Shinji Yoshioka

Subchondral cysts in dysplastic osteoarthritic hips communicate with the joint space: analysis using three-dimensional computed tomography

IntroductionBone cyst formation in hips increases as osteoarthritis worsens. Although bone cysts in hips have been described in many studies, their etiology remains unclear and under debate. The purpose of this study was to investigate the communication between a bone cyst and the joint space, as well as the relationship between the severity of osteoarthritis and the formation of subchondral bone cysts in dysplastic hips.MethodWe studied bone cysts from 150 dysplastic hips in 97 patients by computed tomography (CT) and plain radiography. We investigated the distribution of the bone cysts and the presence or absence of a communication path between the cysts and the joint space by three-dimensional (3D) CT.ResultOf the 150 hips, 94 acetabula and 55 femoral heads were found to contain cysts. Of the 94 hips containing acetabular cysts, 89 and 5 hips showed black lines and gray lines connecting the cyst and the joint space, respectively, on 3D-CT. The rate of cyst presentation in the hip increased as the joint space became narrower. The number of hips that possessed cysts in the anterior and/or middle portion was significantly higher than that in the posterior portions.ConclusionBone cysts in dysplastic osteoarthritic hips were found to communicate with the joint space in all cases. This suggests that the formation and enlargement of the cysts in dysplastic hips may be greatly influenced by the joint fluid. Cyst formation was initially observed in the anterior acetabulum, gradually progressing to involve the entire joint, including the posterior acetabulum and the femoral head, with worsening of the osteoarthritis.

Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report.

We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent in the region innervated by L5 and S1 nerve roots. Preoperative multidetector three-dimensional computed tomography (3D-CT) showed complete absence of the right S1 superior articular process. Magnetic resonance (MR) images showed lumbar disc herniation at right L5-S1 level that migrated cranially. Intraoperative findings revealed that the right L5 nerve root and S1 nerve root were conjoined, and the conjoined nerve root was compressed by L5-S1 disc herniation, which led to impairment of the conjoined nerve root by a single-level lumbar disc herniation. After removal of the disc herniation, his right leg pain immediately subsided, however muscle weakness and sensory disturbance persisted. Surgeons should be aware of this nerve root anomaly when examining a patient who shows an unusual clinical presentation and/or congenital osseous anomaly.

Intrapelvic Migration of the Lag Screw in Intramedullary Nailing

Internal fixation with intramedullary devices has gained popularity for the treatment of intertrochanteric femoral fractures, which are common injuries in the elderly. The most common complications are lag screw cut out from the femoral head and femoral fracture at the distal tip of the nail. We report here a rare complication of postoperative lag screw migration into the pelvis with no trauma. The patient was subsequently treated with lag screw removal and revision surgery with total hip arthroplasty. This case demonstrated that optimal fracture reduction and positioning of the lag screw are the most important surgical steps for decreasing the risk of medial migration of the lag screw. Furthermore, to prevent complications, careful attention should be paid to subsequent steps such as precise insertion of the set screw.

Open dislocation of the proximal interphalangeal joint of the little finger subsequent to chronic radial collateral ligament injury: a case report of primary ligament reconstruction with a half-slip of the flexor digitorum superficialis: Case Report

Open dislocation of the proximal interphalangeal (PIP) joint is relatively rare. We report a case of a 32-year-old man who had open dislocation of the PIP joint of the little finger while playing American football. He had a history of chronic radial collateral ligament injury. We reconstructed the radial collateral ligament with a half-slip of the flexor digitorum superficialis tendon.

Osseous erosion by herniated nucleus pulposus mimicking intraspinal tumor: a case report.

Erosion of spinal osseous structure, so-called scalloping, has been rarely reported associated with herniated nucleus pulposus (HNP). We report a rare case of HNP causing erosion of the spinal osseous structure (including lamina). The patient was an 81-year-old woman with 3-year history of low-back pain and left leg radiating pain. Muscle weakness of the left leg was also apparent. Computed tomography following myelography showed severe compression of the dural sac at the level of L3–L4; furthermore, erosion of the lamina, pedicle, and vertebral body was noted, indicating that the space-occupying mass was most probably a tumorous lesion. The mass also showed calcification inside. During the surgery, the mass was confirmed to be an HNP with calcification. Following resection, the pain disappeared. Surgeons should be aware of the possibility of scalloping of the vertebrae caused by HNP mimicking a tumorous lesion.

Failure rates of Asian-type anatomic medullary locking stemmed metal-on-metal total hip replacement: A cause for adverse tissue reactions to metal debris (ARMD)

BACKGROUND Adverse tissue reaction to metal debris (ARMD) as a secondary complication of Metal-on-metal total hip replacement (MoM THR) has been of concern. We have been performing cementless MoM THR using an Asian-type anatomic medullary locking (AML) stem. The purpose of this study is to examine the incident rate of ARMD, and the implant survival rate. METHODS The study included 187 patients (211 hip joints) who underwent MoM THR between February 2007 and November 2009 at our hospital and who were followed up for a minimum of 6 years. The cases included 174 female joints and 37 male joints. The average age at the time of surgery was 68.4 years. The average postoperative follow-up period was 87.5 months. RESULTS ARMD was observed in 23 joints postoperatively, and the incidence rate was 10.9%. Most of the instances occurred within the first 30 months postoperatively. Revision surgery was performed for 14 joints after conservative treatment failed, and we changed the bearing surface. During the intraoperative observation, black-colored deposition of metal debris on the head-neck junction was observed in 13 cases. Kaplan-Meier analysis using the replacement surgery as the end point showed that this implant has a survival rate of 93.8% 7 years after the primary surgery. CONCLUSIONS We conclude that the major cause of failure of Asian-type AML stemmed MoM THR is likely the breakage of the fixation between the taper neck and metal head at the head-neck junction.

Bilateral Atypical Femoral Fractures in a Patient with Multiple Myeloma Treated with Intravenous Bisphosphonate Therapy

Bisphosphonates are currently the standard approach to managing bone disease in multiple myeloma. Bisphosphonates have high bone affinity that inhibits osteoclastic activity and additionally reduces the growth factors released from malignant or osteoblastic cells, thereby impairing abnormal bone remodeling which leads to osteolysis. However, patients of multiple myeloma may be at a higher risk of atypical femoral fractures because the treatment for malignant myeloma requires notably higher cumulative doses of bisphosphonates. Here we present a patient with bilateral atypical femoral fractures and multiple myeloma treated with intravenous bisphosphonate therapy.

One-Stage Reconstruction for Re-rupture of Achilles Tendon with Soft Tissue Infection: Using an Anterolateral Thigh Flap Incorporating a Vascularized Muscle Flap and a Strip of Iliotibial Tract

Reconstruction is challenging in a patient with loss of a segment of Achilles tendon and infection in the overlying soft tissue. Here the authors describe one-stage tendon reconstruction, using an anterolateral thigh free flap incorporating a vascularized muscle flap and a strip of iliotibial tract in a patient with re-rupture of an Achilles tendon and soft tissue infection. Postoperative immobilization of the affected ankle using an external fixator enabled us to observe the flap directly and reduce pressure on the flap. The patient had a successful outcome, with no difficulty in walking, running, or climbing stairs and no limitation of range of motion at the ankle joint postoperatively. This is a promising technique for reconstruction of the Achilles tendon and treatment of infection as a one-step procedure.

Osteomyelitis Caused by Candida glabrata in the Distal Phalanx

Osteomyelitis caused by Candida glabrata is rare and its optimal treatment is unknown. Here we report a case of osteomyelitis caused by C. glabrata in the distal phalanx in a 54-year-old woman. Despite partial resection of the nail and administering a 1-month course of antibiotics for paronychia, the local swelling remained and an osteolytic lesion was found. C. glabrata osteomyelitis of the distal phalanx was later diagnosed after curettage. Thereafter, the patient was treated with antifungal agents for 3 months. The infection eventually resolved, and radiological healing of the osteolytic lesion was achieved. Antifungal susceptibility testing should be performed in the case of osteomyelitis caused by nonalbicans Candida species, due to their resistance to fluconazole.

MORPHOLOGICAL STUDY OF THE ENTRAPMENT POINT OF UPPER EXTREMITY

The morphological study of cubital tunnel, carpal tunnel and the ulnar (Guyon) canal of adult cadavers was done using stereoscopy after injection of the resin into the brachial artery. MRI (Magnetic Resonance Imaging) of the carpal tunnel was also performed for normal volunteers. In the area of sulcus nervi ulnaris at the elbow, the amount of fibrofatty tissue was extremely small in the nerve trunk, and the nerve was superficially located and found to run close to the hard bony tissue. At the distal margin of the bony sulcus of the ulnar nerve, the nerve ran on the base of hard collateral ligament, where it was covered with a hard ligamentous aponeurosis. The nutrient vessel to the epineurium of the nerve did not exist in the tunnel under the cover of aponeurosis and the nerve was fed by vessels at the entrance of the tunnel and by the recurrent vessels ascending from the musculature at the distal end of the tunnel. The thickness of the flexor retinaculum from the inlet to the midst of carpal tunnel increases and the thickness became maximum at the outlet. The images of MRI of the carpal tunnel were similar to the corresponding levels, and demonstrated the accuracy of imaging with the anatomical relationships. The ulnar canal itself had few bone elements, and there were neither tight connective tissue nor tendons on the palmar side except for the inlet portion.