Characteristic imaging findings of tendinosis of the direct head of rectus femoris and their interpretation

Endoscopic Resection for Iliopectineal Bursitis Associated With Developmental Dysplasia of the Hip

Iliopectineal bursitis usually develops subsequent to other hip pathologies and can often be treated conservatively. However, when conservative treatment fails or the enlarged bursa causes pain or compression of the surrounding neurovascular structures, surgery may be required. Most previous studies have described open surgeries, and reports on endoscopy are very limited. We present a case of iliopectineal bursitis associated with developmental dysplasia of the hip (DDH) that was successfully treated endoscopically. A 16-year-old female with a one-year history of right inguinal pain was referred to our department. She was diagnosed with a hip ganglion and treated with needle aspiration nine times by her previous doctor. Radiographs revealed bilateral DDH without narrowing of the joint space. Magnetic resonance imaging revealed a distinct mass in the deep layer of the iliopsoas muscle, and communication between the mass and the hip joint was observed on ultrasonography. Endoscopic debridement and resection were performed based on the diagnosis of iliopectineal bursitis. We partially debrided the medial side of the rectus femoris muscle toward the deep layer and resected the bursa. We observed a burst of concentrated content from the bursa and confirmed the disappearance of the mass by intraoperative ultrasonography. The postoperative course was good, and there were no functional restrictions or symptom recurrence at two-year postoperatively. Endoscopic resection for repetitive iliopectineal bursitis without an intraarticular procedure does not induce hip instability in patients with DDH and is a minimally invasive cosmetic procedure, and superior to open surgery, especially in young women.

Spatial distribution of loose connective tissues on the anterior hip joint capsule: a combination of cadaveric and in-vivo study

Recently, pathological changes in the fat pad on the anterior inferior iliac spine (AIIS), between the proximal rectus femoris and joint capsule, have been highlighted as a cause of anterior hip pain. However, precise fat pad features, such as the spatial distribution distal to the AIIS, histological features, and in vivo tissue elasticity, remain unclear. This study aimed to investigate the morphological characteristics of the fat pad on the AIIS. Four hips from four cadaveric donors were both macroscopically and histologically investigated, and eight hips from four volunteers were assessed using ultrasonography. The fat pad on the AIIS was also surrounded by the iliopsoas and gluteus minimus, extending distally to the superficial portion of the vastus lateralis, and the anterior portion of the gluteus maximus tendon. Histological analysis revealed that the fat pad was composed of loose connective tissue. Based on the ultrasonography, the shear wave velocity in the fat pad was significantly lower than that in the joint capsule. Conclusively, the pathological adhesion between the joint capsule and pericapsular muscles, if caused by fat pad fibrosis, may occur following the abovementioned fat pad spatial distribution.

Increased external rotation of the osteoarthritic knee joint according to the genu varum deformity

PURPOSE

To evaluate the rotational profile of the lower extremity using computed tomography (CT) in accordance with the degree of varus deformity in medial condyle-affected knee joint osteoarthritis (OA).

METHODS

This retrospective study included 1036 patients (872 lower extremities) with end-stage knee OA. The coronal alignment of the lower extremity was measured using standing anteroposterior radiography. The CT parameters of femoral anteversion and tibial torsion were assessed in relation to the knee joint. The axes were the femoral neck axis; the distal femoral axis, which was composed of the anterior trochlear axis, the clinical transepicondylar axis, and the posterior condylar axis; the axis of the proximal tibial condyles; and the bimalleolar axis.

RESULTS

There was a tendency for increased external rotation of the knee joint parameters in relation to the hip and ankle joints as varus deformity of the lower extremity increased. The relative external rotational deformity of the knee joint in relation to the hip joint had a positive value with a good correlation. The relative external rotational deformity of the knee joint in relation to the ankle joint also demonstrated a positive value with a good correlation.

CONCLUSION

The distal femur and proximal tibia (knee joint) tended to rotate externally in relation to the hip and ankle joint, respectively, as the degree of varus deformity increased. This study identified the relationship between lower extremity varus deformity and rotational deformity of knee joints with OA.

LEVEL OF EVIDENCE

III.