Locking Plate Removal Research Articles

Risk of Volar Locking Plate Removal After Distal Radius Fractures: Time-to-Event Analysis

The primary purpose of this study was to describe the rate of volar locking plate (VLP) removal after distal radius fracture and how long it takes for the risk of VLP removal to stabilize. The secondary purpose was to describe the reasons for VLP removal and analyze the relationship between it and the Soong index. This was a single-center retrospective cohort study. Patients aged >18 years with distal radius fracture who underwent VLP fixation were included. Hardware removal, time until VLP removal, and the primary reason for removal were recorded. The implant prominence was measured as described by Soong. We used Kaplan-Meier curves and risk tables to describe the risk of VLP removal and variation over time. Multivariable logistic regression was used to assess the relationship between Soong grade and VLP removal. A total of 313 wrists were included. There were 35 cases of VLP removal, with an overall incidence of 11.2% at 15 years of follow-up. The incidence rate was 1.2 per 100 individuals per year for the entire cohort. The risk of VLP removal decreased from 6.2% in the first postoperative year to 1.7% in the second year and 1.4% in the third year. Beyond that, the rate remained <1% per year throughout the follow-up period. The median hardware removal time was 11 months. The main reasons for VLP removal were tenosynovitis, implant-associated pain, and screw protrusion. We found no association between Soong grade and VLP removal. Volar locking plate removal after distal radius fracture was more common in the first year after surgery and remained notable until the third year. Regular monitoring and patient education to assess possible complications related to hardware are important during this period. Therapeutic IV.

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

PurposeTo 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.MethodsPatients 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.ResultsIn 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%).ConclusionsArthroscopic-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 EvidenceLevel IV, therapeutic case series.

Volar locking plate removal after distal radius fracture: a 10-year retrospective study.

Distal radius fracture (DRF) is the most common upper extremity fracture. After the introduction of volar locking plate (VLP) fixation, treatment has shifted from conservative management to more operative management. The implant removal rate after VLP fixation in patients with DRF varies and the reasons for removal and associated patient characteristics have not been clearly defined. This study aimed to compare the characteristics of patients who underwent VLP with and without subsequent implant removal. Second, the rate of implant removal according to the implant position and type was investigated. Finally, we summarized clinical outcome with implant removal, the reasons for, and complications associated with implant removal. In this retrospective study, patient data were collected between January 1, 2008, and December 31, 2017. The study population was divided into two groups based on subsequent implant removal. Data on patient characteristics, such as age, sex, comorbidities, side of the fractured arm, the AO Foundation and Orthopaedic Trauma Association classification of the DRF, plate position grade based on the Soong classification type, type of inserted plate, insurance coverage, and treatment costs were collected. Furthermore, we investigated the reason for implant removal, clinical outcomes, and post-removal complications. After applying the exclusion criteria, 806 patients with a total of 814 DRFs were included in the study. Among the 806 patients who underwent VLP fixation for DRF, 252 (31.3%) patients underwent implant removal. Among the patients undergoing implant removal, the mean age was 50.8 ± 14.0years, 94 (37.3%) were male. The average time to implant removal from the fracture fixation was 12.1 ± 9.2months (range 1-170months). When comparing groups, patients who underwent implant removal were significantly younger and had fewer cases of diabetes, hypertension, and cancer history. According to the Soong plate position grade, the most common position was G1 in both groups. Although there was no significant difference (p = 0.075), more G2 cases were found in the removal group (15.0%) than in the retention group (10.2%). About 66.5% of the patients with implant removal had other health insurance as well as the national service, compared with 47% of the patients with implant retention. In total, 186 patients (73.8%) underwent implant removal despite being asymptomatic after the bony union. The patient satisfaction scores improved from 4.1 to 4.4 after implant removal, and 93% of the patients answered that they would choose implant removal again. Only 10% of the patients who underwent removal reported minor complications. No major complications were reported. Although the implant removal was conducted without clinical symptoms in the majority of patients, overall patients presented improved functional outcomes with implant removal. The evidence is inconclusive regarding its necessity, however, implant removal after VLP fixation for DRF is not a challenging procedure and is not associated with major complications. Level IV.

Incidence for volar locking plate removal following distal radius fracture surgery

IntroductionDistal radius fracture is the most common fracture in adults. The most common treatment for distal radius fracture is non-operative cast immobilization, although there are injuries that require surgical treatment. During the past decade, studies have reported a large increase in the surgical treatment of distal radius fractures with open reduction and internal fixation using volar locking plates. The aim of this study was to investigate the incidence and trends for plate removal after plate fixation of distal radius fractures.Materials and methodsThe study covered all patients 18 years of age and older who had a surgically treated distal radius fracture with open reduction and internal fixation in Finland between 1998 and 2016. Patient data were obtained from the Finnish National Hospital Discharge Register. The association between increased number of platings and plate removals was examined by calculating the removal rates. The study population comprises all patients on a national level, and therefore we did not use statistical testing to analyze the data.ResultsA total of 18,298 patients had surgically treated distal radius fracture with volar plate in Finland during the 19-year study period from January 1, 1998 to December 31, 2016. The number of plate removal operations over the same time period was 2560. The removal rates decreased from over 20% in 1998 to less than 12% in 2016. The mean time period between plating and plate removal operations was 367 days. Most of the plate removals (n = 2235; 87.3%) were conducted during the first 2 years after plating.ConclusionPlate removals have not increased as rapidly as plating operations. The removal rate has declined markedly during the last decade. Nowadays, approximately 11% of distal radius plates are removed.

Retraction Notice: Volar locking plate removal following distal radius fractures: indications and outcomes for 71 fractures.

Retraction Notice: Volar locking plate removal following distal radius fractures: indications and outcomes for 71 fractures.

Patient-Specific 3-Dimensional Printing Titanium Implant Biomechanical Evaluation for Complex Distal Femoral Open Fracture Reconstruction with Segmental Large Bone Defect: A Nonlinear Finite Element Analysis

This study proposes a novel titanium 3D printing patient-specific implant: a lightweight structure with enough biomechanical strength for a distal femur fracture with segmental large defect using nonlinear finite element (FE) analysis. CT scanning images were processed to identify the size and shape of a large bone defect in the right distal femur of a young patient. A novel titanium implant was designed with a proximal cylinder tube for increasing mechanical stability, proximal/distal shells for increasing bone ingrowth contact areas, and lattice mesh at the outer surface to provide space for morselized cancellous bone grafting. The implant was fixed by transverse screws at the proximal/distal host bone. A pre-contoured locking plate was applied at the lateral site to secure the whole construct. A FE model with nonlinear contact element implant-bone interfaces was constructed to perform simulations for three clinical stages under single leg standing load conditions. The three stages were the initial postoperative period, fracture healing, and post fracture healing and locking plate removal. The results showed that the maximum implant von Mises stress reached 1318 MPa at the sharp angles of the outer mesh structure, exceeding the titanium destruction value (1000 MPa) and requiring round mesh angles to decrease the stress in the initial postoperative period. Bone stress values were found decreasing all the way from the postoperative period to fracture healing and locking plate removal. The overall construct deformation value reached 4.8 mm in the postoperative period, 2.5 mm with fracture healing assisted by the locking plate, and 2.1 mm after locking plate removal. The strain value at the proximal/distal implant-bone interfaces were valuable in inducing bone grafting in the initial postoperative period. The proposed patient-specific 3D printed implant is biomechanically stable for treating distal femoral fractures with large defect. It provides excellent lightweight structure, proximal/distal bone ingrowth contact areas, and implant rounded outer lattice mesh for morselized cancellous bone grafting.

Early locking plate removal following open reduction and internal fixation of proximal humeral fractures could prevent secondary implant-related complications

IntroductionProximal humeral fracture is a common cause of morbidity in the elderly and poses a challenge for the orthopedic surgeon. Open reduction and internal fixation (ORIF) with a locking plate is associated with high rate of secondary implant-related complications (IRC). Early implant removal could potentially reduce the risk of IRC and further improve the outcome in relatively asymptomatic patients. The purpose of this study was to evaluate the clinical and radiologic outcomes following implant removal. MethodsA total of 56 patients with an average age of 63 ± 13 years and a mean follow-up of 29 months were evaluated retrospectively following removal of a locking plate in the proximal humerus. Postoperative functional outcomes were evaluated with the Constant-Score, Subjective shoulder value and Quick-DASH score. ResultsEarly implant removal resulted in high functional outcomes with 96% of the patients reporting an improvement of their shoulder function following implant removal. No intraoperative complications were reported. Avascular necrosis (AVN) of the humeral head occurred in 12.5% of the patients, but no secondary screw cut-out was reported. ConclusionEarly implant removal might be a safe option to avoid secondary IRC with significant subjective functional improvement also in asymptomatic patients. Although early implant removal cannot reverse the process of AVN, it could potentially prevent secondary IRC and subsequent glenohumeral cartilage destruction.

Biomechanical Evaluation of Dual Plate Configurations for Femoral Shaft Fracture Fixation

Aim This study aimed at comparing the mechanical properties of conventional and locking dual plates in adjacent and orthogonal orientations for the surgical fixation of transverse femoral shaft fractures. It also assessed the failure mechanics after dual adjacent and orthogonal locking plate removal. Methods Thirty-two composite femurs were transversally osteotomized and randomly assigned for fixation with either dual locking or compression plates in an adjacent or orthogonal configuration. Sixteen specimens were preloaded axially to 20 N and single-leg stance loads were simulated. The remaining sixteen constructs were subjected to torsional loads of 10 Nm at a rate of 10 Nm/s in external and internal rotation of the femoral head in relation to the knee. Overall combined rotational stiffness was calculated. Eight different specimens with no osteotomy underwent the same experiments after dual locked plate removal and were tested to failure in combined eccentric axial and torsional modes. Data were statistically processed using a two-tailed t-test and one-way analysis of variance for the comparison of means between two or more groups, respectively. Results Orthogonal constructs were statistically stiffer in axial loading compared to their adjacent counterparts in both conventional and locking configurations (p<0.001). Dual locking plates provided higher torsional stiffness than conventional ones within each plate orientation (p<0.01). Neither axial/torsional strength nor failure loads differed between constructs that had adjacent or orthogonal dual locking plates instrumented and then removed (p>0.05). Conclusions In both orthogonal and adjacent orientations, double locking plates provide higher stability than their dual conventional counterparts. Orthogonal dual plate configuration is more stable and biomechanically superior to dual adjacent plating for constructs fixed with either standard compression or locking plates.

Causes for difficulty in removal of locking plate and screws and their handling skills

As locking plate is widely used in periarticular and comminuted fractures as well as in fixation of osteoporotic bone, the events involving difficulty in removal of a locking plate increase gradually. Little research addresses the difficulty in implant removal. Stripping of the recess of the screw head, cross-threading between threads in the screw head and screw hole and cold welding are the main causes for difficulty in removing screws from a locking plate. Skills for implant removal include simple ones that require no use of special devices and complex ones that require use of special devices. Difficult implant removal will result in lengthened operation time, increased risk of secondary invasive surgery, residues of metallic shavings and so on. Prevention is the most effective countermeasure. This review summarizes the cause for difficult removal of locking plate and screws as well as the removing skills to help orthopedic surgeons prevent and respond to the difficulties intraoperatively. Key words: Bone plates; Fractures fixation, internal; Skills; Causes

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

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. 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. 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. 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 III.

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

BackgroundOperative 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.MethodsIn 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.ResultsTwenty 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).ConclusionSymptomatic patients after locked plate osteosynthesis for proximal humerus fractures showed statistically significant improvement of the Constant score after implant removal.

Influencing factors for difficult removal of locking head screws and locking compression plate

Objective To analyze the factors that may lead to difficult removal of locking compression plate (LCP) and locking head screws (LHS). Methods We retrospectively reviewed medical records of the 308 patients with extremity fracture who underwent implant removal at our institution from September 2004 to November 2013. They were 190 males and 118 females, with an average age of 36.8 years (from 12 to 82 years). The mean interval from hardware implantation to removal was 16.3 months (from 2 to 56 months). Their fractures involved humerus, ulna, radius, clavicle, femur, tibia and ankle joint. We extracted the following data: difficulty in removal; duration of implant stay in the body; size, position, insertion technique and cortical purchase of LHS; positional relationship between LHS and LCP (orthogonal or non-orthogonal). After we identified potential factors that might have been associated with difficult removal of LHS and LCP in fractures of upper and lower limb respectively using Mann Whitney U test and Chi-square test, we used multiple logistic regression analysis to determine the independent influencing factors. Results Of the 308 patients we analyzed, difficult removal occurred in 37. Fractures at distal humerus had the highest incidence of difficult removal (41.7%), followed by fractures at proximal forearm (33.3%), proximal femur (33.3%) and femur shaft (33.3%). The incidence in malleolar fractures was low (4.0%). Logistic regression analysis suggested the following independent risk factors: long implant stay in the body, young age, and bicortical purchase of LHS for patients with upper extremity fracture (P < 0.05); long implant stay in the body, LHS of a small diameter and percutaneous insertion of LHS for patients with lower extremity fracture (P < 0.05). Conclusions If implant removal is indicated, surgery should be performed as soon as radiographs show fracture healing. To reduce the incidence of difficult removal of LHS and LCP, surgeons should in their preoperative plan and actual procedures take into account different fracture locations and different factors that may lead to difficulty in removal. Key words: Bone plates; Bone nails; Device removal; Factor analysis, statistical

Use of the locking guide in facilitating the removal of locking plates.

Use of the locking guide in facilitating the removal of locking plates.

Clinical Assessment after the Volar Locking Plate Removal of Distal Radius Fracture

23 Copyright c 2014 The Korean Fracture Society. All rights reserved. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received February 5, 2013 Revised July 6, 2013 Accepted October 12, 2013 Address reprint requests to: Joo-Yong Kim, M.D. Department of Orthopedic Surgery, Inje University Pusan Paik Hospital, 75 Bokji-ro, Busanjin-gu, Busan 614-735, Korea Tel: 82-51-890-6257ᆞFax: 82-51-892-6619 E-mail: honaud0@naver.com

Maqdes A, Levy B, Klouche S, Hardy P: The feasibility and results of an arthroscopic removal of humeral locking plates and glenohumeral arthrolysis after proximal humeral fractures. Knee Surg Sports Traumatol Arthrosc 2013 Feb 9. [Epub ahead of print] Doi 10.1007/s00167-013-2437-8

It is with great interest that we read the paper by Maqdes et al. [3] regarding ‘‘the feasibility and results of an arthroscopic removal of locking plates and glenohumeral arthrolysis after proximal humeral fractures’’, published in Knee Surgery Sports Traumatology Arthroscopy online first in February 2013. Six months after the surgical treatment as described before, the results of eleven patients were evaluated. The authors concluded that the technique is very beneficial, feasible for shoulder surgeons, and that it should become the standard technique for patients with indication for the implant removal of locking plates after proximal humeral fractures [3]. Our study group published the technique of ‘‘Arthroscopic locking plate removal after proximal humeral fractures’’ in April 2009 already [4]. In November 2009, Dines et al. [1] published ‘‘Arthroscopic removal of proximal humeral locking plates’’ in the journal Knee Surgery Sports Traumatology Arthroscopy. We agree with the findings of Dines et al. and Maqdes et al. [1, 3] regarding the technique and the feasibility of arthroscopic locking plate removal of proximal humeral fractures. Several surgeons have benefitted from 4 years experience in applying this technique to more than fifty patients and share the opinion that an arthroscopy is mandatory in the context of hardware removal after locked plating of proximal humeral fractures [2]. In their paper, Maqdes et al. [3] state that to their ‘‘...knowledge, there are no studies in the literature that have reviewed the results of combined arthroscopic proximal humeral plate removal and glenohumeral arthrolysis’’ and that ‘‘...although none of these authors statistically evaluated their results, they all agree on the benefits of arthroscopically assisted or all-arthroscopic removal of material’’. In May 2011, our study group published prospective results online, comparing the results of twenty patients with arthroscopic implant removal to those of nine patients with open hardware removal with a median 9.5 months after locked plating of proximal humeral fractures [2]. Despite being written in German, an English abstract is listed in ‘‘PubMed’’. Using the searching terms ‘‘arthroscopic implant removal’’, ‘‘implant removal proximal humerus’’, ‘‘arthroscopy proximal humerus’’ or ‘‘arthroscopy proximal humeral fracture’’, the paper can easily be found, as can the publications concerning the technique of arthroscopic implant removal that were cited by Maqdes et al. [3]. Had the corresponding author been contacted, information regarding the results would have been provided with pleasure. We understand the paper might have simply been missed in a literature search, for example due to an English language filter, we would hence like to take the opportunity to briefly outline our findings in addition to the information provided in the English abstract of the paper [2]. The ageand gender-related Constant Score of the arthroscopically treated group was 76.3 ± 21.9 % compared to 79.5 ± 17.5 % in the openly treated group; no significant difference was found between the two groups (n.s.). All arthroscopically treated patients (n = 20) had a subacromial arthrolysis, in thirteen patients (65 %) the limited range of motion made an intraarticular arthrolysis with partial or complete 360 -capsulotomy necessary. In 85 % (n = 17), concomitant intraarticular pathologies of This comment refers to the article available at doi:10.1007/s00167013-2437-8.

Difficulties encountered removing locked plates.

Locked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant. A retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure. Implant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ. The majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intraoperatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all available extra equipment (mainly metal cutting burrs and screw removal sets) should be available in theatre.

Difficulties encountered removing locked plates

INTRODUCTIONLocked plates are commonly used to obtain fixation in periarticular and comminuted fractures. Their use has also gained popularity in repairing fractures in osteoporotic bone. These plates provide stable fixation and promote biological healing. Over the last 3 years, we have used over 150 locked plates with varying success to fix periarticular fractures involving mainly the knee and ankle. In this study, we report our clinical experience and the difficulties encountered when removing locked plates in adult patients with a variety of indications including implant failure, infection, non-union and a palpable symptomatic implant.METHODSA retrospective analysis was performed of patients enrolled prospectively into a database. Included in the study were 36 consecutive adult patients who each underwent the procedure of locked plate removal in a single inner city level 1 trauma centre. Data collected included primary indication for fixation, indication for implant removal, time of the implant in situ, grade of operating surgeon and difficulties encountered during the procedure.RESULTSImplant removal was associated with a complication rate of 47%. The major problems encountered were difficulty in removing the locked screws and the implant itself. A total of ten cold welded screws were found in eight cases. Removal was facilitated by high speed metal cutting burrs and screw removal sets in all but one case, where a decision was made to leave the plate in situ.CONCLUSIONSThe majority of studies investigating implant removal and problems encountered in doing so report a relatively high complication rate. With the advent of locking plates and their growing popularity, difficulties are now being seen intra-operatively when removing them. There is a paucity of data, however, specifically directed at locking plate removal. We recommend that surgeons should be aware of the potential complications while removing locked plates. Fluoroscopic control and all available extra equipment (mainly metal cutting burrs and screw removal sets) should be available in theatre.

Removal of Locking Plates: New Implant, New Challenges and New Solutions

Removal of locking plates in many ways poses novel challenges compared to conventional plates. None of the techniques described for the removal of locking plates are adequate for all situations. We report our experience of 27 patients from whom a total of 33 locking plates were removed. We also describe a novel technique for the removal of locking plates which in our experience could be used in most of these patients because it is appropriate for all situations and, from a technical point of view, is easy to use. Our new technique consists of removing the problematic locking screw by cutting the plate on both sides of the screw hole and using the screw head-plate hole unit for removal. We analyzed all these patients for the location of the plate, number of locking screws, time of implant removal since the initial surgery, reason for removal of the plate, nature of the difficulties encountered during surgery, and any perioperative complications. A total of 43 (17.34%) screws were difficult to remove. Twenty screws were found to be stripped, 15 were jammed and 8 were broken. Fourteen of the 20 stripped screws and all 15 jammed screws were removed using our technique. We found this technique of locking plate removal to be very versatile and useful in most of the cases in which removal was difficult. At the same time, it also causes less damage to the bone compared to other techniques.

Arthroscopic locking plate removal after proximal humeral fractures

The incidence of proximal humeral fractures increases. The locking plate osteosynthesis is a standard procedure to treat displaced proximal humeral fractures. In the mostly affected elderly patients with an osteoporotic bone structure, complication rate is still high. An implant removal is commonly required. But also younger patients often request for hardware removal. The open implant removal with a subacromial and subdeltoideal arthrolysis is an extensive secondary surgery for the patients. We present a new technique to remove a locking plate from the proximal humerus arthroscopically with all advantages of the minimally invasive surgery, and the possibility to treat concomitant intraarticular pathologies parallelly.

Two in vivo surgical approaches for lumbar corpectomy using allograft and a metallic implant: a controlled clinical and biomechanical study

Both bone graft and metallic implants have been used in combination with the necessary anterior rod or plate instrumentation to fill the voids left by vertebral body removal, with the ultimate goal of restoring stability. One type of device that has recently been introduced is an expandable titanium telescoping cage that is designed to be used as a strut implant to fill corpectomy defects. The use of these devices has met varying success. Acceptance by surgeons and spine biomechanicians has been limited by clinical failure with subsequent loss of reduction and increase in kyphosis. In order to further improve patient care, it is critical to evaluate the use of these implants through biomechanical as well as other modes of testing. To compare and contrast the spinal fusion outcome of using allograft bone versus the expandable vertebral body replacement titanium implant in a lumbar corpectomy procedure. Controlled biomechanical study of lumbar spine fusion using bone graft and the expandable cage in an in vivo bovine model after a 4-month postoperative healing period (n=6). ANIMAL MODEL: Twelve Holstein calves aged 4-6 months with L3 and adjacent discs removed to create a simulated lumbar corpectomy defect. Lumbar spine stability after corpectomy repair was quantified by biomechanical parameters. Strength of fusion was assessed by stiffness of ex vivo spine specimens in flexion-extension, lateral bending, and torsion obtained from biomechanical testing. Uniaxial strain at various positions on the surface of the anterior plate was measured during loading as an additional stability parameter. Loading tests were repeated after removal of the anterior instrumentation (plate and the screws). The calves were randomly allocated to groups for corpectomy defect repair with 1) Allograft metatarsal bone and thoracolumbar spine locking plate, n=6; or 2) Expandable vertebral body replacement device, and thoracolumbar spine locking plate, n=6. After a 4-month postoperative period, anterior-posterior and lateral radiographs were taken of the spine, followed by animal sacrifice and harvesting of the lumbar spine for biomechanical and histological testing. For biomechanical testing, uniaxial strain gauges were applied to the thoracolumbar spine locking plate to measure plate deformation during loading in a custom built fixture for application of flexion-extension, lateral bending, and torsion moments in an Instron materials testing machine. These loading tests were repeated with the thoracolumbar spine locking plate removed, thereby loading solely the fused segment. At 4 months postoperative, the stiffness of the calf spines repaired by the metatarsal allograft and thoracolumbar spine locking plate was significantly greater than that of the spines repaired by the expandable cage and thoracolumbar spine locking plate. This finding was true for all three directions of loading (flexion-extension, left-right lateral bending, and torsion). Concordantly, the neutral zone, elastic zone, and range of motion of the spines repaired with the allograft bone were less than that of the spines repaired with the expandable cage. Greater strain values were observed from the gauges on the thoracolumbar spine locking plate of the spines using the expandable cage than the spines using allograft bone. This finding held for all gauge positions (anterior edge, anterior face, posterior edge, and posterior face at the longitudinal midpoint of the plate). After thoracolumbar spine locking plate removal and a repeat of the loading tests, a decrease in stiffness of the construct and a rise in the motion parameters were observed for both the allograft and cage groups. The use of allograft bone for corpectomy defect repair in the lumbar spine appears to contribute to a stiffer and perhaps more stable spine segment compared with using the expandable cage device for such a repair after a 4-month healing period in this in vivo calf model. These findings thus far are based upon the biomechanical data gathered.