Long-term Follow-up of Hand-degloving Injury Treated by Conventional Methods.

Despite medical advances, degloving injury remains one of the most difficult traumatic injuries to treat. The conventional method for treating degloving injury of the hand is reconstruction with a groin flap. However, few reports have described the mid- or long-term functional and aesthetic outcomes after a hand reconstruction with a groin flap. This case report describes a 68-year-old woman with no specific medical history who presented with a severe degloving injury of the right hand, caused by a roller machine. The area of skin loss was covered with a pedicled groin flap that was separated after 3 weeks. Five years after the reconstruction, she had poor functional and aesthetic outcomes. The Japanese Society for Surgery of the Hand version of the Quick Disabilities of the Arm, Shoulder and Hand score was 57.5; the Hand20 score was 60; and the Michigan Hand Outcomes Questionnaire score was 37.5. The static two-point discrimination of the index and middle fingers was more than 15 mm, and Semmes-Weinstein monofilament examination showed that the sensation thresholds of these fingers were purple and blue. The range of motion was 10-degree angle of extension and 60-degree angle of flexion for the metacarpophalangeal joints of the index and middle fingers. Grip strength was 0.0 kg; pulp pinch strength of the index and middle fingers was 1.1 and 0.8 kg, respectively; and side pinch of the index and middle fingers was 0.1 and 0.7 kg, respectively.

Arterial Stiffness, Assessed Using the Cardio-Ankle Vascular Index, before and 2 Years after Total Knee Arthroplasty in Patients with Knee Osteoarthritis.

Purpose: Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and such comorbidities increase the risk of postoperative complications following total knee arthroplasty (TKA). Arteriosclerosis plays a major role in hemodynamic dysfunction and CVD; however, the postoperative changes in arteriosclerosis following TKA have not been evaluated. Therefore, we assessed the postoperative changes in arteriosclerosis using the cardio-ankle vascular index (CAVI) in patients undergoing TKA, and its relationships with preoperative patient characteristics. Methods: Arteriosclerosis was prospectively evaluated in 119 consecutive patients (140 knees) (15 males (17), 104 females (123); median age 73 years) with knee osteoarthritis who underwent TKA. CAVI was measured before and 2 years after TKA, and the relationships between CAVI and preoperative age, sex, BMI, physical activity status, comorbidities, clinical score, triglyceride concentration, cholesterol concentration, and smoking history were analyzed. Results: CAVI remained stable or improved in 54 joints (39%) and worsened in 86 joints (61%) 2 years post-operation. The median difference between pre- and postoperative CAVI was 0.2 (-0.3, 0.8), and the only preoperative factor associated with this change was preoperative CAVI (r = -0.469, p < 0.001). No other preoperative factor had a significant effect on postoperative arteriosclerosis. Conclusions: The results suggest that patients who undergo TKA subsequently show less severe arteriosclerosis, and the protective effect of TKA on arterial stiffness is greater in those with a higher preoperative CAVI. TKA may be an effective means of reducing the deterioration of arteriosclerosis associated with knee osteoarthritis, at least in the relatively short term.

Characteristics of Preoperative Arteriosclerosis Evaluated by Cardio-Ankle Vascular Index in Patients with Osteoarthritis before Total Knee Arthroplasty.

PURPOSE: Cardiovascular disease (CVD) is a major risk factor for mortality in patients with osteoarthritis, and comorbidities increase postoperative complications after total knee arthroplasty (TKA). Arteriosclerosis plays a main role in hemodynamic dysfunction and CVD; however, arteriosclerosis has not been preoperatively evaluated before TKA using the cardio-ankle vascular index (CAVI). In this study, we evaluated the degree of preoperative arteriosclerosis using the CAVI in patients undergoing TKA, as well as its correlations with several preoperative patient factors. METHODS: Arteriosclerosis was evaluated in 209 consecutive patients (251 knees) with osteoarthritis who underwent TKA at our institution between May 2011 and June 2022. The CAVI was measured in the supine position 1 day before TKA, and the correlations between the CAVI and several clinical factors were analyzed. RESULTS: The CAVI was normal in 62 knees (25%), borderline in 71 knees (28%), and abnormal in 118 knees (47%). Univariate analysis revealed a moderate positive correlation between preoperative CAVI and age (r = 0.451, p < 0.001) and a weak negative correlation between preoperative CAVI and body weight (r = -0.306, p < 0.001) and body mass index (BMI) (r = -0.319, p < 0.001). Multivariate analysis showed that age (ß = 0.349, p < 0.001) and BMI (ß = -0.235, p < 0.001) were significantly correlated with preoperative CAVI. CONCLUSION: Arteriosclerosis should be carefully managed intraoperatively and postoperatively in patients with osteoarthritis undergoing TKA, particularly in older patients and patients with a low BMI.

Patient factors impacting localization of popliteal artery before total knee arthroplasty.

PURPOSE: Intraoperative injury to the popliteal artery (PA) should be avoided during total knee arthroplasty (TKA). This study was performed to clarify the preoperative localization of the PA and the patient factors that impact its localization as a preventive measure. METHODS: Ninety-seven patients (110 knees; 18 men, 79 women) with osteoarthritis who underwent primary TKA were retrospectively reviewed. Preoperative sagittal magnetic resonance imaging was used to measure the distance between the PA and the closest point at three levels: the femoral epicondyle (DPF), the tibial articular surface (DPAS), and the posterior tibial cortex (DPT). All variables are expressed in millimeters as median (interquartile range). RESULTS: The median distance was 10.35 (7.90-12.34) mm for DPF, 6.32 (5.12-8.57) mm for DPAS, and 3.76 (2.28-5.26) mm for DPT. Body height and weight showed weak correlations with DPF (r = 0.324, p < 0.001 and r = 0.207, p = 0.03, respectively). DPF was smaller in women [9.82 (7.64-12.23) mm] than in men [11.27 (10.26-12.75) mm] (p = 0.004). A larger flexion angle and range of motion showed a weak negative correlation with DPT (r = - 0.282, p = 0.003 and r = - 0.236, p = 0.016, respectively). Multiple regression analysis revealed that DPF was related to body height (ß = 0.341, p < 0.001) and that DPT was related to the flexion angle (ß = - 0.264, p = 0.005). CONCLUSIONS: Special attention should be paid to women with a small physique on the femoral side and/or patients with a large flexion angle on the tibial side as a strategy to prevent PA-related complications.

Positive effect of total knee arthroplasty on progression of arteriosclerosis evaluated by cardio-ankle vascular index.

INTRODUCTION: Physical function is expected to improve with an increase in physical activity owing to improvement in knee joint pain after total knee arthroplasty (TKA). This study was performed to evaluate the impact of TKA on arteriosclerosis by measuring the cardio-ankle vascular index (CAVI) before and after surgery. MATERIALS AND METHODS: In total, 206 consecutive patients undergoing unilateral TKA were investigated. The CAVI, an index of the overall stiffness of the artery from the origin of the aorta to the ankle, was used to evaluate the degree of arteriosclerosis. The CAVI of the TKA side and non-TKA side was compared before and 1 year after TKA. RESULTS: There were no differences in the CAVI before and after TKA on the TKA side and non-TKA side, although these values should have worsened at 1 year compared with preoperative values. The CAVI, which did not differ between the two sides preoperatively, differed significantly between the two sides postoperatively (p = 0.013). A generalized linear model showed no interaction between each time point and the measured sides in terms of the CAVI. The relationship between the preoperative CAVI and the difference between the preoperative and postoperative CAVI were examined, showing that R = - 0.428 (p < 0.001) for the TKA side and R = - 0.416 (p < 0.001) for the non-TKA side (significant negative correlation). CONCLUSIONS: The lack of significant age-related deterioration over time on both sides suggests that TKA may slow the progression of arteriosclerosis, especially on the operated side. The effect of TKA was found to be greater with a higher CAVI (i.e., more advanced arteriosclerosis).

Comparison of the Tibial Posterior Slope Angle Between the Tibial Mechanical Axis and Various Diaphyseal Tibial Axes After Total Knee Arthroplasty.

Background: The posterior tibial slope angle (PTS) is crucial for sagittal alignment after total knee arthroplasty (TKA). This study aimed to determine which PTS based on the lateral view of standard knee radiographs (LSKRs; 36 × 43 cm) reflects the PTS based on a full-length lateral tibial radiograph (FLTR). Methods: A total of 290 patients (355 knees) who underwent primary TKA were retrospectively recruited. Cross-sectional views from the 3-dimensional digital model of the tibial prosthesis and bone complex in the sagittal plane were used as FLTRs and LSKRs. Considering the region 21.5 cm proximal to the site of FLTR as the spot for LSKR to determine the 5 tibial diaphyseal axes, the axis that simulates the PTS as determined by the tibial mechanical axis between the center of the tibial component and the ankle plafond in LSKR was determined and compared. Results: PTS (α5) defined by the line connecting the midpoints of tibial width between the region 10-cm distal to the knee joint and the distal end of the tibia based on LSKR revealed the least mean difference (0.13° ± 1.00°) and the strongest correlation (P < .001, r = 0.948) with PTS based on FLTR (α0). The number of knees in α5, indicating a difference of <2° from α0, was 333 of 355 (93.8%). The equivalence test results indicated that α0 and α5 were statistically equivalent within a difference of 2° (P < .001). Conclusions: PTS (α5) can be used as a clinically reliable substitution of the true PTS on an FLTR for evaluating sagittal alignment after TKA.

Comparison of Operative Times in Primary Bilateral Total Knee Arthroplasty Performed by a Single Surgeon.

Purpose: Prolonged operative time (OT) is associated with adverse complications after total knee arthroplasty (TKA). The purpose of this study was to determine whether preoperative factors, such as sex, age, body mass index, body weight (BW), body height, American Society of Anesthesiologists grade, tibiofemoral angle, hospital for special surgery scores, surgical side, surgical order, and calendar year of surgery, affect OT. Methods: One hundred and nineteen patients (238 knees) with osteoarthritis who underwent staged bilateral primary TKA performed by a single surgeon were evaluated. The medical records of 15 males and 104 females were retrospectively reviewed. All variables were expressed as median (interquartile range). Results: The OT for all TKAs was 57 min (51, 65). The OT on the left side (59 min (52−67)) was longer than that on the right side (55 min (50−62)) (p = 0.015). Multiple regression analysis revealed that longer OT was related to BW (ß = 0.488, p < 0.001), calendar year of surgery (ß = −0.218, p< 0.001), and operative side (ß = −0.151, p = 0.007). The Jonckheere−Terpstra test showed a trend toward decreasing OT with calendar year on the left side (p = 0.037) (surgeon's non-dominant side), but not on the right (p = 0.795). Body height, BW, and body mass index showed weak correlations (r = 0.212, p = 0.001; r = 0.352, p < 0.001; r = 0.290, p < 0.001, respectively) with OT. Conclusion: Patients with a large physique, and especially obesity, with an affected knee on the surgeon's non-dominant side may require a longer OT; OT decreased over time.

Preoperative bone assessment by bone mineral density and bone turnover in patients undergoing total knee arthroplasty.

BACKGROUND: The preoperative overall bone quality in patients undergoing total knee arthroplasty (TKA) might influence the development of postoperative bone-derived complications. This study was performed to simultaneously evaluate the baseline bone mineral density (BMD) and bone turnover in these patients. METHODS: We prospectively measured the lumbar spine, total hip, and femoral neck BMD using dual-energy X-ray absorptiometry (DXA) in 214 patients (239 knees; women, 199 knees; men, 40 knees) 1 day preoperatively. Women were stratified into three age groups: <70 years (60s), <80 years (70s), and ≥80 years (80s). We assessed bone turnover using the urinary level of N-telopeptide (NTx) normalized to creatinine (NTx/Cre). RESULTS: The prevalence of osteoporosis as assessed by DXA (T-score of ≤ -2.5) was 22% in women and 5% in men. A decline in BMD with aging was found in the hip but not in the lumbar spine with significant differences among ages. Women showed a higher NTx/Cre level than men (p = 0.033). An NTx/Cre level suggesting a high fracture risk (>56.5 mmol BCE/mmol Cre) was present in 54% of women and 35% of men (p = 0.037). No significant differences were found in this prevalence among age groups in women. Seventeen percent of women and 0% of men had both osteoporosis and a high fracture risk simultaneously (p = 0.002). The proportion of women in this category was lower in the 60s than 70s age group (p = 0.019). CONCLUSIONS: Preoperative bone health screening before TKA might be necessary for women aged ≥70 years to prevent complications caused by perioperative poor bone condition.

Preoperative characteristics and intraoperative factors do not correlate with accomplishments of active straight-leg raising, standing up, and walking after primary total knee arthroplasty.

BACKGROUND: The correlations between patient characteristics and early postoperative functional performances after total knee arthroplasty have not been adequately studied. The purpose of this study was to clarify the effects of preoperative characteristics (sex, age, body mass index, American Society of Anesthesiologists grade, hospital for special surgery score) and intraoperative factors (duration of surgery and tourniquet use) on the time required to accomplish active straight-leg-raising, standing up, and walking as the objective performances for the initiation of early postoperative rehabilitation. METHODS: This cross-sectional retrospective study included 307 patients (384 primary total knee arthroplasties). Postoperative times required until each activity was accomplished were measured. Various preoperative characteristics and intraoperative factors that might affect three objective performances were evaluated. RESULTS: The postoperative times required before each activity was accomplished were 1.5 ± 0.5 days for active straight-leg-raising, 1.2 ± 0.5 days for standing up, and 1.4 ± 0.7 days for walking. There were no significant correlations between any factor (age, body mass index, hospital for special surgery score, duration of surgery, and tourniquet use) and the three objective performances using Spearman's correlation coefficient. There were no differences in sex or American Society of Anesthesiologists grade for three objective functional assessments by Wilcoxon rank sum test. CONCLUSIONS: Differences in patient preoperative characteristics and intraoperative factors are unlikely to affect three objective functional performances in the early postoperative period. Therefore, there is no need to consider differences between patients when initiating early postoperative rehabilitation.

Alignment evaluation using different distal reference points after total knee arthroplasty.

BACKGROUND: To assess alignment for total knee arthroplasty, the center of the ankle has been used as the main reference point for the distal tibia; however, the true load-bearing mechanical axis should be determined as a line from the center of the femoral head to the lowest point of calcaneus. Thus, the purpose of this study was to compare the differences in alignment. METHODS: Patients with medial osteoarthritis who underwent primary total knee arthroplasty (Group A, center of ankle reference, or Group C, calcaneal contact reference) were recruited. We determined (1) the total number with calcaneal contact point lateral to the center of ankle and compared (2) percentage of displacement of the load-bearing axis at the level of the knee, (3) anatomical axis angle, (4) mechanical axis angle, and (5) tibial component angle. RESULTS: The study included 94 patients (128 knees), with the calcaneal contact reference point located lateral relative to the center of the ankle in 88.3% (113/128 knees). Using calcaneal contact point references, displacement of the load-bearing axis at the knee was greater (p < 0.0001, 38.7% vs 34.0%), and angles demonstrated significantly valgus alignment (p < 0.0001, 5.6° vs. 4.8° for anatomical axis angle, -3.0° vs. -4.2° for mechanical axis angle, and 89.9° vs. 88.6°for tibial component angle). CONCLUSIONS: Varus alignment measured by the ankle reference method might correspond to the neutral alignment by the amount of valgus alignment indicated by the calcaneal reference. Surgeons should take this into account when preoperative planning, performing intraoperative procedures, and during postoperative evaluation.

Characteristics of hidden blood loss following hybrid total knee arthroplasty.

BACKGROUND: Hidden blood loss (HBL) unrecognized by the usual practice of assessing intraoperative loss and postoperative drainage comprises a considerable proportion of total blood loss (TBL) during primary total knee arthroplasty (TKA). However, HBL has not been adequately investigated in hybrid TKA (uncemented femur, cemented tibia). The purpose of this study was to clarify the amount and influential factors of HBL in hybrid TKA. METHODS: A consecutive series of 151 knees in 137 patients with knee osteoarthritis who underwent hybrid TKA were retrospectively evaluated. We examined the correlations between HBL and various factors of concern for their effects on TBL, including age, sex, body weight (BW), body height, body mass index, operation time, tourniquet time, and visible blood loss (VBL) in three periods (intraoperative: VBL1; until 3 h postoperatively: VBL2; from 3 h to 1 day postoperatively: VBL3). RESULTS: Median (interquartile range) HBL and TBL were 528 (388, 711) mL and 725 (582, 926) mL, respectively. HBL relative to TBL (H/T) was 73%. There were weak correlations between HBL and BW (r = 0.249, p = 0.002) and between HBL and VBL3 (r = -0.261, p = 0.001). Multivariate analyses confirmed a positive correlation between HBL and BW (ß = 0.296, p < 0.001) and a negative correlation between HBL and VBL3 (ß = -0.270, p < 0.001). CONCLUSIONS: Hybrid TKA showed comparable values of HBL and H/T to those reported for cemented TKA. Therefore, management strategies for HBL in hybrid TKA can follow the same protocols used for cemented TKA. High BW and low VBL3 may be predictors of postoperative HBL in hybrid TKA.

Reference Values and Correlations for Multiple Physical Performance Measures: A Cross-Sectional Study among Independently Mobile Older Men in Japan.

PURPOSE: Japan is one of few countries with a male life expectancy over 80 years. The gap between the healthy life span and the total life expectancy is large, highlighting the importance of maintaining physical performance. The present study aims to establish reference values for multiple physical performance measures among high-functioning oldest-old Japanese men and to investigate the correlations among these measurements to understand how these variables are related. METHODS: This study was conducted with 120 Japanese males aged 80 years or older who were able to walk independently. Seven measures of physical performance were assessed: handgrip strength, quadriceps strength, static balance ability (one-legged stance), dynamic balance ability (Functional Reach Test; FRT), walking ability (5-m walking time test), combined movement ability (Timed Up & Go test), and bone quality. Cognitive function was also measured (Mini-Mental State Examination; MMSE). RESULTS: Specific reference values are reported for each physical performance measurement explored in this study. Only six participants were classified as cognitively impaired, and 16 had mild cognitive impairment. There were significant correlations of varying levels among all of the measures of physical performance. Age was significantly correlated with all performance measures except FRT, and there was no correlation between age and MMSE. MMSE was weakly correlated with FRT and unrelated to the other performance measures. CONCLUSIONS: The reference ranges can be used by older men who have not yet reached 80 years and their health care providers as physical performance targets to facilitate the maintenance of independent mobility in later life.

Association of knee osteoarthritis grade with one-leg standing balance and quadriceps strength in male independent ambulators aged ≥80 years.

BACKGROUND: One-leg standing (OLS) balance is an important predictor of falls in people of advanced age. In this population, muscle weakness and knee osteoarthritis also contribute to falls and resultant fractures and thereby affect mortality rates. The Kellgren-Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. This study was performed to evaluate OLS balance and the quadriceps strength (QS) for each KL grade and to clarify the impact of the knee osteoarthritis grade on OLS balance and QS. HYPOTHESIS: OLS balance shows results compatible with those of previous reports when independent walking is possible because of maintenance of QS regardless of the OA grade. METHODS: This single-center prospective cross-sectional study included data on 106 male orthopedic patients (106 knees) aged ≥80 years who could walk independently. OLS balance with eyes open was assessed using the patient's preferred leg. A handheld dynamometer was used to measure QS. The ratio of muscle strength to body weight (QS/BW ratio) was used to evaluate outcomes. Weight-bearing standing knee radiographs were evaluated using the KL classification. OLS balance and the QS/BW ratio were evaluated for each KL grade, and the correlations of the KL grade with OLS balance and the QS/BW ratio were assessed simultaneously. RESULTS: For each KL grade, the number of participants (n), median OLS balance (seconds), and QS/BW ratio (N/kg) were as follows: grade I: 24, 12, and 4.9; grade II: 51, 14, and 5.2; grade III: 22, 14, and 4.9; and grade IV: 9, 26, and 5.7, respectively. There were no significant differences in either OLS balance or the QS/BW ratio among the four grades. CONCLUSIONS: Participants exhibited good OLS balance and QS/BW ratio regardless of their KL grade. This study demonstrated an absence of correlations of the KL grade with OLS balance and the QS/BW ratio, as was previously reported for the KL grade and pain. LEVEL OF EVIDENCE: Level II prospective study.

Knee Osteoarthritis Grade does not Correlate with Quadriceps Muscle Strength or Bone Properties of the Calcaneus in Men Aged 80 Years or More who Can Walk independently.

Purpose: Muscle weakness and bone deterioration in the elderly are related to falls and fractures, resulting in decreased mobility. Knee osteoarthritis also may contribute to falls and fractures and thereby affect mortality rates. The Kellgren-Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. Aims: This study aimed to evaluate the quadriceps strength and bone properties of the calcaneus for each KL grade, and to clarify the impact of knee osteoarthritis grade on quadriceps strength and bone properties. Methods: This prospective cross-sectional study included data on 108 male patients (213 knees), aged ≥80 years, who could walk independently. A handheld dynamometer was used to measure quadriceps strength. Bone properties were evaluated using broadband ultrasound attenuation with a portable bone densitometer. Weight-bearing standing knee radiographs were evaluated using KL classification. Quadriceps strength and bone properties were evaluated for each KL grade and the correlations between the grade and quadriceps strength and bone properties were assessed simultaneously. Results: The numbers of participants in KL grades I-IV were 46, 102, 45, and 20, respectively. There were no differences among grades for either quadriceps strength or bone properties. Conclusions: Participants exhibited good quadriceps strength and bone properties regardless of their KL grade. Relatively high mechanical loading of muscle and bone incurred while walking independently, likely explaining this result. Clinically, this study demonstrated the absence of correlations between KL grade and quadriceps strength and bone properties, as was previously reported in studies showing the absence of a correlation between KL grade and pain.

Predictive factors for longer operative times in patients with medial knee osteoarthritis undergoing total knee arthroplasty.

BACKGROUND: Prolonged operative time has frequently been implicated as a risk factor for various complications after total knee arthroplasty (TKA). We aimed to determine whether preoperative factors such as sex, age, body mass index (BMI), prosthetic design, tibiofemoral angle (TFA), range of motion, coronal laxity, Hospital for Special Surgery score and periarticular bone mineral density (BMD) affect operative time. METHODS: We evaluated 164 patients (187 knees) with medial osteoarthritis who underwent primary TKA performed by a single surgeon. The medical records of 27 males and 137 females (median age of 77 and 72 years, respectively) were retrospectively reviewed. TFA was measured on non-weightbearing, standard radiographs. We used dual-energy X-ray absorptiometry to measure BMD, and an arthrometer to evaluate total coronal laxity in each patient. RESULTS: According to univariate analyses, there was a weak positive correlation between BMI and operative time (r = 0.265, p < 0.001), between TFA and operative time (r = 0.235, p = 0.001) and between BMD of the femur and tibia and operative time (r = 0.280, p < 0.001, r = 0.286, p < 0.001, respectively). No significant correlations were found between the other factors and operative time. Based on multivariate analyses, only BMD of the tibia and TFA were significantly correlated with operative time (ß = 0.418, p < 0.001 and ß = 0.182, p = 0.007, respectively). CONCLUSIONS: TFA and BMD of the tibia were the variables more strongly correlated with operative time. Surgeons should recognize preoperatively that patients who have increased TFA, higher periarticular BMD, and higher BMI may have longer operative times. LEVEL OF EVIDENCE: Level IV retrospective study.

Size of Medial Knee Osteophytes Correlates With Knee Alignment But Not With Coronal Laxity in Patients With Medial Knee Osteoarthritis.

The severity of osteoarthritis (OA) has been related to osteophyte size. However, the effects on osteophyte size of repeated and increased loading associated with joint laxity and varus misalignment remain unclear. We investigated these relationships in patients with medial knee OA and compared the performances of computed tomography (CT) and radiography for assessing osteophyte parameters. We examined knee joint alignment on radiographs and knee laxity using arthrometry in 191 patients with medial knee OA who were undergoing total knee arthroplasty. We also measured femur and tibia osteophyte distance (largest perpendicular distance from the cortical line to outer margin of the osteophyte) using radiography and CT, osteophyte areas (largest area surrounded by the outer margin of an osteophyte) by CT and determined the locations of the osteophytes in the femur and tibia by CT. We then analyzed the correlations between the variables using Spearman's rank correlation tests. Osteophyte sizes in the femur and tibia as determined by radiography (distance) or CT (distance and area) were positively correlated with the degree of varus alignment but not with medial or lateral laxity. There was also a significant correlation between maximum osteophyte distances measured by radiography and CT. The greatest number and the largest osteophytes were located in the posterior third of the femur and middle third of the tibia, respectively. Osteophyte size was correlated with preoperative knee alignment but not with knee laxity in patients with medial knee OA. Osteophyte size can be evaluated using conventional radiography, without the need for CT. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:639-644, 2020.

Mobile-bearing total knee arthroplasty implants combined with surface cementation produced satisfactory clinical and radiographic outcomes at the 5-year follow-up.

PURPOSE: Very little is known about the use of combined surface cementation (only tibial tray) and mobile-bearing tibial components in total knee arthroplasty (TKA). This study was investigated whether the index combinations show satisfactory clinical outcomes after mobile-bearing TKA using posterior cruciate ligament (PCL)-retaining meniscal-bearing (MB) and PCL-substituting rotating-platform (RP) TKA designed using different anteroposterior constraints. METHODS: This study is a retrospective evaluation of a prospective database. Five-year postoperative clinical outcomes were assessed in 127 patients (127 knees) and 122 patients (122 knees) who underwent TKA with an MB and RP design, respectively. The Hospital for Special Surgery (HSS) score, range of motion, loosening/radiolucency, and subsidence around both components were evaluated in the two designs. RESULTS: The postoperative median HSS score was excellent in both the MB and RP groups (93 and 92, respectively). Postoperative flexion and extension did not differ between the two designs. Neither design showed > 2-mm radiolucencies raising concern for femoral or tibial implant stability. Five (2%) of 249 patients (5 knees) (MB, n = 4; RP, n = 1) showed detectable subsidence of the tibial component. However, no revision TKA had been performed by the 5-year follow-up because no patients had complaints severe enough to necessitate revision surgery. CONCLUSIONS: Clinically good outcomes comparable with previous studies were obtained 5 years after mobile-bearing TKA with surface cementation using both MB and RP implant designs. Thus, equivalent mid-term clinical outcomes of the index combination can be obtained with other implant designs and cementation techniques. LEVEL OF EVIDENCE: Level II.

Mediolateral coronal laxity does not correlate with knee range of motion after total knee arthroplasty.

INTRODUCTION: It remains controversial whether coronal laxity after total knee arthroplasty (TKA) is a critical factor in determining clinical outcomes such as knee range of motion (ROM). The purpose of this study was to evaluate the correlation between postoperative ROM and coronal laxity, which was defined as the angular motion from the neutral, unloaded position to the loaded position, in patients with medial knee osteoarthritis undergoing TKA. MATERIALS AND METHODS: Preoperative and 1-year postoperative coronal laxity were assessed using radiographs by applying a force of 150 N with an arthrometer. A consecutive series of 204 knees was examined. A knee was defined as clinically "balanced" when the difference between medial and lateral laxity was 3° or less. Active ROM was measured using a goniometer. Values were expressed as median values. RESULTS: The ROM was 105° preoperatively and 110° postoperatively, with the correlation being weak (r = 0.372, p < 0.001) between the periods. The total laxity also revealed a weak correlation (r = 0.270, p < 0.001) between the periods. Preoperative laxity was significantly larger (4° vs. 3°) on the medial side (p < 0.001) and postoperative laxity was larger (4° vs. 3°) laterally (p = 0.001). There was no significant correlation between postoperative ROM and laxity pre- and postoperatively. Additionally, there were no differences in ROM between the balanced and unbalanced groups in the pre- and postoperative periods. CONCLUSIONS: This study indicated that mediolateral coronal laxity in patients with an osteoarthritic knee did not correlate with knee ROM after TKA when 3°-4° of laxity in the medial and lateral orientations was maintained.

Association between bone mineral density distribution and various radiographic parameters in patients with advanced medial osteoarthritis of the knee.

PURPOSE: Patients with severe osteoarthritis (OA) of the knee have changes in bone mineral density (BMD) of the distal femur and proximal tibia. Correlations between the medial-to-lateral BMD (M/L-BMD) ratio (which normalizes the potentially confounding effects of body size and sex on BMD) and radiographic parameters that indicate OA progression have not been adequately studied. The purpose of this study was to evaluate correlations between radiographic indicators of OA progression and femoral and tibial M/L-BMD ratios. METHODS: A consecutive series of 182 knees in 156 patients with advanced medial knee OA who underwent total knee arthroplasty were included. We evaluated correlations between the femoral and tibial M/L-BMD ratios and various radiographic parameters, including tibiofemoral angle (TFA), mechanical axis angle (MAA), tibial coronal angle, tibiofemoral subluxation (%), load-bearing axis deviation at the tibial plateau (%), and medial and lateral laxity. RESULTS: Univariate analyses using Spearman's correlation coefficient revealed significant positive correlations between femoral and tibial M/L-BMD ratios and both TFA and MAA and negative correlations with tibial coronal angle and load-bearing axis deviation. Multivariate analyses showed significant associations between TFA and the femoral M/L-BMD ratio (ß = 0.434, p < 0.001) and between MAA and the tibial M/L-BMD ratio (ß = 0.384, p < 0.001). CONCLUSION: BMD distribution around the knee might be predictable with radiographic parameters such as the TFA for the femur and MAA for the tibia. The findings of this study provide in vivo data on the evaluation of preoperative femoral and tibial M/L-BMD ratios without dual-energy X-ray absorptiometry.

Insall-Salvati ratio stabilizes one year after mobile-bearing total knee arthroplasty and does not correlate with mid-to-long-term clinical outcomes.

PURPOSE: It has not been established whether changes in the length of the patellar tendon (LPT) after total knee arthroplasty (TKA) affect clinical outcomes. Therefore, this prospective cohort study aimed to evaluate changes in the LPT over time postoperatively and clarify their impact on clinical outcomes after bilateral TKA, performed with differently designed mobile-bearing (meniscal-bearing and rotating-platform) implants on contralateral knees. METHODS: 51 patients who required staged bilateral mobile-bearing TKA were recruited. LPT was evaluated by measuring the Insall-Salvati ratio (ISR) preoperatively and at 1 week, 6 months, and 1, 2, and ≥ 5 years postoperatively. Hospital for Special Surgery score and range of motion were assessed at the final follow-up. RESULTS: Based on the ISR, there were no differences in the patterns of change between the two types of implant (n.s.). At the 6-month follow-up, the ISRs of both implants had significantly decreased (p = 0.002). Throughout the follow-up, the ISR was significantly lower (p < 0.001) for the meniscal-bearing knees than for the rotating-platform knees. After the 1-year follow-up, there were no further substantial changes in the ISR in either group. There was also no significant correlation between the ISR and clinical outcomes. CONCLUSIONS: LPT decreased after both mobile-bearing TKAs for up to 1 year postoperatively, although the decrease was more significant for the meniscal-bearing knees than the rotating-platform knees. After 1 year postoperatively, however, these conditions had stabilized, with no further changes. Thus, LPT plays a minimal role in mid-to-long-term clinical outcomes after TKA. LEVEL OF EVIDENCE: Therapeutic prospective study, Level II.