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.

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.

Polyethylene failure in two total knees. Wear of thin, metal-backed PCA tibial components.

Two women underwent a PCA total knee arthroplasty of the metal-backed type in which the tibial insert was only 4 mm thick in its thinnest portion. After 2 and 4 years, both women had pain on weight bearing due to polyethylene breakdown causing metal-to-metal contact. Such thin polyethylene components should not be used for knee replacements.

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.

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.

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.

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.

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.

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.

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.

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).

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.

Early knee mobilization after osteotomy for gonarthrosis.

In a prospective study, 32 knees in 32 patients were randomized to either a cylinder plaster cast (17 knees) or hinged cast-brace (15 knees) after high tibial osteotomy for medial gonarthrosis. At 6 weeks, 3 months, and still 1 year after surgery, the range of motion was better in the cast-brace group. There was no difference in the other clinical results at 3 months and at 1 year after surgery, nor in changes of osseous correction or in the final knee alignment.

Function after tibial osteotomy for medial gonarthrosis below aged 50 years.

Twenty-seven patients (28 knees), with a median age of 42 (27-50) years treated with a high tibial osteotomy for early medial gonarthrosis (Ahlbäck's Stage I) were examined after 11 (7-18) years. Twenty-four were men; 18 knees had had previous meniscus and ligament lesions. At follow-up, 22 knees were satisfactory and 9 patients managed high-activity sports or heavy work.

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.

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.

Analgesic efficacy and safety comparison of ketorolac tromethamine and Doleron for the alleviation of orthopaedic post-operative pain.

The analgesic efficacy and safety of ketorolac tromethamine (ketorolac), a potent analgesic with anti-inflammatory and antipyretic activities, were evaluated and compared with Doleron, a combination analgesic, in 115 patients with moderate to severe orthopaedic post-operative pain. This was a randomized, double-blind (double-dummy), parallel-group comparison of a single oral dose of one capsule of 10 mg ketorolac with a single oral dose of two Doleron tablets (each tablet contained 150 mg dextropropoxyphene napsylate, 350 mg aspirin and 150 mg phenazone). During the 6 h following treatment, 80% of ketorolac treated patients and 82% of Doleron treated patients experienced adequate pain relief.

A stabilometric technique for evaluation of lower limb instabilities.

Stabilometry is a technique designed to register postural equilibrium control. This investigation used a computerized strain gauge force plate to measure sway movements in the frontal plane with the patient standing on one leg. Fifty-five young healthy individuals were studied as a reference group and to determine the reproducibility of the method.

The PCA unicompartmental knee. A 1-4-year comparison of fixation with or without cement.

Totally, 93 knees were operated on with the PCA unicompartmental knee for gonarthrosis Stages I-III according to Ahlbäck. The clinical findings for 84 arthroplasties with 1-4 years' follow-up showed 82 excellent or good results. The mean postoperative flexion was 124 degrees.

Micromotion of noncemented Freeman-Samuelson knee prostheses in gonarthrosis. A roentgen-stereophotogrammetric analysis of eight successful cases.

Micromotion of the tibial component of eight Freeman-Samuelson arthroplasties without cement for gonarthrosis were followed for two years and studied by roentgen-stereophotogrammetric analysis (RSA). In five cases, displacement over time was studied, and in all cases migration was found to range from 0.7 to 4.

Micromotion of conventionally cemented all-polyethylene tibial components in total knee replacements. A roentgen stereophotogrammetric analysis of migration and inducible displacement.

Micromotion of the tibial component in 27 knee arthroplasties for gonarthrosis, three of which were regarded as failures for reasons other than mechanical loosening, was studied using high-resolution roentgen stereophotogrammetric analysis (RSA). Migration over time was found in all cases, ranging from 0.2 to 2.

Tibial component fixation in knee arthroplasty.

Using roentgen stereophotogrammetric analysis (RSA), the integrity of the bond between the tibial component and the tibia was studied in seven knees, implanted with a cemented Kinematic total knee prosthesis for gonarthrosis. Migration ranging from 0.3 to 1.

Survival of knee arthroplasties. A nation-wide multicentre investigation of 8000 cases.

A prospective nation-wide study of knee arthroplasty has been under way in Sweden since October 1975. By the end of 1983, 4505 arthroplasties for osteoarthritis and 3495 for rheumatoid arthritis had been recorded and reviewed one, three and six years after the operation. Using actuarial methods, the probability of the prosthesis remaining in situ after six years was calculated.