Ragnhild Gunderson

Knee Function and Prevalence of Knee Osteoarthritis After Anterior Cruciate Ligament Reconstruction A Prospective Study With 10 to 15 Years of Follow-up

Background Few prospective long-term studies of more than 10 years have reported changes in knee function and radiologic outcomes after anterior cruciate ligament (ACL) reconstruction. Purpose To examine changes in knee function from 6 months to 10 to 15 years after ACL reconstruction and to compare knee function outcomes over time for subjects with isolated ACL injury with those with combined ACL and meniscal injury and/or chondral lesion. Furthermore, the aim was to compare the prevalence of radiographic and symptomatic radiographic knee osteoarthritis between subjects with isolated ACL injuries and those with combined ACL and meniscal and/or chondral lesions 10 to 15 years after ACL reconstruction. Study Design Cohort study; Level of evidence, 2. Methods Follow-up evaluations were performed on 221 subjects at 6 months, 1 year, 2 years, and 10 to 15 years after ACL reconstruction with bone-patellar tendon-bone autograft. Outcome measurements were KT-1000 arthrometer, Lachman and pivot shift tests, Cincinnati knee score, isokinetic muscle strength tests, hop tests, visual analog scale for pain, Tegner activity scale, and the Kellgren and Lawrence classification. Results One hundred eighty-one subjects (82%) were evaluated at the 10- to 15-year follow-up. A significant improvement over time was revealed for all prospective outcomes of knee function. No significant differences in knee function over time were detected between the isolated and combined injury groups. Subjects with combined injury had significantly higher prevalence of radiographic knee osteoarthritis compared with those with isolated injury (80% and 62%, P = .008), but no significant group differences were shown for symptomatic radiographic knee osteoarthritis (46% and 32%, P = .053). Conclusion An overall improvement in knee function outcomes was detected from 6 months to 10 to 15 years after ACL reconstruction for both those with isolated and combined ACL injury, but significantly higher prevalence of radiographic knee osteoarthritis was found for those with combined injuries.

Trunk muscle strength, cross-sectional area, and density in patients with chronic low back pain randomized to lumbar fusion or cognitive intervention and exercises.

Study Design. A randomized study. Objectives. To compare muscle strength, cross-sectional area, and density of the back muscles in two categories of patients with chronic low back pain, randomized to either lumbar fusion or cognitive intervention and exercises. Summary of Background Data. In two clinical trials, patients with chronic low back pain plus disc degeneration and postlaminectomy syndrome, respectively, were randomized to either lumbar fusion or cognitive intervention and exercises. We have previously reported that results for the primary outcome were similar at the 1-year follow-up examination. Methods. As the treatment alternatives and test procedures were identical, the two trials were merged into one. A total of 124 patients 25 to 60 years of age were included. Muscle strength, measured by isokinetic test device and by the Biering-Sørensen Test, was measured in 112 patients, and the cross-sectional area and density of the back muscles were measured in 61 patients at the inclusion and at the 1-year follow-up examination. Results. The exercise group performed significantly better in muscle strength than did the lumbar fusion group, with the mean difference at 184 Nm (95% confidence interval, 64–303 Nm; P = 0.003) and for the Biering-Sørensen Test 21 seconds (95% confidence interval, 6–36 seconds; P = 0.006). The density at L3–L4 decreased in the lumbar fusion group but remained unchanged in the exercise group. The mean difference was 5.3 HU (95% confidence interval, 1.1–9.5 HU; P = 0.01). The cross-sectional area was unchanged in both groups. Conclusions. Patients with chronic low back pain who followed cognitive intervention and exercise programs improved significantly in muscle strength compared with patients who underwent lumbar fusion. In the lumbar fusion group, density decreased significantly at L3–L4 compared with the exercise group.

Excellent results of HA coating on a grit-blasted stem: 245 patients followed for 8-12 years

We report the outcome of a grit-blasted titanium stem designed for press-fit insertion and entirely plasma sprayed with HA. During the years 1988-1993, we performed 323 primary total hip replacements in 276 patients (189 women) with a HA-coated prosthesis. Their mean age was 48 (15-79) years. During the follow-up, 12 patients died. 19 other patients did not attend the follow-up examination, but had no major symptoms according to telephone interviews and written replies. Thus, 245 patients (291 hips) were followed for a mean of 10 (8-12) years with radiographic and clinical examinations. Only 1 stem was revised due to mechanical failure. None were revised because of infection. Osteolysis was significantly associated with wear, and wear was significantly associated with the size of the femoral head. We found a small amount of proximal bone loss (37/291) and a low incidence of distal hypertrophy of the bone (23/291). These observations indicate an essentially physiological weight distribution from the stem to the femoral bone. The changes in the bone confirmed that the femoral component was well fixed in asymptomatic patients. To conclude, we found excellent 8-12-year results with a fully HA-coated femoral prosthesis designed for press-fit insertion.

Femoral shortening in total arthroplasty for completely dislocated hips:3–7 year results in 25 cases

During the years 1988-1991, we performed 25 total hip replacements for completely dislocated hips in 15 women and 4 men with a median age of 54 (17-67) years. In all cases, femoral shortening at the subtrochanteric level was performed to obtain reduction of the hip. The patients have been followed for 3-7 years. 1 patient experienced sciatic nerve palsy, 1 a delayed union and 1 a malunion at the osteotomy site. There were no signs of mechanical failure. All patients were satisfied. According to the Charnley hip score, function was excellent in 15 cases, good in 9 and fair in 1. The median Harris hip score improved from 43 at the time of operation to 93 at follow-up. 7 hips had a positive and 18 a negative Trendelenburg test. Before operation, all patients had a Trendelenburg limp. Our intermediate results indicate that femoral shortening at the subtrochanteric level is a suitable adjunct to total arthroplasty for a completely dislocated hip.

Reliability of computed tomography measurements of paraspinal muscle cross-sectional area and density in patients with chronic low back pain.

Study Design. A reliability study was conducted. Objective. To estimate measurement errors related to equipment and the observer in computed tomography measurements of cross-sectional area and density of paraspinal muscles. Interobserver reliability was not investigated in the current study. Summary of Background Data. Computer tomography (CT) had been used to measure the cross-sectional area and degeneration of the back muscles in patients with low back pain. Methods. This study included 31 patients, mean age 47 years, with chronic low back pain. The measurements comprised cross-sectional area (cm2) and density (Hounsfield units [HU]) of the paraspinal muscles at Th12–L1, L3–L4, and L4–L5. To measure the reliability of the equipment and the observer (total reliability), two independent CT scans were performed for each patient. The radiologist traced the cross-sectional area twice within 2 weeks for measurement of the intraobserver reliability. Results. There were no significant differences in the assessments between the first and second CT scans, or between the radiologist’s two measurements of the identical slices. The critical difference for the total reliability ranged from 11.3 to 22.8 for the density and from 10.0 to 16.0 for the cross-sectional area. For the cross-sectional area, the measurement error associated with the observer was higher than for the equipment. For the density, the measurement error related to the equipment was higher. The main measurement error was associated with the radiologist for the cross-sectional area and with the CT scanner for the density. Conclusions. The reliability of the CT scan for measuring the cross-sectional area and density of the back muscles is acceptable. The authors do not know definitely whether their results can be generalized because the interobserver and intermachine reliabilities were not investigated.

Failure of HA coating on a gritblasted acetabular cup: 155 patients followed for 7-10 years.

We report the outcome of 191 acetabular gritblasted titanium cups with a hemispherical design for press-fit insertion and coated with hydroxyapatite. The prosthesis was made of gritblasted titanium entirely coated with hydroxyapatite. 155 patients aged 15-78 years were operated on during the years 1991-1993 and followed for 7-10 years. During this period, 39 cups were revised because of mechanical loosening, a further 9 had radiolucent lines and 2 focal osteolysis. None of these 11 patients had clinical symptoms. Failure was associated with age, wear and radiolucency/osteolysis. At revision, we found that the soft tissues were discolored, and that most of the coating had disappeared. This design of hydroxyapatite-coated cups has a high rate of debonding and failure.

Quadriceps muscle weakness after anterior cruciate ligament reconstruction: A risk factor for knee osteoarthritis?

To identify risk factors for knee osteoarthritis (OA) 10–15 years after anterior cruciate ligament (ACL) reconstruction. We hypothesized that quadriceps muscle weakness after ACL reconstruction would be a risk factor for radiographic and symptomatic radiographic knee OA 10–15 years later.

Changes in Knee Osteoarthritis, Symptoms, and Function After Anterior Cruciate Ligament Reconstruction A 20-Year Prospective Follow-up Study

Background: Progression of tibiofemoral (TF) and patellofemoral (PF) osteoarthritis (OA) and changes in knee function more than 15 years after anterior cruciate ligament reconstruction (ACLR) are not well understood. Purpose: To examine the progression of knee OA and changes in symptoms and function in isolated and combined injuries from 15 to 20 years after ACLR. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 210 subjects with ACLR were prospectively followed. At the 15- and 20-year follow-ups, radiographs were obtained and classified by the Kellgren and Lawrence (K-L) grading system. Symptoms and function were evaluated with the Knee injury and Osteoarthritis Outcome Score (KOOS) as well as isokinetic quadriceps and hamstring muscle strength tests. Results: There were 168 subjects (80%) who returned for the 20-year follow-up, with a mean (±SD) age of 45 ± 9 years, mean body mass index of 27 ± 4, and median Tegner activity level of 4 (range, 0-9). The prevalence of radiographic TF and PF OA at the 20-year follow-up was 42% and 21%, respectively. Patients with ACL injuries and other combined injuries had significantly higher prevalence of radiographic TF OA compared with those who had isolated ACL injury (P < .0001). There was a 13% increase in radiographic TF OA (P = .001) and an 8% increase in PF OA (P = .015) from the 15- to the 20-year follow-up. A significant deterioration in knee symptoms and function was observed on the KOOS subscales (P ≤ .01), with the exception of quality of life (P = .14), as well as a decrease in quadriceps muscle strength and hamstring muscle strength (P < .0001). Conclusion: The prevalence of radiographic TF and PF OA was 42% and 21%, respectively. A significantly higher prevalence of TF OA was found for subjects with combined injuries compared with those who had isolated ACL injury. The majority of the subjects were stable radiographically over the 5 years between follow-ups. A statistically significant deterioration in symptoms and function was noted, but the mean changes were of questionable clinical importance.

The effect of comprehensive group training on cross-sectional area, density, and strength of paraspinal muscles in patients sick-listed for subacute low back pain.

The effect of exercise on back muscle cross-sectional area (CSA), density, and strength was evaluated in patients sick-listed for subacute low back pain. Twenty-four patients were randomized into an exercise (n = 11) or a control (n = 13) group. Patients in the exercise group followed a biweekly exercise protocol for 15 weeks. Control patients received usual care. Muscle CSA and density were measured by computed tomography before and after intervention. Isokinetic test of back extensors was conducted simultaneously. Results showed a tendency to increased muscle CSA and density in patients in the exercise group, a significant decrease in muscle CSA at L4–L5 in control group patients, and a significant difference in change between groups in muscle CSA at L4–L5. Back extension strength increased in patients in the exercise group, but the improvement was not significant compared with control group patients. In conclusion, there was a tendency for reversal of muscle atrophy after exercise.

Excellent results with femoral revision surgery using an extensively hydroxyapatite-coated stem: 59 patients followed for 10–16 years

Background The outcome of femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. We report long-term outcome of a grit-blasted titanium stem entirely plasma sprayed with hydroxyapatite (HA), in femoral revision surgery. Patients and methods During 1988 to 1993, we performed 66 femoral revisions in 65 patients (49 women) aged mean 58 (28–86) years. 3 patients died before the 10-year follow-up and 4 did not come for the follow-up examination because they had no hip problems, as confirmed by telephone and by a written reply. 1 of these, however, was previously controlled at 10 years. Thus, 59 patients (60 hips) were followed by clinical and radiographic analysis for 10–16 years after femoral stem revision. Results 1 stem was re-revised due to mechanical failure, and none were revised because of infection. We noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy. These observations indicate no significant net transfer of stress proximally to distally, and a somewhat physiological weight distribution from the stem to the femoral bone. The bone changes confirmed a well-fixed femoral component in asymptomatic patients. Interpretation Our findings indicate good long-term results with a fully HA-coated stem in femoral revision surgery. ▪