A Novel Spiked Washer and Screw Technique Provides a Biomechanically Superior Posterolateral Corner and Arcuate Fracture Repair.

Posterolateral corner and arcuate fractures can cause significant disruption to the stability and kinematics of the knee. This study aimed to determine the biomechanical performance of a novel spiked washer (SW) and intramedullary screw technique compared with a tension slide technique (TST) for the repair of arcuate fractures. Sixteen matched fresh-frozen cadaver knees underwent repair. Each specimen underwent transection of the posterolateral corner and lateral capsule along with a proximal fibula osteotomy to simulate an arcuate fracture. Eight specimens underwent repair with a SW technique and 8 underwent repair with a TST. Each specimen underwent cyclic loading followed by load to failure. Gap formation, ultimate load to failure, energy to failure, and stiffness were assessed. The SW technique had significantly less gap formation and higher load to failure. Furthermore, the SW technique had significantly higher stiffness and energy to failure. A SW and screw technique provided a significantly stronger construct with less gap formation when compared with a TST. [Orthopedics. 202x;4x(x):xx-xx.].

A Patella-Sided Tensioning Technique for Medial Patellofemoral Ligament Reconstruction.

Reconstruction of the medial patellofemoral ligament (MPFL) is a common procedure for treatment of recurrent patellofemoral instability. Over the last two decades, multiple surgical techniques for MPFL reconstruction have been described with no clear consensus on a superior reconstruction technique. Appropriate graft tensioning is one of the most important factors for a successful MPFL reconstruction. Overtensioning of the MPFL graft can lead to patellofemoral joint overload and undertensioning can lead to recurrent instability. Current literature demonstrates descriptions of MPFL reconstruction with final graft tensioning performed off of the femoral side. We describe a technique in this article for performing final graft tensioning from the patellar side, which gives the surgeon an option for intraoperative tension adjustments after evaluating patellar tracking.

Local Zinc Chloride Release From a Calcium Sulfate Carrier Enhances Fracture Healing.

BACKGROUND: This study examined the efficacy of calcium sulfate (CaSO4) as a carrier for intramedullary delivery of zinc chloride (ZnCl2) to treat fracture healing in a BB Wistar rat model. A non-carrier-mediated injection of 3.0 mg/kg of ZnCl2 has previously been shown to enhance fracture healing. METHODS: A heterogeneous mixture of ZnCl2 and CaSO4 was administered into the intramedullary femoral canal and a mid-diaphyseal femur fracture was created unilaterally. Early and late parameters of fracture healing were assessed using biomechanical testing, radiographic scoring, quantitative histomorphometry (for percentage of new cartilage and bone within the fracture callus), and long-term histologic evaluation. RESULTS: Fractures treated with 1.0 mg/kg of ZnCl2/CaSO4 demonstrated a significantly higher maximum torque to failure compared with both CaSO4 (P = 0.048) and saline (P = 0.005) controls at 4 weeks postfracture (396.4 versus 251.3 versus 178.7 N mm, respectively). Statistically significant increases in torsional rigidity, effective shear modulus, and effective shear stress were also found, as well as a 3.5 times increase in radiographic score (based on bone union). Histologic examination of the fracture callus indicated enhanced chondrogenesis at day 14 postfracture, with increased percent cartilage for the ZnCl2/CaSO4 group compared with saline (P = 0.0004) and CaSO4 (P = 0.0453) controls. Long-term radiographic and histologic evaluation revealed no abnormal bone formation or infection up to 12 weeks postoperatively. CONCLUSIONS: The effective dose of ZnCl2 augmentation for the enhancement of fracture healing in rats was reduced 3-fold in this study compared with previous findings. Furthermore, CaSO4 acted synergistically with ZnCl2 to increase the mechanical strength and stability at the fracture site.

Orthobiologics in Foot and Ankle Surgery.

Exploration into the molecular aspects of the healing process has led to the development of autologous and recombinant biologic agents. These products, collectively known as orthobiologics, have the potential to optimize favorable outcomes with respect to bone and soft-tissue restoration and to maximize the natural healing response. These orthobiologics include platelet-derived growth factor, bone morphogenetic proteins, and platelet-rich plasma. Although the usefulness of these growth factors is well described in various fields of surgery, few data exist to support or oppose the specific application of growth factors in foot and ankle surgery.

Local manganese chloride treatment accelerates fracture healing in a rat model.

This study investigated the effects of local delivery of manganese chloride (MnCl2), an insulin-mimetic compound, upon fracture healing using a rat femoral fracture model. Mechanical testing, histomorphometry, and immunohistochemistry were performed to assess early and late parameters of fracture healing. At 4 weeks post-fracture, maximum torque to failure was 70% higher (P<0.05) and maximum torsional rigidity increased 133% (P<0.05) in animals treated with 0.125 mg/kg MnCl2 compared to saline controls. Histological analysis of the fracture callus revealed percent new mineralized tissue was 17% higher (P<0.05) at day 10. Immunohistochemical analysis of the 0.125 mg/kg MnCl2 treated group, compared to saline controls, showed a 379% increase in the density of VEGF-C+ cells. In addition, compared to saline controls, the 0.125 mg/kg MnCl2 treated group showed a 233% and 150% increase in blood vessel density in the subperiosteal region at day 10 post-fracture as assessed by detection of PECAM and smooth muscle α actin, respectively. The results suggest that local MnCl2 treatment accelerates fracture healing by increasing mechanical parameters via a potential mechanism of amplified early angiogenesis leading to increased osteogenesis. Therefore, local administration of MnCl2 is a potential therapeutic adjunct for fracture healing.