Posterior Cervical Screw System


The CastleLoc-S Posterior Cervical System is a top-loading, simple, and secure system for rigid fixation. CastleLoc-S includes instrumentation and spinal implants for posterior spinal fixation for the cervical and upper levels of the thoracic spine (C1-T3). Spinal implants are available in polyaxial screws, reduction polyaxial screws, partially threaded screws, straight and curved rods, set screws, hooks and hook set screws. Various types of accessories included in CastleLoc-S such as crosslinks, angled/ parallel/ axial rod-to-rod connectors, and lateral connectors (with and without stoppers), offer surgeons options to tackle any type of complexities. All products are made of titanium alloy (Ti-6Al-4V ELI/ in conformance with ASTM F136), approved for medical use.


  • Top-loading polyaxial screws with friction heads enable quick and simple constructed assembly
  • Self-tapping flute centers screws for easy insertion
  • Low-profile screw head
  • Two diameters with cancellous profile (3.5 mm & 4.0 mm rescue screw) 3.5 mm diameter rod
  • 3.5 mm and 4.0 mm cancellous screws offer up to 45° angulation pre-cut and pre-contoured rods eliminate the need to cut and contour rods in the operating room
  • Instrumentation designed for both MIS and open procedures


CastleLoc-S Posterior Cervical Screw System implants are intended to provide stabilization as an adjunct to fusion when used with autogenous bone graft or allograft following reduction of fractures/ dislocations or trauma in the spine. The hooks and rods are intended to provide stabilization to promote fusion following reduction of fracture/ dislocation or trauma in the cervical/ upper thoracic (C1-T3) spine. The pedicle screws are limited to placement in T1-T3 in treating thoracic conditions only. The pedicle screws are not intended to be placed in or to treat conditions involving the cervical spine. CastleLoc-S Posterior Cervical Screw System is indicated for patients with:

  • Degenerative Disc Disease (as defined by neck pain of discogenic origin with degeneration of the disc confirmed by patient history and radiographic studies)
  • Spondylolisthesis
  • Trauma (i.e. fractures or dislocations)
  • Tumors
  • Deformity (defined as kyphosis, lordosis, or scoliosis)
  • Failed Previous Fusion
  • Spinal Stenosis


  • Infection (systemic, spinal or localized)
  • Morbid obesity
  • Signs of local inflammation
  • Fever or leukocytosis
  • Metal sensitivity/ allergies to the implant materials
  • Any medical or surgical condition which would preclude the potential benefit of spinal implant surgery such as the elevation of sedimentation rate unexplained by other diseases, elevation of white blood cell (WBC) count, or a marked left shift in the WBC differential count
  • Grossly distorted anatomy due to congenital abnormalities
  • Rapid joint disease, bone absorption, osteopenia, and/or osteoporosis
    • *Osteoporosis is a relative contraindication since this condition may limit the degree of obtainable correction, the amount of mechanical fixation, and/or the quality of the bone graft
  • Any case not needing a bone graft and fusion or where fracture healing is not required
  • Any case requiring the mixing of metals from different components
  • Any patient having inadequate tissue coverage over the operative site or where there is inadequate bone stock, bone quality, or anatomical definition
  • Any case not descried in the indications
  • Any patient unwilling to cooperate with the postoperative instructions
  • Any time implant utilization would interfere with anatomical structures or expected physiological performance

Important Note

Before using a product placed on the market by L&K Biomed, the operating surgeon should study carefully the following recommendations, warnings and instructions, as well as the available product-specific information (e.g., product literature, written surgical technique). L&K Biomed is not liable for complications arising from the use of the device outside of its indicated uses, surgical technique or judgment, product selection, and similar matters outside the control of L&K Biomed.

Compatibility between all L&K Biomed Spine product lines, including acquisitions of pre-existing product lines, has not been established. Only authorized combinations of products should be used. Only use as indicated in the Instructions for Use (Package Insert) and/or the Surgical Technique.

General Conditions of Use

  1. The implants must be implanted only by surgeons having undergone the necessary training in spinal surgery. Their use in implantation must be decided upon in accordance with the surgical and medical indication, the potential risks and limitations related to the this type of surgery, the contra-indications, side effects, and precautions defined, and in the knowledge of the nature and metallic, metallurgic and biological characteristics of the implants to be used.
  2. It is recommended theCastleLoc-S Posterior Cervical System should not be used together with implants from a different source, a different manufacturer, or made from a different material. If this should occur, L&K BIOMED Co., Ltd. declines all responsibility.
  3. Under no circumstances may the implants be re-used; although the device may appear infect on removal, internal modifications due to the stresses and strains placed on it, or small defects may exist, which may lead to the fracture of the implant

Potential Adverse Effects and Complications

  1. Bending, loosening or fracture of the implants or instruments
  2. Loss of fixation
  3. Sensitivity to a metallic foreign body, including possible tumor formation
  4. Skin or muscle sensitivity in patients with inadequate tissue coverage over the operative site, which may
    result in skin breakdown and/or wound complications
  5. Nonunion or delayed union
  6. Infection
  7. Nerve or vascular damage due to surgical trauma, including loss of neurological function, dural tears,
    radiculopathy, paralysis and cerebral spinal fluid leakage
  8. Gastrointestinal, urological and/or reproductive system compromise, including sterility, impotency and/or loss
    of consortium
  9. Pain or discomfort
  10. Bone loss due to resorption or stress shielding, or bone fracture at, above or below the level or surgery
    (fracture of the vertebra)
  11. Hemorrhage of blood vessels and/or hematomas
  12. Malalignment of anatomical structures, including loss of proper spinal curvature, correction, reduction and/
    or height
  13. Bursitis
  14. Bone graft donor site pain
  15. Inability to resume activities of normal daily living
  16. Reoperation
  17. Death


    An explanted metal implant should never be reimplanted. Even though the device appears undamaged, it may have small defects and internal stress patterns which may lead to early breakage.
    Contouring of metal implants should be done only with proper equipment. The operating surgeon should avoid
    any notching, scratching or reverse bending of the devices when contouring. Alterations will produce defects in surface finish and internal stresses that may become the focal point for eventual breakage of the implant.
    Titanium alloy components should never be bent sharply or reverse bent. If a construct is over-contoured it is recommended that a new construct is contoured correctly rather than reverse bending the over-contoured construct.
    If the device is not removed after the completion of its intended use, any of the following complications may occur: (1) Corrosion, with localized tissue reaction or pain; (2) Migration of implant position resulting in injury; (3) Risk of additional injury from post-operative trauma; (4) Bending, loosening, and/or breakage, which could make removal impractical or difficult; (5) Pain, discomfort, or abnormal sensations due to the presence of the device; (6) Possible increased risk of infection; and (7) Bone loss due to stress shielding. The surgeon should carefully weigh the risks versus benefits when deciding whether to remove the implant. Implant removal should be followed by adequate postoperative management to avoid refracture or deformity. If the patient is older and has a low activity level, the surgeon may choose not to remove the implant thus eliminating the risks involved in a second surgery.

Adequately Instruct the Patient

Post-operative care and the patient’s ability and willingness to follow instructions are among the most important aspects of successful bone healing. The patient must be made aware of the limitations of the implant, and instructed to limit and restrict physical activities, especially lifting and twisting motions and participating in any type of sports. The patient should understand that a metallic implant is not as strong as normal healthy bone and could loosen, bend and/or break if excessive demands are placed on it, especially in the absence of complete bone healing. Implants displaced or damaged by improper activities may migrate and damage the nerves or blood vessels. An active, debilitated, or demented patient who cannot properly use weight supporting devices may be particularly at risk during postoperative rehabilitation.


When using metallic surgical implants, the surgeon should be aware of the following:

  • The correct selection of the implant is extremely important. The potential for success is increased by the selection of the proper size, shape and design of the implant. The size and shape of the human spine presents limiting restrictions of the size and strength of implants. No implant can be expected to withstand the unsupported stresses of full weight bearing.
  • The surgeon must ensure that all necessary implants and instruments are on hand prior to surgery. The device must be handled and stored carefully, protected from damage, including corrosive environments. They should be carefully unpacked and inspected for damage prior to use.
  • Correct handling of the implant is extremely important. Contouring of the metal devices is to be avoided.
  • All implants and instruments must be cleaned and sterilized prior to surgery.
  • Mixing of dissimilar metals can accelerate the corrosion process. Stainless steel and titanium implants must NOT be used together. The CastleLoc-S Posterior Cervical System should not be used with components from any other system or manufacturer.
  • As with all orthopaedic implants, the CastleLoc-S Posterior Cervical System should never be reused under any circumstances.
  • Proper implant selection and patient compliance to postoperative precautions will greatly affect surgical outcomes. Patients who smoke have been shown to have an increased incidence of nonunion. Therefore, these patients should be advised of this fact and warned of the potential consequences.
  • Postoperative care is important. The patient should be instructed in the limitations of his/her metallic implant and should be cautioned regarding weight bearing and body stress on the appliance prior to secure bone healing.
  • Correct handling of the implant is extremely important. Contouring of the metal devices is to be avoided.
  • The CastleLoc-S Posterior Cervical System has not been evaluated for safety and compatibility in the MR environment. The LnK Cervical Fixation system has not been tested for heating or migration in the MR environment.

Packaging, Labeling, and Storage

  1. The implants are supplied non-sterile.
  2. The implants are delivered in packages; these must be intact at the time of receipt. All the legal information required for this type of implants is given on the label of each package.
  3. The implants may be delivered as a complete set: implants and instrumentation are set out on specially designed trays in boxes which can be sterilized directly.
  4. Use care in handling and storage of implant components. Cutting, sharply bending, or scratching the surface can significantly reduce the strength and fatigue resistance of the implant system. This, in turn, could induce cracks and/or non-visible internal stresses that could lead to fracture of the implants. Implants and instruments in storage should be protected from corrosive environments such as salt air, moisture, etc. Inspection and trial assembly are recommended prior to surgery to determine if instrument components or implants have been damaged during storage or prior procedures.
  5. CastleLoc-S Posterior Cervical System is non-sterile medical devices (implants & instrumentation) must be cleaned and sterilized before use according to the procedures detailed below.

Sterilization Procedures

All implants and instruments used in surgery must be sterilized by the hospital prior to use. Remove all packaging materials prior to sterilization. Only sterile products should be placed in the operative field. See recommended procedure in the product manual.