Guoqing Cui

Septic Arthritis After Arthroscopic Anterior Cruciate Ligament Reconstruction: A Retrospective Analysis of Incidence, Presentation, Treatment, and Cause

PURPOSE The purpose of this report is to summarize our experience in the diagnosis and management of septic arthritis after anterior cruciate ligament (ACL) reconstruction. METHODS A retrospective review was conducted of all the arthroscopic ACL reconstructions performed at our institution between 1997 and 2007. Postoperative septic arthritis occurred in 21 of 4,068 patients. The incidence, cause, presentation, laboratory results, and treatment of all infected patients were analyzed. RESULTS The incidence of septic arthritis after ACL reconstruction was 0.52%. The most common symptoms of the infected patients were fever, swelling, severe pain, tenderness, and restricted motion. The erythrocyte sedimentation rate, C-reactive protein level, and fibrinogen level were markedly elevated. Microbiology showed that coagulase-negative Staphylococcus was the most common bacterium. Both conservative and operative treatments were effective, and no patient had the ACL graft removed. However, the conservative group had a longer recovery time and duration of intravenous antibiotic therapy. CONCLUSIONS Septic arthritis after arthroscopic ACL reconstruction is a rare but potentially devastating complication. The correct diagnosis relies on clinical evaluation, laboratory tests, synovial fluid analysis, and bacterial culture. With early diagnosis and prompt treatment, the infection can be successfully eradicated. Our proposed treatment protocol is arthroscopic debridement and irrigation as quickly as possible, with retention of the ACL graft when it is still functional. LEVEL OF EVIDENCE Level IV, therapeutic case series.

The protective effect of tetramethylpyrazine on cartilage explants and chondrocytes

AIMS OF STUDY Ligusticum wallichi Franchat (chuanxiong) is a very common traditional Chinese herbal medicine in China. Tetramethylpyrazine (TMP) is a major active ingredient extracted from Ligusticum wallichi Franchat. We investigated the protective effect of TMP on interleukin-1β (IL-1β) induced proteoglycan (PG) degradation and apoptosis in rabbit articular cartilage and chondrocytes. MATERIALS AND METHODS Rabbit articular cartilage explants and chondrocytes were cultured with 10 ng/ml IL-1β for 72 h in the absence or presence of various concentrations of TMP (50, 100 or 200 μM). Cartilage and chondroprotective effects of TMP were determined by evaluating (1) the degree of PG degradation by measuring the amount of glycosaminoglycan (GAG) released into the culture media with 1,9-dimethylmethylene blue (DMMB) assay in cartilage explants; (2) gene expression of MMP-3 and TIMP-1 by real-time quantitative reverse transcription-polymerase chain reaction analysis in cartilage explants; (3) chondrocytes viability with MTT assay; (4) the production of intracellular reactive oxygen species (ROS) with laser scanning confocal microscopy (LSCM). Anti-apoptotic effects of TMP were determined by measuring (1) apoptosis with flow cytometric analysis; (2) mitochondrial membrane potential assay with LSCM; (3) caspase-3 activity with special assay kit. RESULTS IL-1β treatment increased the level of GAG released into the culture media, and induced the gene expression of MMP-3 and inhibited the gene expression of TIMP-1 in cartilage explants. Moreover, IL-1β treatment decreased the cell viability and mitochondrial membrane potential, and enhanced the level of intracellular ROS, apoptosis rate, and caspase-3 activity in chondrocytes. However, simultaneous treatment with TMP attenuated the IL-1β-induced cartilage and chondrocyte destruction in a dose-dependent manner. TMP showed the decrease of GAG degradation and MMP-3 mRNA production, and the enhancement of TIMP-1 mRNA production in cartilage explants. TMP also increased the cell viability in chondrocytes. Furthermore, TMP inhibited the chondrocytes apoptosis through suppression of ROS production, maintaining of mitochondrial membrane potential and downregulation of caspase-3 activity. CONCLUSION These results demonstrate that TMP has the cartilage and chondroprotective effect, which suggest that TMP could act as an agent for pharmacological intervention in the progress of OA.

Effect of repeated freezing–thawing on the Achilles tendon of rabbits

The increased use of allograft tissue in the reconstruction of anterior cruciate ligament has brought more focus to the effect of storage and treatment on allograft. The purpose of this study was to observe the effect of histology and biomechanics on Achilles tendon in rabbits through repeated freezing–thawing before allograft tendon transplantation. Rabbit Achilles tendons were harvested and processed according to the manufacture’s protocol of tissue bank, and freezing–thawing was repeated three times (group 1) and ten times (group 2). Those received only one cycle were used as controls. Then, tendons in each group were selected randomly to make for histological observations and biomechanics test. Histological observation showed that the following changes happened as the number of freezing–thawing increased: the arrangement of tendon bundles and collagen fibrils became disordered until ruptured, cells disrupted and apparent gaps appeared between tendon bundle because the formation of ice crystals. There were significant differences between the experimental and control groups in the values of maximum load, energy of maximum load and maximum stress, whereas no significant differences existed in other values such as stiffness, maximum strain, elastic modulus, and energy density. Therefore, repeated freezing–thawing had histological and biomechanical effect on Achilles tendon in rabbits before allograft tendon transplantation. This indicates that cautions should be taken in the repeated freezing–thawing preparation of allograft tendons in clinical application.

C-Reactive Protein and Erythrocyte Sedimentation Rate Changes After Arthroscopic Anterior Cruciate Ligament Reconstruction: Guideline to Diagnose and Monitor Postoperative Infection

PURPOSE The purposes of our study were to determine normative C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) values from a retrospective review of patients with and without infection after anterior cruciate ligament (ACL) reconstruction and to determine CRP and ESR threshold levels that can serve as diagnostic indicators of infection. We also tried to draw a curve of CRP and ESR value changes after treatment of ACL infection to evaluate the response to treatment of the infection. METHODS A retrospective chart review was performed of arthroscopic ACL reconstruction patients from 2007 to 2008 (noninfection group) and all patients with postoperative intra-articular infection from 1997 to 2010 (infection group). We collected the CRP and ESR values on the third and fifth postoperative days in the noninfection group and before infection treatment and on the first, third, fifth, seventh, 10th, 14th, 21st, 28th, and 35th days after infection treatment in the infection group. Sensitivity, specificity, and Youdens index were calculated for different threshold values of CRP and ESR as predictors of infection. Receiver operator curves were obtained for CRP and ESR on the fifth postoperative day. RESULTS Of 122 patients, 83 had normal joints and 39 had septic joints. The mean CRP and ESR values in patients with septic joints were 101.9 mg/L and 57.1 mm/h, respectively, which were significantly higher than those in the noninfection group (P < .01). A CRP value of 41 mg/L and ESR value of 32 mm/h were the optimal thresholds to predict an infection, which had the highest Youdens index of all calculated values and had sensitivity values of 94.1% and 91.2%, respectively, and specificity values of 97.6% and 80.5%, respectively. The peak CRP level after infection treatment occurred earlier than the peak ESR level (first day v third day) and returned to normal more quickly (21st day v 28th day). CONCLUSIONS Both CRP and ESR were helpful in determining the presence of a normal or septic joint. The threshold values of 41 mg/L for CRP and 32 mm/h for ESR had the most optimal sensitivity and specificity. The peak CRP level occurred earlier than the peak ESR level after treatment of postoperative infection and returned to normal more quickly. In this study CRP was more useful than ESR to evaluate the response of infection to treatment. LEVEL OF EVIDENCE Level IV, diagnostic study.

Comparison Between Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction With 6- to 8-Stranded Hamstring Autograft A Prospective, Randomized Clinical Trial

Background: Whether double-bundle (DB) anterior cruciate ligament (ACL) reconstruction with 6- to 8-stranded hamstring autograft (HG) is better than single-bundle (SB) ACL reconstruction remains debatable, as long-term follow-up data are lacking. Purpose: To prospectively investigate and compare the long-term results of DB and SB ACL reconstruction with a 6- to 8-stranded HG. Study Design: Randomized controlled clinical trial; Level of evidence: 1. Methods: A total of 80 patients with chronic ACL rupture were randomized to SB or DB ACL reconstruction with a 6- to 8-stranded HG. In the SB group, both the semitendinosus tendon (ST) and the gracilis tendon (GT) were prepared in 3 or 4 strands, with a total of 6 to 8 strands. In the DB group, the ST was prepared in 3 or 4 strands used for the anteromedial bundle, and the GT was prepared in the same manner for the posterolateral bundle. Each graft was fixed with an EndoButton, a bioabsorbable interference screw, and a staple. Outcome assessment was performed by a blinded independent observer using International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores, as well as range of motion (ROM), Lachman test, pivot-shift test, KT-2000 arthrometer side-to-side difference, and return-to-sport data. Results: A total of 68 patients (DB group, 34; SB group, 34) were observed for a mean of 80 months (range, 74-86 months). There were 2 traumatic instability failures and two 5° extension restrictions in the DB group, while no failures or 5° extension restrictions were observed in the SB group. The mean Lysholm, Tegner, and IKDC scores improved significantly in both groups compared with preoperation scores (P < .05). No patient had a positive Lachman test result. No significant differences were found between groups in functional scores, incidence of pivot shift, ROM, Lachman test, KT-2000 arthrometer anterior laxity, or time and level of return to sport. Conclusion: Both SB and DB ACL reconstruction with 6- to 8-stranded HG showed satisfactory results in subjective scores and anteroposterior and rotational stability over a nearly 7-year follow-up; neither technique was superior.

The Position of the Posterolateral Bundle Femoral Tunnel During Arthroscopic Double-Bundle Anterior Cruciate Ligament Reconstruction: A Cadaveric Study

PURPOSE The purpose was to find a simple guideline to help establish accurate positioning of the posterolateral bundle (PLB) femoral bone tunnel during double-bundle anterior cruciate ligament reconstruction by measuring the distance between the center of the PLB femoral footprint to the shallow and the deep articular cartilage borders of the lateral wall of the intercondylar notch. METHODS The femoral insertions of the anteromedial bundle and PLB of the anterior cruciate ligament were dissected in 22 male cadaveric knees, aged 25 to 45 years. By use of the intercondylar notch as the landmark, the distances between the center of the PLB femoral footprint and the shallow and the deep articular cartilage borders of the lateral wall of the intercondylar notch were measured with the knees flexed at 90°. The measured data (mean ± standard deviation) were evaluated and compared. RESULTS The center of the PLB was positioned 8.60 ± 1.52 mm and 8.65 ± 1.54 mm from the shallow and the deep cartilage borders of the lateral wall of the intercondylar notch, respectively (P = .95). The distance between the center of the PLB footprint to the low cartilage border of the lateral intercondylar wall was 5.05 ± 0.76 mm. CONCLUSIONS The findings suggest that the position of the center of the PLB femoral footprint is at the middle of the line joining the shallow and the deep borders of the femoral cartilage. CLINICAL RELEVANCE Surgeons can use our results as a guideline and use the PLB footprint remnant as a reference at the same time to locate the femoral PLB tunnel in a simple, easy, and repeatable way.

The Hug-up Test: A New, Sensitive Diagnostic Test for Supraspinatus Tears

Background:The supraspinatus tendon is the most commonly affected tendon in rotator cuff tears. Early detection of a supraspinatus tear using an accurate physical examination is, therefore, important. However, the currently used physical tests for detecting supraspinatus tears are poor diagnostic indicators and involve a wide range of sensitivity and specificity values. Therefore, the aim of this study was to establish a new physical test for the diagnosis of supraspinatus tears and evaluate its accuracy in comparison with conventional tests. Methods:Between November 2012 and January 2014, 200 consecutive patients undergoing shoulder arthroscopy were prospectively evaluated preoperatively. The hug-up test, empty can (EC) test, full can (FC) test, Neer impingement sign, and Hawkins-Kennedy impingement sign were used and compared statistically for their accuracy in terms of supraspinatus tears, with arthroscopic findings as the gold standard. Muscle strength was precisely quantified using an electronic digital tensiometer. Results:The prevalence of supraspinatus tears was 76.5%. The hug-up test demonstrated the highest sensitivity (94.1%), with a low negative likelihood ratio (NLR, 0.08) and comparable specificity (76.6%) compared with the other four tests. The area under the receiver operating characteristic curve for the hug-up test was 0.854, with no statistical difference compared with the EC test (z = 1.438, P = 0.075) or the FC test (z = 1.498, P = 0.067). The hug-up test showed no statistical difference in terms of detecting different tear patterns according to the position (&khgr;2 = 0.578, P = 0.898) and size (Fishers exact test, P > 0.999) compared with the arthroscopic examination. The interobserver reproducibility of the hug-up test was high, with a kappa coefficient of 0.823. Conclusions:The hug-up test can accurately detect supraspinatus tears with a high sensitivity, comparable specificity, and low NLR compared with the conventional clinical tests and could, therefore, improve the diagnosis of supraspinatus tears in clinical settings.