Synovial haemangioma of the knee joint: an unusual cause of knee pain in a 14-month old girl

MRI features of subcutaneous anterior knee mass associated with a focal defect of the patellar retinaculum

OBJECTIVE

The purpose of this study was to assess the frequency and MRI features of a subcutaneous anterior knee mass herniated from the infrapatellar fat pad (IPFP) through a focal defect of the patellar retinaculum (PR).

MATERIALS AND METHODS

This study included 94 patients (44 men; age range, 1-80 years; mean age, 52 years) with clinically palpable subcutaneous anterior knee masses who underwent MRI between January 2007 and July 2022. Two radiologists retrospectively reviewed MRI findings of subcutaneous masses associated with a focal PR defect (location and size of the defect and characteristics of the mass).

RESULTS

Among 94 patients, 15 (16%; 5 men; age range, 49-80 years; mean age, 67 years) had subcutaneous masses herniated from the IPFP through a focal PR defect. The defect was single (13/15, 87%) and more frequently observed in the lateral than in the medial (11/15, 73% vs. 4/15, 27%) PR. The defect occurred in the anterior segment (15/15, 100%) and was more frequently observed in the lower (10/15, 67%) than in the middle (5/15, 33%) and upper portions (0/15, 0%). The mean maximum length of the defect in axial and oblique planes was 14 mm and 25 mm, respectively. The defect-associated subcutaneous masses included lipomatous lesion (6/15, 40%), osteochondromatous lesion (5/16, 33%), and synovial fluid or ganglion cyst (4/15, 27%).

CONCLUSION

Subcutaneous anterior knee masses were associated with a focal PR defect in 16% cases. The location of a focal PR defect was characterized by the lateral, anterior, and lower segments.

Suprapatellar Fat Pad Impingement due to Vascular Lesion: A Case Report

CASE

We present a fifteen-year-old adolescent boy with anterior knee pain and a palpable tender swelling in the suprapatellar region with painful terminal extension. Imaging was suggestive of a vascular lesion in the suprapatellar fat pad. He underwent arthroscopic debridement and postoperatively regained his terminal extension.

CONCLUSION

Suprapatellar fat pad impingement can rarely be due to vascular lesions or lipomatous tumors affecting the suprapatellar fat pad. If conservative treatment is unsuccessful, surgery can provide good pain relief. The tissue excised should always be sent for histopathological examination.

Location, Clinical Presentation, Diagnostic Algorithm and Open vs. Arthroscopic Surgery of Knee Synovial Haemangioma: A Report of Four Cases and a Literature Review

Objective: The aim was to report 4 patients with intra-articular knee synovial haemangioma (KSH) and to perform a systematic review to describe the patient characteristics, patterns of tumor location, clinical presentation, usefulness of imaging examinations, pros and cons of arthroscopic vs. open resection, and follow-up in the literature.

Design: From 1996 to 2016, four patients with KSH were retrospectively reviewed. A literature search was conducted in PubMed from 2000/01 to 2020/06 using the search terms “synovial haemangioma” and “knee.” Fifty full-text articles that included a total of 92 patients were included for further discussion.

Results: Four adults (20–40 years) were diagnosed with KSH. Three lesions located in the suprapatellar pouch, two eroding the patella and one the supratrochlear bone, and one in the posterior compartment. Persistent anterior knee pain was the main complain. MRI revealed a benign tumor mass in all cases except one. Open excisional biopsy and regional synovectomy were performed in three patients, and by arthroscopy of the posterior compartment in the fourth. Histological type was arteriovenous in three cases and capillary in one. A pain-free knee without recurrence was achieve in all cases except one, which was successfully reoperated. Average follow-up time was 3.5 years. A literature review showed that KSH appears most frequently in children and teenagers (64.6%) and does not differ by gender. The suprapatellar and patella-femoral joint compartment was the most frequent location (47.9%). The bony tissue of the knee was rarely affected (13.5%). Pain, swelling and haemarthrosis were frequently reported (88.2, 66.7, and 47.1%). MRI was the most commonly used imaging test (98%). Treatment consisted of regional synovectomy by open surgery or arthroscopy in 66.7 and 15.6% of cases, respectively.

Conclusions: KSH should be considered in the differential diagnosis of adult patients with chronic low-intensity knee pain. MRI is the most useful exam because it establishes the location, extent and benign characteristics of the tumor. Definitive diagnosis requires histological examination. We believe excisional biopsy and regional synovectomy by arthroscopy should be the treatments of choice for intra-articular tumors, but we recommend open surgery when the lesion extends to the tendons, muscle or bone.

Intra-articular Synovial Hemangioma: A Rare Cause of Knee Pain and Swelling

Synovial hemangioma is a rare intra articular lesion and it has several more common differentials. Therefore, our main objective is to consider the possibility of hemangioma in any intra-articular mass to prevent diagnostic delay of unnoticed or untreated hemangioma occurring within the knee joint. Ultrasound can be useful method in assessing the lesions. Surgical excision is the definitive treatment for such lesions.

Synovial Hemangioma of the Wrist With Cystic Invasion of Trapezoid and Capitate Bones

Synovial hemangiomas (SHs) are rare lesions of the joints or tendon sheaths that are difficult to diagnose. We present the case of an 18-year-old man with an SH in the wrist joint. Physical examination revealed a slightly tender, ill-defined, nonpulsatile soft mass, 3 cm × 3 cm in size on the dorsal aspect of the left wrist. Computed tomography showed an irregular, ill-defined, soft tissue mass in the expanded joint space, which was formed by the scaphoid, trapezoid, and capitate bones. Magnetic resonance imaging showed the typical features of SH and also revealed cavitary erosion of the scaphoid, trapezoid, and capitate bones. An open arthrotomy was performed via a dorsal approach, and the mass was excised. The histological examination findings were consistent with the diagnosis of SH.

Synovial hemangioma of the knee joint in pediatrics: our case series and review of literature

BACKGROUND

Synovial hemangioma is a benign intra-articular tumor. This condition is rare and unfamiliar soft tissue tumor to most orthopedic surgeons. Delayed diagnosis causes osteoarthritic damage and the destruction of joint structures due to infiltrating tumor growth. We discuss the patterns of tumor location and the appropriate surgical procedure for this condition.

METHODS

Ten patients were treated surgically in our department. These comprised five males and five females ranging in age from 0 to 17 years (average age 12.4 years). Preoperative diagnosis was made using clinical findings, plain radiographs and magnetic resonance imaging. The follow-up time after surgery was at least 3 years.

RESULTS

The main symptom was pain. Three cases revealed hemarthrosis. The range of motion of the affected knee joint was limited in five cases. The average time between onset of pain and diagnosis was 3 years. Tumor location was classified into three patterns: (1) anterior patellofemoral joint type in five, (2) posterior popliteal type in two and (3) diffuse proliferation type in two. Open arthrotomy with synovectomy was performed in all cases. No tumor recurrences were experienced after a minimum follow-up of 3 years.

CONCLUSION

Clinical symptom and magnetic resonance imaging are helpful to obtain the diagnosis and determine the extent of the lesion. Depending on the tumor location, synovial hemangioma in the knee joint can be classified into patellofemoral, popliteal and diffuse types. Open arthrotomy with sufficient tumor and synovectomy is important to prevent tumor recurrence.

Synovial Haemangioma of the Elbow: A rare paediatric case and imaging dilemma

Synovial haemangiomas are rare benign vascular proliferations arising in synovium-lined surfaces. While the knee is by far the joint most commonly involved, this condition can also occur in the elbow. We report an eight-year-old boy who presented to the National University of Malaysia Medical Centre, Kuala Lumpur, Malaysia, in 2016 with a left elbow swelling of one year's duration. Magnetic resonance imaging showed a lobulated intra-articular mass with intermediate signal intensity on T1-weighted imaging and low signal punctate and linear structures within the hyperintense mass on T2-weighted imaging. In addition, there was heterogeneous yet avid contrast enhancement on post-gadolinium contrast images. The mass had juxta-articular extension and bony erosion to the coronoid process and the head of the radius. Synovial haemangiomas present a diagnostic dilemma. This report highlights certain imaging characteristics to distinguish this entity from other differential diagnoses.

A Focal Defect at the Lateral Patellar Retinaculum on Clinical Knee MRI and Cadaveric Study: A Normal Variant or Pathologic Lesion?

OBJECTIVE

The purpose of this study is to retrospectively investigate the frequency of a focal defect at the lateral patellar retinaculum on knee MRI and to determine the variables that are significantly associated with the defect.

MATERIALS AND METHODS

Two radiologists independently reviewed 99 knee MR images for the presence of a focal defect at the lateral patellar retinaculum and categorized patients with concordant results into two groups: a group with the defect (≥ 3 mm; group 1) and a group without the defect (< 3 mm; group 2). Clinical and radiologic variables, including the Kellgren-Lawrence radiographic grade, subcutaneous fat thickness, infrapatellar fat pad area, and the amount of joint effusion, were evaluated. The size and location of the defect were measured in group 1. To correlate MRI and histologic findings, MRI was performed for 11 cadavers, and three histologic specimens were obtained.

RESULTS

Of the 99 knee MR images, concordant results between two reviewers were obtained for a total of 96 knees (97%): 25 knees (26%) in group 1 and 71 knees (74%) in group 2. A statistically significant difference between groups (p = 0.033) was noted for the infrapatellar fat pad area only. In all three cadaveric specimens, the lateral patellar retinaculum was more loose and sparse than the medial patellar retinaculum, and this site corresponded to the location of the defect on MRI.

CONCLUSION

A focal defect of the lateral patellar retinaculum was not found to be a rare finding on knee MRI (frequency, 26%), and it may be a normal variant rather than a pathologic change. In addition, we suspect that a focal defect can be a route of infrapatellar fat herniation and a route of superficial extension of the infrapatellar fat pad lesion without a lateral patellar retinaculum tear or invasion.