A computer-assisted systematic quality monitoring method for cervical hip fracture radiography

BACKGROUND

A thorough quality analysis of radiologic performance is cumbersome. Instead, the prevalence of missed cervical hip fractures might be used as a quality indicator.

PURPOSE

To validate a computer-based quality study of cervical hip fracture radiography.

MATERIAL AND METHODS

True and false negative and positive hip trauma radiography during 6 years was assessed manually. Patients with two or more radiologic hip examinations before surgery were selected by computer analysis of the databases. The first of two preoperative examinations might constitute a missed fracture. These cases were reviewed.

RESULTS

Out of 1621 cervical hip fractures, manual perusal found 51 (3.1%) false negative radiographic diagnoses. Among approximately 14,000 radiographic hip examinations, there were 27 (0.2%) false positive diagnoses. Fifty-seven percent of false negative reports were occult fractures, the other diagnostic mistakes. There were no significant differences over the years. Diagnostic sensitivity was 96.9% and specificity 99.8%. Computer-assisted analysis with a time interval of at least 120 days between the first and the second radiographic examination discovered 39 of the 51 false negative reports.

CONCLUSION

Cervical hip trauma radiography has high sensitivity and specificity. With computer-assisted analysis, 76% of false negative reports were found.

Quality of life after hip revision with impaction bone grafting on a par with that 4 years after primary cemented arthroplasty

BACKGROUND

There have been few studies evaluating patient-reported quality of life outcomes after hip revision with impaction bone grafting.

PATIENTS AND METHODS

The inclusion criteria were aseptic loosening after primary arthroplasty performed for osteoarthrosis, and first-time revision with impacted morselized allograft bone and cemented Exeter stem. During a 4-year period, 35 patients were eligible and all were included. The Nottingham Health Profile (NHP) was completed by the patients and the Charnley hip scores recorded by the examining surgeon preoperatively, after 6 months and yearly up to 4 years (28 patients) postoperatively. For comparison, 35 osteoarthrotic patients completed the NHP 4 years after cemented Exeter primary arthroplasty.

RESULTS

At 4 years, the NHP scores for the revision patients did not differ significantly from those recorded in the primary arthroplasty group. Among the revision patients, mixed model analysis showed improvement in NHP pain (p < 0.001) and physical mobility scores (p = 0.002). The effect size at 4 years was large for pain (1.2) and moderate for physical mobility (0.6). The major improvement was recorded at 6 months, with no further substantial change observed. The correlations between the NHP and Charnley scores were weak or moderate (r, -0.15 to -0.67).

INTERPRETATION

Hip revision with impaction bone grafting leads to substantially improved quality of life, similar to that 4 years after primary arthroplasty.

Hip revision using the Exeter stem, impacted morselized allograft bone and cementA 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.

Open compared with 2-portal endoscopic carpal tunnel release: a 5-year follow-up of a randomized controlled trial

PURPOSE

The purpose of this investigation was to extend the previously reported short-term randomized trial of open and endoscopic carpal tunnel release in patients with carpal tunnel syndrome (CTS) to compare outcomes 5 years after surgery.

METHODS

In a single-center randomized controlled trial, 128 patients (25 to 60 years) with clinically diagnosed and electrophysiologically confirmed idiopathic CTS were randomized immediately before surgery to open or 2-portal endoscopic release. The outcome measures included the validated CTS questionnaire's symptom severity and functional status scales (scored from 1 to 5) completed at baseline and 1 year postoperatively. At the extended follow-up of the trial 5 years after surgery, 2 patients had died and the other 126 participants (63 patients in each group) completed the CTS questionnaire.

RESULTS

At the 5-year follow-up no difference between the groups was found in the CTS symptom severity score. The mean (SD) score in the open group was 1.42 (0.7) and in the endoscopic group was 1.45 (0.7), and the mean difference in score change from baseline was 0.03 (95% confidence interval, -0.21 to 0.27). Between 1 year and 5 years postoperatively, the CTS symptom severity score had deteriorated by at least 0.4 point in 9 patients in the open group and in 10 patients in the endoscopic group. The mean (SD) CTS functional status score was 1.29 (0.5) in the open group and 1.30 (0.5) in the endoscopic group. At 5 years, 11 patients in the open group and 10 patients in the endoscopic group reported persistent pain in the scar or proximal palm. Three patients in each group had repeat surgery on the operated hand because of persistent or recurrent symptoms.

CONCLUSIONS

The improvements in symptoms of CTS and hand-related disability 5 years after open and 2-portal endoscopic carpal tunnel release were equivalent.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

Carpal tunnel syndrome and keyboard use at work: a population-based study

OBJECTIVE

To investigate the relationship between carpal tunnel syndrome (CTS) and keyboard use at work in a general population.

METHODS

A health status questionnaire was mailed to 2,465 persons of working age (25-65 years) who were randomly selected from the general population of a representative region of Sweden. The questionnaire required the subjects to provide information about the presence and severity of pain, numbness and tingling in each body region, employment history, and work activities, including average time spent using a keyboard during a usual working day. Those reporting recurrent hand numbness or tingling in the median nerve distribution were asked to undergo a physical examination and nerve conduction testing. The prevalence of CTS, defined as symptoms plus abnormal results on nerve conduction tests, was compared between groups of subjects that differed in their intensity of keyboard use, adjusting for age, sex, body mass index, and smoking status.

RESULTS

Eighty-two percent responded to the questionnaire, and 80% of all symptomatic persons attended the examinations. Persons who had reported intensive keyboard use on the questionnaire were significantly less likely to be diagnosed as having CTS than were those who had reported little keyboard use, with a prevalence that increased from 2.6% in the highest keyboard use group (> or = 4 hours/day), to 2.9% in the moderate use group (1 to <4 hours/day), 4.9% in the low use group (<1 hour/day), and 5.2% in the no keyboard use at work group (P for trend = 0.032). Using > or = 1 hour/day to designate high keyboard use and <1 hour/day to designate low keyboard use, the prevalence ratio of CTS in the groups with high to low keyboard use was 0.55 (95% confidence interval 0.32, 0.96).

CONCLUSION

Intensive keyboard use appears to be associated with a lower risk of CTS.

Adjacent segment hypermobility after lumbar spine fusion: no association with progressive degeneration of the segment 5 years after surgery

BACKGROUND AND PURPOSE

Increased intradiscal pressure and relative segmental hypermobility are in vitro observations supporting the idea of increased postoperative load being a reason for progressive degeneration of the free mobile segment adjacent to a lumbar fusion. These mechanisms have been difficult to confirm in clinical studies, and an alternative theory claims instead that the adjacent segment degeneration follows a natural degenerative course in patients who are predisposed. We examined 9 patients 5 years after lumbar fusion, to assess whether relative hypermobility of the segment adjacent to fusion could be correlated to progressive degeneration of the same segment.

PATIENTS AND METHODS

The 9 patients, all of whom had been treated with a lumbar fusion after a preoperative intervertebral mobility assessment by spinal RSA, were re-examined 5 years after surgery. The intervertebral translations of the vertebra proximal to the fusion were determined by RSA and compared to the mobility of the same lumbar segment before fusion. The disc height and any progressive reduction at the two levels proximal to the one fused were measured on conventional radiographs.

RESULTS

Adjacent segment mobility 5 years after fusion--expressed as mean transverse, vertical, and sagittal translation of the vertebra proximal to fusion--was not significantly changed compared to the mobility measured before surgery. Increased mobility of the segment seen in 5 individual patients was not associated with progressive degeneration of the same segment or to a poor clinical outcome.

INTERPRETATION

Hypermobility of the segment adjacent to fusion is not a general finding. Increased mobility that can be seen in certain individuals does not impair the 5-year result. The significance of mechanical alterations in adjacent segment degeneration is uncertain, and it is possibly overestimated.

Radiostereometric analysis for monitoring percutaneous physiodesis. A preliminary study

Percutaneous physiodesis is an established technique for treating mild leg-length discrepancy and problems of expected extreme height. Angular deformities resulting from incomplete physeal arrest have been reported, and little is known about the time interval from percutaneous physiodesis to actual physeal arrest. This procedure was carried out in ten children, six with leg-length discrepancy and four with expected extreme height. Radiostereometric analysis was used to determine the three-dimensional dynamics of growth retardation. Errors of measurement of translation were less than 0.05 mm and of rotation less than 0.06 degrees. Physeal arrest was obtained in all but one child within 12 weeks after physiodesis and no clinically-relevant angular deformities occurred. This is a suitable method for following up patients after percutaneous physiodesis. Incomplete physeal arrest can be detected at an early stage and the procedure repeated before corrective osteotomy is required.

Five-year follow-up of socket movements and loosening after revision with impacted morselized allograft bone and cement: a radiostereometric and radiographic analysis

In 1999, we reported on the 2-year results of a series of 21 first-time socket revisions using impacted morselized allograft bone. Seven still migrated between 1.5 and 2 years. Seventeen remained for the current 5-year follow-up. No socket had been rerevised. Five sockets showed signs of radiographic loosening. These 5 cases also exhibited radiographic signs of allograft resorption as well as high rates of socket migration and rotation as measured by radiostereometric analysis. Of the 6 remaining sockets that had migrated between 1.5 and 2 years, 3 stabilized and 3 were among those with signs of radiographic loosening. Fifteen patients (15 hips) revealed pain reduction at the 5-year follow-up. Three had slight pain on walking that disappeared immediately at rest (pain score 4). All the others revealed either no pain (pain score 6) or slight pain that disappeared with activity (pain score 5). No pattern of early socket migration according to radiostereometric analysis could be identified, predicting later socket migration or loosening. The rate of cases with signs of radiographic loosening (29%, 5/17) was comparable to that reported by the Nijmegen group but the follow-up was shorter in the current study. The rate of cases with signs of radiographic loosening was comparable to both conventionally cemented socket revisions and cementless revisions. The future will show if further sockets loosen and if the loose sockets up to date will end up in rerevisions.

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

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

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 degrees, while at 5 years it was 1.6 degrees. 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.

Chronic upper extremity pain and co-occurring symptoms in a general population

OBJECTIVE

To estimate the prevalence of self reported chronic upper extremity pain associated with physical impairment in a general population, and its co-occurrence with chronic upper extremity numbness or tingling and chronic pain at other locations.

METHODS

A general health questionnaire was mailed to 3,000 persons (age 25-74 years) who were randomly selected from a general population register.

RESULTS

The response rate was 83%. The prevalence of chronic upper extremity pain associated with physical impairment was 20.8% (95% confidence interval [95% CI] 19.2-22.5), and that of co-occurring numbness or tingling was 6.7% (95% CI 5.7-7.7). Among the responders with chronic upper extremity pain associated with physical impairment, 84% reported more than 1 painful area.

CONCLUSION

Chronic upper extremity pain associated with physical impairment and co-occurring chronic upper extremity numbness or tingling were common in the general population. The presence of more than 1 location for pain in the upper extremity as well as in other parts of the body was frequent.

Severe carpal tunnel syndrome potentially needing surgical treatment in a general population

PURPOSE

To estimate the prevalence of severe carpal tunnel syndrome (CTS) that potentially needs surgical treatment in a general population.

METHODS

A health-status questionnaire was mailed to a random general population sample of 3,000 subjects (ages, 25-74 y). The responders who reported numbness and/or tingling in the median nerve distribution in the hands were asked to attend a clinical evaluation at which they completed the validated CTS questionnaire and underwent physical examination and nerve conduction tests. The CTS questionnaire measures the severity of symptoms and disability on a scale from 1 (none) to 5 (most severe). The potential need for surgery was defined as CTS symptom severity score of 3.2 or greater or functional status score of 2.5 or greater (corresponding to median preoperative scores for surgical patients in previous reports).

RESULTS

The response rate for the survey was 83%. Of the responders who reported numbness and/or tingling in the median nerve distribution in the hands 81% attended the clinical evaluation. Of the 94 subjects diagnosed with clinically certain CTS, 19 (20%; 12 with electrophysiologically proven median neuropathy) had previously undiagnosed CTS that potentially needed surgical treatment, yielding a population prevalence of 7 per 1,000 (95% confidence interval, 4-11 per 1,000).

CONCLUSIONS

In a general population there was a 0.7% prevalence of undiagnosed CTS with a severity similar to that of patients undergoing surgery. The degree to which variable numbers of this group are drawn into a medical system could account for variations in the rate of surgery performed.

Hip revision with impacted morselized allografts: unrestricted weight-bearing and restricted weight-bearing have similar effect on migration. A radiostereometry analysis

BACKGROUND

No consensus exists as to whether to let patients bear weight or not after revision of a loosened hip prosthesis using morselized and impacted allograft bone and cement. In the original description of the method, the patients were advised not to bear weight for 3 months postoperatively. Theoretically, bone graft remodeling is enhanced by mechanical load, but an increased migration of the prosthesis within the graft can also be anticipated. In addition, practicing restricted weight-bearing is cumbersome for the patients.

METHODS

The present study was initiated to evaluate the migration, as measured by radiostereometry analysis (RSA), in patients mobilized with unrestricted weight-bearing after a hip revision using the X-change Revision Instruments System. This group was compared with a previous series with restricted weight-bearing for the initial 3 months postoperatively. Seven stems and 12 sockets were evaluated by RSA over 2 years. Only patients without intraoperative complications were mobilized with unrestricted weight-bearing.

RESULTS

All 7 stems migrated in the distal direction (median 2.6 mm; range 0.8-16.5 mm) and in the posterior direction (median 2.3 mm; range 0.7-22.1 mm). Eleven of the 12 sockets migrated in the proximal direction (median 2.5 mm; range 0.2-8.1 mm). The migration rate decreased gradually in all directions, but 3 stems and 5 sockets still migrated between the 1.5- and 2-year follow-ups. There were no significant differences in migration in any direction for either the stems or the sockets compared to the group with restricted weight-bearing.

CONCLUSION

No increased migration occurred in the group free to bear weight as compared to restricted weight-bearing. We shall continue to allow unrestricted weight-bearing in cases where the femoral bone feels competent to withstand the initial load. It simplifies the postoperative mobilization, and we speculate that it might increase the remodeling of the graft.

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.

Temporary external pedicular fixation versus definitive bony fusion: a prospective comparative study on pain relief and function

Temporary external pedicular fixation is used as a prognostic instrument when treating degenerative conditions with spinal fusion. We studied the validity of the method and whether a functional test could improve the prognostic value of such fixation. Twenty-six patients with long-standing lumbar pain had an external temporary fixation. Pain levels were registered before fixation on a visual analogue scale at rest, as a mean for the previous week, and at seven different standardized activities. Walking capacity and walking speed for a standardized distance were also measured. Identical evaluations were then repeated during the external fixation and 1 year after definitive fusion. Based on the outcome of the temporary fixation, 20 patients were recommended for definitive surgical fusion. In six cases, the option of fusion surgery was rejected due to an unfavourable pain response or insufficient pain relief during the test fixation period, and this group was not further followed within the study. One year after surgery, 14 of 20 patients reported a good outcome. Solid bony fusion assessed by conventional radiography was seen in 19 patients. One patient with a poor clinical outcome had a pseudarthrosis. The mean values for pain level at rest, during last week and at the seven different activities in the functional test tended to decrease after fusion compared to the situation with temporary external fixation. In no activity did the external fixator overestimate the mean positive pain-relieving effect after definitive fusion. The walking capacity significantly increased, while the walking speed did not alter at the three different measurements. We conclude that with a good outcome ratio of 14 patients out of 19 having a solid fusion, the external frame improved patient selection and can be used as a valid prognostic instrument. The pain relief and function after definitive fusion can not be quantified by the external fixation, probably due to the fact that the stabilisation with an external frame is partial. The value of the functional test design presented is moderate, and an outcome evaluation comprising pain relief at rest and mean pain level during a week in fixation seems adequate.

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 degrees to 2.0 degrees. 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.

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.

Results of hip revision using the Exeter stem, impacted allograft bone, and cement

The Exeter stem and impacted, morselized allograft bone and cement were used in the revisions of 18 consecutive femoral components (17 patients). The primary arthroplasty had been done because of osteoarthritis. All of the femoral components were revised for the first time because of aseptic loosening. The migration pattern of the Exeter stem after revision was studied using roentgen stereophotogrammetric analysis. At 2 years after surgery, all 18 femoral stems had migrated in the distal direction (average, 2.5 mm). In addition, seven of the stems had migrated in the medial direction (average, 1.3 mm), and two stems had migrated in the lateral direction (0.5 mm and 1 mm, respectively). Sixteen of the femoral stems also had migrated in the posterior direction (average, 2.9 mm), but none migrated in the anterior direction. The migration rate decreased gradually with time during the followup. Six femoral stems continued to migrate between 1.5 and 2 years after surgery. In patients with major femoral bone deficiency at the time of hip revision, the use of impacted morselized allograft bone and cement yielded an initial fixation similar to that obtained in conventionally cemented revisions. Pain had improved in all patients at the 2-year followup.

Carpal tunnel syndrome with severe sensory deficit: endoscopic release in 18 cases

Carpal tunnel syndrome (CTS) with severe sensory deficit was treated with endoscopic carpal tunnel release in 18 hands of 16 consecutive patients (median age 72 (28-92) years). In all hands, preoperative 2-point discrimination (2-PD) exceeded 15 mm in the radial and ulnar sides of the pulps of at least 2 of the 3 radial digits. All patients underwent an independent evaluation and answered a questionnaire concerning 11 activities of daily living (ADL) preoperatively and 6 months postoperatively. Complete resolution or improvement in daytime numbness and tingling was reported in 12 of 17 hands, of night symptoms in 12 of 16 hands, and of pain in 10 of 11 hands. The median ADL score improved from 3.1 to 1.4 (on a 1- to 5-point scale). 13 of the 16 patients were satisfied with the outcome. Two-PD had normalized in 14 hands and improved in 2. The results indicate that endoscopic carpal tunnel release is effective in improving symptoms and function in patients with CTS and severe sensory deficit, and that the prognosis for sensory recovery is good.

Radiostereometric analysis in hip revision surgery--optimal time for index examination: 6 patients revised with impacted allografts and cement followed weekly for 6 weeks

We revised the hip (6 stems and 5 sockets) with impacted morselized allografts and cement in 6 patients. We followed prosthetic migration by roentgen radiostereometric analysis (RSA) every 7th day for 6 weeks after the first (index) examination performed on the first postoperative day before mobilization. Most of the migration occurred during the first 2 weeks. In most cases more than half of the distal stem migration was seen between the 1st and 14th days. In all cases, the stem and socket migrations slowed down gradually and several prosthetic components had become stable after 5 weeks. We conclude that it is essential to perform the index RSA examination on the 1st or 2nd day after surgery and to state when and how weight bearing should be permitted. Otherwise it will be difficult to compare prosthetic migration in various studies and define normative values for migration predicting survival.

Is there increased intervertebral mobility in isthmic adult spondylolisthesis? A matched comparative study using roentgen stereophotogrammetry

STUDY DESIGN

By roentgen stereophotogrammetric technique, the intervertebral mobility of the spondylolytic segment in eight patients was measured and compared with the mobility of eight nonspondylolytic patients matched according to sex, afflicted segment, and grade of disc degeneration.

OBJECTIVES

To compare the intervertebral mobility of a spondylolytic segment with the mobility of a segment without spondylolysis in adult patients with back pain.

SUMMARY OF BACKGROUND DATA

Evidenced by the resulting olisthetic deformity and supported by the outcome from prior investigations, spondylolysis is assumed to induce spinal segmental instability/hypermobility.

METHODS

After percutaneous application of tantalum indicators for roentgen stereophotogrammetric technique, the intervertebral translations of the spondylolytic fifth lumbar vertebra were measured in eight adult patients with low back pain and low-grade olisthesis. Eight other patients without spondylolysis but with low back pain presumably on degenerative basis were chosen for comparison and had an identical measuring procedure using roentgen stereophotogrammetric technique. The two groups were matched in pairs according to sex, afflicted segment, and grade of disc degeneration.

RESULTS

No significant difference was registered considering the intervertebral mobility for matched pairs in the two groups neither along the sagittal nor the vertical axis. The transverse translations were mostly negligible in both groups.

CONCLUSION

The spondylolytic defect in pars interarticularis does not cause permanent instability/hypermobility detectable in the adult patient with low back pain and low-grade olisthesis.

A method to evaluate the in vivo behaviour of lumbar spine implants

The aim of the study was to design a method for evaluating the stabilizing effect of different lumbar spine implants in vivo, and to apply this method to a comparison of plates versus rods in lumbar spine posterolateral fusion using transpedicular screw fixation. Fourteen patients, seven operated on with transpedicular plates and screws (VSP), and seven operated on with rods and screws (Diapason), matched according to number of levels fused, had tantalum markers inserted in the vertebrae at surgery, enabling roentgen stereophotogrammetric analysis (RSA). Mean patient age was 45 (range 33-56) years. In each group, two patients underwent fusion between L4 and L5, three between L5 and S1, and two from L4 to S1. In three patients, concomitant nerve root decompression was performed using a facet joint preserving technique. RSA was performed 4 weeks after surgery. This interval was chosen to allow enough time for soft tissue healing, but not fusion healing, to occur. RSA was performed in supine and standing position without any mobility provocation, in line with the postoperative regimen given. Movements between the outermost vertebrae of the fusion were calculated along the transverse, vertical and sagittal axes. The method of measurement along these three axes has previously been determined to be accurate to 0.3, 0.6 and 0.7 mm, respectively. One patient stabilized with rods and screws between L5 and S1 displayed a sagittal translation of 1.01 mm but no mobility along the transverse or vertical axes. In the remaining 13 patients, positional change from supine to standing did not provoke any intervertebral mobility above the RSA accuracy along any of the axes. With the limited provocation described, in line with the postoperative regimen for lumbar fusion patients, plates with transpedicular screws and rods with transpedicular screws both seem to give adequate intervertebral stability in posterolateral lumbar fusions.

[Prevalence for clinically proved carpal tunnel syndrome is 4 percent]

This article summarizes the results of a large-scale population-based study conducted to determine the prevalence of carpal tunnel syndrome in the Swedish general population. The study utilized a health questionnaires as well as clinical and electrophysiological examinations. Population prevalence rates of carpal tunnel syndrome, based on clinical diagnosis and electrophysiological criteria, were calculated. Obesity and specific work-related hand activities were shown to be risk factors for carpal tunnel syndrome.

Median nerve latency measurement agreement between portable and conventional methods

A portable nerve conduction testing device was compared with a conventional method of measuring median nerve distal latencies. In a population-based study, a health questionnaire was mailed to a random sample of 3000 participants (aged 25 to 74 years). Two hundred and sixty-two responders with numbness and/or tingling in the median nerve distribution, and 125 asymptomatic responders underwent clinical examination as well as portable and conventional median nerve distal latency measurements. Motor latency measured with the portable device was on average 0.1 millisecond (ms) lower than motor latency measured with the conventional method (95% limits of agreement, -0.8-0.5 ms). Sensory latency (wrist-to-index finger) measured with the portable device was on average 0.3 ms lower than sensory latency (long finger-to-wrist) measured with the conventional method (95% limits of agreement, -0.7-0.1 ms). Strong correlations were found between the latencies measured by the portable and conventional methods (Pearson correlation coefficient, 0.90-0.93). The agreement between the portable and conventional methods in measuring median nerve distal latencies appears to be acceptable. The cut-off value for abnormal sensory latency needs to be lower for the portable than the conventional method if the present measurement techniques are used.

Incomplete incorporation of morselized and impacted autologous bone graft: a histological study in 4 intracorporally grafted lumbar fractures

Morselized and impacted bone allografts are used successfully in hip and knee revisions, but experiments using bone chambers indicate that impaction actually can delay ingrowth of new bone into a graft. To understand the remodeling and incorporation process of morselized and impacted grafts, we studied the incorporation of morselized impacted autografts in lumbar fractures histologically. 4 patients were operated on for Th XII-LI fractures. The fractures were stabilized by VSP plates and transpedicular screws in the vertebrae above and below the fractured one. Autologous bone graft was packed into the fractured vertebral body through one of the pedicles. After 18-20 months, the plates were removed and biopsies were obtained from various locations in the fractured vertebra. All fractures were at this time clinically and radiographically healed. Histologically, in all cases, large areas of the autograft in the vertebral body were unvascularized and partially or entirely necrotic. As with morselized bone in hip revisions, evaluation of graft incorporation requires histological examination. Full osseous incorporation of a graft is not always necessary for a good clinical result.

Patient satisfaction, function and return to work after knee arthroplasty

We investigated the working status during 2 years before and 2 years after primary knee prosthetic operation for arthrosis in order to identify preoperative factors predicting patient satisfaction, function and working capacity. 162 patients (86 women) younger than 60 years of age when operated on with a knee prosthesis during 1993 were studied. 91% of the patients returned a Nottingham Health Profile (NHP) questionnaire, and the Social Insurance Office could supply data on all patients. There was a positive association between the duration of pre- and postoperative sick-leave in the patients who returned to work. Preoperative sick-leave longer than 180 days increased the risk of postoperative disability pension, which was not found to be influenced by the grade of the work. Among the 52 patients who returned to work postoperatively, all 6 NHP functional categories were better in the patients with less than 180 days of preoperative sick-leave than in the patients with more than 180 days of preoperative sick-leave. The overall patient satisfaction was greater among patients who went back to work postoperatively. We conclude that long sick-leave before a knee prosthetic operation increases the risk of long postoperative sick-leave and disability pension and impairs the quality of life.

Migration of the acetabular component after revision with impacted morselized allografts: a radiostereometric 2-year follow-up analysis of 21 cases

In a consecutive series of hip revisions due to mechanical loosening, using impacted morselized allografts and cement, we followed 21 acetabular components by radiostereometric analysis (RSA) during 2 years. All but 1 acetabular component migrated in the proximal direction (median 2.1 (0.5-6.4) mm). 6 components migrated in the medial direction (median 0.8 (0.4-1.2) mm) and 6 in the lateral (median 0.8 (0.4-2.0) mm). 14 components migrated in the posterior direction (median 0.8 (0.3-2.3) mm) and 1 in the anterior 0.6 mm. The migration rate gradually decreased in all directions, but 7 acetabular components still migrated in at least 1 direction (median 0.3-0.6 mm) between 1.5 and 2 years postoperatively.

Prevalence of carpal tunnel syndrome in a general population

CONTEXT

Carpal tunnel syndrome (CTS) is a cause of pain, numbness, and tingling in the hands and is an important cause of work disability. Although high prevalence rates of CTS in certain occupations have been reported, little is known about its prevalence in the general population.

OBJECTIVE

To estimate the prevalence of CTS in a general population.

DESIGN

General health mail survey sent in February 1997, inquiring about symptoms of pain, numbness, and tingling in any part of the body, followed 2 months later by clinical examination and nerve conduction testing of responders reporting symptoms in the median nerve distribution in the hands, as well as of a sample of those not reporting these symptoms (controls).

SETTING

A region in southern Sweden with a population of 170000.

PARTICIPANTS

A sex- and age-stratified sample of 3000 subjects (age range, 25-74 years) was randomly selected from the general population register and sent the survey, with a response rate of 83% (n = 2466; 46% men). Of the symptomatic responders, 81% underwent clinical examination.

MAIN OUTCOME MEASURES

Population prevalence rates, calculated as the number of symptomatic responders diagnosed on examination as having clinically certain CTS and/or electrophysiological median neuropathy divided by the total number of responders.

RESULTS

Of the 2466 responders, 354 reported pain, numbness, and/or tingling in the median nerve distribution in the hands (prevalence, 14.4%; 95% confidence interval [CI], 13.0%-15.8%). On clinical examination, 94 symptomatic subjects were diagnosed as having clinically certain CTS (prevalence, 3.8%; 95% CI, 3.1%-4.6%). Nerve conduction testing showed median neuropathy at the carpal tunnel in 120 symptomatic subjects (prevalence, 4.9%; 95% CI, 4.1%-5.8%). Sixty-six symptomatic subjects had clinically and electrophysiologically confirmed CTS (prevalence, 2.7%; 95% CI, 2.1%-3.4%). Of 125 control subjects clinically examined, electrophysiological median neuropathy was found in 23 (18.4%; 95% CI, 12.0%-26.3%).

CONCLUSION

Symptoms of pain, numbness, and tingling in the hands are common in the general population. Based on our data, 1 in 5 symptomatic subjects would be expected to have CTS based on clinical examination and electrophysiologic testing.

The influence of parental age on the risk of Wilms' tumour

The Brazilian Wilms' Tumour Study Group carried out a hospital-based multicentre case-control study of potential risk factors for the disease between April 1987 and January 1989. The parents of 109 cases of Wilms' tumour (WT) were interviewed when they were admitted to hospital for diagnosis and treatment. Also interviewed were the parents of two controls per case, matched for age, sex and interviewer, who were admitted to the same or nearby hospitals for treatment of non-neoplastic conditions. Odds ratios adjusted for family income and parental education were calculated by conditional logistic regression. Among cases diagnosed before 25 months of age there was a marked gradient of increasing risk of WT with increasing maternal age at the time of the child's birth. There was no increased risk for cases diagnosed after 25 months of age. The effects of paternal age were less marked. Possible explanations for these results are discussed.

External pedicular fixation of the lumbar spine: outcome evaluation by functional tests

We analyzed the pain-relieving effect and the functional outcome during external pedicular fixation of the lumbar spine. Twenty patients were included, and the diagnoses were disc degeneration with or without facet joint arthrosis in eight patients, pain after decompression in six patients, spondylolysis/olisthesis in two patients, other types of lumbar anomalies in three patients, and pseudarthrosis after prior uninstrumented fusion in one patient. Before application of the external frame, the pain level on the Visual Analogue Scale was registered at rest, as a mean level for the preceding week, and at seven different functional tests. Maximum walking capacity and walking time needed for a standardized distance were also measured. The same test procedure was repeated 1 week postoperatively with the external frame applied in locked position. With stabilization, 11 patients reported pain relief at rest and 14 when approximating the mean pain level for the week. Both these measured levels correlated to the pain level at all of the seven functional tests. Thus, the patients selected for a subsequent fusion based on pain relief during extended functional provocation would not differ from the patients selected by using only the pain-relieving effect at rest. The patients reporting pain relief tended to increase their walking distance (p = 0.06, t test) but not the speed of walking.

Stability of lumbar fusion with transpedicular fixation determined by roentgen stereophotogrammetric analysis

STUDY DESIGN

An evaluation of the intervertebral stability of transpedicular instrumentation in posterolateral lumbar fusions by roentgen stereophotogrammetric analysis.

OBJECTIVES

To determine the in vivo intervertebral stability of posterolateral lumbar fusions augmented with transpedicular screws and plates.

SUMMARY OF BACKGROUND DATA

Transpedicular bone screw systems have been found to be as safe and clinically effective as other types of devices in stabilizing surgery of the spine. Many experimental studies have yielded basic data on the stabilizing implant effect in vitro, but the exact in vivo stabilizing effect on human lumbar vertebrae has not been presented previously.

METHODS

In 12 patients, the intervertebral stability of posterolateral fusion in the lower lumbar spine augmented with transpedicular screws and plates was evaluated by serial roentgen stereophotogrammetric analysis with the patients in supine and erect positions 1 year after surgery.

RESULTS

Screws in each fused vertebra yielded stable fixation or permitted sagittal intervertebral translations smaller than 1 mm induced by the positional change. A widely decompressed and destabilized vertebra without screw fixation yielded persisting intervertebral translations.

CONCLUSIONS

The current study demonstrated the adequacy of in vivo stability of lumbar fusions augmented with transpedicular screws and plates. Sagittal translation seems easier to elicit than movements along the other three-dimensional axes. A widely decompressed and destabilized vertebra without screw fixation increases the risk for persisting intervertebral translations. The roentgen stereophotogrammetric analysis technique described seems to be a good way of comparing the in vivo behavior of different implant systems.

Symptoms, disability, and quality of life in patients with carpal tunnel syndrome

We used validated outcome instruments to measure symptoms, disability, and health-related quality of life in 58 patients with carpal tunnel syndrome (CTS). The patients completed the CTS instrument before and 6 weeks, 3 months, and 6 months after surgery and the Short Form-36 (SF-36) before and 3 months after surgery. The size of clinical change detected by each outcome measure was estimated by the standardized response mean (mean change/ standard deviation of the change). Large improvement was observed for the CTS symptom scale (mean standardized response, 1.4-1.9) and function scale (0.8-1.1). Improvement in SF-36 scales was large for pain (1.0) and moderate for physical role, mental health, and the physical component summary (0.5-0.6). Compared with the general population SF-36 norms (n = 2,181), CTS patients had significantly worse scores for physical functioning, physical role, pain, vitality, and the physical component summary before surgery. After surgery, SF-36 scores had normalized except for physical role and the physical component summary.

Assessment of sagittal plane segmental motion in the lumbar spine. A comparison between distortion-compensated and stereophotogrammetric roentgen analysis

STUDY DESIGN

Sagittal plane translatory and rotatory motion was measured in 15 lumbar motion segments of 8 patients by distortion-compensated and stereophotogrammetric Roentgen analysis.

OBJECTIVE

To compare measurement precision of the new distortion-compensated Roentgen analysis protocol with that of the established Roentgen stereophotogrammetric technique under realistic clinical conditions.

SUMMARY OF BACKGROUND DATA

Roentgen stereophotogrammetric analysis constitutes the most precise method available to assess segmental motion. Because of the invasive nature of the procedure, however, there is interest in alternative, noninvasive protocols suitable for studying larger patient cohorts.

METHODS

In 8 patients, segmental motion of 15 lumbar segments that had undergone previous spinal surgery was assessed from stereo views by using Roentgen stereophotogrammetric analysis. Sagittal plane segmental motion was assessed by distortion-compensated Roentgen analysis. Sagittal plane translatory and rotatory motion data obtained by both methods were compared.

RESULTS

With respect to Roentgen stereophotogrammetric analysis, sagittal plane rotation was determined by distortion-compensated Roentgen analysis with an error (standard deviation) of 1.4 degrees and a mean difference of less than 0.05 degree. Sagittal plane translation was determined by distortion-compensated Roentgen analysis, with an error of 1.25 mm and a mean difference 0.5 mm.

CONCLUSION

Measurement precision of distortion-compensated Roentgen analysis is slightly inferior to that of Roentgen stereophotogrammetric analysis but substantially higher than that of conventional protocols assessing lumbar segmental motion. If measurement precision is considered adequate and if a noninvasive technique is indicated, distortion-compensated Roentgen analysis can be used to provide reliable motion data required for epidemiologic and clinical studies.

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.

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.

Contained and noncontained lumbar disc herniation in the same patient. Two case reports

STUDY DESIGN

A case report containing description of symptoms, signs, and selected treatment in two patients with lumbar disc herniation where the type of herniation changed from contained to noncontained in less than 1 year.

OBJECTIVES

To demonstrate the difference in clinical appearance related to the type of herniation.

SUMMARY OF BACKGROUND DATA

The clinical appearance of lumbar disc herniation regarding onsets of symptoms, severity of pain, and clinical findings are related to the type of herniation, as is the treatment.

METHODS

Two cases reports are presented with description of anamneses, clinical findings, neuroradiographic findings, and treatment.

RESULTS

Both patients suffered from a transient left-side sciatica due to a contained lumbar disc herniation, improved by physiotherapy. After several months, both patients had an instantaneous increase in contralateral leg pain, and the recurrent, intense pain was caused by a sequestration of the previous contained herniation. The neurologic findings were more severe, and the patients were operated on, with subsequent improvement.

CONCLUSIONS

The case reports illustrate the difference in clinical appearance of disc herniation related to the type of herniation, with a more aggressive clinical appearance in conjunction with perforation of the posterior longitudinal ligament with extrusion of disc material.

Patient satisfaction and return to work after endoscopic carpal tunnel surgery

One hundred twenty-eight patients with idiopathic carpal tunnel syndrome were evaluated before surgery and 3 and 6 months after unilateral endoscopic carpal tunnel release. The variables analyzed included patient demographics, symptoms and signs, activities of daily living (ADL), sensibility and strength measurements, preoperative distal motor latency of the median nerve, operating surgeon, postoperative palmar pain and tenderness, return to work, and patient satisfaction with the results of surgery. Multivariate statistical analyses were performed, with patient satisfaction at 6 months after surgery and the time until return to work after surgery as the dependent variables. On stepwise logistic regression analysis of all preoperative variables, significant predictors of patient dissatisfaction at 6 months after surgery were higher age, heavy vibration exposure, worse ADL score, and better distal motor latency. Analysis of all preoperative and 3-month postoperative variables showed heavy vibration exposure, better distal motor latency, and worse 3-month postoperative ADL score to have the strongest independent correlation with patient dissatisfaction at 6 months. No significant independent association was found between any of the preoperative variables studied and the length of time until return to work after surgery.

Use of outcome instruments to compare workers' compensation and non-workers' compensation carpal tunnel syndrome

Validated outcome instruments were used to compare treatment outcomes of carpal tunnel syndrome (CTS) in workers' compensation and non-workers' compensation patients. A self-administered questionnaire consisting of the generic Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the disease-specific Carpal Tunnel Syndrome Instrument was mailed to 277 patients randomly selected from all 1050 new patients treated for CTS during a 1-year period. A total of 212 patients (61 workers' compensation and 151 non-workers' compensation) responded to the survey 7-22 (mean, 14) months after the initiation of treatment, yielding a response rate of 76%. Workers' compensation patients had worse mean scores than non-workers' compensation patients in 6 of the 8 SF-36 scales and in the 2 Carpal Tunnel Syndrome Instrument scales, but validating multivariate analysis could not verify significant score differences in any of the scales. Thus, this study could not demonstrate inferior treatment outcomes of CTS in workers' compensation patients as measured by standardized generic and disease-specific outcome instruments.

Posterolateral lumbar fusion using facet joint fixation with biodegradable rods: a pilot study

Roentgen stereophotogrammetric analysis (RSA) was used to assess whether there is a potential for biodegradable rods crossing the denuded facet joints to increase the stability and healing rate of lumbar posterolateral fusions. Eleven consecutive patients with lumbosacral disc/facet joint degeneration had a posterolateral fusion augmented with 2- or 3.2-mm biodegradable rods passing perpendicularly through the center of the denuded facet joints. The patients were followed-up with RSA in supine and erect positions monthly from the 2nd to the 6th postoperative month, and again 1 year postoperatively. All seven L5-S1 fusions healed. Four cases were stable as defined by RSA within 3 months, two within 6 months, and one within 1 year. One L4-S1 fusion could not be evaluated by RSA. None of the remaining three L4-S1 fusions fully healed. In all three cases 1- to 3-mm intervertebral translations remained at 1 year. None of the 11 fusions showed any radiographic signs of osteolysis around the biodegradable rods. The promising results of this pilot study indicate that posterolateral L5-S1 fusion augmented with transarticular biodegradable rods crossing the denuded facet joints may yield rapid intervertebral stabilization and a high healing rate without any adverse rod effects. This may be due to enhanced initial fusion stabilization and/or increased ossification induced by the rods.

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 spondylolysisolisthesis 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.

Endoscopic carpal tunnel release: prospective assessment of 255 consecutive cases

A prospective study was conducted to evaluate the efficacy and safety of two-portal endoscopic carpal tunnel release. Two hundred and fifty-five consecutive hands (204 patients) were operated on by one surgeon using general or regional anaesthesia in the first 48 hands and local anaesthesia in the following 207 hands. The patients were evaluated preoperatively and 3 and 6 months postoperatively by an independent examiner. At the 6-month follow-up, 83% reported complete relief of symptoms and 89% were satisfied with the results of surgery. The median time until return to work was 17 days. Complications included five postoperative digital neurapraxias, all occurring under general or regional anaesthesia, and four open reoperations due to persistent symptoms. Two-portal endoscopic carpal tunnel release can be effective and safe and appears to shorten the time until return to work. The use of local anaesthesia might be important in avoiding neurological complications.

Impaired quality of life 10 to 20 years after primary hip arthroplasty

The functional results in terms of quality of life 10 to 20 years after cemented total hip arthroplasty due to primary arthrosis were evaluated in 187 patients with nonrevised hips by use of the Nottingham Health Profile questionnaire. Function was impaired compared with age- and sex-matched random control subjects.

Anterior acromioplasty. A comparison of two techniques

A prospective randomised study was made of 20 patients who underwent acromioplasty for the chronic impingement syndrome. Ten were operated on by Neer's technique and 10 with a modification where the deltoid origin was spared. Rehabilitation was more rapid with a better range of movement in the latter group. Acromioplasty with this modification offers benefits compared with the standard procedure.

Evaluation of portable nerve conduction testing in the diagnosis of carpal tunnel syndrome

A portable nerve conduction testing instrument (the electroneurometer) was investigated to evaluate its sensitivity and specificity in the diagnosis of carpal tunnel syndrome. The preoperative electroneurometer measurements of distal motor and sensory latencies of the median nerve in 43 consecutive hands with a clear diagnosis of carpal tunnel syndrome (typical history, clinical signs, and complete symptom relief after surgery) were analyzed. Distal motor and sensory latencies of the median nerve were also measured in 60 hands of asymptomatic healthy volunteers. The sensitivity of the device in the hands with carpal tunnel syndrome was 58% for distal motor latency (upper limit of normal, 4.4 ms) and 65% for distal sensory latency (upper limit of normal, 3.5 ms). The specificity of the instrument in the control hands was 87% and 92% for distal motor and sensory latency, respectively. Receiver operating characteristic curves showed distal sensory latency measurement to be a superior diagnostic test, with 3.3 ms as optimal upper limit of normal, giving a sensitivity of 74% and a specificity of 87%. The sensitivity and specificity of the device are comparable to those reported for conventional nerve conduction studies.

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.

Orthosis as prognostic instrument in lumbar fusion: no predictive value in 50 cases followed prospectively

To evaluate pain relief in a lumbar orthosis as a predictor for good clinical results after solid fusion, all patients scheduled for such a surgical procedure were preoperatively encouraged to use an orthosis, soft or rigid, for 3 weeks. Grade of back pain relief as a percent using the orthosis was assessed by the patients and was registered before surgery. After surgery, at 1-year follow-up, patients with nonunion demonstrated radiographically were excluded from the series. Thus, 50 patients with solid fusion could be identified and followed for at least 2 years prospectively. At follow-up these 50 patients graded the pain relief induced by the fusion. In the preoperative corset test, 31 patients experienced significant back pain relief, meaning a reduction of at least 50%. No applicable correlation was found, however, between outcome in this corset test and the eventual clinical result expressed as improvement/no improvement after solid fusion. The two types of orthoses did not differ in this aspect. We conclude that the orthosis, rigid or soft, is not a useful instrument when selecting patients for lumbar fusion.

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.

Heat generation and heat protection in methylmethacrylate cementation of vertebral bodies. A cadaver study evaluating different clinical possibilities of dural protection from heat during cement curing

For metastatic disease of the spine, anterior operations on the vertebral bodies often include methylmethacrylate cementation. The cement curing process may produce high temperatures in the surroundings, as demonstrated in joint replacement surgery, and there is a risk of thermal injury to the spinal nerves. In cadavers, we studied the heat arising during curing of cement on the dural sac, and the temperature of the cement surface was measured when the vertebral body was reconstructed using acrylic cement in the same way as in tumor surgery. The temperature increase on the surface of the dural sac during polymerization was between 4 degrees and 12 degrees C, depending on the amount of protection. Only a moderate temperature elevation was measured on the surface of the dural sac, provided that the posterior cortex of the vertebra was retained together with 0.5 cm of the spongious bone or a silicone membrane.

Bony atrophy after mega total hip replacement for bone tumors. 11 cases followed for 3-15 years

We followed 11 patients 3-15 years after a cemented mega total hip replacement for a proximal femoral bone tumor. 7/8 survivors had good function and only occasional pain. 1 hip had been revised because of deep infection and in 1 case the cup had been exchanged because of aseptic loosening. 2 patients had been operated on because of local recurrence of the tumor. At follow-up, 1 patient had radiographic signs of loosening of the stem after 7 years. There was in 8 cases a pronounced athropy of the femoral cortical bone, not correlated to loosening of the stem.