Neurologic recovery following laminectomy and tumor resection of a pediatric cervical synovial osteochondromatosis causing paralysis.

PURPOSE: To report the surgical outcome of synovial osteochondromatosis, a rare tumor of the cervical spine, in a 6-year-old boy. METHODS: A 6-year-old boy presented with muscle weakness in the right deltoid (2) and biceps (4) during a manual muscle test. Magnetic resonance imaging showed a 3 × 2 × 1.5 cm mass within the spinal canal at the C4-6 level, compressing the cervical spinal cord from the right side. Computed tomography revealed hyperintense areas within the tumor and ballooning of the right C4-5 and C5-6 facet joints. RESULTS: After a biopsy confirmed the absence of malignancy, a gross total resection was performed. The pathological diagnosis of synovial osteochondromatosis was established. Postoperatively, muscle weakness improved fully in the manual muscle test, and there were no neurological findings after 3 months. However, the patient is under careful follow-up owing to the detection of a regrowth site within the right C4-5 and C5-6 intervertebral foramen 2 years postoperatively. CONCLUSIONS: Synovial osteochondromatosis of the cervical spine in children is rare, and this is the first report of its regrowth after surgery. Synovial osteochondromatosis should be included in the differential diagnosis of pediatric cervical spine tumors.

Concomitant lipoma arborescens and synovial osteochondromatosis of the knee.

Intra-articular masses are not a rare finding in routine imaging. This is particularly true in patients with underlying joint diseases such as degenerative arthritis. Nevertheless, concomitant presentation is rather uncommon in imaging studies. The authors report an unusual concomitant lipoma arborescens and synovial osteochondromatosis (which has not previously been reported in the literature to the best of the authors' knowledge) in a man in his 60 s with a long-standing history of knee osteoarthritis. In this case presentation, we review the differential diagnosis for noninfectious synovial proliferative disorders presenting as intra-articular masses, their potential association with underlying joint pathology, and discuss the key imaging features and appropriate treatment.

Whole-body MRI in assessing malignant transformation in multiple hereditary exostoses and enchondromatosis: audit results and literature review.

OBJECTIVE: To analyze the results of annual screening using whole-body magnetic resonance imaging (WBMRI) in patients with multiple hereditary exostoses (MHE) and enchondromatosis (EC), and estimate the risk for transformation to chondrosarcoma (CS) in these disorders. MATERIALS AND METHODS: A total of 62 patients (57 with MHE and five with EC) screened during a mean follow-up period of 4.6 years (range, 1-10 years) using 253 WBMRIs (median four WBMRIs per patient, range, 1-10) were analyzed retrospectively. The time of WBMRIs was compared with dates for diagnosed CSs. A supplementary literature review was performed focusing on the risk of malignant transformation. RESULTS: Ten patients had CS before being enrolled in the screening program, nine with MHE and one with EC. Three asymptomatic CSs were detected by screening; one in a patient with EC and two in patients with MHE, one of whom had CS previously. During the screening period, there was no occurrence of CS not detected by WBMRI in the study group. Histopathologically, the CSs were predominantly grade 1 and were, except for in two patients, located at the truncus, proximal femur, and shoulder girdle. Based on the current material and literature review, the risk of CS seems to be in the range of 2-3.7% for MHE and up to 50% for EC patients. CONCLUSIONS: MRI may be used as a screening method detecting malignant transformation in MHE and EC patients, but the efficacy has to be confirmed in long-term follow-up studies including cost analysis.

Single-Bone Forearm as a Salvage Procedure in Recalcitrant Pediatric Forearm Pathologies.

PURPOSE: To report on the outcome of single-bone forearm reconstruction (SBFR) as a salvage procedure in pediatric forearm pathologies. METHODS: Twenty-eight forearms in 27 patients (median age, 9.6 years; range, 3.4-29.7 years) treated with SBFR at a pediatric referral center were included in the study. Records and radiographs were retrospectively analyzed. Median follow-up was 84 months (range, 24-261 months). The most common underlying condition was multiple hereditary exostoses (MHEs) (17 of 28), followed by brachial plexus birth injury (5 of 28), Ollier disease (2 of 28), congenital radial head dislocation (2 of 28), and others (2 of 28). RESULTS: By 4 months (range, 2-10 months) after surgery, 21 of 28 forearms had united. Median resting postoperative forearm rotation was 10° pronation (range, neutral to 25° pronation). Before surgery, pain was present in 23 of 28 forearms. At the latest follow-up, pain was present in 5 of 28 forearms. In three of the 5 forearms with residual pain, this was attributed to ulnohumeral degenerative changes that existed prior to SBFR. Following SBFR, elbow flexion-extension range was maintained. In the subgroup with MHEs, radial articular angle was maintained (median, 37°-30°) and carpal slip percentage improved significantly (median, 40%-12%). Complications occurred in 8 forearms: 3 cases of nonunion in older patients (age, 30, 20, and 14 years), 2 cases of traumatic juxtaimplant fractures following successful union, 1 case of infection, 1 case of compartment syndrome, and 1 case of persistent radiocapitellar impingement. All complications were successfully treated. When stratified by age, none of the patients in the younger group (16 forearms, age < 12 years) had nonunions or pain at latest follow-up. CONCLUSIONS: The SBFR is an old, but generally reliable, option as a single-stage salvage procedure for a number of recalcitrant pediatric forearm pathologies. Success rate may be higher in younger patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Osteochondromatosis (multiple cartilaginous exostoses) in an immature killer whale Orcinus orca.

An immature killer whale Orcinus orca found dead on the southeastern Brazilian coast had multiple bone proliferations: on the skull, vertebrae, hemal arches, and ribs. The bony formations were characterized as multiple osteochondromas, as defined by osteochondromatosis. The diagnosis was based on macroscopic and radiographic observations. These benign osseocartilaginous tumors affect young individuals and grow until skeletal maturity is achieved. Case reports of this condition, besides humans, include other mammals, with most reports for pets and domestic mammals such as cattle, and a report in a fossil canid (Hesperocyon) from the Oligocene. The etiology, diagnosis, developmental characteristics, and occurrence of osteochondromas are distinct among different species. This report describes the first case of multiple osteochondromas in a wild cetacean.

Mitigating Risk of Ankle Valgus From Ankle Osteochondroma Resection Using a Transfibular Approach: A Retrospective Study With Six Years of Follow-Up.

To prevent worsening of ankle valgus and functional repercussions, a distal inter-tibiofibular osteochondroma can be removed using a transfibular approach. We evaluated the difference between the preoperative and postoperative tibiotalar tilt at the last follow-up examination and the clinical and radiologic outcomes. We included 10 consecutive ankles that had undergone removal of an osteochondroma using a transfibular approach. The mean patient age was 10.6 years. One ankle was lost to follow-up. The mean postoperative follow-up duration was 5.9 years. The mean preoperative and postoperative tibiotalar tilt was 7.2° and 7.1°, respectively, with no significant difference. The mean postoperative American Orthopaedic Foot and Ankle Society score was 92.4. Tibiofibular synostosis developed in 7 cases. Osteochondroma recurred in 1 case. The transfibular approach stabilizes ankle valgus and is associated with good functional outcomes. However, it is an extensive procedure associated with postoperative synostosis and, thus, should be considered primarily when surgical access for an anterior approach is limited.

Multiple Skeletal Deformities in a Middle-Aged Man.

A 54-year-old man was seen in our endocrinology clinic with evidence of a limited range of motion in his left foot. He had a history of diabetes mellitus type 2 and atrial fibrillation. His family history included evidence of skeletal deformities in some of his relatives. This could imply the potential existence of a hereditary condition. It is worth noting that spontaneous mutations have been reported in some cases. A pertinent physical examination revealed a surgical scar on the patient's left knee, a hallux valgus deformity on his left foot with compromised joint function, and painless bony prominences on that same foot. The skeletal survey findings were consistent with multiple hereditary exostoses. Multiple osteochondromatosis (MO) is a rare genetic disorder associated with serious complications that may significantly affect the health related quality of life of anyone having the disorder. To prevent further complications, these patients require long-term follow-up with regular clinical and radiological examinations.

Pathology of articular cartilage and synovial membrane from elbow joints with and without degenerative joint disease in domestic cats.

The elbow joint is one of the feline appendicular joints most commonly and severely affected by degenerative joint disease. The macroscopic and histopathological lesions of the elbow joints of 30 adult cats were evaluated immediately after euthanasia. Macroscopic evidence of degenerative joint disease was found in 22 of 30 cats (39 elbow joints) (73.33% cats; 65% elbow joints), and macroscopic cartilage erosion ranged from mild fibrillation to complete ulceration of the hyaline cartilage with exposure of the subchondral bone. Distribution of the lesions in the cartilage indicated the presence of medial compartment joint disease (most severe lesions located in the medial coronoid process of the ulna and medial humeral epicondyle). Synovitis scores were mild overall and correlated only weakly with macroscopic cartilage damage. Intra-articular osteochondral fragments either free or attached to the synovium were found in 10 joints. Macroscopic or histologic evidence of a fragmented coronoid process was not found even in those cases with intra-articular osteochondral fragments. Lesions observed in these animals are most consistent with synovial osteochondromatosis secondary to degenerative joint disease. The pathogenesis for the medial compartmentalization of these lesions has not been established, but a fragmented medial coronoid process or osteochondritis dissecans does not appear to play a role.

Synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis: sonographic diagnosis.

Synovial osteochondromatosis is an idiopathic benign metaplasia of the synovial membrane rarely found in an extra-articular bursa. We describe the case of a 55-year-old woman with synovial osteochondromatosis in the subacromial bursa mimicking calcific tendinitis. Plain radiographs showed a radiopaque mass over the middle facet of the greater tuberosity, suggesting calcific tendinitis. Sonography, however, showed a loose body in the subacromial bursa, and no evidence of calcification inside the rotator cuff.

Ankle synovial chondromatosis: Clinical, radiological, and surgical findings: A case report.

Synovial chondromatosis is a rare benign condition defined by the presence of cartilaginous lesions in the synovium of joints, tendon sheaths, and bursae. It most typically affects large joints, such as the knee, hip, and shoulder, but it is also reported in smaller joints. Nonetheless, ankle involvement is relatively uncommon. A complete history and clinical, physical, and radiographic examinations are usually used to determine the diagnosis. Hence, we reported a case of a young patient with left ankle primary synovial chondromatosis who presented with a left ankle mass and chronic pain.

Management of Primary Synovial Osteochondromatosis in the Ankle Joint With a Combined Posterior-Anterior Arthroscopic Procedure: A Case Report.

Primary synovial osteochondromatosis (PSO), a seldom-seen synovial proliferative disease involving chondral metaplasia, presents a unique challenge when affecting the ankle joint. Controversy exists regarding whether a combined posterior-anterior approach with total synovectomy is necessary to avert recurrence or malignancy. An 18-year-old Caucasian male presented to the outpatient clinic with clinical and imaging findings indicative of a stage III PSO. The surgical intervention involved a combined posterior-anterior arthroscopic approach with the removal of multiple loose bodies and complete synovectomy, resulting in complete relief of symptoms without recurrence at the 12-month follow-up. Pathological examination confirmed the diagnosis. The management of PSO in the ankle joint using a combined posterior-anterior arthroscopic approach with complete synovectomy demonstrated effectiveness in this case. Regular follow-ups are essential for monitoring long-term outcomes and detecting potential recurrence or malignant transformation.

Pediatric Synovial Osteochondromatosis of the Knee with Leg Length Discrepancy: A Case Report.

Introduction: Synovial chondromatosis (SC) is very rare among children. We are aware of no reports of patients with SC accompanied by leg length discrepancy (LLD). Case Report: We describe a case of synovial osteochondromatosis of a 7-year-old boy complicated by LLD. We performed epiphysiodesis of the distal femur and arthroscopic resection of loose bodies and total synovectomy. Three years after surgery, LLD had been corrected and there was no sign of recurrence. Conclusion: Physicians should be aware of synovial osteochondromatosis complicated by LLD in childhood and take radiographs of the whole length of lower legs when this condition is suspected.

An unusual cause of inguinal swelling: Primary synovial osteochondromatosis.

Inguinal swelling should raise suspicion for hip joint osteochondromatosis. Early recognition, accurate diagnosis, and prompt surgical intervention are essential for optimizing patient outcomes.

Synovial Chondromatosis in a Young Athlete: A Report of a Rare Case.

Synovial chondromatosis is a rare and benign disorder that involves the synovial lining of joints, synovial sheaths and bursae. The synovial layer of the joint is affected by a metaplastic process which in turn converts it into cartilagenous tissue. Eventually, it gets dislodged and transformed into a loose body in the large joints. We report the case of a 24-year-old young athlete who presented with complaints of painful movements and restriction of joint movements associated with a growing deformity in the right knee joint. This case report aims to describe a rare synovial pathology that necessitated arthroscopic synovectomy and diagnostic arthroscopy to treat, particularly in younger individuals. The atypical feature, in this case, was metaplastic development from the peripheral joint capsule attached to the surrounding cartilage, which, to the extent that the authors are aware, has only been documented in one instance in the record. Magnetic resonance imaging (MRI) was performed which demonstrated evidence of the joint effusion, synovial hypertrophy and a loose calcific body just anterior of the distal femoral condyle causing pressure over the patellar tendon anteriorly as well as a hyper-dense cyst in the popliteal region. Treatment often requires partial or complete synovectomy with either an arthroscopic or open approach.

Primary synovial osteochondromatosis of the ankle: A case report and review of the literature.

Primary synovial osteochondromatosis of the ankle is a rare and benign disease of the young adult. It is characterized by the formation of multiple nodules of hyaline cartilage under the synovium. It is usually asymptomatic but can sometimes be revealed by pain or joint mobility disorders. X-rays and CT scans can easily diagnose calcified osteochondromas, but ultrasound and MRI can provide a quicker diagnosis by visualizing non-calcified foreign bodies. Surgery under arthroscopy remains the best therapeutic choice, however, this pathology still causes recurrence in less than 1/3 of cases.

Synovial Osteochondromatosis: Clinical Characteristics Unique to the Shoulder.

Background: Synovial osteochondromatosis (SOC) of the shoulder is a rare condition with unclear characteristics. This study evaluated the clinical features and postoperative functional outcomes of SOC of the shoulder that are distinct from SOC of other joints. Methods: The characteristics of 28 shoulders with SOC that underwent arthroscopy were retrospectively assessed. Ten shoulders (35.7%) had rotator cuff tears (RCTs) and underwent concomitant arthroscopic rotator cuff repair. The mean follow-up period was 83.6 months (range, 24-154 months). Demographic characteristics and loose bodies localized under arthroscopy were compared between cases with and without concomitant RCTs. Radiography, ultrasonography, or magnetic resonance imaging were performed preoperatively and postoperatively. Visual analog scale (VAS) scores for pain and satisfaction were evaluated for all cases, and functional scores were assessed in shoulders with concomitant RCTs. Results: The average age was 36.2 ± 15.6 years among patients without RCTs and 58.3 ± 7.2 years among patients with RCTs. Seven shoulders (7%) had osteoarthritis. Arthroscopy revealed loose bodies in multiple spaces, including the glenohumeral joint, subacromial (SA) space, and biceps tendon sheath. Overall, loose bodies were found in multiple spaces in 12 shoulders (42.9%). Loose bodies were found in the SA space only in 4 shoulders (22.2%) without RCTs and in 7 shoulders (70.0%) with RCTs. VAS for pain decreased significantly from 3.9 ± 2.3 to 1.1 ± 1.3 (p < 0.001). The functional scores increased significantly after arthroscopic management for patients with concurrent RCTs (all p < 0.05). Recurrence of SOC occurred in 3 of the 22 shoulders (13.6%) who underwent postoperative imaging, but no patient had a recurrent RCT. Conclusions: Pain relief and patient satisfaction were achieved via arthroscopic management. Unlike in other joints, loose bodies can occur simultaneously in several spaces in the shoulder, including the glenohumeral joint, SA space, and biceps tendon sheath. Early diagnosis of SOC of the SA space can help prevent osteoarthritis and RCT progression.

A Missed Case of Synovial Osteochondromatosis.

Synovial osteochondromatosis or synovial chondromatosis is a benign joint pathology characterized by the development of multiple cartilaginous nodules or loose bodies in the synovial membrane that typically arise in the larger joints of the body. It usually presents as joint pain and, as seen in the present case, can occasionally be missed. Diagnosis involves a combination of clinical evaluation, imaging studies, and histopathological evaluation (which is confirmatory). Treatment depends on the severity of the disease, symptoms, and the patient's social situation, and may include monitoring for asymptomatic cases, non-surgical management (pain medications and physical therapy), or surgical intervention. Surgical intervention may include arthroscopic removal of loose bodies, synovectomy, or reconstruction/replacement in severe situations. Prognosis has a direct relationship to how early the disease is diagnosed. Early intervention with appropriate management can help alleviate symptoms; however, if left unmanaged, it can lead to joint damage and osteoarthritis or very rarely, malignant transformation into chondrosarcoma. This report describes the case of a 62-year-old female with complaints of bilateral knee pain who was originally diagnosed with osteoarthritis based on clinical exam and X-rays. Two magnetic resonance imaging (MRI) scans were done three years apart, with synovial osteochondromatosis being on the differential after the second scan. A left knee major synovectomy was conducted after the second MRI reading, where rubbery masses of tissue along with loose fragments were removed. Fluid from the tissue masses was sent to culture and pathology for interpretation. Two weeks post the surgery, the patient's pain improved tremendously, with adequate ambulation independently. Histopathology came back positive for synovial osteochondromatosis. This case report highlights the importance of keeping this joint pathology on the differential when treating patients with joint pain and interpreting imaging.

Sacroiliac joint involvement in osteochondromatosis: identifying its prevalence and characteristics from cross-sectional imaging

PURPOSE: Apart from a few case reports, sacroiliac joint (SIJ) involvement in osteochondromatosis has not been studied. We aimed to determine the prevalence and characteristics of such involvement using cross-sectional imaging. METHODS: In this retrospective study, three observers (one junior radiologist and two musculoskeletal radiologists) independently reviewed computed tomography (CT) or magnetic resonance imaging (MRI) of patients in our database who had osteochondromatosis (≥2 osteochondromas across the skeleton) for SIJ involvement. The final decision was reached by the consensus of the two musculoskeletal radiologists in a later joint session. RESULTS: Of the 36 patients with osteochondromatosis in our database, 22 (61%) had cross-sectional imaging covering SIJs (14 females, 8 males; age range 7-66 years; mean age 23 years; 13 MRI, 9 CT). Of these, 16 (73%) had intra-articular osteochondromas. For identifying SIJ osteochondromas on cross-sectional imaging, interobserver agreement was substantial [κ = 0.67; 95% confidence interval (CI): 0.34, 1.00] between the musculoskeletal radiologists and moderate (κ = 0.59; 95% CI: 0.23, 0.94) between the junior radiologist and the final consensus decision of the two musculoskeletal radiologists. In the cohort with cross-sectional imaging, the anatomical variations of the accessory SIJ (n = 6, 27%) and iliosacral complex (n = 2, 9%) were identified in six different patients with (n = 2) and without (n = 4) sacroiliac osteochondromas. CONCLUSION: Cross-sectional imaging shows frequent (73%) SIJ involvement in osteochondromatosis, which, although a rare disorder, nevertheless needs to be considered in the differential diagnosis of such SIJ anatomical variants as the accessory SIJ and iliosacral complex. Differentiating these variants from osteochondromas is challenging in patients with osteochondromatosis.

Feline osteochondromatosis in a 12-year-old feline leukaemia virus-negative cat.

Feline osteochondromatosis is a spontaneous osteocartilaginous exostosis associated with feline leukaemia virus (FeLV) infection or due to a frameshift variant in the exostosin glycosyltransferase 1 (EXT1) gene. Osteochondromatosis was diagnosed in an indoor-only, 12-year-old, neutered female, Russian Blue cat. Radiographs revealed bilateral calcified proliferations in the elbow, costochondral and sternochondral joints, which distorted the normal skeletal structure. Grossly, the proliferated joints presented with consistent, rounded masses, causing complete ankylosis. The main histopathological finding was an osteocartilaginous proliferation composed of multiple irregular islands of well-differentiated hyaline cartilage surrounded and delimited by osteoid tissue. Immunohistochemistry of the osteochondromas, bone marrow and mediastinal lymph nodes, using a primary anti-FeLV gp70 antibody, and FeLV proviral DNA real-time polymerase chain reaction on bone marrow were negative. Sequencing of exon 6 of the EXT1 gene was performed and nucleotide BLAST analysis demonstrated the absence of a frameshift variant. This study reports the only case of spontaneous feline osteochondromatosis in an animal more than 10 years old.

Synovial Chondromatosis in a Rural Healthcare Setting.

Synovial chondromatosis is a rare, benign, and metaplastic cause of joint swelling resulting in the formation of cartilaginous nodules in the joint space. It is usually an oligoarticular disorder of large joints that typically manifests in the third to fifth decade of life. Synovial chondromatosis can be primary or secondary depending on whether an underlying etiology can be identified. Diagnosis can be made using imaging studies of the affected joint and confirmed on histopathology. Management of synovial chondromatosis can be done arthroscopically or surgically. We present a case of a 23-year-old male who presented with a long history of right knee pain, swelling, and limitation in range of motion. An X-ray of the knee showed multiple intra-articular and soft tissue calcifications. Due to the limitations of our setting, we proceeded with an open biopsy. During arthrotomy, clear straw-colored fluid with multiple nodules of varied sizes was found. A google image search helped put us in the direction of the diagnosis of synovial chondromatosis. We did a complete evacuation of loose bodies and a biopsy of synovium, which confirmed the diagnosis. The rarity of synovial chondromatosis results in a delay in the diagnosis. With the thoughtful application of resources and surgical principles, synovial chondromatosis can be safely and effectively managed in resource-limited settings.