Ragnar Johnsson

Randomized Radiostereometric Study Comparing Osteogenic Protein-1 (BMP-7) and Autograft Bone in Human Noninstrumented Posterolateral Lumbar Fusion : 2002 Volvo Award in Clinical Studies

Study Design. Randomized efficacy trial comparing two types of noninstrumented posterolateral fusion between L5 and S1 in patients with L5 spondylolysis and vertebral slip less than 50%, as evaluated by radiostereometric analysis. Objective. To determine whether osteogenic protein-1 (BMP-7) in the OP-1 Implant yields better stabilizing bony fusion than autograft bone. Summary of Background Data. Animal studies of osteoinductive proteins in noninstrumented posterolateral fusions have shown high fusion rates. No similar conclusive study on humans has been performed. Methods. For this study, 20 patients were randomized to fusion with either OP-1 Implant or autograft bone from the iliac crest, 10 in each group. The patients were instructed to keep the trunk straight for 5 months after surgery with the aid of a soft lumbar brace. At surgery 0.8-mm metallic markers were positioned in L5 and the sacrum, enabling radiostereometric follow-up analysis during 1 year. The three-dimensional vertebral movements, as measured by radiostereometric analysis induced by positional change from supine posture to standing and sitting, were calculated with an accuracy of 0.5 to 0.7 mm and 0.5° to 2.0°. Conventional radiography was added. Results. No significant difference was noted between the radiostereometric and radiographic results of fusion with the OP-1 Implant and fusion with autograft bone. There was a significant relation between reduced vertebral movements and better bone formation. No adverse effects of the OP-1 Implant occurred. Persistent minor pain at the iliac crest was noticed in one patient. Conclusions. There was no significant difference between the two fusion versions. Thus, the OP-1 Implant did not yield better stabilizing bony fusion than autograft bone.

Outcomes of endoscopic surgery compared with open surgery for carpal tunnel syndrome among employed patients: randomised controlled trial

Abstract Objectives To compare endoscopic and open carpal tunnel release surgery among employed patients with carpal tunnel syndrome. Design and setting Randomised controlled trial at a single orthopaedic department. Participants 128 employed patients aged 25-60 years with clinically diagnosed and electrophysiologically confirmed idiopathic carpal tunnel syndrome. Main outcome measures The primary outcome was severity of postoperative pain in the scar or proximal palm and the degree to which pain or tenderness limits activities, each rated on a 4 point scale, transformed into a combined score of 0 (none) to 100 (severe pain or tenderness causing severe activity limitation). The secondary outcomes were length of postoperative work absence, severity of symptoms of carpal tunnel syndrome and functional status scores, SF-12 quality of life score, and hand sensation and strength (blinded examiner); follow-up at three and six weeks and three and 12 months. Results 63 patients were allocated to endoscopic surgery and 65 patients to open surgery, with no withdrawals or dropouts. Pain in the scar or proximal palm was less prevalent or severe after endoscopic surgery than after open surgery but the differences were generally small. At three months, pain in the scar or palm was reported by 33 patients (52%) in the endoscopic group and 53 patients (82%) in the open group (number needed to treat 3.4, 95% confidence interval 2.3 to 7.7) and the mean score difference for severity of pain in scar or palm and limitation of activity was 13.3 (5.3 to 21.3). No differences between the groups were found in the other outcomes. The median length of work absence after surgery was 28 days in both groups. Quality of life measures improved substantially. Conclusions In carpal tunnel syndrome, endoscopic surgery was associated with less postoperative pain than open surgery, but the small size of the benefit and similarity in other outcomes make its cost effectiveness uncertain.

Movement pattern of the Exeter femoral stem: A radiostereometric analysis of 22 primary hip arthroplasties followed for 5 years

Background It is difficult to assess the orientation of the acetabular component on routine radiographs. We present a method for determining the spatial orientation of the acetabular component after total hip arthroplasty (THA) using computed tomography.Patients and methods Two CT-scans, 10 min apart, were obtained from each of 10 patients after THA. Using locally developed software, two independent examiners measured the orientation of the acetabular component in relation to the pelvis. The measurements were repeated after one week. To be independent of the patient position during scanning, the method involved two steps. Firstly, a 3D volumetric image of the pelvis was brought into a standard pelvic orientation, then the orientation of the acetabular component was measured. The orientation of the acetabular component was expressed as operative anteversion and inclination relative to an internal pelvic reference coordinate system. To evaluate precision, we compared measurements across pairs of CT volumes between observers and trials.Results Mean absolute interobserver angle error was 2.3° for anteversion (range 0–6.6°), and 1.1° for inclination (range 0–4.6°). For interobserver measurements, the precision, defined as one standard deviation, was 2.9° for anteversion, and 1.5° for inclination. A Students t-test showed that the overall differences between the examiners, trials, and cases were not significant. Data were normally distributed and were not dependent on examiner or trial.Interpretation We conclude that the implant angles of the acetabular component in relation to the pelvis could be detected repeatedly using CT, independently of patient positioning.

Manipulation Does Not Alter the Position of the Sacroiliac Joint: A Roentgen Stereophotogrammetric Analysis

Study Design. A roentgen stereophotogrammetric analysis study of patients with sacroiliac joint dysfunction. Objectives. To investigate whether manipulation can influence the position between the ilium and the sacrum, and whether positional tests for the sacroiliac joint are valid. Summary of Background Data. Sacroiliac joint dysfunction is a subject of controversy. The validity of different sacroiliac joint tests is unknown. Long‐standing therapeutic tradition is to manipulate supposed dysfunctions of the sacroiliac joint. Many manual therapists claim that their good clinical results are a consequence of a reduction of subluxation. Methods. Ten patients with symptoms and sacroiliac joint tests results indicating unilateral sacroiliac joint dysfunction were recruited. Twelve sacroiliac joint tests were chosen. The results of most of these tests were required to be positive before manipulation and normalized after manipulation. Roentgen stereophotogrammetric analysis was performed with the patient in the standing position, before and after treatment. Results. In none of the 10 patients did manipulation alter the position of the sacrum in relation to the ilium, defined by roentgen stereophotogrammetric analysis. Positional test results changed from positive before manipulation to normal after. Conclusions. Manipulation of the sacroiliac joint normalized different types of clinical test results but was not accompanied by altered position of the sacroiliac joint, according to roentgen stereophotogrammetric analysis. Therefore, the positional test results were not valid. However, the current results neither disprove nor prove possible beneficial clinical effects achieved by manipulation of the sacroiliac joint. Because the supposed positive effects are not a result of a reduction of subluxation, further studies of the effects of manipulation should focus on the soft tissue response.

The spondylolytic vertebra and its adjacent segment. Mobility measured before and after posterolateral fusion

Study Design. By using roentgen stereophotogrammetric analysis in six patients having tantalum indicators implanted at a preoperative external fixation test, the mobility in the spondylolytic lumbosacral level and its adjacent segment could be studied before fusion and during the course of postoperative fusion consolidation. Objective. To study the mobility effects on the segment adjacent to a lumbar fusion over time from the preoperative situation until fusion healing as defined by roentgen stereophotogrammetric analysis. Summary of Background Data. In vitro studies indicate that the altered biomechanical situation after lumbar fusion increases the intradiscal pressure and changes the kinematics in the juxtafused segment. Methods. Six patients with low grade spondylolysis‐olisthesis were scheduled for fusion of the spondylolytic lumbosacral segment after a preoperative external fixation test. The latter procedure also included implantation of tantalum markers for spinal roentgen stereophotogrammetric analysis. Each patient was examined by roentgen stereophotogrammetric analysis at four separate occasions: before fusion (2 months after removal of the external frame) and 3, 6, and 12 months after surgery. The translatory movements of the L5 vertebra in relation to sacrum and of the L4 vertebra in relation to the L5 vertebra were calculated at each examination. Results. For the juxtafused L4‐L5 level, increased and decreased mobility patterns could be identified. Transformation of the preoperative mobility in the lumbosacral segment to the adjacent segment during fusion consolidation was verified in two patients but was not a general phenomenon. Conclusion. Fusion of the lumbosacral segment can alter the kinematics of the adjacent segment, redistributing the mobility toward relative hypermobility in the juxtafused segment.

Effect of lumbar orthosis on intervertebral mobility. A roentgen stereophotogrammetric analysis

To determine the stabilizing effect of external lumbar supports on the intervertebral mobility in the lower lumbar spine, seven patients with a posterolateral lumbosacral fusion without internal fixation were examined by roentgen stereophotogrammetric analysis in supine and erect positions 1 month after surgery, that is, after soft tissue healing but before fusion consolidation. Each patient was examined without lumber support, with a molded, rigid orthosis and with a canvas corset with molded, plastic posterior support. Neither of the two types of lumber support had any stabilizing effect on the sagittal, vertical, or transverse intervertebral translations. This study using roentgen streophotogrammetric analysis confirms that lumbosacral orthosis has effect by restricting gross motions of the trunk rather than intervertebral mobility in the lumbar spine.

Mobility of the lower lumbar spine after posterolateral fusion determined by roentgen stereophotogrammetric analysis.

To determine the time-table for intervertebral stabilization after posterolateral fusion without osteosynthesis in the lower lumbar spine, 11 patients with no previous spinal surgery and with fusion due to spondylolysis-olisthesis Grade 1 to 2 or lumbar disc disorder/facet joint arthrosis were examined by roentgen stereophotogrammetric analysis (RSA) in supine and erect positions, and by conventional radiography for 1 year after surgery. In eight patients with osseous fusion radiographically, the sagittal and the vertical translations between the fused vertebral segments began to decrease after 3 to 6 months. However, the time for rigid fusion as defined by RSA varied between 3 months and 1 year, and in four patients sagittal/vertical translations of mostly less than 1 mm still persisted at 1 year postoperatively. In three patients with poor fusion radiographically, no rigid fusion as defined by RSA was obtained. Sagittal/vertical translations of 1 to 10 mm persisted at 1 year postoperatively in these patients. The preoperative pain disappeared in all patients except in one who had osseous fusion radiographically but persisting translations after 1 year.

Self-administered outcome instrument in carpal tunnel syndrome. Reliability, validity and responsiveness evaluated in 102 patients

We evaluated a Swedish version of a self-administered disease-specific outcome questionnaire for carpal tunnel syndrome regarding reliability, validity and responsiveness to clinical change. It consists of multi-item scales assessing symptom severity, function, patient satisfaction and quality of life. It was given to 102 patients before and 3 months after carpal tunnel release. Test-retest reliability, studied in a subsample of 22 patients on two occasions with a 1-3-week interval, showed good agreement between the scores. Internal consistency of the scales was high (Cronbach alpha 0.80-0.95). Validity of the scales was evaluated using the SF-36 general health questionnaire in a subgroup of 48 patients as well as items concerning patient satisfaction, showing the expected relationships between these measures. Responsiveness of the scales to clinical change, estimated by the effect size and standardized response mean, was large (0.94-1.7). We conclude that this questionnaire can provide a standardized measure of symptom severity and functional status, as well as patient satisfaction and quality of life in the carpal tunnel syndrome.

Early complications after one hundred and forty-four consecutive hip revisions with impacted morselized allograft bone and cement

Background: The use of impacted morselized allograft bone and cement in hip revision arthroplasty has been popular, but studies that specifically address intraoperative and postoperative complications have been scarce.Methods: All complications that occurred during, and within the first year after, 144 consecutive hip revision arthroplasties (108 stems and 130 sockets) performed with impacted morselized allograft bone and cement were recorded. Clinical and radiographic follow-up evaluation was performed at three months and at one year after surgery for all patients except eight (seven who had died of causes unrelated to the hip surgery and one who had sustained a stroke). Of these eight patients, seven had a six-week and/or three-month follow-up evaluation.Results: Thirty-nine femoral fractures occurred in thirty-seven hips; twenty-nine of the fractures occurred during surgery and ten, within five months after surgery. Of the intraoperative femoral fractures, twelve were proximal, nine were diaphyseal, and eight involved the greater trochanter. Of the postoperative femoral fractures, one was proximal and nine were diaphyseal. Other intraoperative complications were the creation of a femoral cortical window in seven hips and incidental perforation of the femoral cortex in fourteen. Multivariate analysis showed the risk factors for femoral fracture during or after revision to be concomitant disease, greater deficiency of the femoral bone stock, and an intraoperative femoral window or perforation. Other complications included dislocation of the femoral head in nine hips, deep infection in one hip, persistence of preoperative deep infection in one hip, and superficial wound infection requiring wound débridement in two hips.Conclusions: We found the complication rate to be high after hip revision arthroplasty performed with impacted morselized allograft bone and cement. The most serious complication was postoperative diaphyseal femoral fracture.

Diagnostic properties of nerve conduction tests in population-based carpal tunnel syndrome.

BackgroundNumerous nerve conduction tests are used for the electrodiagnosis of carpal tunnel syndrome (CTS), with a wide range of sensitivity and specificity reported for each test in clinical studies. The tests have not been assessed in population-based studies. Such information would be important when using electrodiagnosis in epidemiologic research. The purpose of this study was to compare the diagnostic accuracy of various nerve conduction tests in population-based CTS and determine the properties of the most accurate test.MethodsIn a population-based study a questionnaire was mailed to a random sample of 3,000 persons. Of 2,466 responders, 262 symptomatic (numbness/tingling in the radial fingers) and 125 randomly selected asymptomatic responders underwent clinical and electrophysiologic examinations. A standardized hand diagram was administered to the symptomatic persons. At the clinical examination, the examining surgeon identified 94 symptomatic persons as having clinically certain CTS. Nerve conduction tests were then performed on the symptomatic and the asymptomatic persons by blinded examiners. Analysis with receiver operating characteristic (ROC) curves was used to compare the diagnostic accuracy of the nerve conduction tests in distinguishing the persons with clinically certain CTS from the asymptomatic persons.ResultsNo difference was shown in the diagnostic accuracy of median nerve distal motor latency, digit-wrist sensory latency, wrist-palm sensory conduction velocity, and wrist-palm/forearm sensory conduction velocity ratio (area under curve, 0.75–0.76). Median-ulnar digit-wrist sensory latency difference had a significantly higher diagnostic accuracy (area under curve, 0.80). Using the optimal cutoff value of 0.8 ms for abnormal sensory latency difference shown on the ROC curve the sensitivity was 70%, specificity 82%, positive predictive value 19% and negative predictive value 98%. Based on the clinical diagnosis among the symptomatic persons, the hand diagram (classified as classic/probable or possible/unlikely CTS) had high sensitivity but poor specificity.ConclusionsUsing the clinical diagnosis of CTS as the criterion standard, nerve conduction tests had moderate sensitivity and specificity and a low positive predictive value in population-based CTS. Measurement of median-ulnar sensory latency difference had the highest diagnostic accuracy. The performance of nerve conduction tests in population-based CTS does not necessarily apply to their performance in clinical settings.