The motion of the shoulder complex, the scapulo-humero-thoracic rhythm, is an equilibrium between transmission of loads and positioning of the upper limb. This rhythm, which can be described by 12 spatial variables, is either responsible for, or affected by the genesis of shoulder pathology and trauma. Thus, imaging the articulations of the shoulder through a global range of motion is essential in aiding diagnosis, management decisions and interpreting operative outcome. As such, the objective of this study was to dynamically image the scapulo-humero-thoracic rhythm. The subjects were seated between the toroid of the scanner and maximally slewn table on a customised tripod which both protects the target rings and provides a degree of comfort. Each subject was asked to carryout 4 movements; adduction to abduction in the scapular plane, internal rotation to external rotation at 0° and 90° abduction and flexion to extension. Each movement was carried out over a period of 5 seconds, enabling the acquisition of 20 volumes per movement. Electron Beam Computed Tomography (EBCT) enables the scanning of a number of contiguous slices, each taking 50 msec. Previously this has facilitated real-time imaging and rendering of both cardiopulmonary function and colonography. A GE Imatron EBCT C300 scanner was used with a multislice sequence imaging protocol to collect 8 transaxial slices per volume by sweeping an x-ray beam sequentially over 4 tungsten target rings and recording x-ray intensity via two fixed detector rings after the reflected beam passes through the body. Each slice was post-processed by semi-automatic segmention using Amira software, and reconstructed to produce three-dimensional volumes of the humerus, scapula, clavicle and selected ribs. Anatomical landmarks were then identified and the normal rhythm of the shoulder was described. In conclusion, EBCT provides a quick and efficient method for direct realtime dynamic imaging of the shoulder girdle under normal conditions, the first time this has been achieved to the best of our knowledge. Not only do these reconstructions provide further input matter for preexisting and future computational shoulder models, but estabilishes an initial baseline for further clinical experience. As such, we hypothesise the ability of this modalitiy to image pathological and traumatic disruption to shoulder rhythm. The potential clinical application of this tool would include imaging of traumatic instability and impingement, facilitated by some minor ergonomic alterations to the apparatus.
The scapulo-humerothoracic rhythm, which can be described by up to 12 spatial variables, is either responsible for, or affected by the genesis of shoulder pathology and trauma, and therefore, imaging the articulations of the shoulder through a global range of motion is desirable in aiding the diagnosis and management of both movement deficiency and osseous lesions. 4 control volunteers were seated between the toroid of the scanner and maximally slewn table on a customised tripod. The subjects were asked to carryout a sequence of defined movements, each over a period of 5 seconds. These included adduction to abduction in the scapular plane, internal rotation to external rotation at 0° and 90° abduction and flexion to extension. An EBCT C300 scanner was used with a multislice sequence imaging protocol to collect 8 transaxial slices per volume by sweeping an x-ray beam sequentially over 4 tungsten target rings and recording x-ray intensity via two fixed detector rings after the reflected beam passes through the body, enabling the acquisition of 20 volumes per movement with minimal radiation exposure. Each slice was post-processed by semi-automatic segmentation using Amira software, and reconstructed to produce three-dimensional reconstructions. Following this, a kinematic description of the joint complex was developed using SIMM, enabling quantification of up to 5 Degrees of Freedom at the Glenohumeral joint. EBCT provides a quick and efficient method for direct real-time dynamic imaging of the shoulder girdle, although currently crude. As such, we hypothesis the ability of EBCT to image traumatic disruption to shoulder rhythm, and are currently pursuing this work. These reconstructions promise great potential for further clinical experience and quantitative analysis of small translations aided by achievable limited technological refinement of the modality.
Between 1980 and 1988, displacement bone-marrow transplantation was performed on 25 children with Hurler's syndrome (type-1 mucopolysaccharidosis). We describe the musculoskeletal development of 11 of the 12 surviving children and the orthopaedic procedures undertaken to treat progressive thoracolumbar kyphosis, hip subluxation and carpal tunnel syndrome. We found abnormal bone modelling, focal failures of ossification and an avascular disorder of the femoral head in every patient and offer an explanation for these phenomena. Increasing valgus deformity of the knees and progressive generalised myopathy caused loss of mobility as the children entered adolescence. The benefit of bone-marrow transplantation as a treatment for the skeletal disorders of Hurler's syndrome is limited by the poor penetration of the musculoskeletal tissues by the enzyme derived from the leucocytes.
Fifty-two children with 62 discoid lateral menisci were reviewed at an average follow-up of 5.5 years. Their average age at operation was 10.5 years and the mean delay in diagnosis was 24 months. Most of the children had vague and intermittent symptoms and the classical clunk was demonstrable in only 39% of the knees. An associated osteochondritis dissecans of the lateral femoral condyle was seen in seven knees. Forty-eight knees with symptomatic torn discoid menisci underwent open total lateral meniscectomy, six had arthroscopic partial meniscectomy and eight knees with intact discoid menisci, were left alone. Based on Ikeuchi's grading (Ikeuchi 1982), 37% of the knees had an excellent result, 47% had a good result and 16% had a fair result: none was poor. Arthroscopic partial meniscectomy is recommended only when the posterior attachment of the discoid meniscus is stable. A total meniscectomy is indicated for the Wrisberg-ligament type of discoid meniscus with posterior instability.
Twenty-two knees with osteochondritis dissecans diagnosed before skeletal maturity were followed prospectively into middle age: 32% had radiographic evidence of moderate or severe osteoarthritis at an average follow-up of 33.6 years; only half had a good or excellent functional result. We found that osteoarthritis was more likely to occur if the defect was large or affected the lateral femoral condyle.
Ten epiphyses in seven children underwent fixed-rate distraction of 0.25 mm twice daily in an attempt to achieve percutaneous leg lengthening by chondrodiatasis. The forces generated across the growth plate were recorded by means of strain gauges incorporated into the distractors. All epiphyses fractured before 33 days of lengthening. An average gain of 6.75 cm was achieved. Epiphyseal distraction at the lower femur produced many complications, but at the upper tibial epiphysis planned lengthening was achieved, with excellent bone production and few complications.
We reviewed 230 patients an average of 34 months after they had undergone partial or total meniscectomy by surgeons of different experience in a busy unit. Open and arthroscopic meniscectomies were compared. Arthroscopic partial meniscectomy resulted in a significant reduction of inpatient stay and earlier return to work and sport. Analysis of the type of meniscal damage showed that arthroscopic removal of "bucket handles" achieved better results than open techniques. Comparatively poor results were found for lateral meniscectomy.
The clinical and radiological features of 12 knees (10 patients) with congenital absence of the anterior cruciate ligament are presented. The high frequency of this condition in association with other more easily recognised congenital abnormalities of the knee is discussed. It is concluded that congenital absence of the anterior cruciate ligament is more common than generally suspected and is associated with other developmental abnormalities of both bone and soft tissue in the lower limb, particularly around the knee joint.
1. Destructive changes in a knee joint, eventually requiring arthrodesis, are reported in a patient who had undergone renal transplantation. 2. The underlying pathology was avascular necrosis with separation of large osteochondral fragments. 3. The pathogenesis is discussed.
1. In sixty mature rabbits osteochondral fractures of various types were made in the medial femoral condyle. 2. The fractures or fragments which remained stable united but those in which movement occurred progressed to non-union. 3. An ununited osteochondral fragment resembled osteochondritis dissecans in the human both radiologically and histologically. 4. Experiments in the cadaveric knee show that the patella articulates with the classical site on the intercondylar aspect of the medial femoral condyle in full flexion of the joint and here an osteochondral fracture could be sustained. 5. It is concluded that the fragment in osteochondritis dissecans follows an osteochondral fracture which remains ununited.
1. One hundred patients with osteochondritis dissecans of the knee have been reviewed. Sixty-eight were male. Unilateral lesions were found in seventy-four. The average age at onset of symptoms was eighteen years. 2. The outstanding etiological feature was found to be direct injury to the joint surface (46 percent), repeated injuries sustained in first class athletics and field sports, and mechanical abnormalities of the knee. 3. Osteochondral fracture was found in seven cases. 4. The results of various types of treatment are described and a plan of management outlined.
