Does the meniscus exist in the elbow joint in children?

A Comprehensive Review of Radiohumeral Synovial Plicae for a Correct Clinical Interpretation in Intractable Lateral Epicondylitis

PURPOSE OF REVIEW

Radiohumeral synovial plicae (RHSP) have been studied by different authors in different ways; in spite of this, the evidence is poor and the results are controversial and inconclusive even when it comes to referring to this elbow structure. The aim of this article is to review the embryologic development, anatomy and histology, pathophysiologic features, clinical manifestations, physical examination, imaging findings, and treatment of radiohumeral synovial plicae, for their correct clinical interpretation in patients with intractable lateral epicondylitis.

RECENT FINDINGS

Radiohumeral synovial plicae syndrome (RHSPS) can cause intractable lateral epicondylitis and can be easily confused with other clinical conditions affecting the elbow. Many clinicians are not familiar with radiohumeral synovial plica syndrome since there are not many studies about it and previous reports do not seem to reach a consensus. Although its role in elbow injuries and epicondylitis is accepted and its surgical treatment is effective, there is no clear consensus about clinically relevant aspects. RHSP are remnants of normal embryo development of the articular synovial membrane with different anatomical locations, size and shape. Traumatism or overuse can turn RHSP into symptomatic structures at any age and can be compressed between the radial and humeral heads during movement. This compression can cause pain and other symptoms such as snapping, catching, mobility restriction, pitching, clicking, locking, blockage, popping and swelling. Radiohumeral synovial plica syndrome (RHSPS) may be an isolated condition or it can be associated with other elbow abnormalities. The findings on physical examination and imaging diagnosis are multiple and variable. Nowadays, RHSPS are quite unknown and previous reports do not seem to agree, leading to misdiagnoses as epicondylitis and making this structure the main cause of some cases of "intractable lateral epicondylitis". The outcomes of surgical treatments are quite promising although more, higher quality research is needed. Taking this into account, this review is meant to be a starting point for new anatomical and clinical studies.

Prominent synovial plicae in radiocapitellar joints as a potential cause of lateral elbow pain: clinico-radiologic correlation

BACKGROUND

Thickened synovial plicae in the radiocapitellar joint have been reported as a cause of lateral elbow pain. However, few reports regarding diagnosis based on detailed physical examination and magnetic resonance imaging (MRI) findings are available. The aims of this study were to characterize the clinical manifestations of this syndrome and to investigate the clinical outcomes of arthroscopic surgery.

METHODS

We analyzed 20 patients who received a diagnosis of plica syndrome and underwent arthroscopic débridement between 2006 and 2011. The diagnosis was based on physical examination and MRI findings. Elbow symptoms were assessed using a visual analog scale for pain; the Mayo Elbow Performance Index; and the Disabilities of the Arm, Shoulder and Hand score at a minimum of 2 years after surgery. The thickness of plicae on MRI was compared with the normal data in the literature.

RESULTS

Plicae were located on the anterior side in 1 patient, on the posterior side in 15, and on both sides in 4. Radiocapitellar joint tenderness and pain with terminal extension were observed in 65% of patients. MRI showed enlarged plicae consistent with intraoperative findings. The mean plica thickness on MRI was 3.7 ± 1.0 mm, which was significantly thicker than the normal value. The mean lengths (mediolateral length, 9.4 ± 1.6 mm; anteroposterior length, 8.2 ± 1.7 mm) were also greater than the normal values. The visual analog scale score for pain decreased from 6.3 to 1.0 after surgery. The Mayo Elbow Performance Index and Disabilities of the Arm, Shoulder and Hand scores improved from 66 to 89 and from 26 to 14, respectively.

CONCLUSIONS

Specific findings of the physical examination and MRI provide clues for the diagnosis of plica syndrome. Painful symptoms were successfully relieved after arthroscopic débridement.

An approach to comparative anatomy of the acetabulum from amphibians to primates

The objective of this study was to investigate the anatomy, both macroscopic and microscopic, of the soft tissue internal structures of the hip joint in animal species and in three human hips (an adult and two fetuses). We dissected the hip joints of 16 species and compared the anatomical features of the soft tissue from the respective acetabula. In addition, a histological study was made of the specimens studied. In amphibians, we found a meniscus in the acetabulum, which was not observed in any of the other species studied. The isolated round ligament is observed from birds onwards. In the group of mammals analysed, including the human specimens, we found a meniscoid structure in the acetabular hip joint. Furthermore, we found that the meniscoid structure forms an anatomo-functional unit with the round ligament and the transverse ligament of the coxofemoral joint. These discoveries suggest the participation of the soft tissue anatomy in adaptative changes of species.

Lateral sided snapping elbow caused by a meniscus: two case reports and literature review

Lateral sided snapping elbow is an unusual condition, and it is apt to be misdiagnosed as lateral epicondylitis. The causes of lateral sided snapping elbow have been attributed to intraarticular loose bodies, instability, synovial plicae and torn annular ligament. We report our experiences for treating lateral sided snapping elbow caused by a meniscus in the radio-humeral joint. In the present cases, the cause of snapping was detected using double contrast arthrogram under fluoroscopic control, and histology revealed that it was a meniscus. Complete removal of the meniscus allowed immediate relief of the symptom, and there was no recurrence in both cases.

Intra-articular inclusions of the elbow joint complex

An abundant clinical literature implicates intra-articular inclusions in various pathological conditions of the elbow, but the anatomical literature offers piecemeal descriptions of these structures. The aim of this study was to determine the prevalence, disposition, and gross morphology of intra-articular inclusions of the entire elbow joint complex. Twenty-eight elbow joints from 17 adult embalmed cadavera were studied by macrodissection. Three types of inclusions were identified. Fat pads and fibroadipose meniscoids were found in all joints while capsular rims occurred in 50% of radiohumeral and humeroulnar joints. Fat pads were located opposite the olecranon, coronoid, and radial fossae. Fibroadipose meniscoids were found in the nonarticular waists of the trochlear notch and protruded into the posterolateral aspect of the radiohumeral joint. Fibroadipose meniscoids and fat pads are characteristic structures of the elbow joint complex. Fat pads appear to act as deformable space fillers, while the radio-humeral fibroadipose meniscoid appears to protect articular cartilage exposed during normal movement. Arguments are raised whether these structures may act as the nidus for arthrofibrosis and that the radiohumeral meniscoid may be involved in lateral epicondylalgia.

The posterolateral plica: a cause of refractory lateral elbow pain

Lateral epicondylitis is one of the most common upper extremity pain syndromes. We report the results of patients in whom conservative treatment was unsuccessful and who were finally treated arthroscopically for symptomatic plicae. Ten patients (mean age, 40 years [range, 18-60 years]) who were misdiagnosed as having lateral epicondylitis were included in this study. Examination revealed the site of maximal tenderness to be posterior to the lateral epicondyle and centered at the posterior radiocapitellar joint. Preoperatively, all patients received conservative treatment (physical therapy or corticosteroid injections [or both]). The mean follow-up was 25 months (range, 6-68 months). The mean score on the Disabilities of the Arm, Shoulder and Hand questionnaire was 9 (range, 0-37). Preoperatively, 7 patients had full elbow range of motion; however, in 3 patients, there was a loss of extension at the elbow ranging from 7 degrees to 20 degrees preoperatively. The range of elbow motion was full in all patients postoperatively. No patient demonstrated posterolateral pain after the operation. Synovial plicae of the elbow may be the cause of lateral elbow pain in patients with vague clinical symptoms. Arthroscopic management may provide a successful treatment option for such patients.

A meniscus causing painful snapping of the elbow joint: MR imaging with arthroscopic and histologic correlation

Snapping of the elbow joint can cause pain. We report a case of painful snapping elbow produced by an interposed meniscus in the radiohumeral joint in a 20-year-old man. The MR arthrogram demonstrated a meniscus-like tissue interposed between the radial head and humeral capitellum. The MR-arthrographic findings were well correlated with surgical findings. The location and appearance of the meniscus-like tissue was similar to that of meniscus in the knee joint. Histologic findings of the excised meniscus-like tissue showed a typical presentation of fibrocartilage. A meniscus may exist in the elbow joint and can be a rare cause of painful snapping elbow. MR arthrography is helpful for identifying the snapping tissue in the elbow joint.