Varus knee osteoarthritis with ankle osteoarthritis demonstrates greater hindfoot inversion and larger ankle inversion loading during gait following total knee arthroplasty compared to varus knee osteoarthritis alone.

PURPOSE: Although patients with varus knee osteoarthritis (KOA) and concurrent ankle osteoarthritis (AOA) may experience increased ankle joint pain after total knee arthroplasty (TKA), the underlying mechanism remains unclear. This study aimed to investigate the effects of concurrent AOA on ankle and hindfoot alignment, frontal plane ankle and hindfoot biomechanics during gait following TKA and the clinical outcomes. METHODS: Twenty-four patients with varus KOA who underwent TKA were included in this retrospective cohort study. Patients were categorized into two groups: with and without AOA. Radiographic evaluations of lower-limb, ankle and hindfoot alignment, and knee and ankle clinical outcomes were conducted preoperatively and 6 months postoperatively. In addition, gait analyses were performed to investigate knee, ankle and hindfoot kinematics and kinetics. Each data was compared between patients with and without AOA. RESULTS: Concomitant AOA was found in eight ankles. The AOA group exhibited greater postoperative hindfoot varus and increased postoperative ankle pain than the non-AOA group. Gait analysis showed no significant differences in knee varus alignment or tibial tilt after TKA between the groups. However, the AOA group demonstrated significantly greater hindfoot inversion and larger ankle inversion loading. CONCLUSION: One third of patients who underwent TKA had concurrent AOA associated with hindfoot varus. Despite achieving proper coronal knee alignment postoperatively, these patients experienced greater hindfoot and ankle joint inversion load during gait. Surgeons should consider the inability to evert the hindfoot and the possibility of increased ankle joint pain when planning and performing TKA. LEVEL OF EVIDENCE: Level III.

Weight-bearing line at the ankle joint level shifted laterally after total knee arthroplasty for varus knee osteoarthritis: Evaluation of the hip-to-calcaneus line.

BACKGROUND: Few studies have comprehensively examined how alignment beyond the ankle joint changes after Total knee arthroplasty (TKA). This retrospective study aimed to answer the questions: (1) do the radiological parameters beyond the ankle joint, including the weight-bearing line at the ankle joint level, change after TKA in varus knee osteoarthritis? (2) Does the lower extremity alignment correlate with alignment beyond the ankle joint? HYPOTHESIS: Our hypothesis was that TKA altered the radiological parameters beyond the ankle, which correlated with the lower extremity alignment. PATIENTS AND METHODS: This retrospective study included 67 patients who underwent mechanically aligned TKA for varus knee osteoarthritis. The hip-knee-ankle angle (HKA), tibial plafond inclination angle (TPIA), hindfoot alignment angle (HA), talar tilt (TT), and weight-bearing line at the ankle joint level (mechanical ankle joint axis point [MAJAP]) were measured using radiographs taken before and 6 months after TKA; each parameter was compared between the two time points. The correlations between HKA and other parameters were examined preoperatively and postoperatively. RESULTS: The mean HKA, TPIA, HA, TT, and MAJAP changed significantly after TKA from 15.0±6.1̊ to 2.6̊±3.5̊, from 10.8̊±5.7̊ to 4.7̊±3.9̊, from 2.3̊±5.5̊ to -2.5̊±4.5̊, from 0.2̊±1.3̊ to -0.5̊±1.4̊, and from 29.3±23.3 to 54.3±20.6, respectively. Correlations were noted between the preoperative HKA and the preoperative TPIA (r=0.58), HA (r=0.36), and MAJAP (r=-0.59), and between the postoperative HKA and the postoperative TPIA (r=0.54) and MAJAP (r=-0.38). DISCUSSION: TKA for varus knee osteoarthritis altered radiological parameters beyond the ankle, with the weight-bearing line at the ankle joint level passing more laterally. The weight-bearing line at the ankle joint level was correlated with lower extremity alignment both preoperatively and postoperatively. LEVEL OF EVIDENCE: IV; single-centre retrospective observational study.

Joint effusion at 3 months after anterior cruciate ligament reconstruction is associated with reinjury.

PURPOSE: To evaluate whether joint effusion at 3 months after anterior cruciate ligament (ACL) reconstruction is associated with ACL reinjury. METHODS: The medical records of 227 consecutive patients who underwent single-bundle ACL reconstruction between 2015 and 2018 were reviewed in this retrospective single-center study. Demographic data such as sex and age at surgery, as well as data on preinjury Tegner activity scale score, time from injury to surgery, presence of meniscus and cartilage injuries, and the occurrence of ACL reinjury within 2 years, were collected. Joint effusion was defined as grade 3 (range 0-3) according to the ACL Osteoarthritis Score by magnetic resonance imaging at 3 months postoperatively. Multivariate logistic regression analysis was performed to control for potential confounders. RESULTS: A total of 176 patients (mean age 22.5 ± 9.9 years) were included. Among these patients, 18 (10.2%) had ACL reinjury. At the multivariate logistic regression analysis, higher Tegner activity scale (odds ratio [OR] 3.12; 95% confidence interval [CI] 1.61-6.04; p < 0.001) and presence of joint effusion (OR 34.5; 95% CI 6.63-179.7; p < 0.001) increased the odds of ACL reinjury, and older age (OR 0.68; 95% CI 0.51-0.92; p = 0.012) decreased the odds of ACL reinjury. CONCLUSIONS: Joint effusion with a larger fluid volume at 3 months postoperatively was one of the risk factors for ACL reinjury independent of confounders, such as age and activity level. This result suggests the possibility of postoperative intervention for ACL reinjury. LEVEL OF EVIDENCE: III.

Relationship Between Posterior Tibial Slope and Lower Extremity Biomechanics During a Single-Leg Drop Landing Combined With a Cognitive Task in Athletes After ACL Reconstruction.

Background: A steeper posterior tibial slope (PTS) is an important risk factor for anterior cruciate ligament (ACL) reinjury. The PTS may affect lower extremity biomechanics under competition-like conditions for athletes with a reconstructed ACL. Hypothesis: It was hypothesized that the PTS would be associated with lower extremity biomechanics, which may increase ACL strain. Study Design: Descriptive laboratory study. Methods: Included were 10 athletes (mean age, 20.9 ± 1.8 years) who had undergone ACL reconstruction. The authors recorded the 3-dimensional lower extremity biomechanics while participants performed a single-leg drop jump with the Stroop task (dual task). Kinematic and kinetic data were analyzed and compared between the involved and contralateral limbs. The medial and lateral PTSs were measured using magnetic resonance imaging scans of the involved knee. The correlation between the biomechanical data and the PTS in each knee was evaluated. Results: The lateral PTS was significantly correlated with the maximum hip adduction moment (r = 0.64; P < .05) and maximum internal tibial rotation angle (r = 0.71; P < .05) in the involved limb. There were no differences in kinematic and kinetic data between the involved and contralateral limbs. Conclusion: In athletes after ACL reconstruction, the lateral PTS was directly associated with the maximum internal tibial rotation angle during single-leg drop landing with a cognitive task. Clinical Relevance: The findings in this study indicate that a steeper lateral PTS may cause internal rotation of the tibia during landing, which may be associated with reinjury in athletes with a reconstructed ACL.

Radiographic analysis using the hip-to-calcaneus line and its association with lower limb joint kinetics in varus knee osteoarthritis.

BACKGROUND: This study aimed to (1) determine whether the hip to ankle (HA) line or hip to calcaneus (HC) line better reflects knee coronal plane kinetics, (2) to examine whether the HC line reflects ankle coronal plane kinetics, and (3) to evaluate the radiological and biomechanical aspects of ankle in varus knee osteoarthritis (OA). METHODS: Full-length, postero-anterior radiographs (hip-to-calcaneus radiographs) were taken and gait analysis was performed in 21 varus knee OA patients. The %HA where the HA lines pass through the tibial plateau, and the %HC and the mechanical ankle joint axis point (MAJAP), where the HC line passes through the tibial plateau and tibial plafond, respectively, were calculated. Knee adduction angular impulse (KAAI) and ankle inversion angular impulse (AIAI) were collected as kinetic data. Finally, we divided the patients into two groups with and without ankle OA, and compared each parameter between both groups. RESULTS: The %HA and %HC were correlated with KAAI (%HA; r = -0.68, P = 0.001, %HC; r = -0.81, P < 0.001, respectively) and MAJAP was correlated with AIAI (r = -0.55, P = 0.009). MAJAP was significantly smaller, and KAAI and AIAI were significantly larger in the ankle OA group. CONCLUSIONS: Radiographic analysis using the HC line was more strongly correlated to knee joint kinetics than the HA line and was also correlated to ankle joint kinetics. Assessing lower limb alignment using the HC line could be useful to evaluate the knee and ankle joints for varus knee OA.

Characterization of bone remodeling of two different porous types of ß-tricalcium phosphates: a quantitative site-by-site analysis using computed tomography.

This study compared the process of bone remodeling using spherical porous ß-tricalcium phosphate (SPTCP) and unidirectional porous ß-tricalcium phosphate (UDPTCP) by quantitative computed tomography (CT) analysis. We retrospectively analyzed the data of 16 patients (4 men, 12 women; age, 43-78 years) who underwent medial opening wedge high tibial osteotomy (MOWHTO) and were followed up for 1 year postoperatively. Nine patients used SPTCP spacers and seven patients used UDPTCP spacers. CT was performed at 1 week, 6 months, and 1 year postoperatively. CT attenuation values were measured at three sites on the axial slice and sagittal slice, i.e., the superior, center, and inferior sites and the lateral, center, and medial sites for UDPTCP and SPTCP, respectively. CT attenuation values were lower for UDPTCP than for SPTCP in all sites at 6 months and 1 year postoperatively (p < 0.05). CT attenuation values decreased in the superior and inferior sites for UDPTCP (p < 0.05), and CT attenuation values decreased in the lateral site for both SPTCP and UDPTCP (p < 0.05). The process of bone remodeling differed between the two over a short-term follow-up of 1 year postoperatively.

Improving visualization of the articular cartilage of the knee with magnetic resonance imaging under axial traction: a comparative study of different traction weights.

OBJECTIVE: Lesions of the articular cartilage of the knee, especially early grades, are not always accurately detected by magnetic resonance imaging (MRI) because of contact between the articular cartilage surfaces of the femur and the tibia. This study aimed to assess the effects of axial leg traction during knee MRI examination on joint space widening and articular cartilage visualization and evaluate the ideal weight for traction. METHODS: MRI was performed on ten healthy volunteers using a 3-T MRI unit with a 3D dual-echo steady-state gradient-recalled echo sequence. Conventional MRI was performed first, followed by traction MRI. The traction weight increased in the order of 5 kg, 10 kg, and 15 kg. Joint space widths were measured, and articular cartilage visualization was assessed at the medial and lateral tibiofemoral joints. Volunteers were asked to evaluate pain and discomfort using a visual analog scale during each procedure with axial traction to assess the safety of traction MRI. RESULTS: The medial tibiofemoral joint space width significantly increased, and the visualization of the articular cartilage significantly improved by applying traction. The joint space width and the articular cartilage visualization showed no significant differences among traction weights of 5 kg, 10 kg, and 15 kg. Pain and discomfort during traction MRI examination were lowest with a traction weight of 5 kg. CONCLUSION: Traction MRI examination may be useful in evaluating articular cartilage lesions at the medial tibiofemoral joint. A traction weight of 5 kg may be sufficient with minimum pain and discomfort.

A Retrospective Analysis of Clinical Outcome and Predictive Factors for Responders with Knee Osteoarthritis to a Single Injection of Leukocyte-Poor Platelet-Rich Plasma.

Although various platelet-rich plasma (PRP) kits are commercially available, the efficacy of these kits for knee osteoarthritis (KOA) has not been fully investigated. This study aimed to investigate the short-term results of leukocyte-poor PRP (LP-PRP) and the factors that contribute to its efficacy. We retrospectively reviewed 124 patients with KOA who were treated with LP-PRP. White blood cell (WBC) and platelet counts in the whole blood and the LP-PRP were measured. KOA severity was assessed using radiography. Clinical evaluation was performed both prior to injection and after an average of 3.3 weeks after the injection using the Japanese Knee Osteoarthritis Measure (JKOM). Responders were defined based on the JKOM. The contributing factors for responders were examined using a multivariate logistic analysis. The responder rate was 58.1% and the contributing factors for responders were a higher visual analog scale score before injection, WBC count in whole blood, and platelet concentration ratio of LP-PRP. The LP-PRP improved the clinical scores in the short term. Certain patient characteristics before injection and the concentration ratio of LP-PRP may be predictors of its efficacy; these may provide clues for elucidating which components of LP-PRP act on KOA pathologies.

Trapezium Fracture Associated with Thumb Carpometacarpal Joint Dislocation: A Report of Three Cases and Literature Review.

Isolated trapezium fracture in combination with thumb carpometacarpal (CMC) joint dislocation is extremely rare, and no treatment consensus exists. Herein, we report 3 successfully treated cases of isolated trapezium fracture with thumb CMC joint dislocation. While good short-term results have been reported in the literature, the possibility of substantial ligament injuries that can lead to future instability of the thumb CMC joint must be noted. In order to obtain an excellent long-term clinical result, we propose the consideration of the anatomical repair of the CMC joint in terms of both bony and ligamentous structures in cases where instability remains after fracture fixation.