212 • James C.C. Leisen, Howard Duncan, and J.M. Riddle 



allowed examination with the naked 

 eye or a dissecting microscope. 



We used the following terms to de- 

 fine specific anatomic sites: Articular 

 surface indicated the joint surface orig- 

 inally covered by articular cartilage. 

 The chondro-osseous junction defined 

 the discrete line of contact between ar- 

 ticular cartilage and bone at the joint 

 periphery. Para-articular bone referred 

 to epiphyseal bone anatomically lo- 

 cated within the joint capsule and adja- 

 cent to the chondro-osseous junction. 



Bony features described were the 

 following; Holes were defined as any 

 circumscribed break in the bony sur- 

 face which exposed the marrow space 

 or underlying trabecular bone (Duncan 

 et al. 1987:1212). The edges of the 

 holes were called sclerotic if they were 

 rounded and slightly raised and/or 

 thickened. An osteophyte was defined 

 as any bony proliferation on or around 

 the edge of the articular surface. 



Figure I . Hemisection of cadaver metacarpal head (left) and a rheumatoid metacar- 

 pal head (right) showing erosion of articular surface associated with the infiamma- 

 tory process; x 2. 



Results 



GROSS OBSERVATIONS AND 

 DISSECTING MICROSCOPE VIEWS 



The unmacerated cadaver and amputee 

 specimens (metacarpal heads and tibial 

 plateaus) showed no pannus formation 

 and only minimal articular cartilage 

 fibrillation by examination with the 

 naked eye. No radiographic chondro- 

 calcinosis was seen. 



The articular surface, chondro-os- 

 seous junction and para-articular struc- 

 tures on macerated control samples 

 were easily identified. Prominent fea- 

 tures of the control macerated metacar- 

 pal heads included: ( I ) condylar emi- 

 nences which were most pronounced 

 on the radial side, (2) a convoluted 

 chondro-osseous junction, and (3) deep 

 bony invaginations in the valleculac 

 just posterior to the condylar emi- 

 nences. These valleculae contained at 

 least one dominant hole which was the 

 site of entry of blood vessels originally 

 supplying the bony epiphysis (Figure I , 

 left). 



The medial and lateral plateaus of 

 tibial tables removed from the cadavers 

 and above-the-knee amputees were dis- 

 tinct and separated by a central, ele- 

 vated prominence (Figure 2). The artic- 

 ular surfaces of the plateaus appeared 

 smooth when viewed with the naked 

 eye or the dissecting microscope. 



Gross examination of the rheumatoid 

 specimens by contrast showed varying 

 degrees of architectural destruction and 

 variable amounts of pannus. Partial to 

 complete resorption of the articular sur- 

 face was seen in the macerated speci- 

 mens. Loss of the articular surface on 

 the rheumatoid metacarpal heads was 

 most noticeable on the condylar emi- 

 nences where seven of ten specimens 

 showed complete resorption and three 

 samples showed partial destruction 

 (Figure I , right). In three specimens, 

 the articular surface over the condyles 

 was also perforated by many large 

 holes. A small cap of residual surface 



remained intact on the radioulnar as- 

 pect of five metacarpal heads. In ail 

 specimens, there was circumferential 

 loss of the chondro-osseous junction, 

 and the para-articular bone was 

 grooved as well as excavated. Many 

 holes showed no evidence of sclerosis 

 around their edges. Ebumation was 

 seen on the articular surface in two of 

 the rheumatoid specimens (Table 1). 

 The rheumatoid tibial plateaus often 

 showed that the articular surfaces were 

 ebumated toward the intercondylar 

 areas. Both the submeniscal and central 

 surfaces of the plateaus contained many 

 holes without sclerotic rims through 

 which the marrow space and/or tra- 

 becule were visible. In some areas the 

 chondro-osseous junctions were oblit- 

 erated. Para-articular bone contained 

 low ridges of small bony osteophytes 

 (Table 2). The intercondylar area in all 

 specimens had many holes with little 

 surrounding sclerosis (Figure 3). 



Ziifireh Pulftipatluil(t}>y Symp. 1988 



