78 results about "Spinal cage" patented technology

The invention relates to the technical field of medical instruments, and discloses an additive manufacturing bionic bone trabecula full-porous interbody fusion cage which is applied to spinal fusion surgery and is of a bionic bone trabecula full-porous structure made of medical metal through a laser melting or electron beam melting additive manufacturing technology. The interbody fusion cage comprises a front end face, a rear end face, a first side surface, a second side surface, an upper fusion face and a lower fusion face, the upper fusion face and the lower fusion face make direct contact with a vertebral body end plate of a spine, anti-skid teeth are arranged on the surfaces of the upper fusion face and the lower fusion face, and a bone grafting window penetrating through the upper fusion face and the lower fusion face is formed in the center of the interbody fusion cage. The interbody fusion cage has the structure and mechanical property similar to those of cancellous bone and trabecular bone of a human body, can improve the bone combination area and bone ingrowth space, has excellent initial and long-term stability, and can effectively reduce stress shielding so as to improve the bone fusion capability.

The invention relates to a self-generating interbody fusion cage and a preparation method thereof, the interbody fusion cage comprises a porous tantalum support and bioactive piezoelectric ceramic arranged on the porous tantalum support, and the bioactive piezoelectric ceramic comprises hydroxyapatite and barium titanate; the preparation method comprises the following steps that the porous tantalum support is obtained through 3D printing, assembling positions of the bioactive piezoelectric ceramics are reserved on the upper surface and the lower surface of the porous tantalum support, the bioactive piezoelectric ceramics are embedded into the assembling positions of the upper surface and the lower surface of the porous tantalum support, and the weight ratio of barium titanate to hydroxyapatite is (92-98): (2-8). Compared with the prior art, the vertebral fusion cage has the advantages of promoting vertebral fusion by utilizing mechanical force in a human body to generate electricity, matching mechanical properties of a contact surface of the fusion cage, providing osteogenesis related ions, being relatively good in interface combination and the like.

The invention provides an interbody fusion cage. The interbody fusion cage comprises an upper vertebral plate, a lower vertebral plate and a shell, the driving device comprises a driving rod, and a bevel gear pair is arranged on one side of the driving rod; the transmission bevel gear is meshed with the bevel gear pair; the top of the supporting rod is provided with a first spherical hinge, the first spherical hinge is embedded into the spherical seat of the upper vertebral plate, the outer surface of the supporting rod is provided with a transmission thread, and the bottom of the supporting rod is provided with a second spherical hinge; the sleeve is arranged on the outer surface of the supporting rod in a sleeving mode, and the top of the flexible base abuts against the second spherical hinge. According to the technical scheme, the stress shielding effect in the implanting process of the interbody fusion cage can be effectively achieved, and the technical problem that the interbody fusion cage is attached to the physiological curvature can be effectively solved.

The invention provides an interbody fusion cage and a manufacturing method of the interbody fusion cage. The interbody fusion cage comprises a first end plate assembly, a second end plate assembly and an elastic supporting assembly. The two ends of the elastic supporting assembly are connected with the first end plate assembly and the second end plate assembly respectively. The first end plate assembly comprises an end plate body, a tooth retreating prevention structure and a porous structure, the end face of one end of the end plate body is connected with the elastic supporting assembly, and the end face of the other end of the end plate body is a bearing contact face used for abutting against vertebra tissue; the tooth retreating prevention structure and the porous structure are respectively arranged on the bearing contact surface; the tooth retreating prevention structure protrudes out of the bearing contact surface and is used for being fixedly connected with vertebra tissue; hollowed-out holes are formed in the porous structure and used for allowing a part of growing vertebra tissue to extend into the porous structure. The interbody fusion cage solves the problems that in the prior art, due to the fact that the contact area between an interbody fusion cage and vertebrae is small, postoperative prostheses are prone to disengagement or looseness, end plate sclerotin is damaged, and the fusion efficiency is poor.

The invention discloses a design method of a structural mechanical gradient regulation and control interbody fusion cage for end plate defects. The design method comprises the following steps of data acquisition and model construction; analyzing the shape of the defective end plate; carrying out interface mechanical adaptation design on the defect end plate and the structural gradient fusion cage; performing multi-objective optimization; the invention relates to a 3D printing defect endplate mechanical and biological adaptive spinal fusion cage. The individual end plate defect model can be established according to the difference of different patients, the local elastic modulus of the fusion cage is dynamically adjusted through morphological analysis and typing, the stress conduction height matching with the defect end plate is realized, the settlement risk is reduced, and the fusion effect is improved; by combining the biological adaptation design of the end plate, the pore structure and material characteristics of the fusion cage are optimized, and bone healing is promoted; through the scheme of image analysis, digital design, intelligent optimization and precise manufacturing, a mechanical and biological dual-adaptive fusion cage system solution is provided for a patient with the defect of the end plate.

A guide head and a holding head are arranged at the front end and the rear end of an upper supporting plate and the front end and the rear end of a lower supporting plate respectively, the guide head and the holding head are both in a wedge shape, and the two wedge faces of the guide head and the holding head are in sliding contact fit with the inclined faces of the upper supporting plate and the lower supporting plate respectively. The guiding head and the holding head are driven to be separated and gathered through a thread transmission structure, a nut piece of the thread transmission structure and the guiding head are arranged in a rotation-stopping and movement-stopping mode, a screw piece is matched with the holding head in a rotation-stopping and movement-stopping mode, and the end of a bolt piece is provided with an exposed screwing structure. And a gap which is communicated with the hollow accommodating cavity after the guide head and the holding head are gathered to open the upper supporting plate and the lower supporting plate is formed between the upper supporting plate and the lower supporting plate. An outer frame is not needed, the size is small, lifting can be conducted after implantation, the gap communicated with the hollow containing cavity is formed, the bone can be implanted from the side face after the height is increased, and healing of a diseased part is facilitated.

The invention relates to the technical field of medical instruments, and provides an interbody fusion cage and a vertebra fixing system.The interbody fusion cage comprises a first supporting body, a second supporting body, a connecting piece, an adjusting screw rod, a sliding block and a locking piece, the connecting piece is arranged on the first supporting body, and the connecting piece is hinged to the second supporting body; the adjusting screw rod is rotationally connected with the connecting piece; the sliding block is connected with the adjusting screw rod in a threaded fit mode, and the sliding block is connected with the first supporting body in a sliding mode and abuts against the second supporting body. And the locking piece is arranged at the end part of the adjusting screw rod and is used for embedding a gap between the connecting piece and the adjusting screw rod, so that the connecting piece and the adjusting screw rod are relatively fixed in the circumferential direction. The connecting piece and the adjusting screw rod are relatively fixed in the circumferential direction in an embedding mode, so that positioning of the adjusting screw rod can be achieved, and the loosening situation is avoided; when the adjusting screw rod is driven to rotate through the surgical instrument, due to the fact that a locking piece is not installed, stress detection of the surgical instrument cannot be interfered, and the surgical precision can be guaranteed.

The invention relates to the technical field of medical instruments, and particularly discloses an interbody fusion cage and a preparation method thereof.The preparation method comprises the following steps that S1, a mold matched with the interbody fusion cage in shape is prepared, and a porous aluminum filling body is prepared; s2, the two ends of the mold are filled with porous aluminum material filling bodies, and cavities are formed between the mold and the porous aluminum material filling bodies at the two ends; s3, the mold is filled with PEEK in an injection molding mode, and the cavity and pores of the porous aluminum material filling body are filled with the PEEK; and S4, after the PEEK is cured, removing the mold, and dissolving the porous aluminum filling body by adopting a pickling mode, so that porous PEEK is formed at the two ends of the interbody fusion cage. The porous PEEK structure is prepared in an injection molding mode, and the problem that the technical difficulty is large due to the fact that the porous PEEK structure is prepared in a 3D printing mode is solved.

Provided is a height-adjustable interbody fusion cage, comprising: a first end plate and a second end plate connected to an adjacent spine body; the far-end moving block can be relatively movably fixed in dovetail grooves formed in the far ends of the first end plate and the second end plate; the near-end moving block can be relatively movably fixed in dovetail grooves formed in the near ends of the first end plate and the second end plate; the adjusting component is rotatably fixed on the near-end moving block, is in threaded connection with the far-end moving block and can adjust the distance between the far end and the near-end moving block; a vertical guide portion disposed on the first and second end plates so as to support a load in the length or width direction of the first and second end plates; the vertical guide portion includes: a pair of first vertical guides extending vertically from the first end plate toward the second end plate and having a cross-section extending in one direction; and a pair of second vertical guides in which long hole grooves into which the first vertical guides are inserted are formed, and which restrict the direction of movement in which the first and second end plates approach each other or are separated from each other by sliding with the first vertical guides.

A system and method for spinal fusion that can include: a spinal cage body that includes at least one defined graft window cavity; a plurality of electrodes exposed on the surface of the spinal cage body; control circuitry configured to drive the plurality of electrodes in a stimulation mode; wherein there is at least a targeted osteoinduction region and a targeted non-osteoinduction region that are immediately adjacent to the spinal cage body; and wherein the control circuitry includes configuration to excite the plurality of electrodes during the stimulation mode for generation of a current density in the targeted osteoinduction region and targeted non-osteoinduction region according to targeted levels of bone growth.

The invention provides an endoscopic interbody fusion cage and an adjusting method thereof. The endoscopic interbody fusion cage is characterized in that a plurality of first screw holes are formed in a first vertebral plate; the lifting column comprises a plurality of lifting groups, threads are arranged on the outer surface of the lifting column, and the lifting column is rotatably connected with a first screw hole in the first vertebral plate through the threads; the driving device is a cylinder with threads on the surface; the transmission device comprises a plurality of gear sets with different diameters and tooth numbers, the gear sets are meshed with one another, threaded holes are formed in the centers of gears in the gear sets in a penetrating mode, and the transmission device is connected with the driving device in a meshed mode. One end of the steering device is fixedly arranged at the top of the lifting column; a third screw hole is formed in the second vertebral plate, and the other end of the steering device is fixedly connected with the second vertebral plate through a lead screw. According to the technical scheme, the technical problem that when left-right asymmetric angles exist between the upper vertebral plate and the lower vertebral plate, a traditional symmetric fusion cage cannot achieve mechanical load balanced transmission is effectively solved.

The utility model provides an anti-receding expansion type interbody fusion cage, and relates to the technical field of medical equipment. The interbody fusion cage comprises a tube body and a pull rod. The pull rod comprises a rod body and a limiting block, and the rod body is inserted into the pipe body from one side. A limiting groove is formed in the inner side wall of the tube body, a baffle ring is arranged in the limiting groove, a clamping groove is formed in the rod body, and when the interbody fusion cage is opened, the baffle ring is arranged on the rod body in a sleeving mode and clamped into the clamping groove. According to the anti-receding expansion type interbody fusion cage, the invalid size of the cage after the cage is opened can be reduced, work is reliable, and the rebound risk is reduced.

The invention discloses an expansion type interbody fusion cage applied to a minimally invasive spine surgery, and relates to the technical field of medical instruments, the expansion type interbody fusion cage applied to the minimally invasive spine surgery comprises a fixing frame, an adjustable clamping assembly is rotatably arranged on the inner wall of the fixing frame and used for supporting and fixing the intervertebral space of a patient, and the clamping assembly is used for clamping the intervertebral space of the patient; the stability of the vertebral body is improved; adjusting assemblies capable of sliding are arranged at the two ends of the fixing frame and used for adjusting the height of the clamping assemblies so that the clamping assemblies can be matched with the vertebral gap of the patient. According to the expansion type interbody fusion cage applied to the minimally invasive spine surgery, the rotating frame, the fixing column and the conical nails are matched with one another, the two conical nails are used for adjustment, the interbody fusion cage can be matched with a vertebral body gap of a patient, and therefore the practicability and flexibility of the interbody fusion cage are greatly improved.

The utility model discloses an adjustable implanting device for a visual interbody fusion cage, which comprises a lens implanting assembly and a fusion cage implanting assembly, and is characterized in that the lens implanting assembly comprises a base, a lens channel arranged in the middle of the base, and a water inlet channel and a water outlet channel which are arranged on two sides of the lens channel; the fusion cage imbedding assembly comprises a fixing groove fixedly formed in the upper end of the base, sliding grooves formed in the two sides of the fixing groove, elastic grooves formed in the sliding grooves in a sliding mode, extension grooves formed in the middle of the bottom end of the fixing groove and the middle of the top end of the elastic grooves correspondingly, and extension pieces installed in the extension grooves in a sliding mode. The push-pull plate is arranged at the tail end of the extending piece, the traction holes are formed in the outer side of the bottom end of the fixing groove and the outer side of the top end of the elastic groove, and the traction hooks are detachably connected into the traction holes. A fusion cage channel and an endoscope channel are separated, adjustment can be conducted according to the size of a fusion cage, meanwhile, the fusion cage can be prevented from slipping, and the success rate of fusion cage imbedding is increased.

The invention relates to the technical field of medical instruments, in particular to an interbody fusion cage which comprises an interbody fusion cage body, the interbody fusion cage body is of a polyhedral structure and is implanted into the lumbar intervertebral space through an anterior lateral approach, and a screw channel and a connecting screw opening are formed in the front end position and the rear end position in the length direction of the interbody fusion cage body respectively; the screw channel is used for allowing screws to penetrate through the upper surface and the lower surface of the interbody fusion cage body, connected with the vertebral cancellous bone in a matched mode and fixed to the inner side of the lateral portion of the vertebral cancellous bone. The connecting screw is used for being connected with an installation instrument in a matched mode when the interbody fusion cage is implanted. By means of the screw channel, the fixing capacity of the interbody fusion cage can be effectively improved, better stability can be effectively provided for an OLIF operation through a proper implantation position and screw placement internal fixing operation, the occurrence risk of postoperative internal fixing related complications is effectively reduced, and the safety of the interbody fusion cage is improved. The effectiveness and the safety of the fusion cage in the lumbar vertebra front and outer side approach interbody fusion operation are improved.

Machine learning and intelligent planning techniques are disclosed for fabricating spinal fusion plates and spinal cages that can be utilized as a system together to provide a precision guided anterior cervical discectomy and fusion (ACDF) surgery to a subject in need thereof. The spinal fusion plate provides adjustments of one or more vertebrae even after attaching the plate to the spine of the subject. The spinal fusion plate provides a surgical window or "postbox" for accessing the intervertebral space(s) of the subject, provides the postbox window for precision insertion of a spinal cage, provides a locking inset to prevent over-insertion of the spinal cage, and provides precision compression of the spinal cage after the insertion. Methods of treating subjects in need of a discectomy surgery are described herein utilizing the precision implants.

The invention discloses an interbody fusion cage PET bag and a preparation method thereof.The preparation method comprises the steps that an acid solution or an alkaline solution is adopted for treating the surface of the PET bag, then plasma treatment is conducted on the surface of the PET bag, and the surface-treated PET bag is obtained; placing the PET bag subjected to surface treatment in an NHS solution, carrying out ultrasonic treatment to obtain an activated PET bag, adding the activated PET bag and glycerin into a PBS solution, and carrying out a stirring reaction to obtain a pretreated PET bag; placing the pretreated PET bag and BMP in an NHS solution, and carrying out an ultrasonic reaction to obtain a BMP-fixed PET bag; placing the PET bag fixed with the BMP in a PBS solution for heat treatment; according to the preparation method disclosed by the invention, the biocompatibility and osteoinductivity of the PET capsule are improved, the growth and repair of bone tissues can be promoted, and the problem that the existing PET capsule material is insufficient in bone regeneration efficiency is effectively solved.

The invention relates to the technical field of orthopedic implants, in particular to a 3D printed interbody fusion cage. According to the distraction device, the front end distraction module and the rear end distraction module are arranged, the rear end distraction module is rotationally connected with the upper distraction body and the lower distraction body through the multiple rotating pieces correspondingly, the movement stroke of a first rotating shaft rotationally connected with the rotating pieces is limited through a first limiting sliding groove formed in a linkage piece, and therefore the rear end distraction angle is limited; according to the front end opening module, the movement stroke of a sliding piece on a front end moving piece in the axial direction and the height direction is limited through a second limiting sliding groove obliquely formed in a lower opening body, and therefore linkage adjustment of the angle and the height can be achieved at the same time when the front end is opened; when the first pushing rod and the second pushing rod are driven at the same time, the sliding piece and the second limiting sliding groove are matched, the rotating piece and the rotating shaft are matched, the first limiting sliding groove is matched, and the fourth rotating shaft and the third limiting sliding groove are matched to achieve synchronous opening of the front end and the rear end of the opening body.

The invention relates to an interbody fusion cage and a preparation method thereof, and relates to the field of orthopedic implantation, the interbody fusion cage comprises a vertically placed cylindrical fusion cage main body and a pore structure fixedly connected in an inner hole of the fusion cage main body, and the pore structure is in a lattice net shape. The interbody fusion cage provided by the invention has a bone induction function, so that a good bone fusion effect can be achieved without bone grafting or with a small amount of bone grafting.

An interbody spinal cage when implanted can be manipulated non-invasively to change dimensions conforming to contours of adjacent vertebral bones. The interbody spinal cage includes a flexible shell that encases multiple variable-length rods. Each of the multiple variable-length rods includes telescoping tubes and an actuator for increasing and decreasing the length of the telescoping tubes. Each of the variable-length rods includes a retention member to limit movements of the telescoping tubes, wherein the retention member can be engaged and disengaged. Both the retention member and the actuator can be operated from outside the body in which the interbody spinal cage is implanted.

Disclosed is a spinal cage fixable through insertion of bone screws including a cage body, a receiver disposed on a front surface of the cage body and provided with a plurality of screw holes formed therein so that the bone screws pass through the screw holes to be inserted thereinto, and a fixture coupled to the receiver adjacent to the screw holes and configured to selectively block a portion of each screw hole, wherein, when each bone screw enters a corresponding screw hole, a front end of the fixture is moved in an outward direction of the corresponding screw hole, and when insertion of each bone screw into the corresponding screw hole has been completed, the front end of the fixture is moved in an inward direction of the corresponding screw hole to prevent each bone screw from being separated from the corresponding screw hole.

The utility model discloses an adjustable interbody fusion cage which comprises a group of fusion blocks which are symmetrically arranged up and down and further comprises a front propelling block, a rear propelling block and an adjusting assembly, the adjusting assembly is connected with the front propelling block and the rear propelling block and can adjust the distance between the front propelling block and the rear propelling block, and the front propelling block comprises a group of combined plates of the same structure. And the two combined plates are connected through sunk screws. The distance between the upper fusion block and the lower fusion block is adjusted through the arranged adjusting assembly, then the range of the practical gap of the fusion device is adjusted, and continuous height adjustment of the fusion device is achieved. Meanwhile, the bone paste injection channel is arranged, so that the artificial bone paste can be conveniently injected after the fusion cage is implanted, and different amounts of artificial bone paste can be implanted according to different operation conditions.

The invention provides a lumbar vertebra oblique lateral self-locking integrated fusion internal fixation system which comprises an interbody fusion cage, the interbody fusion cage is of a torpedo-shaped streamline structure on the whole and is of an arc-shaped appearance with the middle protruding and the two sides low, the front portion of the interbody fusion cage is high, the rear portion of the interbody fusion cage is low, the side section of the interbody fusion cage is wedge-shaped, and the interbody fusion cage is matched with an intervertebral space structure. A pair of diagonal trusses is fixedly connected in the hollow cavity; the micro side plate is arranged on one side of the interbody fusion cage, the micro side plate and the interbody fusion cage are of a 3D printing integrated structure, a threaded hole and clamping grooves in the two sides are formed in the middle of the micro side plate, and four inclined threaded holes are formed in the four corners of the micro side plate respectively; the number of the fixing screws is four, the fixing screws are connected into the inclined threaded holes through threads respectively, and the four fixing screws are in a multi-axial-direction crossed angulation form. According to the low-incisura, integrated and self-locking novel oblique lateral fusion internal fixation system, internal fixation related complications can be reduced, the operation process in an operation is simplified, the screw placement safety is ensured, and the use experience of the fusion system is improved.

The utility model discloses a cervical vertebra anterior approach interbody 3D printing porous metal integrated fusion device which comprises a fixator and a cervical vertebra interbody fusion cage, the inner side of the fixator is attached to an axis body and connected with the cervical vertebra body through a fixing insertion piece, and the cervical vertebra interbody fusion cage is connected with the inner side of the fixator. In the anterior cervical intervertebral disc resection fusion internal fixation, integration of bone fusion and internal fixation is achieved, so that the success rate of vertebral fusion is increased, the surgical bleeding amount and damage to muscular tissue are reduced, the surgical time is shortened, and a cervical vertebra complex can be safely and effectively fixed and fused.

The utility model discloses an interbody fusion cage, relates to medical instrument technical field, mainly including: support frame and PEEK matrix, support frame includes first splint and second splint, first splint and second splint are arranged opposite to each other for clamping PEEK matrix, and support frame and PEEK matrix abut against each other, the supporting frame is made of a biocompatible material, and a first splint and a second splint of the supporting frame are both located on the outer side of the PEEK matrix and used for making contact with vertebrae. The supporting frame has good biocompatibility, bone grafting fusion can be promoted and the osseointegration effect can be improved after fusion, the supporting frame and the PEEK matrix with the low elastic modulus form the fusion cage, the overall elastic modulus of the fusion cage is moderate, the stress shielding effect can be reduced, and the fusion cage can be used for bone grafting fusion. Therefore, delayed healing and bone mass loss of adjacent segments are avoided.

The utility model discloses the spinal interbody fusion cage of adjustable elastic modulus relates to the orthopedics equipment field, including roof and bottom plate, the roof corresponds with bottom plate, the bottom plate upside fixedly connected with installation component, the roof is installed with a plurality of high elastic modulus pad and low elastic modulus pad through installation component between bottom plate, the installation component includes the locating plate of vertical fixed connection in the bottom plate upside, is established in a plurality of vertical locating slot on the locating plate. Advantageous effects lie in: through the quantity of adjusting high elastic modulus pad and low elastic modulus pad can adjust the elastic modulus of this fusion ware, increase the quantity of high elastic modulus pad, reduce the quantity of low elastic modulus pad, can increase the elastic modulus of this fusion ware, if reduce the quantity of high elastic modulus pad, increase the quantity of low elastic modulus pad, can reduce the elastic modulus of this fusion ware, make this fusion ware can satisfy different patient demand.

The application discloses a degradable spinal fusion cage with a bone inductive microporous structure and belongs to the technical field of orthopedic implant medical devices. The fusion cage is integrally made of a degradable polymer composite material, the inside of the main body is provided with a bionic gradient microporous structure which is interconnected, and the surface of the fusion cage is provided with an active coating layer with a slow-release function. The mechanical property of the product is adapted to the physiological bearing requirement of the spine, the product can be steadily degraded along with the bone tissue regeneration process after being implanted into the human body, can effectively guide the bone tissue and microvessels to grow in, and can improve the intervertebral fusion efficiency; meanwhile, the problems of stress shielding, postoperative infection and the need for secondary removal surgery existing in traditional metal implants are solved, the product has good biocompatibility, the structure is reasonable, the preparation process is simple, and the product is suitable for clinical intervertebral fusion surgery of the spine.

The objective of the present invention is to provide an interbody fusion cage device which: has bone fusion protrusions and bone fusion holes on an upper plate and a lower plate of a cage that is to be inserted between vertebrae, and has a grid-shaped elasticity providing body, formed over both side plates and a rear plate, for adjusting an elastic modulus of the cage to an elastic modulus of a bone such that bone fusion between the vertebrae and the cage is facilitated and subsidence in which the cage penetrates the vertebrae can be prevented; has diagonal screw insertion holes, formed on a front plate of the cage, to be structured such that the insertion direction of fixing screws can be vertically and horizontally adjusted and thus a margin for the direction in which the fixing screw is inserted into the vertebrae from the outside of the cage can be provided, thereby enabling convenience and accuracy of surgery for an operator to be improved; and has a screw fastening hole formed on the front plate of the cage such that a separation prevention screw for preventing the separation of the fixing screw can fastened thereto, and thus the loosening or separation of the fixing screw insertively fastened to the vertebrae from the cage can be prevented.

The utility model discloses a kind of guiding formula arc intervertebral fusion cage sets, it includes: shaft sleeve, intervertebral fusion cage and guide needle, the shaft sleeve includes: first blocking part and second blocking part, the intervertebral fusion cage is housed in the shaft sleeve, the intervertebral fusion cage is configured to rotate radially from the shaft sleeve, the guide needle is configured to pass through the intervertebral fusion cage to guide the intervertebral fusion cage to target position, when carrying out spinal interbody fusion cage fusion, intervertebral fusion cage can be guided to the vertebral body opening of target, is implanted with the rotation to comply with the arc of vertebral body, to avoid injury surrounding nerve root or soft tissue, and reduce the opening area required for operation, reach the requirement of wound range minimization.

An implant for interbody fusion of vertebrae comprising a unibody cage structure having an enveloping cage volume and a minimized material volume. The cage structure comprises a first and a second generally planar ring member, each ring member formed from an opposing pair of lengthwise joists and an opposing pair of cross joists, the joists together forming a large opening through the ring member. The ring members are fixedly sandwiched on a plurality of support members, the support members holding the ring members in a spaced apart relationship to thereby provide a large void volume relative to the enveloping cage volume, to thereby allow for receipt of a large volume of bone graft within the cage structure.