A n 18-year-old man who presented with weakness in his lower limbs, had an upper motor neurone lesion at the D12-L1 level. At laminectomy two stone-like objects were found which proved to be bundles of tiny pieces of wood. They are thought to have entered the cord through an abdominal penetrating injury sustained six years previously.J Bone Joint Surg [Br] 2000;82-B:267-8. Received 14 April 1999; Accepted 24 June 1999 We describe a patient with a foreign body resembling a 'stone' in the spinal cord. Details of the probable aetiology and pathogenesis are given. Case reportAn 18-year-old man presented with difficulty in walking due to weakness of his lower limbs which had been present for six months and had become progressively worse. He had had difficulty in passing urine for 15 days. There was no pyrexia or constitutional symptoms. On examination he had an upper motor neurone lesion corresponding to the level of D11.Six years previously he had fallen from a tree in a field and landed on sharp shoots which were remnants of the cut stems of sugar cane. He sustained a penetrating injury of the abdomen. An exploratory laparotomy had been carried out. He had an associated compression fracture in the dorsolumbar region. He recovered in six weeks and was well for six years.Examination revealed a kyphotic deformity of the dorsolumbar spine. He had upper motor neurone paraparesis with grade-3 power at the hip, knee and ankles and grade-2 power of extensor hallucis longus and flexor hallucis longus. He had hypoaesthesia in the L2, L3 and L4 dermatomes and loss of proprioception.Routine haematological investigations were normal. The Mantoux test was negative. Plain radiographs showed wedging at the level of D11 and 12 with posterior scalloping and a widened interpedicular distance at these levels. MRI and CT were not done.Myelography revealed total obstruction at L1 with widening of the dye column, consistent with an intradural lesion (Fig. 1). Examination of the CSF showed xanthochromia. In view of the clinical and myelographic diagnosis of obstruction at L1, the patient had a spinal decompression and a laminectomy from D11 to L2. The ligamentum flavum was hypertrophied. It was dirty yellow in colour with a firm fusiform swelling. The dura was adherent from D11 to L1. An incision was made in the thickened dura but there was no leakage of CSF. There was a solid mass of tissue and, with difficulty, a plane of cleavage was developed with blunt dissection to expose the swelling. Two black, rounded hard structures were encountered which were stone-like and surrounded by a foreignbody granuloma (Fig. 2a). They were excised and produced a metallic sound when dropped into a steel container. The

The purpose of this study was to evaluate the result of lateral retinacular release in patellar compression syndrome, which is a painful compression syndrome arthropathy of the lateral facet of the patella.187 knees of 120 patients, were included in this study. The criteria for inclusion were the presence of complaints of anterior knee pain without instability. Clinical signs pointing to lateral retinacular tightness and radiological evidence of lateral patellar tilt with minimal subluxation in 187 knees of 120 patients,130 knees were treated conservatively and 56 knees of 33 patients operatively by lateral retinacular release, those patients were selected after they failed to respond to a minimum of 3 months of conservative treatment that entailed isometric quadriceps strengthening exercises, restrictions of activities that requires prolonged knee flexion and administration of antiinflammatory agents the lateral retinacular release was performed through a 3 centimeter skin incision. A satisfactory result was achieved in over75% cases. The complication rate was low or negligible. No complications of haemarthroses w as found postoperatively. The data indicated that better results can be achieved in patients who have patellar tightness, lateral Para patellar tenderness, a positive medial patellar glide test and positive medial apprehension test. Poor results are to be expected in patients with severe arthritic changes involving the lateral patellar facet.