Substance P innervation of lumbar spine facet joints.

Sixteen adult human lumbar spine facet joints were harvested from patients undergoing various lumbar spine procedures. Diagnoses included degenerative disc disease, adult spinal deformity, facet joint degenerative arthritis, and degenerative spondylolisthesis. Facet joints were processed for routine hematoxylin and eosin staining. Immunohistochemical analysis was performed using a monoclonal antibody to substance P. All facets grossly exhibited evidence of degenerative disease, including cartilage surface irregularity and fibrillation. Histological examination of facets obtained from patients with degenerative spinal conditions demonstrated erosion channels extending through the subchondral bone and calcified cartilage into the articular cartilage. Immunostaining showed the presence of substance P-positive nerve fibers within these erosion channels, and also within marrow spaces. The presence of substance P nerve fibers within subchondral bone of degenerative lumbar facet joints implicates this type of joint in the etiology of low back pain.

Isolated subtalar arthrodesis.

Forty-eight isolated subtalar arthrodeses in 44 patients with an average follow-up of 59.5 months were retrospectively reviewed. Original diagnoses included talocalcaneal coalition, healed calcaneal fracture with subtalar arthrosis, acquired flatfoot because of posterior tibial tendon dysfunction, degenerative subtalar arthrosis, subtalar instability, and psoriatic arthritis. Ninety-three percent of patients were very satisfied or satisfied with their treatment. Pain and function improved significantly, and the American Orthopaedic Foot and Ankle Society ankle-hindfoot score at follow-up was 89. There were six unsatisfactory results: three feet had calcaneal fractures and three were malpositioned. Union was achieved in all cases. Transverse tarsal motion was diminished by 40%, dorsiflexion by 30%, and plantarflexion by 9%. There was a 36% and 41% incidence of mild radiographic progression of arthrosis in the ankle and transverse tarsal joint, respectively. Isolated subtalar arthrodesis provided a highly successful result in the disease presented, and this study provides support for the use of a selected hindfoot fusion procedure for specific indications.

Double arthrodesis in the adult.

Twenty-four double arthrodeses (24 patients) were evaluated at an average of 56 months postoperatively. Sixteen arthrodeses were performed for adult acquired flatfoot attributable to posterior tibial tendon insufficiency (16 patients), and results were compared with the results of eight patients undergoing arthrodesis for other diagnoses. The overall satisfaction rate was 83%, with 76% of patients having good and excellent results. Considerable improvements were observed in pain and function indices, with similar outcomes observed in the patients with and without acquired flatfoot. However, complications were more frequent in the patients who had flatfoot deformities. Clinical deformity was corrected reliably and radiographic parameters confirmed correction of deformity. Progression of arthrosis in the surrounding joints was common, but most patients were asymptomatic. Talonavicular nonunion was the most frequent complication, occurring in four patients. Three of the patients underwent revision arthrodesis.

Cuboid stress fractures: a report of two cases.

Stress fractures of the tarsal cuboid are rare. The literature contains three reported cases. This report presents two additional cases. These two occurred in collegiate athletes, and mimicked peroneal tendonitis on presentation. History, physical examination, plain radiographs, and bone scan were used for diagnosis. Treatment consisted of immobilization and activity modification, with complete resolution of symptoms in both cases.

Innervation of the human knee joint by substance-P fibers.

Anterior knee pain is a frequent musculoskeletal complaint affecting all ages, both sexes, athletes, and nonathletes alike. Numerous theories have been proposed regarding its etiology including patellar malalignment, quadriceps insufficiency, subluxation, quadriceps muscle tightness, and chondral defects. However, the mechanism by which these factors produce this pain is not clear. Knowledge of the distribution of nociceptive nerve fibers around the knee would seem to provide insight in treating these painful conditions. Eleven human patellae--eight specimens from patients with degenerative patellofemoral disease and three normals--were evaluated. Immunohistochemical techniques using monoclonal antibody to substance-P were employed to identify nociceptive fibers. Substance-P is a nociceptive neurotransmitter found in afferent nerve fibers. Substance-P fibers were isolated in the retinaculum, fat pad, periosteum, and subchondral plate of patellae affected with degenerative disease. This study demonstrates that selective tracting of nociceptive pain fibers is possible around the knee both in soft tissue and, in some circumstances, bone. The subchondral plate of normal patellae did not demonstrate erosion channels, but those with chondral defects from degenerative disease did. Nociceptive fibers found in these defects may explain the origin of symptoms in some patients. The distribution of substance-P nerve fibers in the soft tissues around the knee suggests that denervation may be the mechanism by which surgical procedures for anterior knee pain produce favorable results.