneously. No lameness or major complications were reported five months postoperatively. Carpometacarpal and tarsometatarsal instabilities are rare diseases in dogs as compared to subluxations of the other joints of the carpus and tarsus. There are no previous reports regarding the use of a UHMPWE implant for the treatment of these rare joint injuries, though the present case report suggests the validity and efficacy of the Isolock Intrauma® implant for restoring carpal and tarsal stability and preserving joint mobility.