This study aimed to delineate the detailed anatomy of the metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints in healthy horses using cone beam computed tomography (CBCT). The fetlock region of 15 cadaveric forelimbs and 14 cadaveric hindlimbs from nine adult horses without orthopaedic disease underwent CBCT scanning. Additionally, arthrography CBCT scans were conducted following intra-articular injection of a radiopaque contrast medium containing blue epoxy resin dye. Subsequently, limbs were frozen and sectioned to visualize anatomical structures in sectional planes corresponding to selected CBCT images. CBCT proved suitable for detailed visualization of the bony components of the fetlock region. Furthermore, the common digital extensor tendon, superficial and deep digital flexor tendons, suspensory ligament, and straight and oblique sesamoidean ligaments were identifiable on CBCT images. However, certain ligaments, such as the collateral sesamoidean ligaments and intersesamoidean ligaments, were not clearly identified. The hyaline cartilage of the MCP and MTP joint facets was assessable on the post-contrast sequence. In cases where a radiographic or ultrasound examination cannot provide a definitive diagnosis and determine the extent of disease, CBCT can provide additional valuable data on the equine MCP and MTP joint. The images obtained in this study can serve as a reference for CBCT examination of the equine MCP and MTP joint.

Lumbrical muscles originate on the flexor digitorum profundus (FDP) tendons and, during fist making, they move in the same direction when FDP muscle produces maximal proximal tendon gliding. Injuries of the bipennate lumbricals have been described when a shear force acts between the origins on adjacent tendons of the FDP, as they glide in opposite directions in asymmetric hand postures. Other structures of the deep flexors complex can be affected during this injury mechanism, due to the so-called quadriga effect, which can commonly occur during sport climbing practise. Biomechanical studies are needed to better understand the pathomechanism. A cadaveric study was designed to analyse the effects of load during the fourth lumbrical muscle injury mechanism. The amount of FDP tendon gliding and metacarpophalangeal (MCP) joint flexion of the 5th finger were calculated. Ten fresh-frozen cadaveric specimens (ten non-paired forearms and hands) were used. The specimens were placed on a custom-made loading apparatus. The FDP of the 5th finger was loaded, inducing isolated flexion of the 5th finger, until rupture. The rupture occurred in all specimens, under a load of 11 kg (SD 4.94), at 9.23 mm of proximal tendon gliding (SD 3.55) and at 21.4° (SD 28.91) of MCP joint flexion. Lumbrical muscle detachment from the 4th FDP was observed, from distal to proximal, and changes in FDP tendons at the distal forearm level too. The quadriga effect can lead to injury of the bipennate lumbrical muscles and the deep flexors complex in the hand and forearm.

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.

BACKGROUND: metacarpophalangeal dislocations of the thumb are not very frequent injuries, it is necessary to know the anatomy of the region to know possible causes of interposition that prevent a closed reduction of this pathology.
METHODS: we present the case of a 75-year-old woman with a post-traumatic metacarpophalangeal dislocation of the thumb that required open reduction and surgical repair. In this procedure, we performed reduction of the dislocation, mobilization of the interposed structures, repair of the capsule and reinsertion of the ulnar collateral ligament. The early mobilization protocol helped to obtain very good results.
CONCLUSIONS: it is imperative to consider possible associated injuries during the acute phase to achieve optimal short, medium, and long-term outcomes for our patients. A comprehensive and proactive approach to diagnosis and treatment is vital in effectively addressing this pathology and minimizing its potential sequelae.
UNASSIGNED: las luxaciones metacarpofalángicas del pulgar no son lesiones muy frecuentes, es necesario conocer la anatomía de la región para conocer posibles causas de interposición que impidan una reducción cerrada de esta patología.
UNASSIGNED: presentamos el caso de una mujer de 75 años con luxación metacarpofalángica postraumática del pulgar que requirió reducción abierta y reparación quirúrgica. En este procedimiento realizamos reducción de la luxación, movilización de las estructuras interpuestas, reparación de la cápsula y reinserción del ligamento colateral cubital. El protocolo de movilización temprana ayudó a obtener muy buenos resultados.
UNASSIGNED: es imperativo considerar posibles lesiones asociadas durante la fase aguda para lograr resultados óptimos a corto, mediano y largo plazo para nuestros pacientes. Un enfoque integral y proactivo del diagnóstico y tratamiento es vital para abordar eficazmente esta patología y minimizar sus posibles secuelas.

BACKGROUND: 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.
METHODS: 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.
CONCLUSIONS: 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.
CONCLUSIONS: 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.

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.

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).

While ultrasound and MRI are both superior to clinical examination in the detection of joint inflammation, there is presently a lack of data whether thermography may be similarly useful in the assessment of joint inflammation in patients with RA. Our study aims to evaluate the use of thermography in detecting subclinical joint inflammation at clinically quiescent (non-tender and non-swollen) metacarpophalangeal joints (MCPJs) in patients with rheumatoid arthritis (RA). The outcomes from thermography in our study will be compared with ultrasonography (which is a more established imaging tool used for joint inflammation assessment in RA).
The minimum (Tmin), average (Tavg) and maximum (Tmax) temperatures at the 10 MCPJs of each patient were summed to obtain the Total Tmin, Total Tavg and Total Tmax, respectively. Ultrasound grey-scale (GS) and power Doppler (PD) joint inflammation (scored semi-quantitatively, 0-3) at the 10 MCPJs were summed up to derive the respective TGS and TPD scores per patient. Pearson\'s correlation and simple linear regression were respectively used to assess correlation and characterize relationships between thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TGS, TPD and the number of joint(s) with PD ≥ 1 or GS ≥ 2).
In this cross-sectional study, 420 clinically non-swollen and non-tender MCPJs from 42 RA patients were examined. All thermographic parameters (Total Tmin, Total Tavg and Total Tmax) correlated significantly (P-values ranging from 0.001 to 0.0012) with TGS score (correlation coefficient ranging from 0.421 to 0.430), TPD score (correlation coefficient ranging from 0.383 to 0.424), and the number of joint(s) with PD ≥ 1 or GS ≥ 2 (correlation coefficient ranging from 0.447 to 0.465). Similarly, simple linear regression demonstrated a statistically significant relationship (P-values ranging from 0.001 to 0.005) between all thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TPD and TGS).
For the first time, thermographic temperatures were shown to correlate with ultrasound-detected joint inflammation at clinically quiescent MCPJs. The use of thermography in the detection of subclinical joint inflammation in RA appears promising and warrants further investigation.

UNASSIGNED: Peveler, WW, Schoffstall, J, Coots, J, Kilian, J, and Glauser, J. The effects of boxing glove design on thumb position when making a fist for striking. J Strength Cond Res 38(5): 948-950, 2024-It has been suggested that boxing glove design alters thumb position increasing the risk of injury. The purpose of this study was to determine the effects of boxing glove design on thumb joint angles when making a fist. Ten experienced fighters participated in this study. A DEXA scan was used to produce an x-ray image of thumb position for all conditions (no gloves and 10-oz boxing gloves). Mean values for dependent measures were compared using a paired-sample T test and an alpha of 0.05. The carpometacarpal (CMC) joint angle was significantly different between no glove (14.1 ± 6.54°) and boxing glove (34.2 ± 7.60°) at p ≤ 0.001. The metacarpophalangeal (MP) joint angle was significantly different between no glove (132.6 ± 12.74°) and boxing glove (149.40 ± 8.15°) at p ≤ 0.001. The IP joint angle was not significantly different between no glove (135.50 ± 19.12°) and boxing glove (144.40 ± 17.39°) at p = 0.269. The perpendicular distance from the second metacarpal of the hand to the center of the MP joint was significantly different between no glove (0.48 ± 0.54 cm) and boxing glove (1.84 ± 0.29 cm) at p ≤ 0.001. Use of a boxing glove resulted in abduction of the thumb away from the hand and increased CMC and MP joint angles that were significantly different in relation to making a fist without a glove. Information from this study may provide insight into the high rate of thumb injury and provide insight for future boxing glove design.

OBJECTIVE: 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.
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.
CONCLUSIONS: 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.
METHODS: Therapeutic study, level IV.