Difficulties encountered removing locked plates

A novel model of locking plate and locking spongious screw: a biomechanical in vitro comparison study with classical locking plate

BACKGROUND

Locking plates are commonly used for the fixation of comminuted, periprosthetic and osteoporotic bone fractures. These plates are secured to the bone with screws, creating a stable connection with fixed angle between the plate and the screws. In this biomechanical in vitro study, our aim is to evaluate and compare the novel locking plate-locking spongious screw model with FDA approved classical locking plate.

METHODS

Sawbone PCF-15 osteoporotic bone model was utilized to simulate osteoporotic bone conditions. Two screws were used to attach both the classical locking plate and the novel locking plate-locking spongious screw model to these bone models. The attachment strength of the screws to the bone blocks was measured by pull-out tests.

RESULTS

Novel locking plate-locking spongious screw model exhibited an 84.38% stronger attachment to the osteoporotic bone model compared to the current locking plate model.

CONCLUSIONS

In conclusion, one of the important problems in the locking plates which is the high Pull-out risk of the locking spongious screws can been resolved with our proposed new model and has a chance of having a better purchase especially in osteoporotic bones.

Indications for the removal of implants after fracture healing: A comparison between human and veterinary medicine

Indications for implant removal after fracture healing are still under debate in both human and veterinary medicine. Although hardware removal is a common procedure, it should not be undertaken lightly. Intra and post-operative complications are common and a thorough evaluation of the risks and benefits should be performed. This review aimed to collect and summarise published data on the indications for implant removal in small animals, compare the collected data with human and equine medicine, and investigate the existence of guidelines for this purpose. There is no international consensual agreement for implant removal after fracture healing, neither in small animals nor in human orthopaedics. Decision-making processes are still controversial in some scenarios, thus clear evidence-based protocols for implant removal are needed.

Failure analysis of a locking compression plate with asymmetric holes and polyaxial screws

Locking compression plates (LCP) with asymmetrical holes and polyaxial screws are effective for treating mid-femoral fractures, but are prone to failure in cases of bone nonunion. To understand the failure mechanism of the LCP, this study assessed the material composition, microhardness, metallography, fractography and biomechanical performance of a retrieved LCP used for treating a bone fracture of AO type 32-A1. For the biomechanical assessment, a finite element surgical model implanted with the intact fixation-plate system was constructed to understand the stresses and structural stiffness on the construct. Also, to avoid positioning screws around the bone fracture, different working lengths of the plate (the distance between the two innermost screws) and screw inclinations (±5°, ±10° and ±15°) were investigated. The fracture site of the retrieved LCP was divided into a narrow side and broad side due to the asymmetrical distribution of holes on the plate. The results indicated that the chemical composition and microhardness of the LCP complied with ASTM standards. The fatigue failure was found to originate on the narrow side of the hole, while the broad side showed overloading characteristics of crack growth. When the screws were inserted away from the region of the bone fracture by increasing the working length, the stress of the fixation-plate system decreased. Regardless of the screw insertion angle, the maximum stress on the LCP always appeared on the narrow side, and there was little change in the structural stiffness. However, angling the screws at -10° resulted in the most even stress distribution on the fixation-plate system. In conclusion, the LCP assessed in this study failed by fatigue fracture due to bone nonunion and stress concentration. The narrow side of the LCP was vulnerable to failure and needs to be strengthened. When treating an AO type 32-A1 fracture using an LCP with asymmetrical holes and polyaxial screws, inserting the screws at -10° may reduce the risk of implant failure and positing screws around the fractured area of the bone should be avoided.

Manual extraction is superior to power tools when removing stripped titanium locking screws

INTRODUCTION

Removal of screws from a titanium locking plate is often difficult once the screw has seized and the head is damaged. Such stripped screws are removed with an extraction screw, which can be used manually or on power. We aim to compare the extraction rates using both these methods.

MATERIAL AND METHODS

We used 50, 3.5 mm diameter/20 mm long titanium locking screws. Fourth-generation saw bone models (radii) were used and 3.5 mm locking plates were fixed. The screws were deliberately over tightened and heads were damaged using a carbide drill to mimic stripped, seized screws. A left turn conical extraction screw coupled with a power tool was used for the first 25 screws and extraction screws coupled with a T handle for the remaining 25. A high-definition camera with a 60 fps frame rate was used to record the event. The time taken to remove screws from the plate was recorded.

RESULTS

When the extraction screw was used manually with T handle, we could remove 23 out of 25 screws (92%). When we used the extraction screw along with a power tool, 15 out of 25 (60%) locking screws were successfully removed.

CONCLUSION

We recommend manual extraction with a T handle, rather than a power tool when removing the stripped locking screws (p-value <0.001). We feel that the haptic feedback provided when using manual extraction allows the surgeon to engage the extraction screws onto the damaged heads, thereby improving the extraction rates.

Implant removal of osteosynthesis. Results of a survey among Spanish orthopaedic surgeons

INTRODUCTION

The indications on extraction of osteosynthesis material are not well defined in the current literature deriving in relative indications, depending on experiences, customs or patient's request. The aim of this article is to assess the beliefs, indications, usual practice and perceived complications of surgeons in Spain regarding on extraction of osteosynthesis material.

METHODS

We conducted a questionnaire of 44 questions covering general demographics, general and subjective opinion on implant removal, specific attitudes by implant type and anatomical location, and personal habits.

RESULTS

164 questionnaires were received. The most frequent indications are patellar and olecranon cerclage wires and elastic nails in children. 56% remove the implant at the patient's request, 31% always remove it in children, 28% do it in asymptomatic patients to avoid possible surgical problems, 14% to avoid a possible peri-implant fracture and 9% by simple preference. The most frequent intraoperative complications are surgery longer than expected, bone growth over the implant, rounded screw head core, cold fusion, difficulty in finding the implant and impossibility to remove part of the implant. The most frequent postoperative complication was persistence of symptoms 39.8%.

CONCLUSION

The results provide information to advise the patient regarding the expected clinical outcome and intra and postoperative complications. The surgeon should cautiously indicate extraction in the asymptomatic patient given the high rate of complications.

Arthroscopic-Assisted Removal of Proximal Humerus Locking Plates With Capsular Release Significantly Improves Range of Motion and Function

Purpose

To investigate the clinical outcomes following the arthroscopic removal of proximal humerus locking plates for symptomatic hardware after open reduction and internal fixation (ORIF) of proximal humerus fractures.

Methods

Patients who underwent arthroscopic removal of hardware (ROH) with capsular release due to pain and/or immobility after receiving locking plates to treat proximal humerus fractures from 2009 to 2016 were identified. Operative and clinic records were reviewed to obtain demographic information, concomitant procedures during ROH, and pre- and postoperative active shoulder range of motion. Postoperative patient-reported outcomes included the QuickDASH, PROMIS Pain Intensity, Constant, and University of California, Los Angeles shoulder rating scale.

Results

In total, 88 patients were included. Patients were evaluated at a minimum of 6 weeks postoperatively after ROH. Patients with pre- and postoperative active range of motion values demonstrated significant improvements in mean forward elevation (n = 69; 78.4%; 115.1° to 152.1°, P < .001), abduction (n = 29; 33.0%; 70.9° to 138.7°, P < .001), external rotation (n = 49; 55.7%; 43.7° to 58.6°, P = .012), and internal rotation (n = 45; 51.1%; 25.7° to 61.9°, P < .001). Patients also reported positive patient-reported scores, including the QuickDASH (4.1 ± 7.8), PROMIS Pain Intensity (3.5 ± 0.9), Constant (84.6 ± 10.7), and University of California, Los Angeles shoulder rating scale (33 ± 2.9), which were measured 70.6 ± 26.6 months postoperatively. There were no surgical complications, no arthroscopic cases were converted to open, but 2 reported refractures (2.3%).

Conclusions

Arthroscopic-assisted removal of proximal humerus locking plates significantly improves motion and function while allowing for management of concomitant shoulder pathology and potentially avoiding open surgery complications. Given that patients undergoing this procedure frequently have multiple comorbidities, arthroscopic-assisted removal with smaller incisions may minimize risks while restoring shoulder mobility. Therefore, arthroscopic ROH for patients experiencing symptomatic hardware after ORIF is recommended.

Level of Evidence

Level IV, therapeutic case series.

Plate Removal after Internal Fixation of Limb Fractures: A Retrospective Study of Indications and Complications in 48 Horses

OBJECTIVE

 The aim of this study was to determine the indications for, and complications of, plate removal surgery in horses that underwent internal fixation of limb fractures.

STUDY DESIGN

 Medical records of horses presented to our hospital between 1990 and 2015 for the removal of plates after treatment of limb fractures were reviewed. Data collected at the time of initial presentation, including signalment, history, fracture features and treatment and information about the indications, timing and complications of implant removal were reviewed.

RESULTS

 The most common bones involved were the ulna (n = 19) and third metacarpal and metatarsal bones (n = 14). A total of 63 plates were removed from 48 horses during 53 separate surgeries, and the complication rate was 6/48; six horses had complications related to implant removal, which included persistent infection (n = 1) and refracture (n = 5). Complications related to implant removal were associated with comminuted fractures (p = 0.002), age > 3 years (p = 0.016) and the presence of surgical site infection (p = 0.001).

CONCLUSION

 Plate removal after fracture healing is necessary in patients with implant-associated clinical signs. There is a strong relationship between the complication rate and the degree of comminution of the original fracture, increasing age and the presence of surgical site infection. The surgeon must be aware of these risk factors when planning plate removal.

Hardware considerations in infection and nonunion management: When and how to revise the fixation

The occurrence of both nonunion and fracture-related infection provides challenges for both the patient and the treating orthopaedic surgeon, with the potential need for complex reconstructive procedures to achieve union and/or eradicate infection. In addition to addressing the multiple different factors that often contribute to nonunion, surgeons are often forced to deal with difficult hardware issues at the time of revision surgery including infected hardware, loose or failing hardware, malaligned hardware, or inappropriate hardware constructs. This article reviews common causes of nonunions with emphasis on infection management and provides indications and techniques for hardware removal in the context of an algorithmic approach to nonunion management with illustrative case examples.

New Technique for Removal of Screws With Damaged Heads

Removal of orthopedic implants may sometimes be difficult because of ongrowth of new bone. Titanium screws can become encased or stripped during the process of initial open reduction and internal fixation or at the time of hardware removal. Difficulty in removing screws from a locking plate is particularly well-known. Two patients with tibial and femoral diaphyseal fractures were treated using a locking plate or an intramedullary nail. However, after fracture healing, it was difficult to remove the locking screw or reconstruction screws because of damage to the heads. The stripped reconstruction screw was successfully removed employing the authors' so-called parallel planes technique. In this method, a high-speed diamond-tipped burr is applied to opposite sides of the screw head to form 2 parallel faces located slightly away from the recess of the screw head. The 2 faces can then be grasped solidly with locking pliers, allowing removal of the implant by unscrewing it with a gentle upward pulling action. The locking plate was cut from the plate edge to the edge of the screw hole. While making these radial cuts in the plates, the authors were careful not to extend the blade into the screw head. After removal of the locking plate from the screw, the authors were able to extract the jammed screw uneventfully using this technique. This technique can be performed without difficulty and does not require a special device. It is a useful option for extraction of damaged screws. [Orthopedics. 2017; 40(5):e911-e914.].

Complications during removal of conventional versus locked compression plates: is there a difference?

BACKGROUND

Osteosynthesis plate removal is one of the most commonly performed procedures in orthopaedic surgery. Due to technological advances and the quality of increasing osteosynthesis material, more and more locked plates have been implanted over the last 20 years. The aim of this study was to determine whether the complication rate during plate removal differs between conventional and locked plates.

MATERIAL AND METHODS

In this retrospective cohort study, 620 patients were included and divided into two groups based on the type of plate (locked and conventional). Technical complications during implant removal included screw breakage, destroyed screw head, implant breakage, remaining implant material, refracture, bony or soft tissue overgrowth. The following plate-associated complications were identified: osteosynthesis plate not detachable, plate bent or broken, necessity of special tools or plate loosened. Three types of screw-related complications were observed: screw not detachable, screw broken or screw dislocated.

RESULTS

Overall, complications related to the plate or screws were documented in 110 of the 620 cases. These complications occurred in 48 of the 382 cases involving conventional osteosynthesis (7.7% of all removals, 12.6% of all conventional removals) and in 62 of the 238 cases involving locked plate osteosynthesis (10.0% of all removals, 26.1% of all locked plate removals). The statistical analysis showed a significantly higher implant-related complication rate with locked plates compared to the conventional plates (p < 0.01).

CONCLUSIONS

Hardware removal can be a complication-afflicted operation, especially cases involving locked-plate removal should only be performed if a strong indication is evident. Possible benefits of the procedure should be considered carefully, taking the cost-benefit ratio into account.

Risk Factors of Refracture and Morbidity During Removal of Titanium Pediatric Proximal Femoral Locking Plates in Children With Cerebral Palsy

BACKGROUND

Pediatric proximal femoral locking plates (PFLPs) are widely used when performing proximal femoral osteotomy in children with cerebral palsy (CP). The purpose of this study is to report the difficulties and risk factors of titanium PFLPs removal in CP.

METHODS

PFLP removal was performed in 58 hips of 33 patients (17 males, 16 females). The mean age at the time of surgery (plate removal) was 10.9 (range, 5.7 to 19.2) years. The patients were divided into 2 groups as group 1 and 2, if any difficulty was observed during surgery or not.

RESULTS

Difficulty was not detected in 42 (72.4%) hips (group 1). Difficulties were encountered in 16 (27.6%) hips (group 2). A total of 364 screws were used (259 in group 1, 105 in group 2). The mean plate screw density ratios were 0.88 in group 1 and 0.94 in group 2. The difference between group 1 and 2 was statistically significant. The mean duration between the insertion and removal of the PFLP was 14.9 months (11.9 mo in group 1, 22.7 mo in group 2). The difference between group 1 and 2 was statistically significant. The screw heads were cut and the shafts were left in the bone in 4 hips (4 screws); 3 of these 4 screws were calcar screws. Therefore, calcar screw application can be accepted as a handicap for screw removal.

CONCLUSIONS

As a conclusion, this study suggested that difficulty in titanium PFLP removal in CP is common and PFLP removal is not a harmless procedure. A longer time from internal fixation to removal, increased plate screw density ratio, and calcar screw application are risk factors for difficulties in titanium PFLP removal in CP.

LEVEL OF EVIDENCE

Level III.

Distal tibial fracture: An ideal indication for external fixation using locking plate

OBJECTIVE

To evaluate the feasibility and efficiency of one-stage external fixation by using locking plate in distal tibial fractures.

METHODS

In this non-control prospective study, 28 patients with distal tibial fractures were included and underwent one-stage external fixation by using locking plate. There were 21 males and 7 females, with a mean age of 43 years (19-63). According to AO/OTA fracture classification, there were 9 cases of Type A1, 9 of Type A2, 10 of Type A3 fractures. There were 21 close and 7 open fractures. The locking plate was placed on the anteromedial aspect of the tibia with 4-5 bicortical screws inserted in both distal met- aphysis and diaphysis. The radiographic and clinic results were evaluated.

RESULTS

All patients were followed up for the average of 16 months (ranging from 12 to 21 months). The average surgery duration was 38 (25-60) minutes. The mean time to fracture healing were 14.6 ± 2.67, 17.5 ± 3.66, and 18.4 ± 3.37 (p < 0.05) weeks in type A1, A2, and A3 fractures respectively. By the end of the follow-ups, the mean AOFAS score were 96.11 ± 2.32, 92.67 ± 1.80 and 92.00 ± 2.06 (p > 0.05) in type A1, A2, and A3 fractures respectively. None of nonunion, deep infection, or breakage of screw or plate were observed.

CONCLUSIONS

Distal tibial fracture was the ideal indication for external fixation using locking plate. The external plating is characterized by ease of performance, less invasive, fewer soft tissue impingement, improved cosmesis, and convenient for removal.

Elective implant removal in symptomatic patients after internal fixation of proximal humerus fractures improves clinical outcome

Background

Operative treatment is the standard for severely displaced proximal humerus fractures, but functional impairment can persist. Retaining of the implant can be a reason and in other fracture situations has proved to ameliorate patient satisfaction. The aim of this study was to analyse the functional outcome after locking plate removal in proximal humerus fractures.

Methods

In a two-year period, all symptomatic patients with plate osteosynthesis for proximal humerus fracture and hardware removal were retrospectively evaluated clinically and radiologically pre- and post-implant removal. Evaluation included Constant score, height of plate position and possible impingement, as well as intraoperative complications.

Results

Twenty patients met the inclusion criteria. The mean age was 56 ± 12 years. The plates were placed 6.9 ± 3 mm distal to the greater tubercle. The operation was performed in 35 ± 10 min and no intraoperative complications were reported. The Constant score improved significantly after implant removal from 71 to 76 (p = 0.008).

Conclusion

Symptomatic patients after locked plate osteosynthesis for proximal humerus fractures showed statistically significant improvement of the Constant score after implant removal.

External Fixation Using a Locking Plate: A Reliable Way in Treating Distal Tibial Fractures

The surgical treatment of distal tibial fractures is still challenging. The purpose of this study was to evaluate the clinical and radiographic results associated with the use of a precontoured distal femoral locking plate as an external fixator in treating distal tibial fractures. From August 2011 to October 2012, 28 patients with distal tibial fractures were consecutively enrolled in this study. There were 9 OTA 43.A1, 9 43.A2, and 10 43.A3, including 21 closed and 7 open fractures. The precontoured distal femoral locking plate was placed on the anteromedial aspect of the tibia as an external fixator. All patients were followed for an average of 16 months. The mean surgical duration was 38 (25-60) minutes. The mean time until fracture healing was 16.7 (12-24) weeks. At final follow-up, the mean American Orthopaedic Foot and Ankle Society score was 93 (88-100). There were no nonunions, deep infections, or implant fractures. Three patients had transient superficial pin site infection, but these did not change the clinical outcome. External fixation using a precontoured distal femoral locking plate is a reliable option in treating distal tibial fracture. The procedure is easy to perform, is less invasive, and the low profile plate can be concealed under stockings and can be conveniently removed.

One-Stage External Fixation Using a Locking Plate: Experience in 116 Tibial Fractures

The authors report the results of 1-stage external fixation using a locking plate in 116 tibial fractures (85 closed and 31 open). The patients were followed for an average of 22 months. The mean duration of surgery was 42 minutes. The mean fracture healing time was 12 weeks for proximal, 20 weeks for shaft, 14 weeks for distal, and 24 weeks for multisegmental tibial fractures. Nonunion, deep infection, and breakage of screws did not occur. External plate fixation is effective for tibial fractures and especially for metaphyseal fractures. It has the advantages of being easy to perform and less invasive, and the plate is conveniently located for removal.

External fixation using femoral less invasive stabilization system plate in tibial proximal metaphyseal fracture

BACKGROUND

The locking plates are often used for internal fixation of closed tibial fractures. The use of a locking plate as an external fixator is still controversial, particularly for closed fractures. The purpose of this study is to evaluate the results of external fixation using the femoral less invasive stabilization system (LISS) plate in proximal metaphyseal fractures of the tibia.

METHODS

We prospectively evaluated 35 patients (26 males and 9 females) with a mean age of 42 years (range, 21 to 62 years) who presented with fresh tibial proximal metaphyseal fractures. According to the AO Foundation and Orthopaedic Trauma Association (AO/OTA) classification, the fractures were identified as type 41-A2 in 18 cases and type 41-A3 in 17 cases, including 25 closed fractures and 10 open fractures. The femoral LISS plate was used to fix these fractures, which was placed on the anteromedial aspect of the tibia as an external fixator. The mean follow-up period was 18 months (range, 13 to 22 months).

RESULTS

All fractures healed in a mean time of 14 weeks (range, 10 to 20 weeks). There was no case of nonunion, deep infection, and loosening of screws and plates. One month after the appearance of cortical bridging on biplanar radiographs, the locking plate was removed within 3 minutes in the clinic without any difficulty. According to the Hospital for Special Surgery (HSS) knee scoring system and American Orthopaedic Foot & Ankle Society (AOFAS) ankle scoring system, the mean HSS score was 91 (range, 85 to 100) and 98 (range, 93 to 100), and the mean AOFAS score was 94 (range, 90 to 100) and 98 (range, 95 to 100) at 4 weeks postoperatively and final follow-up, respectively.

CONCLUSIONS

For proximal metaphyseal fracture of the tibia, external fixation using the femoral LISS plate is a safe and reliable technique with minimal complications and excellent outcomes. Its advantages include ease of performing the surgery, use of a less invasive technique, and convenience of plate removal after fracture healing.