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. (1976). Annals of the Rheumatic Diseases, 35,[127][128][129][130][131][132]. Vertebral end-plate lesions (Schmorl's nodes) in the dorsolumbar spine. The distribution of end-plate lesions (Schmorl's nodes) and their relationship to bone density and disc degeneration have been studied in 50 post-mortem spines below D9 in subjects aged 13-96 years. Lesions were present in 76 % of cases with a predominance in males. They were found more frequently in the lower than in the upper vertebral end-plate. They were also more common and more severe in the dorsolumbar (DIO-LL) region than in the lower lumbar (L2-L5 region). In adults they were unrelated to age and bone density. Lesions were significantly related to disc degeneration in the DIO-L1 region but not in the L2-L5 region. It is suggested that end-plate lesions arising in adolescence (or before) may predispose the dorsolumbar spine to disc degeneration in later life.Since Schmorl (1927) and Putschar (1927) independently described the lesions variously known as Schmorl's nodes, cartilaginous nodes, intraspongious discal herniae (and here referred to as end-plate lesions-EPL), they have received little attention. Their pathogenesis is uncertain, and we remain ignorant of their relationships to other structural defects of the spine and to overall spinal function. We have therefore undertaken a systematic study of the spine below D9, and here report our findings on the distribution of EPL and their relationship to disc degeneration (DD) and bone density. Material and methodsFifty post-mortem specimens of the whole spine below D9 together with the sacrum have been studied. Subjects with neoplastic disease, gross osteoporotic vertebral collapse, and those who had received prolonged corticosteroid therapy were excluded. The age range was 13-96 years. There were 33 males (mean age 51-6 years) and 17 females (mean age 48-3 years). In each case undecalcified sections of a sacral bone block were examined for Paget's disease, osteomalacia, and other occult bone diseases except osteoporosis (see below). Only 3 subjects were found to be abnormal: a female aged 68 and a male aged 63 who had clinically unsuspected osteomalacia, and a male aged 42 who had moderately excessive osteoclastic bone resorption, probably secondary to renal disease. These three cases were not excluded because the findings in their spines tended to minimize rather than enhance the significance of the main conclusions of the study. BONE DENSITYVertebral bone density was assessed by measuring the weight/volume ratio of a complete central sagittal slab of the 3rd lumbar vertebra. After maceration the specimen was dried to constant weight in vacuo over phosphorus pentoxide. It was then embedded in wax and its volume measured using a pyknometer after the method ofAtkinson and Woodhead (1968).EPL AND DD (Figs. 1 and 2) After removing the neural arches the vertebral bodies were divided into five sagittal slabs. Radiographs of these were graded for EPL and DD by two of the authors working together. Discs were iden...

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SUMMARY As part of a systematic study of the spine between DlI and SI the response to stress has been assessed by measuring radiologically the total and segmental mobility of 103 specimens.The method was shown to be reproducible to within 10o% of total mobility. No (Elward, 1939;Gianturco, 1944;Tanz, 1953; Allbrook, 1957;Israel, 1959;Jonck and Van Niekerk, 1961; Clayson et al., 1962; Lindahl, 1966;Loebl, 1967;Sturrock et al., 1973;Sweetman et al., 1974). Post-mortem studies of dorsolumbar mobility have been neglected despite the advantage that they facilitate analysis of mobility patterns and their relation to structural abnormalities.The measurements of sagittal mobility described in this paper were obtained as part of a systemic study of the spine below D9. Material and methodsThe material consisted of 117 selected post-mortem specimens of the lower spine. Specimens were not removed from patients with known neoplasia or metabolic bone disease or if they had received longterm corticosteroids. Histological examination of an undecalcified bone block from the sacrum of each spine revealed 5 patients with unsuspected osteomalacia and 1 with mild secondary hyperparathyroidism. These patients were not included in the Accepted for publication 7 August 1978 Correspondence to Dr R. C. Hilton, Rheumatic Diseases Unit, Hope Hospital, Eccles Old Road, Salford M6 8HD. study. Of the remaining 111, 52 were females and 59 were males. The age range was 13 to 96 years. Fifty-three patients were under 50 years and 58 were over 50 years of age. Most patients had died within 1 week of admission to hospital, and none had been confined to bed for more than 1 month. MEASUREMENT OF SAGITTAL MOBILITYThe method used was an adaptation of that described by Ball and Meijers (1964) for mobility studies on the cervical spine. The lower spine, including the sacrum, was removed by dividing the ninth dorsal vertebra and the sacroiliac joints. Measurements were made at room temperature in a humid atmosphere. In most cases fresh specimens were used. The remainder were stored at 40C wrapped in several layers of gauze soaked in saline and brought to room temperature before measuring mobility. It has been shown that this storing procedure does not affect the mechanical properties (Kazarian, 1972). A steel pin was inserted into the anterior aspect of each vertebral body from D1O to S1 inclusive. The sacrum was fixed in a clamp with the spine and pins lying in the horizontal plane about 5 cm above the surface of a table. A line attached to D9 was led anteriorly over a pulley to a cloth bag containing a 2 kg load. This load was selected because preliminary experiments had shown that with greater loads there was a risk of fracture, especially in older specimens. In a few younger 378 on 30 April 2019 by guest. Protected by copyright.