The Results of Spinous Process-splitting Laminoplasty Using Heterograft Spinous Process Spacer / 대한정형외과학회잡지

PURPOSE: To assess the effectiveness and safety of heterograft spacer (Lubboc) as a substitute for autograft in cervical laminoplasty. MATERIALS AND METHODS: 21 patients with cervical myelopathy were treated by spinous process splitting laminoplasty using heterograft intraspinous spacers. The clinical and the radiographic evaluations were checked pre- and postoperatively. RESULTS: The average JOA score was increased from 8.7 preoperatively to 12.9 at the final follow-up with a average recovery rate of 60.6%. Preoperative spinal canal diameter, 14.7 +/- 1.4 mm were improved to 20.1 +/- 1.8 mm postoperatively and canal to body ratio, 0.75 +/- 0.10 to 1.02 +/- 0.11 in average. The intraspinous spacer, heterograft demonstrated fragmentation and partial resorption mainly at the level of C3, 4, 5 from postoperative 2 months, but showed no clinical deterioration in spite of radiographic changes of heterograft. CONCLUSION: We think that heterograft spacer is one of the safe and effective substitutes for autograft in maintaining the improved postoperative radiographic indeces.

A Prospective Randomized Study of Arthroscopic and Microscopic Discectomy in Protruded Lumbar Disc Herniation / 대한정형외과학회잡지

PURPOSE: To obtain reliable clinical data arthroscopic discectomy, the authors compared the treatment results of the arthroscopic discectomy (AS) with microscopic discectomy (MS) only in the protruded type of lumbar disc herniations. MATERIAL AND METHODS: Each arthroscopic and microscopic discectomy groups consisted of 39 patients who were operated between May 1993 and October 1997. Minimum follow-up period was 12 months. Method of operation was selected at random and was performed under local infiltration anesthesia in all cases. Clinical and radiological results were evaluated by same protocol before and at one, three, six and 12 months after operation. The herniations of the AS group affected L4-5 in 35 patients and L5-S1 in 4 patients, and of MS group affected L4-5 in 31 patients and L5-S1 in 8 patients. Age, sex and level showed no statistical differences in both groups. RESULTS: Average admission periods were 2.8 days in AS and 4.8 days in MS group. The overall objective clinical result was satisfactory in 92% and 90% respectively. At L4-5 level, it was 97% and 87%, while 50% and 100% at L5-S1. In accordance with the direction of protrusion, midline type showed 100% and 83%, while posterolateral type showed 91% in both group respectively. Disc space height was changed in AS group from 12.2mm preoperatively to 11.2mm (8.3%) postoperatively, and in MS group, from 12.4mm to 10.9mm (16.9%) (p<0.05) . CONCLUSION: From the clinical and radiological results, it was concluded that although overall objective and subjective clinical results were similarly satisfactory in both methods, the clinical result of AS was better in L4-5 level, while that of MS were much better in L5-S1. Radiologically, narrowing of disc space height after AS were significantly less than in MS. So, arthroscopic discectomy is more recommended in the protruded type of lumbar disc herniation at L4-5 level than microscopic discectomy.

Analysis of Wear Particle in Association with Aseptic Loosening in Cementless Total Knee Arthroplasty

INTRODUCTION: Although most stable total knee arthroplasties remain so for many years, recently asep-tic loosening of prosthesis due to osteolysis which are induced by polyethylene wear is one of important causes in TKA failure. The authours experienced two cases of TKA revision due to aseptic loosening, and analysed wear particles in association with aseptic loosening. MATERIALS AND METHODS: From Oct 1988 to July 1999, two cases among 400 TKA underwent revision TKA due to aseptic loosening. The periprosthetic interface membrane tissues were collected for analysis of wear particle. After enzymatic digestion, EDS and FT-IR employed for chemical and physical charac-teristics and SEM employed for size and morphology of particle. RESULTS: Radiolucent line were seen around tibial component and aseptic loosening were observed also. At revision operations, hypertrophy of synovium and interface membrane between prosthesis & host bone were confirmed. Pathology showed synovial hypertrophy and giant cell which impressed chronic inflammation due to foreign body. The isolated particles were mainly polyethylene debris. And the size of the particle was variable. Some were identified grossly, several mm, others were several micrometer. Also, submi-cron particles were seen. CONCLUSIONS: If aseptic loosening was developed in TKA, polyethylene wear particle should be consid-ered as a cause of loosening. The wear particles were variable in sized and more bigger than that in previ-ous reports of THA.