Dorsoradial Ligament Research Articles

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.

Internal brace augmentation improves the biomechanical properties of trapeziometacarpal joint dorsoradial ligament repair

This study investigated whether dorsoradial ligament repair with internal brace augmentation provided more immediate stability in the trapeziometacarpal joint than dorsoradial ligament repair alone. Seven matched pairs of cadaveric hands were used. One specimen from each pair was assigned to the repair-only group and the other to the repair + internal brace augmentation group. Trapeziometacarpal joint range of motion and translation were quantified under different conditions for both groups: (1) intact, (2) transected dorsoradial ligament, and (3) repaired dorsoradial ligament or repaired dorsoradial ligament plus internal brace augmentation. Load-to-failure tests were performed after repair. Range of motion and translation were increased by dorsoradial ligament transection and were decreased by dorsoradial ligament repair; however, compared to the intact condition, the repair-only group demonstrated greater flexion/extension range, while the repair + internal brace group showed no significant difference in range of motion. Mean loads at 2- and 3-mm displacements were greater in the repair + internal brace group than in the repair-only group (18.0 ± 1.8 N vs. 10.8 ± 1.3 N for 2 mm displacement and 35.3 ± 3.7 N vs. 23.1 ± 2.9 N for 3 mm displacement, respectively). Internal brace augmentation improved the load-to-failure characteristics of dorsoradial ligament repair without compromising range of motion. Level of evidenceIV.

Thumb metacarpal dislocation after trapeziectomy with ligamentous reconstruction and tendon interposition: A case report

Thumb carpometacarpal (CMC) arthritis is one of the most common and debilitating pathologies evaluated by the hand surgeon, affecting up to 35% of individuals over 55 years of age. Though multifactorial in etiology, dorsal and radial subluxation of the thumb CMC due to incompetency of the volar beak ligament is thought to be among the most important factors contribution to the arthritis. Multiple operative interventions have been proposed to best address this pathology. In the United States, trapeziectomy with ligament reconstruction and tendon interposition (LRTI) as described by Burton and Pellegrini remains the most widely used technique. As an isolated trauma, dislocation of the thumb CMC joint is a rare injury, only comprising approximately 1% of injuries evaluated by hand surgeons. Typically, thumb CMC dislocations occur due to axial load with the thumb in a flexed position. They are most commonly dorsal dislocations, and are thought to occur due to failure of the dorsoradial ligament. To date, no cases of CMC dislocation after LRTI have yet been described in the literature. Here we present a patient with volar thumb CMC dislocation as a rare complication after LRTI. After percutaneous pinning and immobilization followed by hand therapy, the patient has had a successful return to work with improved pain, restored function, and no further instability.

Anatomical 3 Ligaments Reconstruction for Symptomatic Thumb Carpometacarpal Joint Instability.

Thumb carpometacarpal (CMC) joint instability is thought to be a debilitating disorder and, if left untreated, develops joint persistent synovitis and osteoarthritis. In this study, we report a novel surgical technique reconstructing the anterior oblique ligament, the dorsoradial ligament, and the intermetacarpal ligament simultaneously using both the transverse carpal ligament, and the palmaris longus tendon. Six patients with a mean age of 44 years showing no osteoarthritic changes by the radiographical examination underwent our anatomical three ligaments reconstruction for persistent painful thumb CMC joint instability. Clinical results with the mean follow-up of 20 months demonstrated that the pain was subjectively improved in all patients, both the grip and the pinch strength were increased significantly and good functional motion of the thumb could be observed after the operation. These findings indicated that our surgical procedure could be one option of treatment of the symptomatic CMC joint instability in early-stage arthritis.

Thumb Carpometacarpal joint dislocation: Case report and short review

Thumb carpometacarpal (CMC) joint dislocation is rare, and the treatment options may vary from conservatives’ strategies to open reduction and fixation. In face of pain and joint instability persistence, surgical intervention is required. We present the case of a 67-year-old male that was referred to our hospital with pain and edema of the left hand, after the failure of a conservative treatment. After initial refusal of open surgery, due to the persistent joint instability, open reduction of the CMC joint dislocation was performed, and stabilized using two percutaneous Kirschner wires after repairing the joint capsule and dorsoradial ligament. Immobilization was required for 4 weeks. After that, the Kirschner wires were removed. Along with physiotherapy, the follow-up showed no pain persistence nor CMC joint luxation reoccurrence while the joint recovered its mobility. Further studies are required in order to determine the optimal therapy for such cases and to provide standardized recommendations, taking into account that the restoration of thumb CMC joint mobility is one of the most important goals in hand surgery.

Alteration of Ligamento-Muscular Reflex Patterns After Cutaneous and Periarticular Desensitization of the Basal Thumb Joint: An Electromyographic Study

Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1 stabilizing muscles in healthy volunteers. However, it remains unclear how this ligamento-muscular reflex pattern is altered after anesthetizing sensory skin receptors and administering a further periarticular block around the CMC-1 joint, which may influence the dynamic aspects of joint stability. Ligamento-muscular reflexes were obtained from the extensor pollicis longus, abductor pollicis longus, abductor pollicis brevis, and the first dorsal interosseous muscles in 10 healthy participants after establishing superficial anesthesia of the skin around the CMC-1. The DRL was stimulated with a fine wire electrode while EMG activities were recorded during isometric tip, key, and palmar pinch. The measurements were repeated after an additional periarticular CMC-1 block using 5 ml of 1% lidocaine. Average EMG values were analyzed to compare the prestimulus and poststimulus activity. Statistically significant changes in poststimulus EMG activity were observed in all 4 muscles and all 3 tested thumb positions. A markedly reduced activity in all 4 muscles was observed in the palmar position, followed by the tip and key pinch positions. Almost no reactions were observed in the first 20 ms poststimulus for all muscles in all positions. Superficial skin anesthesia and an additional periarticular CMC-1 block anesthesia resulted in a reduced ligamento-muscular reflex pattern in all 4 muscles. Ligamento-muscular reflexes play an important role in dynamic CMC-1 joint stability. The elimination of early reactions, those considered joint-protective reflexes, is a potential risk factor for developing osteoarthritis or injury because it results in an inability to adequately protect and stabilize the joint in sudden movements.

Dorsoradial Ligament Reconstruction in Trapeziometacarpal Joint Arthritis.

The main purpose of the study is to present the alternative novel surgical technique in treating patients with trapeziometacarpal (TMC) joint arthritis using dorsoradial ligament (DRL) reconstruction technique and report the clinical outcomes. Patients who were diagnosed with TMC joint arthritis and underwent DRL reconstruction were evaluated. Visual analog pain score; Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score; grip, tip pinch, tripod pinch, and key pinch strengths along with range of motion of the thumb; and Kapandji score were recorded in the preoperative period and at follow-up. Stress examination was also performed under a fluoroscope. Eleven patients were included in the study. Median follow-up time was 13 months. At follow-up, postoperative visual analog scale and QuickDASH score improved in all patients. Grip, tip pinch, tripod pinch, and key pinch strengths also improved. The range of motion and Kapandji score were slightly improved compared with the preoperative period except for the thumb metacarpophalangeal flexion. Two patients had numbness at the thumb and spontaneously recovered after 3 months. According to recent evidence which proposed the importance of DRL in TMC joint stability, our DRL reconstruction technique may be an alternative treatment in treating patients presented with TMC joint arthritis. Further study with a longer follow-up period is needed.

Autologous chondrocyte transplantation in the treatment of thumb CMC joint osteoarthritis

Degenerative thumb carpometacarpal (CMC) joint osteoarthritis is a common disease in women starting at 40–50 years of age. Nevertheless, synovitis and initial cartilage damage start earlier, and then degenerative arthritis develops leading to joint narrowing with progressive exposure of subchondral bone, subluxation, osteophyte formation and joint deformity that can impact the surrounding joints. The aim of this study was to evaluate the outcome of patients treated with autologous chondrocyte transplantation at the thumb CMC joint at early stages. A prospective study on 10 cases of thumb CMC osteoarthritis in 8 patients was done. The thumbs were stage Eaton II (2 cases) and III (8 cases) and were treated by CMC arthroplasty with the implant of autologous chondrocytes by an open or arthroscopic technique. Two patients were treated bilaterally. Preoperatively all patients had persistent pain resistant to various kinds of nonoperative treatments for at least 1 year. Mean preoperative pinch strength was 3.7 Kg pain on VAS was 8, DASH was 55. All patients had limited abduction and flexion at the end range. Ethics committee approval was obtained for this study. Fragments of 3–4 mm of cartilage were harvested by arthroscopy or by an open technique from the wrist or elbow joint. Cartilage cells were sent to the laboratory to be grown on a collagenous biphasic matrix (MACI/Novocart®). After 3 weeks, the chondrocyte augmented scaffold was ready to be implanted in the thumb CMC joint, or frozen for a second operation later. All patients were females aged 42–67 years (mean 52 years). The dominant hand was treated in 6 cases. In 7 cases, the patients were operated with an open technique and in three cases by arthroscopy. Partial trapezium resection and dorsoradial ligament reconstruction was added to stabilize the CMC joint in most cases. Patients were seen in person at 1, 3, and 6, months, 1 year, 2 years, and 5 years after the initial surgery. Patients (nine thumbs) were then reviewed at a mean follow up 8 years (range 4.4–11 years); pain on VAS, Mayo, DASH and PRWE scores were evaluated at follow-up. One patient was lost to follow-up after 2 years. Of those nine hands, seven had an excellent result according to Mayo score, one had a good result. One thumb CMC joint was still painful and was reoperated and converted to arthroplasty after 4.4 years. All patients regained full range of motion. Mean pinch strength increased to 6.25 ± 1.3 Kg, mean DASH score was 7.3 ± 6.7; pain on VAS was 1.0 ± 1.5; these data were statistically significant compared to preoperative values (p < 0.01). Grip strength also increased in all cases, but this was not statistically significant. PRWE was 7.7 ± 6.4. No complications occurred postoperatively. The results obtained are encouraging since the implanted cartilage has lasted a mean of 8 years and up to 11 years. Biological tissue engineering techniques are being developed and could be a new solution to restore normal cartilage in young patients to postpone more aggressive surgical procedures until an older age. In cases of CMC joint instability, a ligament stabilization procedure was added to avoid subsequent damage to the implanted neocartilage. A longer follow-up and a greater number of cases are necessary to definitively establish the usefulness of this procedure, which has the advantage of being completely biological but the disadvantage of being costly.

Anatomic Reconstruction of the Anterior Oblique and the Dorsoradial Ligaments for Painful Subluxating Carpometacarpal Joint of the Thumb.

Thumb carpometacarpal osteoarthritis (CMC OA) is a common pathology of the hand that is characterized by pain, loss of grip and pinch strength, and deformity. Although conservative management is often preferred in earlier stage of CMC OA, surgical techniques can be used when symptoms are not fully relieved, especially with subluxation. We report a case series of 26 patients (32 operations) with Eaton stage I and II CMC OA who underwent a novel surgical technique that anatomically restores the CMC joint with autologous double ligament reconstruction. All cases were retrospectively reviewed as a prospective study and performed at a single regional health system from 2012 to 2016. Preoperative and postoperative radiographs, grip and pinch strength measurements, and DASH scores were collected to evaluate the outcomes. The mean CMC subluxation ratio decreased from 0.59±0.14 to 0.35±0.21 (P<0.0001). The mean grip strength increased from 44.34±17.36 pounds to 52.97±18.92 pounds (P=0.017), and the mean pinch strength increased from 10.16±4.59 pounds to 12.75±4.52 pounds (P=0.00027). The mean DASH scores decreased from 42.32±14.99 to 19.94±14.47 (P<0.0001). The average follow-up period was 39.44±14.94 months. Three patients had postoperative thumb stiffness that resolved with physical therapy. One patient had postoperative pain, attributed to carpal tunnel syndrome. One surgery required revision. All other patients (84.38%) reported significant improvement in pain and the ability to return to previous levels of work. This surgical technique is therefore a feasible option for patients with Eaton stage I or II CMC OA, and should be recommended for wider surgical use.

The Effect of the Joint Capsule and Anterior Oblique Ligament on Dorsal Subluxation of the First Metacarpal During Key Pinch.

Laxity of the anterior oblique ligament (AOL) and/or the dorsoradial ligament (DRL) are believed to contribute to the progression of osteoarthritis in the trapeziometacarpal joint through increased dorsal subluxation. Stress radiographs during functional tasks, such as key pinch, can be used to evaluate such joint instability. Cadaveric experiments can explore joint contact pressures as well as subluxation under varying conditions, to gain knowledge about joint mechanics. The disturbance of supporting tissues, such as the joint capsule, during experiments may affect the recorded stability of the joint. To evaluate potential effects of opening the joint capsule and severing the AOL, eleven cadaveric specimens were rigged to simulate key pinch. An anteroposterior (AP) radiograph of the hand was recorded for each specimen while intact, after partially opening the joint capsule and after sectioning the AOL. First metacarpal subluxation levels were compared between the intact joint, partially open joint capsule, and sectioned AOL. Neither opening the joint capsule nor cutting the AOL had a statistically significant effect on metacarpal subluxation. The results indicate that partially opening the joint capsule has a negligible effect on joint mechanics and support recent studies that postulate that the AOL plays a less substantial role in preventing subluxation.

Ligamento-Muscular Reflex Patterns Following Stimulation of a Thumb Carpometacarpal Ligament: An Electromyographic Study

The dorsoradial ligament (DRL) is essential for stability of the first carpometacarpal joint (CMC1) and is innervated with nerve endings and mechanoreceptors known to contribute to joint proprioception. The influence of these nerve endings on the neuromuscular stability of CMC1 is not yet known. This study investigated whether a ligamento-muscular reflex pathway is present between the DRL and CMC1 muscles. Ten healthy subjects (5 women and 5 men, mean age 28 years; range, 24-37 years) were included. Four primary CMC1 stabilizing muscles were investigated: the extensor pollicis longus, abductor pollicis longus (APL), abductor pollicis brevis, and first dorsal interosseous. Needle electrodes were inserted into each muscle and a fine-wire electrode was inserted into the DRL. The DRL was stimulated at 200 MHz while EMG activities in the muscles were recorded during isometric tip, key, and palmar pinch. Average EMG values were analyzed to compare prestimulus (t1) with post-stimulus (t2) activity. Poststimulus changes were observed in all 4 muscles and 3 positions tested. During tip pinch we observed mass inhibition with a decrease in all muscle amplitudes. In key pinch we observed a rapid co-contraction response. Rapid inhibitory response of antagonistic musculature was observed during palmar pinch. The APL was the only muscle to react within 20 ms after stimulation. We identified CMC1 ligamento-muscular reflexes. The mass inhibition of activity observed during tip pinch indicated a protective ligamento-muscular relation that affects all 4 muscles. The co-contractions observed promote joint stability. The fast response in the APL, coupled with its neuroanatomical proximity to the DRL, indicate a particular role in CMC1 proprioception. Proper ligamentous support and retained innervation is likely important for adequate joint function; their innate functions ought to be considered when planning surgical or orthotic treatments.

Quantitative analysis of in-vivo thumb carpometacarpal joint kinematics using four-dimensional computed tomography.

The purpose of this study was to define the normal thumb carpometacarpal joint kinematics in-vivo during opposition and abduction using four-dimensional computed-tomography in four volunteers. Movement of the metacarpal relative to the trapezium was quantified using both Euler and helical axis representations. Articular surface contact patterns were also analysed. The overall axis of rotation for the movement of opposition and abduction passes through the trapezium and the base of the proximal phalanx, respectively. An abrupt change in instantaneous axis of rotation at terminal opposition was found. Ligament modelling shows dorsoradial ligament becomes tauter towards terminal opposition, whereas anterior oblique ligament becomes more slack. These results support the existence of the 'screw-home' pivot at terminal opposition and the importance of the dorsoradial ligament for stability in this position. The normal reference set in this study can help establish a diagnostic tool for subtle carpometacarpal instability, or for evaluating efficacy of surgery.

Trapeziometacarpal stabilization through dorsoradial ligament reconstruction: An early post-surgery in vivo biomechanical analyses.

Ligament reconstruction can provide pain relief in patients with a painful, unstable, pre-arthritic trapeziometacarpal (TMC) joint. Imbrication of the dorsoradial ligament (DRL) has been proposed as a minimal invasive stabilization technique. It requires less invasive surgery than an Eaton-Littler technique and shows promising long-term clinical outcome. We used dynamic CT to objectively review the effects of the imbrication. Four patients with pain and laxity at the TMC joint, but without radiographic signs of osteoarthritis, were recruited. Dynamic CT scans were made during active thumb abduction-adduction, flexion-extension, and two functional grip tasks using a radiolucent jig. Scans of the patients were acquired before and 3 to 6 months after DRL reconstruction. Motion of each bone in the articular chain of the thumb was quantified. In addition, we mapped changes in the contact patterns between the articular facets during the entire thumb motion. After DRL imbrication, we found no overall decrease in MC1 movement in three out of four patients. Furthermore, no increase in TMC joint congruency, defined as proximity area size, was found for three out of four patients. Pre- and post-operative differences in congruency across different tasks were patient-dependent and relatively small. We demonstrated that, from a biomechanical perspective, there is high variability in post-operative outcome between patients that undergo identical surgical procedures performed by the same surgeon. A post-operative decrease in range of motion, increase in joint congruency or decrease in proximity area shift during thumb motion is not omnipresent. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2851-2864, 2018.

Modified Eaton-Littler's Reconstruction for Traumatic Thumb Carpometacarpal Joint Instability: Operative Technique and Clinical Outcomes.

Background Injuries to thumb carpometacarpal joint ligaments lead to instability. Eaton-Littler's ligament reconstruction traditionally uses a strip of flexor carpi radialis to stabilize the CMC joint. Study Description We have modified this technique to reproduce the direction of active action of the anterior oblique ligament by reconstructing both the volar and dorsoradial ligaments. In this prospective study, we evaluated patients with confirmed traumatic thumb CMC joint instability who underwent modified Eaton-Littler's reconstruction. Strength analysis, Michigan Hand Outcome Questionnaire, QuickDASH, and subjective outcome measures were collected pre- and postoperatively with minimum 3 years of follow-up. Eleven patients were included in the final analysis, with mean age of 29 years (range: 16-52) and average follow-up of 6.2 years (range: 3-11). There was a statistically significant improvement in all outcome measures. Clinical Relevance Our modified technique helps to simultaneously address both volar and dorsal ligaments and yields satisfactory clinical outcomes at medium term follow-up. Level of Evidence Level IV, case series.

Three-dimensional dynamic motion analysis of the first carpometacarpal ligaments.

The purpose of this study was to analyze the dynamic motion of the first carpometacarpal (CMC) ligaments on a three-dimensional (3-D) surface model and to examine the changes in the ligament lengths during the motion of the first CMC joint. Six fresh-frozen cadaver wrists were used to analyze the motion of the first CMC ligaments on a 3-D coordinate system using a digitizer. Four ligaments, namely, dorsoradial ligament (DRL), posterior oblique ligament (POL), superficial anterior oblique ligament (SAOL), and deep anterior oblique ligament (dAOL), were dissected and identified. Their attachments were digitized and represented on 3-D bone images. The distances between the ligament attachments of the first metacarpal and the trapezium, which were the ligament lengths, were measured during the extension-flexion and adduction-abduction of the first CMC joint. Both the DRL and POL lengthened during flexion of the first CMC joint, and both the SAOL and dAOL lengthened during extension. Both the DRL and SAOL lengthened during adduction, and both the POL and dAOL lengthened during abduction. The DRL alone lengthened significantly at flexion and adduction when the first CMC joint was in dorsoradial dislocation. The lengths of four ligaments changed significantly during first CMC joint motion. This study suggested that the DRL contributes substantial stability to the first CMC joint, preventing dorsoradial dislocation. This 3-D information improves the knowledge and understanding of the function of individual ligaments and their roles in the stability of the first CMC joint.

Efficacy of Dorsoradial Capsulodesis for Trapeziometacarpal Joint Instability: A Cadaver Study

To test the biomechanical properties of the dorsoradial capsulodesis procedure. Six cadaveric hands were used. After exposing the trapeziometacarpal (TMC) joint, we placed Kirschner wires in the distal radius and thumb metacarpal. The rotation shear test was then performed to test the joint axial laxity, and angular measurements using Kirschner wires as reference points were documented. The dorsoradial (DR) ligament and capsule were released, followed by the intermetacarpal (IM) ligament; angular measurements were obtained. Finally, the DR capsulodesis procedure was performed, and final measurements were obtained. Comparisons were made among the various stages of ligament integrity to determine the amount of stability provided by DR capsulodesis. All cadavers demonstrated axial laxity with transection of the DR ligament; an increase in stability was obtained after DR capsulodesis. Transection of the capsule and IM ligament caused increased laxity relative to the native joint (median, 24° and 35°, respectively, on rotational testing). After we performed DR capsulodesis, rotational stability improved by a median of 41° compared with DR ligament transection, 49° compared with DR and IM ligament transection, and 18° relative to the native joint. Dorsoradial capsulodesis restores rotational stability for TMC joint after division of the DR and IM ligaments. The stability achieved was statistically significant compared with both an intact native TMC joint and induced laxity of the TMC joint. The DR capsulodesis procedure may improve rotational stability to the TMC joint.

Idiopathic Trapeziometacarpal Joint Osteoarthritis: Cause, Prevention and Treatment

Background: Idiopathic osteoarthritis of the trapeziometacarpal (TMC) joint is common. Spontaneous attenuation of either the anterior oblique ligament (Beak ligament) or the dorsoradial ligament has been reported as the cause of the joint laxity, resulting in subsequent wear and tear of the articular cartilages. So far, no cause has been reported for the spontaneous attenuation of these key supporting ligaments of the TMC joint and no effective method of prevention or treatment has been reported for the early stages of the condition. Objectives: The authors reported a conservative method for the prevention as well as reversal of the early stages of the joint instability before the process of wear and tear sets in and the condition progresses towards osteoarthritis. Materials and Methods: A retrospective study was performed on 17 patients with early stages of idiopathic TMC joint osteoarthritis. The patients were treated through a conservative management protocol with an average follow-up of 28.4 months. The protocol consisted of performing specifically devised isometric exercises and a functional abduction brace. Results: The result of the conservative treatment was postural correction of the thumb, anatomical stability of the TMC joint and resolution of the symptoms as well as findings including pain, swelling and joint dorsoradial translation. The mean pain score of the patients was 3.6 before the treatment was begun and was zero after the treatment was completed. Conclusions: The presented conservative method is recommended for either prevention or reversal of the early stages of TMC joint instability before the osteoarthritic changes set in.

In vivo recruitment patterns in the anterior oblique and dorsoradial ligaments of the first carpometacarpal joint

The anterior oblique ligament (AOL) and the dorsoradial ligament (DRL) are both regarded as mechanical stabilizers of the thumb carpometacarpal (CMC) joint, which in older women is often affected by osteoarthritis. Inferences on the potential relationship of these ligaments to joint pathomechanics are based on clinical experience and studies of cadaveric tissue, but their functions has been studied sparsely in vivo. The purpose of this study was to gain insight into the functions of the AOL and DRL using in vivo joint kinematics data. The thumbs of 44 healthy subjects were imaged with a clinical computed tomography scanner in functional-task and thumb range-of-motion positions. The origins and insertion sites of the AOL and the DRL were identified on the three-dimensional bone models and each ligament was modeled as a set of three fibers whose lengths were the minimum distances between insertion sites. Ligament recruitment, which represented ligament length as a percentage of the maximum length across the scanned positions, was computed for each position and related to joint posture. Mean AOL recruitment was lower than 91% across the CMC range of motion, whereas mean DRL recruitment was generally higher than 91% in abduction and flexion. Under the assumption that ligaments do not strain by more than 10% physiologically, our findings of mean ligament recruitments across the CMC range of motion indicate that the AOL is likely slack during most physiological positions, whereas the DRL may be taut and therefore support the joint in positions of CMC joint abduction and flexion.

Primary repair of capsuloligamentous structures of trapeziometacarpal joint: A preliminary study.

Isolated trapezio-metacarpal joint dislocation is uncommon and challenging since controversy still exists regarding its management. We present a short case series in which direct repair of trapezio-metacarpal ligaments was done in three patients who had isolated, unstable dislocation of the thumb carpometacarpal joint. All of them were engaged in tasks where no compromise in hand functions and grip strength was affordable. The dislocation was addressed primarily by repair of volar oblique and dorsoradial ligaments with suture anchors. The joint was immobilised in a cast for 4 weeks followed by gradual mobilisation. At an average follow up of 15 months, all the three patients have no restriction in the range of motion. There are no symptoms and signs of instability. In two patients, there is no pain at all; while one patient has occasional pain which is mild and does not interfere with the hand function. Radiographic examination showed normal joint alignment and no signs of subluxation or early osteoarthritis. Repair of the capsuloligamentous complex with suture anchors may be considered as a treatment option in unstable trapezio-metacarpal joint dislocations in high demand patients.

Artrosis de la articulación trapecio-metacarpiana. Tratamiento quirúrgico con resección del trapecio y reconstrucción con tendosuspensión del abductor pollicis longus

Trapeziometacarpal joint osteoarthritis causes pain in the thumb, usually around the fifth decade, and with a prevalence of 25%. The deep anterior oblique ligament, the intermetacarpal ligament and the dorso-radial ligament play an important role in the stability of the joint. Materials and methodsThe results with resection of the trapezium and ligamentoplasty with abductor pollicis longus (APL) are presented in a series of cases.Two techniques were used, with one group with resection of the trapezium plus suspension arthroplasty with the APL (technique described by Brunelli), and another group with resection of the trapezium and a new suspension arthroplasty with the APL with the flexor carpi radialis. ResultsA total of 21 hands were operated on in each group, with minimum follow-up of 12 months. Pain, mobility and satisfaction were evaluated. The results were similar in both groups, with decreased pain (EVA) from between 8 and 9 to less than 1, with good mobility, and all the patients were satisfied with the results. DiscussionDifferent studies show that there are no differences between resection only of the trapezium or combined with ligament reconstruction and / or tendon interposition. The trapezoidal space decrease is almost equal in all groups, and did not correlate with the strength of the thumb.In this study, good results were achieved in both groups in terms of the reduction in pain and mobility, and similar to an earlier group treated with Artelon. These results support the hypothesis that either technique provides good results, thus we recommend using the simplest according to patient needs.