Carpal Boss: A Case Series of a Radiological Enigma in Dorsal Wrist Pathology.

Carpal boss, a relatively rare and often underdiagnosed condition, is characterized by a bony protuberance at the dorsal aspect of the carpometacarpal (CMC) joint. It is commonly misdiagnosed due to its nonspecific clinical presentation, which can mimic other conditions, such as ganglion cysts or fractures. This case series aims to document and analyze the clinical presentations and radiological findings of three patients diagnosed with carpal boss, highlighting the importance of advanced imaging techniques in accurate diagnosis and management. A case series was conducted at Tenet Diagnostics, Bengaluru, Karnataka, involving three patients with dorsal wrist pain and swelling at the CMC joint. All patients underwent clinical evaluation followed by imaging studies using 3T magnetic resonance imaging (MRI) (United Imaging, Shanghai, China) and 32-slice computed tomography (CT) (Siemens Somatom Go; Siemens Healthineers, Munich, Germany). The MRI sequences included T1-weighted and proton density (PD) fat-saturated images, while CT imaging focused on axial and sagittal sections to assess bony structures. All three patients were diagnosed with carpal boss based on imaging findings. MRI revealed hypertrophied bony protuberances at the bases of the second and third metacarpal bones, forming pseudoarthrosis with associated osteoarthritic changes. CT imaging confirmed these findings, providing high-resolution views of the bony abnormalities. Combining MRI and CT was crucial in differentiating carpal boss from other potential diagnoses, such as ganglion cysts or fractures. This case series underscores the importance of advanced imaging modalities, such as MRI and CT, in diagnosing carpal boss. Accurate and early diagnosis can prevent mismanagement and guide appropriate treatment strategies, improving patient outcomes. Increased awareness of carpal boss among clinicians and radiologists is essential for promptly recognizing and managing this condition.

High-resolution ultrasound approach to quadrangular joint in carpal boss: Everything musculoskeletal sonographer should know.

At the quadrangular joint (QAJ) of the carpus, a rare bony protuberance called carpal boss (CB) may occur. This bone abnormality may be due to osteophytes development or os styloideum. Symptomatic patients may complain pain, swelling, and restrictions in hand motion. These symptoms result from joint degenerative-inflammatory changes, development of ganglion cyst/bursitis, or tendons pathology. Correct diagnosis and appropriate management can be achieved through high-resolution ultrasonography (HR-US). The purpose of this review is to define the pathology spectrum around and within the QAJ in CB. The role of HR-US is highlighted and the standard technique for the QAJ assessment is described.

A rare case of carpal boss lesion with an overlying ganglion cyst: case report and literature review.

Carpal boss is a bony protrusion on the dorsal aspect of wrist quadrangular joint. The exact cause and prevalence are not well understood. Most of the patients are asymptomatic, although some experience pain, bony prominence, restricted mobility, and joint instability in sever neglected cases. We are presenting a case of a 24-year-old male had chronic dorsal wrist pain with bony prominence appearance underwent surgical excision of a carpal boss lesion in concomitant with soft tissue ganglion cyst over the carpal boss after failed conservative management, resulting in significant symptom improvement and restored range of motion. Carpal boss lesion is a common condition that can be undiagnosed due to asymptomatic presentation or the presence of overlying soft tissue pathology as ganglion cyst. Although conservative treatment is helpful in some patients, most symptomatic carpal boss lesion patients eventually need surgical excision.

Recurrence rate and patient-reported outcomes after wedge excision of carpal boss.

The treatment of carpal boss is primarily conservative. Surgical treatment by performing a wedge excision of the bony protrusion, is possible. However, a common belief exists that carpal boss should not be operated because of the high recurrence rate. Additionally, little is known about the clinical outcomes of wedge excision and the preferred post-operative treatment. Patients with carpal boss and persisting pain who underwent wedge excision after conservative treatment were included. They received questionnaires before and three months after surgery. The primary outcomes were pain and hand function measured using patient-reported wrist evaluations (PRWE). Secondarily, recurrence, patient satisfaction and time until return to work were evaluated. These clinical outcomes were also compared between patients who received a plaster splint or a pressure dressing post-operatively. 76 patients were included. Three months after surgery, a significant improvement in PRWE was seen, for both pain and function. A re-operation rate for recurrent carpal boss of 13% was observed. After three months, 58% of patients were satisfied and 73% had returned to work. While no differences in clinical outcomes were found, patients were more satisfied after receiving a pressure dressing than a plaster splint post-operatively. The current study demonstrates encouraging early outcomes after wedge excision, and a low recurrence re-operation rate. Furthermore, a pressure dressing seems preferable post-operatively compared to a plaster splint.

Dorsal Wrist Carpal Boss Impingement-Dynamic Ultrasound to the Rescue!

The "carpal boss" is a variant present in 19% of the population according to cadaveric studies but becomes symptomatic in only 1% of cases. With the rising popularity of "yoga," which includes prolonged hyperextension at the wrist joint with weight bearing, an increasing number of individuals with silent carpal boss present with dorsal wrist pain due to impingement over the dorsal soft tissues by this innocuous bony protuberance. This warrants the attention of radiologists and clinicians while dealing with wrist pain. It can be challenging to identify this bossing on routine radiographs, necessitating special views. We describe the use of dynamic ultrasound in diagnosing "symptomatic" carpal boss, the effects of which become even more evident on imaging during hyperextension-the triggering movement.

Surgical treatment for persistent second carpometacarpal joint pain.

The purposes of this study were to demonstrate the clinical characteristics of patients with persistent second carpometacarpal (CMC) joint pain without bony abnormalities known as the carpal boss, and to assess the clinical efficacy of surgical stabilization of the second CMC joint. Eleven patients had persistent wrist pain with characteristic symptoms, including tenderness over the second CMC joint, increased symptoms when the involved hand was placed on the ground or gripped strongly with the involved hand, a positive metacarpal stress test and temporary pain relief with the intra-articular injection of the lidocaine. The patients underwent arthrodesis of the second CMC joint. All cases showed radiologically confirmed fusion of the second CMC joint. At the final followup examination, 10 of 11 patients resulted in satisfactory clinical outcomes, excepting one patient with remnant pain and restricted range of wrist motions. This report highlights the importance of conducting a careful assessment of patients who present with persistent second CMC joint pain without the bony abnormalities, such as carpal bossing. Surgery to stabilize the second CMC joint may be an option to improve their symptoms when conservative treatment fails.

MRI of a painful carpal boss: variations at the extensor carpi radialis brevis insertion and imaging findings in regional traumatic and overuse injuries.

OBJECTIVE: To report patterns of MRI findings involving carpal boss and extensor carpi radialis brevis (ECRB) tendon insertion in individuals with overuse-related or post-traumatic wrist pain. MATERIALS AND METHODS: Eighty-four MRI cases with carpal bossing between December 2006 and June 2015 were analyzed by two fellowship-trained musculoskeletal radiologists. The following MRI findings were reviewed: type of carpal bossing (bony prominence, partial coalition, os styloideum), insertion of ECRB tendon (to the 3rd metacarpal, to carpal boss or to both), bone marrow edema (BME), insertion site, and tenosynovitis/tendinosis of ECRB tendon. Clinical information on wrist pain was available on 68 patients. RESULTS: Fused carpal bossing was detected in 21%, partial coalition in 35%, and os styloideum in 44% of the cases. Regional BME was observed in 64% of the cases. When BME specifically at the carpal boss was assessed, 78% of stable and 50% of unstable bosses showed BME (p = 0.035). ECRB tendon inserted on a carpal boss in 20%, on the 3rd metacarpal bone in 35%, and on both sites in 45% of the cases. As BME at the carpal boss was assessed, BME was detected at the respective insertion sites in 71%, 35%, and 66% of the cases (p = 0.015). Dorsal wrist pain was associated with BME as 75% of the patients had regional BME in the vicinity of the carpal boss (p = 0.006). CONCLUSION: A spectrum ranging from complete fusion of a boss to an entirely unfused os styloideum exists with a variable ECRB insertional anatomy. BME at the carpal boss is a consistent MRI finding.

The Fourth Extensor Compartment Artery Vascularized Bone Graft of the Distal Radius for CMC Fusion in the Treatment of Carpal Boss: A Case Report.

BACKGROUND: Carpometacarpal joints can be affected by traumatic or degenerative pathology. Although different techniques have been described to treat these conditions, most authors agree that arthrodesis is an effective treatment modality. Vascularized bone grafts of the distal radius have been used to treat carpal conditions, such as scaphoid nonunion or Kiënbock disease, and they have been shown to have several advantages over nonvascularized bone grafts. METHODS: We report a case of a carpal boss in a female patient treated with an arthrodesis of the second and third carpometacarpal joints by using the fourth extensor compartment artery vascularized bone graft. RESULTS: At 6 weeks postoperative bone union was achieved. At 2 years follow-up the patient was able to perform daily life activities without pain. CONCLUSIONS: The fourth ECA VBG with reverse blood flow from the dorsal intercarpal arch allowed the graft to reach the CMC. A solid fusion was obtained at 6 weeks due to the biological advantage of the VBG.

Surgical treatment of carpal boss by simple resection: Results in 25 cases at a mean of 8 years' follow-up.

Carpal boss is a symptomatic bony protrusion on the dorsal surface of the wrist at the base of the 2nd and/or 3rd metacarpal. The goal of this study was to assess the reliability and safety of simply resecting the exostosis. From 1994 to 2014, 29 cases of carpal boss were treated by simple resection. Twenty-five of these patients were subsequently assessed by telephone questionnaire at a mean of 8 years' follow-up (range 1.1 to 20 years). There were no cases of recurrence; however, 1 patient reported carpometacarpal instability requiring fusion, 5 years after surgery. Eight of the 24 patients without fusion (33%) reported moderate episodic pain (visual analog scale [VAS] pain: mean, 2.3/10, range 1 to 4). Range of motion improved in 8 cases (33%), was unchanged in 11 (46%) and decreased in 5 (21%). Twenty patients (83%) had no functional impairment; 4 reported impairment during unusual hand movements. Fifteen patients considered themselves cured (60%), 9 considered their status improved (36%) and one - the patient who required fusion - considered his status unchanged. Patients were very satisfied with the procedure in 15 cases (60%) and satisfied in 10 (40%). In all cases, features of dysplasia were present and associated with secondary osteoarthritis limited to the area of impingement. The single failure was most likely due to excessive bone resection. Simple exostosis resection is sufficient to effectively treat carpal boss. Fusion should be reserved for the rare cases of secondary metacarpal instability.

MRI diagnosis of carpal boss and comparison with radiography.

Background A carpal boss is a potentially painful bony mass in the region of the second or third carpometacarpal joint. The combination of clinical examination and radiography is usually sufficient for the diagnosis. Purpose To determine whether magnetic resonance imaging (MRI) examination of the quadrangular joint can assist the diagnosis of persistent pain near a carpal boss. Material and Methods Fifty-seven patients with a carpal boss were retrospectively reviewed using MRI and conventional radiographs and compared to an asymptomatic control group. Results MRI demonstrated a variable morphology and a variety of bone and soft tissue abnormalities associated with carpal boss. Bone marrow edema around the quadrangular joint shows a significant correlation (Fisher's exact test: P < 0.001) and a positive correlation (Pearson's test r = 0.632, significant at the 0.01 level [two-tailed]) with a painful carpal boss. Conclusion MRI offers detailed examination of bone and soft tissue abnormalities associated with a carpal boss. Local bone marrow edema strongly correlates with a painful carpal boss.

Characterization and Epidemiology of the Carpal Boss Utilizing Computed Tomography.

Background The carpal boss is an osseous protuberance occurring variably along the dorsum of the second or third metacarpal base, lacking a standardized definition. Aim We sought to characterize the dorsal second and third carpometacarpal joints in the general population on computed tomography (CT) to better define this variant anatomy. Patients and Methods A total of 129 wrist CT studies were reviewed. Note was made of the dorsal second/third carpometacarpal osseous anatomy, the presence of regional bursitis or tenosynovitis, and relationship of the extensor carpi radialis brevis attachment to the base of the third metacarpal. Results Out of the 129 wrists, 106 (82.2%) demonstrated a dorsal protuberance arising from the base of the third metacarpal, in isolation. Out of the 129 wrists, 14 (10.9%) lacked a dorsal protuberance or nonunited ossicle at the level of the second or third carpometacarpal joint. Out of the 129 wrists, 9 (7%) wrists demonstrated more complex anatomy-8 wrists (6.2%) with a dorsal protuberance at the base of the third metacarpal seen in combination with an adjacent nonunited ossicle and/or dorsal protuberance arising from the capitate, and 1 wrist (0.8%) with an isolated ossicle at the base of the third metacarpal. Of these nine wrists, eight (6.2%) demonstrated arthritis at the resultant pseudoarticulation(s). Conclusion The majority of wrists demonstrated an isolated protuberance arising from the dorsal base of the third metacarpal, with a small minority with a nonunited ossicle at this level and/or dorsal protuberance of the capitate. The presence of secondary arthritis (8 out of 129 wrists, 6.2%) may reflect a pain generator. Level of Evidence Cross-sectional study; level 2.

That's my STYLEoideum - Symptomatic os styloideum in an adolescent male.

We present a 15-year-old male patient with persistent localized pain on the dorsal side of the left wrist between the base of the 2nd and 3rd metacarpal bones and over the third carpometacarpal joint. It was diagnosed as an accessory metacarpal bone -Os styloideum. This entity may be detected on plain radiographs and in ultrasound examination and is often asymptomatic. Symptomatic os styloideum occurs more frequently in the dominant hand and may be treated conservatively with corticosteroid infiltration. A palpable prominence on the dorsal side of the wrist and focal pain evoked anxiety of the adolescent patient who searched medical consultation. In the clinical examination, a bony protrusion was confirmed and different possible diagnoses have been considered. After treatment with a corticosteroid infiltration of the third carpometacarpal joint under fluoroscopy the pain resolved completely. We would like to draw attention of clinicians and radiologists to this rare anatomical variant that normally is asymptomatic, and therefore not immediately recognized. Acquaintance with this entity and its early detection may lead to conservative treatment instead of surgical excision. A comprehensive literature search, review and discussion about os styloideum are provided in the article.

Imaging Findings at the Quadrangular Joint in Carpal Boss.

A carpal boss was initially described as a bony, sometimes painful mass at the quadrangular joint. Clinical examination and plain radiography will usually reveal the diagnosis. US and CT may add information. MRI may illustrate a variable bony morphology and additional bony and soft tissue pathologies. Bone marrow edema shows a significant correlation with a painful carpal boss. Hence, MRI may be of additional diagnostic value in patients with persistent pain and preoperatively. This paper presents a review of the anatomy and pathology in carpal boss. The merit of each imaging modality - in particular MRI - is mentioned.

Carpal boss in chronic wrist pain and its association with partial osseous coalition and osteoarthritis - A case report with focus on MRI findings.

The carpal boss is a bony prominence at the dorsal aspect of the 2(nd) and/or 3(rd) carpometacarpal joint, which has been linked to various etiologies, including trauma, os styloideum, osteophyte formation, and partial osseous coalition. It may result in symptoms through secondary degeneration, ganglion formation, bursitis, or extensor tendon abnormalities by altered biomechanics of wrist motion. We present a case of symptomatic carpal boss with the finding of a partial osseous coalition at the 2(nd) carpometacarpal (metacarpal-trapezoid) joint and highlight the magnetic resonance imaging (MRI) findings of carpal boss impingement and secondary osteoarthritis. To the best of our knowledge, there is no report in the literature describing the imaging findings of partial osseous coalition and degenerative osteoarthritis in relation to carpal boss.

The value of SPECT/CT in carpal boss.

PURPOSE: To assess the value of SPECT/CT in patients with carpal boss (CB). METHODS: In 24 wrists with CB (18 right-sided, 6 left-sided) in 21 patients, planar images and SPECT/CT images were obtained. Three patients had bilateral CB. The grade of uptake (0 absent, 1 low, 2 moderate, 3 high) on planar imaging and SPECT/CT was assessed and compared with CT findings, clinical symptoms and follow-up findings. RESULTS: CB affected carpometacarpal joint II in 4 wrists, carpometacarpal joint III in 17 wrists and both carpometacarpal joints II and III in 3 wrists. Of the 24 CB, 12 (50 %) were active (i.e. increased radionuclide uptake) on planar images and 18 (75 %) on SPECT/CT images. Of the 17 symptomatic CB, 10 (59 %) were active on planar images and 14 (82 %) were active (mean grade 1.9, range 1 - 3) on SPECT/CT images. Of the 7 asymptomatic CB, 2 were active on planar images and 4 were active (mean grade 1.25, range 1 - 2) on SPECT/CT images. CT alone showed CB in all patients and an accessory ossicle (os styloideum) in 8 wrists. MR imaging was available in 7 patients and positive for CB in 5 (sensitivity 71 %). Plain radiographs were available in 17 patients and positive in 10 (59 %). Therapeutic infiltration of the CB was performed in 9 patients, and resection of the CB in 7 patients. CONCLUSION: SPECT/CT provides important morphological and metabolic information for the clinical assessment of CB, but because SPECT/CT tends to overestimate the clinical importance of CB, we recommend that planar images should still be obtained.

The carpal boss: a review of different sonographic findings / Revisão sobre as diferentes apresentações da bossa carpal na ultrassonografia

Carpal boss is an uncommon condition whose incidence is underestimated and that is frequently confused with other causes of development of tumor-like lesions on the dorsum of the wrist. From the clinical point of view, the main obstacle to its recognition is the nonspecificity of symptoms, frequently attributed to dorsal ganglion cysts, since both conditions share a similar location on the dorsum of the wrist. The assessment by ultrasonography allows for a correct diagnosis and appropriate management, with better chances of resolution of the clinical complaint and lower probability of iatrogenic worsening of the lesion. The present review is aimed at describing the different sonographic findings of carpal boss.

A bossa carpal é uma enfermidade incomum, porém de incidência subestimada, frequentemente confundida com outras causas de tumoração no carpo dorsal. Do ponto de vista clínico, o principal obstáculo ao seu reconhecimento reside na inespecificidade dos sintomas, frequentemente atribuídos a cistos dorsais, já que ambos compartilham localização muito semelhante no carpo. A avaliação por ultrassonografia permite diagnóstico correto e manejo específico, que resulta em melhores chances de resolução da queixa clínica e menor probabilidade de piora iatrogênica da lesão. O objetivo deste artigo é revisar as diferentes apresentações ultrassonográficas da bossa carpal.

Attrition or rupture of digital extensor tendons due to carpal boss: report of 2 cases.

We present 2 cases that demonstrate the potential for tendon involvement in the presence of a carpal boss. In the first, a patient presented with tendon rupture without antecedent pain. In the second, pain and tendon irritation prompted magnetic resonance imaging that revealed tendon fraying, which was confirmed at surgery. These cases illustrate the potential for tendinous sequelae of a carpal boss. Advanced imaging may be considered when tendon irritation is clinically suspected. Attention to the possibility of tendon rupture in the setting of an otherwise asymptomatic carpal boss is advised.

The carpal boss: a review of different sonographic findings.

Carpal boss is an uncommon condition whose incidence is underestimated and that is frequently confused with other causes of development of tumor-like lesions on the dorsum of the wrist. From the clinical point of view, the main obstacle to its recognition is the nonspecificity of symptoms, frequently attributed to dorsal ganglion cysts, since both conditions share a similar location on the dorsum of the wrist. The assessment by ultrasonography allows for a correct diagnosis and appropriate management, with better chances of resolution of the clinical complaint and lower probability of iatrogenic worsening of the lesion. The present review is aimed at describing the different sonographic findings of carpal boss.

A bossa carpal é uma enfermidade incomum, porém de incidência subestimada, frequentemente confundida com outras causas de tumoração no carpo dorsal. Do ponto de vista clínico, o principal obstáculo ao seu reconhecimento reside na inespecificidade dos sintomas, frequentemente atribuídos a cistos dorsais, já que ambos compartilham localização muito semelhante no carpo. A avaliação por ultrassonografia permite diagnóstico correto e manejo específico, que resulta em melhores chances de resolução da queixa clínica e menor probabilidade de piora iatrogênica da lesão. O objetivo deste artigo é revisar as diferentes apresentações ultrassonográficas da bossa carpal.

The Operative Treatment for Carpal Boss / 대한정형외과학회잡지

PURPOSE: Carpal boss of the hand is a rare lesion. This study was conducted to recognize the clinical patterns of this disease entity and to evaluate the diagnosing modalities, differencial diagnosis, and results after operative treatment. MATERIALS AND METHODS: We report upon 7 operative cases of carpal boss of the hand. There were 5 females and 2 males with an aver-age age of 35.4. The mean follow up period for patients in this study was 15 months. The dominant hand was affected in 4 cases and the small ganglion was associated with the carpal boss in 4 cases. RESULTS: The average duration of conservative treatment before surgical treatment was 8.3 months. All of the patients had taken NSAIDs prior to surgery and 4 patients had received a corticosteroid injection at least once. All of the patient had surgical treatment and complete symptomatic relief was achieved in 6 cases. One patient had no symptomatic relief. CONCLUSION: We operated upon patients who did not respond to conservative treatment or in whom the carpal boss associated with a ganglion, 5 of 7 cases showed a satisfactory result. In view of these results, we recommended that operative treatment should be con-sidered in such cases.