P1621m6A RNA-methylation in the progression of heart failure

Introduction

N6-Methyladenosine (m6A) is the most abundant modification of RNA and was found to be a dynamic and reversible process. It is found in many classes of RNA, such as mRNA, noncodingRNA (ncRNA) and microRNA (miR). mRNA methylation can affect splicing, transport and storage or decay, ncRNA methylation might influence signal transduction directly as well as it might affect miR interference. Deregulation of such epigenetic processes and aberrant gene expressions are important mechanisms in heart failure. Here we studied the potential relevance of m6A RNA-methylation in cardiac hypertrophy and heart failure development.

Methods and results

m6A RNA-methylation was analysed via methylated RNA immunoprecipitation (meRIP) and subsequent next generation sequencing (NGS). Our data shows that approximately one quarter of the transcripts in the healthy mouse (24.09%) and human heart (14.6%) exhibit m6A RNA-methylation. A mild positive correlation of m6A RNA-methylation at the 5'UTR and coding region with transcript level was observed while m6A RNA-methylation at the 3'UTR showed a mild negative correlation.

We analysed heart failure in mice and humans and observed that changes in m6A RNA-methylation exceed changes in gene-expression (in human data 1219 differentially methylated and 198 diff. expressed, with 30 showing changes in both methylation and expression; in mouse data 1135 diff. methylated and 127 diff. expressed, with 47 showing changes in both methylation and expression). In mouse and human heart failure, transcripts with altered m6A RNA-methylation were mainly linked to metabolic and regulatory pathways while changes in transcript level mainly represented changes in structural plasticity. In the diseased state m6A RNA-methylation showed no correlation to transcript level. To gain further insight into m6A mediated effects on the translational level, polysome-sequencing was applied. These data provide evidence that in the diseased heart changes in m6A RNA-methylation affect RNA translation, represented by a positive correlation (r=0.37, p=2.2e-16) of log2fc changes in translation and m6A methylation.

Conclusions

Our study describes m6A RNA-methylation at the genome-wide level in the human heart. The mouse model provides evidence that changes in m6A RNA-methylation plays an important role in heart failure development by affecting regulatory pathways distinct from those genes with altered expression levels. Our data suggest that modulation of epitranscriptomic processes such as m6A-methylation might be an interesting target for therapeutic interventions.

Acknowledgement/Funding

CRC 1002

[Influence of the postoperative activity level on tibial bone tunnel enlargement and functional treatment results following anterior cruciate ligament reconstruction using a patellar tendon autograft]

AIM

This study was performed to evaluate the influence of the postoperative activity level on tibial bone tunnel enlargement following anterior cruciate ligament reconstruction using a mid-third patellar tendon autograft.

METHODS

A clinical and radiological assessment was performed on 50 patients (21 male, 29 female, mean age 32 years, range 18 to 57 years) following ACL reconstruction using a patellar tendon autograft. The average follow-up examination was performed 18 (12 to 30) months after the operation.

RESULTS

33 patients (66 %) developed a tibial bone tunnel enlargement > 1 mm. We found a positive correlation (+ 0.59) of the grade of activity and the muscle status (+ 0.56) to the tibial bone tunnel enlargement. Patients with a major tibial bone tunnel enlargement performed at a higher (p < 0.05) postoperative activity grade (5.2 versus 4.1 in the Tegner grading), rated higher in the Lysholm (88 versus 77 points) and IKDC scores (p < 0.05) and reported a better subjective functional outcome (p < 0.05). There was no significant correlation of the results of the knee stability tests and the age of the patients to the grade of tibial bone tunnel enlargement.

CONCLUSIONS

In ACL reconstruction using a patellar tendon autograft we recommend early rehabilitation as the concomitant tibial bone tunnel enlargement does not significantly influence the clinical outcome or knee stability.

[Results of hip arthroscopy in sports related groin pain]

INTRODUCTION

The study analyses the intraoperative findings and the clinical results of hip arthroscopy in sports related groin pain.

METHODS

Between june 1998 and october 2002 we performed hip arthroscopy in 30 athletes (12 female, 18 male) with a history of sports related groin pain. Their average age was 36 (20 to 68) years. All patients had a clinical follow-up- examination at an average of 20 (12 to 48) months postoperative. The result was rated using the Larson-Score.

RESULTS

We found a lesion of the acetabular labrum and performed a partial resection at 17 patients (57 %) (synovitis: n = 28 [93 %] loose bodies: n = 6 [20 %] torn ligamentum teres: n = 4 [13 %], others: n = 2 [6 %]). 11 patients (37 %) had a cartilage degeneration grade II in the Outerbridge classification (III degrees : n = 9 [30 %], I degrees : n = 4 [13 %], 0 degrees : n = 6 [20 %]). Preoperative 14 patients (47 %) complained severe groin pain (moderate: n = 14 [47 %], slight: n = 2 [6 %]) against only 3 patients (10 %) with severe groin pain at the follow-up examination (moderate: n = 11 [37 %], slight: n = 16 [53 %]). Following hip arthroscopy 28 patients (94 %) returned to full sports activity. The Larson-Score was increased significantly (p < 0.05) rating 43 (10 to 64) points preoperative to 59 (28 to 80) points at the follow-up.

DISCUSSION

We found that persistent sports related groin pain was frequently caused by an intraarticular hip disorder. Following hip arthroscopy pain could be reduced in most patients as a return to full sports activity.

[Lig. capitis femoris. Arthroscopic diagnosis and treatment of degenerative and traumatic disorders]

The LT arises from the transverse acetabular ligament and the posterior inferior portion of the acetabular fossa and attaches to the femoral head at the fovea capitis. Lesions of the LT are accompanied by dislocation or subluxation of the hip as well as acetabular fractures. However, rupture may occur simply from a twisting injury in the absence of major trauma. Atraumatic degeneration associated with osteoarthritis and dysplasia as well as after Perthes' disease and slipped epiphysis capitis can occur. The symptoms of pain, popping, locking, and catching are nonspecific for a variety of intra-articular lesions. Most of the patients complain of deep anterior groin pain, but sometimes simply pain upon activity or loss of motion are described. No examination finding would distinguish injury to the ligament. The diagnosis of rupture of the LT remains elusive to various imaging techniques. Magnetic resonance arthrography is much more sensitive than magnetic resonance imaging at detecting various lesions but has a low sensitivity for ruptures of the LT. Lesions of the LT can be diagnosed using arthroscopy and respond remarkably well to arthroscopic débridement. Long-term results and potential consequences of treatment remain to be defined.

[Effects of harvesting the central third of the patella tendon on the kinetics of the knee joint and the retropatellar pressure]

AIM

This biomechanical study was performed to evaluate the consequences of removing the central part of the patellar tendon on the kinematics and kinetics of the femoro-patellar joint. The tendonectomy was performed in the same manner as is frequently done during anterior cruciate ligament reconstructions. Of particular interest in this study was to identify potential factors of the patellar tendon resection which could result in anterior knee pain.

METHOD

A simulated isokinetic knee extension from 120 degrees of flexion to full extension was performed on nine human knee cadaver specimens. Joint kinematics was evaluated with ultrasound sensors, and retropatellar contact pressure was measured using a thin-film resistive ink pressure measuring system. Data were taken before and after resection of the central third of the patellar tendon.

RESULTS

Harvesting of the central third of the patellar tendon resulted in an elongation of the remaining patellar tendon by less then 0.5 mm. Furthermore, increases in patellar flexion lower than 1 degree were observed. Small changes in retropatellar pressure were also observed.

CONCLUSION

The shortening of the patellar tendon due to tendon removal, as already suggested in several previous studies, is not attributed to the removal of the central portion of the tendon itself, but more likely due to secondary scarring contraction of the tissue. The changes of the patellarkinematics and the retropatellar pressure observed in this study are probably not of any clinical significance.

[Injury patterns and typical stress situations in paragliding]

Paragliding is known as a high risk sport with a substantial rate of severe and fatal injuries. Analysis of typical injury mechanisms and statistics showed that the total rate of paragliding injuries has decreased in recent years for an increasing number of pilots. In 2003, the rate of severe and fatal injuries in paragliding was less than that of other air sports and motorcycling. Through the introduction of a spine protector system in Germany and Austria, the number of vertebral fractures decreased significantly between 2000 and 2003. Most other injuries, especially of the lower extremities, could be avoided by adequate and farsighted flight behavior. Qualified instruction with regular training, standardized development of safety equipment and consequent analysis of paragliding injuries will help to improve the safety status in paragliding.

Patellofemorales Schmerzsyndrom

The patellofemoral pain syndrome is of high socioeconomic relevance as it most frequently occurs in young working patients. As its etiology is often unknown there is no standard treatment protocol. Several studies analyzed the different causes of patellofemoral pain and their different therapies. Static problems (pes planovalgus, instabilities, leg length differences) or chronic overuse of the knee extensor mechanism have to be identified and treated. After exclusion of intra-articular pathologies, the treatment of patellofemoral pain syndrome begins with conservative management. Stretching of the flexor and extensor muscles and training of the quadriceps muscle are the main approaches. If conservative treatment fails and patellofemoral pain persists, there are several surgical procedures for realignment of the patella in the trochlear groove and reduction of the patellofemoral pressure. Overweight patients exhibit chronic mechanical overuse of the patellofemoral joint. This leads to a higher rate of cartilage degeneration and problems at the inserting tendons and stabilizing tissues.

Trapezius transfer in brachial plexus palsy

Between March 1994 and June 2003, 80 patients with brachial plexus palsy underwent a trapezius transfer. There were 11 women and 69 men with a mean age of 31 years (18 to 69). Before operation a full evaluation of muscle function in the affected arm was carried out. A completely flail arm was found in 37 patients (46%). Some peripheral function in the elbow and hand was seen in 43 (54%). No patient had full active movement of the elbow in combination with adequate function of the hand. Patients were followed up for a mean of 2.4 years (0.8 to 8). We performed the operations according to Saha’s technique, with a modification in the last 22 cases. We demonstrated a difference in the results according to the pre-operative status of the muscles and the operative technique.

The transfer resulted in an increase of function in all patients and in 74 (95%) a decrease in multidirectional instability of the shoulder. The mean increase in active abduction was from 6° (0 to 45) to 34° (5 to 90) at the last review. The mean forward flexion increased from 12° (0 to 85) to 30° (5 to 90).

Abduction (41°) and especially forward flexion (43°) were greater when some residual function of the pectoralis major remained (n = 32). The best results were achieved in those patients with most pre-operative power of the biceps, coracobrachialis and triceps muscles (n = 7), with a mean of 42° of abduction and 56° of forward flexion. Active abduction (28°) and forward flexion (19°) were much less in completely flail shoulders (n = 34).

Comparison of the 19 patients with the Saha technique and the 15 with the modified procedure, all with complete paralysis, showed the latter operation to be superior in improving shoulder stability. In all cases a decrease in instability was achieved and inferior subluxation was abolished.

The results after trapezius transfer depend on the pre-operative pattern of paralysis and the operative technique. Better results can be achieved in patients who have some function of the biceps, coracobrachialis, pectoralis major and triceps muscles compared with those who have a complete palsy. A simple modification of the operation ensures a decrease in joint instability and an increase in function.

Die Therapie des inkompletten Meniskusrisses beim Sportler

PURPOSE

Arthroscopic treatment of complete meniscal lesions is well established. Nevertheless there is discussion, how to treat incomplete meniscal tears, especially in younger and active patients. This study was designed to evaluate our standard-therapy without refixation of the meniscus.

METHOD

Between 7/89 and 3/01 in 47 patients (48 knees, Ø age 29 years) an incomplete meniscal lesion following sports injury was found. The lesions were revitalized by "needling" or shaving. We performed no refixation. All patients had a postoperative flexion limit in an orthosis for 6 weeks. The follow-up examination was performed 6.5 (2 - 14) years postoperative.

RESULTS

The avarage Lysholm-Score increased significantly from 55 points preoperative to 92 points at the follow-up examination. The Tegner-Score increased from 3.3 points preoperative to 6.2 points at the follow-up examination. The overall result was rated "exellent" and "good" by 83 % of the patients, "fair" by 15 % of the patients and "poor" by 2 % of the patients. Return to sports activity was possible at an avarage of 7 (3 - 12) months postoperative.

CONCLUSIONS

In summary we found, that shaving and "needling" of an incomplete meniscal lesion in combination with partial synovectomi and standardized postoperative treatment leads to a high healing rate. A limited flexion for 6 weeks postoperativ in an orthosis at full weight bearing is recommended. In case of complete healing of the lesion the chondroprotective and joint stabilizing function of the meniscus, especially in young and active patients is obtained.

[Shoulder arthrodesis. Indications, techniques, results, complications]

Besides the paralysis of shoulder muscles, large rotator cuff tears beyond repair, persistent shoulder instability with repeat dislocations and resection cases are recent indications for shoulder arthrodesis. The fusion of the shoulder is particularly useful since, despite immobilization of the glenohumeral and acromiohumeral joints, no loss of function is experienced; on the contrary, in many cases an increase of active total mobility may occur. According to the functional outcome, the majority of reports vary between 30 degrees and 90 degrees of active abduction and forward flexion with a mean value of about 60 degrees The most generally accepted arthrodesis position is 20 degrees -40 degrees abduction, forward flexion and internal rotation in relation to the trunk. This position results in a maximum development of muscle power and ensures that the arm will rest comfortably at the side, and that the scapula will not protrude. This also allows the hand to reach the head and facial region. The literature is not confined to any uniform type of arthrodesis and it would appear that the techniques and configurations of material vary considerably. A general advantage of any one particular form of arthrodesis, and the use of plates, screws or external fixators, cannot be deduced. Pseudarthrosis appears to be less frequent in cases of plate arthrodesis compared to screw arthrodesis. However, the application of plates more often results in infections, postoperative fractures of the humerus and the necessary removal of material. Screw arthrodesis is more beneficial in that the exposed area to be operated is smaller than in plate arthrodesis. Postoperative immobilization is more time consuming and, therefore, constitutes one of the disadvantages of screw fixation.

[The brachial plexus lesion. Management, consequences of palsy and reconstructive operations]

The treatment of traumatic brachial plexus lesions follows sequential steps. After acute therapy (phase I), neurological diagnostics (phase II), neurosurgery and postoperative treatment (phase III/IV), reconstructive operations (phase V) can be indicated and performed. In most cases an insufficient grade of muscle power remains. Within 6 months after injury, neurosurgery must be performed in patients with brachial plexus palsy. After malfunction of the muscles, taking into account the individual neuromuscular defects, passive joint function and bony deformities, different procedures such as muscle transposition, arthrodesis and corrective osteotomy can be performed to improve the function of the upper extremity. The treatment of patients suffering from brachial plexus lesion requires interdisciplinary teamwork.

H�ftarthroskopie

Arthroscopy of the hip has become a well-established procedure for minimally invasive therapy of hip disorders. The surgical technique is demanding. A fracture table for distraction of the joint is required, as well as an exact positioning technique is most important. Because of eh great distance between skin and joint only restrictive intrarticular maneuvers are possible. Arthroscopically the hip can be divided into a central and peripheral compartment. For arthroscopy of the central compartment distraction of the joint is necessary. This part comprises the loaded surface of the femoral head and the lunate cartilage. The peripheral compartment consists of the unloaded cartilage of the femoral head and the femoral neck until the capsular insertion. This compartment can be visualized without traction. Good results can be achieved in the therapy of labral lesions, loose bodies, moderate osteoarthritis, synovial diseases and pathology of the teres ligament. Performing hip arthroscopy in an adequate technique and under consideration of contraindications, complications are rare.

[Open versus arthroscopic shoulder stabilization. An analysis of the treatment costs]

In this study the total costs of clinical open and arthroscopic anterior shoulder stabilization were evaluated, analyzed and compared. From 1988 to 1998 147 patients underwent open (Bankart) or arthroscopic (ASK) anterior shoulder stabilization. We randomized two groups of 30 patients for each method (Bankart: 25 male, 5 female, 29 years of age; ASK: 25 male, 5 female, 26 years of age) and evaluated the costs of their clinical treatment. The total cost was significantly ( p<0.05, Mann-Whitney U-Test) higher for the open (5639 euro) than for the arthroscopic (4601 euro) therapy. There was a significant difference between the groups for the average cost of surgery (Bankart: 2741 euro; ASK: 2315 euro, p<0.05) and the average postoperative treatment cost (Bankart: 2202 euro; ASK: 1630 euro, p<0.05) whereas the average preoperative treatment cost was not significantly different (Bankart: 669 euro, ASK: 657 euro). The staff costs for the surgical procedure (Bankart: 1800 euro (32%), ASK: 1319 euro (29%)) and the postoperative staff costs of the nurses (Bankart: 1271 euro (23%), ASK: 997 euro (22%)) represented the greatest parts of the total costs. The average duration of the clinical treatment was 15.8 days for the open- and 12,4 days for the arthroscopic group.

[Arthroscopic anterior shoulder stabilization combined with laser-assisted capsular shrinkage (LACS) compared to other procedures]

INTRODUCTION

Does additional laser assisted capsular shrinkage (LACS) help to reduce the recurrence rate in arthroscopic anterior shoulder stabilization?

METHODS

In a prospective study from 7/97 to 4/99 at 22 nonselected patients a combined Caspari + LACS-technique was performed. We could follow-up 152 (80%) of a total 191 anterior shoulder stabilizations between 4/88 and 4/99 (124 male, 28 female, average age 33 years) (80(52%) Bankart, 30(20%) Du Toit/Roux, 20(13%) Caspari, 22(15%) Caspari + -LACS.

RESULTS

The rate of dislocation was 7% (11/152) for all patients (Bankart 5% 4/80), Du Toit/Roux 4% (1/30), Caspari 25%(5/20), Caspari + LACS 5%(1/22)). Using the score of Rowe et al. [34] 113 patients (75%) rated excellent or good (Bankart 77%, Du Toit/Roux 83%, Caspari 60%, Caspari + LACS 86%).

CONCLUSIONS

An additional laser capsular shrinkage helps to reduce the high rates of dislocation in arthroscopic anterior shoulder stabilization with results similar to standard open procedures.

[Shoulder arthrodesis with plate fixation. Special features in cases of resection and defects]

AIM

Shoulder arthrodesis following prosthesis explantation or resection of the acromion has not often been described in the literature. The presented article analyses the special features and problems of these preoperative circumstances in 4 cases and discusses them within the entire group.

PATIENTS AND METHOD

Between 06/1987 and 02/2001, a total of 30 shoulder arthrodeses using plate fixation were performed in our clinic and then analysed after an average of 2.7 (0.5 - 8.7) years. Surgery was carried out on 5 (17 %) females and 25 (83 %) males with a mean age of 37 (17 - 82) years. Two patients underwent shoulder arthrodesis as a salvage operation following unsatisfactory arthroplasty, or after trapezius transfer with corresponding reduced bony conditions, respectively.

RESULTS

The active extent of movement following arthrodesis was 56 degrees (20 degrees - 90 degrees ) abduction, and 60 degrees (20 degrees - 105 degrees ) anteversion. The most frequent complications following arthrodesis included pseudarthroses (3/10 %), infections (4/13 %), and fractures of the humerus (4/13 %). The rate of complications was especially high in the cases after explantation of a shoulder prosthesis and resection of the acromion. In two of the four patients, three or five revision operations, respectively, were necessary. Two of the three pseudarthroses of the entire group occurred in these two cases.

CONCLUSION

Complications of shoulder arthrodesis after resection of the acromion or the proximal humerus are especially frequent. To avoid pseudarthrosis in such cases, primary spongioplasty is advantageous. A fixation with plates is superior to a simple screw arthrodesis. For postoperative immobilization a plaster cast instead of an orthotic device should be taken into consideration.

[The influence of age on the outcome of anterior cruciate ligament reconstruction]

AIM

There is an increasing demand for a high loading capacity of the knee during exercise in the elderly patient with knee instability following rupture of the anterior cruciate ligament (ACL). The question is, if the results of an ACL reconstruction in patients over 40 years of age are as good as those in younger patients.

METHOD

From 1989 to 1994 we replaced the ACL with a mid-third BPTB autograft in 397 patients following ACL rupture. A total of 309 patients (78%, 110 female, 199 male, the average age was 27 years) were followed for an average of 43 months. The results were compared relating to four groups of age (group 1: < 20 years, n = 41; group 2: 20 - 29 years, n = 175; group 3: 30 - 40 years, n = 77; group 4: > 40 years, n = 16).

RESULTS

We did not find any significant differences between the groups in the different score ratings, the subjective and objective knee function and stability, the pain and the level of activity. The average Cincinnati score of the whole group was 91 points (HSS score: 78/16 % excellent/good, Lysholm score: 90 points, IKDC score: 22/31 % A/B).

CONCLUSION

ACL replacement is a sufficient therapy for patients over 40 years of age with symptomatic knee instability following ACL rupture. The subjective and objective clinical outcome is comparable to the good results of ACL replacement in younger patients without any significant differences.

[Corrective bone operations for treatment of deformities caused by obstetrical brachial plexus palsy]

In an adult, a marked deformity of the upper arm and forearm with loss of function of the limb due to obstetrical brachial plexus palsy has been corrected. An external rotational osteotomy of the humerus and radioulnar arthrodesis resulted in an improved function.

[Radiologic and computerized tomography evaluation of pedicle screw placement in lumbar spondylodesis]

PURPOSE

To determine the accuracy of a standard roentgenogram for the placement control of pedicle screws following spinal fusion.

METHOD

From 1995 to 1997 we performed computed tomography (CT) after material removal following lumbar and lumbosacral spinal fusion in 16 patients. We compared the placement of the 76 pedicle screws in plain X-rays after spinal fusion with their appearance on CT. A correct placement was defined as no penetration of the pedicle cortex, no contact of the lateral or ventral cortex of the vertebral body or joint, and a sufficient screw length.

RESULTS

We found correct placement of 58 screws (76.3%) on the standard roentgenogram, whereas by CT only 46 (60.5%) were placed correctly. The results of both radiological examinations correlated (correct/incorrect placement) for only 54 screws (71.1%). A penetration of the ventral cortex of the vertebral body in 21 cases (27.6%) was identified in only 11 screws (14.5%) on the postoperative X-rays. The two radiological methods in this instance correlated for 62 screws (81.6%).

CONCLUSION

The value of postoperative standard roentgenogram for the placement control of pedicle screws following spinal fusion is low. By this method possible contact with the aorta, vena cava, dura or vertebral joint cannot sufficiently be excluded.

[Surgical shortening of the Achilles tendon for correction of elongation following healed conservatively treated Achilles tendon rupture]

INTRODUCTION

Is operative shortening of the achilles tendon an adequate therapy in cases of elongation following conservative treatment of achilles tendon rupture?

METHODS

From 11/89 to 12/97, 12 patients underwent achilles tendon shortening (9 male, 3 female, average age 43 years). All patients had an elongated tendon following conservative treatment of achilles tendon rupture. We were able to examine 8 patients (67%) after the operation. The average follow-up period was 35 (7-103) months with an average span between the primary trauma and surgery of 22 (8-45) months.

RESULTS

Prior to surgery, all patients complained of weakness, gait disturbance and limitation of activity. At follow-up a subjective weakness of the plantar flexion remained in five and an objective weakness in all patients. We found a decrease of the isometric plantar flexion strength to 52% of the non-operated lower extremity while the maximum calf circumference was only 5% decreased. Only two patients reported of a gait disturbance and activity limitation whereas three patients were free of complaints. Using a modified Trillat score (1,967), 7 patients rated good or very good (1 poor).

CONCLUSIONS

Achilles tendon shortening in case of elongation following conservative treatment of achilles tendon rupture helps to decrease gait disturbance and limitation of activity whereas a lack of the isometric plantar flexion strength persists. In our opinion an early decision for achilles tendon shortening might prevent this deficit.

The value of scintigraphy in the diagnosis of pseudarthrosis after spinal fusion surgery

The utility of planar bone scintigraphy was evaluated for discerning bony union after spinal fusion surgery, especially in cases of clinically and radiologically suggested pseudarthrosis. Between 1991 and 1996, the authors performed bone scintigraphy on 42 patients (21 women, 21 men; mean age, 42 years) after spinal fusion surgery (32 posterolateral, 10 combined) and just before their admission to the hospital for material removal. The fusions consisted of 29 lumbosacral, 6 thoracolumbar, 3 lumbar, 2 thoracolumbosacral, 1 thoracic, and 1 cervical. The mean fusion spanned four segments, and the mean time between spinal fusion and material removal was 27 months. The scintigraphy was performed using the tracer Tc-99m. Based on the scintigraphy data, the radiologist suspected pseudarthrosis in five patients (12%), and the condition was confirmed in four patients during operation (10%), two diagnosed and two undiagnosed. The accuracy of the method was 88%; sensitivity, 50%, specificity, 93%; positive predictive value, 40%; and negative predictive value, 95%. The sensitivity and positive predictive value of bone scintigraphy are low for possible instability after spinal fusion. The method is not sufficient to reliably diagnose pseudarthrosis after spondylodesis.

[Comparison of clinical examination with NMR spectroscopy in the diagnosis of meniscal lesions in daily practice]

INTRODUCTION

We investigated the value of Magnetic Resonance Imaging compared to the clinical examination for meniscal lesions.

MATERIAL AND METHODS

From 1991 to 1995 we did arthroscopic evaluation at 824 patients with the diagnose "meniscal lesion". 73 of them had an MRI-examination elsewhere before surgery.

RESULTS

During arthroscopy we found 473 lesions of the medial meniscus and 160 of the lateral meniscus. The MRI-examination had an accuracy of 70% for the medial meniscus (sensitivity 79%, specificity 63%, positive predictive value 64%, negative predictive value 78%) and 78% for the lateral meniscus (sensitivity 50%, specificity 86%, positive predictive value 50%, negative predictive value 86%). The clinical examination had an accuracy of 73% for the medial meniscus (sensitivity 98%, specificity 39%, positive predictive value 69%, negative predictive value 88%) and 87% for the lateral meniscus (sensitivity 67%, specificity 92%, positive predictive value 65%, negative predictive value 93%).

CONCLUSIONS

We conclude, that by an experienced examiner a meniscal lesion can be diagnosed adequately by clinical examination alone. The different radiologists who did the MRI examination in our study belong to different outward departments and used different apparatus with sometimes insufficient quality of the pictures. Therefore the sensitivity and specificity of the MRI for meniscal lesions is markedly lower than in other studies of departments where a close cooperation between the radiologist and the orthopedic surgeon is performed.