17-t 
071 the Sesamoids of the Knee- Joint 
n = M. popUteus biceps (Fig. 9), o = internal supracondylar tubercle, p=processus tuberositatis of the 
internal condyle for the insertion of the tendon of the adductor muscle, 7 = superficial and 5 (engraved 5 
in Figs. 9 and 10) = deeper layers of the under " strangformig " portion of the tendon of origin of 
M. gastrocnemius externus. 
Fig. 8 shows the only mesial fabclla, 5, observed by Gruber; it was a pathological ossification, 
a being the upper vertical, and /3 the transversal limb of this pseudosesamoid ; it appears to be associated 
with a somewhat emphasised tuberosity of the internal condyle, p. 
Fig. 9. A most interesting illustration of the anomaly of M. popliteus biceps, n, of the two branches 
n" is the outer deeper head and n' the supernumerary inner and superficial head attached to the 
external /afcf/Za. Tlhia fabella (4) appears as a " Knotenpunkt " of tendon of M. gastrocnemius k{5 = S) 
of the short external lateral ligament (d), and its posterior face is shown by the removal of M. gastro- 
cnemius (k) and 31. plantaris (1). 
Plate V, Fig. 10. Left knee-joint seen in posterior aspect. We see the ossicle exposed with its upper 
inner and outer surfaces, the head of origin of M. gastrocnemius being cut through and drawn back over 
the ossicle (4). We see the ossicle attached to the ligamentum popliteum (6) and the short external 
lateral ligament {d). The position of the sesamoid and its shape are unusual for & fabella. It appears to 
be low down on the external face of the latei-al condyle, and approaching the popliteal sulcus. Its position 
seems at least transitional from that of fabella to that of cyamella. 
Fig. 11. Eight knee-joint in posterior aspect. The fabella lateralis (4) is seen wedged in so to speak 
between gastrocnemius [k) &nd plantaris {I). This is the position given for it by Cheselden in 1733, and 
more fully recognised by Sommering in 1841 : see our pp. 150 and 151. 
Fig. 12. Left knee-joint in posterior aspect. The fabella lateralis (4) has been freed from gastro- 
cnemius {k) and seen in relation to the ligamentum popliteum (b), the short external lateral ligament (d), 
and by the opened knee-capsule {a) in relation to its position on the external condylar surface. 
It will be seen how great an advance Gruber made in our knowledge of the muscular and ligamental 
attachments of the fabellae. 
Fig. 13. Sesamoid of the external condyle in the case of the Wombat (after Pfitzner). This sesamoid 
rests on the head of the fibula, and appears to be directly associated with the para fibula of other Australian 
types, and again the direct articulation of fibula with the external condyle in other species. These points 
are discussed in Part II of the present memoir. 
Plate VI. Drawings of an actual case of the fabella lateralis in man from a cadaver in the 
Dissecting-Eoom at University College. 
Fig. 14 is a sagittal section of the left femur showing the position of the fabella before M. gastro- 
cnemius was turned back. Fig. 15 shows the fabella in the tendon of the muscle after it has been turned 
back and the facette on the articular surface of the condyle in which it rested. The closeness of contact 
differs considerably from the usual position as indicated in the skiagrams: see Plates VII — IX. 
Plate VII, Fig. 16 and Fig. 17. Lateral fabellae. 
Plate VIII, Fig. 18 and Fig. 19. Lateral fabellae. 
Plate IX, Fig. 20. Small lateral /aieiia. Fig. 21, Large lateral /aftcWa, probably differing from the 
previous illustrations in resting in a facette on the articular surface of condyle. Cf. Plate VII. 
Plate X. Most probably a lateral cyamella in the neighbourhood of the popliteal sulcus in posterior 
(Fig. 22) and anterior (Fig. 23) aspects. Is there evidence of a mesial cyamella! 
Plate XI. There is some evidence in favour of a mesial cyamella placed in the groove on the internal 
epicondyle in Fig. 24. Fig. 25 gives a fair example of a lateral cyamella in the popliteal sulcus. 
Plate XII, Fig. 26. There is a small bone in the semi-lunar, which may be a posterior lateral lunula. 
Fig. 27 gives more definite evidence of an anterior lateral lunula. Both of these lunulae are fairly 
smoothly shaped and do not resemble pathological ossifications : at the same time the damaged 
condition of lateral condyle in Fig. 26 prevents any stress being laid on the former case. In Fig. 27 
there appears to be a well shaped sesamoid at the head of the fibula in close proximity to the lunula. 
Plate XIII, Fig. 28. This must be taken in conjunction with Plate XIV, Fig. 30. In both dases we 
have an ossification of the tendon of the quadriceps extensor muscle. In both cases it may be considered 
as pathological, but at the same time its general resemblance to the double or "tandem " patella, which 
