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

BACKGROUND: Numerous 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. METHODS: In 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. RESULTS: No 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. CONCLUSIONS: Using 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

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

Background The design of the Exeter stem may facilitate distal migration, but radiostereometric analysis (RSA) studies have been limited to 2 years of follow-up. Patients and methods We followed migration of the Exeter femoral stems in 22 primary hip arthroplasties for 5 years with RSA. Results All stems migrated distally and the median migration at 2 years was 1.34 mm, while at 5 years it was 1.77 mm. 7 stems migrated above accuracy between 3 and 5 years. (RSA) evaluation of the cement mantle could be performed in 14 cases, and in 5 slight migration was found. Most of the stems rotated towards retroversion and the median rotation at 2 years was 1.2°, while at 5 years it was 1.6°. We found 1 patient with impending clinical failure but no deviation in the RSA migration pattern, and 1 patient with unstable migration pattern but no clinical symptoms. Interpretation We found a greater distal migration of the Exeter stem for longer periods of time than seen with other types of cemented implants

Hip revision using the Exeter stem, impacted morselized allograft bone and cement: A consecutive 5-year radiostereometric and radiographic study in 15 hips

Background: Impaction grafting in hip revision surgery is widely used but studies with mid- and long-term follow-up are scarce. Patients, methods and results A 5-year radiostereometric (RSA) follow-up of 15 hip revisions with the Exeter stem, morselized impacted allograft bone and cement revealed that 3 stems had not migrated between 2 and 5 years after revision, 11 stems had migrated to a minor degree in at least 1 direction, and 1 stem was loose according to RSA but without any radiographic signs of loosening or pain. The pain score was comparable to primary arthroplasties. Interpretation From a 5-year perspective, first-time hip revisions for aseptic loosening with impacted morselized allograft bone and cement appear to yield good clinical results, although stem migration continues to a minor degree 2 years after revision

Surgical treatment of symptomatic recurrent disc herniation

The official publication of the International Society for the Study of the Lumbar Spine, this volume is the most authoritative and up-to-date reference on the lumbar spine. This edition provides more balance between basic science and clinical material and has been completely reorganized for easy reference. New chapters cover gene therapy, outcomes assessment, and alternatives to traditional nonoperative treatment. The editors have also added chapters on preparation for surgery, surgical approaches, spinal instrumentation, and bone grafts. Chapters on specific disorders have a consistent structure—definition, natural history, physical examination, imaging, nonoperative treatment, operative treatment, postoperative management, results of surgery, and complications

Mechanics of the external fixation test in the lumbar spine. A roentgen stereophotogrammetric analysis

STUDY DESIGN: By implanting tantalum indicators percutaneously during application of pedicular screws, lumbosacral mobility could be studied with roentgen stereophotogrammetric analysis in seven patients having a diagnostic external fixation test. OBJECTIVES: To determine the mechanical effects on the segmental mobility during an external fixation test of the lumbar spine. SUMMARY OF BACKGROUND DATA: External pedicular fixation test of the lumbar spine has been reported a valuable prognostic instrument in fusion for low back pain. METHODS: A Magerl external fixation device was applied in seven patients with low-grade spondylolysis-olisthesis. By using roentgen stereophotogrammetric technique, the intervertebral translations in the lumbosacral segment were determined. Each patient had three separate examinations; with the frame fixed, with the frame loosened, and without frame 6 weeks after screw removal. RESULTS: With the external frame fixed, the sagittal intervertebral translations were significantly reduced, in three cases to a level beneath the accuracy of the measuring method. One patient had the same immobilizing effect even with the frame loosened while for the others loosening of the frame meant regained mobility of the segment. CONCLUSION: The properties of the external fixator give an adequate mechanical basis for the prognostic external fixation test in lumbar fusion

Randomized radio stereometric 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 radiosterometric 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 0.5degrees to 2.0degrees. 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

Radial tunnel release. Unpredictable outcome in 37 consecutive cases with a 1-5 year follow-up

37 consecutive patients with radial tunnel syndrome treated by decompression of the posterior interosseous nerve and application of a free fat transplant were retrospectively evaluated 3.5 (1-5) years post-operatively by an independent observer. Substantial pain relief was reported by 13 patients and 15 patients were satisfied with the outcome. 16 of 35 patients returned to their preoperative employment. There were complications in 12 cases, including two radial nerve pareses. Preoperative and operative findings did not correlate to the outcome. Judging from this study, the symptoms and signs used as diagnostic criteria for radial tunnel syndrome may be unreliable and the results of posterior interosseous nerve decompression unpredictable