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.

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.

Role of inflammatory burden and treatment on joint space width in psoriatic arthritis-a high-resolution peripheral quantitative computed tomography study.

BACKGROUND: To investigate the relationship between disease-related parameters and joint space width (JSW) on high-resolution peripheral quantitative computed tomography (HR-pQCT) in psoriatic arthritis (PsA) patients. METHODS: PsA patients who underwent HR-pQCT examination of the second to fourth metacarpophalangeal joint (MCPJ 2-4) were recruited in this cross-sectional study. The joint space metrics included joint space volume (JSV), mean, minimum, and maximum JSW, JSW asymmetry, and distribution. Correlation analysis and multivariable linear regression models were used to determine the association between disease-related variables and JSW. RESULTS: Sixty-seven patients [37 (55.2%) males; median (IQR) age: 57.0 (53.0, 63.0); median disease duration: 21 (16, 28) years] were included in this analysis. Multivariable linear regression analysis demonstrated that males had larger JSV (MCPJ 2-4), mean (MCPJ 4), and maximum JSW (MCPJ 3). Longer disease duration (MCPJ 2-3) and higher ESR values (MCPJ 3) were negatively associated with mean and maximum JSW, while higher damage joint count was negatively associated with mean and minimum JSW (MCPJ 2). Use of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) was negatively associated with minimum JSW (MCPJ 3) while use of biologic DMARDs (bDMARDs) was positively associated with minimum JSW (MCPJ 2). CONCLUSION: Higher inflammatory burden as reflected by longer disease duration, higher ESR levels, and damage joint count was negatively associated with mean, maximum, and minimum JSW, while suppression of inflammation using bDMARDs seems to limit the decline in JSW.

[Trigger finger-pitfalls and differential diagnosis]. / Der schnellende Finger ­ Pitfalls und Differenzialdiagnostik.

The differential diagnosis of a trigger finger presents a clinical challenge. This case depicts a 32-year-old male patient who presented with persistent snapping of the right index finger at the metacarpophalangeal joint without localized tenderness despite previous surgical A1-annular ligament release. CT diagnostics demonstrated a prominent articular tuberosity. The MRI showed no pathological findings. Surgical revision with concomitant excision of the tuberosity restored smooth mobility of the index finger.

Inter- and Intra-observer Agreement of Visual Estimation, Goniometric and Radiographic Measurement of Passive Thumb Metacarpophalangeal Joint Hyperextension.

Background: Reliable methods for measuring range of motion is important for hand therapists. Currently, there is no gold standard for the measurement of thumb metacarpophalangeal joint (MCPJ) hyperextension. We hypothesised that visual and goniometric measurements of thumb MCPJ hyperextension vary greater than 10° from radiographic measurements, and between observers. Methods: Twenty-six fresh-frozen hands were measured by a senior orthopaedic resident and fellowship trained hand surgeon. Passive thumb MCPJ hyperextension was measured by visual estimation, goniometry and axis measurement on a lateral thumb radiograph. Raters were blinded to each other's and their own prior measurements. Descriptive statistics were recorded for measurement type and inter-observer agreement using a two-way intra-class correlation coefficient (ICC). Intra-observer agreement was calculated using concordance correlation coefficient (CCC). Bland-Altman plots identified trends, systemic differences or potential outliers. Results: Mean measurements for both raters were similar for visual estimation and radiographic measurements. Mean goniometric measurements were twice as high for Rater B, and closer to radiographic measurements. For both raters, mean radiographic measurements were 10° greater than the other two methods. For inter-rater agreement, measurements were within 10° most frequently with radiographic measurement, then visual estimates, and least by goniometer measurements. Rater B had better agreement comparing visual and goniometric to radiographic measurements. Conclusions: Radiographic measurement has the best inter-observer agreement and precision for evaluating passive thumb MCPJ hyperextension, especially considering adjunct corrective procedures when performing a soft-tissue basal joint arthroplasty. Rater experience improves precision, but there is still poor agreement between visual estimates and goniometer measurements compared to radiographic measurements, as the former two underestimate hyperextension by 10°. Development of a standard method of clinical measurement is needed to improve reliability.

Does Irreducibility Always Mean a Complex Dislocation? An Analysis of 33 Pediatric Metacarpophalangeal Joint Dislocations.

BACKGROUND: Previous failed reduction and certain radiographic indicators historically have been used to differentiate simple and complex metacarpophalangeal joint (MPJ) dislocations in children, the latter of which warrants open reduction. This investigation aimed to determine the necessity for open reduction with these indicators and establish a new treatment algorithm and educational focus for these rare injuries. METHODS: A 12-year retrospective study was conducted on all children with MPJ dislocations at a single pediatric hospital. The rates of successful closed reduction, number of reduction attempts, and radiographic findings were detailed. Operative details and postoperative outcomes were also gathered. RESULTS: Thirty-three patients with a mean age of 11.1 years were included. Most were male [ n = 27 (82%)] and had undergone two or more previous reduction attempts at an outside facility. Stable closed reduction was then achieved outside of the operating room in five patients and in the operating room under general anesthesia in another 14, for a total of 19 of 33 patients (57.6%). The thumb was injured most often [ n = 19 (57.6%)] and more likely to undergo successful closed reduction ( P = 0.04). There was no relationship between number of previous reduction attempts and ability to achieve closed reduction ( P = 0.72). Neither joint-space widening nor proximal phalanx bayonetting was correlated radiographically with failure of closed reduction ( P = 0.22 and P = 1, respectively). CONCLUSIONS: This study supports closed reduction of pediatric MPJ dislocations in the operating room under general anesthesia before conversion to open reduction, regardless of injury characteristics or previous reduction attempts. This strategy is likely to limit unnecessary open surgery and related risks. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.

Intracapsular Chondroma Occurring in Metacarpophalangeal Joint of the Hand: A Rare Presentation.

Extraskeletal chondroma comprises synovial chondromatosis, intracapsular chondroma and soft tissue chondroma, its presentation in the hand, however, is very rare. A 42-year-old woman presented with a mass around right fourth metacarpophalangeal (MCP) joint. She had no pain or discomfort in activities. The radiographs showed soft tissue swelling, but no calcification or ossifying lesions. The magnetic resonance imaging (MRI) showed a lobulated juxta-cortical encircling mass existing around the fourth MCP joint. We did not suspect any cartilage-forming tumour in MRI. The mass was easily removed because there was no adhesion with surrounding tissues and the specimen had the appearance of a cartilage. The histological diagnosis was chondroma. Based on the tumour location and histological results, we diagnosed it as intracapsular chondroma. Although intracapsular chondroma is very rare-ly seen in the hands, it is important to consider an intracapsular chondroma when differentiating a tumour in the hand because it is difficult to diagnose one in an imaging examination. Level of Evidence: Level V (Therapeutic).

Metacarpophalangeal hyperextension in thumb basal joint osteoarthritis: Radiological study and implications for treatment.

We report a series of 95 consecutive patients operated on for total trapeziometacarpal joint replacement, screening for radiological characteristics to differentiating patients with and without preoperative MCP hyperextension. Loss of thumb column length and metacarpal head circularity on lateral view were quantified. Statistically, a combination of reduced length and circular metacarpal head was a determining factor for MCP hyperextension. We therefore believe it is essential to restore thumb column length in surgery for trapeziometacarpal osteoarthritis and to avoid trapeziectomy in patients with a circular head on lateral view. LEVEL OF EVIDENCE: III; prospective cohort study.

In Vivo Metacarpophalangeal Joint Kinematics After Silicone Implant Arthroplasty in Patients With Rheumatoid Arthritis.

PURPOSE: The aim of this study was to determine the potential mechanism of implant fracture using 3-dimensional motion analysis of patients with rheumatoid arthritis. METHODS: Active flexion motion in 9 hands (34 fingers) of 6 female patients with rheumatoid arthritis who previously underwent hinged silicone metacarpophalangeal joint arthroplasty was examined using 4-dimensional computed tomography. Positions of the proximal phalanges relative to the metacarpals were quantified using a surface registration method. The deformation of the silicone implant was classified in the sagittal plane in the maximum flexion frame. The longitudinal bone axis of the proximal phalanx and the helical axis of the proximal phalanx were evaluated in 3-dimensional coordinates based on the hinge of the silicone implant. RESULTS: Nineteen fingers were classified into group 1, in which the silicone implant moved volarly during flexion without buckling of the distal stem. Twelve fingers were classified into group 2, in which the distal stem of the silicone implant buckled. Three fingers were classified into group 3, in which the base of the distal stem had already fractured. Quantitatively, the longitudinal bone axes of the proximal phalanges were displaced from dorsal to volar in the middle stage of flexion and migrated in the proximal direction in the late phase of flexion. The helical axes of the proximal phalanges were located on the dorsal and proximal sides of the hinge, and these tended to move in the volar and proximal directions as the metacarpophalangeal joint flexed. CONCLUSIONS: Volar and proximal translation of the proximal phalange was observed on 4-dimensional computed tomography. CLINICAL RELEVANCE: Proximal displacement of the bone axis late in flexion appears to be a contributing factor inducing implant fractures, because the pistoning motion does not allow the implant to move in the proximal direction.

Prognostic factors and clinical features in metacarpophalangeal joint hyperextension after ligament reconstruction with trapeziectomy: A retrospective cohort study.

BACKGROUND: Management of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes. METHODS: We investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°-20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR). RESULTS: Overall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821). CONCLUSIONS: Postoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.

Shapes and Sizes of Common Silicone Metacarpophalangeal Arthroplasties: Clinical Implications.

Background: Silastic metacarpophalangeal joint (MCPJ) arthroplasty is a recognised treatment for painful finger arthritis. There are two commonly used, albeit different, designs; the Swanson and the NeuFlex©. Which design is optimal is unclear. The purpose of this study was to evaluate the radiological differences relative to the bones following implantation. Methods: We examined the radiological features of these implants up to 1 year of follow-up. We reviewed the postoperative radiographs of 42 patients with 113 MCPJ arthroplasties and assessed the implant body anatomical 'fit' relative to the widths of the cut metacarpals and proximal phalanges and resection lengths of the metacarpal heads. We also looked for potential axial implant rotation. Results: The Swanson implants were consistently and statistically significantly wider than the NeuFlex© implants and almost always overhung the margins of the native MCPJ. Four of 33 (12%) of the Swanson and 1 of 80 NeuFlex© implants had rotated axially, the difference was statistically significant. One NeuFlex© implant had fractured at its hinge. Conclusions: The appreciable difference in the positions of the implant bodies relative to the bones may be important. The overhang of the Swanson implants may confer some stability to the arthroplasty helping to resist lateral deviation forces, but concomitant ligament reconstruction may increase the risk of implant rotation which is likely to reduce the postoperative ranges of motion. Axial silastic implant rotation has not previously been reported. It may influence joint biomechanics; future implant designs should consider the risks of implant rotation. Level of Evidence: Level IV (Therapeutic).

Locking of the Metacarpophalangeal Joint of the Thumb Caused by Entrapment of the Radial Sesamoid Bone.

Locking of metacarpophalangeal (MCP) joints of the thumb may be a consequence of dorsal subluxation from hyperextension injury. The joint is locked in mild hyperextension and cannot flex actively or passively. We report four patients with locked MCP joint of the thumb due to radial sesamoid entrapment after hyperextension or forced flexion injury. All patients had a prominent radial condyle of the metacarpal bone. Three patients had a deformity of the longitudinal groove on which the sesamoid was overlaid. The radial sesamoid was entrapped proximal to the radial condyle which could result in limited extension and hinged flexion of the joint. Excision of the radial sesamoid could release the locked joint. The radial sesamoid should be assessed if the motion of the thumb MCP joint is limited after flexion or extension injury. Level of Evidence: Level V (Therapeutic).

Collateral Ligament Ruptures of the Thumb Metacarpophalangeal Joint A Review of 500 Surgical Cases.

A retrospective review was conducted of 500 consecutive patients who underwent surgery for complete collateral ligament ruptures of their thumb metacarpophalangeal (MP) joints comprising 362 ulnar collateral and 138 radial collateral ligaments. Complete rupture was confirmed in all cases at surgery. When surgery was carried out within 3 weeks of the injury, reinsertion of the ligament was pos- sible in 98% of cases. When surgery was performed after 3 weeks, reinsertion of the ligament was possible in 45% of ulnar and 68% of radial injuries. Reconstruction utilizing a free tendon graft was required for the other cases. All patients who had surgery within 3 weeks of their injuries regained stable, pain free thumbs. Surgery was less suc- cessful in patients who had surgery after 3 weeks and the failure rate was 5%. Surgery within 3 weeks of the injury permitted re-insertion of the ligament in almost all cases. We propose that avulsions treated within that period be referred to as "acute" injuries and those treated later as "chronic." Treatment of acute injuries is preferred because they rarely require reconstruction, and the results were better than when surgery was performed for chronic injuries. Repair of thumb MP collateral ligaments is predictably possible within 3 weeks of injury but less likely if surgery is delayed after that time period.

Thumb basal joint arthritis: New classification, diagnostic and therapeutic algorithm.

The assessment of thumb basal joint arthritis requires a radiographic evaluation and a classification of the lesions to guide the treatment choice. Arthritis of the thumb basal joint is not limited to trapeziometacarpal arthritis. The radiographic assessment must consider the scaphotrapeziotrapezoid joint, the entire carpus and the rest of the thumb column, in particular the metacarpophalangeal joint. There is currently no classification that captures all these items. This article reviews the existing classifications, proposes a new classification system that takes into account the entire thumb column and sets out the therapeutic options.

Dorsal Capsule Interpositional Arthroplasty of the Metacarpophalangeal Joint.

Background: Current recommendations for osteoarthritis of the metacarpophalangeal joint (MCPJ) are confined to implant arthroplasty to preserve joint motion and provide pain relief. This study documents the median 2-year results of a novel soft tissue arthroplasty technique that interposes the dorsal capsule. Methods: A retrospective review of 10 MCPJ dorsal capsule interposition arthroplasties in 8 patients was conducted. Physical evaluation assessed MCPJ range of motion (ROM), grip strength, and pain. Outcome tests used were the Michigan Hand Outcome Score, Visual Analog Scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH). Kellgren and Lawrence Classification assessed severity of MCPJ osteoarthritis on preoperative radiographs. Results: The mean follow-up was 29 months from surgery. Average VAS was 2/10 postoperatively and average postoperative ROM improved 7 degrees. Average postoperative grip strength of the surgical hand was 30 kg. The QuickDASH average score was 24. Average Michigan Hand Questionnaire final score was 70. Patients with Kellgren Grades 2 or 3 osteoarthritis had the best QuickDASH and Michigan Hand Outcome scores. All patients working before surgery returned to work. No patient required a second surgery. Conclusion: This technique of dorsal capsule interposition arthroplasty provides a viable surgical option for isolated degenerative or traumatic arthritis of the MCPJ at an average follow-up of 2 years. Pain relief was most reliably provided in patients with less severe radiograph findings. The advantages of this procedure include preservation of bony anatomy, collateral ligaments, and volar plate to not preclude later implant arthroplasty.

Sonographic assessment of cartilage damage at the metacarpal head in rheumatoid arthritis: qualitative versus quantitative methods.

OBJECTIVE: To test the validity of the OMERACT semi-quantitative score by comparing with a quantitative method in the US assessment of hyaline cartilage at the metacarpal head (MH) in patients with RA and healthy controls (HCs). METHODS: The hyaline cartilage from the second to fifth MHs of both hands was scanned. Hyaline cartilage was scored semi-quantitatively and quantitatively by measuring cartilage thickness and comparing with reference values. In RA patients, radiographic joint space narrowing (JSN) was scored on the same joints using the Simple Erosion Narrowing Score (SENS). RESULTS: A total of 408 MHs in 51 RA patients and 320 MHs in 40 HSs were evaluated. The OMERACT semi-quantitative score was quicker to perform than the quantitative method [6.0 min (s.d. 0.5) vs 8.0 (1.5); P < 0.01]. A significant correlation between the US scores (R = 0.68) and between the US scores and the JSN-SENS (R = 0.61 and R = 0.63 for the semi-quantitative and quantitative method, respectively) was found. The frequency of cartilage abnormalities was similar between the two US methods in RA patients (58.8% and 51.0% of RA patients for the semi-quantitative and quantitative method, respectively; P = 0.46), while the former revealed more abnormalities in HCs (27.5% and 7.5% of HCs; P = 0.02). CONCLUSION: The higher feasibility of the OMERACT semi-quantitative score suggests its use as a first-choice method in the evaluation of cartilage damage. However, despite its limits, the quantitative assessment of HCs, providing patient-tailored information with age- and sex-corrected cut-off values, may represent a valid supplement for optimizing the evaluation of cartilage damage in selected cases.

Cartilage Degeneration of the Metacarpal Condyle and Enthesopaties of The Collateral Ligaments of Equine Metacarpophalangeal Joint.

Articular degeneration can be characterized by fibrillation and eburnation of the articular layers of the metacarpophalangeal (MP) joint. Structural changes within the articular joint predispose the development of osteophytes, enthesophytes and, in many cases is associated with changes the collateral ligaments of the MP joint. The aim of the present study was to investigate the relationship between degenerative processes of the articular cartilage and the enthesopathies of collateral ligaments (superficial or deep portion) of the equine MP joint, using radiographic, ultrasonographic and anatomopathological exam, as well as establishing their sensitivity. Thirty equine forelimbs were selected from animals that died due to various clinical conditions with an average age of 5.7 years which came from a private clinic or sent to the Laboratory of Veterinary Pathology of UFSM. The specimens were placed in a hydraulic press and submitted to radiographic evaluation of the MP joint (lateromedial, flexed lateromedial, dorsopalmar, dorsolateral-palmaromedial oblique 450 and dorsomedial-palmarolateral oblique 450 projections). Transversal and longitudinal ultrasound images of the dorsal and collateral aspect of the MP joint were obtained using a Sonosite Edge machine with a 5 to 10 MHz linear transducer. Subsequently, the specimens were sent for gross and histopathological examination. A highly positive correlation (P value <.001) was observed between ultrasonographic and macroscopic techniques, showing a relationship between the cartilaginous degenerations of the MP joint and the medial and lateral LC enthesopathies.

Magnetic resonance imaging of diffusion characteristics following collagenase clostridium histolyticum injection in Dupuytren's contracture.

PurposeWe aimed to evaluate the extent of collagenase clostridium histolyticum (CCH) diffusion in Dupuytren's contracture (DC) for tissues outside of the contracture cord using Magnetic Resonance Imaging (MRI) immediately after CCH injection. Methods: 10 male patients aged 57-79 with DC of the metacarpophalangeal (MCP) joints were examined. Extension deficits were 10-60°(mean, 34.3) and 0-60°(mean, 26.6) in the MCP and proximal interphalangeal (PIP) joints, respectively. CCH injection was performed according to the standard method. MRI was performed within 15 min of CCH injection. Results: In all 10 cases, the extended area of high-intensity signal change outside of the cord was observed on short-T1 inversion recovery images (STIRs). Continuity from the insertion site was observed in the area of signal change involving the flexor tendon and neurovascular bundle. The signal change area spanned distally and proximally beyond the injection level. The signal change area expanded along the tendon sheath but no signal changes were observed inside the flexor tendon, suggesting the tendon sheath serves as a protective barrier from the CCH solution. After 1 week of injection, the mean decrease in contracture was 32.5°(94.7%) for the MCP joint and 19.8°(74.4%) for the PIP joint. In nine out of 10 cases, the extension deficit was within five degrees of full extension in the affected finger. There was no neurovascular injury or tendon rupture at 3 months of observation. Conclusions: MRI indicated the possible leakage of the drug outside of the cord during the early phase after administration, suggesting that CCH could persistently affect healthy tissues until CCH inactivates its enzyme process.

[Ulnar collateral ligament injury to the thumb].

Instability of the ulnar collateral ligament (UCL) is disabling and can occur at any age as an acute or chronic condition. A medical history and objective examination together with the radiological findings are sufficient to make the diagnosis in the majority of cases. Otherwise, an ultrasound or MRI scan should be considered for the acute and chronic injuries, respectively. The partial injuries are treated non-surgically with immobilisation of the metacarpophalangeal joint, while the complete ruptures require surgery, which is summarised in this review. Chronic UCL injuries with symptomatic osteoarthritis are treated with arthrodesis.