[Current technologies in orthopedics].
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Humans↗
Biomedical subjects
C J Wirth
Publications and source records attributed to C J Wirth.
[Historical development of muscle replacement operations in brachial paralysis].
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Brachial Plexus↗
Medial meniscus replacement by a fat pad autograft. An experimental study in sheep.
The medial meniscus in 15 sheep was replaced by a pediculated infrapatellar fat pad graft and resulted in the development of a macroscopically meniscus-like structure within 6 months. Five additional sheep with a meniscectomy were controls. Degenerative changes in the fat pad autograft were visible after one year. Osteoarthritis of the weightbearing medial compartment was detected after 6 months. A temporary protective effect on the cartilage could be attributed to the autograft, but the long term results indicated that this was not permanent. Fat is not suitable as a meniscal substitute.
Adipose Tissue↗
Reconstruction of the lateral ligaments of the ankle using a regional periosteal flap.
We have treated 94 patients with chronic instability of the lateral side of the ankle by reconstruction of the ligaments with local periosteal tissue. We reviewed 90 cases after a mean follow-up of 2.8 years (2 to 9) using a questionnaire, clinical examination and radiography. The results on a 100-point ankle score indicated that 81% had a good or excellent result. The periosteal flap-replacement technique allows anatomical reconstruction and does not sacrifice other ligaments or tendons in the foot.
Adolescent↗
[Cartilage cell transplantation. Experimental principles and clinical applications].
Transplantation of autologous chondrocytes proliferated in vitro to treat cartilage defects is discussed controversially. Cartilage has only a very limited capacity to regenerate. The repair tissue is of minor biomechanical stability and therefore induces degenerative arthritis of joints in the long term. Facial cartilage defects may lead to aesthetic or functional problems. Different biological and synthetic substitutes were used to treat cartilage defects in orthopaedic and facial plastic surgery. Biological tissue for transplantation is not abundant and synthetic materials may induce foreign body reactions. Amplification of autologous cells in vitro to produce a tissue similar to the impaired tissue seems tempting. It is transplantable into the defect and is tough to restore the defective surface completely. This is the intention of numerous scientific investigations concerning chondrocyte application to cartilage defects. Transplantation of isolated chondrocytes is currently used in clinical trials also. The possibilities and limitations of this technique are discussed including the fundamental principles and our own experimental investigations. A proof for the reproduction of a tissue similar to native cartilage with its typical long term mechanical properties is still missing. Further laboratory and clinical studies should be conducted before the technique is propagated in patient care.
Animals↗
Techniques of cartilage growth enhancement: a review of the literature.
This review attempts to present an overview of the literature pertaining to the techniques of cartilage growth enhancement. Only cartilage has an incomplete capacity for self-repair, especially of superficial defects. Full-thickness defects involving the subchondral bone can be repaired with the use of pluripotent progenitor cells from bone marrow or from transplanted perichondreum or periosteum. Bone-cartilage autografts and allografts transplanted into the cartilage defect heal primarily, but they loose their long-term biomechanical qualities because of transformation into fibrous cartilage. Cultivated human chondrocyte autografts may make cartilage healing possible in the future.
Animals↗
Revision anterior cruciate ligament surgery: experience from Germany.
From 1976 to 1992, reconstruction after failed anterior cruciate ligament repair or reconstruction was done for 87 patients (8%) compared with 1064 primary operations at the authors' institution. Fifty-seven patients had 1 previous reconstruction, 27 patients had 2, and 3 patients had 3 or more previous reconstructions. Fifty-two patients (60%) were satisfied with their results after a mean followup time of 8 years (range, 2-18 years). Lysholm scores after revisions (68 +/- 12) were significantly inferior compared with scores after primary anterior cruciate ligament surgery (83 +/- 14). The authors favor the use of the patellar tendon or quadriceps tendon autograft in revision surgery. Medial meniscus reconstruction is done whenever possible, or the medial meniscus is replaced by autograft tissue. Open or arthroscopic techniques are used, depending on the individual case.
Adolescent↗
[Significance of arthrodeses].
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Arthrodesis↗
[Maintaining tradition by supplementing the new].
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Education, Medical, Continuing↗
Frozen shoulder--treatment and results.
Even today the aetiology of the frozen shoulder is still under discussion. At the Orthopaedic Department of the Medizinische Hochschule Hannover, 118 persons with a frozen shoulder were treated as in- or outpatients between 1980 and 1988. We investigated the results of two different specific therapy concepts. Most of the patients received a mixture of drug therapy and physical rehabilitation under the guidance of a physiotherapist. In a smaller group of patients, the frozen shoulder was mobilized under anaesthesia (mobilisation force). After an average follow-up time of 3.8 years from the start of treatment, 93% of the patients was examined by means of an individual subjective rating (score). In addition, a clinical examination was performed in 69% of the cases. According to the subjective personal rating (score) as well as the improvement in range of motion, moderate mobilisation led to better results than the mobilisation under anaesthesia.
Adult↗
A dynamic shoulder model: reliability testing and muscle force study.
This study introduces a dynamic shoulder model, where forces were applied to individual muscles in ten cadaveric specimens. The model provided reproducible glenohumeral joint motion and thereby allowed the investigation of active, glenohumeral joint mechanics. Forces were created by servo-actuated hydrodynamic cylinders and applied to the deltoid muscle and to the rotator cuff through wire cables. Computerized regulation initiated precise, time controlled cycles of glenohumeral joint motion. The position of the glenohumeral joint in all spatial orientations was measured and recorded using an ultrasonic sensor device. Reproducibility of glenohumeral joint motion was demonstrated on the basis of five cycles of glenohumeral joint elevation. Repeatability variance of position measurements for five cycles of elevation averaged 0.80 degrees for abduction, 0.75 degrees for anteflexion and 1.36 degrees for internal rotation. Arm weight and force distribution at the shoulder musculature were estimated according to the literature. In comparison to estimated physiologic conditions, a one third increase of arm weight led to a significant (p < 0.05) decrease of elevation of 20%, a one third decrease of arm weight to an average increase of elevation of 18% (p < 0.05). Exclusion of the supraspinatus muscle caused a significant (p < 0.05) 6% decrease of elevation of the glenohumeral joint. Without force applied to the subscapularis and infraspinatus/teres minor muscles, elevation decreased 16% (p < 0.05). A decrease of glenohumeral joint elevation of 25% resulted when force was applied to the deltoid muscle alone (p < 0.05).
Adult↗
Function of the supraspinatus muscle. Abduction of the humerus studied in cadavers.
We evaluated the function of the supraspinatus tendon with a dynamic shoulder model. Active glenohumeral joint motion was simulated in 10 cadaveric shoulder specimens with hydrodynamic cylinder forces at the deltoid muscle and at the rotator cuff. Computerized regulation initiated standardized cycles of glenohumeral joint motion, where the isolated effect of the supraspinatus muscle could be studied. The efficacy of the supraspinatus muscle on elevation of the glenohumeral joint was measured with an ultrasonic sensor system. Pressures underneath the coracoacromial vault were recorded with capacitive sensors, as an indicator of the impingement at the shoulder. Elimination of force of the supraspinatus muscle led to a 6 percent decrease in elevation of the glenohumeral joint. The deltoid muscle was able to reverse this loss of elevation by a force increase of one third of the lost supraspinatus force. If no force was applied to the supraspinatus muscle, average pressures underneath the coracoacromial vault decreased 8 percent. It was concluded that the supraspinatus produces less torque and more glenohumeral joint compression than the deltoid. However, the supraspinatus has no effect on depression of the humeral head during elevation. The clinical consequence of our observations is that operative closure of supraspinatus tendon defects is not mandatory.
Adult↗
[Transplantation of allogeneic menisci].
The increase in severe ligament injuries of the knee has led to consideration of the need for meniscal transplantation in reconstructive operations for chronic rotational instability. Transplantation of the medial meniscus was carried out in 30 sheep, which were divided up into 2 groups, each containing 15 sheep. In the first group lyophilized, y-sterilized allogeneic menisci were transplanted and these underwent complete remodelling in 48 weeks. In the other group, deep-frozen allogeneic menisci were used and these remained fully functional without remodelling. Twenty-three transplantations of the medial meniscus combined with replacement of the anterior cruciate ligament were performed from May 1984 to December 1986. Clinical follow-ups were coupled with arthroscopic follow-ups on an average of 10 months post-operatively in 19 sheep. In 17 cases a lyophilized meniscus was transplanted and in 6 cases a deep-frozen allogenous meniscus was used. There were no operation-specific complications in either group. Both the lyophilized meniscus transplants and the deep-frozen ones underwent a reduction in size during the observation period. Good-to-excellent results were generally obtained with the deep-frozen transplants; however, there is the risk of transmitting disease. The results seen in the lyophilized transplants were less satisfactory due to a reduction in size, sometimes down to the regeneration size. Taking the infrapatellar fatty pad for meniscal replacement (as suggested by Lexer), we saw only weak meniscus-like tissue after the first year postoperatively. The meniscus tendon by means of an autologous tendon for meniscus replacement may be an alternative procedure. Therefore, allogeneic meniscus transplantation for reconstruction of the knee joint cannot be recommended at present as a standard procedure.
Adult↗
[Revision surgery after failed anterior cruciate ligament repair].
Not every reconstruction of the anterior cruciate ligament is successful. Possible reasons for failure are renewed severe trauma, inadequate fixation of the transplant, an isometric mistake, weak transplant material, an anterior cruciate ligament reconstruction performed in isolation in a complex unstable knee, or prosthetic ligaments. Revision surgery is indicated when patients complain about the recurrence of knee instability. Preoperative diagnostic procedures must include X-rays with the knee in defined positions in order to determine drill hole courses and visualize any signs of arthrosis and the patellar position. Revision surgery is hampered by disadvantageously placed drill holes, exhaustion of the supply of transplant material, secondary instabilities, gonarthrosis or a possible arthrofibrosis. During rehabilitation a variable knee position is imperative, because of the different procedures that might need to be implemented.
Anterior Cruciate Ligament↗
[Stress reactions and stress fractures in the high performance athlete. Causes, diagnosis and therapy].
From 1987 until July 1991 70 athletes with stress reactions or stress fractures were treated in the orthopaedic department of the Hannover Medical School. The average age of the 42 male and 28 female athletes was 22.6 years. The number of athletes involved in track and field sports was 29 (41.4%), in gymnastics 9 (12.9%) and in soccer 5 (7.1%). The most common bone injured was the tibia in 29 (41.4%), followed by the tarsal navicular in 21 (30.0%), the midfoot in 17 (24.3%) and the fibula in 4 (5.7%) athletes. In three cases double stress fractures were found in adjacent locations; in one case a stress fracture of the opposite navicular occurred after the initial tarsal navicular stress fracture had healed, and in another case the tarsal navicular was found to be fractured again. Thirty-seven percent of the athletes claimed sudden increase in training intensity was the cause; 33% felt that the increased sprinting and jump activities were the reason for their complaints. In some athletes pain started after an ankle sprain. Standard diagnostic procedure consisted in X-rays in two planes and three-phase bone scanning. In tarsal navicular or tibial locations additional tomograms were performed. MRI and CT scans were reserved for unclear findings and to exclude the possibility of a tumorous or inflammatory process. A new grading system was introduced that covers all forms of stress reactions from periostitis to pseudarthrosis. Clinical symptoms, sport disabilities, radiological and bone scan findings were graded from A to D. Using a modified Wilson classification, all radiologically recognizable stress reactions could be classified.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
A case of stenosing peroneal tendovaginitis.
At the foot and ankle, stenosing peroneal tendovaginitis has only rarely been described in literature. The superior and inferior peroneal retinacula, however, may cause symptoms of stenosis similar to other tendons in the foot and the hand. A case of a forty-three year-old woman is presented, where posttraumatic stenosing peroneal tendovaginitis caused sudden pain on supination of the foot. Nodular tendon swelling was present on a preoperative CT-scan. The condition was treated successfully by transsection of the peroneal retinacula.
Adult↗