1997 Volvo Award winner in clinical studies. The effect of pedicle screw instrumentation on functional outcome and fusion rates in posterolateral lumbar spinal fusion: a prospective, randomized clinical study.

STUDY DESIGN: A prospective randomized clinical study. OBJECTIVES: To evaluate supplementary pedicle screw fixation (Cotrel-Dubousset) in posterolateral lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: The rationale behind lumbar fusion is to eliminate pathologic motion to relieve pain. To improve fusion rates and to allow reduction, a rigid transpedicular screw fixation may be beneficial, but the positive effect of this may be counter-balanced by an increase in complications. METHODS: The inclusion criteria were severe, chronic low back pain from spondylolisthesis Grades 1 and 2 or from primary or secondary degenerative segmental instability. One hundred thirty patients were randomly allocated to receive no instrumentation (n = 66) or Cotrel-Dubousset instrumentation (n = 64) in posterolateral lumbar fusion. Variables were registered at the time of surgery and at 1 and 2 years after surgery. RESULTS: Follow-up was achieved in 97.7% of the patients. Fusion rates deduced from plain radiographs were not significantly different between instrumented and noninstrumented groups. The functional outcome assessed by the Dallas Pain Questionnaire improved significantly in both groups, and there were no significant differences in results between the two groups, except for significantly better (P < 0.06) functional outcome in relation to daily activities in the instrumented group when neural decompression had been performed. The global patients' satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group (not significant). Fixation of instrumentation increased operation time, blood loss, and early reoperation rate significantly. Patients experienced only a few minor postoperative complications; none were major. Two infections appeared in the Cotrel-Dubousset group. Significant symptoms from misplacement of pedicle screws were seen in 4.8% of the instrumented patients. CONCLUSIONS: Lumbar posterolateral fusion with pedicle screw fixation increases the operation time, blood loss, and reoperation rate, and leads to a significant risk of nerve injury. The functional outcome improves significantly with high patient satisfaction, with or without instrumentation. No significant differences were observed between the two groups in functional outcome and fusion rate. The only gain in functional outcome from instrumentation was found in the daily activity category in patients with supplementary neural decompression. The results of this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

Incomplete ruptures of the anterior cruciate ligament.

In a prospective study, 41 consecutive patients with a partial tear of the anterior cruciate ligament, diagnosed by arthroscopy, were reviewed after an average of 17 months, having been in plaster for six weeks after injury. Their average age was 29 years and review included clinical examination, measurement of anterior and posterior laxity with the Stryker knee laxity tester as well as evaluation of knee function and activity level. Twenty-one patients had unstable knees at follow-up; the mean total anteroposterior laxity for these patients was 12.6 +/- 3.9 mm compared with 7.1 +/- 4.3 mm for the normal knee. Most patients had few symptoms, but there was a significant reduction in the mean level of activity in the unstable group.

Migration of hydroxyapatite coated femoral prostheses. A Roentgen Stereophotogrammetric study.

We allocated randomly 27 patients undergoing 28 primary uncemented total hip replacements (THR) to receive prosthetic components of similar design with either plasma-sprayed titanium alloy (Ti) coating (n = 13) or hydroxyapatite (HA) coating (n = 15). After some exclusions, 15 of the patients (15 THR; 7 with HA- and 8 with Ti-coating) were followed by roentgen stereophotogrammetric analysis at 3, 6 and 12 months to measure migration of the femoral component. Twenty-six of the patients (26 THR) were followed clinically and by conventional radiography. All the femoral components had migrated at 3 months. From 3 to 12 months, the migration of Ti-coated components continued whereas the HA-coated components had stabilised. At 12 months there was significantly less migration of the HA-coated components (p < 0.05). The maximum subsidence was 0.2 mm in both groups. The Harris hip score was equal in the two groups preoperatively but at follow-up it was better in the HA-coated group (p < 0.05) and visual analogue scale scores showed that they had less pain (p < 0.05).

Treatment of unstable Colles' fractures by external fixation.

Twenty-six patients with unstable comminuted fracture of the distal part of the radius were treated with external fixation using Hoffmanns external fixation device. The average follow-up was 29 months. The anatomical results were 85% good or excellent, 10% fair and 5% poor. Functionally, 60% were good or excellent, 25% fair and 15% poor. There were three major complications and nine minor complications, the overall complication rate being 60%, though only 15% were major. The method is recommended when dealing with fractures of type VII and VIII, but not as a general routine.

[The effect of pedicle screw instrumentation on posterolateral spinal fusion. A prospective, randomized study with a two-year follow-up]. / Effekten af pedikelskrueinstrumentering ved posterolateral lumbal spondylodese. Et prospektivt randomiseret studium med to års opfølgning.

The aim was to evaluate the effect of supplementary pedicle screw fixation (Cotrel-Dubousset [CD]) in posterolateral lumbar spinal fusion. The study comprises 130 patients undergoing lumbar or lumbosacral fusion for spondyloisthesis grades I-II or degenerative segmental instability conditions. The patients were randomly allocated for no instrumentation (n = 66) or CD instrumentation (n = 64) in posterolateral lumbar fusion. A 97.7% follow-up was achieved. There were no significant differences between the two groups concerning fusion rates assessed by X-ray or functional outcomes assessed by Dallas Pain Questionnaire. The global patient satisfaction was 82% in the instrumented group versus 74% in the noninstrumented group. Instrumentation increased both operation time, blood loss, and early re-operation rates significantly. A high patient satisfaction was found in both groups. However, the results from this study do not justify the general use of pedicle screw fixation alone as an adjunct to posterolateral lumbar fusion.

Synovial venous hemangioma of the knee joint.

Hemangiomas rarely involve joints and less than 100 synovial hemangiomas have been reported. A case of a localised, intermediate type of venous angioma in the knee-joint causing severe knee pain is reported here, and the characteristic features are discussed. Arthroscopy is suggested as a valuable diagnostic procedure in finding and examining such tumors.

Arthroscopy in the diagnosis of acute injuries to the knee joint.

This study evaluates the role of arthroscopy in the diagnosis of acute injuries to the knee. One hundred and fifty four patients with a suspected ligament injury or effusion of the knee joint underwent arthroscopy. A haemarthrosis was present in 82% and a bloodless effusion in 10%. Meniscal tears were found in 19% of the knees. Fresh ligament ruptures were present in 71% and an associated haemarthrosis in 95% of these; 65% were partial tears. The commonest isolated lesion was a complete or partial tear of the anterior cruciate, which occurred in 15% of cases. More than one ligament injury occurred in 56%, the commonest combination being tears of the anterior cruciate and medial collateral ligaments. In a high percentage of cases, arthroscopy revealed unsuspected injuries of significance in management. In 39%, an open or closed procedure followed arthroscopy. There were no complications from the diagnostic arthroscopy. We conclude that arthroscopy provides a more accurate diagnosis than clinical examination alone, and is especially valuable for assessing the patient with a haemarthrosis of the knee.

Outpatient arthroscopy of the knee under local anaesthesia.

Arthroscopy of the knee was carried out under local anaesthesia in 313 outpatients, with arthroscopic surgery in 81. The procedure had to be abandoned because of apprehension in only 0.9%. With increasing experience, the number of arthroscopic meniscectomies increased from 5% to 64% of the lesions found. The method was particularly valuable in the assessment of patello-femoral pain since dynamic evaluation of patellar alignment, and the localisation of sensitive structures by palpation, was possible. The method is a safe, reliable and inexpensive alternative to the use of spinal or general anaesthesia for arthroscopy.

Suture of the torn anterior cruciate ligament. 5-year follow-up of 60 cases using an instrumental stability test.

60 patients were examined 5 (2-9) years after simple suture of acute rupture of the anterior cruciate ligament. In the follow-up the patients were examined clinically and by instrumental testing of stability (Acufex Knee Signature System). 10 knees had had a ligament reconstruction during the follow-up period, 28 knees were stable, and 22 unstable. By the Lysholm knee-score, function was rated excellent or good in both stable and unstable knees and the Tegner activity score dropped insignificantly. A positive correlation was found between the measured laxity and the clinical tests. Instrumental stability testing seems to be a reliable supplementary tool in the diagnosis of anterior cruciate ligament insufficiency. Ligament repair by simple suture was not better than reported results on conservative treatment.

Conservative treatment for acute rupture of the Achilles tendon.

Sixty-six patients with acute ruptures of the Achilles tendon were treated by immobilisation in a plaster cast for 12 weeks. Fifty-seven were followed up for a mean time of 70 months. Four re-ruptures occurred shortly after the initial treatment. Most patients had no or only slight complaints, three had moderate and one severe, problems. The activity level dropped slightly from 5.3 to 5.03 (Tegner score). The results are satisfactory with a low complication rate. The method is an alternative to operative repair, especially in patients declining operation and in those in whom operation or anaesthesia is contraindicated.

Arthroscopic suture of peripheral meniscal tears.

Twenty-nine patients underwent meniscal repair using an inside-to-out technique and instruments developed in our department. The tears were more than 1.5 cm in length, vertical, and located in the outer third of the meniscus. The torn segment was mobile, the remainder of the meniscus stable. After six months, fourteen out of sixteen patients achieved a good or excellent Lysholm knee score. We conclude that the technique is safe and reliable and allows better access than an arthrotomy. Care must be taken to avoid neurovascular injury.

Total shoulder replacement in rheumatoid arthritis: proximal migration and loosening.

A prospective study of 62 Neer mark II total shoulder arthroplasties performed during the period from 1981 to 1990 on 51 patients with rheumatoid arthritis was undertaken to evaluate factors associated with component loosening and proximal humeral migration. Thirty-two (51%) showed proximal migration of the humerus before surgery was performed. The mean follow-up time was 92 months (range 52 to 139 months). The results revealed proximal migration in 55% of the patients (34 shoulders), and 40% (25 shoulders) showed progressive radiographic loosening of the glenoid component. Five of 12 press-fit humeral components demonstrated progressive radiographic loosening, whereas no signs of loosening were found in 50 cemented humeral components. In spite of progressive component loosening and progressive migration, this study demonstrated good pain relief in 89% of the patients (55 shoulders) and also a significant improvement in range of movement and function. The presence of proximal humeral migration did not significantly influence the average results-neither pain relief, range of movement, abduction force, nor function. Also, component loosening did not significantly influence the average pain relief, range of movement, abduction force, or function. The risk of clinical asymptomatic loosening is a relatively late complication that is eventually followed by pronounced bone destruction related to the loose component. Long-term radiographic control of total shoulders with rheumatoid arthritis is recommended. Hemiarthroplasty with a cemented humeral prosthesis may be a better treatment in the end stage of rheumatoid arthritis of the shoulder.