The influence of osteoporosis on varus osteoarthritis of the knee

Association of osteoporosis and varus inclination of the tibial plateau in postmenopausal women with advanced osteoarthritis of the knee

Background

Although varus inclination of the tibial plateau has increasingly been recognized as a major risk factor in the progression of Osteoarthritis of the knee (OA knee), little attention has been placed on the development of the varus inclination of the tibial plateau. Osteoporosis is a disease characterized by low bone mass and may increase the risk of a stress fracture in the proximal tibia. To date, risk factors for varus inclination of the tibial plateau are rarely reported. In this study, we investigated Bone Mineral Density (BMD) as a risk factor of varus inclination of the tibial plateau in postmenopausal women with advanced OA knee.

Methods

A total of 90 postmenopausal women with varus OA knee who had received a total knee arthroplasty in our department between January 2016 and December 2019 were reviewed. Certain factors may correlate to inclination of the tibial plateau (Medial Tibial Plateau Angle, MTPA), including age, operation side, Kellgren-Lawrence grade of OA knee, BMD, Body Mass Index (BMI), Lateral Distal Femur Angle (LDFA), lower extremity alignment (Hip-Knee-Ankle angle, HKAA), and history of both spinal compression fracture and hip fracture were collected and analyzed.

Results

Osteoporosis, lower extremity varus malalignment and age were significantly associated with varus inclination of the tibial plateau (MTPA) (P = 0.15, 0.013 and 0.033 respectively). For patients with a lower extremity varus malalignment (HKAA < 175°), osteoporosis (T-score ≤ -2.5) was significantly associated with inclination of the tibial plateau. For patients with a normal lower extremity alignment (HKAA ≥ 175°), no significant association was found between osteoporosis (T-score ≤ -2.5) and varus inclination of the tibial plateau.

Conclusions

Osteoporosis, lower extremity varus malalignment and age are major risk factors for inclination of the tibial plateau in postmenopausal women with OA knee. More attention needs to be given to the progression of varus OA knee in postmenopausal women who simultaneously has osteoporosis and lower extremity varus malalignment.

Case-related factors affecting cutting errors of the proximal tibia in total knee arthroplasty assessed by computer navigation

PURPOSE

The aim of this study was to determine factors that contribute to bone cutting errors of conventional instrumentation for tibial resection in total knee arthroplasty (TKA) as assessed by an image-free navigation system. The hypothesis is that preoperative varus alignment is a significant contributory factor to tibial bone cutting errors.

METHODS

This was a prospective study of a consecutive series of 72 TKAs. The amount of the tibial first-cut errors with reference to the planned cutting plane in both coronal and sagittal planes was measured by an image-free computer navigation system. Multiple regression models were developed with the amount of tibial cutting error in the coronal and sagittal planes as dependent variables and sex, age, disease, height, body mass index, preoperative alignment, patellar height (Insall-Salvati ratio) and preoperative flexion angle as independent variables.

RESULTS

Multiple regression analysis showed that sex (male gender) (R = 0.25 p = 0.047) and preoperative varus alignment (R = 0.42, p = 0.001) were positively associated with varus tibial cutting errors in the coronal plane. In the sagittal plane, none of the independent variables was significant.

CONCLUSION

When performing TKA in varus deformity, careful confirmation of the bone cutting surface should be performed to avoid varus alignment. The results of this study suggest technical considerations that can help a surgeon achieve more accurate component placement.

LEVEL OF EVIDENCE

IV.

Tibial condylar valgus osteotomy (TCVO) for osteoarthritis of the knee: 5-year clinical and radiological results

PURPOSE

Tibial condylar valgus osteotomy (TCVO) is a type of opening-wedge high tibial osteotomy for advanced medial knee osteoarthritis (OA) with subluxated lateral joint. We report the concept, the current surgical technique with a locking plate, and the short-term clinical and radiological results of this procedure.

METHODS

11 knees with medial OA and a widened lateral joint were treated by TCVO (KL stage III: 6, IV: 5). In this procedure, by the L-shaped osteotomy from the medial side of the proximal tibia to the intercondylar eminence and the valgus correction, lateralization of the mechanical axis and reduction of the subluxated lateral joint are obtained with early postoperative weight-bearing. Before, 6 months, 1, and 5 years after the operation, a visual analog scale (VAS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC), alignment of the lower extremity, and congruency and stability of the femorotibial joint were investigated.

RESULTS

The VAS improved from an average of 73 mm to 13 mm, and the total WOMAC score from 52 to 14 before to 5 years after the operation, respectively. The mechanical axis changed from 1 to 60%, and the FTA changed from 186° to 171°. The joint line convergence angle (JLCA) changed from 6° to 1°, and the angle difference of JLCA between varus and valgus stress improved from 8° to 4° after the procedure.

CONCLUSION

Improvements in pain and activities of daily living were observed by TCVO along with valgus correction of the lower extremity and stabilization of the femorotibial joint.

Spontaneous Osteonecrosis of the Knee: A Retrospective Analysis by Using MRI and DEXA

Objective:

Although there are many etiology and prediction for prognosis of spontaneous osteonecrosis of the knee (SONK) by using radiological examinations, these issue have not been clarified yet. Furthermore, most of the studies evaluated them by only radiological examination such as magnetic resonance imaging (MRI), bone mineral density (BMD) in dual-energy X-ray abosorptiometry (DEXA) or plain X-ray. Therefore, we focused our investigation on the measurements of the affected área in MRI and BMD in DEXA, and whether these results were conected with the cause and prognosis of SONK or not.

Method:

A consecutive case series of two groups composed of ten osteoporotic patients who were suffering from SONK was considered. Based on the severity or duration of pain, one group was treated with surgical procedure which was unicompartmental knee arthroplasty (UKA), the other received conservative treatment. Both groups underwent DEXA in their distal fêmur and próximal tíbia and all patients who took MRI measured the affected lesion in low and high intensity área on T2 weighted images. This data was analyzed from these areas and units.

Results:

Significant decrease in regional boné density of the affected femoral condyle compared to the unaffected side was observed. However, the boné mineral density in the affected side was similar in the non-operative and surgical group. The área of the lesion which showed in both low and high intensity indicated that the operation group was significantly larger than the conservative group on T2 weighted images.

Conclusion:

The cause and prognosis of SONK have a close relationship with the size of the affected lesion and decreased boné mineral density

Cartilage Degeneration and Alignment in Severe Varus Knee Osteoarthritis

OBJECTIVES

The aim of this study was to examine the relationship between cartilage, ligament, and meniscus degeneration and radiographic alignment in severe varus knee osteoarthritis in order to understand the development of varus knee osteoarthritis.

DESIGN

Fifty-three patients (71 knees) with primary varus knee osteoarthritis and who underwent total knee arthroplasty were selected for this study. There were 6 men and 47 women, with 40 right knees and 31 left knees studied; their mean age at operation was 73.5 years. The ligament, meniscus, degeneration of joint cartilage, and radiographic alignments were examined visually.

RESULTS

The tibial plateau-tibial shaft angle was larger if the condition of the cartilage in the lateral femoral condyle was worse. The femorotibial angle and tibial plateau-tibial shaft angle were larger if the conditions of the lateral meniscus or the cartilage in the lateral tibial plateau were worse.

CONCLUSION

Based on the results of this study, progression of varus knee osteoarthritis may occur in the following manner: medial knee osteoarthritis starts in the central portion of the medial tibial plateau, and accompanied by medial meniscal extrusion and anterior cruciate ligament rupture, cartilage degeneration expands from the anterior to the posterior in the medial tibial plateau. Bone attrition occurs in the medial tibial plateau, and the femoro-tibial angle and tibial plateau-tibial shaft angle increase. Therefore, the lateral intercondylar eminence injures the cartilage of the lateral femoral condyle in the longitudinal fissure type. Thereafter, the cartilage degeneration expands in the whole of the knee joints.

The Relationship between Osteoporosis and Osteoarthritis of the Knee: A Report of 2 Cases with Suspected Osteonecrosis

Knee specimens of two osteoporotic patients who underwent unilateral knee arthroplasty for suspected osteonecrosis of the knee were examined histologically. Preoperative findings of magnetic resonance images in both patients were consistent with the diagnosis of osteonecrosis of the medial femoral condyles, although plain X-rays showed minimal degenerative changes. In both patients, preoperative bone mineral densities of the femoral condyle and proximal tibia of the affected side were lower than those of the unaffected side. Pathological examination of the resected femoral condyle and proximal tibia showed almost intact joint cartilage, healing of the collapsed subchondral bone, and significant trabecular bone loss. Histologically, no evidence of osteonecrosis, including empty lacunae of the trabecular bone, was observed. These findings indicated that subchondral bone collapse caused by osteoporosis, but not osteonecrosis, initiated the osteoarthritic change of the affected knee. This report emphasizes that there may be cases of progressive local osteoarthritis caused by fracture of subchondral bone because of osteoporosis.

Prevalence and risk factors for knee osteoarthritis in elderly Japanese men and women

BACKGROUND

The aims of the present study were to examine the prevalence and risk factors for knee osteoarthritis in elderly Japanese men and women.

METHODS

We examined 598 of the 1513 inhabitants of Miyagawa village aged > or = 65 years (393 women, 205 men). Baseline data, obtained with standard questionnaires, included information on age, past history, sports activity, working, knee pain, smoking, and intakes of alcohol and milk. Bone mineral density of the forearm was measured using dual energy X-ray absorptiometry. Anteroposterior radiographs of both knees were graded for osteoarthritis using the Kellgren-Lawrence grading system. Definite osteoarthritis was defined as a grade of 2 or higher. We used logistic regression analysis by the stepwise method to determine the risk factors for radiographic knee osteoarthritis.

RESULTS

The prevalence of definite radiographic knee osteoarthritis was 30.0% overall: 17.7% in men and 36.5% in women. The prevalence of symptomatic knee osteoarthritis was 21.2% overall: 10.7% in men and 26.7% in women. There were significant differences in the risk of radiographic knee osteoarthritis with body mass index (BMI), sex, age, and bone mineral density (BMD).

CONCLUSIONS

The prevalence of definite radiographic knee osteoarthritis was 30.0% and that of symptomatic knee osteoarthritis was 21.2%. We found that higher BMI, female sex, older age, and higher BMD were significantly associated with an increased risk for radiographic knee osteoarthritis.

Bone mineral density is not related to severity of osteoarthritis in the knee in postmenopausal women

Although some studies have suggested that osteoporosis and osteoarthritis are inversely related in epidemiologic terms, a spectrum of relations between the two diseases has been described in this study. In 95 postmenopausal women (mean age 64.4 +/- 8.49 years, range 49-83 years), we investigated the relation between bone mineral density (BMD) in the femoral neck and lumbar vertebrae (L2-L4) and osteoarthritis in the knee. BMD was measured with dual X-ray absorptiometry. Osteoarthritis was evaluated with anterior-posterior weight-bearing radiographs with the knee in extension, and these were graded for severity on a 5-point scale according to the Kellgren-Lawrence criteria. We found no clear statistical relation between BMD in the femoral neck or lumbar vertebrae and osteoarthritis in the knee. Given that some studies have found BMD to be significantly higher in patients with osteoarthritis, the lack of such relation in our patients may be due to environmental and/or genetic factors.

Osteoarthritis of the hip and knee: sex and gender differences

Osteoarthritis of the hip and knee is a leading cause of functional disability and compromised quality of life in older patients and a significant public health issue. Emerging research shows sex and gender differences in osteoarthritis which, to date, may not be appreciated by the orthopedic community. This article discusses sex and gender differences in osteoarthritis with a focus on disease involving the hip and knee. Understanding what we know (and do not know) about sex and gender differences in this disorder is critical to improving quality of care for our patients.

Ethnic-, gender-, and age-related differences in femorotibial angle, femoral antetorsion, and tibiofibular torsion: cross-sectional study among healthy Japanese and Australian Caucasians

The current study was conducted to examine ethnic, gender, and age-related differences in femorotibial angle (FTA), femoral antetorsion and tibiofibular torsion. Healthy Japanese (n = 120) and Australian Caucasian (n = 82) subjects were examined using a series of clinically reliable methods for measuring FTA and torsion of the lower limb. Subjects between 18-29 years of age were categorized as younger, 30-59 years as middle age, and 60 or more as older age. Three-way analysis of variance was utilized for data analysis. The Japanese subjects had significantly greater FTA (more varus) than the Australian subjects (P < 0.001). Femoral antetorsion in the Japanese subjects was significantly smaller in middle and older age groups than younger group (P < 0.05), but did not differ between the age groups in the Australian subjects. Further, tibiofibular torsion in female subjects was significantly greater in younger and middle age groups than the older age group (P < 0.01), but was not different between different age groups in males. The results suggest that healthy Japanese may have more genu varus alignment compared to the corresponding Australian population. Age-related ethnic and gender differences in femoral and tibiofibular torsion are worthy of further study.

Determinants of self efficacy for physical tasks in people with knee osteoarthritis

OBJECTIVE

Self efficacy, the confidence an individual has to perform a task, is an important determinant of physical performance in individuals with knee osteoarthritis (OA). The purpose of this study was to determine what personal, pathophysiologic, and impairment factors relate to self efficacy for physical tasks in community-dwelling adults with knee OA.

METHODS

Fifty-four persons with radiographically confirmed knee OA (mean +/- SD age 68.3 +/- 8.7 years, range 50-87 years) participated. The Functional Self-Efficacy subscale of the Arthritis Self-Efficacy Scale was the dependent measure. Independent measures included age, education, scores from the Center for Epidemiologic Studies Depression and State-Trait Anxiety Inventory questionnaires, medial joint space and varus/valgus tibiofemoral angle from radiographs, body mass index, and isokinetic quadriceps and hamstrings strength. Knee pain and stiffness, assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, were independent measures.

RESULTS

Fifty-one percent of the variance of Functional Self Efficacy was explained by knee stiffness, hamstrings strength, age, and depression scores. Pain, education, anxiety, radiographic joint space, and body weight did not significantly contribute to the variance in Functional Self-Efficacy scores. Substituting quadriceps strength for hamstrings strength resulted in a regression model that included only stiffness, age, and depression, which explained nearly as much variance as the original model.

CONCLUSION

Self efficacy for physical tasks is related to the sensation of stiffness, hamstrings strength, age, and level of depressive symptoms in persons with knee OA. Clinicians and researchers could consider these variables when assessing the level of self efficacy for physical tasks in persons with knee OA.

Static and dynamic biomechanics of foot orthoses in people with medial compartment knee osteoarthritis

OBJECTIVE

Gait biomechanics (knee adduction moment, center of pressure) and static alignment were investigated to determine the mechanical effect of foot orthoses in people with medial compartment knee osteoarthritis.

DESIGN

Repeated measures design in which subjects were exposed to three conditions (normal footwear, heel wedge and orthosis) in random order.

BACKGROUND

The knee adduction moment is an indirect measure of medial compartment loading. It was hypothesized that the use of a 5 degrees valgus wedge and 5 degrees valgus modified orthosis would shift the center of pressure laterally during walking, thereby decreasing the adduction moment arm and the adduction moment.

METHODS

Peak knee adduction moment and center of pressure excursion were obtained in nine subjects with medial compartment knee OA during level walking using an optoelectric system and force plate. Static radiographs were taken in 12 subjects using precision radiographs.

RESULTS

There was no difference between conditions in static alignment, the peak adduction moment or excursion of the center of pressure in the medial-lateral direction. No relationship was found between the adduction moment and center of pressure excursion in the medial-lateral plane. The displacement of the center of pressure in the anterior-posterior direction, measured relative to the laboratory coordinate system, was decreased with the orthosis compared to the control condition (P=0.036) and this measure was correlated with the adduction moment (r=0.45, P=0.019).

CONCLUSIONS

The proposed mechanism was not supported by the findings. The reduction in the center of pressure excursion in the anterior-posterior direction suggests that foot positioning was altered, possibly to a toe-out position, while subjects wore the orthoses. Based on the current findings, we hypothesize that toe-out positioning may reduce medial joint load.

RELEVANCE

Knee Osteoarthritis is the most common cause of chronic disability amongst seniors. Developing inexpensive, non-invasive treatment strategies for this large population has potential to impact health care costs, quality of life and clinical outcomes.

Forearm bone mineral density in postmenopausal women with osteoarthritis of the knee

The aims of the present study were to clarify whether postmenopausal women with osteoarthritis (OA) of the knee show higher bone mineral density (BMD) than healthy controls, and to investigate the relationship between BMD and the Kellgren and Lawrence radiological grade in postmenopausal women with OA of the knee. A total of 674 postmenopausal women, 46-90 years of age, were enrolled in the study: 305 patients with OA of the knee and 369 healthy controls. Forearm (distal radius) BMD, measured by dual-energy X-ray absorptionetry (DXA), using a DTX-200 (Osteometer), was significantly higher in the OA group than in the control group (P < 0.001), even when adjusted for age, height, body weight, body mass index, years since menopause, and grip strength (P < 0.01). Analysis of variance (ANOVA) with Fisher's protected least significant difference (PLSD) test showed that BMD in radiological grades 2, 3, and 4 was significantly higher than that in grade 1 (P < 0.05, P < 0.001, and P < 0.05, respectively), and BMD in grade 3 was significantly higher than that in grade 2 (P < 0.01), but BMD in grade 4 was significantly lower than that in grade 3 (P < 0.05). These findings suggest that forearm BMD appears to be significantly higher in postmenopausal women with OA of the knee than in healthy controls. Although BMD may be increased in low to moderate radiological grades of OA, severe grade OA may not always develop from moderate grade OA. Some cases of severe grade OA may be associated with low BMD.

Periprosthetic tibial fractures after cementless low contact stress total knee arthroplasty

Periprosthetic fractures are a recognized complication of total knee arthroplasty. Fractures may occur intraoperatively or postoperatively, and risk factors have been identified that may predispose an individual to such a complication. We report 7 cases of periprosthetic tibial fractures after low contact stress total knee arthroplasty, a complication encountered by the senior author (D.E.B.) only after a change in practice from a cemented implant to a cementless one. In light of this previously unreported complication in our unit, we attempted to identify common features within this group of patients that may have contributed to fracture occurrence. Statistical analysis revealed a highly significant (P<.005) risk of periprosthetic tibial fracture in patients with a preoperative neutral or valgus knee. Age, gender, and diagnosis did not appear to increase the risk of fracture significantly. All patients displayed evidence of reduced bone mineral density in the lumbar spine and femoral neck regions on dual-energy x-ray absorptiometry scanning. Patients with a preoperative neutral or valgus knee and local evidence of osteopenia represent a high-risk group, in whom particular care in alignment should be taken. In this group, it may be preferable to have the tibial component inserted with cement fixation.

Relationships among bone mineral densities, static alignment and dynamic load in patients with medial compartment knee osteoarthritis

OBJECTIVE

To investigate the relationships among bone mineral density (BMD), static alignment and the adduction moment of the knee in patients with tibiofemoral osteoarthritis (OA).

METHODS

Sixty-nine patients with medial compartment knee OA underwent radiographic evaluation, gait analysis and BMD measurements at the proximal tibia and lumbar spine.

RESULTS

The bone mineral distribution of the medial to lateral part of the proximal tibia correlated significantly with the peak knee adduction moment and the mechanical axis. Furthermore, the adduction moment correlated significantly with the mechanical axis. However, the BMD of the lumbar spine and the bone mineral distribution of the posterior to anterior part of the proximal tibia did not correlate with any other measurement.

CONCLUSIONS

Our results suggest that the bone mineral distribution of the proximal tibia is directly affected but lumbar BMD is not influenced by the local mechanical stress around the knee with medial compartment OA.