Factors associated with physical activity following total knee arthroplasty for knee osteoarthritis: a longitudinal study.

BACKGROUND: After total knee arthroplasty (TKA), patients' physical activity (PA) levels at 6 months are lower than those of healthy subjects. Few studies have investigated the factors associated with PA at 6 months after TKA by objectively measuring preoperative and postoperative PA intensity using an accelerometer and knee function using a goniometer and dynamometer. The purpose of this study was to determine the factors associated with PA levels at 6 months after TKA based on objective data. METHODS: Eighty-two patients (mean [SD] age 74.5 [6.4] years) with moderate-to-severe knee osteoarthritis (OA) who were scheduled for TKA at the Nagoya Orthopaedic and Joint Replacement Clinic from July 2018 to July 2019 were enrolled in this longitudinal study. All patients underwent evaluations of knee function, including range-of-motion and knee-extension muscle strength; knee pain; performance in the timed up-and-go test; and accelerometer-measured PA both preoperatively and 6 months postoperatively. Factors associated with PA at 6 months after TKA were assessed using a hierarchical multiple linear regression analysis adjusted for age, sex, body mass index, and presence of diabetes mellitus. RESULTS: A higher average daily step count at 6 months after TKA was significantly associated with greater preoperative knee-extension muscle strength on the operated side (ß = 0.155, p = 0.028) as well as a higher preoperative average daily step count (ß = 0.834, p < 0.001). Furthermore, average daily time spent in moderate-to-vigorous-intensity PA postoperatively was significantly associated only with time spent in moderate-to-vigorous-intensity PA preoperatively (ß = 0.723, p < 0.001). CONCLUSION: These findings indicate that a higher preoperative daily step count and greater preoperative knee-extension muscle strength on the operated side may be associated with a higher daily step count at 6 months after TKA. Factors associated with PA differed by the PA intensity level. Rehabilitation and interventions for psychosocial factors before TKA beginning when mild knee OA first occurs are expected to lead to increased PA in TKA patients.

Effect of diabetes mellitus on physical activity in patients with knee osteoarthritis: A cross-sectional study.

PURPOSE: Knee osteoarthritis (OA) may be comorbid with diabetes mellitus (DM), and physical activity is a recommended lifestyle strategy for both diseases. The present study investigated the physical activity differences by intensity between knee OA patients with or without DM, and evaluated if physical activity was associated with the presence of DM in knee OA patients. METHODS: A total of 183 patients (mean age 74.9 ± 6.4 years) with moderate-to-severe knee OA underwent evaluation of knee function (i.e., knee flexion/extension range-of-motion, knee-extension muscle strength, and knee pain), the timed up-and-go (TUG) test, and physical activity measurement using an accelerometer. Physical activity by intensity was compared between knee OA patients with and without DM. The association between physical activity, including knee function and the TUG test time, and DM was assessed. RESULTS: The 2 groups (with or without DM) did not differ significantly in knee OA severity or age. Compared to knee OA patients without DM, knee OA patients with DM had a significantly lower average daily step count (p < 0.001), and significantly shorter times spent performing light-intensity physical activity (LPA; p < 0.001) and moderate-to-vigorous-intensity physical activity (MVPA; p = 0.006). After adjusting for age, sex, and body mass index, we found that a lower average daily step count and shorter LPA time significantly correlated with DM (ß = -0.200, p = 0.006; ß = -0.216, p = 0.004, respectively) and a longer TUG test time (ß = -0.196, p = 0.014; ß = -0.208, p = 0.011, respectively). A shorter MVPA time significantly correlated with lower contralateral knee-extension muscle strength (ß = 0.187, p = 0.032). CONCLUSION: Knee OA patients with DM had significantly lower physical activity levels than those without DM. Furthermore, the presence of DM correlated with a lower step count and a shorter LPA time in knee OA patients.

Measurement of the normal contralateral hip flexion angle and posterior pelvic tilt angle using a pelvic guide pin in total hip arthroplasty.

BACKGROUND: We aimed to measure the posterior pelvic tilt angle at maximum hip flexion and hip flexion range of motion at the femoroacetabular joint using a pelvic guide pin and to examine the difference in flexion range of motion when determined by a physical therapist and under anesthesia. METHODS: Data of 83 consecutive patients undergoing primary unilateral total hip arthroplasty were assessed. Using a pin inserted into the iliac crest to define the cup placement angle under anesthesia before and after total hip arthroplasty, the posterior pelvic tilt angle was determined as the change in pin tilt from the supine position to maximum hip flexion. Flexion range of motion under anesthesia was calculated as the difference in the angle between the trunk and thigh at maximum flexion and the posterior pelvic tilt angle. Flexion range of motion with a fixed pelvis measured preoperatively by a physical therapist was compared to that under anesthesia. A goniometer was used for all measurements and the number of measurements was one. FINDINGS: Mean posterior pelvic tilt angle of the pin inserted into the pelvis under anesthesia was 15.8° ± 5.3° (3°-26°) preoperatively and 12.1° ± 4.9° (3°-26°) postoperatively. Mean flexion range of motion under anesthesia was 109.4° ± 6.9° (88°-126°) and that measured by a physical therapist was 101.1° ± 8.2° (80°-120°); the difference was significant (9.7°; p < 0.01). INTERPRETATION: These results highlight the difficulty in accurately determining hip flexion angles without the use of special devices and may help surgeons and physical therapists recognize and address this issue.

Comparison of weight-bearing full-length radiography and three-dimensional computed tomography scan-based models to assess knee joint coronal alignment following total knee arthroplasty.

BACKGROUND: The validity of standing long-leg radiography (LLR) - the standard method for evaluating coronal alignment after total knee arthroplasty (TKA) - remains controversial. We evaluated the measurement reliability and validity of LLR following TKA by comparing postoperative radiographs with three-dimensional computed tomography (3DCT) scans of the lower extremities. METHODS: We retrospectively collected the data of 55 knees from 44 patients who underwent postoperative 3DCT and 5-day and 6-month LLR for coronal alignment evaluation following TKA. The coronal femoral component angle (CFA) and coronal tibial component angle (CTA) were measured using 3DCT and LLR images. Correlations between the hip-knee-ankle angle (HKAA), CFA and CTA were analysed using Pearson's correlation coefficient (PCC); Bland-Altman plots were constructed to assess agreement between 5-day and 6-month radiographic and 3DCT scan measurements. RESULTS: The mean difference in HKAA between 3DCT, and 5-day and 6-month LLR was 1.3 ± 1° and 1.1 ± 0.7°, respectively. Differences of >1° in HKAA between 3DCT, and 5-day and 6-month LLR were observed in 31 (56.4%) and 28 (50.9%) knees, respectively; differences of >2° in these parameters were observed in 15 (27.3%) and nine (16.4%) knees, respectively. The 3DCT scan and radiograph measurements of HKAA, CFA and CTA were strongly correlated (PCC, 0.81-0.92; P < 0.001). Bland-Altman plot validity was within acceptable limits. CONCLUSION: LLR shows good reliability and validity for measuring coronal alignment. When comparing 3DCT scans and radiographs, a high number of HKAA values differed by more than 1° and 2°; this indicates that rigorous alignment evaluation requires 3DCT measurements.

Medial pivot-based total knee arthroplasty achieves better clinical outcomes than posterior-stabilised total knee arthroplasty.

PURPOSE: Stability in the sagittal plane, particularly regarding anterior cruciate ligament compensation, and postoperative functionality and satisfaction remain issues in total knee arthroplasty. Therefore, this prospective study compared the clinical outcomes between medial-pivot-based and posterior-stabilised total knee arthroplasty based on anterior translation and clinical scores. METHODS: To assess outcomes of total knee arthroplasty for varus osteoarthritis, the anterior translation distance of the tibia relative to the femur was measured at 30 and 60° of flexion using a KS measure Arthrometer at 6 months postoperatively. The 2011 Knee Society Score, Forgotten Joint Score, visual analogue scale for pain, and range of motion were assessed at 6 months and 1 year postoperatively. The correlations among each score, anterior translation distance, range of motion, and visual analogue scale score for pain were investigated. RESULTS: The medial-pivot and posterior-stabilised groups comprised 70 and 51 patients, respectively. The medial-pivot group exhibited a significantly shorter anterior translation distance at 60° flexion than the posterior-stabilised group. Furthermore, the medial-pivot group achieved significantly better outcomes regarding the visual analogue scale for pain, 2011 Knee Society Score, and Forgotten Joint Score than the posterior-stabilised group. A significant negative correlation was observed between the anterior translation distance and the function score of the 2011 Knee Society Score, whereas a significant positive correlation was found between the anterior translation distance and flexion angle, and between the extension angle and score of the Forgotten Joint Score or 2011 Knee Society Score. Significant negative correlations were also found between the pain visual analogue scale and both the 2011 Knee Society Score and Forgotten Joint Score. CONCLUSION: In total knee arthroplasty for osteoarthritis, the medial-pivot group displayed a shorter anterior translation distance than the posterior-stabilised group at 6 months postoperatively. The visual analogue scale score for pain was also significantly lower in the medial-pivot group than that in the posterior-stabilised group at both 6 months and 1 year postoperatively. Because a correlation was observed between the anterior translation distance and the function score, medial-pivot-based total knee arthroplasty was considered to significantly improve postoperative function compared to posterior-stabilised total knee arthroplasty.

Localization of the ilioischial line on axial computed tomography images for preoperative planning of total hip arthroplasty.

BACKGROUND: If the bony region indicating the ilioischial line is established on the preoperative axial computed tomography (CT) image, the distance between the simulated cup and the ilioischial line can be measured on this image so that the surgeon can use these data to define a more accurate preoperative two-dimensional (2D) template of total hip arthroplasty (THA). This study aimed to verify the hypothesis that on the CT axial image, the cortical bone area, indicated by the superimposition of a line (line α) with a perspective projection angle to the ilioischial line on radiography and tangent to the medial acetabular wall, is the cortical bone that represents the ilioischial line on radiography. METHODS: Study 1: If the two measured distances (distance A' and distance B) are sufficiently equal, then the hypothesis can be supported. Distance A' was calculated by multiplying the distance A, between the ilioischial line and the medial margin of the metal cup after THA measured at the level of the hip joint center on the pelvic radiograph, by 0.91 to correct for radiographic magnification. Distance B was defined as the distance between the medial margin of the metal cup and line α on the axial CT image at the level of the hip joint center. These two distances were measured for all 51 hip joints included in the study. Study 2: The difference between distance A and distance A# (distance A on the 2D template) was compared between the group containing 59 primary THAs in which distance B' was measured (distance B in the simulation) and the control group containing 59 primary THAs. RESULTS: Study 1: The average distance for A' was 4.5 ± 2 mm, and the average distance for B was 4.7 ± 2.1 mm. The difference between distances A and B was 0.2 ± 0.2 mm. Study 2: The mean difference between distance A and distance A# for the measurement and control groups was 1.8 ± 1.3 mm and 3.7 ± 2.4 mm, respectively (P < 0.001). CONCLUSIONS: The ilioischial line is located in the bony region where line α intersects the medial acetabular wall with a maximum overlap on axial CT images.

Calcaneal insufficiency fractures following ipsilateral total knee arthroplasty.

INTRODUCTION: Only a few reports have described calcaneal insufficiency fractures (IFs) following total knee arthroplasty (TKA). Herein, we describe nine cases of calcaneal IFs following ipsilateral TKA. The purpose of this study was to investigate the incidence of calcaneal fractures following TKA and determine the characteristics of patients with IFs. PATIENTS AND METHODS: We retrospectively investigated cases of calcaneal IF that occurred following TKA. We collected and analyzed radiographic and magnetic resonance imaging (MRI) findings as well as patient demographic data. We compared the demographic data, bone mineral density (BMD), and preoperative hip-knee-ankle angle (HKA) between cases with a calcaneal fracture following TKA and 100 cases without a fracture following TKA. RESULTS: We performed a total of 1548 knee arthroplasties at our clinic from 2011 to 2020. Nine calcaneal IFs in eight patients were diagnosed following ipsilateral TKA. All patients were women with varus knee osteoarthritis (mean age, 71.8 years). The average change in the alignment angle was 14.7° ± 5.4°. In eight cases, dysfunction was observed in the opposite lower limb. The postoperative onset of hindfoot pain started at an average of 5.6 months. In seven patients, calcaneal fractures occurred idiopathically, but in one patient, two fractures occurred after long-distance walking. No abnormal findings on a calcaneus radiograph were seen for six fractures. MRI demonstrated a definite fracture line and bone marrow edema in all patients. All patients, except one with type 2 diabetes mellitus (T2DM), had osteoporosis. Fractures healed without complications in eight patients; however, the calcaneal anterior facet fracture became displaced and caused a flat foot in one case. The calcaneal IF rate was 0.58% among all cases. Besides one case with T2DM, significant differences were observed in preoperative HKA and BMD between cases with a calcaneal fracture following TKA and those without a fracture. CONCLUSIONS: A change in the load on the calcaneus due to changes in the alignment of the lower extremities after TKA may cause calcaneal IFs. Orthopedic surgeons should be aware of the possible occurrence of calcaneal IFs following TKA, especially in women with osteoporosis and severe varus knee.

Intraoperative migration of the trial femoral head into the pelvis during total hip arthroplasty--report of two cases.

Various complications occur during total hip arthroplasty (THA). It is common to implement trial treatments of various implants during THA. Here we report on 2 cases in which the trial femoral head fell into the pelvis and migrated during THA. The trial head was not retrieved but left inside in one case, while the other presented the opportunity for a possible retrieval. It is important to recognize the existence of such rare complications.

Expression of inflammatory cytokines, RANKL and OPG induced by titanium, cobalt-chromium and polyethylene particles.

Bone resorption is regulated by cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1beta) and by the balance of a receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG). The aim of this study was to investigate the mechanism of particle-induced osteolysis in murine calvariae by assessing the extent of osteolysis and the expression of inflammatory cytokines, RANKL and OPG after implantation of metal and polyethylene particles. The murine calvariae implanted with Ti6Al4V, CoCr or high-density polyethylene (HDP) particles showed significantly more extensive osteolysis and elevated levels of inflammatory cytokines. The ratio between RANKL and OPG was high in the mice implanted with Ti6Al4V and HDP particles, but not in the mice implanted with CoCr particles. These observations suggested that CoCr particle-induced osteoclastogenesis may be caused directly by inflammatory cytokines rather than by the RANKL-RANK pathway. There might be different mechanisms at work in particle-induced osteolysis between Ti6Al4V, HDP and CoCr.

The unstable total hip replacement.

Instability after total hip arthroplasty (THA) is not a rare occurrence. Numerous factors have been associated with dislocation including surgical approach, implant design, failure to restore proper hip mechanics and soft tissue restraints, and patient variables such as early postoperative compliance, soft tissue integrity, and neurologic conditions such as poor proprioception. A thorough understanding of the mechanism of dislocation, timing, and direction of dislocation is mandatory in formulating an approach toward treatment. The radiographic evaluation should evaluate hip mechanics including component orientation, adequacy of leg lengths, and restoration of offset in the frontal and sagittal planes. The treatment of the unstable total hip replacement is based on numerous variables including the timing of instability, direction, and mechanism. Instability in the early postoperative period in the hip with proper orientation and restored mechanics often is treated successfully with patient reeducation and use of adjunctive bracing. The treatment of the recurrent dislocator can be more difficult. Although reestablishing proper mechanics and orientation can be successful in many instances, some patients continue to have dislocation. Constrained acetabular liners have significantly improved the success rate of reducing the incidence of dislocation, but problems related to premature wear and dislodgement are a major concern. The use of larger articulating bearing surfaces used with the newer cross-linked polyethylene may provide the solution to instability minimizing the concerns related to constrained components.

Early head penetration into cemented Hylamer Ogee socket.

The authors reviewed 18 consecutive cemented total hip arthroplasties with the Hylamer Ogee socket. The average follow-up period was 47 months. All Hylamer Ogee sockets were sterilized by gamma irradiation in air, and the average period from production to surgery was 12 months. Two-dimensional penetration of the femoral head into the Hylamer Ogee socket was determined from anteroposterior radiographs of the pelvis using a digitizer. The average head penetration rate of the present series was 0.36 mm/y. Osteolysis around both components was found in 6 cases (30%). Of 4 cases defined as aseptic loosening, 2 were revised during the follow-up period. To detect component loosening because of catastrophic high wear of the cemented Hylamer Ogee socket as early as possible, precise radiographic follow-up is essential.

Experimental evaluation of the usefulness of osteochondral allograft for articular cartilage defect.

This study was conducted to evaluate the usefulness of osteochondral allografts for articular cartilage defects. Cartilaginous defects measuring 4.5 mm in diameter were experimentally prepared in both the weight-bearing and non-weight-bearing regions of the femur in six male miniature pigs (9 months old). Osteochondral grafting was performed using fresh autografts (group AU), fresh allografts (group AL), or frozen allografts (group FA). Untreated cartilaginous defects were used as the control (group D). All the pigs were killed 4 weeks later, and the respective osteochondral grafts were macro- and microscopically evaluated. Hematoxylin and eosin staining, safranin O staining, and immunostaining [matrix metalloprotease-1 (MMP-1) and tissue inhibitor of metalloprotease-2 (TIMP-2)] were used for the histological evaluations of transplanted cartilage. Macroscopic and microscopic findings were assessed according to the criteria proposed by Wakitani et al. Although groups AU and AL showed similar median scores (ranges) for the evaluation of cartilaginous defect restoration, groups FA and D showed unfavorable scores: 3.9 (0-9) in group AU; 4.5 (0-12) in group AL; 10.2 (4-12) in group FA; and 7.0 (5-11) in group D. Immunostaining revealed almost identical results in groups AU and AL. As there were no histologically significant differences in the status of the osteochondral grafts between fresh autografts and fresh allografts, fresh allografts might be useful donor osteochondral grafts.

Biological reaction to alumina, zirconia, titanium and polyethylene particles implanted onto murine calvaria.

Periprosthetic osteolysis is a serious problem that limits long-term survival of total hip arthroplasty. Ceramics have been introduced as a joint surface material to reduce osteolysis due to wear particles. The aim of this study is to investigate the biological reaction of ceramic particles on murine calvarial bone, in comparison with polyethylene and titanium particles. Sixty CL/BL6 mice were divided into five groups according to the materials implanted onto the murine calvariae: control, Al(2)O(3), ZrO(2), high-density polyethylene (HDP) and Ti6Al4V. One week after the implantation, each calvarial tissue was dissected and the release of proinflammatory mediators (IL-1beta, IL-6, TNF-alpha) and bone resorption were assessed. The particles of HDP and Ti6Al4V induced three and two times larger osteolytic lesions than the control, respectively. The levels of IL-1beta and IL-6 were significantly elevated in the medium subcultured with the calvariae of HDP and Ti6Al4V groups. Any particle type did not increase the levels of TNF-alpha. There were no significant differences observed in the levels of proinflammatory mediators or osteolytic area among Al(2)O(3), ZrO(2) and control groups. The inflammatory response and bone resorption induced by ceramic particles were much smaller than those induced by HDP and Ti6Al4V. These biological features suggest the biocompatibility of ceramics as a joint surface material for artificial joints.

Quality of life after several treatments for osteoarthritis of the hip.

The purpose of this study was to examine quality of life (QOL) after a rotational acetabular osteotomy (RAO), primary total hip arthroplasty (THA), or conservative treatment (Conservative). A series of 147 patients with osteoarthritis of the hip were grouped according to treatment into the RAO group ( n = 62), THA group ( n = 40), and Conservative group ( n = 45) (treated with medication and rehabilitation alone). The mean age of the RAO group was 40 years, the THA group 54 years, and the Conservative group 50 years. The mean follow-up periods were 3.6, 3.9, and 3.3 years, respectively. All patients were female. As a control group 609 volunteers participating in a town mass screening program were recruited. QOL was determined using the Nottingham Health Profile (NHP). Each area of QOL was evaluated separately in all of the treatment groups at less than 1 year after therapy, at more than 1 year but less than 5 years, and at more than 5 years. With regard to QOL at less than 1 year after therapy, the Conservative group had significantly higher scores for energy, pain, and emotional reaction than the Control group. With regard to physical mobility, all of the treatment groups showed significantly higher scores than the Control group. With regard to QOL at more than 1 year but less than 5 years, the RAO and THA groups showed significantly higher scores than the Control group regarding physical mobility. Regarding pain, the RAO and Conservative groups showed significantly higher scores than the Control group. With regard to QOL at more than 5 years, for physical mobility all of the treatment groups showed significantly higher scores than the Control group. For pain the RAO group showed significantly higher scores than the Control group. NHP is a useful means for evaluating QOL in patients treated for osteoarthritis of the hip.

The long-term behavior of poly-L-lactide screws in a minipig fracture model: preliminary report.

The long-term degradation tissue response to poly-L-lactide (PLLA) screw was investigated for a minipig tibia fracture. As a bone-fracture model, three PLLA screws per animal were used to fix a tibia that had been subjected to a crank-shaped osteotomy. A total of 12 nine-month-old male minipigs were used. In time period from 1 month to 3 years, clinical, radiographic, and pathological studies were conducted. On macroscopic examination, no clear granuloma or fistula formation was noted for 3 years. On microscopic examination, no osteoclasts or giant cells were detected around the screws during the 3 years postoperatively. A substantial degradation of PLLA screw was observed between 2 and 3 years. At 3 years only slight residual breakdown products were found in macrophages. On electric microscopic examination, numerous degraded polymers were seen in a small number of macrophages around the screws. In this model, fixation of tibia fractures using PLLA screws was not associated with any side effects, and was safe and useful for up to 3 years.

Total hip arthroplasty for a patient with angel-shaped phalango-epiphyseal dysplasia (ASPED). A case report.

Angel-shaped phalango-epiphyseal dysplasia is characterized by the angel shape of the middle phalanx and severe coxarthrosis in adult life. This osteochondrodysplasia shows a further variety of heterogeneous multiple epiphyseal dysplasias. It also shows a late and dysplastic development of the femoral head that leads to osteoarthrotic changes with severe hip pain and gait disturbance. In this report, we show a 35-year-old female with Angel-shaped phalango-epiphyseal dysplasia that was treated by bilateral total hip arthroplasty. She has suffered from her coxalgia since she was 27 and since the age of 30 has been able to walk with the aid of crutches. The radiographs of her bilateral hip showed severe osteochondrotic changes with a progressive disappearance of the joint space. Total hip arthroplasties were performed to treat the osteoarthrosis on the bilateral hip joint due to Angel-shaped phalango-epiphyseal dysplasia. One year after surgery, she is pain-free, and able to walk with a cane. Based on this case, we propose that total hip arthroplasty should be considered one of the treatments for the coxopathy in patients with Angel-shaped phalangoepiphyseal dysplasia.