Bo Sahlstedt’s research while affiliated with Uppsala University and other places

There is no consensus as to whether uncemented or cemented femoral stems should be used in younger patients. We compared the uncemented Cone stem to the cemented Bimetric stem in young patients with osteoarthritis. We randomized 45 relatively young patients (< 65 years old, mean age 54 years) with osteoarthritis to either an uncemented Cone stem or a cemented Bimetric stem. All patients were followed for 2 years. Outcome was assessed by the Merle d'Aubigné score, conventional radiography and repeated radio-stereometric analysis (RSA). We also followed 81 Cone stems for 8 (7-12) years with revision as endpoint. The clinical outcome was excellent. No patient had postoperative thigh pain. The migration was small. The Bimetric stem was stable during the whole observation period, while the Cone stem subsided and rotated to retroversion during the first 3 months post-operatively, and then remained stable. In the follow-up study of 81 Cone stems, 1 stem was revised. We conclude that both the cemented Bimetric stem and the uncemented Cone stem are stable and give excellent clinical results after 2 years in relatively young patients with osteoarthritis. Although designed for CDH hips, the Cone stem appears to be suitable also for patients with osteoarthitis.

To evaluate safety and efficacy of the Olerud Cervical Fixation System a one-year follow up study was done by an independent observer. There were 30 patients (14 women) with a mean age of 68 (37-85) years. Indications were rheumatoid arthritis in 10, spinal stenosis in 6, trauma in 6, metastases in 4, revisions in 3, and painful spondylotic deformity in one patient. Short fusions were performed in 8 patients and long fusions in 22. Four patients were fused to occiput. C1-C2 fusion was performed in 3 patients. Nineteen of the 20 still alive were evaluated at follow up. One patient was deliberately fused in hyperlordosis, in the rest the alignment was acceptable. Primary stabilization was achieved in all but one. 107 pedicle screws were used; one screw in Th2 was placed lateral to the pedicle. 42 subaxial transarticular screws were used. There were no complications related to these screws. One patient experienced a non-instrument related neurological deterioration. Two infections and one hematoma drainage healed on conservative treatment. Loss of fixation and non-union developed in 2 patients. Patients with metastasis or myelopathy due to rheumatoid arthritis carried a high mortality risk. The Olerud Cervical Spine Fixation System is versatile in posterior fixation of the cervical spine and has proven to be both safe and efficient.

We used the Wagner (1989) method in 31 hip revisions because of loosening with pronounced scalloping, which made a conventional revision unsuitable. The radiographs showed that within a few months new bone developed in the defects. In 5 cases, a new revision was necessary at an early stage, because of dislocation and/or subsidence. At follow-up after 3 (1.5-5) years, 21 of the remaining 26 hips were pain-free and 23 had almost full range of motion.

The role of conventional radiography and bone scintigraphy in predicting the outcome of Legg-Calvé-Perthes disease was investigated. The 75 children reviewed (86 hips) were followed up to the primary healing of the disease. The findings at conventional radiography (obtained at presentation, at the time of maximum capital head involvement, and at the end of the healing process of the disease) were compared to early bone scintigraphy features. Bone scintigraphy provided more accurate information concerning the extent of the necrotic process than initial radiographs. Moreover it could determine revascularization and consequently the stage of the disease. The methods was, however, unable to predict the outcome of the disease in some cases, particularly if it was performed late after the onset of symptoms. Conventional radiography provided important information about other parameters such as "head-at-risk" signs which facilitated treatment selection. Of these signs not only lateral subluxation but also metaphyseal changes strongly predispose to severe deformity of the hip joint.

In a long-term follow-up of 55 Marmor knee arthroplasties in patients with rheumatoid arthritis operated on between 1975 and 1977, the radiologically visible indicator wire was used to identify the position of the tibial components. The survival rate of the prostheses at 15 years was 0.71, and the revisions were evenly distributed over the observation period of 16 years. No significant relationship was found between the slope of the tibial components postoperatively and the survival of the prostheses. However, a postoperative valgus angle of the leg of 3 deg or more tended to increase the risk of revision (RH = 2.7, 95% CL = 0.8-8.9). The patient's sex, affected side or weight did not influence prosthesis survival.

In a prospective study of 22 patients (24 hips) with Legg-Calvé-Perthes disease (LCPD) the findings at conventional radiography, arthrography, bone scintigraphy and MR imaging, obtained at the time of diagnosis, were compared. MR was superior to conventional radiography and bone scintigraphy in the detection of the extent of involvement in the femoral head. Arthrography was as good as or better than MR imaging in determining the shape of the articular surfaces and the occurrence of lateral subluxation. Conventional radiography was less sensitive in identifying the degree of lateral subluxation and the extent of the necrosis in the femoral head. MR imaging provided anatomical and pathophysiological information about the extent and location of head involvement as well as the degree of lateral subluxation. Revascularisation was more clearly demonstrated with MR than with bone scintigraphy, irrespective of symptom duration.

In a prospective study of 22 patients (24 hips) with Legg-Calvé-Perthes disease (LCPD) the findings at conventional radiography, arthrography, bone scintigraphy and MR imaging, obtained at the time of diagnosis, were compared. MR was superior to conventional radiography and bone scintigraphy in the detection of the extent of involvement in the femoral head. Arthrography was as good as or better than MR imaging in determining the shape of the articular surfaces and the occurrence of lateral subluxation. Conventional radiography was less sensitive in identifying the degree of lateral subluxation and the extent of the necrosis in the femoral head. MR imaging provided anatomical and pathophysiological information about the extent and location of head involvement as well as the degree of lateral subluxation. Revascularisation was more clearly demonstrated with MR than with bone scintigraphy, irrespective of symptom duration.

The authors assessed the clinical and imaging findings and late outcome in 50 patients with whiplash-type neck distortions (17 men, 33 women, mean age 33 years). Early symptoms are neck pain, stiffness, and sometimes radiating pain; later bizarre symptomatology poses intricate clinical and medicolegal problems. Pathoanatomic studies indicate that soft tissue injuries may be overlooked. Repeated clinical and radiographic examinations (plain and flexion-extension radiograms and contrast magnetic resonance imaging evaluated with a new grading system); surgical findings; follow-up were performed after 1 and 5 years by an independent observer neurologist. Neck pain persisted in 24 patients; radiating pain developed within 6 weeks in 19 patients. Two patients with segmental instability had posterior fusions and complete pain relief. Eight patients with severe radiating pain and large disc protrusions on magnetic resonance had nine surgically confirmed fresh disc herniations. Discectomy and fusion alleviated pain in these patients, whereas symptoms largely persisted in the conservatively treated patients. A high incidence of discoligamentous injuries was found in whiplash-type distortions. Most patients with severe persisting radiating pain had large disc protrusions on MRI that were confirmed as herniations at surgery. Neck and radiating pain were alleviated by early disc excision and fusion.

We studied 22 cervical spines from traffic accident victims with fatal craniocerebral injuries (19 male victims and three female victims; mean age, 26 years). Two had parietal fractures, 20 had skull base fractures (seven ring fractures), and 16 had severe polytrauma. The spines with all soft tissues were frozen in situ and removed. Fine-focus specimen radiograms were taken in special views and evaluated by an expert orthopedic radiologist. The specimens were then cryosectioned, and all injuries were recorded at submillimeter intervals on high resolution film. Ten radiological fracture diagnoses were incorrect; six were false positive, and four were false negative. In the upper cervical spine, only one of 10 gross ligamentous disruptions was suspected on the radiograms. In the lower cervical spine, 198 lesions were missed on the radiograms: 77 facet joint and ligamentum flavum injuries, 77 uncovertebral, and 22 disc lesions. In two adolescents, eight cartilaginous end-plate avulsions of the discs were found. At second-look evaluation, only four of the 245 unrecognized bone and discoligamentous lesions were detected on the radiograms. All spines were injured. Multiple-level soft-tissue injuries were common.