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Biomedical subjects

R P Jakob

Publications and source records attributed to R P Jakob.

At least 19 recordsLinked to original sources
PubMed1998

Anterior cruciate ligament graft positioning, tensioning and twisting.

This paper reports on a scientific workshop to study anterior cruciate ligament (ACL) reconstruction. The aim is to present recommendations for ACL reconstruction methods that will be of use for surgeons. A study of knee anatomy and graft placement concluded that the tibial attachment must be posterior enough to avoid graft impingement against the femur, and methods to attain this were presented. On the femur, poor graft placement leads to excessive changes of the graft attachment site separation distance as the knee flexes, and the worst case corresponds to the attachment being too far anterior. It was agreed that there were typical patterns of graft tension changes as the knee flexes, and that grafts should be tensioned close to full knee extension. A typical tensioning protocol would be 60 N tension applied at 10 degrees of flexion. It was recognised that graft remodelling caused uncontrollable tension changes post-operation. Graft twisting, to recreate the anatomical spiral of ACL fibres seen in the flexed knee, was also discussed.

Anterior Cruciate Ligament↗
PubMed1997

Sequential intramedullary nailing of open tibial shaft fractures after external fixation.

We reviewed 32 tibial shaft fractures in 31 patients treated with sequential intramedullary nailing after primary external fixation. There were 30 open fractures and 2 closed injuries with severe blunt trauma requiring fasciotomy. Fifty per cent of the fractures were classified as Gustilo type III A and B injuries. The mean external fixation treatment averaged 6.6 weeks, and secondary intramedullary nailing was done on average 7.4 weeks after injury. In 50% of the fractures, secondary nailing was done at the same procedure as removal of the external fixation. Overall, the incidence of osteomyelitis and non-union was 3.1% each and of malunion 19%. The time to full weight-bearing averaged 31.2 weeks. The results were separately analyzed according to Gustilo types and subtypes. In the Gustilo type III B injuries, the incidence of osteomyelitis and non-union was 11%, while malunion occurred in 33%. The time to full weight-bearing averaged 53 weeks. These results support the conclusion that this treatment modality is a valid alternative to other treatment options. However, previous pintract infections should be regarded as a contraindication for secondary nailing.

Adolescent↗
PubMed1996

High tibial osteotomy alone or combined with ligament reconstruction in anterior cruciate ligament-deficient knees.

UNLABELLED: High tibial osteotomy (HTO) is widely accepted as a treatment option in patients with medial unicompartimental osteoarthritis (OA) and varus morphotype of the knee. We increasingly see younger patients with a chronic anterior instability, an additional varus morphotype and beginning medial OA. Treatment options for these patients are not clear up to now. In this clinical study we compare for the first time three different treatment rationales and introduce a concept of symptom-oriented surgery in young patients with medial OA and chronic anterior instability. MATERIALS/METHODS: Between 1984 and 1994 30 patients were treated with a medical unicompartimental OA and chronic anterior instability of the knee. Patients were grouped into three different groups according to treatment. 1) only HTO was performed. 2) HTO and simultaneously an ACL-reconstruction and 3) HTO and 6-12 months later an ACL-reconstruction was performed. 27/30 patients were available for follow-up. All patients had an arthroscopy before surgery. Evaluation was done according to the IKDC-protocol and X-ray documentation. RESULTS: Pain was a major problem in all patients. None of them was completely pain-free. 8/27 patients had pain even with light activities. This included 1/11 patients of group 1, 3/8 of group 2 and 4/8 of group 3. 9/27 patients had stable knee joints with a Lachman-test of 3-5 mm. No patient had a Lachman test < 3 mm. 3/11 patients of group 1, 3/8 of group 2 and 2/8 of group 3 had a Lachman test of 5-10 mm. A positive pivot-shift could be found in 9/27 patients. 2/11 of group 1, 4/8 in group 2 and 3/8 in group 3. The overall IKDC-score improved in 23/27 patients, one patient remained unchanged, two deteriorated. Radiologically a slight progression of OA could be seen in all patients. Radiological signs of OA and pain did not show any correlation. There was, however, a significant rate of postoperative complications involving 4/11 patients of group 1 and 3/8 of group 3. There were 6 major complications in 5/8 patients in group 2. Nevertheless overall patient satisfaction was high. 25/27 patients would undergo the procedure again. CONCLUSION: HTO is a good treatment option for younger patients with medial OA and chronic anterior instability of the knee. These patients pose a high challenge to diagnostic and operative skills of the surgeon. Main symptoms of these patients have to be analysed clearly in terms of instability and pain. In patients aged 40 and older an HTO alone is an excellent treatment option with reproducibly good results. In younger patients we advise an HTO first. If instability persists, an ACL-reconstruction can be done 6-12 months later. One has to be aware that a simultaneous combined procedure has a significant complication rate. Hence if a simultaneous combined treatment is planned the surroundings including surgical technique, rehabilitation and patient compliance have to be ideal. These young patients need an activity counselling in order to realise that their knee joint has suffered significantly from the injury and ongoing high physical demands on their knee joint.

Adult↗
PubMed1996

[Orthopedic examination techniques of the knee joint--basis for diagnosis and indications].

The work up of indication is the aim of each thorough examination. Using the example of the knee joint, we subdivide into five group of diagnosis: anterior knee pain (femoropatellar syndrome), intraarticular derangement, osteoarthritis, infectious and rheumatoid arthritis, forms of bursitis and tendinitis. Clinical signs, diagnosis and natural history are listed, which present the basis of indication.

Arthritis, Infectious↗
PubMed1996

[Shaving of the cartilage: how much is healthy?].

The shaving of the knee joint can only help patients, who suffer from gonarthrosis, if the tissue, whether it is a mechanical part of hindering cartilage or a part of meniscus, is removed parsimoniously. An improvement is reached through the removal of the mechanical obstacles and also through a washing of the joint and lessening of the painful articular irritation. A cartilage that has been treated by a superficial shaving is not able to regenerate. A deeper shaving with a removal of the subchondral bone leads to a partial reconstitution of a substitute cartilage (fibrous cartilage), according to the age of the patient and to the alignment of the knee joint. This regeneration is not necessarily accompanied by a relief of pain. Nevertheless, the substitute cartilage does not attach itself firmly with the near-lying hyaline cartilage. At the same time the fibrous cartilage supports weight with difficulty and degenerates rapidly. The indication of the shaving of the knee joint should only be applied by exception and be reserved for middle-aged patients with a gonarthrosis and with signs of mechanical stocking.

Age Factors↗
PubMed1996

[The value of corrective osteotomies--indications, technique, results].

Corrective osteotomies around the knee joint gained wide acceptance in the treatment of unicompartmental osteoarthritis of the knee joint despite the improvements in total and partial knee arthroplasty. The combination of axial malalignment of the lower limb with degenerative changes of one femorotibial compartment accentuates the stress onto the damaged cartilage with subsequent increase in the magnitude of axial deformity. The reduction of stress can be achieved by realignment of the leg, which in turn redistributes the forces to more normal areas of the joint. The main goals of the osteotomy include relief of pain and improvement of function. Careful patient selection and assessment as well as a precise surgical technique enable the surgeon to more predictive and improved clinical longterm results. The ideal candidate for a corrective osteotomy is in the sixth or seventh decade of life with a clearly localized, activity-related knee pain, axial malalignment of the leg and radiologically unicompartmental degenerative arthritis. Nevertheless, the patient's activity level and his personal expectations after the procedure are worth to be discussed in context with other treatment possibilities. As with prosthetic replacement, the patient has to understand that the surgical procedure will not provide a normal joint: but "buying time" with an osteotomy may be a viable concept.

Aged↗
PubMed1996

[Managed health care--second opinion from the viewpoint of Swiss orthopedists].

Health Care reform rapidly changes the US health system and enters our "free system" with various aspects. The understanding of the buzzwords in managed care and the so-called managed competition are the context for making informed decisions about our future. We must develop at least a rudimentary understanding of the ways many types of collaborative efforts and managed care organisations evolve. We must know to ask the right questions and hopefully find the correct answers for the benefit of our patient.

Cost Control↗
PubMed1995

Use of the ipsilateral vascularised fibula for tibial reconstruction.

Between 1989 and 1994 we used a vascularised ipsilateral fibular graft in 24 patients with segmental tibial defects. We report 12 patients with a minimum follow-up of two years. The graft was either transposed medially or inverted on its vascular pedicle. Full weight-bearing was achieved at between four and seven months. We had few complications and consider that the use of this method is a valuable option in reconstruction of the tibia.

Adult↗
PubMed1994

Avascular necrosis following traumatic hip dislocation in an 8-year-old boy.

Avascular necrosis of the femoral head as a complication of a hip location that is caused by minor trauma and is promptly reduced is uncommon in young children. The incidence appears to be from 3% to 6% if reduction is performed within the first 4 h. However, if it does occur, a significant incidence of degenerative joint disease should be anticipated in the patient's later life. As a possible way of surgical treatment, an intertrochanteric and periacetabular osteotomy should be considered to minimise sequelae. Follow-up must be continued until skeletal maturity is reached.

Child↗
PubMed1994

Positioning of the posterior cruciate ligament.

The isometric position in ligament reconstruction is the one in which there is little or no change in the length of the graft with range of motion of the joint. It varies according to the positions of the tunnels that will become the attachment sites of whatever graft is being used. Better understanding of this concept that greatly improved the surgical results of intra-articular reconstructions of the anterior cruciate ligament. Unfortunately, the results of posterior cruciate ligament (PCL) reconstructions have lagged behind. A better understanding of the isometry of the PCL and how it relates to the positioning of a graft at the time of reconstruction should help improve the situation. The current scientific studies on the PCL as they relate to isometry are evaluated and summarised in this paper. The tibial isometric point was universally less sensitive to changes in position than was the femoral isometric point. However, all the points that were evaluated for the tibia fell within the normal insertion area of the PCL. This has important ramifications when extrapolating these laboratory studies to the operating room, where it is imperative to get the tibial tunnel or attachment site distal enough on the tibia so that it will be in the usual anatomic location of the PCL. There is less uniformity when it comes to the femoral isometric point, but once again the isometric point from each of the studies fell within the normal anatomic femoral attachment site. The differences between the selected points may be explained by the different study designs.

Cadaver↗
PubMed1994

Development of the small AO fixator to the current set.

An indirect system to reduce and hold comminuted fractures of the distal radius was developed in the mid 1970's starting with a simple threaded distraction rod and advancing to a versatile system of rods and universal clamps. This system has gained wide acceptance since then and is used for the wrist joint and for other indications in surgery of the hand, the upper limb, the foot and in paediatric orthopaedics.

Equipment Design↗
PubMed1994

Twelve years follow-up of fractures of the distal radius treated with the AO external fixator.

From 1977 to 1982 a total of 55 patients suffering comminuted fracture of the distal radius were treated with the external fixator. Fifty of these were followed up in 1983/85 and 32 of them were available for assessment in this study (1992). The follow-up period was 11.6 years on average. All patients had suffered an intra-articular fracture (91% a C-fracture, 9% a B-fracture according to the AO classification), 27 patients had also fractured the ulnar styloid process and in 11 a dye-punch fragment was present. Both wrists were assessed on the basis of case history, clinical examination, radiographs in two planes and visual analogue scales (VAS). The results were evaluated using established scoring systems. On the Gartland and Werley scale 75% of the results were good or very good, 63% according to Castaing. In general, there was no statistically significant difference between the results of this study and those of 1983/85. It could be demonstrated that there was a relationship between arthritis as a late complication and the existence of an intra-articular step-off of at least 2 mm at implant removal. This also has a negative influence on the range of motion and strength. Radial shortening affects the functional result whereas a die-punch fragment does not. On VAS patients identified performance restriction and disability as the worst consequences of the accident; these criteria correlated best with the results of objective evaluations. In contrast, patients were more satisfied with the result of treatment than would be expected from the objective analyses. The overall results indicate that exact reduction was extremely important. Long-term follow-up showed that the use of the external fixator in the treatment of comminuted intra-articular fractures of the distal radius was an adequate method. Prospective and possibly multicentric studies would be required to investigate more detailed relationships between treatment and long-term results.

Adult↗
PubMed1994

Three-dimensional dynamic AO external fixation of distal radial fractures--a preliminary report.

External fixation of unstable and intra-articular distal radial fractures has become increasingly popular. Dynamic external fixation, allowing movement of the wrist during the fixation period, is a relatively new approach which may further improve functional end results. To permit early functional treatment, the small AO external fixator was supplemented by a joint allowing all three degrees of rotational freedom. The centre of rotation is located at a point outside the device and lies approximately in the head of the capitate. With the natural centre of wrist rotation coincident with that of the fixator, admissable movements of the wrist include both flexion-extension and radio-ulnar deviation, without threatening fracture reduction. In vitro testing and initial clinical experience with a prototype are encouraging. Several improvements of the original design have been made and a multicentric clinical study is scheduled for further evaluation of the new dynamic external fixator.

Adult↗
PubMed1993

Evaluation of knee ligament injuries with the IKDC form.

Various scoring systems have been proposed to quantify the disability caused by knee ligament injuries and to evaluate the results of treatment. None of these systems has found worldwide acceptance, mainly because all scoring systems attribute numerical values to factors that are not quantifiable, and then the arbitrary scores are added together for parameters not comparable with each other. For these reasons a group of knee surgeons from Europe and America met in 1987 and founded the International Knee Documentation Committee (IKDC). A common terminology and an evaluation form was created. This form is the standard form for all publications on results of treatment of knee ligament injuries. It is a concise one-page form. It includes a documentation section, a qualification section and a evaluation section. For evaluation there are four problem areas (subjective assessment, symptoms, range of motion and ligament examination). These are supplemented with four additional areas that are only documented but not included in the evaluation (compartmental findings, donor site pathology, X-ray findings and functional tests). The form can be used pre- and post-operatively and at follow-up. It has been specified that in any publication the minimum follow-up time for short-term results should be 2 years, for medium-term results 5 years and for long-term results 10 years. The largest part of the sheet is the qualification section. It is called "qualification" section rather than "scoring" section because no scores are given. Each parameter is qualified as "normal", "nearly normal", "abnormal" or "severely abnormal". This qualification is less subjective and emotional than "very good", "good", "fair" and "poor".(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗