Radiographic features and subtypes of congenital thumb duplication type C3 according to Wu et al. and their potential implications for surgical management: new classification and preliminary results.

BACKGROUND: Wu et al. introduced a modified radiographic system that allows classification of all forms of CTD with excellent interobserver and intraobserver reliability. No study to date has evaluated the radiographic characteristics of Wu et al. type C3 CTD with osseous attachment at the level of the metacarpal. OBJECTIVE: This study aimed to evaluate the radiographic features of type C3 CTD according to the system of Wu et al., to describe the different anatomical subtypes of the duplication, and to propose a categorization approach to distinguish diverse surgical strategies based on the radiographic anatomy of this specific subtype of duplication. METHODS: We performed a retrospective analysis of 215 patients (221 thumbs) diagnosed with Wu et al. type C3 CTD at our Institution between 2015 and 2021. We evaluated all CTDs by examining the alignment of the interphalangeal (IP) and metacarpophalangeal (MP) joints and by assessing the presence of abnormal hypertrophic epiphysis of the primary thumb on posteroanterior (PA) radiographs. The proposed classification system has four types: Type I with good alignment of both MP and IP joints, Type II with ulnar deviation of the MP joint, Type III with radial deviation in the MP joint and Type IV with abnormal hypertrophic epiphysis of the distal phalanx of the main thumb with ulnar deviation of the IP joint with or without ulnar deviation of the MP joint. RESULTS: There were 140 male and 75 female patients with CTD (221 thumbs). There were 65 left, 144 right and 6 bilateral forms. The right-to-left, male-to-female and unilateral-to-bilateral ratios were 2.2:1, 1.9:1 and 35.8:1 respectively. The mean age at surgery was 22.3 ± 11.8 months (range, 8-80). The proposed classification system allowed the classification of all CTDs (n = 221). Specifically, 53 fingers were classified as Type I (24%), 136 as Type II (61.5%), 21 as Type III (9.5%), and 11 as Type IV (5%). CONCLUSION: The proposed system is based on radiographic pathoanatomy and complements that of Wu et al. by identifying four distinct subtypes of deformity. It has the potential to improve inter-professional communication and guide surgery in patients with Wu et al. type C3 CTD. However, our results are preliminary and further research is needed to validate them. LEVEL OF EVIDENCE: III.

The Effects of Intra-Articular Triamcinolone and Autologous Protein Solution on Metabolic Parameters in Horses.

Intra-articular corticosteroids are a popular treatment choice for joint-associated pain and inflammation in horses despite recent work on the metabolic effects of these drugs. The goal of this project was to compare metabolic effects between intra-articular (IA) triamcinolone acetonide (TA) and an autologous protein solution (APS). Five mixed-breed geldings (4-9 years) were utilized for this project. Three identical and consecutive 28-day treatment blocks were used, with metacarpophalangeal IA treatments consisting of equal volumes of saline, a commercially available APS, or 9 mg of TA. Regular plasma and serum samples were collected for ACTH, cortisol, glucose, insulin, and thyroid hormone analysis, in addition to thyrotropin-releasing hormone (TRH) and oral sugar tests (OSTs). Significant treatment effects of IA TA were present at 48 h post-injection in both the TRH and the OST. There was also significant suppression by IA TA of baseline ACTH and cortisol between 2 h and 96 h post-treatment, hyperglycemia between 12 h and 48 h, and hyperinsulinemia at 32 h post-treatment. There were no treatment effects with respect to any measured thyroid hormones, nor were there any significant treatment effects of APS noted. Results suggest at least 2 days and up to 7 days should elapse between a single 9 mg IA TA treatment and OST and/or TRH testing. This study found that TA exhibits significant effects on ACTH, cortisol, glucose, and insulin, while the APS does not.

Articular Surface Damage Following Headless Intramedullary Nail Fixation of Proximal Phalanx Fractures.

PURPOSE: Offering the benefits of rigid fixation while minimizing soft tissue dissection, intramedullary implants have become a popular choice among hand surgeons. Their placement often requires traversing or passing in proximity to joint surfaces. This study aimed to assess the damage to the articular cartilage of the base of the proximal phalanx resulting from antegrade placement of threaded headless intramedullary nails. METHODS: A cadaveric study comparing two techniques for antegrade placement of threaded headless intramedullary nails was conducted in 56 digits. The first entailed a single 2.1 mm intramedullary nail placed via the dorsal base of the proximal phalanx, whereas the second used two 1.8 mm intramedullary nails inserted via the collateral recesses of the phalangeal base. All specimens were analyzed for articular surface damage with the cartilage defect measured as a percentage of total joint surface area. Damage to the extensor tendons was also assessed in a subset of specimens. RESULTS: No significant difference in the percentage of articular surface damage was observed, with an average 3.21% ± 2.34% defect in the single 2.1 mm nail group and a 2.71% ± 3.42% mean defect in the two 1.8 mm nails group. There was no articular surface injury in 18% of digits in each group. Damage to extensor tendons was seen in three (9.4%) specimens and in all cases involved either the extensor indicis proprius or extensor digiti minimi. CONCLUSIONS: Hardware insertion using either the dorsal base of the proximal phalanx or the collateral recesses of the phalangeal base both demonstrated minimal articular cartilage damage and infrequent injury to the extensor tendons. CLINICAL RELEVANCE: With proper technique for antegrade insertion into the proximal phalanx, the cartilage defect observed often encompasses only a small percentage of the overall joint surface area.

Surgical Opportunism for Hand Reconstruction Following a Mutilating Injury: A Case Report.

We report our management of a 53-year-old female who suffered a wood planer hand-mutilating injury with significant dorsal soft tissue loss and partial metacarpophalangeal joint (MCPJ) amputations of the thumb, index, and middle fingers. The middle finger was deconstructed for "spare parts" and a vascularized osteochondral graft was utilized to reconstruct the metacarpal articular surface of the index finger proximal phalanx, allowing the pedicled transposition of the index finger to the third metacarpal. The middle finger's distal interphalangeal joint was transplanted non-vascularly to recreate the thumb MCPJ and the elevation of a middle finger fillet flap allowed dorsal wound coverage. The patient did well initially but required ulnar collateral ligament reconstruction with a palmaris longus tendon graft following MCPJ instability 10 months postoperatively. Nonetheless, she progressively regained thumb opposition and pinch grip and continues to have successful aesthetic and functional outcomes six years postoperatively, supporting the efficacy of non-vascularized joint transfers when vascularized options are superfluous or unavailable.

Unveiling a foreign body masquerading as periarticular calcification: a case report.

INTRODUCTION: Evaluating isolated extremity discomfort can be challenging when initial imaging and exams provide limited information. Though subtle patient history hints often underlie occult pathologies, benign symptoms are frequently miscategorized as idiopathic. CASE PRESENTATION: We present a case of retained glass obscuring as acute calcific periarthritis on imaging. A 48-year-old White male with vague fifth metacarpophalangeal joint pain had unrevealing exams, but radiographs showed periarticular calcification concerning inflammation. Surgical exploration unexpectedly revealed an encapsulated glass fragment eroding bone. Further history uncovered a forgotten glass laceration decade prior. The foreign body was removed, resolving symptoms. DISCUSSION: This case reveals two imperative diagnostic principles for nonspecific extremity pain: (1) advanced imaging lacks specificity to differentiate inflammatory arthropathies from alternate intra-articular processes such as foreign bodies, and (2) obscure patient history questions unearth causal subtleties that direct accurate diagnosis. Though initial scans suggested acute calcific periarthritis, exhaustive revisiting of the patient's subtle decade-old glass cut proved pivotal in illuminating the underlying driver of symptoms. CONCLUSION: Our findings underscore the critical limitations of imaging and the vital role that meticulous history-taking plays in clarifying ambiguous chronic limb presentations. They spotlight the imperative of probing even distant trauma when symptoms seem disconnected from causative events. This case reinforces the comprehensive evaluation of all subtle patient clues as key in illuminating elusive extremity pain etiologies.

Metacarpophalangeal Joint Arthroscopy: Indications and Techniques through a Clinical Series.

Background Metacarpophalangeal (MCP) joint arthroscopy has been available for many years but sparingly used in typical orthopaedic and hand surgery daily practice. Difficult problems are solved with this technique in a practical and minimally invasive manner. This study describes our diverse experience and broad clinical applications of MCP arthroscopy as well as clinical results. It aims to highlight this technique as one of the tools for a fully trained hand surgeon, avoiding open management and its high complications rates. Methods We present a retrospective clinical series of 79 patients treated with MCP arthroscopy with a mean age of 44 years old. Demographics, surgery, and clinical outcomes were collected in standardized clinical assessments. Results We divided the sample into 20 articular metacarpal or proximal phalanx acute fracture with full functional fist and range of motion at 60 days after surgery. Regarding collateral tears, 12 were classified as acute and 47 as chronic. Two patients were reoperated for further gain range of motion. Conclusions We present an up-to-date publication of our experience in MCP arthroscopy and its applications, with a low complication rate and excellent clinical results. We encourage hand surgeons to incorporate this technique in MCP joint challenging issues. Level of Evidence IV.

The Validity and Reliability of a Smartphone Application for Measuring Wrist and Metacarpophalangeal Joint Motion.

Background Accurate measurement of the range of motion (ROM) is crucial for guiding upper extremity rehabilitation. Inaccurate measurements can mislead clinicians and harm patient compliance. This study aimed to evaluate the validity and reliability of a smartphone application (Angulus) for measuring wrist and metacarpophalangeal (MCP) joint ROM. Methodology This study included 64 volunteers with no prior wrist injuries. The wrist flexion/extension, radial/ulnar deviation, and MCP joint flexion/extension ROM were assessed by an experienced physiotherapist (Assessor 1) using the Angulus and a standard two-arm goniometer. The validity of Angulus was evaluated by correlating it with the goniometer measurements using the Pearson correlation coefficient. For the reliability analysis, an inexperienced biomedical engineer (Assessor 2) performed the same measurements using Angulus twice in different sessions, in addition to Assessor 1. The intra-rater and inter-rater reliability were tested using the intraclass correlation coefficient. Results The mean age of the participants was 29.5 ± 8.2 years, with 62% being female. The validity of the Angulus app measurements was indicated by the adequate to excellent correlation between the Angulus and goniometer measurements (ranging from 0.44 to 0.81). The intra-rater reliability of the Angulus app was excellent for Assessor 1 (ranging from 0.76 to 0.90) and adequate to excellent for Assessor 2 (ranging from 0.71 to 0.88). The inter-rater reliability of Angulus was excellent (ranging from 0.91 to 0.96). Conclusions Angulus is a valid and reliable method to measure the wrist and MCP joint ROM.

Outcomes of Arthrodesis of the Metacarpophalangeal Joint of the Thumb for Sequelae of Collateral Ligament Injuries: A Series of 18 Cases with 6-Year Follow-Up.

Background: Untreated or insufficiently treated collateral ligament injuries of the thumb metacarpophalangeal (MP) joint can lead to instability or even osteoarthritis. Arthrodesis is one of the treatment options available for the treatment of the sequelae of collateral ligament injuries. The objective of our study was to evaluate the radiological, clinical and functional outcomes of MP joint arthrodesis performed for sequelae of collateral ligament injuries. Methods: We conducted a retrospective, single-centre study and reviewed the files of patients who had a thumb MP joint arthrodesis following a collateral ligament injury between 2011 and 2019. We collected patient's demographic data and the results of the radiological and clinical examinations. Results: Eighteen patients were included in the study. The average age was of 53.6 years and the time between injury to arthrodesis averaged 7 years. Four patients (22%) had nonunion. In the remaining 14 patients with solid union at an average of 72 months follow-up, the visual analogue pain score at rest was 0.14, the thumb opposition was 82%, grip strength 85%, tip pinch 92% and key pinch 79% of the contralateral side. Conclusions: The clinical and functional results of patients with a successful arthrodesis are satisfactory with restoration of good grip and pinch strength. Despite a lack of thumb MP joint flexion, stability allowed force transmission and may be preferred for manual workers. Level of Evidence: Level IV (Therapeutic).

Novel figure-of-eight reconstruction with free tendon graft for unrepairable collateral ligament of the thumb metacarpophalangeal joint.

OBJECTIVES: This study aimed to report surgical technique and clinical outcomes for a novel figure-of-eight collateral ligament reconstruction technique using palmaris longus autograft for chronic irreparable collateral ligament injury of the thumb metacarpophalangeal joint. MATERIAL AND METHODS: The Jobe elbow collateral ligament reconstruction method was adapted for thumb metacarpophalangeal joint collateral ligament reconstruction. Sixteen reconstructions (7 ulnar collateral ligament, 9 radial collateral ligament) using palmaris longus autograft were reviewed retrospectively. Surgery was performed at a mean 12 months post-injury. All 16 patients were followed up for more than 1 year. Metacarpophalangeal joint radial and ulnar deviation, metacarpophalangeal and interphalangeal joint range of motion, key pinch and grip strength, Glickel functional grade and QuickDASH score were evaluated. RESULTS: Preoperative radial or ulnar deviation improved from 19.3° to 5.3° postoperatively. Metacarpophalangeal range of motion improved from 31.5° to 46.6°, and interphalangeal range of motion from 48.4° to 65.6°. Preoperative key pinch and grip strength were respectively 49% and 81% of contralateral values and improved to 82% and 87%. On Glickel grade, 9 cases were excellent and 7 good. CONCLUSION: The novel Jobe-like figure-of-eight reconstruction technique using palmaris longus graft was useful for reconstructing irreparable thumb metacarpophalangeal joint instability without an incision on the opposite side or an additional implant. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Radial Collateral Ligament Laxity of Thumb Metacarpophalangeal Joint Following Trapeziometacarpal Arthrodesis.

PURPOSE: Trapeziometacarpal (TM) arthrodesis may increase adduction motion of the thumb metacarpophalangeal (MCP) joint, causing radial collateral ligament laxity. Stability of the MCP joint is important to the long-term functional outcome after TM arthrodesis. This study assessed preoperative and postoperative radial collateral ligament laxity using dynamic radiographs to confirm whether laxity was exacerbated after surgery and examined whether there is a relationship between the fixation angle of arthrodesis and the degree of laxity. METHODS: Forty-four thumbs in 33 patients who underwent TM arthrodesis and were followed for at least 5 years were studied. Dynamic radiographs in radial adduction-abduction and palmar adduction-abduction were obtained. We defined the midpoint of arc of motion as the fixation angle of arthrodesis in the radial and palmar planes. We measured the intersection angle between longitudinal axis of the first metacarpal (M1) and that of thumb proximal phalanx (P1). P1M1 angle in a palmar adduction view of dynamic radiographs reflected radial collateral ligament laxity in palmar adduction (adduction P1M1 angle). We subtracted a preoperative adduction P1M1 angle from a postoperative adduction P1M1 angle and defined its value as an exacerbated adduction P1M1 angle. RESULTS: Adduction P1M1 angle increased from 9° ± 5° to 18° ± 10°. The median exacerbated adduction P1M1 angle was 7°. Ten thumbs (23%) developed ulnar subluxation of MCP joint in the palmar adduction view of dynamic radiographs. Among them, two thumbs developed osteoarthritis of MCP joint (5%). Fixation angle of the arthrodesis was a mean of 35° ± 7° and 32° ± 9° in the radial arc and palmar arc planes, respectively. There was a positive correlation between increasing adduction P1M1 angle and TM arthrodesis in an increasingly palmarly abducted position. CONCLUSIONS: Radial collateral ligament laxity of thumb MCP joint was exacerbated after TM arthrodesis. Greater fixation angle in palmar abduction resulted in more laxity of the joint. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Complex dorsal metacarpophalangeal joint dislocation associated with proximal metacarpal fracture: case report and review of the literature.

INTRODUCTION: Complex dorsal metacarpophalangeal joint (MCPJ) dislocations are uncommon injuries that mainly affect the index finger and are typically caused by a fall on an outstretched hand. It is exceptional for complex MCPJ dislocation to coexist with a distal fracture of the corresponding metacarpal bone. PRESENTATION OF THE CASE: The authors report a case of a 23-year-old man presented to the emergency, with a complex dorsal metacarpophalangeal joint dislocation of the index associated with a distal metacarpal fracture confirmed by imaging. The patient had an open reduction and internal fixation of the proximal metacarpal fracture. The results were satisfying. DISCUSSION: Dorsal MCP joint dislocations are rare, primarily affecting the index and little fingers, and are typically caused by a fall on an outstretched hand. Complex dislocations, characterized by irreducibility, involve structures forming a "noose" around the metacarpal head. Fractures associated with these dislocations are uncommon. Early diagnosis is crucial for better long-term functional outcomes. Radiographic imaging, including three different views, is necessary for accurate diagnosis. Surgery is usually required, with different approaches depending on the case. Arthroscopic techniques can be used when reduction is challenging. Timely surgical intervention yields the best results. Stiffness, osteoarthritis, osteonecrosis, and growth arrest in pediatric cases are the main complications. CONCLUSION: Complex dorsal metacarpophalangeal joint (MCPJ) dislocations are rare. Open reduction is typically necessary for optimal outcomes. Complications such as stiffness, osteoarthritis can arise, emphasizing the importance of accurate diagnosis and appropriate management.

Spontaneous Idiopathic Bilateral Sagittal Band Rupture: A Case Report.

Introduction: Extensor tendon subluxation or dislocation resulting from sagittal band rupture can be associated with snapping, catching, locking, pain, and swelling of the finger. Several etiologies were reported in the literature, with frequent mention of a traumatic rupture caused by a direct blow at the level of the metacarpophalangeal joint (MCPJ). The other causes of sagittal band injuries are degenerative disease, congenital infection, and rheumatoid arthritis. To our knowledge, we report the first case of spontaneous idiopathic bilateral sagittal band rupture. Case Report: We, herein, present the case of a seronegative 29-year-old female who presented with pain and swelling in the dominant hand for 4 days. Conclusion: Upon examination, she was found to have bilateral dislocation of the extensor tendons at the level of the (MCPJ) of the third and fourth digits. Any underlying cause was excluded, and the diagnosis was confirmed with a dynamic ultrasound study.

Biological Versus Nonbiological Reconstruction of the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint: A Retrospective Study.

PURPOSE: The purpose of this study was to compare clinical and radiologic outcomes of biological ligament reconstruction (BLR) versus nonbiological ligament reconstruction (NBLR) for chronic injuries involving the ulnar collateral ligament of the thumb's metacarpophalangeal joint. METHODS: Forty-two patients who underwent static BLR (n = 24) or NBLR (n = 18) were included in this retrospective analysis. Preoperative, postoperative, and contralateral thumb measurements (clinical evaluation, radiographs, and subjective outcome questionnaires) were compared over a mean of 38 months of follow-up. RESULTS: Average postoperative thumb metacarpophalangeal and interphalangeal joint ranges of motion were 2° to 54° and 0 to 71°, respectively, for BLR and 0° to 58° and 0° to 71°, respectively, for NBLR. Average grip and pinch strengths, relative to the unaffected hand, were 102% and 84% versus 103% and 89%, respectively. All patients demonstrated stability with a firm end point, compared with the unaffected thumb. The average Quick Disabilities of the Arm, Shoulder, and Hand score among all patients was 12 for the disability/symptom module, 0 for the sports module, and 17 for the work module. Stiffness was reported among four patients, and no patient sustained wound-related issues or other complications. CONCLUSIONS: Nonbiological ligament reconstruction of the thumb ulnar collateral ligament generates short-term outcomes comparable with those of BLR, potentially allowing for expedited recovery and rehabilitation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

U-shaped kirschner wire transfixation: effective treatment for Skier's thumb.

BACKGROUND: Skier's thumb is a type of injury to the ulnar collateral ligament of the metacarpophalangeal joint of the thumb, which can result in bone fragmentation and joint instability. OBJECTIVE: The objective of this study was to compare the traditional Kirschner wire fixation method with the U-shaped Kirschner wire method for treating small bone fragments with displacement, rotation, or instability in skier's fractures. METHOD: A retrospective study was conducted on 30 patients with skier's thumb who were treated at Tianjin Hospital from January 2019 to December 2021. Patients were divided into two groups: Group A received traditional Kirschner wire fixation, while Group B received U-shaped Kirschner wire fixation. Functional assessments and complications during the perioperative period were evaluated. RESULTS: Both surgical methods significantly reduced postoperative pain and increased joint range of motion. Group B had a lower incidence of pain during follow-up and showed significant functional improvement in Tip-pinch and Grip tests compared to Group A. U-shaped Kirschner wire fixation significantly reduced complications during the perioperative period. CONCLUSION: The U-shaped Kirschner wire internal fixation is a safe and effective treatment for the thumb proximal phalanx base ulnar side avulsion fracture.

Long-Term Implant Fracture Rates Following Silicone Metacarpophalangeal Joint Arthroplasty in Rheumatoid Arthritis.

PURPOSE: The primary objective of this study was to compare the long-term survival rates of silicone metacarpophalangeal (MCP) arthroplasties between two major implants in patients with rheumatoid arthritis, using implant fracture as an end point. We also evaluated the difference in postoperative function between patients with fractured and intact implants as a secondary objective. METHODS: A retrospective cohort study was conducted on 372 fingers of 133 hands that underwent silicone MCP arthroplasty between January 2000 and June 2019 (mean follow-up, 7.6 years). The survival rates of Swanson-type and Sutter-type implants were compared, using implant fracture as the end point after a radiographic evaluation. Clinical measures and upper limb functional assessments using the Disabilities of the Arm, Shoulder, and Hand (DASH) score were performed in the nested cohort. RESULTS: The 10.6-year survival rates for implant fracture of Swanson- and Sutter-type implants were 86.2% and 9.4%, respectively, with significantly higher survival noted for Swanson-type implants. The Sutter-type implant showed increased susceptibility to fracture in all four fingers compared to the Swanson-type implant. Implant fractures were primarily observed at the stem-hinge junction. There were no significant differences in upper limb function between the fractured and intact implant groups. CONCLUSIONS: Sutter-type implants were found to be more prone to fracture compared with Swanson-type implants. However, implant fractures did not significantly affect upper limb function. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognosis IV.

High Fracture Rate of AVANTA Silicone Implant Following Arthroplasty of the Thumb MCP Joint of Rheumatoid Arthritis Patients with Boutonniere Deformities.

We retrospectively investigated the mid-term outcomes of arthroplasty using the AVANTA silicone implant for thumb metacarpophalangeal (MCP) joints with boutonniere deformity in patients with rheumatoid arthritis (RA). This study involved 36 thumbs of 33 RA patients with a mean follow-up period of 5.1 years (range, 2.0-13.3). Postoperatively, the mean extension was significantly increased and the mean flexion was significantly decreased (p<0.001, p<0.001, respectively), resulting in the mean arc of range of motion (ROM) shifting in the direction of extension after surgery. Implant fracture was observed in 10 thumbs (28%), and 4 of these (11%) underwent revision surgery. The survivorship with implant fracture and revision surgery as endpoints were 73.4% and 91.8% at 5 years, respectively. The preoperative arc of ROM and the postoperative flexion range of the implant-fracture group were significantly greater than those in the no-implant-fracture group (p=0.039, 0.034, respectively). These results suggest the importance of patient education and careful rehabilitation to prevent excessive flexion. Overall, the AVANTA silicone implant showed a relatively high rate of implant fracture at our institute.

The Application of Sesamoid Position in Diagnosing Thumb Metacarpophalangeal Joint Dorsal Dislocation: A Retrospective Study.

OBJECTIVES: The position of sesamoid of thumb metacarpophalangeal (MCP) joint changed clearly when the joint was dislocated dorsally. However, the significance of sesamoid location in diagnosing joint dislocation was unclear. The present study aimed to explore the positional relationship between sesamoid bone and thumb metacarpophalangeal joint in normal and dorsal dislocation joints. METHODS: Between January 2018 and August 2023, we collected 60 isometric plain films from sixty outpatients and reviewed 56 anisometric plain films from twenty-eight emergency patients with dorsal dislocation of thumb MCP joint at Tianjin Hospital, then took measurements on the hand X-ray images. The sesamoid length on its longitudinal axis was defined as DP, the distance between the distal edge of sesamoid and thumb MCP joint was defined as DJ, and the ratio of DJ and DP was R. An independent-samples t-test and paired-samples t-test was utilized to analyze difference among data groups. RESULTS: The 60 isometric images were from 30 male and 30 female outpatients with normal bone structure in their hands, and the 56 anisometric images of the 28 emergency patients included both preoperative and postoperative materials. Among the outpatients, the actual distance between the distal edge of sesamoid and thumb MCP joint space (DJ) was 2.09 mm and 1.40 mm in males and females, respectively. The authentic average length of sesamoid (DP) was 4.46 mm in males and 4.22 mm in females. The average value of R (the ratio of DJ and DP) in males and females was 0.49 and 0.34, respectively. There were gender-related statistical differences in DJ (p < 0.01) and R (p=0.01), but no statistical difference in DP (p > 0.05). For the 28 emergency patients, the mean value of R was -0.47 before joint reduction and 0.58 after joint reduction, with statistical difference between them (p < 0.01). CONCLUSIONS: There was significant difference in the relative position between sesamoid and thumb MCP joint when joint dislocation and joint reduction. The distal edge of sesamoid beyond thumb MCP joint could be an evidence in diagnosing joint dorsal dislocation. The distal edge of sesamoid below thumb MCP joint could be an evidence of joint reduction.

Complex Metacarpophalangeal Joint Dislocation (Kaplan's Lesion) of the Index Finger in a 5-year-old Patient: A Case Report.

Introduction: This report highlights a rare case of complex metacarpophalangeal (MCP) joint dislocation, commonly referred to as Kaplan's lesion. This type of dislocation typically results from a hyperextension injury and requires surgical intervention as closed maneuvers are unsuccessful in reducing the dislocation. Surgical reduction for complex MCP joint dislocations is commonly done through classic volar or dorsal approaches. This report presents a case of a complex MCP joint dislocation and the surgical approach taken to address the issue. Case Report: We present a case of a complex MCP joint dislocation in a 5-year-old male patient who sustained a hyperextension injury to his index finger. The patient underwent open reduction surgery using a volar approach due to the buttonholing of the phalangeal head through the volar plate and blockage between the flexor tendons and lumbrical muscle. Following the procedure, the joint was immobilized in a palmar splint at 30° flexion for 2 weeks before being allowed unrestricted mobilization. At the 4-week follow-up, the patient reported being pain-free and had regained nearly full range of motion in the index finger MCP joint. Conclusion: Although there are multiple techniques to address complex MCP dislocation, the classic volar approach is still considered an effective treatment option for pediatric patients with this injury. In such cases, open reduction through a volar approach can enable surgeons to access the joint and address complex dislocations, which are often difficult to manage with closed reduction alone. Consequently, this surgical approach can help achieve a successful reduction and restore the joint's functionality. Therefore, despite the availability of alternative approaches, the classic volar approach should still be considered as a viable option for treating complex MCP joint dislocations in the pediatric population.

Painful snapping of the middle finger caused by hyperplasia of the ulnar lateral band: A case report.

Snapping of fingers can be caused by pathologies such as stenosing flexor tenosynovitis. However, snapping symptoms in the metacarpophalangeal (MP) joint caused by hypertension and hyperplasia of the lateral band are rare. We present a 26-year-old female with symptoms of painful snapping of the middle finger. When the finger was actively flexed from the hyperextension of the MP joint, the ulnar lateral band was prominent, and a snapping phenomenon occurred. The cause of the snapping finger was considered to be tightness of the ulnar lateral band, and surgery was planned. Intraoperatively, the ulnar lateral band was tense and hyperplastic. The snapping phenomenon disappeared immediately after the resection of the lateral band. It is important to consider this condition as one of the differential diagnoses of snapping finger when the patient complains of an atypical snapping phenomenon.

Locking of the metacarpophalangeal joint: A comprehensive review of the literature.

Locked metacarpophalangeal joint is an uncommon phenomenon with many possible etiologies. Diagnosis can be difficult because of the many more common pathologies (trigger finger, sagittal band lesion, etc.) that can lead to a clinical picture that may resemble the locked metacarpophalangeal joint. Once the differential diagnoses have been eliminated, the etiology of this blockage must be determined and the surgical procedure must be oriented. The origin of the problem is often difficult to determine, especially since standard imaging tests are often not very informative. Several clinical forms are possible, with blockages in extension or flexion, but which will have a disabling functional impact on the overall function of the hand. Currently, there is no gold standard for the management of this condition. In this study, we performed a review of the literature in order to better understand the different possible etiologies but also to analyze the different diagnostic and therapeutic management. LEVEL OF EVIDENCE: IV.