Discoid Medial Meniscus: 2 Case Reports / 대한정형외과학회잡지

The vast majority of discoid menisci are lateral. A medial discoid meniscus is very rare. A 33-year-old and a 15-year-old male patient were diagnosed as having a complete medial discoid meniscus by means of magnetic resonance imaging and arthroscopic procedures. The first patient had a peripheral tear along with cystic degeneration, and the second had a horizontal tear. One was treated successfully by an arthroscopic partial meniscectomy with a peripheral repair, and the other by an arthroscopic partial meniscectomy. We report two cases of medial discoid meniscus with a brief review of literature.

Use of Structureal Allograft in Revision Total Knee Arthroplasty

PURPOSE: To analyze the clinical and radiological results after revision total knee arthroplasty(TKA) using structural allograft for severe bone defect, MATERIALS AND METHODS: Between l992 and 1997, we used structural allograft for revision TKA in 20 knees of 18 patients with severe bone defect, The average age at surgery was of 61.6 years. The follow-up period averaged 43 months(range, 1 3-80 months). All patients had severe bone defect of the femur and/or tibia. Ten distal femur and thirteen proximal tibia required allografting. Fresh frozen femoral heads were used in all patients. We used posterior stabilized stemmed PFC knee component in all cases except one case with constrained condylar type. Patients were evaluated with physical examination, radiographs and the Hospital for Special Surgery knee rating scale. RESULTS: Average range of motion before surgery was 87degrees and after surgery 107degrees. Average knee score was 65 before and 90.4 after surgery. Preoperative alignment averaged 1.8degrees valgus, ranging from 17degrees varus to 13degrees valgus, and postoperative alignment averaged 7,2 degrees velgus, ranging from 3degrees valgus to 10 val-gus, All patient improved pain and stability. Postoperatively average HSS score improved from 65(rang- ing from 46 to 92) to 90.4(ranging from 75 to 100). All of the allografts united with host bone. There was no radiolucent line, lysis, fracture and infection. CONCLUSION: Structural allograft can be a satisfactory method of managing large bone defects in the failed total knee arthroplasty.

Immunohistochemical Staining for Type II Collagen in Regenerated Cartilage after Microfracture Surgery / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to identify nature of regenerated articular cartilage after microfracture surgery. MATERIALS AND METHODS: From Oct. 1997 to Nov. 1998, 40 knees were treated for osteoarthritis by arthroscopic microfracture technique. In the 18 knees, during the second arthroscopic procedure, biopsy specimens extending to the subchondral bone were taken and immunohistochemical staining was done to identify type of collagen. One patient was man and 17 patients were women. Average age of the patients were 58 years (range, 40-75 years). RESULTS: Type II collagen in articular cartilage appeared to be brown color with this staining. Degree of staining were +3 in 4 knees(22%), +2 in 2 knees(11%), +1 in 7 knees(39%) and trace in 5 knees(28%). CONCLUSION: Microfracture surgery restores the function of the joint by forming predominantly hyaline-like cartilage containing type II collagen. As analyzing amounts of type II collagen with an immunohistochemical staining in regenerated cartilage, we can presume the prognosis of regenerated cartilage tissue after microfracture surgery.

Chondrolipoma of the Knee: A Case Report

Chondrolipoma is a benign tumor composed of mature adipose tissue and mature chondrocytes, and very rarely found. The patient, a 36-year-old woman, presented with a firm, walnut sized, mild tender mass at her left knee. There had been dull pain after long walking. There were no limitation of motion in physical examination. On plane lateral radiograph, radioopaque calcific densities were seen in elliptical soft tissue shadow below inferior pole of the patella. Magnetic resonance image demonstrated well defined mass of mixed signal intensity consistent with fat tissue and cartilaginous tissue. Gross specimen showed that the tumor appeared to be a round, encapsulated and firm nodule with milky whitish yellow cut surface. Microscopically the tumor consisted of nodular cartilage and mature fat tissue. The cartilage cells did not show mitotic figure and were often arranged in small clusters. But there were no cytologic features of malignancy. Thus the authors diagnosed this tumor as chondrolipoma, and report it with the literature review.