Effects of the deep anterior oblique and dorsoradial ligaments on trapeziometacarpal joint stability

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.

Synthetic Tape Augmentation for Thumb Carpometacarpal Joint Instability: Surgical Technique

Background  Dorsal thumb carpometacarpal (CMC) instability can occur after traumatic injury and can lead to persistent pain and dysfunction of the hand. We present a case report of a joint-sparing technique for recurrent thumb CMC instability after failed Eaton-Littler procedure. Case Description  We describe a technique to repair the dorsal radial ligament and augment the repair with dorsal synthetic tape. To illustrate this technique, we describe a patient who underwent the synthetic tape augmentation procedure for recurrent thumb CMC instability after a failed Eaton-Littler reconstruction. Preoperative and postoperative grip strength, appositional pinch, oppositional pinch, radial abduction, palmar abduction, and postoperative quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) were recorded. At final follow-up 18 months after surgery, the patient had returned to manual work without any functional sequelae. The thumb CMC joint was stable and his postoperative QuickDASH score was 15.9. Literature Review  Thumb CMC instability has traditionally been treated with Eaton-Littler ligament reconstruction which uses a slip of flexor carpi radialis tendon to reconstruct the deficient ligaments. More recently, the importance of the dorsal radial ligament in joint stability has been recognized and new procedures have been described to reconstruct the dorsal radial ligament. To our knowledge, synthetic tape augmentation for thumb CMC instability has not yet been described for this pathology. Clinical Relevance  Synthetic tape augmentation for dorsal thumb CMC instability may be considered in the management of dorsal thumb CMC joint instability.

The Figure-of-Eight Ligament Reconstruction in Thumb Carpometacarpal Instability: Surgical Technique and Clinical Outcomes

PURPOSE

This study reviewed the results of the figure-of-eight ligament reconstruction, a technique used in the surgical management of thumb carpometacarpal (CMC) instability. This technique establishes joint stability through forces originating within the CMC joint, providing volar and dorsal support.

METHODS

We evaluated the outcomes of 15 patients with nontraumatic, nonarthritic thumb CMC instability treated with the figure-of-eight ligament reconstruction technique. This technique involves routing a graft of the palmaris longus tendon through the base of the first metacarpal and trapezium bone in a figure-of-eight fashion. Preoperative visual analog scale (0-100) for pain and Michigan Hand Outcomes Questionnaire total scores were compared with 3- and 12-month postoperative scores. Secondary outcomes included strength, range of motion, patient satisfaction, return to work, and complications.

RESULTS

A significant improvement between intake and 12 months after surgery was observed for both Michigan Hand Outcomes Questionnaire total scores (53, SD 3 vs 70, SD 4) and visual analog scale pain scores (63, SD 4 vs 36, SD 7). Additionally, after surgery, restored thumb CMC joint stability was reported for all patients. Strength and range of motion improved between intake and 12 months after surgery. The median return to work was 6 weeks. Nine (60%) patients rated their satisfaction as "excellent" or "good," and 11 (73%) patients said that they would undergo the surgery again.

CONCLUSIONS

The figure-of-eight ligament reconstruction significantly improves pain and function in patients with thumb CMC instability while restoring joint stability and preserving range of motion, making it a suitable technique.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Trapeziometacarpal joint imaging: Normal high-resolution MRI, US and CT compared with cadaveric specimens and pathological imaging findings

INTRODUCTION

The trapeziometacarpal (TMC) joint is a complex joint, whose anatomy and function are different from the metacarpophalangeal joints of the long fingers. The stability of this joint is ensured at three levels by multiple structures: osteochondral, capsulo-ligamentous, and musculo-tendinous. The anatomical and biomechanical structures ensuring the stability of the TMC joint are perfectly evaluated on magnetic resonance imaging (MRI), with a high degree of confidence. All described ligaments are anatomically visible and perfectly assessed on MRI and ultrasound (US): the dorsoradial ligament, the posterior oblique ligament, the intermetacarpal ligament, the ulnar collateral ligament, the two bundles of the anterior oblique ligament (break ligament), as well as the superficial anterior oblique and deep anterior oblique ligaments.

METHODOLOGY

This educational review assesses the TMC joint anatomy using high-field MRI and US compared with cadaveric specimens as well the biomechanics of this joint. In addition, it highlights pathological patterns of traumatic (sprain, dislocation, and fractures) and degenerative diseases.

RESULTS AND CONCLUSION

Knowledge of TMC joint anatomy is crucial to the radiologists' understanding and assessment of various traumatic and degenerative pathologies, and thus helps clinicians and surgeons choose the appropriate treatment.

Anatomic and Biomechanical Study of Thumb Carpometacarpal Dislocations: A Laboratory Study

BACKGROUND

No previous study recreating an isolated thumb carpometacarpal (CMC) dislocation with or without suture augmentation has been performed in the laboratory. This investigation aimed to evaluate the mechanism and ligamentous complex of isolated thumb CMC dislocations.

METHODS

Biomechanical analysis was performed in 10 cadaveric specimens. A posteriorly directed force or axial loading with hyperflexion through the CMC joint was applied. Load was applied at a rate of 1 mm/s until posterior CMC dislocation was achieved. Maximum load, displacement under nominal loading, stiffness, and mode of failure were recorded. The native ligament was repaired, augmented with high-tensile suture, and testing was repeated.

RESULTS

Posteriorly directed force produced posterior CMC dislocations, while axial loading and hyperflexion through the CMC joint caused fractures. Load-to-failure of the native CMC joint was 217.76 N (SD = 66.03). Stiffness of the ligamentous complex on average was 18.86 N/mm (SD = 8.83). Mean load-to-failure after repair with suture augmentation was 94.62 N (SD = 39.77), with average stiffness of 8.21 N/mm (SD = 3.06). The native ligament was noted to have greater stiffness (P = .002) and greater load-to-failure (P = .0001) than repair with suture augmentation. Maximum displacement-to-failure of the native ligament was 14.5 mm compared with repair with suture augmentation 11.9 mm (P = .068).

CONCLUSION

Isolated CMC dislocation was achieved with a posteriorly directed force rather than hyperflexion of the joint. Ultimate failure load of the repaired ligaments with suture augmentation was about half of that of the native ligaments. Further research into this technique is warranted.

Ligament reconstruction in thumb carpometacarpal joint instability: A systematic review

In thumb carpometacarpal (CMC) instability, laxity of the ligaments surrounding the joint leads to pain and weakness in grip and pinch strength, which predisposes the patient to developing CMC joint arthritis. Recent advancements in joint anatomy and kinematics have led to the development of various surgical reconstructive procedures. This systematic review outlines the available ligament reconstruction techniques and their efficacy in treating nontraumatic and nonarthritic CMC instability. Additionally, we aimed to provide evidence which specific ligament reconstruction technique demonstrates the best results. Four databases (Embase, MEDLINE, Web of Science, and Cochrane Central) were searched for studies that reported on surgical techniques and their clinical outcomes in patients with nontraumatic and nonarthritic CMC instability. Twelve studies were analyzed for qualitative review, including nine different surgical ligament reconstruction techniques involving two hundred and thirty thumbs. All but one of the reported techniques improved postoperative pain scores and showed substantial improvement in pinch and grip strength. Complication rates varied between 0% and 25%. The included studies showed that ligament reconstruction effectively alleviated the patients' complaints regarding pain and instability, resulting in overall high patient satisfaction. Nevertheless, drawing definitive conclusions regarding the superiority of any ligament reconstruction technique remains challenging owing to the limited availability of homogeneous data in the current literature.

Dorsoradial Ligament Reconstruction in Trapeziometacarpal Joint Arthritis

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Outcomes of First Metacarpal Extension Osteotomy for Base of Thumb Arthritis

BACKGROUND

First metacarpal extension osteotomy (FMEO) aims to correct the adduction deformity associated with thumb arthritis, as well as improve the congruity at the first carpometacarpal (FCMC) joint. However, the benefits of this procedure are currently unclear. The purpose of this study is to investigate the outcomes of FMEO in the treatment of FCMC joint arthritis.

METHODS

Electronic databases were searched systematically for original data studies in the English language reporting outcomes following FMEO for base of thumb arthritis. Data were extracted from the text, tables, and figures of publications and meta-analyzed where possible.

RESULTS

Ten publications comprising 211 thumbs were included. FMEO was associated with an improvement in pain relief and patient-reported functional outcomes, however meta-analysis showed no significant long-term improvement in grip strength or lateral pinch grip. Although there was disease progression in one third of patients after FMEO, most did not require further procedures. Outcomes following secondary procedures was not analyzed in the literature. FMEO produced a range of minor complications, however, major complications were rare.

CONCLUSIONS

The available evidence suggests FMEO does not improve grip or pinch strength. However, it may have a role in analgesia and improvement in functional outcomes. Further studies should compare outcomes of FMEO to continued nonoperative treatment, or other surgical options including arthroscopy or ligamentous reconstruction.

Systematic Review of Ligament Reconstruction of Traumatic Isolated Thumb Carpometacarpal Joint Dislocation

INTRODUCTION

Thumb carpometacarpal (CMC) joint dislocations are rare with minimal agreement on surgical management. The dorsoradial ligament (DRL) is the primary joint stabilizer but has not historically been reconstructed. We hypothesize that the reported reconstruction of first CMC joint dislocations primarily uses the flexor carpi radialis (FCR) without collective agreement on a surgical technique.

METHODS

A systematic review of the PubMed database from 1996 to 2022 was done. Keywords were "thumb dislocation," "thumb carpometacarpal dislocation," and "carpometacarpal joint ligament repair." Inclusion criteria included isolated, unstable thumb CMC dislocations with reconstruction. The Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines were used.

RESULTS

Four hundred thirty-seven records were identified, and nine met inclusion criteria. Two articles were cohort studies, and seven were case reports. Thirty-seven patients were included, and 26 patients had reconstruction with tendonous autograft. Twenty-five (96.2%) used the FCR and 1 (3.9%) from the palmaris longus. Three patients had reconstruction with a suture anchor. Surgical techniques varied between studies.

DISCUSSION

The recommendation of the authors recreates the DRL during autograft repair. Current repair techniques that recreate the DRL use the FCR, but quantitative comparisons of tendonous autografts or suture anchors have not been done.

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.

Anatomy and Biomechanics of the Thumb Carpometacarpal Joint

This review discusses the anatomy and biomechanics of the thumb carpometacarpal (CMC) joint. This articulation between the trapezium and first metacarpal is integral for opposition and other complex movements necessary for pinch and grasp maneuvers. Fortunately, this joint is well equipped to handle the extreme forces imposed by these movements, as it is stabilized by an elaborate arrangement of ligaments and muscles. Without this stability, thumb subluxation would occur with loading during pinch and grasp, and human prehension would be impossible. Understanding the interactions occurring within this joint is essential for adequately treating pathology arising in this crucial joint.

Ligamentous constraint of the first carpometacarpal joint

To examine the role of the ligaments in maintaining stability of the first carpometacarpal (CMC) joint, a sequential ligament sectioning study of sixteen specimens was performed. While a small compressive force was maintained, loads were applied to displace each specimen in four directions - volar, dorsal, radial, and ulnar. Translations of the specimen in both dorsal-volar and radial-ulnar axes were measured. Initially, the tests were conducted with the specimen intact. These tests were then repeated following sectioning of the CMC anterior oblique ligament (AOL), ulnar collateral ligament (UCL), intermetacarpal ligament (IML) and dorsal radial ligament (DRL). The first CMC joint translation was increased in the absence of IML and DRL (p < 0.05). Both IML and DRL were important in constraining the first CMC joint translation against external applied loads. Potential applications of these findings include the treatment of joint hypermobility and the reduction or delay of onset or progression of first CMC joint osteoarthritis.

Basal joint arthroscopy indications in first CMC joint arthritis

Basal joint arthroscopy is one of the more recent evolutions of small joint arthroscopy in upper limb surgery. Conventional arthroscopy equipment is generally sufficient to perform these procedures without any specific adaptation. Arthroscopic exploration of the trapeziometacarpal joint is performed through 1R, 1U portals with the addition of a thenar portal in some indications. In the context of basal joint arthritis, we can distinguish diagnostic, preventive and therapeutic indications for arthroscopy. Diagnostic indications are the assessment of painful post-traumatic basal joint lesions of cartilage and ligaments, and the evaluation of chondromalacia and ligament attenuation to help classify basal joint osteoarthritis to provide additional clinical information, which can influence further treatment depending on the stage of the disease. Preventive indications are reduction of Bennett's fracture, basal joint dislocation management to avoid post-traumatic instability and chondromalacia; it can also be indicated after decompensation of hyperlaxity. Therapeutic indications are debridement, ligament augmentation procedures or shrinkage ± interposition ± partial or total trapeziectomy, ligamentoplasty, etc. Basal joint arthroscopy appears to be the seat of advances in arthroscopic procedures with clinical results at least as effective as classical open surgery, but this technique still requires long-term evaluation.

Anatomy and biomechanics of healthy and arthritic trapeziometacarpal joints

Understanding the biomechanics of the trapeziometacarpal (TMC) or first carpometacarpal (CMC1) joint, the pathophysiology of basal thumb arthritis, the design and performance of surgical procedures require a solid anatomical basis. This review of literature summarizes the most recent data on the descriptive, functional, and comparative anatomy of healthy and arthritic TMC joints.

Management of thumb carpometacarpal joint dislocations: A systematic review

Although rare, thumb Carpometacarpal (CMC) joint dislocations can have significant complications which impact hand function. Optimal management is crucial in restoring pinch and grasp strength, but no agreement exists regarding treatment due to a paucity of literature on this subject. Systematic review was conducted involving non-operative and operative management of the CMC joint. 15 articles with a total of 60 thumbs were evaluated from published literature. 12/60 thumbs with isolated CMC joint dislocations were treated with closed reduction, with 4 cases needing additional ligament repair due to joint instability post-reduction. 51/60 of the isolated CMC joint dislocations had ligament reconstruction, with flexor carpi radialis tendon autograft (29/51) as the most popular option. 60/60 patients regained full function and stability of the CMC joint with significant pain relief. Although good surgical outcomes have been achieved, long term clinical outcome reporting is needed to develop a standardized approach to treatment.

Snapping Extensor Pollicis Longus Tendon Subluxation Secondary to Trapeziometacarpal Instability: Case Report and Technique

CASE

A 20-year-old woman presented with painful, snapping extensor pollicis longus (EPL) tendon subluxation and trapeziometacarpal (TMC) joint instability. Hemi-extensor carpi radialis longus (ECRL) tendon autograft stabilized the TMC joint, reconstructing the 1-2 intermetacarpal ligament. The subluxed EPL tendon was centralized over the dorsal first metacarpal by tightening the metacarpophalangeal radial sagittal band and creating a dorsal first metacarpal "neosheath" pulley using ECRL graft remnant. Postoperative rehabilitation included Spica bracing and immediate thumb interphalangeal joint exercises.

CONCLUSION

The patient's pain due to EPL tendon subluxation and TMC joint instability completely resolved. Postoperative thumb range of motion and function were equivalent to the nonaffected side.

First Carpometacarpal Joint Instability: Dorsal Ligament Reconstruction

The first carpometacarpal (CMC-I) joint has an elaborate ligamentous support. Recent evidence has demonstrated that the dorsal ligament group is imperative for joint stability and that CMC-I joint instability may occur as a consequence of trauma and ligamentous laxity, and other conditions, with possible CMC-I subluxation and the development of osteoarthritis. Although various surgical techniques have been introduced for the treatment of ligamentous CMC-I instability, the Eaton-Littler reconstruction has been regarded as the gold standard. It is widely accepted that impaired hand function may still be present following the reconstruction of the CMC-I joint ligaments, demonstrating the existing limitations of current surgical techniques. In this paper, a novel extra-articular technique relating to CMC-I joint instability and focusing on the dorsal ligament group is described. A graft taken from the abductor pollicis longus tendon is utilized to reconstruct the dorsal radial ligament and posterior oblique ligament. This technique may provide a less invasive alternative than the gold standard procedure and the hypothesis is that it will lead to a better outcome.

Prevalence and distribution of MRI abnormalities in the articular cartilage and supporting ligaments in patients with early clinical stage first carpometacarpal joint osteoarthritis

OBJECTIVE

We used magnetic resonance imaging (MRI) to evaluate where articular degeneration begins and which ligaments are most often involved in the early clinical stage first carpometacarpal joint (CMCJ-1) osteoarthritis.

MATERIALS AND METHODS

We retrospectively analyzed the MRI findings of 26 patients with early clinical stage CMCJ-1 osteoarthritis and no radiologic abnormalities and 19 control patients without CMCJ-1 pain or osteoarthritis who underwent MRI for dorsal or ulnar wrist pain. Two observers blinded to group and clinical findings independently assessed the presence of chondral defects in four quadrants of the CMCJ-1: volar-ulnar (VU), volar-radial (VR), dorso-ulnar (DU), and dorso-radial (DR). The integrity of the four major ligaments of the CMCJ-1, i.e., the anterior oblique ligament (AOL), the intermetacarpal ligament (IML), the posterior oblique ligament (POL), and the dorsal radial ligament (DRL), was assessed. The observer reliability was analyzed using Cohen's kappa coefficient. The prevalence of cartilage lesions and ligament abnormalities in the osteoarthritic and control patients was compared using Fisher's exact test.

RESULTS

Cartilage lesions were significantly more common in the VU quadrant of the trapezium in the osteoarthritic patients than in the control patients (17/26 vs. 2/19; P = 0.002). AOL abnormalities were more common in the osteoarthritic patients than in the control patients (14/26 vs. 3/19; P = 0.009).

CONCLUSION

The MRI findings of early clinical stage CMCJ-1 osteoarthritis commonly demonstrated cartilage lesions in the VU quadrant of the trapezium and ligament abnormalities in the AOL.

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.

Clinical practice algorithm for Eaton's injury of the thumb

Trapeziometacarpal joint instability is a well-recognised but under-diagnosed cause of basal thumb pain. A systematic approach with sound understanding of anatomy and clinico-pathological correlation is required to make a diagnosis. We discuss an overview of the principles of diagnosis and management of basal thumb joint instability. An evaluation algorithm for Eaton's injury of the thumb is proposed for clinical application with evidence in literature.

[Basal joint osteoarthritis of the thumb]

The basal joint of the thumb (articulatio carpometacarpalis pollicis) is the joint of the hand most frequently affected by arthritis. Arthritis of the basal joint of the thumb typically occurs in the second half of life and more frequently in women. The clinical symptoms are pain, joint swelling, reduced strength and limited hand function with a reduced hand span. When clinical symptoms first appear a conservative treatment is initially indicated. If these measures do not lead to an improvement of the complaints, various operative measures are possible depending on the stage of the disease detected by radiological imaging.

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.

An anatomical study on the effectiveness of Arthrex Mini TightRope® ligament reconstruction in an unstable trapeziometacarpal joint

INTRODUCTION

Laxity in the trapeziometacarpal (TMC) joint is a debilitating condition usually affecting a young population. It can be treated operatively with ligament reconstruction. The purpose of this study was to determine the effectiveness of the Arthrex Mini TightRope^® in reinforcing the stabilizing ligaments in an unstable TMC joint without decreasing the range of motion of the thumb. This method was compared with the "gold standard" published by Eaton and Littler in 1973.

MATERIALS AND METHODS

Six fresh frozen arms from five cadavers were included. TMC joint laxity was measured on stress view radiographs as the ratio of the radial subluxation (RS) of the first metacarpal in relation to the trapezium, by the first metacarpal articular width (AW) (as described by Wolf in 2009). Measurements of the pre- and post-operative range of motion (ROM) were performed and compared.

RESULTS

Both the Arthrex Mini TightRope^® and the Eaton-Littler stabilization improved the stability of the TMC joint. The pre-operative laxity value (ratio RS/AW) of 0.27 was significantly (P = 0.02) improved by each of the surgical interventions (Eaton-Littler RS/AW = 0.05 and Tightrope RS/AW = 0.09). The pre- and post-operative range of motion was not significantly different by each of the surgical interventions. There were no significant differences between the two stabilizing methods regarding laxity or range of motion.

CONCLUSION

The Arthrex Mini TightRope^® provided a good stabilization method for the TMC joint in this anatomical model without compromising the range of motion.

Sick Leave After Surgery for Thumb Carpometacarpal Osteoarthritis: A Population-Based Study

PURPOSE

Patients undergoing surgery for thumb carpometacarpal (CMC1) osteoarthritis often require sick leave owing to postoperative immobilization, pain, and decreased function. Our goal was to evaluate the amount of sick leave after surgery for 2 common CMC1 arthroplasty procedures.

METHODS

Using registry data from the Skåne region of southern Sweden, cross-linked with employment data showing person-specific sick leave, 2 cohorts of CMC1 surgical patients, between ages 40 and 59 years, were examined. These comprised all persons undergoing soft tissue arthroplasty and prosthetic implant arthroplasty from 2004 to 2012 identified using International Classification of Diseases, 10th Revision, and surgical codes. These subjects were analyzed against an age- and sex-matched reference population cohort.

RESULTS

Surgical cohorts of 326 and 169 subjects undergoing soft tissue and prosthetic CMC1 arthroplasty, respectively, were compared with reference populations of 1,110 and 574 persons. Surgical subjects had a pronounced increase in sick leave in the first 2 months after surgery, followed by diminishing days of leave over time. Mean sick leave time after soft tissue arthroplasty was 202 days in women and 170 days in men. Following prosthetic arthroplasty, mean sick leave was 177 days in women and 188 in men. When we excluded those with documented sick leave in the month before surgery (owing to preoperative CMC1 disability or other medical issues), the mean postoperative sick leave decreased to 137 days in women and 125 days in men after soft tissue arthroplasty compared with 109 and 94 days in women and men after prosthetic implant arthroplasty, and this difference was significant. There were no differences in the length of sick leave between sexes and no correlation with age.

CONCLUSIONS

Soft tissue arthroplasty and implant arthroplasty for patients with CMC1 osteoarthritis are both associated with substantial sick leave time, indicating the impact of surgery on return to work. There were no differences in sick leave by sex or age.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

In Vivo 3-Dimensional Kinematics of Thumb Carpometacarpal Joint During Thumb Opposition

PURPOSE

This study primarily aimed to demonstrate the screw-home rotation of the thumb carpometacarpal (CMC) joint and the function of surrounding ligaments during thumb oppositional motion.

METHODS

A 3-dimensional kinematic analysis of the thumb CMC joint was conducted using data derived from computed tomography of 9 healthy volunteers. Scans were obtained in the neutral forearm and wrist position and the thumb in maximum radial abduction, maximum palmar abduction, and maximum opposition. The movements of the first metacarpal and the palmar and dorsal bases on the trapezium during thumb oppositional motion from radial abduction through palmar abduction were quantified using a coordinate system originating on the trapezium. In addition to the kinematic analyses, the length of virtual ligaments, including the anterior oblique, ulnar collateral, dorsal radial, dorsal central (DCL), and posterior oblique ligament (POL), were calculated at each thumb position.

RESULTS

From radial abduction to opposition of the thumb through palmar abduction, the first metacarpal was abducted, internally rotated, and flexed on the trapezium. The palmar base of the first metacarpal moved in the palmar-ulnar direction, and the dorsal base moved in the palmar-distal direction along the concave surface of the trapezium. Although the DCL and POL lengthened, the lengths of other ligaments did not change significantly.

CONCLUSIONS

During thumb oppositional motion, internal rotation of the first metacarpal occurred, with the palmar base rotating primarily with respect to the dorsal base. The DCL and POL may be strained in thumb functional positions.

CLINICAL RELEVANCE

Kinematic variables indicated a screw-home rotation of the thumb CMC joint and the contribution of the dorsal ligaments to the stability of the rotation on the pivot point.

Assessment of normal trapeziometacarpal joint alignment

The purpose of this study was to determine the alignment of the normal trapeziometacarpal joint and any changes in its alignment with age. Radial, dorsal and dorsoradial subluxation were measured on computerized tomographic scans in 50 joints of 50 adults aged 18 to 62. There were statistically significant correlations between increasing age and dorsoradial subluxation but no significant correlation with dorsal and radial subluxation. Significant dorsoradial subluxation occurs after 46 years of age in the normal trapeziometacarpal joint. A mean dorsoradial subluxation of 21% (range 14%-30%) can be considered normal in this age group.

Thumb Injuries in Athletes

Thumb injuries are common in athletes and present a challenging opportunity for upper extremity physicians. Common injuries include metacarpal base fractures (Bennett and Rolando types), ulnar and radial collateral ligament injuries, dislocation of the carpometacarpal and metacarpophalangeal joints, and phalanx fractures. This review, although not exhaustive, highlights some of the most common thumb injuries in athletes. The treating physician must balance pressure from athletes, parents, coaches, and executives to expedite return to play with the long-term well-being of the athlete. Operative treatment may expedite return to play; however, one must carefully weigh the added risks involved with surgical intervention.

Three-dimensional dynamic motion analysis of the first carpometacarpal ligaments

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Surgical stabilization for symptomatic carpometacarpal hypermobility; a randomized comparison of a dorsal and a volar technique and a cohort of the volar technique

BACKGROUND

Hypermobility of the first carpometacarpal joint is mostly surgically treated with a volar approached stabilization by Eaton, but recent studies indicate the importance of the dorsoradial and intermetacarpal ligaments (DRL and IML) for carpometacarpal joint stability. The aim of this study was to compare a dorsal and volar technique for primary carpometacarpal hypermobility regarding pain and functional outcome.

METHODS

Patients with non-degenerative, painful carpometacarpal hypermobility were included and were randomly assigned to either the volar technique using the FCR, or a dorsal technique using the ECRL. After premature termination of the trial, we followed all patients treated with the volar approach. Pain, strength, and ADL function using DASH and Michigan Hand Questionnaires (MHQ) were measured at baseline and 3 and 12 months after surgery.

RESULTS

After including 16 patients, the randomized trial comparing the volar and dorsal technique was terminated because of significant increased pain in the dorsal group. Although none of the other outcome measures were significant in the underpowered comparison, in line with the pain scores, all variables showed a trend towards a worse outcome in the dorsal group. Between 2009 and 2012, 57 thumbs were surgically stabilized. We found significant better pain and MHQ scores, and after 1 year improved grip and key pinch strength. Patients returned to work within 8 (±7) weeks, of which 85 % in their original job.

CONCLUSIONS

Surgical stabilization of the thumb is an effective method for patients suffering from hypermobility regarding pain, daily function, and strength. We recommend a volar approach. Level of Evidence: Level I, therapeutic study.

Ligamentous Reconstruction of Traumatic Dislocation of Thumb Carpometacarpal Joint: Case Report and Review of Literature

Introduction:

Thumb carpometacarpal dislocation is a rare injury with many treatment options described in literature.

Case Description:

A 47-year-old male patient presented to hospital with an isolated dorsal dislocation of the thumb carpometacarpal joint. Closed reduction of the dislocation could be easily done but joint was grossly unstable and redislocated. Repair of ruptured dorsoradial ligament and joint capsule was done with immobilization for 6 weeks. At 2-years follow-up evaluation, the patient was pain free and returned to his previous level of activity. No restriction of carpometacarpal movements or residual instability was noticed. Radiographic examination showed normal joint congruity and no signs of osteoarthritis.

Conclusion:

Capsuloligamentous repair can be considered the treatment of choice in thumb carpometacarpal dislocations with instability after closed reduction.

Altered Innervation Pattern in Ligaments of Patients with Basal Thumb Arthritis

Purpose The population of mechanoreceptors in patients with osteoarthritis (OA) lacks detailed characterization. In this study, we examined the distribution and type of mechanoreceptors of two principal ligaments in surgical subjects with OA of the first carpometacarpal joint (CMC1). Methods We harvested two ligaments from the CMC1 of eleven subjects undergoing complete trapeziectomy and suspension arthroplasty: the anterior oblique (AOL) and dorsal radial ligament (DRL). Ligaments were divided into proximal and distal portions, paraffin-sectioned, and analyzed using immunoflourescent triple staining microscopy. We performed statistical analyses using the Wilcoxon Rank Sum test and ANOVA with post-hoc Bonferroni and Tamhane adjustments. Results The most prevalent nerve endings in the AOL and DRL of subjects with OA were unclassifiable mechanoreceptors, which do not currently fit into a defined morphological scheme. These were found in 11/11 (100%) DRLs and 7/11 (63.6%) AOLs. No significant difference existed with respect to location within the ligament (proximal versus distal) of mechanoreceptors in OA subjects. Conclusion The distribution and type of mechanoreceptors in cadavers with no to mild OA differ from those in surgical patients with OA. Where Ruffini endings predominate in cadavers with no to mild OA, unclassifiable corpuscles predominate in surgical patients with OA. These findings suggest an alteration of the mechanoreceptor population and distribution that accompanies the development of OA. Clinical Relevance Identification of a unique type and distribution of mechanoreceptors in the CMC1 of symptomatic subjects provides preliminary evidence of altered proprioception in OA.

Usefulness and complications associated with thenar and standard portals during arthroscopic surgery of thumb carpometacarpal joint

PURPOSE

Advances in small arthroscopy have enabled a minimally invasive surgery for thumb carpometacarpal joints. However, surgery is often difficult using standard CM-radial (CM-R) and CM-ulnar portals (CM-U). Here, we describe the clinical applications and complications associated with using thenar portal (TP) and standard portals.

METHODS

Arthroscopic surgeries of thumb carpometacarpal joint were performed in 21 patients including 15 patients with osteoarthritis and six Bennett's fracture-dislocations. Complications and the frequency of use associated with each portal were evaluated.

RESULTS

Complications associated with the CM-R portal comprised paresthesia due to damage of the radial nerve branches in two patients. No nerves were damaged but the operation scar became tender at the TP in three patients. The CM-R was used at a lower frequency when the TP was utilized.

CONCLUSION

The clinical use of TP may decrease the risk of radial sensory nerve damage through decreasing frequency of use of the CM-R that is located near the nerve.

LEVEL OF STUDY

IV.

Current review of trapeziometacarpal osteoarthritis (rhizarthrosis)

Trapeziometacarpal (TMC) joint is the secondly affected joint for osteoarthritis in the hand. TMC joint arthritis affects most commonly postmenopausal women after the fifth decade of life, due to hormonal and structural factors. Rhizarthrosis may lead to a clinical spectrum from subtle symptoms to advanced symptoms such as; severe pain, limitation of range of motion, muscular weakness, bony deformities, and end up ultimately with disability. Regardless of the etiopathogenesis; a variety of non-surgical and surgical methods have been used for the treatment of rhizarthrosis, depending on the age of the patient, symptomatology and the stage of the disease. The main goals of the treatments are as follows; relief of pain, conservation or restoration the stability and mobility of the TMC joint with the optimal preservation of the strength of surrounding musculature. In this article, the current methods, which have been used for the treatment of TMC joint osteoarthritis, will be mainly reviewed, together with concise up-to-date information on both its diagnosis and the anatomy of the TMC joint.

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.

Imaging and management of thumb carpometacarpal joint osteoarthritis

Primary osteoarthritis (OA) involving the thumb carpometacarpal (CMC) joint is a common and frequently debilitating disease. Clinical examination and radiographs are usually sufficient for diagnosis; however, familiarity with the cross-sectional anatomy is useful for diagnosis of this condition. The most widely used classification system for the radiographic staging of thumb carpometacarpal joint OA was first presented by Eaton and Littler, ranging from mild (stages I and II) to severe (stage IV) disease. If conservative treatment fails, surgical treatment is considered. A variety of surgical techniques have been developed and implemented for the management of this pervasive and disabling condition. The purpose of this article is to review the anatomy of the basal joints of the thumb, pathophysiology, preoperative imaging, and various surgical techniques that are utilized in the treatment of OA of the basal joints of the thumb with emphasis on normal postoperative radiographic findings and possible postoperative complications.

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

BACKGROUND

Isolated trapezio-metacarpal joint dislocation is uncommon and challenging since controversy still exists regarding its management.

DESCRIPTION

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.

RESULTS

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.

CONCLUSION

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.

Detection of relaxin receptor in the dorsoradial ligament, synovium, and articular cartilage of the trapeziometacarpal joint

Basilar thumb osteoarthritis (OA) is postulated to occur due to ligament attenuation of the trapeziometacarpal (TM) joint. Relaxin is a peptide hormone, which loosens ligaments before childbirth, through remodeling of the extracellular matrix via upregulation of matrix metalloproteases (MMPs). We postulated that relaxin family peptide receptor 1 (RXFP-1), the receptor for circulating relaxin, was present in tissues of the TM joint. Ligaments and synovium were sampled from 15 patients during surgery for TM arthritis. We obtained trapezial cartilage from two autopsy donors and four patients. Tissues were fixed, paraffin embedded, and sectioned at 5 µm, then were immunostained for RXFP-1, as well as MMP-1, and MMP-13, using rabbit anti-human polyclonal antibodies. Eight DRL samples showed positive immunostaining for relaxin receptor, with 14/15 positively stained in synovium. Greater staining was seen in specimens obtained from women with more severe TM arthritis. Trapezial cartilage demonstrated receptor staining within chondrocytes in the middle and deep zones. Immunostaining for MMPs co-localized with relaxin receptor staining. Relaxin receptors are present at the ligament, cartilage, and synovium of the TM joint, indicating that it is a potential target for relaxin. This suggests that circulating relaxin may impact joint stability. The role of relaxin in cartilage and synovium may be related to its role in collagen regulation as a possible tissue response to OA.

Comparison of the anatomical dimensions and mechanical properties of the dorsoradial and anterior oblique ligaments of the trapeziometacarpal joint

PURPOSE

The respective roles of the dorsoradial (DRL) and anterior oblique (AOL) ligaments in stability of the highly mobile trapeziometacarpal (TMC) joint remain disputed. Earlier publications have pointed to the AOL as the key stabilizing structure; yet, more recent publications have challenged the stabilizing role of the AOL, favoring the DRL as the main TMC joint stabilizer. We executed an anatomical study of the ligaments, including detailed dissection to quantify the length, width, and thickness of the AOL and DRL and tested the material properties of these ligaments.

METHODS

Thirteen fresh frozen cadaveric thumbs from 9 specimens were used. Length, width, and thickness of the AOL and DRL were measured on magnetic resonance imaging and/or after dissection. Next, the first metacarpal and trapezium were isolated together with both ligaments, and both bones were cut sagittally to isolate a first metacarpal-AOL-trapezium and first metacarpal-DRL-trapezium complex from each thumb. These samples were subjected to cyclic loading in displacement-controlled tests. The obtained force-displacement curves were used to calculate stiffness and hysteresis of each sample.

RESULTS

Our results showed that the DRL is significantly shorter and thicker than the AOL, which is thin and ill-defined. Our results also indicate that the DRL has a higher stiffness than the AOL, making it a more likely candidate to provide joint stability.

CONCLUSIONS

Although the AOL has been asserted to be the primary restraint to dorsoradial subluxation, this view has been challenged over the past 10 years by several studies. These studies have shown the AOL to be relatively weak and compliant compared with the intermetacarpal and dorsoradial ligaments and have demonstrated that the DRL is the strongest and stiffest ligament of the TMC joint. Our studies confirm these findings.

CLINICAL RELEVANCE

This study indicates that the DRL is relatively stiff and thick, suggesting it should be repaired or reconstructed when disrupted to restore stability of the TMC joint.

Relationship of relaxin hormone and thumb carpometacarpal joint arthritis

BACKGROUND

The female predominance in thumb carpometacarpal (CMC) joint arthritis has led to speculation that reproductive hormones or hypermobility are responsible. Evidence shows that patients with pathologic laxity have a higher rate of thumb CMC arthritis. Relaxin hormone increases laxity in the pelvic ligaments through upregulation of matrix metalloproteases (MMPs). It is thus a hormone of interest in the development of thumb CMC arthritis.

QUESTIONS/PURPOSES

Our goals were to identify demographic and hormonal factors associated with joint laxity in patients with CMC arthritis and to evaluate the relationship among serum relaxin, relaxin receptors, and MMPs in the anterior oblique ligament (AOL) of the thumb. We hypothesized that serum relaxin was correlated with joint laxity as well as with relaxin receptors and MMPs in the AOL.

METHODS

Forty-nine patients undergoing thumb CMC arthroplasty underwent laxity examination, blood draw, and AOL sampling. Ligaments were analyzed for relaxin receptor and MMPs 1 and 3 using quantitative reverse-transcriptase polymerase chain reaction.

RESULTS

Women demonstrated more joint laxity than men (p < 0.001). RNA analysis confirmed relaxin receptors in the AOL as well as MMPs 1 and 3. There was a significant correlation between serum relaxin and MMP-1 (p = 0.04). Detectable serum relaxin was negatively correlated with relaxin receptors in the AOL (p = 0.02).

CONCLUSIONS

Further studies are needed to evaluate the role of laxity and sex hormones in thumb CMC arthritis.

CLINICAL RELEVANCE

Relaxin hormone may play a role in the development of arthritis at the thumb CMC joint.

LEVEL OF EVIDENCE

Level I, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Trapeziometacarpal joint stability: the evolving importance of the dorsal ligaments

BACKGROUND

Trapeziometacarpal (TMC) arthritis of the thumb is a common source of hand pain and disability. TMC ligamentous instability may play a role in TMC degeneration. However, the relative importance of the TMC ligaments in the etiology of degeneration and the use of surgery to treat instability in early-stage arthritis are unclear.

QUESTIONS/PURPOSES

In this review, we addressed several questions: (1) What are the primary ligamentous stabilizers of the thumb TMC joint? (2) What is the evidence for ligament reconstruction or ligament imbrication in the treatment of thumb TMC joint osteoarthritis? And (3) what is the evidence for thumb metacarpal osteotomy in the treatment of thumb TMC joint osteoarthritis?

METHODS

We performed a systematic review of the literature using PubMed (MEDLINE(®)) and Scopus(®) (EMBASE(®)) for peer-reviewed articles published until November 2012. Fifty-two studies fit the inclusion criteria. Twenty-four studies were anatomic, biomechanical, or histopathologic studies on TMC joint ligamentous anatomy, 16 studies were clinical studies concerning ligament reconstruction, and 12 studies were clinical studies on thumb metacarpal osteotomy.

RESULTS

Over the past two decades, increasing evidence suggests the dorsoradial ligament is the most important stabilizer of the TMC joint. Other ligaments consistently identified are the superficial anterior oblique, deep anterior oblique, intermetacarpal, ulnar collateral, and posterior oblique ligaments. Ligament reconstruction and metacarpal osteotomy relieve pain and improve grip strength based on Level IV studies.

CONCLUSIONS

The dorsal ligaments are the primary stabilizers of the TMC joint. Ligament reconstruction and metacarpal osteotomy ameliorate ligamentous laxity and relieve pain based on Level IV studies.

Ultrastructure and innervation of thumb carpometacarpal ligaments in surgical patients with osteoarthritis

BACKGROUND

The complex configuration of the thumb carpometacarpal (CMC-1) joint relies on musculotendinous and ligamentous support for precise circumduction. Ligament innervation contributes to joint stability and proprioception. Evidence suggests abnormal ligament innervation is associated with osteoarthritis (OA) in large joints; however, little is known about CMC-1 ligament innervation characteristics in patients with OA. We studied the dorsal radial ligament (DRL) and the anterior oblique ligament (AOL), ligaments with a reported divergent presence of mechanoreceptors in nonosteoarthritic joints.

QUESTIONS/PURPOSES

This study's purposes were (1) to examine the ultrastructural architecture of CMC-1 ligaments in surgical patients with OA; (2) to describe innervation, specifically looking at mechanoreceptors, of these ligaments using immunohistochemical techniques and compare the AOL and DRL in terms of innervation; and (3) to determine whether there is a correlation between age and mechanoreceptor density.

METHODS

The AOL and DRL were harvested from 11 patients with OA during trapeziectomy (10 women, one man; mean age, 67 years). The 22 ligaments were sectioned in paraffin and analyzed using immunoflourescent triple staining microscopy.

RESULTS

In contrast to the organized collagen bundles of the DRL, the AOL appeared to be composed of disorganized connective tissue with few collagen fibers and little innervation. Mechanoreceptors were identified in CMC-1 ligaments of all patients with OA. The DRL was significantly more innervated than the AOL. There was no significant correlation between innervation of the DRL and AOL and patient age.

CONCLUSIONS

The dense collagen structure and rich innervation of the DRL in patients with OA suggest that the DRL has an important proprioceptive and stabilizing role.

CLINICAL RELEVANCE

Ligament innervation may correlate with proprioceptive and neuromuscular changes in OA pathophysiology and consequently support further investigation of innervation in disease prevention and treatment strategies.

Functional patterns of thumb key pinch and their influence on thumb strength and stability

Introduction

Trapeziometacarpal osteoarthritis (TMC OA) is a common condition frequently related to instability and hypermobility. Many factors are involved in the development of this degenerative process. Recent research suggests that the position of the metacarpophalangeal (MCP) joint may influence TMC joint contact wear patterns and subsequent development of OA. The aim of this study is to explore the alignment of the MCP joint of the thumb during lateral pinch in order to describe the naturally occurring alignment in a group of healthy volunteers without symptoms.

Methods

One hundred and nine participants were asked to apply a lateral pinch manoeuvre to a pinchmeter, while their thumbs were assessed. Passive hypermobility of the thumb MCP (MCP) joint was assessed, key pinch strength was measured, key pinch position was photographed and the angle of the joints during the assessment was measured.

Results

Four different functional pinch patterns were identified. The most frequent pattern seems to be MCP hyperextension described by Moulton as harmful for the TMC joint. The level of strength obtained did not correspond to the pinch pattern used, and hypermobility of the thumb MCP joint did not determine the position of the thumb during key pinch.

Conclusion

Four different thumb postures were identified during lateral pinch; however, these postures were not associated with any difference in pinch strength. We conclude that the more unstable and mechanically inefficient postures are compensated by functional capacity.

Ligament reconstruction of the Trapezial-metacarpal joint for early arthritis: a preliminary report

PURPOSE

To evaluate the results and determine the efficacy of an alternative ligament reconstruction technique in patients with a symptomatic trapezial-metacarpal joint associated with subluxation and early or limited chondral damage.

METHODS

This retrospective, nonrandomized study was composed of 6 patients, all women with ages between 31-46 years, treated by arthroscopic evaluation and reconstruction of the intermetacarpal and reverse anterior oblique ligament of the trapezial-metacarpal joint, using a strip of flexor carpi radialis tendon. Evaluation at an average follow-up of 18 months (range,12-28 mo) consisted of interview, examination, and computed tomography.

RESULTS

The visual analog pain score, preoperative rest pain, and activity pain improved significantly after surgery. Tip and lateral pinch strength measured 92% compared to the contralateral thumb, and computed tomography showed improved alignment of all joints.

CONCLUSIONS

Our results indicate that ligament reconstruction using the technique described reduced pain, increased strength, and improved the trapezial-metacarpal joint alignment in patients with early symptomatic trapezial-metacarpal joint osteoarthritis associated with joint subluxation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.