A novel exogenous concentration-gradient collagen scaffold augments full-thickness articular cartilage repair

OBJECTIVES

A collagen scaffold has been long used in order to enhance the regeneration of articular cartilage. In the present study, we investigate the effectiveness of a concentration-gradient (CG) collagen that is designed to recruit efficiently the mesenchymal stem cells (MSCs) to the central region of the full-thickness cartilage defects via haptotaxis.

METHODS

The present study used Cellmatrix (0.3% type I collagen; Nitta gelatin, Osaka, Japan) as the collagen material. We prepared 33%CG collagen gel and 50%CG collagen gel. No gradient collagen gel served as negative control. Full-thickness cartilage defects were created at the patella groove of the rabbit knee, to which the three different collagen gels were transplanted. Bromodeoxyuridine (BrdU) positive, proliferating cells were enumerated and localized, whereas the histological grading score for cartilage regeneration was counted. The expression of type I and type II collagens was evaluated by immunohistochemistry. We also confirmed that the MSCs migrate toward the collagen substrate of higher concentration in a stringently in vitro haptotactic manner.

RESULTS

Enumeration of the BrdU-positive cells demonstrated that 33%CG collagen gel recruited a significantly larger number of proliferating cells to the central region of the cartilage defect. The histological grading score for the regenerated cartilage treated with 33%CG collagen gel was superior to the other groups.

CONCLUSIONS

CG collagen scaffold recruits effectively the MSCs to the center of full-thickness cartilage defect and enhances regeneration of the full-thickness cartilage defect.

Congenital unilateral upper limb muscular hypertrophy associated with contracture of an extrinsic extensor tendon

We report a case of congenital unilateral upper limb muscular hypertrophy which presented with loss of extensor tendon excursion of a single digit in late adolescence. The reason for the problem arising is not clear and is not clearly explained by the underlying congenital pathology.

Intramedullary spinal cord metastasis of ovarian tumor

STUDY DESIGN

Case report.

OBJECTIVES

To report a case of a thoracic intramedullary spinal cord metastasis of ovarian tumor in a 59-year-old woman.

SETTING

Shiga, Japan.

CASE REPORT

A case of a thoracic intramedullary spinal cord metastasis of ovarian tumor in a 59-year-old woman is reported. She received abdominal ovariectomy for the ovarian adenocarcinoma 4 years before she suffered from back pain and showed neurological symptoms. The thoracic intramedullary lesion was confirmed by preoperative magnetic resonance imaging. She showed complete paralysis before operation. The excision of the tumor was achieved through the posterior approach. Histologically, the diagnosis of metastasis of adenocarcinoma was made.

CONCLUSION

Although she did not show any postoperative neurologic recovery, her general condition was good and there was no evidence of recurrence 24 months after surgery.

Locking of metacarpophalangeal joints in a patient with acromegaly

A 39-year-old man with acromegaly exhibited locking of metacarpophalangeal (MCP) joints of both index fingers. Large osteophytes were found at the metacarpal heads by radiography and computerized tomography (CT). Magnetic resonance (MR) images revealed hypertrophy of volar plates. We suggest that these characteristic acromegalic features caused locking of MCP joints. Surgery was required on one of the joints to release the locking.