Minwei Cai

Locking Compression Plate and Cerclage Band for Type B1 Periprosthetic Femoral Fractures: Preliminary Results at Average 30-Month Follow-Up

We present results of 12 type B1 periprosthetic femoral fractures treated with locking compression plate and cerclage band from January 2003 to June 2007. The average follow-up was 30.1 months. Twelve fractures united in an average period of 4.8 months. The mean Harris hip score was 84.4. One patient presented with loosening of proximal screws at 5 months. This patient was treated nonoperatively as she had radiographic evidence of fracture union. One patient with delayed union required 9 months to heal. Unfortunately, 1 month later, she sustained a type C fracture during a slipping injury and treated with cast immobilization. The fracture united after 4 months. None had complications of loss of reduction, plate break, and wound infection.

Lactoferrin Inhibits IL-1β-Induced Chondrocyte Apoptosis Through AKT1- Induced CREB1 Activation

Background/Aims: Chondrocyte apoptosis is largely responsible for cartilage degeneration in osteoarthritis (OA). Interleukin-1 beta (IL-1β) is widely used as a chondrocyte apoptosis-inducing agent, while lactoferrin (LF) is an anabolic reagent which has the potential to inhibit chondrocyte apoptosis. We assessed the effects of LF on cartilage degeneration in IL-1β-induced chondrocytes and in a rat model of OA, and explored the potential molecular mechanisms involved. Methods: Human articular chondrocytes (HACs) were treated with IL-1β alone or in combination with LF. MTT and flow cytometric assays were used to detect changes after treatment with LF. Western blotting was used to examine the relevant molecules regulating apoptosis. Results: We found that IL-1β reduced the viability of HACs, whereas 200 μg/mL of LF significantly counteracted the inhibitory effect of IL-1β. LF significantly inhibited IL-1β-induced HAC apoptosis. The protein expression of the apoptotic markers Caspase-3 and PARP was also significantly reduced in the LF treatment group when analyzed by western blotting. Furthermore, we found that LF triggered CREB1 phosphorylation in IL-1β-induced HAC apoptosis through AKT1 signaling. In addition, LF promoted the repair of articular cartilage damage in a rat OA model with elevated p-CREB levels. Conclusions: These studies suggest that LF has an anti-apoptotic effect on IL-1β-induced chondrocytes, and thus may be a promising novel therapeutic agent for OA.

Superior femoral component alignment can be achieved with Oxford microplasty instrumentation after minimally invasive unicompartmental knee arthroplasty

AbstractPurpose Oxford microplasty (MP) instrumentation has been developed to facilitate the reproducible and consistent performance of minimally invasive unicompartmental knee arthroplasty (MI-UKA) operation. The aim of this study was to compare the clinical and radiographic results of two groups of patients implanted using either a conventional instrumentation technique or an MP technique.MethodsA prospective cohort study of 108 knees in 108 patients who underwent an MI-UKA procedure using either conventionally instrumented UKA (CI-UKA) (52 knees of 52 patients) or MP-assisted UKA (MP-UKA) (56 knees of 56 patients). The clinical assessment included the Oxford Knee Score (OKS), the Knee Society Score (KSS), a visual analogue scale (VAS) for pain, and range of motion (ROM). Complications were also recorded.ResultsNo significant differences were observed between the two groups regarding OKS, KSS, VAS, and ROM. There were also no significant differences in terms of mechanical limb alignment and tibia implant alignment. However, the MP-UKA group showed significantly more accurate positioning of the femoral component than the CI-UKA group. Additionally, the MP-UKA group had more femoral prostheses implanted in the “satisfactory” range and fewer “outliers” than the CI-UKA group. No significant difference in complications was noted between the two groups.ConclusionThis study suggested that compared with CI-UKA, MP-UKA provides significant improvements in increasing the accuracy of sagittal and coronal implantation of the femoral component and in reducing the numbers of outliers for femoral prosthetic alignment. It is advocated that the MP system should be considered when MI-UKA is performed.Level of evidenceTherapeutic study, Level IV.

Improvement of femoral component size prediction using a C-arm intensifier guide and our established algorithm in unicompartmental knee arthroplasty: a report from a Chinese population.

BACKGROUND Unicompartmental knee arthroplasty (UKA) is becoming more widely used with the recent increase in popularity of the use of minimally invasive techniques. However, it is difficult to judge about the femoral component size in UKA using preoperative templating digitally or otherwise. Even when using navigation it is impossible to control the femoral component size. The aim of this study is to develop a better pre- or intra-operative measure that will predict femoral component size. METHODS Ninety-two UKA cases were studied from June 2007 to December 2011 with a mean 26-month follow-up. We developed an intra-operative C-arm intensifier guide (CAIG) method for determining femoral size instead of pre-operative templating. The accuracy of prediction of both methods was compared from a review of post-operative radiographs. In addition, we summarized all cases and developed a Chinese algorithm to determine the femoral component size pre-operatively. RESULTS There was a significant difference between templating (59%) and CAIG (92%) method (P=0.0001). In the Chinese algorithm, height based on gender and tibial size both have greater accuracy of prediction (88% and 70.7%) than the Oxford algorithm (51.1% and 59.8%). Component size distribution and optimal tibial/femoral pairing differed from those in the Oxford report. CONCLUSIONS We conclude that the Chinese algorithm can greatly improve the accuracy of prediction of femoral component size. In addition, CAIG-assisted implantation of a UKR is a reliable intra-operative tool and can aid size selection of the femoral component. LEVEL OF EVIDENCE Level III.

Clinical Outcomes and Risks of Single-stage Bilateral Unicompartmental Knee Arthroplasty via Oxford Phase III

Background: Osteoarthritis often affects the joint bilaterally, and the single-stage (SS) unicompartmental knee arthroplasty (UKA) is advantageous in terms of a single anesthesia administration, a short hospital stay, lower medical costs, and enhanced patient convenience. However, the complication risk of SS UKA continues to be debated. The aim of this article was to evaluate the clinical effectiveness, complications, and functional recovery of SS and two-stage (TS) UKA. Methods: From January 2008 to December 2013, we compared a series of 36 SS UKA with 45 TS UKA for osteoarthritis. The mean age was 65.4 years (range: 55–75 years). The mean body mass index was 25.2 kg/m2 (range: 22–29 kg/m2). The pre- and post-operative Oxford Knee Scores (OKSs), complications, operative times, tourniquet times, the amount of drainage, and hemoglobin (Hb) were evaluated. The Chi-square test, Fishers exact test, and paired and grouped t-tests were used in this study. Results: The mean follow-up was 50 months. No complications of death, fat embolism, deep vein thrombosis, and prosthetic infection were reported. Patients who underwent SS UKA had a shorter cumulative anesthesia time (113.5 vs. 133.0 min, P < 0.01). There were no significant variations between the values of the mean tourniquet time, the amount of drainage, pre- and post-operative Hb in the different groups. No patient required a blood transfusion. No statistical differences were found in the complications between two groups (P > 0.05). At the final follow-up, the mean OKS improved from 39.48 ± 5.69 to 18.83 ± 3.82 (P < 0.01), with no statistical differences between the two groups (P > 0.05). Patients who underwent SS UKA had a faster recovery. Conclusions: The single-staged UKA offers the benefits of a single anesthesia administration, reduced total anesthetic time, decreased overall rehabilitation time, and absence of an increase in perioperative mortality or complications compared with the TS bilateral UKA.