Clinical impact of ampulla of Vater cancer subtype classification based on immunohistochemical staining.

BACKGROUND: The histological subtype is an important prognostic factor for ampulla of Vater (AoV) cancer. This study proposes a classification system for the histological subtyping of AoV cancer based on immunohistochemical (IHC) staining and its prognostic significance. METHODS: Seventy-five AoV cancers were analyzed for cytokeratin 7 (CK7), CK20, and causal-type homeobox transcription factor 2 (CDX2) expression by IHC staining. We differentiated the subtypes (INT, intestinal; PB, pancreatobiliary; MIX, mixed; NOS, not otherwise specified) into classification I: CK7/CK20, classification II: CK7/CK20 or CDX2, classification III: CK7/CDX2 and examined their associations with clinicopathological factors. RESULTS: Classifications I, II, and III subtypes were INT (7, 10, and 10 cases), PB (43, 37, and 38 cases), MIX (13, 19, and 18 cases), and NOS (12, 9, and 9 cases). Significant differences in disease-free survival among the subtypes were observed in classifications II and III using CDX2; the PB and NOS subtype exhibited shorter survival time compared with INT subtype. In classification III, an association was revealed between advanced T/N stage, poor differentiation, lymphovascular invasion (LVI), the PB and NOS subtypes, and recurrence risk. In classification III, the subtypes differed significantly in T/N stage and LVI. Patients with the PB subtype had advanced T and N stages and a higher incidence of LVI. CONCLUSIONS: Classification using CDX2 revealed subtypes with distinct prognostic significance. Combining CK7 and CDX2 or adding CDX2 to CK7/CK20 is useful for distinguishing subtypes, predicting disease outcomes, and impacting the clinical management of patients with AoV cancer.

The Impact of Patellar Position on Mediolateral Joint Gap in Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty: A Prospective Study.

BACKGROUND: This prospective study aimed to investigate the influence of patellar position (ie, eversion, lateralization, and reduction) on medial and lateral gap measurements during total knee arthroplasty (TKA) in both cruciate-retaining (CR) and posterior-stabilized (PS) TKA designs. METHODS: The present work analyzed 50 knees with primary osteoarthritis that underwent TKA between July and November 2019. Medial and lateral gaps were measured at different knee flexion angles (0°, 45°, 90°, and 120°) in 3 patellar positions after sequentially inserting CR type and PS type trial component in the same knee. RESULTS: In CR TKA, medial gaps in patellar reduction showed significantly smaller gaps at 90° and 120° of knee flexion compared to those in eversion and lateralization (P < .001). Lateral gaps in patellar reduction were also significantly larger than those in eversion and lateralization (P < .001). The mediolateral gap difference in patellar reduction was significantly greater at all flexion angles compared to those in eversion and lateralization (P < .001). In PS TKA, similar patterns were observed for medial gaps, lateral gaps, and mediolateral gap differences (P < .001). CONCLUSIONS: The ligament balancing with the patella everted or subluxed may lead to an overly tight medial gap and/or loose lateral gap in the knee with a closed arthrotomy, which has potential consequences for knee function in both CR and PS TKA designs. The results of this study highlight the importance of considering patellar position to ensure optimal soft-tissue balance and joint stability in TKA.

Preoperative radiographic parameters in the case of using a narrow-version femoral implant in total knee arthroplasty.

BACKGROUND: Recently, total knee arthroplasty (TKA) designs that allow the use of narrow-version femoral implants have been introduced to avoid femoral overhang. The purpose of this study was to investigate the frequency of the use of narrow-version femoral implants and identify the difference in radiographic parameters between using a narrow-version femoral implant and a standard-version femoral implant in TKA. METHODS: A retrospective study was conducted on 504 primary TKAs using a TKA system (Anthem or Persona) that allowed narrow-version femoral implants. Anteroposterior (AP) dimension, mediolateral (ML) dimension, and modified aspect percentage ratio (ML/AP dimension) of the distal femur in preoperative radiographs were compared between a standard-version group (n = 275) and a narrow-version group (n = 229). A cut-off value of a modified aspect percentage ratio indicating the need for a narrow-version femoral implant was determined using the receiver operating characteristic (ROC) curve. RESULTS: Mean ML dimension was 80.9 ± 6.1 mm in the standard-version group and 77.3 ± 4.4 mm in the narrow-version group (p < 0.001). Mean modified aspect percentage ratio was 138.8 ± 8.1% in the standard-version group and 131.7 ± 6.3% in the narrow-version group (p < 0.001). The optimum cut-off point of the modified aspect percentage ratio for narrow-version femoral implants was 135.4% (sensitivity: 72.0%; specificity: 66.7%) for Anthem and 133.3% (sensitivity: 75.9%, specificity: 76.4%) for Persona. CONCLUSION: In the narrow-version femoral implant group, the ML dimension and the mean modified aspect percentage ratio were smaller than in the standard-version femoral implant group. A smaller modified aspect percentage ratio of the distal femur in preoperative radiographs could predict the need for narrow-version femoral implants in TKA. It was suggested that the cut-off point could be suggested as 135.4% for Anthem TKA design and 133.3% for Persona TKA design. These radiographic parameters are cost-effective and easily applicable for planning a TKA.A smaller modified aspect percentage ratio of the distal femur in preoperative radiographs could predict the need for narrow-version femoral implants in TKA. The cut-off point was 135.4% for Anthem TKA design and 133.3% for Persona TKA design.

A Retrospective Comparison of Single-Bundle Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Tenodesis With Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To compare postoperative objective knee stability and clinical outcomes between double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and single-bundle (SB) ACLR combined with lateral extra-articular tenodesis (LET). METHODS: ACL-injured patients with grade 3 pivot-shift who underwent either DB ACLR (DB ACLR group) or SB ACLR with LET (SB ACLR+LET group) were enrolled. All patients who met inclusion and exclusion criteria were retrospectively evaluated for knee laxity (the anterior translation and pivot-shift grade), clinical outcomes using the International Knee Documentation Committee (IKDC) examination form, Kellgren-Lawrence grade, graft maturation score on second-look arthroscopy, and revision rates at the last follow-up. RESULTS: From an initial cohort of 171 consecutive patients over a 3-year period, 95 (56%) met inclusion and exclusion criteria. The SB ACLR+LET group (n = 47) showed significantly better results in pivot-shift grade at the last follow-up as compared with the DB ACLR group (n = 48) (P = .021). In the SB ACLR+LET group, 93.6% (44/47) were grade 0, whereas 72.9% (35/48) in the DB ACLR group were grade 0. The SB ACLR+LET group (grade A: 42, grade B: 4 and grade C: 1) showed significantly superior results in IKDC objective grade compared with the DB ACLR group (grade A: 32; grade B: 8; and grade C: 8) (P = .017). However, no statistically significant difference could be shown in anterior translation, subjective functional IKDC score, or revision rate between the 2 groups. The mean follow-up duration was 49.7 ± 5.7 months. CONCLUSIONS: SB ACLR + LET demonstrated fewer pivot-shifts (P = .021) and superior IKDC objective grades (P = .017) than a DB ACLR at a mean follow-up of almost 50 months. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Degree of Anterolateral Ligament Injury Impacts Outcomes After Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To evaluate the effect of anterolateral ligament (ALL) injury identified on preoperative magnetic resonance imaging (MRI) on postoperative outcomes after double-bundle (DB) anterior cruciate ligament reconstruction (ACLR). METHODS: For this retrospective study, the inclusion criteria were patients who were at least 3 years out of DB ACLR. Exclusion criteria included a delay in MRI over 4 weeks, delay in surgery over 6 months, single-bundle ACLR, and revision surgery. Enrolled patients were divided into 2 groups according to the ALL injury grade in preoperative MRI by a musculoskeletal radiologist who was blinded to the perioperative findings (the high-grade group with complete or nearly complete tear: n = 53 and the low-grade group with intact ALL or partial tear: n = 33). Knee laxity, clinical outcomes using the International Knee Documentation Committee (IKDC) examination form, and revision rates were compared at the last follow-up (8.1 ± 2.2 years). An independent t test was applied to compare continuous variables, and χ2 or Fisher exact test was used to compare the nominal variables. RESULTS: The anterior translation was 3.2 ± 1.9 mm in the high-grade group and 1.6 ± 1.0 mm in the low-grade group (P < .001). The high-grade group showed 18 cases with a pivot-shift grade of 2 or 3 (40.0%); however, the low-grade group showed only 1 case with a pivot-shift grade 2 or 3 (3.0%) (P = .002). The high-grade group also showed inferior outcomes in the IKDC objective grade (grade A: 49.0%; grade B: 17.0%; grade C: 30.2%; grade D: 3.8% vs grade A: 90.9%; grade B: 6.1%; grade C: 3.0%; grade D: 0%, P = .001) and IKDC subjective score (87.5 ± 9.9 vs 93.9 ± 5.3, P < .001). In addition, the high-grade group showed a greater revision rate (11.3% vs 0%, P = .045). CONCLUSIONS: DB ACLR for patients with high-grade ALL injury resulted in increased knee laxity, worse clinical outcomes, and higher revision rate compared to patients with low-grade ALL injury. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Double-Bundle Anterior Cruciate Ligament Reconstruction With Lateral Extra-Articular Tenodesis Is Effective in Restoring Knee Stability in a Chronic, Complex Anterior Cruciate Ligament-Injured Knee Model: A Cadaveric Biomechanical Study.

PURPOSE: To compare knee stability after intra-articular isolated double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) and single-bundle (SB) and DB ACLR combined with lateral extra-articular tenodesis (LET) in a chronic, complex anterior cruciate ligament (ACL)-injured knee model. METHODS: In 10 fresh-frozen cadaveric knees, we measured knee laxity in the following order: (1) intact knee; (2) ACL-sectioned knee; (3) complex ACL-injured knee model with additional sectioning of the anterolateral complex and the posterior horns of the medial and lateral menisci; (4) SB ACLR plus LET; (5) DB ACLR; and (6) DB ACLR plus LET. RESULTS: In comparison with the intact knee, significantly increased internal rotation (IR) laxity persisted at 60° and 90° after DB ACLR (P = .002 and P = .003, respectively). SB ACLR plus LET and DB ACLR plus LET resulted in significant reductions in IR laxity at 90° (P = .003 and P = .037, respectively), representing overconstraint in IR. SB ACLR plus LET resulted in persistently increased external rotation (ER) laxity at 30°, 60°, and 90° (P = .001, P < .001, and P < .001, respectively). The DB ACLR condition persistently showed significant increases in anterior tibial translation laxity at 60° and 90° (P = .037 and P = .024, respectively). A greater increase in ER laxity was seen after SB ACLR plus LET versus DB ACLR plus LET at 30°, 60°, and 90° (P < .001, P < .001, and P < .001, respectively). CONCLUSIONS: DB ACLR plus LET restored intact knee stability in IR, ER, and anterior tibial translation laxity at 0°, 30°, 60°, and 90° of knee flexion except for overconstraint in IR at 90° in a chronic, complex ACL-injured knee model. CLINICAL RELEVANCE: This cadaveric study provides some biomechanical evidence to support performing DB ACLR combined with LET to restore knee stability after a complex, chronic knee injury involving an ACL tear combined with anterolateral complex injury and irreparable tears of the posterior horns of the medial and lateral menisci.

Elongation Patterns of the Anterior and Posterior Borders of the Anterolateral Ligament of the Knee.

PURPOSE: To compare the elongation patterns of the anterior and posterior borders of the anterolateral ligament (ALL) at varying knee flexion angles with the knee in a neutral position without any external forces and with external forces applied, including anterior-posterior translation, internal-external rotation, and varus-valgus angulation. METHODS: Eight cadaveric knees were tested in a custom knee testing system. Elongation of the anterior and posterior borders of the ALL was measured using a MicroScribe 3DLX system at knee flexion angles of 0°, 30°, 60°, and 90° and after the application of internal-external rotation, anterior-posterior translation, and varus-valgus angulation. RESULTS: The anterior border showed a slight noncontinuous increase in percentage elongation (0.8% ± 2.2%) whereas the posterior border showed a continuous decrease in percentage elongation (-12.0% ± 2.8%) as knee flexion increased (P < .001). Apart from the elongation of the posterior border at 90° of knee flexion, internal rotation, varus angulation, and anterior translation resulted in a significant increase in the percentage elongation of the anterior and posterior borders at each flexion angle compared with external rotation, valgus angulation, and posterior translation, respectively. CONCLUSIONS: The ALL shows different elongation patterns between the anterior and posterior borders, with a continuous decrease in the percentage elongation of the posterior border as knee flexion increases. CLINICAL RELEVANCE: This study presents useful evidence to resolve the uncertainty regarding the change in length of the ALL at various degrees of knee flexion. This information may be helpful for deciding the optimal knee flexion angle during ALL graft fixation. The findings from this study suggest that graft fixation during ALL reconstructions should be performed at close to full extension of the knee.

Outcomes After Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To identify the risk factors predicting unsatisfactory postoperative clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using multivariate logistic regression. METHODS: Inclusion criteria were consecutive DB ACL reconstructions from January 2006 to September 2012 with a minimum 3-year follow-up. Exclusion criteria included (1) a delay to surgery from initial injury of more than 4 years (210 weeks); (2) contralateral knee pathology; (3) the lack of postoperative 3-dimensional computed tomography; (4) single-bundle ACL reconstruction; (5) revision ACL reconstruction; (6) meniscus allograft transplantation after total or subtotal meniscectomy; (7) multiple ligament surgeries. According to the overall International Knee Documentation Committee (IKDC) rating at the last follow-up, we sorted all enrolled subjects into superior (IKDC grade A or B) and inferior outcome groups (IKDC grade C or D). Multivariate logistic regression was used to analyze risk factors, including age, gender, body mass index, time from injury to surgery, posterior tibial slope, notch width index, cartilage injury, meniscus injury, and femoral and tibial tunnel positions. RESULTS: In comparison between the superior outcome group (n = 240) and inferior outcome group (n = 50), anterior (adjusted odds ratio [OR]: 0.902, 95% confidence interval [CI]: 0.846-0.962) or distal (adjusted OR: 1.025, 95% CI: 1.006-1.060) femoral anteromedial tunnel position was a significant risk factor for the inferior outcomes. Partial meniscectomy of medial (adjusted OR: 49.002, 95% CI: 7.047-340.717) or lateral (adjusted OR: 14.974, 95% CI: 2.181-102.790) meniscus and delayed time from injury to surgery (adjusted OR: 1.062, 95% CI: 1.023-1.102) were also a significant predictor. CONCLUSION: Anterior or distal anteromedial femoral tunnel position, partial meniscectomy of medial or lateral meniscus, and prolonged surgical delay of more than 11.5 weeks from injury were significant risk factors for the inferior clinical outcomes after DB ACL reconstruction. LEVEL OF EVIDENCE: Level III, retrospective therapeutic case series.

Risk of Emergency Operations, Adverse Maternal and Neonatal Outcomes according to the Planned Gestational Age for Cesarean Delivery.

BACKGROUND: The objective of this study was to assess the risk of emergency cesarean deliveries (CDs) and adverse neonatal/maternal outcomes according to the planned gestational age at delivery (GAD) for elective CD. METHODS: The study population consisted of term singleton pregnant women who were booked for elective CD and were subsequently delivered at term by CD, after excluding cases with a trial of labor. The relationship between the planned GAD, risk of emergency CD prior to planned date, and adverse neonatal/maternal outcomes were determined. RESULTS: The frequency of emergency CD, adverse neonatal and maternal outcomes were 9.5%, 4.5%, and 5.9%, respectively. The risk of emergency CD prior to the planned delivery date increased significantly according to the planned GAD (5.8% at 37 weeks, 8.2% at 38 weeks, 13.6% at 39 weeks, and 26.7% at 40 weeks or more of planned GAD, P = 0.005). Emergency CD was associated with an increased risk of adverse maternal outcomes, whereas the risk of adverse neonatal outcomes did not differ. In the total study population including both cases with elective and emergency CD, the risk of adverse maternal outcomes did not increase according to the planned GAD, and the risk of adverse neonatal outcomes decreased significantly according to the planned GAD. CONCLUSION: The risk of emergency CD increased as the planned GAD increased, but the risk of adverse maternal outcomes did not increase and the risk of adverse neonatal outcomes decreased significantly according to the planned GAD in the total study population including elective/emergency CD.

Repair of the Posterior Third of the Meniscus During Meniscus Allograft Transplantation: Conventional Inside-Out Repair Versus FasT-Fix All-Inside Repair.

PURPOSE: To compare conventional inside-out (IO) repair and all-inside (AI) repair for the posterior third of the meniscus during meniscus allograft transplantation (MAT). METHODS: Among the 64 enrolled patients, 31 patients underwent MAT with conventional IO repair, and 33 patients underwent MAT with AI repair using the FasT-Fix instrument for the posterior third of the meniscus allograft. All of the patients were retrospectively evaluated through clinical assessment at the last follow-up (54.3 months in the IO group and 55.4 months in the AI group) and through magnetic resonance imaging assessment for meniscal extrusion at 1 year postoperatively. Thirty patients (15 in each group) were evaluated through second-look arthroscopy at 1 year postoperatively. RESULTS: There was no significant difference in the mean Lysholm score (91.3 in the IO group and 92.3 in the AI group; P = .358) or the mean Tegner activity scale (7.1 in each group; P = .885) between the 2 groups. There was no significant difference in the mean meniscal extrusion (2.6 mm in the IO group and 2.8 mm in the AI group; P = .454), relative percentage of extrusion value (25.6% in the IO group and 24.7% in the AI group; P = .721), or meniscal healing on second-look arthroscopy (P = .796) between the 2 groups. The difference in operative time between the 2 groups was found to be statistically significant (169.9 minutes in the IO group and 123.3 minutes in the AI group; P < .001). CONCLUSIONS: Our comparative study on the different techniques for posterior repair of meniscus allograft suggested that AI posterior repair using FasT-Fix could be an alternative method to conventional IO repair as it gives a similar postoperative result and requires a shorter operative time.

Risk Factors of False-Negative Magnetic Resonance Imaging Diagnosis for Meniscal Tear Associated With Anterior Cruciate Ligament Tear.

PURPOSE: To identify risk factors that predict false-negative magnetic resonance imaging (MRI) diagnosis for meniscal tear coincident with anterior cruciate ligament injury using multivariate logistic regression. METHODS: We reviewed the medical records of consecutive patients who underwent arthroscopic anterior cruciate ligament reconstruction from January 2006 through December 2014. Exclusion criteria were no meniscal tear or incomplete tear less than 10 mm in length, delay to surgery from initial injury more than 1 year, delay to surgery from preoperative MRI more than 4 weeks, revisions, fracture histories, and multiple ligament injuries. According to preoperative MRI diagnosis, the meniscal tears were sorted into true-positive MRI and false-negative MRI groups. Multivariate logistic regression was used to analyze risk factors including age, gender, body mass index, time from injury to MRI, knee instability, concomitant ligament injury, intra-articular effusion, bone contusion, cartilage injury, meniscal tear location, and meniscal tear pattern. RESULTS: Enrolled 249 meniscal tears (159 medial and 90 lateral menisci) were sorted into true-positive MRI (n = 136) and false-negative MRI (n = 113) groups. As time from injury to MRI diagnosis increased, the risk of the false-negative MRI diagnosis decreased (adjusted odds ratio [OR], 0.859; 95% confidence interval [CI], 0.802-0.921). Meniscal tear location within the posterior one-third was a significant risk factor compared with tear within the anterior one-third (adjusted OR, 11.823; 95% CI, 2.272-61.519). Peripheral longitudinal tear pattern was also a significant risk factor (adjusted OR, 3.522; 95% CI, 1.256-9.878). CONCLUSIONS: Significant risk factors for false-negative MRI included short time from injury to MRI diagnosis, meniscal tear location within the posterior one-third, and peripheral longitudinal tear pattern. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Multivariate Analysis of Risk Factors of Graft Extrusion After Lateral Meniscus Allograft Transplantation.

PURPOSE: To identify risk factors that predict major graft extrusion (>3 mm in relation to the margin of the tibial plateau) on magnetic resonance imaging (MRI) after lateral meniscus allograft transplantation (MAT) using multivariate logistic regression. METHODS: In this retrospective trial, inclusion criteria were consecutive lateral MATs from January 2004 to June 2013. Exclusion criteria were the lack of postoperative MRI, loss to follow-up for minimum 2 years, and simultaneous surgery of the articular cartilage or anterior cruciate ligament. According to the measured extent of graft extrusion in postoperative MRI, the lateral MATs were sorted into minor extrusion and major extrusion groups. Multivariate logistic regression was used to analyze risk factors including age, gender, body mass index, time from previous meniscectomy to MAT, extent of previous meniscectomy, previous anterior cruciate ligament reconstruction, knee alignment angle, Kellgren-Lawrence grade, lateral peripheral osteophyte, Outerbridge grade, posterior repair technique the position of bony bridge, and axial plane trough angle. RESULTS: Enrolled 72 lateral MATs were sorted into minor extrusion (n = 34) and major extrusion groups (n = 38). As time from previous meniscectomy to lateral MAT increased, the risk of the major graft extrusion after lateral MAT increased (adjusted odds ratio: 1.554, 95% confidence interval: 1.089 to 2.218). Increased axial plane trough angle was also a significant risk factor (adjusted odds ratio: 8.449, 95% confidence interval: 1.710 to 42.250). The other parameters were not significant risk factors. CONCLUSIONS: Most meniscal grafts after lateral MATs showed major graft extrusion. Significant risk factors for the major graft extrusion included delayed time from previous meniscectomy to MAT and increased axial plane trough angle. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Risk Factors for Radiographic Progression of Osteoarthritis After Meniscus Allograft Transplantation.

PURPOSE: To identify risk factors that predict radiographic progression of osteoarthritis after meniscus allograft transplantation (MAT) using multivariate logistic regression. METHODS: Inclusion criteria were consecutive patients who underwent medial or lateral MATs from January 2005 to September 2012 by one surgeon. Exclusion criteria were lack of postoperative magnetic resonance image, loss to follow-up for a minimum of 3 years, and simultaneous surgery on articular cartilage or the anterior cruciate ligament. According to the change of Kellgren-Lawrence (KL) grade at the mean final follow-up of 56.2 months, the enrolled MATs were sorted into the no progression of osteoarthritis (NOA) and progression of osteoarthritis (POA) groups. Multivariate logistic regression was used to analyze risk factors, including age, sex, body mass index, time from previous meniscectomy to MAT, extent of previous meniscectomy, previous anterior cruciate ligament reconstruction, knee alignment angle, KL grade, side of transplanted meniscus, Outerbridge grade, posterior repair technique, and relative percentage of extrusion. RESULTS: In comparison between the NOA (n = 38) and the POA (n = 31) groups, a significant risk factor for radiographic progression of osteoarthritis after MAT was medial MAT compared with lateral MAT. Medial MAT compared with lateral MAT was also a significant risk factor (adjusted odds ratio, 3.763; 95% confidence interval, 1.212-11.683). CONCLUSIONS: Patients need to be counseled about the increased risk of osteoarthritis progression after MAT over time, particularly for medial MAT. LEVEL OF EVIDENCE: Level III, retrospective case control study.

Risk factors for knee instability after anterior cruciate ligament reconstruction.

PURPOSE: The objective of this study was to estimate risk factors that influence postoperative instability after anterior cruciate ligament (ACL) reconstruction using multivariate logistic regression analysis. METHODS: A total of 152 consecutive patients with symptomatic ACL insufficiency underwent arthroscopic ACL reconstruction between 2005 and 2011. Loss to follow-up and previous ligament reconstruction were exclusion criteria, resulting in 131 patients remaining for this retrospective study. The median follow-up was 55 months (range 25-100 months). Patients were sorted into two groups by anterior translation on stress radiograph and pivot shift test grade and were analysed for the statistical significance of various risk factors including age at surgery, gender, body mass index, preoperative instability, time from injury to surgery, single-bundle reconstruction with preserved abundant remnant versus double-bundle reconstruction with scanty remnant, and concomitant ligament, meniscus, and articular cartilage injury with use of multivariate logistic regression analysis. RESULTS: Time from injury to surgery over 12 weeks was found to be a significant risk factor for postoperative instability [p < 0.001, adjusted odds ratio (OR) 6.22; 95 % confidence interval (CI) 2.14-18.06)]. Grade 2 injury of medial collateral ligament (MCL) was also a risk factor (p = 0.02, adjusted OR 13.60; 95 % CI 1.24-148.25). The other variables were not found to be a significant risk factor. CONCLUSIONS: Among the risk factor variables, concomitant grade 2 MCL injury and surgical delay of more than 12 weeks from injury were significant risk factors for postoperative knee instability after ACL reconstruction. The overall results suggest that surgery <12 weeks from injury and meticulous attention to concomitant MCL injury should be considered. LEVEL OF EVIDENCE: Retrospective case-control study, Level III.

Reduction Osteotomy vs Pie-Crust Technique as Possible Alternatives for Medial Release in Total Knee Arthroplasty and Compared in a Prospective Randomized Controlled Trial.

BACKGROUND: To compare the gap change between the pie-crust technique and reduction osteotomy to determine their effects on flexion and extension gaps and their success rates in achieving ligament balancing during total knee arthroplasty. METHODS: In a prospective randomized controlled trial, 106 total knee arthroplasties were allocated to each group with 53 cases. If there was a narrow medial gap with an imbalance of ≥3 mm after the initial limited medial release, either reduction osteotomy or pie-crust technique was performed. The changes of extension and flexion medial gaps along with the success rate of mediolateral balancing were compared. RESULTS: There was a significant difference in the change of medial gap in knee extension with mean changes of 3.5 ± 0.5 mm and 2.3 ± 0.8 mm in the reduction osteotomy and pie-crust groups, respectively (P < .001). For flexion gap, greater change was found in the pie-crust group compared with the reduction osteotomy group; the mean medial gap changes in knee flexion were 1.1 ± 0.5 mm and 2.3 ± 1.2 mm in the reduction osteotomy and pie-crust groups, respectively. The success rates were 90.6% and 67.9% in reduction osteotomy and pie-crust groups, respectively (P = .007). CONCLUSION: As an alternative medial release method, reduction osteotomy was more effective in extension gap balancing, and pie-crust technique was more effective in flexion gap balancing. The overall success rate of mediolateral ligament balancing was higher in the reduction osteotomy group than in the pie-crust group.

Varus-valgus stress radiograph as a predictor for extensive medial release in total knee arthroplasty.

PURPOSE: The purpose of this study was to identify the risk factors for predicting the reduction osteotomy as extensive medial release during total knee arthroplasty (TKA) using multivariate logistic regression. METHODS: A total of 404 TKAs were enrolled and sorted into two groups according to the extent of medial release and then analysed for the statistical significance of various risk factors including age, gender, body mass index (BMI), pre-operative knee mechanical axis angle (KMAA), mechanical varus stress angle (MVrSA), mechanical valgus stress angle (MVgSA), and sum of the mechanical varus and valgus stress angles (SMVVA) with use of multivariate logistic regression analysis. RESULTS: SMVVA to a more varus direction was found to be a significant risk factor for the reduction osteotomy (p < 0.0001, adjusted odds ratio (OR) = 2.705 with 95 % CI 2.126-3.443). KMAA and MVgSA to a more varus direction were also significant risk factors (p = 0.010, adjusted OR = 1.189 with 95 % CI 1.041-1.357, and p = 0.005, adjusted OR = 1.401 with 95 % CI 1.109-1.767). The other variables were not significant risk factors. CONCLUSIONS: The overall results suggest that careful attention should be given to the need for extensive medial release and failure of the conventional soft tissue release technique during TKA in patients with a greater varus angle in the pre-operative SMVVA, MVgSA, and KMAA, especially with a greater varus SMVVA, which was the strongest predictor of reduction osteotomy. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Risk factors of post-operative malalignment in fixed-bearing medial unicompartmental knee arthroplasty.

PURPOSE: The purpose of this study was to identify risk factors of post-operative malalignment in medial unicompartmental knee arthroplasty (UKA) using multivariate logistic regression. METHODS: We retrospectively enrolled 92 patients who had 127 medial UKAs. According to post-operative limb mechanical axis (hip-knee-ankle [HKA] angle), 127 enrolled knees were sorted into acceptable alignment with HKA angle within the conventional ± 3 degree range from a neutral alignment (n = 73) and outlier with HKA angle outside ± 3 degree range (n = 54) groups. Multivariate logistic regression was used to analyse risk factors including age, gender, body mass index, thickness of polyethylene tibial insert, pre-operative HKA angle, distal femoral varus angle (DFVA), femoral bowing angle (FBA), tibial bone varus angle (TBVA), mechanical distal femoral and proximal tibial angles, varus and valgus stress angles, size of femoral and tibial osteophytes, and femoral and tibial component alignment angles. RESULTS: Pre-operative DFVA, TBVA and valgus stress angle were identified as significant risk factors. As DFVA increased by one degree, malalignment was about 45 times probable (adjusted OR 44.871, 95 % CI 2.608-771.904). Shift of TBVA and valgus stress angle to a more varus direction were also significant risk factors (adjusted OR 13.001, 95 % CI 1.754-96.376 and adjusted OR 2.669, 95 % CI 1.054-6.760). CONCLUSIONS: Attention should be given to the possibility of post-operative malalignment during medial UKA in patients with a greater varus angle in pre-operative DFVA, TBVA and valgus stress angle, especially with a greater varus DFVA, which was the strongest predictor for malalignment.

Arthroscopic repair of horizontal meniscal cleavage tears with marrow-stimulating technique.

PURPOSE: The purpose of this study was to evaluate patients after arthroscopic repair of meniscal horizontal tears with a marrow-stimulating technique through clinical signs and second-look arthroscopy. METHODS: We retrospectively reviewed a consecutive series of 32 meniscal repairs with horizontal cleavage tears and evaluated them through clinical assessment and second-look arthroscopic examinations. Arthroscopic meniscal repair and a marrow-stimulating technique were performed. Functional outcomes were evaluated using the visual analog scale (VAS) pain score, Lysholm knee scoring scale, and Tegner activity scale. Assessment of meniscal healing was evaluated clinically by the presence of meniscal signs; second-look arthroscopy was performed in 11 patients. Correlation between chronicity of a meniscal lesion (time from initial symptom [TFIS]) and meniscal healing was evaluated. RESULTS: The mean follow-up period was 45.6 ± 13.9 months. Improvements in mean VAS scores from 6.7 to 1.9 (P < .001) were observed. The Lysholm score increased from 48.0 ± 14.4 to 92.0 ± 6.3 (P < .001). The Tegner activity score increased from 3.3 ± 1.1 to 6.8 ± 0.8 (P < .001). At the last follow-up, 29 of 32 patients (91%) were evaluated as healing in the clinical assessment. Of the 11 patients who underwent second-look arthroscopy, 8 (73%) showed complete healing, 2 (18%) had incomplete healing, and 1 (9%) failed to heal. Correlation between TFIS and meniscal healing was clinically significant (P = .001) but arthroscopically insignificant (P = .085) on second-look arthroscopy. CONCLUSIONS: The meniscal repair procedure for horizontal cleavage tears in the present study suggests an alternative treatment option to approach the treatment of meniscal tears extending into the avascular zone and degenerative tissue. The marrow-stimulating technique using a cannulated reamer can be considered as an alternative method for the augmentation of meniscal healing. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Anatomic Placement of the Femoral Tunnels in Double-Bundle Anterior Cruciate Ligament Reconstruction Correlates With Improved Graft Maturation and Clinical Outcomes.

PURPOSE: To compare maturation of reconstructed graft on second-look arthroscopy and clinical outcomes between 2 groups: the provisional anatomic (PA) group, with both the anteromedial (AM) and posterolateral (PL) femoral tunnels in their anatomic location, and the nonanatomic (NA) group, with either 1 of the 2 femoral tunnels beyond its anatomic location after double-bundle anterior cruciate ligament reconstruction. METHODS: We enrolled 154 patients who underwent 3-dimensional computed tomography scanning and second-look arthroscopy after double-bundle anterior cruciate ligament reconstruction. All of the patients were divided into the PA and NA groups according to the femoral tunnel position determined by the quadrant method. Graft maturation was evaluated with 3 subsections, including integrity, tension, and synovial coverage with revascularization, on second-look arthroscopy. We also compared Lachman test, pivot-shift test, KT-2000 (MEDmetric, San Diego, CA), and International Knee Documentation Committee grades at the last follow-up. RESULTS: Of the 154 patients, 88 were classified as the PA group and 66 as the NA group by the quadrant method. A difference existed between groups for the AM tunnel position but not for the PL tunnel position. The PA group showed a higher graft maturation score (P < .001 for all comparisons) and better results according to the International Knee Documentation Committee knee rating, Lachman test, pivot-shift test, and KT-2000 assessment (P < .001 for all comparisons). CONCLUSIONS: The PA group with anatomic femoral tunnel placement showed a higher graft maturation score on second-look arthroscopy, along with better clinical outcomes, than the NA group. There was a significant difference in the AM femoral tunnel position but not in the PL tunnel position between the 2 groups. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

The effect of multiple drilling on a sclerotic proximal tibia during total knee arthroplasty.

PURPOSE: To assess the depth of cement penetration and the occurrence of radiolucent line (RLL) according to drill bit diameter used in multiple drilling for the sclerotic bone of the medial proximal tibia during total knee arthroplasty (TKA). METHODS: The multiple drilling procedure was performed with 2.0 mm diameter in group 1 (n = 290) and with 4.5 mm diameter in group 2 (n = 109) to enhance the cement penetration. The postoperative RLL in the cement-bone interface and the depth of cement penetration were measured under the tibial implant at three, six, 12 and 24 months after TKA. The progression of RLL was also evaluated at the latest follow-up. RESULTS: Cumulative occurrence rates of RLLs were significantly lower in group 2 than in group 1 at 12 and 24 months postoperatively (P = 0.005 and 0.004). The depth or width was increased in nine cases only in group 1 at the latest follow up. There was no tibial implant loosening in both groups at the latest follow-up. Mean maximal depths of cement penetration were 1.1 mm in group 1 and 4.8 mm in group 2 at three months (P < 0.001). CONCLUSIONS: Our comparative study between the different diameters used during multiple drilling for the tibial sclerotic surface suggests that a multiple drilling technique with a larger diameter of 4.5 mm can improve the depth of cement penetration and reduce the occurrence rate of RLLs after TKAs.