1. Knee joint pathology in Ein Qashish 3 (EQH-3) Neandertal
Ella Been1, Yoel Rak2, Lihi Levin2, Barash Alon3, Ravid Ekshtain4, Omry Barzilai5
1Department of Physical Therapy, Ono Academic College; 2Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University; 3Faculty of Medicine, Bar Ilan University, Safed; 4Institute of archaeology,
The Hebrew University of Jerusalem; 5Israel Antiquities Authority
Introduction
Table 1: The distal femur of EQH-3, H. sapiens and Neandertals
Measurement
EQH-3
Recent H. sapiens
Early H. sapiens
Neandertals 
Maximum condylar width (mediolateral) (mm)
73.9
76.2 ± 2.3 (male)
69.8 ± 2.1 (female)
88.6 ± 4.2 (male)
78.5 ± 3.0 (female)
81.6 ± 6.7
(Qafze - Skhul h.)
84.3 ± 8.0
Maximum lateral condyle width (mediolateral) (mm)
22.7
25.3 ± 2.6
lateral condyle length (anteroposterior) (mm)
62.5
63.7 ± 5.1
61.1 ± 3.3 (male)
55.4 ± 2.1 (female)
68.8 ± 5.9
(Skhul h.)
66.4 ± 6.4
(N=7)
Maximum medial condyle width (mediolateral) (mm)
31.0
26.7 ± 2.7
Medial condyle length (anteroposterior) (mm)
61.6
61.1 ± 3.4 (male)
55.9 ± 2.9 (female)
61.3 ± 7.2
63.3 ± 8.7
Epiphyseal breadth ratio
16.9
17.1 ± 1.3
17.1 ± 1.2
18.9 ± 1.4
Intercondylar fossa width (mm)
10.7
22 ± 1.8 (male)
18.7 ± 1.0 (female)
Intercondylar fossa depth (mm)
24.8
27.8 ± 1.6 (male)
23.7 ± 2.0 (female)
‘Ein Qashish is a late Mousterian open-air site from the southern Levant bearing evidence of three discrete human fossil remains. One of the fossils, EQH-3, consisted five lower limb bones of a young adult Neandertal male (Been et al. 2015) that is the subject of the current paper.
One of the ‘unusual’ features of this individual was the narrow distal articular surface (Figure 1), while Neandertals are usually characterized by large articular surfaces. This morphology is part of some anatomical peculiarities found in the left distal femur and proximal tibia of EQH-3: a very narrow inter condylar notch, small lateral articular facet of the distal femur, and prominent tibial intercondylar eminence between the two tibial plateaus.
We assume that the nature of this special morphology could be a result of four possibilities:
This morphology is related to interbreeding between Neanderthals and H. sapiens.
This is a pleisiomorphic character, which can be found in the femur or tibia of other hominins.
It is the result of taphonomy.
The combination of these morphologies represent knee pathology.
The combination of the narrow intercondylar notch and the narrow lateral femoral condyle together with the high intercondylar eminence is often seen in the knee joint of children that experienced an avulsion fracture of the ACL (Perugia et al, 2009; Anderson and Anderson, 2015). Therefor the forth hypothesis is the most parsimonious explanation for the unique morphology of EQH-3 knee.
Method
In order to test which of the hypothesis is correct we compared the morphology of the distal femur and proximal tibia of EQH-3
with that of H. sapiens (modern and early), H. neanderthalensis, and H. erectus specimens.
Discussion
ACL avulsion fracture (Figure 2) occur most commonly in skeletally immature individuals between the ages of 8 and 14 years. Patients with ACL avulsion fractures will develop knee hemarthrosis within 12–16 hours, and inability to walk and run in the days/weeks after the injury. In order to survive, EQH-3 had to rely on help from members of his group shortly after the injury occurred. After the acute stage is over, in the month and years after the injury, individual with ACL avulsion fractures can walk and run but might suffer from knee instability to bear weight (Perugia et al, 2009; Anderson and Anderson, 2015). If such pathology did occur in the knee of EQH-3 he might have suffered from instability of the left knee joint and therefor minimize weight bearing on the left leg. The small articular surface of the distal femur might be the result of that pathology as articular surface area directly related to the amount of axial pressure exerted on the joint.
Results
Our results show that the unique morphology of the knee joint of EQH-3 is different from the morphology of the knee joints modern humans and other hominin specimens (Table 1). Thus, the first and second hypotheses should be rejected. The narrow intercondylar notch might indeed be a result of taphonomy- but taphonomy cannot be the cause for the small articular condyles or the protruding intercondylar eminence. Accordingly, the third hypothesis should be also partially rejected.
The medial intercondylar eminence is the attachment area for the anterior cruciate ligament (ACL), one of the four major ligaments that stabilize the knee joint.
Literature cited:
References:
Been E, Levin L, Barzilai O, Ekshtain R, Mallinsky-Buller A,Greenbaum N, Agha N, Rak Y, Hovers E. (2015) Human Remains from the Late Middle Paleolithic Open-Air Site of ’Ein Qashish, Yizra’el Valley, Israel. European Society for the study of Human Evolution.
Anderson AF, & Anderson CN. (2015). Correlation of meniscal and articular cartilage injuries in children and adolescents with timing of anterior cruciate ligament reconstruction. The American journal of sports medicine, 43(2),
Perugia D, Basiglini L, Vadala A, & Ferretti A. (2009). Clinical and radiological results of arthroscopically treated tibial spine fractures in childhood. International orthopaedics, 33(1),