Sensory nerves only temporarily protect the unstable canine knee joint from osteoarthritis. Evidence that sensory nerves reprogram the central nervous system after cruciate ligament transection.
OBJECTIVE
The slow rate at which articular cartilage degrades in dogs after transection of the anterior cruciate ligament (ACLT) has been attributed to capsular thickening and buttressing by osteophytes. We investigated the roles of the peripheral and central nervous systems in protecting knee joints with chronic ACL deficiency from breakdown.


METHODS
Five groups of dogs were studied; all were killed 72 weeks after left knee surgery. Group A had ACLT, group B had ACLT followed 52 weeks later by ipsilateral L4-S1 dorsal root ganglionectomy (DRG), group C had DRG followed 2 weeks later by ACLT, group D had sham DRG followed 2 weeks later by ACLT, and group E had DRG followed 2 weeks later by sham ACTL.


RESULTS
Group E dogs did not develop knee pathology. All cruciate-deficient knees were lax at the end of the study. The osteoarthritis (OA) that developed in groups A, B, and D was comparable (P > 0.05), and was significantly greater than that in group E (P < 0.05). Group C developed much more severe OA than any of the other groups (P < 0.05).


CONCLUSIONS
Ipsilateral sensory input is temporarily important in protecting the unstable joint from rapid breakdown. Over time, the central nervous system apparently acquires the ability to protect the unstable joint without continued ipsilateral sensory input.
O'Connor
B L
BL
Department of Anatomy, Indiana University School of Medicine, Indiana University Multipurpose Arthritis and Musculoskeletal Disease Center, Indianapolis.
Visco
D M
DM
Brandt
K D
KD
Albrecht
M
M
O'Connor
A B
AB
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D002358:Cartilage, Articular / Q000737:chemistry / Q000473:pathology*; D004195:Disease Models, Animal; D004285:Dogs; D005269:Femur / Q000473:pathology*; D005727:Ganglia, Spinal / Q000601:surgery; D015171:Ganglionectomy; D007593:Joint Instability / Q000473:pathology* / Q000503:physiopathology; D007719:Knee Joint / Q000294:innervation / Q000503:physiopathology*; D008124:Locomotion / Q000502:physiology*; D008297:Male; D010003:Osteoarthritis / Q000503:physiopathology*; D012018:Reflex; D014574:Uronic Acids / Q000032:analysis
D014574:Uronic Acids