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Biomedical subjects

A Lindstrand

Publications and source records attributed to A Lindstrand.

At least 73 records · Page 4Linked to original sources
PubMed1991

Ten-year results of tibial osteotomy for medial gonarthrosis. The influence of overcorrection.

The results in relation to the correction achieved 1 year after surgery of a series of tibial osteotomies in 50 patients (52 knees) are presented with a total observation time of 10 years. Mean age at the time of osteotomy was 56 years. Overcorrected knees had a significantly better result after 10 years. Progress of gonarthrosis occurred in 6/34 overcorrected knees compared with 3/4 in the normo- and undercorrected group. One out of 34 overcorrected knees recurred in varus. Five knees were revised by knee arthroplasty or reosteotomy one of which was overcorrected.

Adult↗
PubMed1991

On the problem of heat generation in bone cutting. Studies on the effects on liquid cooling.

A saw blade was made from two standard oscillating blades which were fixed to each other with channels between, so that cooling fluid could be directed to the saw teeth. The blade was connected to a standard arthroscopy pump which delivered a flow of 80 ml/min through the blade. The performance of this blade was compared with that of a standard saw blade, cutting ox-bone in the laboratory. Irrigation of the standard saw blade with saline delivered by a syringe only slightly diminished the maximum temperature. Pumped irrigation was more effective but required large volumes of fluid. The heat generated by the internally cooled saw blade was negligible and the temperatures achieved (19 degrees C to 34 degrees C) fell well below the critical level for bone death (44 degrees C to 47 degrees C).

Equipment Design↗
PubMed1991

Osteonecrosis of the knee. Diagnosis and outcome in 40 patients.

Clinically suspected primary osteonecrosis of the knee was studied in 40 patients with repeated plain radiography and scintimetry, and the patients were followed for 1-7 years. Thirty-three patients had typical scintimetric and radiographic signs of osteonecrosis of either one of the femoral condyles, whereas 7 patients had only typical scintimetric findings, but never developed an osteonecrosis based on plain radiography. Because the scintimetric findings were identical to the other 33 knees and because there is no other well-known localized disease in this region of the femoral condyle, we deemed that these 7 patients had probable osteonecrosis, but in an abortive form. The scintimetries were prognostic during the second half year after onset. Thirty knees had a poor outcome--29 because of development of arthrosis, of which eight were treated with a knee arthroplasty and four with a proximal osteotomy.

Adult↗
PubMed1991

Proteoglycan epitope in synovial fluid in gonarthrosis. 28 cases of tibial osteotomy studied prospectively for 2 years.

High tibial osteotomy was performed for medial gonarthrosis in 28 patients. Preoperatively, and at 3, 12, and 24 months after surgery, clinical and radiographic examinations were made, and joint-fluid samples were aspirated. Arthroscopy was performed preoperatively and at 24 months. Immunoassay of proteoglycan epitope in joint fluid showed an increase in concentration at all times as compared with a reference population with normal knee joints. An increase in both the concentration and the total amount of proteoglycan epitope in joint fluid was noted at 3 months postoperatively with a return to preoperative values at later times. Regrowth of fibrocartilage did not correlate with proteoglycan epitope data.

Adult↗
PubMed1991

Anterior-cruciate-insufficient knees treated with physiotherapy. A three-year follow-up study of patients with late diagnosis.

To evaluate a functional neuromuscular training program focusing on strength, endurance, postural control, and agility, 26 patients with a rupture of the anterior cruciate ligament (ACL) diagnosed late were examined before starting a training period and then followed for three years. During the study period, four of the patients had an ACL reconstruction. Twenty-two patients treated without surgery were satisfied with the improvement in their knee function and activity level after three to six months of physiotherapy. Compliance with the rehabilitation program was good and the improvement achieved on completion of the training period was maintained for three years in this group of recreational sportsmen and women. Quadriceps strength, functional knee score, activity level, and functional performance were all improved after training and were maintained during the follow-up period.

Adolescent↗
PubMed1991

Prognosis for patients with medial gonarthrosis. A 16-year follow-up study of 189 knees.

All 189 knees (157 patients) that had had primary medial compartment arthrosis in 1972 were followed until 1988. After 14 years, tibial osteotomy had been performed in 85 knees and arthroplasty in 33 knees. No major surgery had been performed in 71 knees; of these 71 knees, 31 patients (40 knees) had died. Of the remaining 23 patients (31 knees), the majority had an unsatisfactory knee and managed only on a low activity level. In 20 of 24 knees, progress of the arthrosis was recorded roentgenographically. Because natural course of medial gonarthrosis has a poor prognosis, the majority of patients suffering from this condition will eventually have major knee surgery.

Activities of Daily Living↗
PubMed1990

Statistical evaluation of the diagnostic criteria for meniscal tears.

The accuracy of diagnosis was tested in a prospective study of 145 patients who were arthroscoped because a meniscal tear was suspected clinically. Multiple variate analysis was used to evaluate 68 different clinical parameters. The clinical accuracy was 61% as a tear was demonstrated in 88 knees; 73 of these tears were associated with other intraarticular abnormalities. Thirteen knees were entirely normal at arthroscopy. It was possible to predict a meniscal tear in 8 out of 10 patients.

Adolescent↗
PubMed1990

Spontaneous osteonecrosis of the knee: value of MR imaging in determining prognosis.

Sixteen patients with early and late stages of spontaneous osteonecrosis of the knee were studied to evaluate if MR imaging can be used to determine the prognosis of the disease. All patients had sequential conventional radiographs and clinical examinations, one or more 99mTc-methylene diphosphonate bone scintigrams, and an MR examination. The duration of the disease at the time of the MR examination ranged from 1 to 58 months (mean, 18 months). A relationship was identified between the pattern of bone marrow alteration noted on long TR/TE MR sequences and the scintigraphic stage and clinical course of the disease. The dimensions of the osteonecrotic region could be identified as well or better on the short TR/TE MR images than on the radiographs in all patients. MR imaging also afforded evaluation of the hyaline cartilage overlying the osteonecrotic lesion, revealing secondary osteoarthrosis in seven patients. We conclude that MR imaging in patients with spontaneous osteonecrosis of the knee may provide information of value for determining the prognosis of the disease.

Adult↗
PubMed1990

Cold flow reduced by metal backing. An in vivo roentgen stereophotogrammetric analysis of unicompartmental tibial components.

Thirty-six cases of unicompartmental arthroplasty for gonarthrosis were followed for 6 years. The arthroplasties were prepared for roentgen stereophotogrammetric analysis (RSA) by marking the tibial components and the tibial methaphysis with tantalum balls. Nineteen out of 24 cases with a polyethylene tibial component had an increase in intermarker distances signifying progressive enlargement of the prosthesis due to cold flow. The enlargement was up to 2.8 percent of the circumference and was greater for 9 mm than for 12 mm thick components. Twelve cases with a metal-backed tibial component showed no cold flow. No correlation between cold flow and demographic, clinical, or radiographic data was found.

Aged↗
PubMed1990

An internally cooled saw blade for bone cuts. Lower temperatures in 30 knee arthroplasties.

A saline-cooled saw, which has been shown to give good control of the heat generation during bone cutting under laboratory conditions, was tested in in vivo. With a saline flow of 80 mL/min, the maximum cutting temperature in 30 knee prosthetic operations was 32 (25-37) degrees C in the saw blade and respectively 30 (26-35) degrees C and 29 (26-34) degrees C 2 and 3 mm underneath the cut surface. Because the temperature generated by conventional osteotomy equipment may exceed 70 degrees C, the use of our cooled double saw blade during joint replacement prevents heat osteonecrosis.

Arthroplasty↗
PubMed1990

Three-phase scintimetry in osteonecrosis of the knee.

Three-phase scintimetry with 99mTc MDP was analyzed in 40 patients with a clinical history of spontaneous onset of knee pain and a focal static isotope uptake in the femoral condyle indicating osteonecrosis. A strong correlation was found between pool-phase ratios and the static ratios. The pool-phase study did not add to the information obtained from the flow phase and static studies. There was a characteristic change of the pattern of the early flow-phase curves with the duration since the onset of symptoms indicating hyperemia early in the disease. A persistent high flow-phase and static-uptake ratio 6-12 months after the onset of symptoms correlated positively with a poor clinical and radiographic outcome. The 10 patients with a good prognosis had, as a group, a more rapid decrease in isotope uptake after 6 months. There was a positive correlation between a high static uptake ratio and the size of the lesion, and subsequently with the clinical and radiographic outcome. 30 patients developed arthrosis and/or severe clinical symptoms. Five of the 10 patients who did not develop arthrosis never developed radiographic evidence of osteonecrosis.

Adult↗
PubMed1990

Revision after osteotomy for gonarthrosis. A 10-19-year follow-up of 314 cases.

During a 10-year period, 314 tibial osteotomies were performed for medial gonarthrosis. At follow-up after 10-19 years, 62 knees had been revised by arthroplasty (52 cases) or reosteotomy (10 cases). The revision rate was 54/170 in undercorrected knees and 8/144 in knees with normalization or overcorrection of the hip-knee-ankle angle. Our results confirm that tibial osteotomy for gonarthrosis requires proper indications and precise surgery. Perhaps, given another 10 years, our osteotomies will have outlived contemporary arthroplasties.

Female↗
PubMed1990

Disability in anterior cruciate ligament insufficiency. An analysis of 19 untreated patients.

We analyzed the knee function in 19 consecutive patients with chronic instability after an anterior cruciate ligament rupture. Muscle strength, standing balance, activity level, functional knee score, and a performance test were evaluated. Reduced quadriceps muscle strength compared with the noninjured limb was associated with reduced performance as measured by the one-leg hop test and the Lysholm knee score. No weakness in the hamstrings was found. The patients had impaired standing balance with increased body sway in the frontal plane when standing on both the injured and noninjured limb.

Adolescent↗
PubMed1990

Porous coated anatomic tricompartmental tibial components. The relationship between prosthetic position and micromotion.

Micromotion of the tibial component, both as migration over time and as inducible displacement in response to external physiologic forces, was studied in 20 cases of gonarthrosis. The patients had Porous Coated Anatomic primary total knee arthroplasty and were followed for four years. All cases but one were clinically successful. Thirteen components were inserted without cement, while in seven, high-viscosity Palacos cement was used. Full postoperative weight bearing was allowed in all cases. During the first year, noncemented components migrated a mean of 2.6 mm, while cemented components migrated a mean of 1.1 mm. About 1 mm of migration of noncemented components was in the downward direction, i.e., subsidence occurred, mostly during the first year. After one year, the noncemented components had stabilized more than the cemented ones. There was a significant correlation between the migration after one year and the postoperative prosthetic position and alignment of the leg. A mean maximum inducible displacement (the total vector displacement of the prosthetic marker that moved the most) of 0.7 mm and 0.4 mm was found for noncemented and cemented components, respectively. The micromotion found was of the same magnitude as that for other cemented and noncemented prosthetic systems previously reported.

Aged↗
PubMed1990

A long-term follow-up study of total meniscectomy in children.

The long-term effects of single meniscectomy in 89 children have been analyzed at an average of 16.8 years after surgery. Seventy-four percent were pleased with the outcome, but only 52% or 58% had objectively satisfactory results according to the two scoring systems used. Significantly poorer results were achieved with lateral meniscectomies. The range of movement was significantly decreased after lateral meniscectomy. Minor instabilities were recorded in 45% of the patients and major instabilities in 15%. Anteroposterior and rotatory instabilities were objectively measured, and a significant increase was noted in knees that had lateral meniscectomy. Grade I gonarthrosis was recorded in 39% of the surgically treated knees and Grades II and III gonarthroses in 9%. The joint space was significantly reduced in all knees irrespective of the injured compartment.

Adolescent↗
PubMed1989

A guide instrument for high tibial osteotomy.

Fifty-two patients (52 knees) with medial gonarthrosis were subjected to high tibial osteotomy using the Tjörnstrand guide instrument. The intended wedge was calculated from a whole lower limb radiograph. The correction aimed at was an overcorrection of 4 degrees in valgus of the hip-knee-ankle angle. All but 1 case were corrected to +/- 3 degrees of the intended angle. All but two cases healed within +/- 3 degrees of the achieved surgical correction, i.e., a substantial improvement compared with our previous freehand technique where one fifth were outside this interval. We conclude that in knee surgery a guide is as important for osteotomies as for arthroplasties.

Adult↗
PubMed1989

Lateral meniscal lesions in patients with clinically suspected medial lesions.

Double-contrast arthrography and arthroscopy were performed in a prospective study on 46 consecutive patients clinically suspected of having a medial meniscal tear only. At arthrography, 38 torn medial menisci were found; four of them were, however, false-positive and another false-negative as compared with arthroscopic examination. Moreover, seven unsuspected lateral meniscal tears were diagnosed at both arthrography and arthroscopy. The diagnostic accuracy of the double-contrast arthrography was well above the clinical accuracy, and we conclude that arthrography is a reliable method for diagnosing both medial and lateral tears.

Arthrography↗