Is Prophylactic Antibiotic Use Necessary Before Dental Procedures in Primary and Revision TKA? A Propensity Score-matched, Large-database Study.

BACKGROUND: The question of whether dental procedures increase the risk of periprosthetic joint infection (PJI) in patients who have undergone total joint arthroplasty (TJA) remains controversial. QUESTIONS/PURPOSES: (1) Are dental procedures associated with an increased incidence of PJI in the setting of either primary or revision TKA after controlling for relevant potentially confounding variables? (2) Is the administration of prophylactic antibiotics before dental procedures associated with any differences in this risk? (3) Which factors are associated with increased incidence of PJI after dental procedures? METHODS: This nationwide, retrospective, comparative, large-database study evaluated 591,602 patients who underwent unilateral primary or revision TKA between 2009 and 2019 using the Health Insurance Review and Assessment Service data in South Korea, in which all people in South Korea were registered and to which all medical institutions must charge any procedures they performed. The study population was divided into 530,156 patients with dental procedures and 61,446 patients without dental procedures based on whether the patients underwent a dental procedure at least 1 year after the index surgery. After propensity score matching, patients were classified into a dental (n = 182,052) and a nondental cohort (n = 61,422). The dental cohort was then divided into two groups: 66,303 patients with prophylactic antibiotics and 115,749 patients without prophylactic antibiotics based on prophylactic antibiotic use. After propensity score matching, patients were categorized into prophylactic (n = 66,277) and nonprophylactic (n = 66,277) cohorts. Propensity score matching was used to control for covariates including posttraumatic arthritis associated with PJI risk according to the dental procedure and prophylactic antibiotic use among the cohorts. After propensity score matching, the standardized mean difference was confirmed to be less than 0.1 for all variables. Kaplan-Meier survival analyses, log-rank tests, and Cox proportional hazards regression analysis was performed. RESULTS: Dental procedures were not associated with an increase in PJI risk after primary (adjusted HR 1.56 [95% CI 0.30 to 8.15]; p = 0.60) or revision TKA (adjusted HR 1.74 [95% CI 0.90 to 3.34]; p = 0.10). Additionally, use of prophylactic antibiotics was not associated with a reduced PJI risk after the index surgery, either for primary (adjusted HR 1.28 [95% CI 0.30 to 5.42]; p = 0.74) or revision TKA (adjusted HR 0.74 [95% CI 0.45 to 1.23]; p = 0.25). Although surgery type and prophylactic antibiotic use exhibited no influence on PJI occurrence after dental procedures, posttraumatic arthritis was associated with PJI. The adjusted HR for posttraumatic arthritis was 4.54 (p = 0.046). CONCLUSION: Our findings suggest that dental procedures were not associated with an increased risk of PJI for up to 2 years after the dental procedure in patients who underwent either primary or revision TKA. Based on these findings, there is insufficient rationale for the use of prophylactic antibiotics before dental procedures in patients who have undergone primary or revision TKA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Analysis of radiographic factors affecting the significant differences in knee alignment between hip-to-talus and hip-to-calcaneus radiographs after opening-wedge high tibial osteotomy.

BACKGROUND: Optimal alignment after opening-wedge high tibial osteotomy (OWHTO) is crucial for obtaining good clinical results. A hip-to-calcaneus radiograph (HCR) appears to reflect the true mechanical axis. However, no study has been reported using the HCR in patients who underwent OWHTO. We aimed to analyze the radiographic factors affecting the significant difference in the weight-bearing line (WBL) ratio between two radiographs after opening-wedge high tibial osteotomy (OWHTO). METHODS: This retrospective study included 51 patients who underwent both hip-to-talus radiographs (HTR) and HCR after OWHTO. The patients were divided into two groups; a consistent group (WBL ratio difference between postoperative HTR and HCR < 5%; N = 35) and an inconsistent group (> 5%; N = 16). Radiographic variables for lower extremity alignment, knee and ankle joints, and clinical scores were evaluated. The receiver operating characteristic curve was used to determine the threshold of radiographic variables that induced inconsistencies between the two radiographs. RESULTS: The mean postoperative WBL ratio in the HCR of the inconsistent group was significantly higher than that of the consistent group (57.7 ± 13.2% and 49.1 ± 11.6%, respectively) (P = 0.02). The preoperative and postoperative ankle joint line obliquity (AJLO) and preoperative lateral distal tibia ground surface angle (LDTGA) were significantly different between the two groups (P < 0.05). The preoperative AJLO (odds ratio 0.784, confidence interval 0.655-0.939, P = 0.008) significantly affected WBL ratio inconsistency. The cutoff value of the preoperative AJLO was 3.16°. However, clinical scores did not differ significantly between the two groups. CONCLUSION: The pre-and postoperative AJLO and the preoperative LDTGA were significantly different between the two groups. Among these variables, only preoperative AJLO negatively affected the inconsistency in WBL ratios between the two radiographs (HTT and HTC). Therefore, it should be considered to prevent postoperative overcorrection of the true mechanical axis after OWHTO, even though we corrected it properly. Level of evidence Level IV.

Therapeutic Nanodiamonds Containing Icariin Ameliorate the Progression of Osteoarthritis in Rats.

In present study, icariin (ICA)/tannic acid (TA)-nanodiamonds (NDs) were prepared as follows. ICA was anchored to ND surfaces with absorbed TA (ICA/TA-NDs) and we evaluated their in vitro anti-inflammatory effects on lipopolysaccharide (LPS)-activated macrophages and in vivo cartilage protective effects on a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA). The ICA/TA-NDs showed prolonged release of ICA from the NDs for up to 28 days in a sustained manner. ICA/TA-NDs inhibited the mRNA levels of pro-inflammatory elements, including matrix metalloproteinases-3 (MMP-3), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), and increased the mRNA levels of anti-inflammatory factors (i.e., IL-4 and IL-10) in LPS-activated RAW 264.7 macrophages. Animal studies exhibited that intra-articular injection of ICA/TA-NDs notably suppressed levels of IL-6, MMP-3, and TNF-α and induced level of IL-10 in serum of MIA-induced OA rat models in a dose-dependent manner. Furthermore, these noticeable anti-inflammatory effects of ICA/TA-NDs remarkably contributed to the protection of the progression of MIA-induced OA and cartilage degradation, as exhibited by micro-computed tomography (micro-CT), gross findings, and histological investigations. Accordingly, in vitro and in vivo findings suggest that the prolonged ICA delivery of ICA/TA-NDs possesses an excellent latent to improve inflammation as well as defend against cartilage disorder in OA.

Safety and effectiveness of intra-articular injection of a highly cross-linked hyaluronic acid, LBSA0103 (Synovian): Results from a post-marketing surveillance study in South Korea.

This study aimed to assess the safety and effectiveness of the highly cross-linked hyaluronic acid-LBSA0103-in patients with knee osteoarthritis (OA) as per the prescribing information (PI) in South Korea. A total of 3,140 subjects aged ≥19 years were enrolled in this post-marketing surveillance (PMS) study from 2013 to 2019. The subjects received one or two injections of LBSA0103. The median duration of follow-up was 308 days. Adverse events (AEs), adverse drug reactions (ADRs), and serious AEs (SAEs) were monitored. Effectiveness was evaluated based on an index of effectiveness in accordance with the guidelines established by the Ministry of Food and Drug Safety and using a 100-mm visual analog scale (VAS) for weight-bearing pain. Overall, 250 subjects (7.96%) experienced 292 AEs and of these, unexpected AEs occurred in 114 subjects (3.63% [95% CI: 3.00-4.35]). Injection site pain was the most frequent AE reported by 81 subjects (2.58% [95% confidence intervals (CI): 2.05-3.20]). One hundred subjects experienced 108 ADRs (3.18% [95% CI: 2.60, 3.86]) and 15 unexpected ADRs were experienced by 13 subjects (0.41% [95% CI: 0.22-0.71]). Seventeen subjects experienced 22 SAEs (0.54% [95% CI: 0.32-0.87]) during the entire PMS period, and all were considered "unlikely" related to the study drug. Most AEs were mild in terms of severity and resolved during the study period. LBSA0103 was also effective in relieving symptomatic pain in knee OA patients. The condition in more than 80% of the subjects was considered to be improved when assessed by the investigators. LBSA0103 resulted in a significant reduction in the mean VAS score at 12 weeks after the first and second injections (24.79 (± 20.55) mm and 17.63 (±12.31) mm, respectively; p<0.0001). In conclusion, LBSA0103, used for the treatment of knee OA in a real-world setting, was well tolerated, with an acceptable safety profile and consistent therapeutic effect.

In Vitro Anti-Inflammatory and Antioxidant Activities of pH-Responsive Resveratrol-Urocanic Acid Nano-Assemblies.

Inflammatory environments provide vital biochemical stimuli (i.e., oxidative stress, pH, and enzymes) for triggered drug delivery in a controlled manner. Inflammation alters the local pH within the affected tissues. As a result, pH-sensitive nanomaterials can be used to effectively target drugs to the site of inflammation. Herein, we designed pH-sensitive nanoparticles in which resveratrol (an anti-inflammatory and antioxidant compound (RES)) and urocanic acid (UA) were complexed with a pH-sensitive moiety using an emulsion method. These RES-UA NPs were characterized by transmission electron microscopy, dynamic light scattering, zeta potential, and FT-IR spectroscopy. The anti-inflammatory and antioxidant activities of the RES-UA NPs were assessed in RAW 264.7 macrophages. The NPs were circular in shape and ranged in size from 106 to 180 nm. The RES-UA NPs suppressed the mRNA expression of the pro-inflammatory molecules inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in a concentration-dependent manner. Incubation of LPS-stimulated macrophages with RES-UA NPs reduced the generation of reactive oxygen species (ROS) in a concentration-dependent manner. These results suggest that pH-responsive RES-UA NPs can be used to decrease ROS generation and inflammation.

Analysis of correlation between the consumption of beverages and the risk of radiographic knee osteoarthritis in Korean people: A cross-sectional study using the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-1, 2).

The purposes were to analyze correlations between the frequency of beverage drinking (coffee, green tea, milk, and soft drinks) and the presence of radiographic knee osteoarthritis (OA) in relation to sex. We performed this study using the Korea National Health and Nutrition Examination Survey (KHANES V-1, 2). We examined data from 5503 subjects after exclusion. We utilized the food frequency questionnaires from KHANES, and reorganized them into 2 or 3 groups according to the frequency of beverage consumption. We analyzed the relationship between radiographic knee OA and beverage consumption statistically after adjusting confounding factors with multivariable logistic regression analysis. Knee OA was inversely associated with coffee consumption only in women (P < .05). The odds ratio of knee OA was lower in those who drank at least a cup of coffee than in those who did not drink coffee in women (P for trend < .05). However, there was no significant linear trend of the odds ratio of each group in both sexes for drinking other beverages. As the coffee consumption increased, the radiographic knee OA group showed decreasing linear trend only in women. However, other beverages did not show a significant relation to the radiographic knee OA in both sexes.

Accelerated Versus Non-accelerated Rehabilitation After Primary Anterior Cruciate Ligament Reconstruction Using Hamstring Autografts: A Systematic Review and Meta-analysis of Comparative Studies.

PURPOSE: This study aimed to compare the clinical outcomes between accelerated rehabilitation (AR) and non-accelerated rehabilitation (NR) after anterior cruciate ligament reconstruction (ACLR) using hamstring autografts through a systematic review and meta-analysis. METHODS: To compare the outcomes between AR and NR, we searched Medline, Embase, and the Cochrane Library. Studies comparing their clinical outcomes after ACLR using hamstring autografts were included. AR was characterized by the starting range of motion and weight-bearing within 3 days and return to sports within 6-9 months. A meta-analysis of clinical outcome parameters used in ≥ 3 studies was conducted. RESULTS: Seven studies were included. The International Knee Documentation Committee subjective score was significantly higher in AR than in NR at the 3- (mean difference [MD], 7.30; 95% confidence interval [CI] 1.55-13.05; P = 0.013) and 6-month follow-ups (MD, 5.64; 95% CI 0.11-11.17; P = 0.046). The side-to-side difference in anterior tibial translation at the final follow-up assessed in four studies was significantly lower in NR than in AR (MD, 0.59; 95% CI 0.12-1.07; P = 0.015). Overall Tunnel widening at the final follow-up assessed in four studies was also smaller in NR than in AR (MD, 0.48; 95% CI 0.00-0.96; P = 0.0479). However, the mean side-to-side difference and overall tunnel widening between them was < 1 mm. CONCLUSION: The early subjective clinical outcomes of AR after ACLR using hamstring autografts were superior to those of NR. Although tunnel widening and anterior instability were also significantly larger in AR than in NR, the difference was not clinically relevant.

Biomechanical Difference between Conventional Transtibial Single-Bundle and Anatomical Transportal Double-Bundle Anterior Cruciate Ligament Reconstruction Using Three-Dimensional Finite Element Model Analysis.

The purpose of our study was to analyze the graft contact stress at the tunnel after transtibial single-bundle (SB) and transportal double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. After transtibial SB (20 cases) and transportal DB (29 cases) ACL reconstruction, the three-dimensional image of each patient made by postoperative computed tomography was adjusted to the validation model of a normal knee and simulated SB and DB ACL reconstructions were created based on the average tunnel position and direction of each group. We also measured graft and contact stresses at the tunnel after a 134 N anterior load from 0° to 90° flexion. The graft and contact stresses became the greatest at 30° and 0° flexion, respectively. The total graft and contact stresses after DB ACL reconstruction were greater than those after SB ACL reconstruction from 0° to 30° and 0° to 90° knee flexion, respectively. However, the graft and contact stresses of each graft after DB ACL reconstruction were less than those after SB ACL reconstruction. In conclusion, the total graft and total contact stresses after DB ACL reconstruction are higher than those after SB ACL reconstruction from 0° to 30° and 0° to 90° knee flexion, respectively. However, the stresses of each graft after DB ACL reconstruction are about half of those after SB ACL reconstruction.

Hip-to-calcaneus alignment differs from hip-to-talus alignment in patients with genu varum deformity.

PURPOSE: To (1) compare the weight-bearing line (WBL) ratios of the knee joints measured using the conventional (hip-to-talus radiographs, HTRs) and novel (hip-to-calcaneus radiographs, HCRs) orthoradiograms, (2) compare the hip-knee-ankle (HKA) angle between cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms, and (3) investigate the optimal cutoff value (COV) of the HKA angle causing inconsistency in the orthoradiograms. METHODS: Sixty limbs of 31 patients with HTR and HCR records were retrospectively reviewed. After drawing the mechanical axis on each radiograph, the WBL ratios of the knees were calculated and compared between the conventional and novel orthoradiograms. In subgroup analysis, cases with < 5% and > 5% differences in WBL ratios between two orthoradiograms were classified as consistent and inconsistent groups, respectively. Receiver operating characteristic curve based on the HKA angles of the lower limbs was used to identify the COV causing the inconsistency between the orthoradiograms. RESULTS: Inter- and intra-rater reliabilities of all radiologic measurements were > 0.75. The WBL ratios showed no significant difference between the two orthoradiograms. However, the HKA angle was significantly larger in the inconsistent group than in the consistent group (7.0° ± 1.8° vs. 4.4° ± 2.5°; P < 0.001). The COV of the HKA angle that caused inconsistency in the two orthoradiograms was 4.0° (area under the curve, 0.774). CONCLUSION: The hip-to-calcaneus alignment differed significantly from the hip-to-talus alignment in patients with genu varum deformity. HCR measurement can be a complementary method for planning corrective osteotomy for patients with genu varum deformity. LEVEL OF EVIDENCE: IV.

Change in the weight-bearing line ratio of the ankle joint and ankle joint line orientation after knee arthroplasty and high tibial osteotomy in patients with genu varum deformity.

PURPOSE: Several studies reported that excessive correction of severe genu varum deformity with total knee arthroplasty or high tibial osteotomy (HTO) could result in ankle joint pain and osteoarthritis progression. However, few studies have evaluated the change in the weight-bearing-line (WBL) ratio of the ankle joint after knee arthroplasty or HTO in patients with genu varum deformities. This study aimed to investigate the change in the WBL ratio of the ankle joint and ankle joint line orientation after knee arthroplasty or HTO in patients with genu varum deformities. METHODS: We retrospectively evaluated 40 patients (mean age, 69.9 ± 8.0 years) with genu varum deformities of > 5° and underwent knee arthroplasty or HTO. Three radiologic parameters, including (1) the hip-knee-ankle (HKA) angle, (2) WBL ratio of the ankle joint, and (3) ankle joint line orientation relative to the ground (AJLO-G), were assessed using pre-operative and post-operative orthoradiographs. A paired t test was used to evaluate post-operative changes in the three parameters. Correlations between the change in HKA angle and that in the WBL ratio of the ankle joint and AJLO-G were analyzed. RESULTS: The mean HKA angle significantly decreased post-operatively (10.6° ± 5.3° to 1.1° ± 3.4°; P < 0.001). The WBL ratio of the ankle joint increased from 35.8% ± 15.2% to 53.0% ± 17.4% (P < 0.001), with a lateral shift of the mechanical axis. The AJLO-G decreased with valgization of ankle orientation (7.8° ± 4.8° to 0.4° ± 3.8°; P < 0.001). The change in the HKA angle was significantly correlated with that in the AJLO-G (correlation coefficient = 0.716; P < 0.001) but not with the change in the WBL ratio of the ankle joint. CONCLUSION: Knee arthroplasty and HTO corrected the genu varum deformity, which influenced the lateral shift of the WBL of the ankle joint and valgization of the ankle joint line orientation.

Enhanced tendon restoration effects of anti-inflammatory, lactoferrin-immobilized, heparin-polymeric nanoparticles in an Achilles tendinitis rat model.

Gradual wear and tear can cause a local inflammatory response in tendons. The trauma and inflammatory reaction eventually impair the biomechanical properties of the tendon. In this study, we prepared lactoferrin-immobilized, heparin-anchored, poly(lactic-co-glycolic acid) nanoparticles (LF/Hep-PLGA NPs) and evaluated their in vitro anti-inflammatory effects on interleukin-1ß (IL-1ß)-treated tenocytes and in vivo tendon healing effects in a rat model of Achilles tendinitis. Long-term LF-deliverable NPs (LF/Hep-PLGA NPs) remarkably decreased mRNA levels of pro-inflammatory factors [cyclooxygenase-2 (COX-2), IL-1ß, matrix metalloproteinase-3 (MMP-3), MMP-13, IL-6, and tumor necrosis factor-α (TNF-α)] and increased mRNA levels of anti-inflammatory cytokines (IL-4 and IL-10) in both IL-1ß-treated tenocytes and the Achilles tendons of a collagenase-induced Achilles tendinitis rat model. Interestingly, anti-inflammatory LF/Hep-PLGA NPs greatly enhanced collagen content, mRNA levels of tenogenic markers [collagen type I (COL1A1), decorin (DCN), tenascin-C (TNC)], and biomechanical properties such as tendon stiffness and tensile strength. These results suggest that anti-inflammatory LF/Hep-PLGA NPs are effective at restoring tendons in Achilles tendinitis.

Epidemiology of Bearing Dislocations After Mobile-Bearing Unicompartmental Knee Arthroplasty: Multicenter Analysis of 67 Bearing Dislocations.

BACKGROUND: This study investigated the epidemiology and causes of bearing dislocations following mobile-bearing unicompartmental knee arthroplasty (MUKA) and determined whether the incidence of primary bearing dislocations decreases as surgeon experience increases. METHODS: We retrospectively reviewed the bearing dislocations following MUKAs performed by 14 surgeons with variable experience levels. Causes of bearing dislocations were determined based on the surgical records, radiographs, and operator's suggestion. Using a chi-squared test, the incidence of bearing dislocation was compared between the first 50, the second 50, and the next 100 unicompartmental knee arthroplasties (UKAs) of each surgeon's cohort. RESULTS: There were 67 (3.6%) bearing dislocations from 1853 MUKAs. The mean time to bearing dislocations after index MUKAs was 33 months (range, 1-144 months); 55% of the bearing dislocations occurred within 2 years after the index MUKAs. Primary bearing dislocations (n = 58) were the most common, followed by secondary (n = 6) and traumatic dislocations (n = 3). There was no significant difference in the incidence of bearing dislocation between the first 50 and second 50 UKAs for each surgeon. Two surgeons showed a significant decrease in bearing dislocations in their second 100 UKAs, while the other surgeons did not show a difference between their first 100 and second 100 UKAs. CONCLUSION: Most bearing dislocations after MUKAs were related to technical errors such as component malposition or gap imbalance. This study did not confirm that the incidence of bearing dislocations decreases as the number of cases increases. LEVEL OF EVIDENCE: IV, Case series.

Biomaterials for the Treatment of Tendon Injury.

Background: Most tendon injuries are occurring from a gradual wearing and tearing of the tendon tissues from overuse. Such injuries are usually seen in sports, exercising, or daily activities that involve a high mechanical load and weight bearing. However, owing to the lack of both cellularity and blood vessels in tendons, the process of tendon repair is slow and inefficient. Although various conservative (non-surgical) and surgical management options are conducted by the clinicians, a gold standard of these approaches does not exist. In this regard, the treatment of tendon injuries is challenging. Method: Here, we describe the recent advances of biomaterial-based approaches for the treatment of injured tendons. Results: Regenerative medicine is an emerging multidisciplinary research that specializes in the repair of damaged tendon tissues through the delivery of regenerative factors by biomaterials. Conclusion: Although current biomaterial-based treatment strategies have shown their potential for tendon healing, future research and clinical applications should focused on finding the optimum combinations of regenerative factors with ideal biomaterials for the repair of tendons.

Arthroscopic Treatment of Popliteal Cysts with and without Cystectomy: A Systematic Review and Meta-Analysis.

PURPOSE: To compare the clinical outcomes of the arthroscopic treatments for popliteal cysts with and without cystectomy. METHODS: PubMed/MEDLINE, EMBASE, KoreaMed, and Cochrane Library were searched from the earliest available date of indexing through August 2016. The methodological quality of all articles was assessed according to the Coleman methodology score (CMS). Studies were grouped according to the surgical method, and a meta-analysis was conducted to identify the unsuccessful clinical outcome and complication rates. RESULTS: Nine studies were included; the mean CMS was 67.33 (standard deviation, 8.75 points). Cystectomy was reported in five studies; cystectomy was not performed in four studies. The odds ratio of unsuccessful clinical outcomes evaluated by Rauschning and Lindgren score was 122.05 (p<0.001) with cystectomy and 58.12 (p<0.001) without cystectomy. The effect size of complications was 0.16 (p<0.001) with cystectomy and 0.03 (p<0.001) without cystectomy. The recurrence rate was 0% with cystectomy and 6.4% without cystectomy. CONCLUSIONS: All the currently available studies showed satisfactory outcomes in both with and without cystectomy groups. However, arthroscopic cystectomy concurrently performed with management of intra-articular lesions was associated with a relatively low recurrence rate and a relatively high incidence of complications.

High incidence of subsequent re-operation following treatments for medial meniscus tears combined with anterior cruciate ligament reconstruction: second-look arthroscopic study.

BACKGROUND: The Multicenter Orthopaedic Outcomes Network (MOON) group recently reported that medial meniscus (MM) repairs are associated with more frequent re-operations when compared to lateral meniscus (LM) repairs. The purpose of this study was to compare the meniscal healing and the incidence of subsequent re-operation of medial and lateral meniscal tears that occurred concurrently with anterior cruciate ligament (ACL) injuries. METHODS: We retrospectively reviewed patients who underwent second-look arthroscopy after primary ACL reconstruction (ACLR) between June 2005 to December 2016. The healing of meniscal tears following repair or left in situ, and re-tear following partial meniscectomy, were evaluated via second-look arthroscopy and compared between medial and lateral meniscus. Moreover, the incidence of subsequent meniscal re-operation after the index ACLR were investigated and compared between medial and lateral meniscus. Subsequent meniscal re-operation was performed in cases of the following three symptomatic meniscus tears: re-tears at the meniscectomy site; new tears; and failed healing of repaired or left in situ meniscus. RESULTS: There were 148 meniscal tears in 121 patients at index ACLR. There were 62 MM tears, 38 LM tears, and 24 bilateral meniscus tears. At second-look arthroscopy, the "successful healing" rate for tears following repair was higher in LM tears (91.2%) compared to MM tears (80.0%), although it was not statistically significant (p > 0.05). No significant differences were observed in the healing of left in situ tears or re-tear of meniscectomy site between medial and lateral meniscus. Patients with MM tears combined with ACL injuries had a higher incidence of subsequent meniscal re-operation compared to patients with LM tears (25.6% vs 16.1%, p = 0.025). CONCLUSIONS: There was a trend for the successful healing rate to be higher in LM repairs than MM repairs. Subsequent meniscal re-operations after ACLR were more frequent in patients with medial meniscal tears concurrently with ACL injuries in comparison to patients with lateral meniscal tears. LEVEL OF STUDY: Level IV, retrospective case series.

Editorial Commentary: Lateral Hinge Fracture After Opening Wedge High Tibial Osteotomy With Long Locking Plate Use.

Lateral hinge fracture (LHF) is a common complication after opening wedge high tibial osteotomy. Such a fracture can be caused by many factors such as osteotomy level, amount of opening, hinge position, and kind of plate. In particular, long locking plates have superior biomechanical stability in cases of LHF compared with short plates. Therefore, these long locking plates should be used in cases of LHF after opening wedge high tibial osteotomy.

A Retrospective Comparison of Union Rates After Open Wedge High Tibial Osteotomies With and Without Synthetic Bone Grafts (Hydroxyapatite and ß-tricalciumphosphate) at 2 Years.

PURPOSE: To evaluate the clinical and radiological results of no bone graft (NBG) after opening wedge high tibial osteotomy (OWHTO) with a locking plate and to compare the bone union rate between the synthetic bone graft (SBG) group and the NBG group after OWHTO using serial radiographs. METHODS: From 2012 to 2015, OWHTOs were performed with SBG or without bone graft using long locking plates. Inclusion criteria were: (1) OWHTO for disease of the medial compartment with varus deformity, and (2) minimum 2-year follow-up and radiographs taken serially to 2 years. Exclusion criteria were: (1) follow-up period <2 years (n = 8) or (2) absence of at least 1 radiograph taken at each follow-up point (n = 14). We retrospectively reviewed radiographs taken preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Groups comprised those filled with a synthetic bone [hydroxyapatite (HA) and ß-tricalciumphosphate (TCP), n=33, SBG group] or without a bone graft (n = 38, NBG group). We compared bone union rate between the 2 groups by measuring the union zone from zone 1 to zone 5 in serial radiographs using Fisher's exact test. RESULTS: OWHTO was performed in a total of 93 knees and 71 knees were included in this study. Both groups showed good clinical and radiological results without correction loss at 2 years. The entire NBG group and 93.9% of the SBG group showed union over zone 3 at 2 years. However, the NBG group showed significantly more incorporation than the SBG group at 6 months (P = .006), 1 year (P = .0003), and 2 years (P = .0003). CONCLUSIONS: Union without correction loss was obtained after OWHTO without bone graft. The NBG group showed significantly more incorporation than the SBG group (HA and ß-TCP) within 2 years. LEVEL OF EVIDENCE: Level IV, case series.

Comparison of Clinical Results, Second-Look Arthroscopic Findings, and MRI Findings Between the Transportal and Outside-In Techniques for Double-Bundle Anatomic Anterior Cruciate Ligament Reconstruction: A Prospective, Randomized Controlled Trial With a Minimum 2-Year Follow-up.

BACKGROUND: Although image analysis has shown that the outside-in (OI) technique is associated with different femoral tunnel geometry than the transportal (TP) technique in anatomic anterior cruciate ligament (ACL) reconstruction, it is not known whether clinical results differ between the 2 techniques. PURPOSE: To compare clinical results, second-look arthroscopic findings, and magnetic resonance imaging (MRI) findings between the TP and OI techniques in anatomic double-bundle (DB) ACL reconstruction. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: From November 2010 to March 2013, 128 patients were enrolled in this study and were randomly assigned to either the TP group (64 patients) or the OI group (64 patients), and DB ACL reconstructions were performed. At the minimum 2-year follow-up (34.9 ± 10.9 months), 111 patients (86.7%) were evaluated with multiple clinical scores and stability tests (KT-2000 arthrometer, Lachman test, and pivot-shift test). Ninety-three knees were evaluated for graft continuity, graft tension, and synovialization by use of second-look arthroscopy. Seventy-eight knees were evaluated on MRI for graft continuity, femoral graft tunnel healing, and graft signal/noise quotient (SNQ). The primary outcome was KT-2000 arthrometer results. Results were compared between the TP and OI groups. RESULTS: No significant differences were found between the 2 groups in terms of KT-2000 arthrometer results, which was the primary outcome, and other clinical results, with the exception of the postoperative functional test of International Knee Documentation Committee (IKDC) objective score. The ratio of grade A and B on the postoperative functional test of IKDC objective score was significantly larger for the OI group (51/58) than the TP group (36/53) ( P = .005). The second-look arthroscopic findings were not significantly different between the 2 groups in either bundle ( P > .05). In addition, MRI findings did not differ significantly between the 2 groups ( P > .05). CONCLUSION: With the exception of the functional test of IKDC objective score, we found that clinical results, second-look arthroscopic findings, and MRI findings did not differ significantly between the OI and TP techniques for anatomic ACL reconstruction, although femoral tunnel geometries differed significantly between the 2 techniques.

Hamstring autograft maturation is superior to tibialis allograft following anatomic single-bundle anterior cruciate ligament reconstruction.

PURPOSE: Using second-look arthroscopy, graft maturation was investigated and compared between hamstring (HA) autografts and tibialis anterior (TA) allografts after anatomic single-bundle anterior cruciate ligament reconstruction (ACLR). METHODS: Fifty-six patients who underwent second-look arthroscopy after anatomic single-bundle ACLR with either HA autografts (26, HA group) or TA allografts (30, TA group) from 2007 to 2016 were retrospectively reviewed. Graft maturation on second-look arthroscopy was evaluated in terms of four parameters: graft integrity (tear), synovial coverage, graft tension, and graft vascularization. Each parameter received a maximum of two points, depending on the status of the reconstructed graft. The total graft maturation score was calculated as the sum of the parameter scores. The total graft maturation and individual parameter scores were compared between the two groups. RESULTS: The mean time from ACLR to second-look arthroscopy was 22.5 ± 7.8 months. The maturation scores in the HA group were significantly better in terms of graft integrity (p = 0.041), graft tension (p = 0.010), and graft vascularization (p = 0.024), whereas the graft synovial coverage score was not significantly different. The total graft maturation score of the HA group was significantly higher than that of the TA group (6.3 ± 0.4 vs. 4.9 ± 0.3, p = 0.013). CONCLUSIONS: This study shows the superior graft maturation of HA autografts compared with that of TA allografts at a mean follow-up of 22.5 ± 7.8 months after anatomic single-bundle ACLR. When anatomic ACLR using soft tissue graft is planned, HA autograft is recommended rather than soft tissue allograft, especially in young and active patients. LEVEL OF EVIDENCE: Retrospective cohort review, Level III.

Diagnostic Value of Synovial White Blood Cell Count and Serum C-Reactive Protein for Acute Periprosthetic Joint Infection After Knee Arthroplasty.

BACKGROUND: The diagnosis of periprosthetic joint infection (PJI) remains difficult, particularly in acute postoperative stage. The purpose of this study was to investigate the optimal cutoff value of synovial white blood cell (WBC) count, percentage of polymorphonuclear cells, erythrocyte sedimentation rate, and C-reactive protein (CRP) for diagnosing early postoperative infection after knee joint arthroplasty. METHODS: We retrospectively reviewed primary total knee arthroplasties and unicompartmental knee arthroplasties, with a knee aspiration within 3 weeks of surgery, from January 2006 to November 2016. Twelve infected cases and 185 uninfected cases met the inclusion criteria of our study. We compared the laboratory parameters (synovial WBC count, percentage of polymorphonuclear cells, erythrocyte sedimentation rate, and CRP levels) between the 2 groups. Receiver operating characteristic curves were constructed to determine the optimal cutoff values for each parameter. Each parameter was studied to determine its sensitivity, specificity, and positive and negative predictive values (PPV and NPV) in diagnosing acute PJI. RESULTS: There were 2 optimal cutoff values for synovial WBC count and CRP levels. With the cutoff value of synovial WBC set at 11,200 cells/µL, acute PJI could be diagnosed with the highest sensitivity (100%) and specificity (98.9%); with the cutoff value set at 16,000 cells/µL, the best PPV and NPV were found (100% and 99.5%, respectively). Similarly, the CRP level >34.9 mg/L had the best sensitivity (100%) and specificity (90.3%), whereas the CRP level >74.5 mg/L had the best PPV (100%) and NPV (99.2%). CONCLUSION: Synovial WBC count and CRP levels are useful in diagnosing acute PJI between 1 and 3 weeks after primary knee arthroplasty.