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Hardware Removal: Tips And Pearls For Difficult Screws
Removal of hardware for patients is often necessary and, in our experience, typically leads to high patient satisfaction, especially in cases of prominent hardware. Frequently, the procedure execution is rapid with no hindrance. The basic planning behind the surgical procedure seems simple; pick the correct instrumentation and remove the hardware. However, one may certainly encounter issues along the way, resulting in cases that do not go as smoothly or as quickly as initially planned. A complicated hardware removal can be unpredictable and frustrating. For this reason, adapting and being prepared for the unknown is extremely important.
Understanding The Role Of Preoperative Planning
The importance of preparation for a hardware removal cannot be understated. X-rays with multiple views may help one to better understand the position, angle and structural integrity of the hardware. Whenever possible, obtaining the operative report from the initial surgery can aid in planning. It is important to know the implant manufacturer, implant type, time of implantation, material (steel, titanium), screw head recess geometry (hexagonal, star or cruciform) and screw measurements. Having alternative tools on standby with a pre-emptive plan for complications will reduce the chances of a drastic prolongation of time spent in the operating room.
Intraoperative Adaptations To Consider
In the operating room, careful dissection while protecting vital structures can identify and expose the hardware designated for removal. One should remove all soft tissue or bony overgrowth surrounding the hardware for adequate visualization prior to attempting engagement of the removal device. Often, we find a dental pick or a #15 blade can remove soft tissue from within a screw head. If using a screwdriver, it is important to fully engage into the screw head prior to removal and properly align with the screw axis to prevent stripping. To improve grip on the screw, one may use a mallet to drive the screwdriver deeper into the screw recess. Additionally, to initiate screw removal, we recommend turning the screwdriver clockwise for a half turn and then counterclockwise. Constant pressure and proper counter-pressure are necessary throughout screwdriver rotation to avoid slippage and potentially stripping the screw head. Even one event of slippage can halve the subsequent maximal torque values of turning the screw in clockwise and counterclockwise directions.1
Stripped Screw Head. If the screw head is stripped and the screwdriver is not engaging into the head of the screw, it is possible to achieve an interference fit by applying gauze around the tip of the screwdriver.2 This will allow for a maximal friction component that translates to the additional torque needed to remove the screw. If required, there are other instruments available to remove a screw with a stripped head. If enough of the screw head is exposed, one may grasp it firmly with pliers and turn it counterclockwise. Specifically, we find using locking pliers can simplify this task.
Several manufacturers include reverse-threaded conical extraction devices in their screw removal sets. One can place the threads of a conical extraction screw in the screw head recess, while applying pressure and turning the device counterclockwise until the extraction screw fully engages the screw head (see first figure above). The surgeon then turns the device further counterclockwise until the screw is removed. To better engage the extraction screw into the screw recess, a mallet can be helpful prior to turning counterclockwise.
Cannulated Screw. One can best assist in removal of a cannulated screw by using the appropriately sized Kirschner wire to identify the trajectory of the screw. If the screw head is intact, then a cannulated screwdriver over the Kirschner wire will allow an attempt at removal of the screw. If a broken cannulated screw is lodged in bone, a reverse-threaded conical extraction device inserted in the hollow shaft of the screw and turned counterclockwise, will engage and turn until the screw is fully removed.
Additional techniques descriptions are relevant specifically for difficult cannulated screw removal in the case of subtalar joint arthrodesis. Matson and colleagues3 describe a more minimal approach compared to the above techniques. In the situation that the screw is spinning in place, one can insert a Kirshner wire under fluoroscopic guidance in the posterior aspect of the screw and advance until it exits the skin anteriorly. Careful dissection down to bone on the anterior aspect is necessary where the Kirschner wire exits. The surgeon places a cannulated drill and appropriately sized soft tissue protector over the wire and drill the bone until reaching the distal-most aspect of the screw. Then the drill can be disengaged from the power source, leaving the drill bit in place. A mallet used on the drill bit, pushes the screw posteriorly through the soft bone until it can be grasped with a hemostat or pliers.
Similar to this method, Melvin and team4 describe a technique for removal of cannulated screws from the ankle syndesmosis, in which a K-wire guides the cannulated drill for entry at the medial tibia. The drill bit is kept on the power source and used as a reverse screwdriver when it engages the cutting tip of the screw and powered forward. The authors advocate that, in their experience this technique lowers risk of fracture and saves more bone than with the use of a hollow reamer.
Broken Screw. Removing hardware is more difficult when the screw head or shaft is broken below the cortical surface of the bone. Often, deep broken hardware can be ignored as it will not irritate surrounding soft tissues. However, in cases of infection, non-union or revisional surgeries, the deep hardware may require removal. For broken screw shafts near the surface, in the authors’ experience, a gouge can be helpful to remove the surrounding bone and expose enough of the screw shaft so that it may be grasped with pliers and carefully removed. For deeper screws, a hollow reamer can be used in line with the long axis of the screw until the reamer advances about five mm over the broken screw (see second figure above). Following exposure of the screw shaft, an extraction bolt placed over the screw will engage the screw via reversed threads. While maintaining axial pressure, the surgeon turns the engaged extraction bolt counterclockwise, causing the screw shaft to turn. One continues this counterclockwise turning until the screw is completely removed (see third figure above). If the extraction bolt is not getting the necessary grip on the screw shaft, it may be necessary to use a hollow reamer to drill further over the screw to attain enough exposure. If achieving proper grip remains difficult, it may be necessary to ream to the far cortex. The screw is then easily removed with any device of the surgeons choosing to grip and remove the reamed cylindrical bone containing the screw.
Cold-Welded Screw. Locking plate technology has created some concerns with screws cold welding to the plate, especially in the case of titanium screws, due to the soft nature of that metal.5 Screw head stripping may happen more easily in cold-welded screws due to higher torque requirements. If the screw cannot be removed with a screwdriver or reverse-threaded conical extraction device, a diamond cutting wheel can cut the plate adjacent to the difficult screw to remove the newly segmented plate (see fourth figure above). This will leave an isolated screw easily removable by pliers. The cutting wheel can also cut the plate while leaving a holdable fragment still attached to the screw, which can then remove the plate fragment and screw as a unit using pliers (see fifth figure above). In especially stubborn cases, one can obliterate the jammed screw head to free the plate using a carbide drill bit. One must protect the soft tissue with the carbide drill bit, as many small pieces of metal may deposit there. The best way to protect the area of interest is to put saline-soaked gauze on the surrounding soft tissue prior to drilling. The authors recommend constant irrigation and suction during the drilling process. Once the screw head is destroyed by the carbide drill bit, the plate is easily removed, and the remaining screw shaft can be extracted with pliers.
Concluding Comments
Hardware removal surgeries are straightforward in terms of the surgeon’s goals of treatment, but these cases can produce many complexities in completing the surgery successfully. Often these cases are very quick and uneventful, but they can be the exact opposite, which requires the surgeon to be well-prepared for any unexpected issues that arise. Preoperative planning for these cases with correct instrumentation available cannot be understated as it will help to decrease operating room time and avoid frustration. When the hardware removal is complicated, these tips and pearls should help guide surgeons on what steps to take next to have a successful removal.
Dr. Gorski is a Diplomate of the American Board of Podiatric Medicine and practices with Denver Health Orthopedics in Denver, Colo.
Dr. Gill recently completed residency at the Denver VA Health Care System in Denver, Colo.
Dr. Hoffman is a Fellow of the American College of Foot and Ankle Surgeons and practices with Denver Health in Denver, Colo.
1. Behring JK, Gjerdet NR, Mølster A. Slippage between screwdriver and bone screw. Clin Orthop Rel Res. 2002;(404):368-372.
2. Bhutta MA, Dunkow PD, Lovell ME. A simple technique for removal of screws with damaged heads. Ann Royal Coll Surg Eng. 2003;85(3):207.
3. Matson AP, Shi GG, Parekh SG. Technique tip: the use of cannulated drill as a tamp to remove loose cannulated screws. Foot Ankle Spec. 2016;9(4):342-344.
4. Melvin JS, Downing KL, Ogilvie CM. A technique for removal of broken cannulated tricortical syndesmotic screws. J Orthop Traum. 2008;22(9):648-651.
5. Georgiadis G, Gove N, Smith A, Rodway I. Removal of the less invasive stabilization system. J Orthop Traum. 2004;18(8):562-564
6. Hak DJ, McElvany M. Removal of broken hardware. J Am Acad Orthop Surg. 2008;16(2):113-120.
