Bone cysts at the meniscal attachment are associated with a longer symptom duration among patients with arthroscopically treated medial meniscus posterior root tear.

PURPOSE: To elucidate the features of bone cysts at attachment sites of medial meniscus posterior root tears (MMPRTs). METHODS: Knees treated using arthroscopic surgery for MMPRT between 2015 and 2022 were retrospectively reviewed. Patients without a memory of onset (painful popping), prior knee surgeries, concomitant ligament or meniscus injuries or fractures were excluded. Duration from onset to magnetic resonance imaging (MRI) and type of tear were evaluated during arthroscopy. On radiography, meniscus signs (cleft/ghost/giraffe neck), bone cysts at the attachment site of the MMPRT and posterior shiny-corner lesions (PSCLs; bone marrow lesions on the meniscal-covered portion of the posterior tibial plateau) were evaluated. The sensitivity and specificity of the bone cysts were assessed by comparison with matched patients who underwent arthroscopic surgery for medial meniscus posterior horn tear. In addition, subgroups (cyst-positive/cyst-negative) among patients with MMPRT were created to assess the features of bone cysts. RESULTS: A total of 275 patients with MMPRT and 275 matched patients with posterior horn tears were evaluated. The sensitivity and specificity of bone cysts for MMPRT in this study were 22.2% and 98.6%, respectively. Among the 275 knees with MMPRT, compared with the cyst-negative group, the cyst-positive group had a longer duration from onset to MRI (12.9 ± 13.1 vs. 8.3 ± 10.9 weeks, respectively, p = 0.025) and reduced occurrence of PSCLs (18.0% vs. 42.0%, respectively, p = 0.031). CONCLUSION: The occurrence of bone cysts at the attachment site was helpful for the accurate diagnosis of MMPRT and related to longer duration from onset to MRI and reduced PSCLs. LEVEL OF EVIDENCE: Level III, cross-sectional study.

Arthroscopic pullout repair versus suture anchor repair for medial meniscus posterior root tear combined with high tibial osteotomy.

BACKGROUND: The aim of this study was to compare the outcomes of pullout repair with a metal button and suture anchor repair for medial meniscus posterior root tears in patients undergoing high tibial osteotomy with varus alignment. METHODS: Patients who underwent arthroscopic pullout repair (P group) and suture anchor repair (SA group) in combination with open-wedge high tibial osteotomy between 2018 and 2021 were retrospectively examined. Patients who received second-look arthroscopy at 1 year and at least 2 years of follow up were included. Structural healing (complete/partial or failed healing) and chondral lesions at the initial surgery and the second-look arthroscopy, radiographic parameters around the knee, Lysholm score, and Tegner activity scale (before and 2 years after surgery) were compared. RESULTS: A total of 88 patients (68 women/20 men, mean age 61.1 ± 7.9 years old) were included in the analysis. Of these, 51 patients underwent pullout repair, while the other 37 underwent suture anchor repair. The SA group showed a significantly higher rate of complete healing (64.9%) than the P group (21.6%, P < 0.001). The Lysholm score significantly improved after surgery in both treatment groups. At the final follow up, the SA group had a significantly higher Lysholm score (89.6 ± 10.7) than the P group (80.9 ± 17.4, P = 0.011). CONCLUSION: Arthroscopic suture anchor repair had superior healing status and Lysholm Score in comparison with pullout repair with a metal button, as it achieved better tension adjustment. This result is meaningful particularly when medial meniscus root repair and high tibial osteotomy are performed simultaneously.

Insufficient restoration of meniscal extrusion by transtibial pullout repair for medial meniscus posterior root tears.

PURPOSE: The long-term changes in the dynamics of the medial meniscus after transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) are not completely understood. Thus, the aim of this study was to investigate the effects of transtibial pullout repair on MMPRTs and whether the effects would be sustained. METHODS: Nineteen knees with MMPRTs that were treated by trans-tibial pullout repair were enrolled in this study. Medial meniscus extrusion (MME) was measured by ultrasonography during knee extension (no weight-bearing with the knee at 0° extension: NW0°) and 90° flexion (no weight-bearing with the knee at 90° flexion: NW90°) with the patient in the supine position and with full weight-bearing (FW0°) preoperatively and at 3 and 12 months postoperatively. The clinical outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score, Lysholm score, and International Knee Documentation Committee score. RESULTS: The difference in MME with NW0° was not statistically significant between the preoperative (3.4 ± 1.0 mm) and 12-month postoperative (3.7 ± 0.6 mm) time points. The MME with NW90° at 3 (2.1 ± 0.7 mm) and 12 months (2.9 ± 0.6 mm) postoperatively were significantly lower than the preoperative values (3.4 ± 0.8 mm) (P < 0.05). However, the value significantly increased from 3 to 12 months postoperatively (P < 0.05). The MME with FW0° at 12 months postoperatively (4.3 ± 0.6 mm) was significantly larger than that at pre-operatively (3.6 ± 0.9 mm) (P < 0.05). All the patients' clinical conditions were significantly improved at 12 months postoperatively when compared to their preoperative clinical conditions. CONCLUSION: Surgery did not reduce the extrusion in the no weight-bearing and weight-bearing positions at knee extension, and these values increased in the postoperative period. In addition, while the surgery reduced the extrusion in the knee flexion position, the restoration achieved by the surgery was not sustained in the long term. LEVEL OF EVIDENCE: Level IV.

Increased Bone Plug Depth From the Joint Increases Tunnel Enlargement in Anterior Cruciate Ligament Reconstruction Using Bone-Patellar Tendon-Bone Autograft With Suspensory Femoral Fixation.

Purpose: To determine a safe bone plug depth fixation zone based on early tunnel enlargement rates in anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) autograft with suspensory femoral fixation. Methods: Patients who had undergone rectangular tunnel ACL reconstruction using BPTB autograft with suspensory femoral fixation were retrospectively identified. Femoral and tibial tunnel aperture areas were measured on computed tomography 2 weeks and 6 months after surgery to calculate rates of femoral and tibial tunnel enlargement (FTE and TTE), respectively. Femoral bone plug depth (FBPD) and tibial bone plug depth (TBPD) were defined as the distance of the tip of the plug from the respective joint lines. Optimal FBPD and TBPD cutoff values were calculated for the following rates of FTE and TTE, respectively: 0%, 15%, 30%, and 50%. Results: Sixty-four patients (19 females, 45 males; mean age, 29.5 ± 12.3 years) were included in the study. The femoral and tibial tunnel apertures significantly enlarged over time. FBPD (P < .001; r = 0.607) and TBPD (P = .013; r = 0.308) were positively correlated with FTE and TTE, respectively. The optimal FBPD cutoff value was 2.8 mm for FTE rates of 0% and 15%, 3.6 mm for 30%, and 6.0 mm for 50%. The optimal TBPD cutoff value was 1.48 mm for a 0% TTE rate and 5.1 mm for those higher. The cutoff value specificities were lower for the tibial tunnel than the femoral tunnel for each tunnel enlargement rate. Conclusion: Early tunnel enlargement and bone plug depth were significantly correlated in bone the femoral and tibial tunnels. The degree of correlation was higher in the femoral tunnel. To minimize bone tunnel enlargement, the distal end of the femoral bone plug should be placed less than 2.8 mm from the tunnel aperture. Level of Evidence: Level IV, therapeutic case series.

Evaluation of the bone tunnel position and state of healing on second-look arthroscopy after pullout repair of medial meniscus posterior root tear during open-wedge high tibial osteotomy.

BACKGROUND: The aim of the present study was to evaluate the outcome of pullout repair of medial meniscus posterior root tear during open-wedge high tibial osteotomy, including the bone tunnel position and the state of healing on second-look arthroscopy. METHODS: The cohort comprised 22 patients (six men, 16 women) who underwent arthroscopic root fixation by the transtibial pullout technique for medial meniscus posterior root tear during open-wedge high tibial osteotomy. The mean patient age was 63.7 years. The location of the tibial tunnel was assessed using a percentage-dependent method, and the location of a critical point was determined by two coordinates on CT. We defined the distance between the tibial tunnel center and the medial meniscal posterior root anatomic center as the TC-AC distance. The healing state was classified as complete, partial, or failed on second-look arthroscopy. Patients were categorized into those with complete or partial healing (group H) and those with failed healing (group F). The differences in the outcomes and characteristics of groups H and F were evaluated. RESULTS: Twelve and 10 knees were classified into groups H and F, respectively. The bone tunnel position was significantly more posterior in group H than in group F. The TC-AC distance was significantly shorter in group H than in group F. CONCLUSIONS: In pullout repair of medial meniscus posterior root tear during open-wedge high tibial osteotomy, it was considered important to create a bone tunnel position more posterior to increase the healing rate on second-look arthroscopy. LEVEL OF EVIDENCE: Level Ⅳ.

Sagittal Inclination Angle of Graft Is Associated With Knee Stability After Anatomic Anterior Cruciate Ligament Reconstruction.

PURPOSE: To evaluate whether the sagittal inclination angle (SIA) of a graft is associated with postoperative knee stability after anatomic anterior cruciate ligament (ACL) reconstruction. METHODS: All patients who had undergone anatomic ACL reconstruction between April 2014 and September 2015 in addition to volunteers with no history of knee injury were eligible for inclusion in this study. The patients were evaluated by magnetic resonance imaging of the knee in full extension at 1 year after surgery, as were volunteers. The posterior tibial slope (PTS) angle and the SIA of the intact ACL and reconstructed graft were measured relative to each medial and lateral tibial plateau. The patients were examined for knee stability by the side-to-side difference in the anterior tibial translation on stress radiographs at minimum 2-year follow-up. RESULTS: We included 43 patients (26 male, 17 female, mean age 32.8 ± 14.8 years) and 12 volunteers (7 male, 5 female, mean age 28.7 ± 3.1 years) as normal controls. The mean follow-up duration was 29.8 ± 3.6 months. The mean PTS angle and mean SIA in the patients did not significantly differ from those of the intact ACL. The PTS angle in the patients was not significantly correlated with postoperative side-to-side difference in the anterior tibial translation. However, the graft SIA was significantly correlated with the postoperative anterior tibial translation (medial SIA; r = 0.42, P = .005, lateral SIA; r = 0.52, P < .001). CONCLUSIONS: Even if anatomically reconstructed, the graft SIA in reference to the tibial plateau at full knee extension is variable and is associated with postoperative knee stability. The larger graft SIA was correlated with graft laxity after anatomic ACL reconstruction. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Association between postoperative meniscal extrusion and clinical outcomes of the pullout fixation technique for medial meniscus posterior root tear.

OBJECTIVE: To evaluate the correlation between meniscal extrusion in the coronal plane with clinical and radiological outcomes at a minimum of 1 year after transtibial pullout fixation for medial meniscus posterior root tear (MMPRT). METHODS: Data from 30 patients (five males, 25 females) with MMPRT who underwent arthroscopic root fixation by the transtibial pullout technique between 2011 and January 2015 were retrospectively analyzed. The mean patient age was 60.7 ± 8.3years. The median time between injury and surgery was 3.8 months (range, 0.5-15 months). Medial meniscus radial displacement was assessed on magnetic resonance imaging performed preoperatively and at 1 year after fixation. The patients were divided into two groups based on the presence on magnetic resonance imaging of decreased meniscal extrusion (group A) or increased meniscal extrusion (group B) at 1 year postoperatively compared with preoperatively. The two groups were compared regarding factors including age at surgery, sex, body mass index, time between injury and surgery, and the Lysholm score and Kellgren-Lawrence (K-L) grade preoperatively and at 1 year postoperatively. RESULTS: There were seven knees in group A, and 23 in group B. Both groups had a significantly improved Lysholm score postoperatively compared with preoperatively (p < 0.001). Although the postoperative K-L grade was significantly worse than the preoperative K-L grade in group B (p < 0.001), the postoperative K-L grade did not worsen postoperatively in group A. CONCLUSION: The K-L grade did not worsen postoperatively in the group with decreased meniscal extrusion at 1 year after transtibial pullout fixation for MMPRT compared with preoperatively.

A steep coronal graft bending angle is associated with bone tunnel enlargement of the posterolateral bundle after anterior cruciate ligament reconstruction.

PURPOSE: The correlation between the graft bending angle (GBA) of the anteromedial bundle and posterolateral bundle after anterior cruciate ligament reconstruction (ACLR) and postoperative tunnel enlargement was evaluated. METHODS: Two hundred fifty-eight patients (137 males, 121 females; mean age 27.3 years) who had undergone double-bundle ACLR were included. Computed tomographic scans of the operated knee were obtained at 2 weeks and 6 months postoperatively. The area of the tunnel aperture for femoral anteromedial tunnel (FAMT) and femoral posterolateral tunnel (FPLT) was measured; the area at 2 weeks after ACLR was subtracted from the area at 6 months after ACLR and then divided by the area at 2 weeks after ACLR. The femoral tunnel angles were obtained with Cobb angle measurements. The femoral tunnel angle in the coronal plane was measured relative to the tibial plateau (coronal GBA). On the median value, the patients were divided into two groups in each of FAMT and FPLT; those with a coronal GBA of FAMT of ≥27° were classified as group A, while those with a coronal GBA of <27° were classified as group B, those with a coronal GBA of FPLT of ≥23° were classified as group C, while those with a coronal GBA of<23° were classified as group D. RESULTS: Group A included 129 knees, while group B included 129 knees. Groups A and B did not significantly differ regarding FAMT enlargement. Group C included 133 knees, while group D included 125 knees. The percentage of FPLT enlargement in group C was significantly smaller than that in group D (p = 0.001). CONCLUSIONS: A steep coronal GBA of the FPLT after ACLR results in greater FPLT enlargement. The present findings suggest that surgeons should avoid creating a steep GBA of the FPLT in the outside-in technique.

The relationship between the clinical results and the remnant type following anterior cruciate ligament reconstruction using a hamstring tendon.

PURPOSE: The aim of the present study was to investigate the correlations among the preoperative and postoperative knee laxity, the clinical results, and the type of remnant tissue following the anterior cruciate ligament (ACL) reconstruction. METHODS: One hundred ninety-two patients (male, n = 101; female, n = 91; mean age, 27.1 years) with ACL-deficient knees who had undergone double-bundle reconstruction were included. The time between injury and surgery (TBIS) was 34.7 weeks (range, 1-504 weeks). The subjects were divided into four groups according to the Crain's classifications and factors such as the age at surgery, gender, TBIS, side-to-side difference (SSD), Tegner activity score (TAS), and Lysholm score were compared. RESULTS: The percentage of patients with ACL remnant pattern types 1, 2, 3, 4 was 19% (37 knees), 52% (101 knees), 9% (19 knees), and 18% (35 knees), respectively. The TBIS of the patients with Crain type 4 was significantly longer in comparison to the other groups ( p < 0.01). A significant difference was observed in the preoperative SSD of the Crain type 3 and Crain type 4 (6.2 ± 3.4 mm, 9.3 ± 3.6, respectively) groups. The TBIS in patients with Crain type 4 was significantly longer in comparison to the other groups ( p < 0.01). There were no significant differences between the groups in terms of the postoperative SSD, TAS, or Lysholm score. CONCLUSION: This study suggests that a Crain type 3 remnant was associated with a significantly lower preoperative SSD. In addition, the TBIS in patients with Crain type 4 was found to be significantly longer in comparison to the other groups. LEVEL OF EVIDENCE: Level III, case-control study.

Patient age as a preoperative factor associated with tunnel enlargement following double-bundle anterior cruciate ligament reconstruction using hamstring tendon autografts.

PURPOSE: A few studies have detected associations of post-operative tunnel enlargement with sex, age, and the timing of anterior cruciate ligament reconstruction (ACLR). The aim of the present study was to investigate the correlation between post-operative tunnel enlargement following ACLR using hamstring tendon autografts and preoperative factors. The authors hypothesized that tunnel enlargement is associated with age in patients undergoing ACLR. METHODS: One hundred and six patients (male, n = 57; female, n = 49; mean age, 26.9 years) who underwent double-bundle ACL reconstruction were included in the present study. The time between injury and surgery was 26.3 ± 71.4 weeks. Computed tomographic scans of the operated knee were obtained at 2 weeks and 6 months after surgery. The area of the tunnel aperture was measured for the femoral anteromedial tunnel (FAMT), femoral posterolateral tunnel (FPLT), tibial anteromedial tunnel (TAMT), and tibial posterolateral tunnel. The percentage of tunnel area enlargement was defined as the area at 2 weeks after ACLR subtracted from the area at 6 months after ACLR and then divided by the area at 2 weeks after ACLR. Spearman's correlation coefficient was calculated for each factor. The patients were divided into two groups based on age. Patients aged <40 and ≥40 years were assigned to Groups A and B, respectively. The differences in the outcomes and characteristics of the two groups were evaluated. RESULTS: The percentage of enlargement of the FAMT, FPLT, and TAMT was correlated with patient age (r = 0.31, p = 0.001; r = 0.24, p = 0.012; and r = 0.30, p = 0.002, respectively). In total, 87 and 19 knees were classified into Groups A and B, respectively, based on patient age. The percentage of enlargement of the FAMT was significantly higher in Group B than A (78 vs. 60%, respectively; p = 0.01). The percentage of enlargement of the TAMT was significantly higher in Group B than A (53 vs. 36%, respectively; p = 0.03). CONCLUSION: The percentage of enlargement of the FAMT and TAMT was associated with patient age. These findings suggest the need to consider the possibility of tunnel enlargement when double-bundle ACLR is performed for patients aged >40 years. Age was a preoperative factor associated with tunnel enlargement. LEVEL OF EVIDENCE: III.

The remnant preservation technique reduces the amount of bone tunnel enlargement following anterior cruciate ligament reconstruction.

PURPOSE: The aim of the present study was to investigate the correlation between postoperative tunnel enlargement after ACLR and remnant tissue preservation using the hamstring tendon. METHODS: One hundred and ninety-two subjects (male, n = 101; female, n = 91; mean age 27.1) who had undergone double-bundle ACL reconstruction were included in the present study. The patients were divided into two groups: the remnant tissue preservation group (Group R) and the non-remnant tissue preservation group (Group N). Computed tomographic scans of the operated knee were obtained at 2 weeks and 6 months after surgery. The area of the tunnel aperture for the anteromedial femoral tunnel (FAMT), posterolateral femoral tunnel (FPLT), anteromedial tibial tunnel (TAMT), and posterolateral tibial tunnel (TPLT) was measured. The area at 2 weeks after ACLR was subtracted from the area at 6 months after ACLR and then divided by the area at 2 weeks after ACLR. The differences in the outcomes and characteristics of the two groups were evaluated. RESULTS: Seventy-seven knees were classified into Group R, and 115 knees were classified into Group N. The age, gender, and body mass index did not differ to a statistically significant extent. The percentages of FAMT and TAMT enlargement in Group R were significantly smaller in comparison with Group N (P = 0.003 and P = 0.03, respectively). The percentage of FPLT and TPLT enlargement in the two groups did not differ to a statistically significant extent. CONCLUSION: The remnant-preserving technique reduces the amount of bone tunnel enlargement. The present findings indicate the advantages of the remnant-preserving ACLR technique, and therefore the remnant-preserving technique should be recommended. LEVEL OF EVIDENCE: II.

Factors affecting knee laxity following anterior cruciate ligament reconstruction using a hamstring tendon.

BACKGROUND: The aim of the present study was to investigate the correlation between the pre-operative and intraoperative factors that predict postoperative knee laxity following anterior cruciate ligament (ACL) reconstruction using a hamstring tendon. METHODS: The subjects included 108 patients (male, n=49; female, n=59) with ACL-deficient knees who had undergone double-bundle reconstruction. The median time between injury and surgery (TBIS) was 27.5weeks (range one to 504). The patients were divided into two groups according to the side-to-side difference (SSD) in anterior translation on a stress radiograph one year after undergoing the operation (Group A: SSD of <3mm and Group B: SSD of ≥3mm) and were compared regarding such factors as age at surgery, sex, body mass index, pivot shift test, TBIS, pre-operative laxity, concomitant ligament, meniscus, and articular cartilage injury. A logistic regression analysis was performed to identify the factors associated with knee laxity. RESULTS: The postoperative SSD values after one year were correlated with the TBIS (r=0.28; P<0.01). Eighty-one and 27 knees were classified into Groups A and B, respectively, based on the SSD at one year after surgery. The TBIS in Group B (60.2weeks) was significantly longer than that in Group A (16.6weeks; P<0.01). A logistic regression analysis showed that there was a significant association between the TBIS and postoperative knee laxity (P<0.01; odds ratio 1.013; 95% CI 1.002-1.023). CONCLUSION: Increased knee laxity was associated with the time between injury and surgery.

Relationship between knee osteoarthritis and the locomotive syndrome risk tests: A cross-sectional study.

OBJECTIVE: To determine the relationship between locomotive syndrome (LS) risk tests and knee osteoarthritis (KOA). STUDY DESIGN: Cross-sectional cohort study. METHODS: In 2015, 225 people (male 84, females 141, mean age 67.9, range 30-90) were examined using LS risk tests, including the stand-up test, the two-step test, and the 25-question risk assessment, in Katashina Village in Gunma prefecture. The Japanese orthopaedic association defined LS risk test stage 1, difficulty with standing from a 40-cm-high seat using one-leg in the stand-up test, two-step test <1.3, the 25-question risk assessment ≧7, and defined stage 2, difficulty with standing from a 20-cm-high seat using both legs in the stand-up test, two-step test <1.1, the 25-question risk assessment ≧16. Persons with two or more of the following on the ultrasound (US) assessment were defined as having KOA: peripheral joint space (PJS) < 5 mm during weight-bearing; medial radial displacement (MRD) > 5 mm during weight-bearing; and osteophytes > 2 mm. If the residents had KOA in either knee, they were defined as having KOA. RESULTS: 45 residents had KOA in either knee. Logistic regression analysis adjusted for age, height, weight, gender, and knee pain was performed with stage 0 as reference. On the stand-up test, the odds ratio was 5.484 (95% confidence interval (CI) 1.966-15.297) for stage 1 and 2.067 (95% CI 0.426-10.017) for stage 2. On the two-step test, the odds ratio was 1.497 (95% CI 0.557-4.021) for stage 1 and 0.71 (95% CI 0.210-2.395) for stage 2. On the 25-question risk assessment, the odds ratio was 1.73 (95% CI 0.646-4.631) for stage 1 and 1.5 (95% CI 0.508-4.433) for stage 2. CONCLUSIONS: A stand-up test of stage 1 had a significant relationship with KOA. This might suggest that proper care of KOA is needed to prevent progressive disability.

Disruption of DNA Damage-Response by Propyl Gallate and 9-Aminoacridine.

The DNA-damage response (DDR) protects the genome from various types of endogenous and exogenous DNA damage, and can itself be a target of certain chemicals that give rise to chromosomal aberrations. Here, we developed a screening method to detect inhibition of Mediator of DNA damage Checkpoint 1 (MDC1) foci formation (the Enhanced Green Fluorescent Protein (EGFP)-MDC1 foci formation-inhibition assay) using EGFP-MDC1-expressing human cells. The assay identified propyl gallate (PG) and 9-aminoacridine (9-AA) as inhibitors of camptothecin (CPT)-induced MDC1 foci formation. We demonstrated that the inhibition of CPT-induced MDC1 foci formation by PG was caused by the direct suppression of histone H2AX phosphorylation at Ser139 (γH2AX), which is required for MDC1 foci formation, by quantifying γH2AX in cells and in vitro 9-AA also directly suppressed H2AX Ser139-phosphorylation in vitro but the concentration was much higher than that required to suppress CPT-induced MDC1 foci formation in cells. Consistent with these findings, PG and 9-AA both suppressed CPT-induced G2/M cell-cycle arrest and increased the number of abnormal nuclei. Our results suggest that early DDR-inhibitory effects of PG and 9-AA contribute to their chromosome-damaging potential, and that the EGFP-MDC1 foci formation-inhibition assay is useful for detection of and screening for H2AX Ser139-phosphorylation-inhibitory effects of chemicals.

Sonographic evaluation of the medial aspect of the knee in a population-based cohort study.

PURPOSE: The aim of this study was to evaluate the medial aspect of the knee with ultrasound (US). METHODS: This study included 71 men and 154 women (450 knees) with a mean age of 65 years. US was used to evaluate the medial joint space of both knees with and without weight-bearing. In each subject, the medial radial displacement of the medial meniscus, the peripheral joint space, and the number of osteophytes were evaluated. The subjects were stratified by age into five groups: 40-49 years, 50-59 years, 60-69 years, 70-79 years, and 80 years and older, and the US findings in each group were compared. RESULTS: Statistically significant differences were noted between the 60-69 and over-80 age groups in medial radial displacements and peripheral joint spaces (p < 0.01 for both). The number of osteophytes significantly increased after 60 years of age (p < 0.01). CONCLUSIONS: We believe that US is a useful tool for making a simple evaluation of the intra-articular components in population-based studies.

Relation among the knee, sagittal spinal alignment, and the spinal range of motion: Investigation in local medical check-ups using the SpinalMouse.

BACKGROUND: This study was designed as an investigation in a local population to assess the relation between the knee joint and spinal alignment in a population-based study using the SpinalMouse. METHODS: Medical check-ups were conducted for residents of a mountain village in Japan. The study population included 107 men and 157 women (528 knees) with a mean age of 71.1 ± 6.8 years (range, 60-87 years). A questionnaire dealing with any current symptoms involving the knees was administered, and physical examinations dealing with the range of motion (ROM) of knee were conducted. The SpinalMouse was used to measure sagittal spinal alignment and spinal ROM. The parameters considered were thoracic kyphosis angle, lumbar lordosis angle (LLA), sacral inclination angle (SIA), and trunk angle of inclination (INC). The patients were divided into a group with knee flexion contracture (FC group) and a group without knee FC (non-FC group) to conduct a comparative study of both groups. RESULTS: With regard to static spinal alignment, LLA and SIA decreased significantly in the FC group (p < 0.05). With regard to spinal ROM, LLA and INC decreased significantly in the FC group (p < 0.05). CONCLUSION: Results suggested that the knee and the spine affect each other and that the spinal ROM is also involved. The current study may explain the development of knee-spine syndrome.

Population-based study of the relationship between medial meniscus radial displacement, determined by use of ultrasound screening, and knee pain.

PURPOSE: The purpose of this population-based study was to clarify the incidence of knee pain by use of ultrasound (US). METHODS: Medical check-ups were conducted for residents of a mountain village in Japan. The subjects were 149 males and 252 females (802 knees) with a mean age of 63.5 ± 12.5 years. US was used to evaluate the medial joint space of both knees, with and without weight-bearing. For each patient, medial radial displacement of the medial meniscus (MRD) and number of osteophytes were evaluated. A questionnaire was used to determine whether the subjects were currently experiencing knee pain while walking, climbing stairs, or resting that had lasted more than one month. A visual analog scale was used to assess knee pain. The subjects were divided into two groups, those with knee pain (P group) and those without knee pain (non-P group), on the basis of whether a visual analog scale (VAS) was less than or more than 20 mm during walking, climbing stairs, or resting. Logistic regression analysis was used to identify the factors associated with knee pain. RESULTS: Significantly different weight-bearing MRD (WMRD), osteophytes, and pain while walking, climbing stairs, or resting (p < 0.01) were found between the two groups. Logistic regression analysis showed that WMRD was significantly associated with knee pain during walking or while climbing stairs. CONCLUSION: We found that WMRD was significantly associated with knee pain while walking or climbing stairs, which are weight-bearing activities. On the basis of the findings of this study, we believe US is a useful tool for evaluating the factors associated with knee pain in a population-based study. LEVEL OF EVIDENCE: Level III.

Morphological evaluation and diagnosis of medial type osteoarthritis of the knee using ultrasound.

OBJECTIVE: The aim of this study was to diagnose osteoarthritis (OA) of the knee joint using ultrasound (US). METHODS: The study subjects included 27 males and 54 females (131 knees), who had a mean age of 62.8 years. US was used to evaluate the medial joint space of both knees in complete extension with and without weight-bearing. In each patient, the medial radial displacement of the medial meniscus (MRD), the peripheral joint space (PJS) and the number of osteophytes were evaluated. The subjects were divided into five groups based on the KL grade (0-4), and then each value was compared. Additionally, the subjects were divided into two groups: KL grade 0 and 1 (non-OA group) and KL grade 2-4 (OA group). We classified patients who met the following criteria as having OA on the US assessment: <5 mm of PJS during weight-bearing, >5 mm of MRD during weight-bearing, and >2 mm of osteophytes. Then we examined the diagnostic accuracy of the radiographic diagnosis (non-OA or OA of the knee) using US assessment. RESULTS: The PJS was significantly decreased and the MRD was significantly increased in the OA group compared to the non-OA group (p < 0.001). The percentage of radiographic OA of the knee that was correctly diagnosed by ultrasound was 90.8 % (sensitivity), with a specificity of 95.5 %. The positive predictive value was 97.5 % and the negative predictive value was 84.0 %. CONCLUSIONS: Our study therefore showed that US has both a high reliability and excellent diagnostic accuracy.

Influence of the anterior-posterior femoral translation on the range of motion in cruciate-retaining total knee arthroplasty.

PURPOSE: The purpose of this study is to evaluate the post-operative range of motion (ROM) of the knee related to the anterior-posterior femoral translation on the tibia observed during surgery in cruciate-retaining total knee arthroplasty (TKA) using a navigation system. Our hypothesis is that the intraoperative anterior-posterior femoral translation is correlated with the post-operative ROM in patients undergoing cruciate-retaining TKA. METHODS: The subjects were 20 patients involving 23 joints. The passive maximum ROM was measured before and 1 year after surgery. In addition, we evaluated the intraoperative anterior-posterior femoral translation that was measured after inserting a tensor device from 10° to 120° of knee flexion. The starting point of the anterior-posterior femoral translation was defined as when the femur started to move posteriorly. The anterior-posterior femoral translation 120 was set as the amount of femoral movement from 10° to 120°. RESULTS: The subjects were divided into those with an increased or maintained ROM (group A) and those with a decreased ROM (group B). There were no significant differences between the two groups in terms of the age or pre-operative ROM. The starting point of the anterior-posterior femoral translation was significantly earlier in group B (58.0 ± 5.7° for group A, 48.7 ± 3.2° for group B) (P < 0.05). Regarding the anterior-posterior femoral translation 120, Group B showed a larger amount of femoral movement posteriorly than group A (13.0 ± 6.5 mm for group A, 19.0 ± 6.2 mm for group B) (P < 0.05). CONCLUSIONS: The present study shows that intraoperative anterior-posterior femoral translation has a significant correlation with the post-operative ROM in patients undergoing cruciate-retaining TKA. If the starting point of the anterior-posterior femoral translation is early and the anterior-posterior femoral translation 120 is large, there is likely to be a decrease in the post-operative ROM. LEVEL OF EVIDENCE: III.