Anterior Oblique Ligament Research Articles

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

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. 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. 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). 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.

Transverse ligament of the elbow joint: an anatomic study of cadavers

The medial collateral ligament of the elbow joint consists of the anterior oblique ligament (AOL), posterior oblique ligament (POL), and transverse ligament (TL). This study aimed to clarify the structure of the TL, with a focus on the continuity between the TL and AOL. A total of 42 cadavers (18 males, 24 females) were dissected at Aichi Medical University between 2016 and 2018. Cases of elbow deformity or atrophy were excluded, and 60 elbows (15 males, 15 females) were dissected to assess the fibers of both the TL and AOL using a stereomicroscope. The TL could be detected in all elbows and always continued to the AOL. The TL was classified into 2 types. The TLs continuing to the distal half of the AOL (type I) were observed in 44 elbows (73.3%), whereas the TLs continuing to the entire AOL (type II) were found in 16 elbows (26.7%). Type II TLs were significantly more frequently observed in the elbows of females than in those of males (P = .041). Stereomicroscopic observation revealed that the TL fibers entered perpendicularly to the distal half of the AOL in both types. The TL frequently continues to the distal half of the AOL, but rarely continues to the entire AOL. The TLs continuing to the entire AOL were more frequently detected in the elbows of females than in those of males. The TL possibly contributes to medial elbow stability via its continuity to the AOL.

Histopathological analysis of the synovium in trapeziometacarpal osteoarthritis.

Dorsoradial and anterior oblique ligaments were harvested during surgery in 13 patients with symptomatic trapeziometacarpal osteoarthritis, which had been graded preoperatively by a modified Eaton-Littler radiographic grading. Ligaments, including the periligamentous synovium, were stained with S100 protein, neurotrophic receptor p75, protein gene product 9.5, calcitonin gene related peptide, acetylcholine, substance P, neuropeptide Y, noradrenaline, N-methyl-D-aspartate-receptor and Met/Leu-enkephalin. The synovium was classified as showing no, low-grade or high-grade synovitis. Free nerve endings had higher immunoreactivity for substance P than for N-methyl-D-aspartate-receptor, enkephalin and noradrenaline. The synovial stroma had less immunoreactivity for N-methyl-D-aspartate-receptor than for noradrenaline, substance P and calcitonin gene related peptide. There was no relation between the grade of osteoarthritis and the visual pain analogue scale, synovitis score, immunoreactivity of all antibodies and quantity of free nerve endings or blood vessels. Synovium in trapeziometacarpal joint osteoarthritis produces several neuromediators causing a polymodal neurogenic inflammation and which may serve as biomarkers for osteoarthritis or therapeutic targets.

Ulnar collateral ligament insufficiency affects cubital tunnel syndrome during throwing motion: a cadaveric biomechanical study

In throwing athletes, cubital tunnel syndrome and insufficiency of the ulnar collateral ligament (UCL) are common pathologic processes of the elbow. The objective of this study was to investigate the effect of UCL tears on ulnar nerve elongation in the simulated throwing position. Eight fresh frozen cadaveric upper limbs were tested at the simulated late cocking to acceleration phase in the throwing motion using an elbow testing system. Elbow valgus laxityand ulnar nerve length and strain under 2 Nm of applied valgus torque (maximum torque in cadaveric elbow) were evaluated. Paired t-tests were used to compare all data between intact UCLs and UCLs after complete transection of the anterior oblique ligament. Linear regression analysis was used to investigate relationships between elbow valgus laxity and ulnar nerve strain. Elbow valgus laxity significantly increased after transection of the UCL. Ulnar nerve length after UCL transection was significantly greater than that in the intact condition at 60° (P = .006) and 90° of elbow flexion (P < .0001). In addition, ulnar nerve strain was positive (increased) at 60° and 90° of elbow flexion. Maximum ulnar nerve strain at 90° of elbow flexion was 3.9% ± 0.9% when the UCL was intact and 6.8% ± 0.7% after transection. UCL transection yielded significant positive correlation between elbow valgus laxity and ulnar nerve strain (P = .006; r = .4714). Increased elbow valgus laxity due to UCL insufficiency may cause elongation of the ulnar nerve and exacerbate cubital tunnel syndrome during the throwing motion.

Posttraumatic contracture of the elbow and cubital tunnel syndrome associated with heterotopic ossification in the anterior oblique ligament of the medial collateral ligament: A case report

Posttraumatic contracture of the elbow and cubital tunnel syndrome associated with heterotopic ossification in the anterior oblique ligament of the medial collateral ligament: A case report

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.

Bennett Fractures: A Biomechanical Model and Relevant Ligamentous Anatomy.

This study examined a palmar beak fracture model to determine which thumb carpometacarpal (CMC) joint ligament is the primary ligament relevant to the pattern of injury. Six fresh-frozen cadaveric wrists were used. The radius, ulna, and first metacarpal were secured and tested with a materials testing system, holding the wrist in 20° extension, 20° ulnar deviation, and 30° palmar abduction of the first metacarpal. Testing consisted of preconditioning cycles followed by compressive loading at 100 mm/s. We confirmed fractures with fluoroscopy and dissected the specimens to examine the CMC joint ligaments. The metacarpal was stressed through a range of motion to determine which maneuvers reduced or displaced the fractures. Our model successfully created palmar beak fractures in all cadaveric specimens. All fractures were displaced and intra-articular. The anterior oblique ligament (AOL) was thin and partially attached to the palmar beak fracture fragment. The ulnar collateral ligament was attached in its entirety to the fracture fragment and represented a thicker, more robust ligament compared with the AOL. Radial abduction and pronation of the metacarpal reduced fracture displacement. Extension of the CMC joint or tensioning the AOL did not decrease fracture displacement. This model successfully created a reproducible and clinically relevant palmar beak fracture in a biomechanical setting. The primary ligament attached to the palmar beak fracture fragment was the ulnar collateral ligament, and not the AOL as previously described. These findings suggest that the AOL may not be a substantial contributor to palmar beak fracture morphology. A refined description of the ligamentous anatomy of the palmar break fracture enhances opportunities for improved reduction and treatment of this common hand injury.

The Stabilising Effect of the Anterior Oblique Ligament to Prevent Directional Subluxation at the Trapeziometacarpal Joint of the Thumb: A Biomechanical Cadaveric Study.

The trapeziometacarpal joint (TMCJ) is inherently unstable, relying on ligament restraint to prevent subluxation. Subluxation of the thumb in a dorsoradial direction is often observed in clinical practice, either after acute ligament injury or more commonly with osteoarthritis (OA). This subluxation follows loss of function of trapeziometacarpal ligaments that stabilise this joint, resisting the deforming force of abductor pollicis longus (APL). The exact ligaments that stabilise and prevent the thumb from the pull of APL causing dorsoradial subluxation remain unknown, although the anterior oblique ligament (AOL) has been implicated. The aim of this study was to measure the direction of subluxation resisted by the AOL. In this study we used cadaveric limbs and custom made biomechanical testing to measure the influence AOL has in stabilising the thumb against subluxation in three planes: radial, dorsal and dorsoradial. Three fresh frozen hands were dissected to expose the TMCJ, leaving all ligaments, capsule and APL attachment in place. The force required to create a displacement of 5mm between the first metacarpal and the trapezium in these three planes was measured before and after AOL division. The average force to displace in the dorsoradial plane prior to division was 6.68N, and a statistically significant reduction to 1.15N (P<0.001) was found after division of the AOL. A statistically significant increase in force (P<0.001) from 2.89N to 4.04N was seen in the radial plane, while no change was seen dorsally (P=0.98), with average forces of 2.74N and 2.62N found pre and post division. There is clinical significance in reporting quantifiable data in this field, as subluxation of the thumb is often seen with OA. The results of our study provide support for surgical reconstruction of the AOL as the primary surgical stabilizer against dorsoradial subluxation of the thumb.Level of evidence: III.

Anatomy and Biomechanics of the Thumb Carpometacarpal Joint

This article describes the anatomy and biomechanics of the thumb CMC joint, which is also often referred as the thumb trapeziometacarpal joint. The complexity of its anatomy, function, kinesiology, and stability allows humans to obtain the unique prehensile ability of thumb opposition with stable pinch. The biconcavoconvex saddle shape joints with offset mechanical axes allows a motion in 3 planes with only 2 axes of control. It is important to appreciate the unique oseous anatomy of the thumb CMC joint and role of supporting ligaments. Although many previous articles reported on the anterior oblique ligament as a primary stabilizer of the thumb CMC joint, increasing evidence has supported the dorsal ligament complex is its primary stabilizer. Understanding those key features of the thumb CMC joint is essential to adequately treat its pathology, such as fracture dislocation, ligamentous injury, and degenerative osteoarthritis.

Trapeziectomy and Suspensionplasty Using an Acellular Dermal Matrix Allograft

Trapeziectomy and suspensionplasty with or without interposition is the most commonly performed surgery in the United States for symptomatic thumb carpometacarpal joint arthritis that has failed conservative treatment. The anterior oblique ligament is traditionally reconstructed using tendon autograft to stabilize the first ray after trapeziectomy, but concerns regarding donor site morbidity have led to the use of commercially available products. Acellular dermal matrix (ADM) allograft has been successfully and safely used in several orthopaedic procedures including anterior oblique ligament reconstruction and interposition following trapeziectomy. The use of ADM negates the need to harvest tendon autograft and therefore reduces both morbidity and operative time while also providing the ability to perform a consistent procedure in both primary and revision cases. In this article, we describe our preferred surgical technique of trapeziectomy and suspensionplasty using an ADM allograft.

Biomechanical comparison of anterior oblique ligament versus dorsal radial ligament reconstruction of the trapeziometacarpal joint

Objective To compare the axial shortening resistance of anterior oblique ligament and dorsal radial ligament reconstruction of trapeziometacarpal joint after trapezium excision for the patients with osteoarthritis of trapeziometacarpal joint, and to determine which method was more stable. Methods Twenty cases of male adult fresh cadaver hand specimens were dissected. After the trapezium excision, ten cases of anterior oblique ligament and ten cases of dorsal radial ligament were reconstructed using half bundle of flexor carpi radialis tendon. Biomechanical testing was performed to obtain maximum load when the first metacarpal sinking 10 mm and to determine which ligament reconstruction method yielded larger axial shortening resistance. Results After the trapezium excision, the maximum load of the dorsal radial ligament reconstruction when the first metacarpal sinking 10 mm was (67.67±7.98) N and that of the anterior oblique ligament reconstruction was (77.11±8.25) N. The difference between two groups was significant (P<0.05). Conclusion After the trapezium excision, anterior oblique ligament reconstruction using flexor carpi radialis tendon can achieve more stable trapeziometacarpal joint. We should reconstruct the anterior oblique ligament firstly. Key words: Thumb; Carpometacarpal joints; Ligaments; Biomechanics

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.

InVivo 3-Dimensional Kinematics of Thumb Carpometacarpal Joint During Thumb Opposition.

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. 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. 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 thefirst 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 POLlengthened, the lengths of other ligaments did not change significantly. 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. 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.

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.

Influence de la réconstruction du ligament radio-dorsal sur la stabilité de l’articulation trapeziometacarpien

Introduction Biomechanical and anatomical research has shown that the dorsal radial ligament (DRL) is thicker and stiffer then the anterior oblique ligament (AOL). The DRL as the key stabilizing structure of the trapeziometacarpal (TMC) joint has been documented extensively. The aim of the current study is to quantify the influence of a surgical DRL reconstruction on TMC stability in non-traumatic instability patients. Methods Eight patients with symptomatic TMC instability but no radiographic signs of osteoarthritis were recruited and dynamic CT scans of the thumb were made during active abduction-adduction, flexion-extension and two functional grip task using a radiolucent jig. After image acquisition and segmentation, metacarpal translation was expressed relative to the trapezial articular surface. In addition, intersection points and inclination angles of instantaneous helical axes with an anatomically defined plane were determined to facilitate motion comparison between subjects. Scans were acquired before and 6–12 months after reconstruction of the DRL. Results During active motion, there is motion at both the trapeziometacarpal (TMC) and trapezioscaphoid (STT) joints. However, joint motion patterns, defined as changes in helical axis inclination angles during opposition, differ between patients. In most patients, dorsal luxation of the first metacarpal (MC1) could be clearly seen and quantified during the full range of motion, as well as during function grip tasks. Furthermore, dorsal luxation results in higher point loading of TMC cartilage as could be demonstrated by mapping the changes in articular contact area for each active motion. After DRL reconstruction, patients report improvement in pain and subjective stability in the joint. Analyses of the dynamic CT scans demonstrate reduced translation and luxation of MC1 in all patients as well as reduced cartilage point loading. Conclusion After DRL reconstruction, luxation of MC1 was reduced in all patients. We quantified movement in both TMC & STT joint, suggesting that pathologies at the TMC joint could lead to compensatory movements at the more proximal joints or vice versa. Simple DRL reconstruction is an attractive alternative for the more invasive anterior oblique ligament reconstruction described by Eaton, serving the same purpose, stabilizing the CMC joint. Future research should investigate if TMC instability and its altered kinematics lead to secondary joint problems (e.g. osteoarthritis) if left unattended.

Modified Eaton-Littler’s Reconstruction for Traumatic Dislocation of the Carpometacarpal Joint of the Thumb—A Case Report and Review of Literature

Isolated traumatic dislocation of the carpometacarpal joint of the thumb is an uncommon injury. Left untreated, resulting mechanical instability of this joint interferes with normal function of the hand and can lead to articular degeneration of the joint. Most are amenable to closed reduction with or without supplementary pinning. We present a case of a 21year old female patient with continual instability of the carpometacarpal joint of her right thumb, following closed reduction and pinning. Surgical stabilization was achieved by anterior oblique ligament reconstruction using a Modified Eaton- Littler's technique. At 1year follow-up evaluation the patient was pain free with no clinico-radiological evidence of instability.

The Pathophysiology of the Osteoarthritis of the Thumb

Introduction: More than 16 ligaments around the joint have been described by Bettinger et al. (1999); four ligaments and the joint capsule are the main stabilizers of the trapeziometacarpal (TM) joint. These ligaments are the dorsoradial (DRL), intermetacarpal (IML), anterior oblique (AOL), and posterior oblique ligaments (POL). The importance of each of these ligaments in the stability of the TM joint is debatable. The purpose of the study was (1) to describe the anatomy and dimension of the thumb carpometacarpal (CMC) joint ligaments, (2) to assess the ligament lesions and the degree of subluxation of the CMC joint, and (3) to measure cartilage thickness in the trapezium and metacarpal and pattern of chondromalacia and osteoarthritis (OA). We investigated the role that these ligament ruptures play in the pathophysiology of the OA. Methods: Twenty-five fresh-frozen cadaver hands were dissected of all soft tissue to expose the joint capsule and ligaments of the TM joint. There were 14 male and 11 female with mean age of 67 years (range, 51-94 years). The dissection was performed under ×4.5 loupe magnification. We showed the main ligaments and also the ligament ruptures in IML, AOL or beak ligament, dorsal oblique ligament (DOL), and DRL. We described the location of the ligament tears and whether these ruptures were partial or total. The ligament ruptures and the metacarpal translation associated with these ruptures were measured (mm). Cartilage thickness in the trapezium and metacarpal of specimens was assessed. We described the degree of degenerative changes using the stanging protocol to describe visual degeneration by Koff et al. (2003). We investigated the relationship between the ligament ruptures and the area of chondromalacia and OA. Statistical analysis of data was performed with the chi-square test, and the level of significance was P &lt; .05. Results: Seven principal ligaments of the thumb CMC joint were identified using Berger’s principles (200s1). Ligament lesions were found in all 25 specimens. Isolated rupture of the AOL was found in 7 (28%), isolated rupture of the DRL was found in 10 (40%), isolated rupture of the IML was found in 2 (8%). Combined rupture of the AOL and IML was found in 2 (8%) and combined rupture of the DRL and IML in 4 (16%) joints. The mean metacarpal displacement due to isolated rupture of the ligaments was DRL 17 mm ( P = .006), AOL 11 mm, POL 0.5 mm, and IML 0.4 mm. We found 2 cases OA stage I, 7 cases OA stage II (1 IIa, 3 lib, and 3 IIc), 9 OA stage III, and 7 OA stage IV. There was a relationship between the presence of a tear in the DRL and the presence of OA in the radial quadrants ( P = .032). Conclusion: These observations suggest a translation of metacarpal on trapezium in the production of arthritic lesions and support a hypothesis that pathologic joint instability could be a cause of CMC OA. This study suggests that repairing the DRL during ligament reconstruction of the CMC joint should be considered.

Risk of Fragments in Ulnar Collateral Ligament Injuries Of Baseball Players

Objectives:Many baseball players with UCL injuries have avulsed persistent fragments by throwing disorder in the youth. The presence of fragments results in discontinuity of the medial elbow joint support structures; therefore, a ligament with fragments is considered more fragile than the normal ligament. This study compared three types (fragment, malunion, and normal) of throwing-related UCL injuries and prospectively examined the risk of surgical treatment.Methods:The total subjects were 439 baseball players (age 14-30 years; mean age, 17.5 years) diagnosed with UCL injuries at our hospital between November 2009 and June 2013. At the time of the initial examination, the medial epicondyle was assessed on plain frontal radiographs with the elbow flexed at 45°. Based on this assessment, subjects were divided into three groups: group with persistent fragments (fragment [F] group), group with complete union following avulsion fracture (malunion [M] group), and a group with no history of avulsion fracture (normal [N] group). Each patient’s ability to return to playing baseball was assessed after at least 3 months of systematic rehabilitation. Subjects who failed to comply with rehabilitation, played only recreationally, or with pain in sites other than the elbow were excluded. In this series, 220 cases were left for investigation. The Conway-Jobe scale was used as a standard to assess the return to playing after conservative therapy; subjects with excellent or good ratings were deemed able to return to playing baseball, whereas those with fair or poor ratings were deemed unable to return to playing baseball. The return rates were calculated for the F, M, and N groups respectively. The Magnetic resonance (MR) images consisted of three slices along the long axis of the anterior oblique ligament; these images were used to classify injuries as severe or mild, which were then compared with each other. SPSS 20.0 was used to perform the statistical analysis.Results:A total of 107 subjects were able to resume playing competitive baseball game, whereas 113 subjects were unable to resume playing and underwent surgical treatment (Table.1). The F group demonstrated a significantly lower return rate (p < 0.01) (Table.2). The F group demonstrated a significantly higher percentage of severe injuries (p < 0.01) (Table.2).Return rates in the mild and severe injury groups were 79.1% and 29.1%, respectively, demonstrating a significant difference (p < 0.01) (Table.3). Not surprisingly, the return rate among subjects with severe injuries in the F group was a mere 14.3% (7/49).Conclusion:The results of the present study demonstrated that the presence of fragments in UCL injuries tended to increase the severity of UCL injuries and significantly reduced patient the return rates of competitive game after conservative therapy. Therefore, this exacerbation of UCL injuries is considered a result of persistent medial epicondylar fragments in young baseball players.

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.

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.