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N F Friederich

Publications and source records attributed to N F Friederich.

At least 19 recordsLinked to original sources
PubMed2006

Multicenter-study of operative treatment of intraligamentous tears of the anterior cruciate ligament in children and adolescents: comparison of four different techniques.

Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5 years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone-patella-bone autografts, 12 patients with quadriceps grafts and 12 patients with facia lata. The mean follow-up was 32 months. Postoperative evaluation included radiographs, KT-1000/2000 stability measurements, Lysholm score, The Tegner activity scale and IKDC score. Neither leg length discrepancy nor angular deformities were noted. Mean KT-1000 difference was 2.1 mm, mean postoperative Lysholm knee score 93.3, IKDC 87% normal or nearly normal. The Tegner index decreased from 6.6 to 5.7. In total, six patients developed instability due to an adequate trauma 1 year after the index operation. Two patients showed mild arthrotic changes. All but two patients were able to return to the same level of preoperative sports participation. None of the four methods studied showed major differences in outcome compared to the other. No growth disturbance could be noted.

Adolescent↗
PubMed2004

[Analysis of wavelet transformed electromyographic signals that were altered by wearing a knee brace].

The comparison of electromyograms represents a challenge for data analysis. The aim of the project was to present a method that uses a minimal computational effort to resolve small but significant changes in the muscular activity that occur while walking with and without a knee brace. The wavelet transformed electromyograms were represented as intensity patterns that resolve the power of the signal in time and frequency. The intensity pattern of each electromyogram defines single points in a pattern space. The distance between these points in pattern space were used to detect and show the separation between the groups of electromyograms that were recorded while walking with and without a knee brace. The method proposes a distance versus angle representation to visually discriminate the intensity patterns. Once it has been shown that the differences are statistically significant, one can visualize the result in a difference intensity pattern that indicates at what time and at what frequency the electromyograms vary between the two conditions tested. It is to be expected that interventions that are more intrusive than a knee brace will reveal even more distinct differences.

Adult↗
PubMed2002

[Bore canal site in surgical reconstruction of the anterior cruciate ligament. Position--placement errors--anatomic measurement].

The goal of surgical reconstruction of the anterior cruciate ligament (ACL) is restoration of its function as closely as possible to a physiological roll-and-glide mechanism. Clinical success means knee joint stability, physiological joint biomechanics, and full range of motion. Anatomical placement of the graft insertion points and anatomical direction of the drilled tunnels are necessary to obtain isometric (anatometric) conditions. Despite technical advances in (arthroscopic) surgery, it is not yet possible to obtain absolute "isometricity" for ACL grafts. However a "physiological" or "relative" isometricity seems to be sufficient for successful clinical results. In 1986 Werner Müller proposed the term "anatometrics" in ACL reconstruction to describe this graft behavior and function. The knee joint is a complex motion system including many active and passive stabilizing elements (ligaments, tendons, muscles) as well as a proprioceptive function of the central column ligaments. Reconstruction of this "system" required the surgeon to have good surgical skills and a well-based knowledge of knee anatomy and function. Wrong placement of insertion points and bone tunnels carry the risk for ensuing graft insufficiency and resultant joint instability. The knee "prefers" a destroyed graft over an overconstrained biomechanical situation! Intraoperative factors for failure may be technical mistakes and intraoperative measuring devices for isometry, which might not guarantee true relations in a ligamentous deficient knee. Therefore, visualization of insertion points (and drilling) under direct arthroscopic view is still preferred over generalized rules and distances as proposed by many commercially available rulers and tapers. Recently, navigation and computer-assisted placement techniques have been developed. The clinical standards of those techniques are still under investigation. At our institution, an arthroscopic approach (visualization, palpation) for ACL reconstruction with a bone-patellar-tendon-bone graft technique is used.

Anterior Cruciate Ligament↗
PubMed2000

Improperly placed anterior cruciate ligament grafts: correlation between radiological parameters and clinical results.

Despite increasing knowledge on knee biomechanics and refined operative techniques, an increasing number of patients are being seen with failed anterior cruciate ligament (ACL) reconstruction. Failure of the reconstruction and further damage to the knee are correlated with improper placement of the graft, which interferes with graft biology and biomechanical demands. Between 1994 and 1995, 63 patients with improperly placed ACL grafts were referred to our institution because of persistent knee instability and pain. A method for analysis of the femoral drill hole on radiography was developed. Before reoperation the radiograph was evaluated by our method, noting the clinical aspects according to the recommendations of the International Knee Documentation Committee (IKDC). The femoral placement of the ACL graft could easily be defined on the lateral and anteroposterior tunnel radiography. The most common error was a femoral placement anterior to the anatomical insertion of the ACL. A significant correlation (P < 0.05) was found between femoral placement of the graft in the sagittal plane and clinical results: the IKDC score declined with increasing distance of the graft from the most isometric bundle of the ACL in the anteroposterior direction.

Activities of Daily Living↗
PubMed2000

Operative treatment of combined anterior and posterior cruciate ligament injuries in complex knee trauma: can the cruciate ligaments be preserved?

A retrospective study was performed focusing on operative treatment after combined anterior cruciate ligament (ACL)/posterior cruciate ligament (PCL) injuries. The operative treatment included the preservation of one or both cruciate ligaments. Twenty-eight patients, average age 30 years (range: 12-55 years), were evaluated 5.4 years (range: 1-14 years) postoperatively. Twenty-two operations were performed in patients with acute injuries (<30 days after trauma) and 6 operations in patients with chronic instabilities (>30 days after trauma). Both cruciate ligaments were preserved by suture or refixation in 16 patients. Suture of one and reconstruction of the other cruciate ligament with autologous tendon graft was performed in 12 cases. In addition, 61 procedures (meniscal suture/resection, medial/lateral reconstruction, tendon suture, and open reduction and internal fixation were performed. Postoperative treatment included continuous passive motion and protected weight bearing. Eleven (27% acute, 83% chronic) patients required revision (ACL/PCL reconstruction, osteotomy, and meniscal repair). At follow-up, 43% of the patients were very satisfied and 46% were satisfied. Seventy-one percent (89% preinjury) of the patients were able to maintain intensive and moderate International Knee Documentation Committee (IKDC) activity levels. The IKDC evaluation of the patients (acute %/chronic cases %) was graded for symptoms: A 39% (45/17), B 35% (27/67), C 15% (18/0), and D 11% (9/17); for range of motion: A 42% (36/67), B 42% (50/17), C 16% (14/17), and D 0%; and for ligaments: A 21% (18/17), B 33% (45/0), C 42% (32/83), and D 4% (5/0). Radiographic findings were A 18%, B 41%, and C 41%. Primary repair of acute injuries was superior to the delayed repair of chronic instabilities. Preservation of cruciate ligaments in acute combined ACL/PCL tears results in a satisfying knee function despite distinct residual ligament instability. Although suture of the cruciate ligaments in open technique is a therapeutic option in acute multiligamentous knee injuries, it is not recommended for the treatment of chronic instabilities.

Adult↗
PubMed1999

[To brace or not to brace? How effective are knee braces in rehabilitation?].

Since the clinical benefit of knee braces has yet to be defined, discussion about braces after reconstructive surgery of the anterior cruciate ligament remains controversial. The use of prophylactic braces in sport did not prove to be effective. In ACL insufficient knee joints, the operative treatment is preferred over the use of functional knee braces. Therefore, the postoperative rehabilitation presents the main application of braces. Modern operative techniques with an initial strong fixation of the ACL graft make a functional postoperative treatment without external fixation possible. In the presented meta-analysis of the literature about knee braces, results from clinical and experimental studies are compared. No published clinical data have shown that braces have any effect on postoperative outcome after ACL-reconstruction. Also, no evidence of a significant bracing effect could be demonstrated in the experimental in vivo or in vitro studies, except a limited stabilizing function for lower shear stress below the physiological loads. Consequently, the systematic use of braces in the rehabilitation after ACL reconstruction cannot be recommended.

Anterior Cruciate Ligament↗
PubMed1999

Tibial and pretibial cyst formation after anterior cruciate ligament reconstruction with bioabsorbable interference screw fixation.

We report a case of an osteolytic tibial enlargement in association with a pretibial cyst formation 8 months after successful anterior cruciate ligament reconstruction with autologous bone-patellar tendon-bone graft and tibial graft fixation with a bioabsorbable interference screw. No joint inflammatory reaction or graft insufficiency was detected. The patient underwent cyst excision and curettage of the tibial tunnel with full recovery and return to preinjury level of activity 2 months after the revision surgery. To our knowledge, the reported complication is the first obvious adverse reaction to a poly-D,L-lactide interference screw in anterior cruciate ligament surgery.

Absorbable Implants↗
PubMed1998

[Pedestrian accidents].

The epidemiology of non-traffic-related, pedestrian injuries in the winter sports resort of Arosa (Switzerland) between 1968 and 1995 (beginning december to end april) was studied. A total of 2813 patients (1140 male and 1673 female patients) with 3010 injuries was surveyed in a general practice. The study showed in the examined period not only an increasing number of injuries and a culmination in February, but also a higher risk for females (60 versus 40 per cent) and an increasing incidence with age. 6% of all patients had more than one injury and 5% required hospitalization. Most pedestrians had injuries of the upper and lower extremity; fracture of the distal radius was the most often diagnosed injury, followed by distortions of the foot and wrist and fractures of the ankle. For accident prevention it is important, that the authorities do not abstain from mechanical cleaning of walking surfaces as soon as they become slippery and from giving out warnings via the mass media. For outdoor walking we postulate boots for ankle protection. The results are discussed and compared with already existing publications.

Accidents, Traffic↗
PubMed1998

Anterior cruciate ligament graft tensioning versus knee stability.

Positioning of the graft for anterior cruciate ligament (ACL) reconstruction and securing the graft at various degrees of knee flexion are interrelated factors when attempting to restore a knee's normal kinematics. The interrelationships between graft positioning on the femur and tibia (graft 'isometricity'); securing the graft at various positions of knee flexion; and the resulting restoration or disruption of the knee kinematics were studied on ten fresh frozen cadaveric knee specimens. Well placed ('isometric') grafts appeared to restore almost normal knee kinematics regardless of the position of the knee at the time of securing the grafts. This was, however, not the case in non-ideally placed grafts. 'Nonisometric' ACL substitutes which became taut in extension, overconstrained the knee if the graft was secured in flexion. If the same graft was secured in extension, increased joint laxity in flexion occurred. In contrast, 'nonisometric' ACL substitutes which became taut in flexion overconstrained the knee if the graft was secured in extension. If the same graft was secured in flexion, the graft became slack during extension.

Anterior Cruciate Ligament↗
PubMed1998

Lengthening osteotomy of the fibula for post-traumatic malunion. Indications, technique and results.

Relative shortening of the fibula may occur after any type of ankle fracture when the lateral malleolus is involved. Patients complain of pain and restriction of their daily and sporting activities. Clinically, there is valgus of the hind foot due to abduction and lateral rotation of the talus. The goal of treatment is to restore the initial length of the fibula by a horizontal or Z-osteotomy, which will also correct the malposition of the talus. This study shows that the operative reconstruction of a widened mortise is a relatively safe procedure, independent of the type of osteotomy used. Lengthening of the fibula is an important step in the treatment of the painful ankle when the fibula is short after trauma, even when degenerative changes of the joint are already present.

Adult↗
PubMed1998

Discoid lateral meniscus in children. Long-term follow-up after total meniscectomy.

We retrospectively reviewed the long-term results of total meniscectomy performed in seventeen knees (fourteen children) to treat a discoid lateral meniscus. The mean duration of follow-up was 19.8 years (range, 12.5 to 26.0 years). On the basis of the rating system of the International Knee Documentation Committee, seven knees were normal (grade A), six were nearly normal (grade B), three were abnormal (grade C), and one was severely abnormal (grade D) at the latest follow-up evaluation. Ten of the seventeen knees had clinical symptoms of osteoarthrosis. Radiographs were available for fifteen of the knees at the latest follow-up evaluation. Eleven of the treated knees could be compared with the uninvolved, contralateral knee. Ten knees had osteoarthrotic changes, such as flattening of the lateral femoral condyle, formation of a ridge along the lateral femoral condyle, and spurring and sclerosis of the tibial plateau. Osteochondritis dissecans developed in two knees, nine and twenty years after the initial meniscectomy.

Adolescent↗
PubMed1998

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Arthroplasty, Replacement, Hip↗
PubMed1998

[Patellar substitution in total knee prosthesis--is it important?].

As shown in long term follow-up studies of Total Knee Arthroplasty (TKA), the femoropatellar joint is an important problem. We report our experience over the past seven years not having resurfaced the patella at the primary TKA at all. Between 1990 and 1997 more than 700 consecutive TKA with the De Puy New Jersey LCS prosthesis were performed. A standardised lateral approach with osteotomy of the tibial tuberosity was used. The patella was redressed, either denervated or left untouched. In no case a primary patellar resurfacing was performed. X-rays of the patello-femoral joint showed a remodelling of the patella over the years, nicely matching the condylar design of the femoral prosthesis. Using a blood-supply-preserving approach and a biomechanically adequate implant, TKA without patellar replacement gives excellent long-term results.

Arthroplasty, Replacement, Knee↗
PubMed1997

[Injury of the dens axis in early childhood. Clinical case report and discussion].

Because of the special features of the subdental synchondrosis, fractures of the odontoid process in childhood can be seen as a separate entity. The subdental synchondrosis must be regarded as sort of an intervertebral disc and not as a growth plate. Among the generally rare fractures of the cervical spine in children this type ist the most common. Usually conservative treatment with a cast-fixation like the halo fixateur or the minerva jacket leads to consolidation. We report on the case of a 2-year-old girl with a fracture of the odontoid process who developed a unilateral syndrome hours after the accident. The treatment was conservative with a halo-like cast fixation. Nine weeks after the fixation bony consolidation was achieved and the cast could be removed. In the first days after fixation full neurological recovery had occurred. In early childhood (till the 7th year of life) according to the literature, patterns of neurologic dysfunction are incomplete injuries of the spinal cord and have the potential for recovery [4, 5, 7, 9, 10, 12].

Child, Preschool↗
PubMed1997

[Coincidence of bone infarct and aggressive bone metastasis].

A 42-year-old male patient presented with a history of persistent pain in the right femur without trauma of 2 months, duration and an episode of bloody stools 3 months earlier with no clinical findings upon examination. X-rays and CT scan revealed a circumscribed lesion with sclerosis and periostal reaction in the right proximal femur. A three-phase bone scan showed a massive hot spot in this area. Primarily differential diagnoses included a Brodie's abscess and/or a tumor. An excisional biopsy of the area was performed and revealed the coexistence of a bone infraction and the metastasis of an adenocarcinoma of unknown origin. The lesion in the bone was resected, filled with autogenous cancellous bone and stabilized with a plate. Further intensive screening with CT of the abdomen, gastroscopy and colonoscopy led to the primary tumor, an adenocarcinoma at the rectosigmoidal junction. No other metastases were detected. This patient presented with severe pain an radiologically divergent findings: a presumably benign process on radiography, but a massive hot spot on scintigraphy. Further procedures such as a CT scan and/or MRI had to be undertaken. If the analysis includes the differential diagnosis of a malignant process, a biopsy must be obtained, and if this reveals a metastasis, the primary tumor must be sought.

Adenocarcinoma↗
PubMed1996

[Shoulder problems in leisure athletes: physical examination, diagnosis and therapy. Sensible procedures in daily practice].

At first sight the anatomy of the shoulder may seem simple (see Fig. 1). However, for the physician treating a patient suffering from shoulder pain, the scapulo-thoracal interplay of 5 joints and 19 muscles, providing a wide and varied range of motion, may constitute an obstacle difficult to overcome. In the leisure athlete acute injuries must be distinguished from degenerative disease. Contact sports in particular tend to involve risks of falling on the shoulder, injuring the shoulder girdle or the elbow and wrist, sometimes with major consequences: complex fractures, dislocations, ligament and tendon lesions or joint instabilities. Thorough, rapid and cost-effective diagnostic evaluation of the athlete, involving clinical examination (function tests), radiographic imaging (shoulder a.p., y-view) and in selected cases ultrasonography (compared with the other side) may be necessary in starting early and effective therapy.

Acromioclavicular Joint↗