Midterm Clinical and Radiological Outcomes of Revision Lateral Meniscal Allograft Transplantation.

Background: It is unknown whether the outcomes achieved in the early period after revision lateral meniscal allograft transplantation (RLMAT) are maintained through the midterm period. Purpose: To evaluate the midterm clinical and radiological results of patients who underwent RLMAT. Study Design: Case series; Level of evidence, 4. Methods: We reviewed the outcomes of 19 RLMATs in 18 patients with at least 5 years of follow-up data. The mean follow-up period was 6 ± 1.1 years (range, 5-8.5 years). Clinical outcomes were assessed using the modified Lysholm score, the International Knee Documentation Committee (IKDC) subjective score, and the Tegner activity level. Radiographic progression of arthritis was measured by the absolute and relative joint space widths on 45° of knee flexion posteroanterior radiographs preoperatively, 1 year postoperatively, and at the latest follow-up.Failure was defined as meniscocapsular separation, removal, or tear of more than half of the meniscal allograft on postoperative magnetic resonance imaging (MRI) or conversion to total knee arthroplasty. Of the 18 patients, 3 underwent ≥2 RLMATs. The survival rate was evaluated according to the number of revision surgeries. Results: For knees with an intact meniscus transplant at the final follow-up, the modified Lysholm and IKDC scores were significantly improved compared with preoperatively, but the Tegner activity level was unchanged. No significant differences were found in the absolute and relative joint space widths postoperatively. There were 6 failures within 3 years after RLMAT; the overall 5-year survival rate was 68.4% (13/19 knees). All failed knees showed bucket-handle tear patterns on MRI due to meniscocapsular healing failure. The survival rate decreased as the number of RLMATs increased-73.3% for a first RLMAT (n = 15 knees), 66.7% for a second RLMAT (n = 3 knees), and 0% for a third RLMAT (n = 1 knee). Midterm MRIs of 8 well-healed RLMATs showed evidence of meniscal degeneration; nonetheless, this did not affect clinical outcomes. Conclusion: The midterm results of RLMATs demonstrated a 5-year survival rate of 68.4% and positive clinical and radiological outcomes for failed MATs despite unimproved activity levels. Inadequate meniscocapsular healing was the leading cause of failure, and it needs to be carefully considered when performing RLMATs.

Risk Factor for Clinical Failure of Medial Meniscal Allograft Transplant: Early vs Late Graft Tear.

BACKGROUND: Graft tears are common postoperative findings in meniscal allograft transplant (MAT). Graft tear in medial MAT may be different from that of lateral MAT, considering the difference between medial meniscal tears and lateral meniscal tears. Moreover, medial MAT is frequently accompanied by ligament reconstruction, which is associated with graft tear. The effect of graft tear on the long-term survivorship of medial MAT has not been investigated. HYPOTHESIS: Graft tear would adversely affect the survivorship of medial MAT and the effect would be different according to the timing of graft tear. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 55 patients undergoing medial MAT between June 2019 and March 2000 were retrospectively reviewed. Postoperative magnetic resonance imaging (MRI) scans were reviewed to identify graft tears, and the timing of their occurrence was investigated. Postoperative MRI was performed routinely during the first postoperative year and every 2 years thereafter. The patients were classified into a no graft tear (NT) group, early graft tear (occurring within 1 year; ET) group, and late graft tear (occurring 1 year after surgery; LT) group. The survival rate of medial MAT was estimated according to graft tear, with a failure being defined as (1) reoperations including arthroplasty, realignment osteotomy, revision MAT, and meniscectomy (>50% of the graft or to the zone of the meniscocapsular junction) or (2) Lysholm score <65. Clinical scores were compared between the groups. RESULTS: The mean follow-up duration was 8.6 ± 5.3 years. During that period, clinical failures occurred in 6 (10.9%) patients. The overall survival rate at 5 years was 94.0% (95% CI, 90.6%-97.4%). Graft tears were seen in 18 patients: 6 patients in the ET group and 12 patients in the LT group. The median time when the graft tear was noted on MRI scans was 5.5 months (range, 1-11 months) postoperatively in the ET group and 99.5 months (range, 19-264 months) postoperatively in the LT group. Five patients in the ET group had root tears, whereas 9 patients in the LT group had complex or horizontal tears. The 5-year survival rate of the ET group was 62.5% (95% CI, 41.2%-83.8%), which was significantly lower than that of the NT group (96.8%; 95% CI, 93.6%-99.9%) and the LT group (85.7%; 95% CI, 72.5%-98.9%; P = .002). The mean postoperative Lysholm scores were 85.6 ± 17.9 in the NT group, 93.0 ± 2.8 in the ET group, and 79.3 ± 11.6 in the LT group, showing no significant difference between the groups (Kruskal-Wallis test, P = .058). CONCLUSION: Clinical relevance of graft tear that occurred after medial MAT was dependent upon its timing. ET was a risk factor for clinical failure, whereas LT did not adversely affect graft survivorship. Lysholm scores did not differ according to graft tear.

Early Graft Tear As a Major Risk Factor for the Clinical Failure of Lateral Meniscal Allograft Transplantation.

BACKGROUND: Graft tears are often observed on magnetic resonance imaging after lateral meniscal allograft transplantation (MAT). Their characteristics, such as the location and configuration, are likely to be different depending on the timing of the injury. However, the clinical relevance of early and late graft tears has not been investigated. HYPOTHESIS: (1) Both early and late graft tears would be associated with the clinical failure of lateral MAT, and (2) an early graft tear (ET) would lead to worse outcomes than a late graft tear (LT) or an intact graft. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 261 patients who had undergone lateral MAT between March 2000 and June 2019 were retrospectively reviewed. The graft tear was investigated using magnetic resonance imaging, which was performed routinely during the first postoperative year and every 2 years thereafter. The patients were classified according to the timing of the graft tear: no graft tear (NT) group, ET (≤1 year after surgery) group, and LT (>1 year after surgery) group. Clinical failure was defined as (1) reoperations including arthroplasty, realignment osteotomy, revision MAT, and meniscectomy (>50% of the graft or to the zone of the meniscocapsular junction) or (2) a Lysholm score of <65. Risk factors for a low survival rate were investigated using Cox regression analysis. A comparison of the Lysholm scores for each group was also performed. RESULTS: There were 24 (9.2%) patients who had clinical failure at a mean follow-up of 7.5 ± 4.3 years. The overall survival rate at 5 years was 92.8% (95% CI, 91.1%-94.5%). A graft tear was noted in 80 patients: 23 patients in the ET group and 57 patients in the LT group. The most common tear pattern was a meniscocapsular tear in the ET group and a complex tear in the LT group. The hazard ratios for clinical failure in the ET and LT groups were 30.7 (95% CI, 9.4-76.4; P < .001) and 4.0 (95% CI, 1.3-12.9; P = .013), respectively. The Lysholm score of the ET group (82.7 ± 14.8) was significantly lower than that of the other 2 groups (NT: 87.6 ± 11.7; LT: 90.7 ± 9.0; P = .024). CONCLUSION: An ET was a major risk factor for the clinical failure of lateral MAT. An LT was associated with a lower survival rate. An ET was also associated with worse clinical outcomes.

Postoperative change in the joint-line convergence angle is associated with inaccurate correction in open-wedge high tibial osteotomy.

OBJECTIVE: Accurate correction is a prerequisite for the favorable outcomes of open-wedge high tibial osteotomy (OWHTO). However, previous studies have reported disappointing results regarding correction accuracy despite the use of intra-operative navigation, which implies that a certain factor other than bony components is involved in the inaccurate correction (mainly overcorrection). The joint-line convergence angle (JLCA) can represent soft tissue effects in OWHTO. This study tried to determine whether the postoperative change in the JLCA (∆JLCA) led to inaccurate correction. METHODS: Medical records of 78 OWHTO patients from 2005 to 2021 were retrospectively reviewed. The hip-knee-ankle angle (HKA) was measured with a positive value indicating varus alignment. Inaccurate correction was defined as postoperative HKA < - 3°. The JLCA was measured before and 6 months after surgery on long-standing hip-to-ankle radiographs, and ∆JLCA was defined as the difference between the preoperative and 6-month postoperative JLCAs. ∆JLCA was compared between the accurate correction group and the inaccurate correction group, and a receiver operating characteristic (ROC) curve was used to obtain the cutoff ∆JLCA at which the sensitivity and the specificity for inaccurate correction were maximized. Clinical outcomes were also compared between the groups using the knee injury and osteoarthritis outcome score (KOOS) at final follow-up (60.9 ± 53.3 months postoperatively). RESULTS: Of the 78 patients, inaccurate correction was noted in 10 patients. The overall preoperative and postoperative HKAs were 7.0 ± 3.1° and - 0.4 ± 1.5°, respectively. The accurate correction group and the inaccurate correction group had a difference in ∆JLCA (p = 0.010). However, no significant difference was found in the preoperative HKA (p = 0.529). An ROC curve showed that the cutoff ∆JLCA was 1.9°. In the patients having ∆JLCA ≥ 1.9°, the mean JLCA was 4.9 ± 1.6° preoperatively and 1.7 ± 1.2° postoperatively. In the other patients having ∆JLCA < 1.9°, the mean preoperative and postoperative JLCA were 2.5 ± 1.8° and 2.3 ± 1.8°, respectively. The difference in the preoperative JLCA was significant (p < 0.001). The postoperative KOOS subscales did not differ according to correction accuracy. CONCLUSION: Inaccurate correction in OWHTO, specifically valgus overcorrection, is associated with large ∆JLCA which represents the postoperative change of soft tissue effects. Overcorrection should be checked in cases of large preoperative JLCAs.

Novel Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus in Wild Birds, South Korea.

We isolated 5 highly pathogenic avian influenza A(H5N1) clade 2.3.4.4.b viruses from wild waterfowl feces in South Korea during November 2022. Whole-genome sequencing and phylogenetic analysis revealed novel genotypes produced by reassortment with Eurasian low pathogenicity avian influenza viruses. Enhanced surveillance will be required to improve prevention and control strategies.

Association of Medial Meniscal Volume With Decreased Joint Space Width After Medial Opening-Wedge High Tibial Osteotomy.

Background: Medial opening-wedge high tibial osteotomy (MOWHTO) reduces contact stress by altering the weightbearing axis from the medial to the lateral compartment, relieves knee pain, and slows the progression of osteoarthritis. Purpose/Hypothesis: To evaluate whether the volume of the medial meniscus affects outcomes after MOWHTO. It was hypothesized that reduced medial meniscal volume would be associated with worse midterm clinical and radiographic outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Included were 59 patients who underwent MOWHTO and had ≥4 years of follow-up data. The mean follow-up period was 66.5 ± 15.1 months (range, 48-110 months). The cohort was classified into 3 groups according to the status of the medial meniscus on arthroscopic examination before osteotomy: no meniscal tear, degenerative tear leading to partial meniscectomy, and degenerative tear leading to subtotal meniscectomy. The Hospital for Special Surgery score and Knee Society objective and functional scores were compared among the groups at 2 time points (preoperative and latest follow-up), and the medial joint space width (JSW) was compared among the groups at 3 time points (preoperative, 1 year postoperative, and latest follow-up). Results: Overall, 9 patients had no meniscal tear, 20 patients underwent partial meniscectomy, and 30 patients underwent subtotal meniscectomy. The clinical scores improved significantly from preoperatively to the latest follow-up (P ≤ .001 for all), with no significant difference among the groups. Post hoc analysis indicated that at the latest follow-up, JSW was significantly lower in the subtotal meniscectomy group compared with the no-tear group on both 45° of flexion posterior-anterior (2.5 ± 1.3 vs 3.9 ± 1.8 mm; P = .004) and anterior-posterior (3.4 ± 1.1 vs 4.5 ± 0.9 mm; P = .011) radiographs. Conclusion: Subtotal meniscectomy of the medial meniscus performed during arthroscopic examination with MOWHTO was associated with decreased JSW at midterm follow-up. Efforts should be made to preserve the medial meniscus as much as possible during MOWHTO.

Difference in Joint Stability Between Small Posterior Malleolar Fragments With Fixation and Those Without Fixation: A Biomechanical Cadaver Study.

The indication for the surgical treatment of ankle fractures that involve a posterior malleolar fragment remains controversial. This cadaver study assessed the biomechanical results of rotation stiffness of Haraguchi type 1 posterior malleolar fragments with or without cannulated screw fixation. Twelve anatomic lower-extremity specimens from 6 cadavers were tested. Six right legs were subjected to posterior malleolus osteotomy (Haraguchi type I) followed with (group A; n = 3) or without (group B; n = 3) fixation using a cannulated screw. Ankle joint stability was measured under both external rotation force and axial loading, and the passive resistive torque was measured in both groups. The mean torque value in group A was 0.1093 Nm/º, while that in group B was 0.0537 Nm/º. There was a significant intergroup difference (p = .004). In group B, the torque value was further increased in the latter rotation period (about 40-60 degrees). Group A proved more stable under experimental conditions than group B. Fixation in type I posterior malleolar fragments produced improved stability in ankle rotation, even for posterior malleolar fragments involving <25% of the articular surface, and has been considered an effective aid in treatment.

Preoperative intra-articular steroid injections within 3 months increase the risk of periprosthetic joint infection in total knee arthroplasty: a systematic review and meta-analysis.

OBJECTIVE: Albeit with no disease-modifying effects, intra-articular steroid injections (IASIs) are still widely used to relieve symptoms of knee osteoarthritis. Previous literature has reported conflicting results regarding the safety of IASI in terms of periprosthetic joint infection (PJI) in total knee arthroplasty (TKA). This study tried to determine whether preoperative IASIs increased the risk of PJI, with different time intervals between the injections and surgery. METHODS: A computerized search of MEDLINE, EMBASE, and Cochrane Library was conducted for studies published before October 2022, which investigated the PJI rates of patients who received IASIs before TKA and patients who did not. The primary outcome was the association between preoperative IASI and PJI in TKA. The time point from which IASIs could be applied without risking PJI was also assessed. RESULTS: Fourteen studies, with 113,032 patients in the IASI group and 256,987 patients in the control group, were included. The pooled odds ratio of PJI was 1.13 (95% confidence interval [CI] 1.00-1.27, p = 0.05), indicating no increased risk of PJI. With the time interval < 6 months, the pooled odds ratio was 1.19 (95% CI 0.99-1.43, p = 0.06). However, with the time interval < 3 months, the pooled odds ratio was 1.26 (95% CI 1.06-1.50, p < 0.01). CONCLUSION: IASI is not a safe procedure for patients who are expected to undergo TKA. The time interval between the injections and surgery was an important factor in assessing the safety of IASI. Preoperative injections that were applied within 3 months increased the risk of PJI in TKA.

Graft Extrusion of 3 Millimeters Is Acceptable at a Minimum of 5-Year Outcomes for Lateral Meniscal Allograft Transplantation.

PURPOSE: To determine the acceptable amount of graft extrusion based on long-term radiographic outcomes in lateral meniscal allograft transplantation (MAT). METHODS: 94 lateral MAT patients with a minimum 5-year follow-up period were reviewed. Graft extrusion was measured on MRI scans taken 1 year after surgery, and the study population was divided according to the amount of extrusion: group A, extrusion <3 mm; group B, 3 mm ≤ extrusion <5 mm; and group C, extrusion ≥5 mm. For radiographic evaluation, the bilateral lateral joint space widths (JSWs) were measured on a standing 45° flexion posteroanterior radiograph. To standardize the measurements, the affected JSW was divided by the contralateral JSW. The change in the standardized JSW (ΔJSWstd) between the preoperative and latest follow-up assessments was analyzed according to the three groups. Multiple regression analysis was performed to control other related factors, such as lower limb alignment and cartilage status at the time of MAT. The acceptable amount of graft extrusion was calculated using a receiver operating characteristic (ROC) curve for the third quartile of ΔJSWstd. Clinical outcomes were evaluated using the Lysholm score and were compared among the groups. RESULTS: The mean follow-up duration was 8.3 ± 3.1 years. There were 54, 25, and 15 patients in group A, group B, and group C, respectively. In multiple regression analysis, both group B and group C had significant associations with ΔJSWstd and their beta coefficients were comparable (group B, P < .001, ß = .642; group C, P < .001, ß = 0.613). No significant difference in ΔJSWstd was found between group B and group C (P = .494). On the basis of the ROC curve, the acceptable amount of graft extrusion was 3.74 mm (sensitivity, 81.8%; specificity, 77.8%). There were no differences in the Lysholm scores among the three groups (P = .329). CONCLUSIONS: ΔJSWstd differed between graft extrusion <3 mm (group A) and graft extrusion ≥3 mm (group B and group C). However, there was no significant difference in ΔJSWstd between group B and group C. No significant difference in clinical outcomes was found according to graft extrusion. This study gave supporting evidence for the currently recognized acceptable amount of graft extrusion (3 mm). LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Age alone does not affect the joint survivorship after arthroscopic partial meniscectomy for degenerative medial meniscus tears: a propensity-score matched survival analysis.

PURPOSE: To evaluate the effect of age itself on the joint survivorship after arthroscopic partial meniscectomy (APM) for degenerative medial meniscus tears (DMTs). METHODS: Patients undergoing APM for DMTs during 1999-2010 were retrospectively reviewed. The inclusion criteria were as follows: (1) DMTs identified on preoperative MRI scans, (2) no definite history of trauma, and (3) follow-up duration more than 5 years. In evaluation of the joint survivorship, the endpoint was defined as conversion to arthroplasty (or realignment osteotomy) or progression to Kellgren-Lawrence grade 4. The study population was divided into older and younger groups by a cutoff age at which the difference in the joint survival rates was maximized, using a time-dependent receiver operating characteristic (ROC) curve. The two groups were then matched based on propensity scores. The joint survival rates were compared between the groups using Kaplan-Meier analysis, before and after propensity score matching (PSM). RESULTS: A total of 633 knees were included. The cutoff age was calculated as 60 years. Before PSM, 239 knees were allocated to the older group (≥ 60 years) and 394 knees to the younger group (< 60 years). A significant difference in the joint survival rates was noted between the groups (log-rank test, p < 0.001). After PSM, 183 knees remained in each group. The difference in the survival rates was no more statistically significant (n.s.). The latest Lysholm scores of the older and the younger groups before PSM were 72.2 ± 20.8 and 79.9 ± 19.6, respectively (p < 0.001); however, the scores after PSM were 73.2 ± 20.3 and 77.4 ± 20.5, respectively (n.s.). CONCLUSIONS: Joint survivorship after APM was affected by other factors associated with the aging process, such as cartilage status and meniscal tear pattern, rather than age itself. Advanced age should not be the only reason for precluding APM in treatment of DMTs. APM is a viable option when treating DMTs in elderly patients if adopted with caution. According to this study, a surgeon should assess the age-related factors when he considers APM in elderly patients. LEVEL OF EVIDENCE: III.

Signal intensity of lateral meniscal allografts deteriorates over time: a longitudinal MRI analysis during a minimum follow-up of 8 years.

PURPOSE: To evaluate the serial change of magnetic resonance imaging (MRI) signal intensity (SI) of lateral meniscal allografts in a long-term period of > 8 years and to determine whether the SI change adversely affected clinical outcomes. METHODS: Thirty-three lateral meniscal allograft transplantation (LMAT) patients with MRI taken > 8 years after surgery were included. The allograft was assessed using MRI at five serial time points (1, 2-4, 4-6, 6-8, and > 8 years after surgery), based on the following grading system: grade 1, globular increased SI not adjacent to the articular surface; grade 2, linear SI within the meniscus; and grade 3, increased SI extended to the articular surface. MRI evaluation was performed for three locations of the allograft (anterior horn, mid-body, and posterior horn), and the serial changes of allograft SI at each location were analyzed using the generalized estimating equation (GEE) with cumulative logit link function. The patients were classified according to SI change at each location (stationary group and deterioration group), and the two groups were compared in terms of clinical outcomes using the Lysholm score. RESULTS: The mean follow-up duration was 9.2 ± 1.2 years. During that period, SI of the allograft deteriorated over time, regardless of the location (anterior horn, p = 0.034; mid-body, p = 0.002; posterior horn, p < 0.001). The amount of SI deterioration at each location of the graft differed with a borderline significance (p = 0.050, GEE), and the proportion of grade 3 SI was higher at the posterior horn (36.4%) than at the other locations at the last follow-up (p < 0.001, chi-square test). However, no significant differences in the Lysholm scores were found between the stationary group and the deterioration group at all locations. CONCLUSION: SI of the meniscal allograft deteriorated over time at all locations during the long-term follow-up. Deterioration of the graft was more prominent at the posterior horn than at the other locations. SI deterioration did not adversely affect the clinical outcomes, which should be interpreted with caution, considering the small sample size of this study. In the prognosis of lateral MAT, SI deterioration at the posterior horn is a more determining factor than that at the other part of the allograft. Therefore, SI at the posterior horn needs to be examined with special concern. LEVEL OF EVIDENCE: III.

Age and Meniscal Extrusion Are Determining Factors of Osteoarthritis Progression after Conservative Treatments for Medial Meniscus Posterior Root Tear.

BACKGROUND: With a growing understanding of biomechanical disadvantages following medial meniscus posterior root tear (MMPRT), recent studies have focused on surgical repair of MMPRT. Because not all tears are repairable, surgical indications can be properly established when the outcomes of conservative treatments are revealed. This study tried to identify risk factors for osteoarthritis progression after conservative treatments for isolated MMPRT. MATERIALS & METHODS: Patients who had conservative treatments for isolated MMPRT during 2013-2016 were retrospectively reviewed. To evaluate osteoarthritis progression, those who were followed up for ≤3 years and those who already showed advanced osteoarthritis of Kellgren--Lawrence (K-L) grade 4 at the time of diagnosis were excluded. Because patients with varus malalignment were candidates for realignment osteotomy, conservative treatments for MMPRT were applied to patients with well-aligned knees. Osteoarthritis progression was determined based on the K-L grading system, and risk factors including age, sex, body mass index, lower limb alignment, preoperative K-L grade, meniscal extrusion, and the presence of subchondral bone marrow lesion (BML) were analyzed using logistic regression analyses. RESULTS: A total of 42 patients were followed up for 57.4 ± 26.8 months. During that period, osteoarthritis progression was noted in 17 (40.5%) patients. Based on univariate analyses for each risk factor, age, meniscal extrusion, and the presence of subchondral BML were included in the multivariate logistic regression analysis. The results showed that age (p = 0.028, odds ratio = 0.87) and meniscal extrusion (p = 0.013, odds ratio = 9.65) were significant risk factors. A receiver operating characteristic curve found that the cutoff age was 63.5 years, with the area under the curve being 0.72 (sensitivity, 68.0%; specificity, 70.6%). CONCLUSIONS: About two-fifths of patients who had conservative treatments for MMPRT underwent osteoarthritis progression in the mid to long term. Age and meniscal extrusion were determining factors of osteoarthritis progression. The risk for osteoarthritis progression was decreased when the age of patients was over 63.5 years.

Topical Tranexamic Acid Can Be Used Safely Even in High Risk Patients: Deep Vein Thrombosis Examination Using Routine Ultrasonography of 510 Patients.

Background and Objectives: Previous studies regarding tranexamic acid (TXA) in total knee arthroplasty (TKA) investigated only symptomatic deep vein thrombosis (DVT), or did not include high risk patients. The incidence of DVT including both symptomatic and asymptomatic complications after applying topical TXA has not been evaluated using ultrasonography. Materials and Methods: The medical records of 510 patients who underwent primary unilateral TKA between July 2014 and December 2017 were retrospectively reviewed. Because TXA was routinely applied through the topical route, those who had a history of venous thromboembolism, myocardial infarction, or cerebral vascular occlusive disease, were not excluded. Regardless of symptom manifestation, DVT was examined at 1 week postoperatively for all patients using ultrasonography, and the postoperative transfusion rate was investigated. The study population was divided according to the use of topical TXA. After the two groups were matched based on the propensity scores, the incidence of DVT and the transfusion rate were compared between the groups. Results: Of the 510 patients, comprising 298 patients in the TXA group and 212 patients in the control group, DVT was noted in 22 (4.3%) patients. Two patients had DVT proximal to the popliteal vein. After propensity score matching (PSM), 168 patients were allocated to each group. In all, 11 patients in the TXA group and seven patients in the control group were diagnosed with DVT, which did not show a significant difference (p = 0.721). However, the two groups differ significantly in the transfusion rate (p < 0.001, 50.0% in the TXA group, 91.7% in the control group). Conclusions: The incidence of DVT, whether symptomatic or asymptomatic, was not affected by the use of topical TXA. The postoperative transfusion rate was reduced in the TXA group. Topical TXA could be applied safely even in patients who had been known to be at high risk.

The incidence of deep vein thrombosis after anterior cruciate ligament reconstruction: An analysis using routine ultrasonography of 260 patients.

BACKGROUND: Recent studies regarding deep vein thrombosis (DVT) after anterior cruciate ligament (ACL) reconstruction investigated only symptomatic complications. The purpose of this study was to assess the true incidence of DVT after ACL reconstruction, regardless of symptom manifestation. MATERIALS AND METHODS: Medical records of 260 patients who underwent isolated ACL reconstruction between January 2014 and December 2019 were retrospectively reviewed. Regardless of symptom manifestation, DVT was examined for all patients at 1 week postoperatively using ultrasonography. Demographics, injury mechanism (high energy direct injury and low energy indirect injury), soft tissue injury, preoperative anterior laxity, tourniquet time, and surgical technique (transtibial, anteromedial portal, and outside-in techniques) were investigated. Soft tissue injury was evaluated on magnetic resonance imaging (MRI) scans, based on the Tscherne classification. Risk factors for proximal DVT were identified using logistic regression analyses. RESULTS: A total of 21 (8.1%) patients showed DVT. 5 (1.9%) patients had thrombosis at the popliteal vein; however, none of them exhibited symptoms. The other 16 patients had thrombosis at the distal veins: 1 patient at the anterior tibial vein, 5 patients at the posterior tibial vein, 3 patients at the peroneal vein, 6 patients at the soleal vein, and 1 patient at the muscular branch vein. The risk factors for proximal DVT included high energy direct injury (p = 0.013, odds ratio = 10.62) and grade 2 soft tissue injury (p = 0.039, odds ratio = 6.78). CONCLUSIONS: The true incidence of DVT, including symptomatic and asymptomatic complications, were 8.1% after ACL reconstruction. This rate is higher than the previously known incidence which has been investigated only for symptomatic patients. Injury mechanism and soft tissue injury should be assessed when considering thromboprophylaxis.

Risk Factors for Increase in Posterior Slope After Medial Open-Wedge High Tibial Osteotomy.

Background: Whether lateral hinge fracture (LHF) after open-wedge high tibial osteotomy (OWHTO) is associated with the change in tibial posterior slope (PS) has not been determined. Risk factors for PS increase are still unknown. Hypothesis: There will be no difference in patient characteristics and radiographic factors when stratified by change in tibial PS (ΔPS). Study Design: Cohort study; Level of evidence, 3. Methods: We reviewed the records of 148 patients who underwent OWHTO with locking-plate fixation from 2010 to 2016. Included were those with a minimum 2-year follow-up and true lateral radiographs before and at 1 year after surgery. ΔPS was defined as a difference between preoperative and 1-year postoperative PS, with positive values indicating PS increase. ΔPS was classified into <3°, 3° to <6°, and ≥6°. Any LHFs were grouped by Takeuchi classification as stable (type 1) or unstable (types 2 and 3). Risk factors for PS increase were evaluated using ordinal logistic regression analyses. Clinical outcomes according to ΔPS were evaluated using the Hospital for Special Surgery score. Results: There were 79 (53.4%) patients with ΔPS <3°, 44 (29.7%) with 3° ≤ ΔPS < 6°, and 25 (16.9%) with ΔPS ≥6°. LHFs were observed in 41 (27.7%) patients: 32 with type 1 and 7 and 2 with types 2 and 3, respectively. Results of the multivariate ordinal logistic regression analysis indicated that ΔPS was associated with unstable LHF (P = .005, exp[ß] = 6.34), preoperative PS (P = .028, exp[ß] = 0.90), and correction angle (P = .037, exp[ß] = 1.09). ΔPS ≥6° was seen in 4 of 9 (44.4%) patients with unstable LHF, 9 of 32 (28.1%) with stable LHF, and 12 of 107 (11.2%) with no LHF (P = .017). The mean correction angle was 11.3° ± 3.6° in patients with ΔPS ≥6°, 9.4° ± 4.6° in cases of 3° ≤ ΔPS < 6°, and 8.8° ± 3.6° in cases of ΔPS <3° (P = .019). Hospital for Special Surgery scores did not differ according to ΔPS. Conclusion: LHF type and correction angle were associated with ΔPS after OWHTO, and unstable LHF and large correction angle were risk factors for PS increase. There was no significant difference in clinical outcomes according to ΔPS.

Hidden Unstable Flap Should Be Suspected in Treating Intractable Pain from Medial Meniscus Horizontal Tear.

(1) Background: The medial meniscus horizontal tear (MMHT) is known as a lesion that can be treated nonoperatively. However, some patients show persistent pain despite conservative treatments. In arthroscopic surgery for MMHT, surgeons often encounter unexpected unstable flaps, which can explain the intractable pain. This study aimed to determine whether preoperative factors could predict the hidden unstable flaps in MMHT. (2) Materials and Methods: Medical records of 65 patients who underwent arthroscopic partial meniscectomy (APM) for isolated MMHT during 2016-2020 were retrospectively reviewed. APM was indicated when there was no severe chondral degeneration and intractable localized knee pain in the medial compartment did not resolve despite conservative treatments. Unstable flap was confirmed based on arthroscopic images and operation notes. Each of the following preoperative factors were investigated using logistic regression analyses to determine whether they can predict an unstable flap: age, sex, body mass index, lower limb alignment, trauma history, mechanical symptoms, symptom duration, visual analogue scale (VAS), Lysholm score, cartilage wear of the medial compartment, and subchondral bone marrow lesion (BML). (3) Results: Hidden unstable flaps were noted in 45 (69.2%) patients. Based on univariate analyses for each preoperative factor, age, symptom duration, cartilage wear (of the femoral condyle and the tibial plateau), and subchondral BML were included in the multivariate logistic regression analysis. The results showed that symptom duration (p = 0.026, odds ratio = 0.99) and high-grade cartilage wear of the medial femoral condyle (p = 0.017, odds ratio = 0.06) were negatively associated with unstable flaps. A receiver operating characteristic curve was used to calculate the symptom duration at which the prediction of unstable flaps was maximized, and the cutoff point was 14.0 months. (4) Conclusions: More than two thirds of patients suffering intractable pain from MMHT had hidden unstable flaps. However, APM should not be considered when the symptom duration is more than 14 months or high-grade cartilage wear of the medial femoral condyle is noted.

Insufficient Correction and Preoperative Medial Tightness Increases the Risk of Varus Recurrence in Open-Wedge High Tibial Osteotomy.

PURPOSE: To assess serial changes of limb alignment after open wedge high tibial osteotomy (HTO) using the weightbearing line (WBL) ratio in the midterm, with a focus on varus recurrence. METHODS: Patients undergoing open wedge HTO from January 2010 to December 2016 were retrospectively reviewed. Those without serial postoperative weightbearing long-leg alignment films, those who showed remained varus alignment after osteotomy, and those who had <2 years of follow-up were excluded. In terms of immediate postoperative limb alignment (≤3 months) measured using WBL ratio, cases were categorized into 4 groups: <50%, undercorrection; 50% to 57%, insufficient correction; 57% to 67%, planned correction; and >67%, overcorrection. To determine risk factors for varus recurrence (WBL ratio <50%), immediate postoperative WBL ratio category and preoperative valgus and varus stress angles (which represent medial and lateral tightness of the joint, respectively) were investigated using logistic regression analysis, taking other related factors into account. Clinical outcomes according to varus recurrence were measured using Hospital for Special Surgery (HSS) scores. RESULTS: A total of 148 cases were included. Varus recurrence was noted in 40 cases (27.0%), with a mean follow-up of 49.7 ± 21.8 months (range 24 to 102 months). The incidence of varus recurrence was different according to WBL ratio category: 10/10 (100.0%) in undercorrection; 16/33 (48.5%) in insufficient correction; 13/58 (22.4%) in planned correction; and 1/47 (2.1%) in overcorrection. Based on logistic regression analysis, insufficient correction and preoperative valgus stress angle were found to be significant risk factors (P = .038, and .008, respectively). With valgus stress angle <2°, 7 of 10 insufficient correction cases showed varus recurrence (P = .005). However, HSS scores did not differ according to varus recurrence (P = .363). CONCLUSION: Insufficient correction and preoperative medial tightness increased the risk of varus recurrence. Especially in cases where preoperative valgus stress angle was <2°, insufficient correction was strongly associated with varus recurrence. However, no significant differences in clinical outcomes were observed according to varus recurrence in the midterm. LEVEL OF EVIDENCE: III, retrospective cohort study.

Meniscal allograft transplantation shows a mismatch between anatomic and clinical failures.

PURPOSE: Clinical results of meniscal allograft transplantation (MAT) are not always consistent with graft status. This study aimed to investigate (1) the degree and pattern of mismatch between anatomic and clinical failures in MAT and (2) preoperative factors associated with the mismatch. METHODS: Two hundred and ninety-eight consecutive patients who underwent primary medial or lateral MAT during 2004-2015 were reviewed. Anatomic failure was defined as an allograft showing meniscal tear involving > 50% of the graft or unstable peripheral rim. Clinical failure included poor Lysholm score of < 65 and any requirement for re-operations such as arthroplasty, realignment osteotomy, revision MAT, and meniscectomy (more than 50% of the graft or to the zone of meniscocapsular junction). Failure cases were categorised according to the type of failure as follows: (1) type 1, anatomic failure followed by clinical failure; (2) type 2, anatomic failure did not lead to clinical failure; and (3) type 3, clinical failure without anatomic failure. Preoperative factors including age, sex, body mass index, MAT compartment, time from previous meniscectomy, alignment, cartilage status, and accompanying procedures were analysed according to the failure type. RESULTS: Forty (13.4%) patients showed anatomical or clinical failure during the median (25th-75th percentile) follow-up duration of 47 (30-72) months (range 24-178 months). Eleven (3.7%) patients showed both anatomical and clinical failure (type 1 failure). Seventeen (5.7%) patients showed anatomic failure that did not lead to clinical failure (type 2 failure). Twelve (4.0%) patients failed clinically without meniscal tear (> 50% of graft) or unstable peripheral rim (type 3 failure). Comparative analyses among failure types found a significant difference in MAT compartment (p = 0.01). In particular, the incidence of type 3 failure was higher in medial than in lateral MAT (p = 0.003). CONCLUSION: A notable number of failure cases of MAT showed a mismatch between anatomic and clinical failures. Even with anatomic failure, MAT did not always lead to poor clinical scores or re-operations, whereas MAT could have poor results without substantial allograft problems. Therefore, both anatomic and clinical aspects should be considered when evaluating MAT. In particular, type 3 failure occurred more frequently in medial than in lateral MAT. LEVEL OF EVIDENCE: III.

Increased MRI Signal Intensity of Allografts in the Midterm Period After Meniscal Allograft Transplant: An Evaluation of Clinical Significance According to Location and Morphology.

BACKGROUND: Magnetic resonance imaging (MRI) is an effective tool for objective evaluation after meniscal allograft transplant (MAT). Little is known about the association between MRI features of allograft and clinical outcomes. PURPOSE/HYPOTHESIS: To assess the degree and location of signal intensity (SI) as well as the morphology of allografts on MRI after MAT and evaluate the association between clinical outcomes and MRI features in the midterm period. It was hypothesized that a high SI accompanied by a deformed allograft in specific locations on MRI would be associated with inferior clinical outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Included were patients who underwent MAT with fresh-frozen allografts and had >3 years of follow-up with 3.0-T MRI scans. Allograft status was assessed by SI on MRI as grade 0 (normal), grade 1 (globular increased SI not adjacent to the articular surface), grade 2 (linear SI within the meniscus), or grade 3 (increased SI extended to the articular surface). Allograft morphology was assessed by the presence of distorted contours. Clinical outcomes were evaluated using the Lysholm score. The association between clinical outcomes and MRI findings was assessed by multiple linear regression analysis. RESULTS: A total of 138 patients (156 MAT procedures: 132 lateral, 24 medial) with a mean follow-up period of 55.4 ± 19.9 months (range, 36-110 months) were enrolled in this study. Grade 3 SI was observed in the posterior meniscus root and posterior third of the allograft in 39 (25%) and 62 (39.7%) MATs, respectively. Among the 62 MATs with grade 3 SI in the posterior third of the allograft, 34 (54.8%) were accompanied by distorted allograft contour. The presence of grade 3 SI with distorted contour in the posterior third of the allograft was significantly associated with inferior outcomes (ß = -6.5 [95% CI, -12.5 to -0.5]; P < .035), as was the presence of grade 3 SI in the posterior meniscus root (ß = -5.5 [95% CI, -10.5 to -0.4]; P < .034). CONCLUSION: On MRI evaluation in the midterm period after MAT, grade 3 SIs of the meniscal allograft were observed in about a third of the cases, and the association with clinical outcomes was dependent on the specific location and morphology of the allograft on MRI.