[Significance of the hypoechoic area around the long biceps tendon in shoulder sonography--underlying pathology]

OBJECTIVE

The objective was to evaluate the sonographic sign of a hypoechoic area ("halo-sign") around the long biceps tendon as an equivalent of intraarticular effusion.

METHODS

Part 1: Ten patients scheduled for shoulder arthroscopy underwent ultrasonography immediately before surgery. If there was no hypoechoic area around the long biceps tendon 30 ml of NaCl-solution (0.9%) were injected into the joint. After repetitive passive motion the patient underwent a second ultrasonography. Part 2: Ten consecutive patients with a hypoechoic area around the long biceps tendon underwent shoulder arthroscopy. During this procedure they were examined for intraarticular effusion. Patients with rheumatoid disease were excluded from the study.

RESULTS

Part 1: In 9 of 10 patients a hypoechoic area around the long biceps tendon was induced by injection into the joint. The area was 1.07 +/- 0.13 cm2. In one case we could not induce the described phenomenon. Part 2: In all patients with a hypoechoic area around the long biceps tendon an intraarticular effusion was found at arthroscopy.

CONCLUSION

A hypoechoic area around the long biceps tendon correlates with fluid in the synovial sheet and indicates effusion within the glenohumeral joint.

Comparison of initial fixation strength between biodegradable and metallic interference screws and a press-fit fixation technique in a porcine model

The objective of this study was to evaluate the initial fixation strength of a biodegradable interference screw compared with press-fit fixation and a titanium interference screw in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. The specimens underwent 500 loading cycles between 60 and 250 N. This corresponds to loads in the graft during aggressive rehabilitation. Thereafter, intact specimens were loaded to failure. Failure mode was defined by visual analysis. Under cyclic loads none of the interference screw fixations failed. In the press-fit group (angle between load axis and tunnel axis 80 degrees), five specimens failed. The mean maximal load to failure was 945 N (+/- 87) for the titanium screw, 797 N (+/- 60) for the biodegradable screw, and 708 N (+/- 211) for the five press-fit specimens that did not fail during cyclic loading. With respect to primary fixation strength, biodegradable screws are a reasonable alternative to titanium interference screws. The press-fit fixation did not provide a secure fixation in all cases. Five press-fit specimens failed under cyclic loads comparable with those seen under conditions of accelerated rehabilitation.

Sports injuries in team handball. A one-year prospective study of sixteen men's senior teams of a superior nonprofessional level

One hundred eighty-six players of 16 teams in 2 male team handball senior divisions were observed prospectively for 1 season to study the injury incidence in relation to exposure in games and practices. Ninety-one injuries were recorded. Injury incidence was evaluated at 2.5 injuries per 1000 player-hours, with a significantly higher incidence in game injuries (14.3 injuries per 1000 game-hours) compared with practice injuries (0.6 injuries per 1000 practice-hours). Practice injury incidence was higher in the lower performance level group, and game injury incidence was higher in the high-level group. The upper extremity was involved in 37% of the injuries, and the lower extremity in 54%. The knee was the most commonly injured joint, followed by the finger, ankle, and shoulder. Knee injuries were the most severe injuries, and they were more frequent in high-level players. There was an increase in the severity of injury with respect to performance level. The injury mechanism revealed a high number of offensive injuries, one-third of them occurring during a counterattack. The injury pattern showed certain variations with respect to player position and performance level. Prophylactic equipment was used by a majority of players at the higher performance level.

Cortical versus cancellous interference fixation for bone-patellar tendon-bone grafts

The objective of this study was to evaluate the initial fixation strength of a metal interference screw (9 x 25 mm; Arthrex, Naples, FL) with respect to its position relative to the bone plug in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. In group 1 (n = 20) the screw was placed adjacent to the cortex of the bone plug. In group 2 (n = 20) the screw was placed between the cancellous surfaces of the tibial tunnel and the bone plug. Specimens were loaded to failure using an universal material testing machine. Failure mode was defined by visual analysis of the specimens after loading. Primary fixation strength was not significantly different for both groups. Maximum force was 779 +/- 179 N (group 1, cortical side) and 743 +/- 143 N (group 2, cancellous side). There was a difference in failure modes. In group 1, testing resulted predominantly in tendon ruptures and bone plug fractures (70%). In group 2, bone plug pullouts were predominant (75%). From these data we conclude that the position of the screw relative to the bone plug influences failure mode but not the initial fixation strength.

Preoperative ultrasonographic mapping of calcium deposits facilitates localization during arthroscopic surgery for calcifying tendinitis of the rotator cuff

Calcifying tendinitis is a relatively common disorder of the rotator cuff. For symptomatic patients, excision of the calcium deposits offers reliable pain relief. The arthroscopic technique is demanding. Arthroscopic localization of the deposit is frequently demanding. The technique described in this article facilitates the localization of calcium deposits based on preoperative ultrasonography. Knowing the exact topography of the deposit relative to the visible landmarks allows the surgeon to localize the site of the deposit from the intra-articular view. Probing the rotator cuff with a spinal needle and looking for calcific material at the tip of the needle is an important step in verifying the location of the deposit.

Surgical reconstruction of a stress fracture of the acromion after arthroscopic subacromial decompression in an elite tennis player

We report the case of a stress fracture of the acromion after arthroscopic subacromial decompression in a 31-year-old female elite tennis player. The fracture was treated successfully by surgical reconstruction using two parallel Kirschner wires and a tension band.

Gpa2p, a G-protein alpha-subunit, regulates growth and pseudohyphal development in Saccharomyces cerevisiae via a cAMP-dependent mechanism

The small GTP-binding protein Ras and heterotrimeric G-proteins are key regulators of growth and development in eukaryotic cells. In mammalian cells, Ras functions to regulate the mitogen-activated protein kinase pathway in response to growth factors, whereas many heterotrimeric GTP-binding protein alpha-subunits modulate cAMP levels through adenylyl cyclase as a consequence of hormonal action. In contrast, in the yeast Saccharomyces cerevisiae, it is the Ras1 and Ras2 proteins that regulate adenylyl cyclase. Of the two yeast G-protein alpha-subunits (GPA1 and GPA2), only GPA1 has been well studied and shown to negatively regulate the mitogen-activated protein kinase pathway upon pheromone stimulation. In this report, we show that deletion of the GPA2 gene encoding the other yeast G-protein alpha-subunit leads to a defect in pseudohyphal development. Also, the GPA2 gene is indispensable for normal growth in the absence of Ras2p. Both of these phenotypes can be rescued by deletion of the PDE2 gene product, which inactivates cAMP by cleavage, suggesting that these phenotypes can be attributed to low levels of intracellular cAMP. In support of this notion, addition of exogenous cAMP to the growth media was also sufficient to rescue the phenotype of a GPA2 deletion strain. Taken together, our results directly demonstrate that a G-protein alpha-subunit can regulate the growth and pseudohyphal development of S. cerevisiae via a cAMP-dependent mechanism. Heterologous expression of mammalian G-protein alpha-subunits in these yeast GPA2 deletion strains could provide a valuable tool for the mutational analysis of mammalian G-protein function in an in vivo null setting.

[Shoulder arthrodesis in deltoid paralysis]

After loss of active glenohumeral motion the arm cannot be positioned in space and function is impaired. Fusion of the glenohumeral joint creates a new platform for the movement of elbow, hand and fingers and leads to an improvement of function. The use of the reconstructive plate makes the operation easier. Shoulder fusion is especially suited if the function of elbow and hand is well preserved and if the patient is physically active. But fusion is definite and the options of muscle transfer operations and above elbow amputation have to be considered.

Arthrodesis of the glenohumeral joint for deltoid palsy

After loss of active glenohumeral motion the arm cannot be positioned in space and function is impaired. Fusion of the glenohumeral joint creates a new platform for the movement of elbow, hand and fingers and leads to an improvement of function. The use of the reconstructive plate makes the operation easier. Shoulder fusion is especially suited if the function of elbow and hand is well preserved and if the patient is physically active. But fusion is definite and the options of muscle transfer operations and above elbow amputation have to be considered.

[Injuries during handball. A comparative, retrospective study between regional and upper league teams]

To evaluate the injuries in Team Handball 186 male players out of 16 teams were questioned retrospectively at the end of a season. An important difference between practice and competition injuries could be found with an injury rate of 0.8 injuries per 1000 training hours and 13.5 injuries per 1000 playing hours. Injuries were predominant at the lower extremities with ankle injuries being the most frequent injury type. 2/3 of the playing injuries occurred in offense. 1/3 of these offense injuries could be attributed to a counter-attack. These injuries were generally more severe which lead us to a proposition of changing the rules of the game in foul plays in this situation. Elbow injuries in goalkeepers and shoulder injuries in throwers were specific for these types of players. Prophylactic braces were used by nearly 2/3 of the players.

Fixation strength of a biodegradable interference screw and a press-fit technique in anterior cruciate ligament reconstruction with a BPTB graft

The objective of this study was to evaluate the fixation strength of a biodegradable interference screw (Arthrex, Naples, FL) compared with press fit fixation and a titanium interference screw in anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) graft. Porcine lower limbs were used. Ultimate failure loads of the biodegradable screw (805.2 N; range 680 to 995 N) did not differ significantly from ultimate failure loads of titanium interference screws (768.6 N; range 544 to 1094 N). Press fit fixation provided significant (P < .01) lower fixation strength (462.5 N; range 80 to 825 N). These results support the conclusion that biodegradable interference screws are a reasonable alternative in terms of primary fixation strength.

Use of preoperative vascular embolisation in spinal metastasis resection

Preoperative selective embolisation was carried out on 17 patients with spinal metastases from various primary tumours. There was a significant reduction in the blood loss (2088 ml) and infusion volume requirement (3500 ml) and more favourable postoperative haemoglobin (Hb) development compared with the non-embolised but otherwise identical control group. The reduced intraoperative bleeding manifested itself in the form of greater clarity and a less complicated intraoperative course. Particularly with a dorsal approach, the reduced bleeding permitted more exact preparation and more extensive tumour resection. Preoperative embolisation is thus a valuable aid in spinal metastasis resection. Given suitable indications and exact positioning of the embolising material, no significant complications should arise. The method as a whole calls for close collaboration between interventional radiologists and spinal orthopaedists.

[Cruciate ligament injuries with knee joint effusion--why can the Lachman sign not be elicited?]

In acute anterior cruciate ligament (ACL) lesions with effusion of the knee joint it is often difficult to realize a positive Lachman sign. It was suggested that the tension of the joint capsule may reduce tibial displacement although the ACL is completely disrupted. In 10 cadaver knee joints the ACL was dissected and the capsule was closed again. By a canula the knee joints were filled with isotonic saline solution in steps of 20 ml up to 100 ml. Before and after dissection of the ACL and during filling the joint we measured the anterior tibial displacement by use of the MEDmetric KT 1000 arthrometer. In a second series we examined 5 patients with acute effusion of the knee joint before and after puncture of the effusion. We detected the electromyographic activity of the quadriceps muscle end and the hamstrings during the KT 1000 test and patellar reflex. In the cadaver tests we found no reduction of the anterior tibial translation while filling the joint with saline solution. The electromyographic examinations showed a reflectory action in the quadriceps muscle and in the hamstrings when the Lachman test was performed. In the quadriceps muscle the electromyographic amplitude was reduced after puncture; the hamstrings showed a drastically reduced amplitude and duration of the signal. When patellar reflex was performed we recorded an electromyographic action in both muscle groups, too. Puncture could only reduce the signals of the hamstrings. Our results suggest that the reduction of the anterior drawer and the Lachman test in acute effusion is caused not mechanically by the tension of the capsule but by a reflectory muscle action of the hamstrings.

[Mechanical properties of new low viscosity bone cements--can be improved by vacuum mixing]

With the objective of improving mechanical properties by using a new catalyst, a new bone cement (Sulfix-60) and a new low-viscosity cement with added gentamycin (Allofix-G) were developed. Dynamic weakness was the major disadvantage of the older Sulfix-6 cement, especially in comparison with high-viscosity bone cement. Although static strength could be improved, investigations into improved fatigue strength and the effect of vacuum-mixing on the static and fatigue strength had yet to be carried out. To investigate fatigue stability specimens of the new bone cements were tested using loads under wet conditions until breakage or 20 million cycles. In a first series the cement was hand-mixed in a second series vacuum-mixed alone, and in a third series vacuum-mixed under pressure. Additionally, the ultimate static bending strength was investigated using the standard four-point bending test for the three series of bone cement. Vacuum-mixing brought about an improvement in the dynamic strength of Sulfix-60 from 6.3 MPa, to 9.1 MPa and for Allofix-G from 6.3 MPa to 8.2 MPa; additional pressure brought no further improvement. A 200% increased fatigue stability was detectable in comparison with the older cement. The ultimate bending strength was also significantly improved by vacuum-mixing for both bone cements.

The failed back surgery syndrome: reasons, intraoperative findings, and long-term results: a report of 182 operative treatments

STUDY DESIGN

A retrospective study was performed of 182 revisions on failed back surgery syndrome from the years 1965 to 1990.

OBJECTIVE

To analyze the reasons for failure of primary discectomy, the outcome of the revisions, and factors that influenced those outcomes.

SUMMARY OF BACKGROUND DATA

The reported reintervention rates after lumbar discectomy range from 5% to 33% depending on the type of surgical procedure. The authors' former investigations reported a revision rate of 10.8% in evaluating 1500 lumbar discectomies.

METHODS

Because the documentation was standardized, detailed data of all patients were available. To gain further information concerning the long-term results a questionnaire was used. Computer processing and statistical tests were performed.

RESULTS

One hundred eighty-two revisions were performed on 136 patients. Forty-four patients (34%) were revised multiple times. Generally, recurrent or uninfluenced sciatic pain and neurologic deficiency or lumbar instability led to reintervention. Recurrent lumbar disc herniation mainly was found at the first reintervention. In multiple revision patients the rate of epidural fibrosis and instability increased to greater than 60%. In 80% of the patients the results were satisfactory in short-term evaluation, decreasing to 22% in long-term follow up (2-27 years).

CONCLUSIONS

Laminectomy performed in primary surgery could be detected as the only factor leading to a higher rate of revisions. A trend toward poor results after recurrent disc surgery seems to be fateful because of the development of epidural fibrosis and instability. In severe discotomy syndrome, a spinal fusion seems to be more successful than multiple fibrinolyses.

Does vacuum-mixing improve the fatigue properties of high-viscosity poly(methyl-methacrylate) (PMMA) bone cement? Comparison between two different evacuation methods

The objective was to verify different reports in the literature which show an increase of stability using vacuum-mixing of bone cement, by testing the fatigue properties of bone-cement specimens (Palacos R). Evacuation of the poly(methyl-methacrylate) (PMMA) and evacuation with additional pressurization (Draenert system) were used to manufacture the specimens. Although we found improvement in the ultimate bending strength for evacuated Palacos R, an increase of fatigue stability could not be found either for vacuum-mixed cement or for vacuum-mixed and compressed cement. As fatigue failure is one of the most important factors leading to aseptic loosening of cemented alloarthroplasties, we conclude that the long-term results cannot be improved by vacuum-mixing this cement.

[Clinical relevance of tunnel position and interference screw location after replacement-plasty of the anterior cruciate ligament with a patellar ligament transplant]

Fifty-eight patients had a prospective follow-up examination 1 year after arthroscopic ACL replacement. Stability measurement was done using a KT-1000 arthrometer. The side-to-side difference was less than 2 mm in 40 patients, 2-4 mm in 11 patients and more than 4 mm in 7 patients. The position of the tibial and femoral tunnels and interference screw was measured from the postoperative X-ray. The positions of screws and tunnels were highly variable. However, there was no statistical correlation between the position of the femoral interference screw and stability measurement or between the position of the femoral interference screw and flexion contracture or between the position of the tibial interference screw and the extension contracture. However, out of six patients with the femoral tunnel in an extremely anterior position (> 20 mm anterior of the over the top position), only one patient had a stable joint (< 2 mm difference in KT 1000 with 89 N anterior shear load) at follow-up. A screw divergence of more than 10 degrees was found in 18 patients. A tibial interference screw with more than 30 degrees of divergence was seen in seven patients. The primary fixation strength of the bone block could be diminished in these cases. This may have an impact on the early rehabilitation protocol.

Shoulder problems in high level swimmers--impingement, anterior instability, muscular imbalance?

The objective was to study prevalence and underlying pathology of "swimmer's shoulder". Twenty-two competitive swimmers of national "D-Kader" (elite development swimmers) were evaluated by means of questionnaire, clinical examination and isokinetic testing of external rotation and internal rotation. At the examination current interfering pain necessitating a cessation or reduction of practice was found in 5 (23%) athletes. At isokinetic testing 8 (36%) athletes complained of shoulder pain. Any history of pain was seen in 14 (64%) swimmers. A positive impingement sign was noted in 11 (50%) athletes. Apprehension sign which is indicative of anterior instability was found in 11 (50%) swimmers. Clinical equivalents of dysfunction of scapulothoracic muscles such as scapular winging (5 athletes) and shoulder protraction (12 athletes) were noted. For comparison of results of isokinetic testing a control group of non-swimmers was selected matching the group of swimmers exactly in terms of age, sex and dominant side. External rotation/internal rotation ratio of peak torque and total work at 60 deg/sec and 180 deg/sec was significantly lower in swimmers than in controls. The ratio was independent of sex, dominant side, history of pain and pain at examination. During internal rotation competitive swimmers produced significantly higher peak torques and total work than controls. There was no significant difference in external rotation. In conclusion there are several different abnormalities of function contributing to the pathology of "swimmer's shoulder":--Laxity of anterior-inferior capsuloligamentous structures with atruamatic anterior instability due to repetitive overload.--Impingement with rotator cuff tendinitis.--Muscular imbalance of the rotator cuff muscles and scapulothoracic dysfunction.

[Reduction of the anterior drawer of the knee joint by rehabilitation orthoses. Comparison of the MVP orthosis vs. the Donjoy-Gold point orthosis]

In 20 patients with chronic anterior instability of one knee, two rehabilitation braces (MVP, Donjoy-Gold point) were tested for their ability to limit tibiofemoral translation. A KT-1000 arthrometer was used to quantify the anterior drawer. Both braces significantly reduced passive anterior drawer at 67 N, 89 N and maximal manual shear load and also active anterior drawer. Without a brace the mean anterior drawer was 12.3 mm (67 N), 14.4 mm (89 N), 17.2 mm (maximal manual drawer) and 9.1 mm (active drawer). With the MVP brace the mean anterior drawer was 6.8 mm (67 N), 8.5 mm (89 N), 11.0 mm (maximal manual drawer) and 6.8 mm (active drawer). With the Donjoy brace the mean anterior drawer was 9.2 mm (67 N), 11.0 mm (89 N), 13.1 mm (maximal manual drawer) and 7.4 mm (active drawer). Control values for the non-injured opposite knee were 6.5 mm (67 N), 7.2 mm (89 N), 8.1 mm (maximal manual drawer) and 5.6 mm (active drawer). In direct comparison, the MVP brace provided better stabilization than the Donjoy-Gold point brace did.

Biogenesis of the yeast vacuole (lysosome). The use of active-site mutants of proteinase yscA to determine the necessity of the enzyme for vacuolar proteinase maturation and proteinase yscB stability

The activation process of vacuolar proteinases in the yeast Saccharomyces cerevisiae via precursor maturation is initiated by the PRA1/PEP4 gene product, proteinase yscA. Chromosomal deletion of the PRA1/PEP4 locus leads to accumulation of inactive pro-proteinases in the vacuole. Nine active-site mutations of proteinase yscA have been constructed in vitro. All these mutations lead to the expression of proteinase yscA species in vivo that are inactive against the in vitro substrate hemoglobin and the in vivo substrates pro-proteinase yscB and pro-carboxypeptidase yscY. However, three active-site mutations in proteinase yscA sustained the precursor maturation of proteinase yscB and carboxypeptidase yscY after exchange of the genomic wild-type allele with the respective proteinase yscA mutant alleles. In contrast to yeast strains deleted in proteinase yscA, the respective mutants carry out all cellular functions that rely on a proteolytically active vacuole. This wild-type behaviour of proteinase yscA mutant cells is dependent on the presence of active proteinase yscB. Proteinase yscA and proteinase yscB are equally able to fulfil essential cellular functions. For instance, either proteinase is able to maintain viability under starvation. However, mature proteinase yscB is not stable in the absence of proteinase yscA. The wild-type-like conformation of proteolytically inactive mutant proteinase yscA proteins stabilizes mature proteinase yscB and thus enables continuous maturation of pro-proteinase yscB by active proteinase yscB. After inhibition of the proteolytic activity of proteinase yscB in these proteinase yscA mutants with phenylmethysulfonyl fluoride or deletion of the PRB1 gene, maturation of all zymogens investigated in the vacuole, including the proteinase yscA mutant proteins, is blocked. The proteolytic activities of the vacuole in such a strain can be regained, however, by introduction of a wild-type proteinase yscA gene allowing subsequent autocatalytic maturation of wild-type pro-proteinase yscA. This indicates that an initial self-activation process of proteinase yscA is necessary for the activation of vacuolar zymogens.

[Subacromial impingement. Evaluating the concept--diagnosis--therapeutic concepts]

Subacromial impingement is a condition that belongs to the group of diseases known collectively as periarthritis humeroscapularis and has a typical clinical presentation. The underlying cause is a late of sufficient space of various origin in the subacromial region that finally leads to rotator cuff damage. Depending on cause, three forms can be distinguished, primarily extrinsic, primarily intrinsic and secondary impingement. The diagnosis is primarily clinical (pain on raising the arms above the head, painful arc syndrome). The value of imaging techniques, and the diagnostic approach are described. Initially treatment is always conservative, but when pain becomes severe or function is lost, arthroscopic or open surgical treatment may be needed.

Ultrasound of the Achilles tendon after surgical repair: morphology and function

Ultrasound is a well established method for the examination of the Achilles tendon. The objective of the study was to provide answers to the following questions: What ultrasonographic structural changes are long lasting after surgical repair? How important is ultrasound with regards to the functional evaluation of late results? 60 patients were examined at an average 11 years (2-19) after surgical repair of Achilles tendon rupture. In only four patients sonographic morphology of the tendon was according to the non-injured side. A variety of distinct basic alterations in ultrasound morphology was found: a hypoechogenic ribbon ventrally to the dorsal paratenon (n = 40), spots of hypoechogenic areas in the tendon (n = 18), dishomogeneous hyperechogenicity with preservation (n = 12) or dissolving (n = 22) of its fibrillar components along the longitudinal axis. In most of the cases the paratenon was thickened or could not be differentiated. In the dynamic ultrasound examination gliding mechanism of the achilles tendon was limited in 41 patients. Extensive functional subjective and objective parameters of all patients were evaluated in an Achilles tendon score. The results were rated as excellent (n = 18), good (n = 29), satisfactory (n = 12) and poor (n = 1). There was no statistical correlation between ultrasound morphology and clinical outcome. Therefore, it was concluded that ultrasound examination is able to reveal long-lasting alterations in echogenicity of the tendon but is only of limited value with regards to evaluation of the functional results after surgical repair.

Arthroscopic surgery of the elbow. Therapeutic benefits and hazards

In this study, 22 patients were reviewed who underwent arthroscopic surgery of the elbow mainly for loose bodies or osteochondrotic lesions. Of these, 12 patients rated the result as good or excellent, 4 had slight improvement, and 6 were not satisfied. The average score (Hospital of Special Surgery scoring system; maximum 100 points) was raised from 70 points to 87 points after surgery. Patients with loose bodies in the elbow and no severe damage of the articular cartilage benefitted most. The results in patients with marked degenerative changes differed considerably.

[Biomechanical principles of after-care in replacement of the anterior cruciate ligament]

The patellar tendon graft replacing the anterior cruciate ligament undergoes histomorphological and biomechanical changes. From literature we can estimate a force of 200 N to be a critical limit of graft load after ACL-plasty in humans. The comparison with the graft loads under various conditions provided the following conclusions: Unlimited passive motion of the knee joint can be done without risk. Early weight bearing is possible. Active extension exercise against gravity could damage the graft in the range of 0 to 20 degrees of flexion in some patients. A rehabilitation protocol has to regard these biomechanical principles. In a prospective study 74 patients underwent rehabilitation according to the protocol described. An extension contracture of more than 10 degrees was seen in 9 patients. In all cases it was due to a notch-impingement or a cyclops. One year after operation 57 patients had a follow up. The side to side-difference in anterior drawer measured with a KT-1000-arthrometer was less than 2 mm in 45 patients. Six patients had difference between 2 and 4 mm. In six patients the difference was more than 4 mm.

[Arthrofibrosis after replacement-plasty of the anterior cruciate ligament--incidence, causes, therapy]

The objective of the study was to assess prospectively the percentage of patients with restricted range of motion (arthrofibrosis) after ACL-plasty and to assess the clinical benefit of arthroscopic surgery. We had arthrofibrosis in 9 out of 74 cases (12%). In 8 cases there was a combined lag of flexion and extension and in one case there was only a lag of extension. In all patients range of motion could be improved by arthroscopic surgery. There was a significant raise in extension (13.3 degrees) and in flexion (28.7 degrees). In the arthrofibrosis-group more patients had undergone surgery for acute ACL-rupture (66%) than in the group without arthrofibrosis (32%).

[Delayed management of rupture of the Achilles tendon. Long-term follow-up in comparison with early operation]

At the Orthopedic Clinic of the University Homburg/Saar 32 delayed (8 days to 7 months) treated ruptures and 32 immediately (< 48 hours) treated ruptures of the Achilles tendon were followed up by clinical tests and sonographic examination and were compared with regard to the final results and the complications. There was no significant difference in the functional results. The rate of complications, which made a second operation necessary, was significantly higher in the group of delayed repair of the Achilles tendon rupture.

[Functional orthoses in insufficiency of the anterior cruciate ligament. Biomechanical comparative studies in vivo and with a model]

We tested 4 functional braces for anterior cruciate ligament insufficiency (CTI, Lennox Hill, Ultratech, Proshifter) in vitro and in vivo. In vitro all braces limited the anterior drawer. The maximal anterior drawer was 3.08 mm (CTI), 5.16 mm (Ultratech), 6.25 mm (Lennox-Hill), 7.33 mm (Proshifter). In vivo anterior drawer was controlled at low shear loads (67 N). With high shear loads the anterior drawer was significantly reduced but the tibiofemoral translation was significantly reduced but the tibiofemoral translation was higher than in the uninjured knee. Without brace: 16.25 mm; CTI: 10.15 mm; Ultratech: 12.10 mm; Lennox-Hill: 9.80 mm; Proshifter: 12.75 mm;

CONTROL

8.05 mm. The active anterior drawer was reduced but not normalized by all braces. Without brace: 8.75 mm; CTI: 5.35 mm; Ultratech: 5.6 mm; Lennox-Hill: 5.45 mm; Proshifter: 6.75 mm;

CONTROL

4.25 mm. None of the braces tested could control the rotation efficiently.

Lateral tibial avulsion fractures and disruptions to the anterior cruciate ligament. A clinical study of their incidence and correlation

Avulsion fractures of the lateral tibial plateau, known as the lateral capsular sign, are increasingly associated with anterior cruciate ligament (ACL) ruptures. This phenomenon, known as the Ségond fracture, is a bony avulsion of the menisco-tibial ligament. Stress, which can lead to an avulsion of this kind, almost always occurs during knee flexion and internal tibial rotation, and in most cases only after damage to the primary ACL stabilizer. Examination of 151 ACL ruptures revealed a Ségond fracture in 9% of patients. Nearly all were caused by sports injuries and, understandably, the accident mechanism always included knee flexion and internal rotation of the tibial. In a similarly large number of other knee injuries without damage to the ACL, only one case of a Ségond fracture was found. This phenomenon, which is easy to detect by radiograph, can thus be regarded as a strong indication of the presence of a ligament injury.

[Spontaneous osteonecrosis of the iliac crest. Description of a formerly unverified location]

In a 27-years old male a radiographically well defined and compact area with some lucent sections was found incidentally at the top of the left iliac crest. The resection and the following histomorphologic examination of this tissue brought the diagnosis: spontaneous osteonecrosis of the iliac crest. To our knowledge this is the first time that the iliac crest has been proved as a localisation of the spontaneous osteonecrosis by histomorphologic examination.

Vacuolar/lysosomal proteolysis: proteases, substrates, mechanisms

Proteolysis is an essential post-transcriptional process. The lysosome/vacuole is the central organelle for non-specific proteolysis in eukaryotes. Most proteases that work in the lysosome enter it via the secretory pathway. The bulk of proteins to be degraded enter this proteolytic compartment via endocytosis and autophagocytosis. Our understanding of the mechanisms involved in these processes has increased considerably, and the information obtained in these studies has enabled new, specific proteolytic pathways to be investigated in other cellular compartments, particularly in the cytoplasm.

Biogenesis of the yeast vacuole (lysosome). Signal sequence deletion of the vacuolar aspartic proteinase yscA does not block maturation of vacuolar proteinases

The activation process of vacuolar (lysosomal) proteinases in the yeast Saccharomyces cerevisiae is initiated by the PRA1 (PEP4) gene product, proteinase yscA. To elucidate the importance of the different domains of proteinase yscA in a first attempt the signal sequence of the enzyme was deleted using site-directed mutagenesis. Proteinase yscA delta S underwent processing to an active enzyme, although the amount of mature enzyme was considerably reduced as compared to wild type. Isolation of vacuoles of the mutant strain showed mature-sized proteinase yscA in this organelle. Pro-proteinase yscB is converted to 5-10% to the mature enzyme, whereas procarboxypeptidase yscY is matured, although with reduced kinetics. Thus, the signal sequence of proteinase yscA is not essential for delivery to the vacuole and the activation of a certain amount of the yeast vacuolar proteolytic capacity.

Biogenesis of the yeast vacuole (lysosome). Active site mutation in the vacuolar aspartate proteinase yscA blocks maturation of vacuolar proteinases

The activation process of vacuolar (lysosomal) proteinases in the yeast Saccharomyces cerevisiae is initiated by the PRA1 (PEP4) gene product, proteinase yscA. To elucidate the activation process of proteinase yscA the catalytically active amino acid Asp294 of the enzyme was exchanged with Ala294 using site directed mutagenesis. The resulting proteinase yscA-Ala294 showed no proteolytic activity against the substrate hemoglobin. The mutant protein did not undergo processing in vivo. This phenomenon is in good agreement with the hypothesis that maturation of proteinase yscA is due to self-processing of pro-proteinase yscA. Furthermore, proteinase yscA-Ala294 is not able to convert the zymogens pro-proteinase yscB and pro-carboxypeptidase yscY to the mature enzymes.

[The effect of metamizole on gastric emptying and small intestine transit in the rat]

The effect of the pyrazolone derivative metamizole on the motility of the upper gastrointestinal tract of the rat was investigated. An animal model for simultaneous quantification of gastric emptying and small intestinal transport was used. A test meal with different radioactive labels was administered by means of previously implanted tubes both to the stomach (1.0 ml; 51Cr) and to the duodenum (0.25 ml; 99mTc), and the spatial distribution of both isotopes in a gastrointestinal preparation was determined after a transport time of 30 min. It has been shown that intravenously administered metamizole reduces significantly the percentage of the test meal discharged by the stomach (control: 70.9 +/- 2.8; 50 mg/kg metamizole: 26.3 +/- 6.9, p less than 0.001; 250 mg/kg metamizole: 3.8 +/- 1.5, p less than 0.001); 1250 mg/kg metamizole: 1.1 +/- 0.3; p less than 0.001). The 50- and 250-mg/kg doses had no negative effect on the propulsion of the small intestine. A dose of 1250 mg/kg induced a significant reduction in small intestinal transport (p less than 0.001).

[Behavior of glucosephosphate isomerase in children with malignant diseases]

The normal range of glucose-phosphate-isomerase (GPI) in the plasma of children during the first month of life is up to 80 U/l; until the end of the second year of life between 11 and 50 U/l; thereafter the upper limit is 46 U/l. In osteogenic sarcoma or medulloblastoma there is a good correlation between activity of GPI in plasma and clinical tumor stage. In a lot of other tumors sensitivity of this enzyme is either very low as in Ewing-sarcoma or myeloic leukemia or there is no consistent relation to the extent of the tumor. High activities of GPI are equally obtained in children suffering from cystic fibrosis, diabetes mellitus or muscular dystrophy. GPI is not valid as a tumor marker even being raised in sarcoma and medulloblastoma as mentioned. So it is not necessary to check GPI activity as a part of routine enzyme chemistry.

Unusual electromyographic findings in a patient with polymyalgia rheumatica

A case of polymyalgia rheumatica (PMR) with biopsy-proven giant cell arteritis (GCA) is described in which there were marked abnormalities noted on electromyography (EMG). Spike potentials, positive waves, and fibrillation potentials were seen in the proximal musculature of the upper and lower extremities as well as in the erector spinae muscles. Investigation failed to reveal abnormalities in either creatinine phosphokinase (CPK), aldolase, or muscle obtained at biopsy. The presence of these EMG findings in the PMR-GCA syndrome is unusual. Response to therapy with systemic corticosteroids and normalization of the EMG are documented.