Srecko Sabalic - Academia.edu (original) (raw)
Papers by Srecko Sabalic
Injury-international Journal of The Care of The Injured, Nov 1, 2015
OBJECTIVES All acetabular fractures are difficult to treat surgically, but there are four types i... more OBJECTIVES All acetabular fractures are difficult to treat surgically, but there are four types involving two columns that are particularly challenging. The choice of surgical approach is crucial. The purpose of the study was to determine and evaluate the factors influencing the choice of surgical approach for two-column acetabular fractures. We hypothesised that more accurate preoperative planning, sophisticated technical capabilities, and evolution of surgeon experience will result in more consistent use of non-extensile single surgical approaches. We also evaluated the outcomes of surgical treatment and the correlation with the surgical approach used. DESIGN Retrospective cohort study. PATIENTS AND METHODS A total of 156 patients with 157 acetabular fractures involving two columns (Letournel T-types and both-column) treated surgically in a 25-year period (1988-2013) were included in the study. The acetabular fractures in this study were divided into two groups according to the date of surgery: 81 in Group 1 (1998-2002) and 76 in Group 2 (2003-2013). All fractures were classified preoperatively according to the Judet and Letournel classification system and Matta's categorisation of surgical approach. Four surgical approaches were used: single Kocher-Langenbeck (KL), single ilioinguinal (II), combined Kocher-Langenbeck and ilioinguinal (KL+II), and extended iliofemoral (EIF). The efficacy of the surgical approach utilised was assessed using three parameters: anatomical reduction, surgical time and intraoperative complications. RESULTS There was no statistical difference between Group 1 and Group 2 in the distribution of T-type (p=0.424) and both-column (p=0.425) fractures. In Group 2 more acetabular fractures were treated through single non-extensile approaches compared with Group 1 (90.8% vs. 54.3%, p<0.001). Increase in single approach surgery resulted in shorter mean surgical time (p<0.001) and significant increase in anatomical reduction (p=0.039). The frequency of intraoperative complications was not statistically different (p=0.07) between the two groups, but there was a trend to fewer complications in Group 2. CONCLUSIONS The surgical approaches chosen for acetabular fractures that involve two columns (Letournel T-types and both-column) should become more consistent. The results of this study indicate that the majority of such acetabular fractures can be treated successfully through single surgical approaches.
Medical & Biological Engineering & Computing, Aug 3, 2023
Acta Clinica Croatica, 2020
In recent years, there has been increased interest in the cost of treatment for revision interven... more In recent years, there has been increased interest in the cost of treatment for revision interventions for hip and knee prostheses. In all publications so far, the authors note the high cost of treatment for revision interventions, especially if infection is present. The aim of this study was to compare the cost of treatment and health insurance reimbursements between revision total hip arthroplasty (THA) for infection and revision for aseptic indications (aseptic instability and periprosthetic fracture). Hospital data on 168 patients having undergone revision THA between 2010 and 2018 at the Department of Traumatology, Sestre milosrdnice University Hospital Centre from Zagreb were analyzed. Financial data were collected from the Hospital Information System. Financial analysis included total cost per patient, Croatian Health Insurance Fund reimbursements, cost of implants, and length of hospital stay. The difference between the mean total cost per patient and the mean Croatian Health Insurance Fund reimbursements was-262.83 € (-6.08%) for aseptic instability,-1694.94 € (-17.25%) for infection and-916.49 € (-17.33%) for periprosthetic fracture. The Croatian Health Insurance Fund does not recognize differences in the cost of revision THA for aseptic instability, infection and periprosthetic fracture. Health insurance reimbursement is inadequate for centers that offer revision hip surgery.
Croatian Medical Journal, Jun 1, 2022
Aim To expand our previous findings by increasing the number of patients in a study characterizin... more Aim To expand our previous findings by increasing the number of patients in a study characterizing medicinal signaling cells (MSC) of stromal vascular fraction from lipoaspirate (SVF-LA) and from microfragmented lipoaspirate (SVF-MLA) applied for the treatment of osteoarthritis (OA). Methods Twenty OA patients, including 8 new patients, acquiring autologous microfragmented adipose tissue were enrolled. In-parallel immunophenotyping of SVF-LA and SVF-MLA was performed. The samples were incubated in a DuraClone SC prototype tube targeting the CD31, CD34, CD45, CD73, CD90, CD105, and CD146 surface markers, stained with the DRAQ7 cell nuclear dye and Live/Dead Yellow Fixable Stain, and analyzed by flow cytometry. Results The population phenotypes in SVF-LA and SVF-MLA samples included CD31 + CD34 + CD73 ± CD90 ± CD1 05 ± CD146 ± endothelial progenitors (EP), CD31 + CD34-CD73 ± CD90 ± CD105-CD146 ± mature endothelial cells, CD31-CD34-CD73 ± CD90 + CD105-CD146 + pericytes, CD31-CD34 + CD73 ± CD90 + CD105-CD146 + transitional pericytes, and CD31-CD34 + CD73 high CD90 + CD105-CD146supra-adventitial-adipose stromal cells. Compared with the autologous SVF-LA samples, the prevailing cell type in SVF-MLA were EP, which outnumbered leukocytes and supra-adventitial-adipose stromal cells (SA-ASC). The ratio of progenitor cells in SVF-MLA samples differed between female and male patients, showing a higher EP-pericyte and pericyte-SA-ASC ratio in men. Conclusion Our results, hallmarked by EP-enriched antiinflammatory features and indicating a possible sex-specific impact, contribute to defining the cellular composition of the clinically applied MSC serving as a regenerative cell therapy in OA.
Acta Clinica Croatica, 2016
-Th e aim of the study was to assess the infl uence of gap shape on biomechanical results in extr... more -Th e aim of the study was to assess the infl uence of gap shape on biomechanical results in extra-articular distal humeral fracture: with contact on the posterior part (by anterior gap) and contact on ulnar column (by radial gap). Th e goal was to examine if and to what extent did displacements decrease in comparison with previously examined parallel gap without bony contact. Th e fi nite element analysis on the three diff erent plate constructs was performed, i.e. parallel, perpendicular and newly designed Y shape plate were considered. Displacements were measured on articular surface and gap point. Th e most visible decrease of maximum displacements in the distal part of the model was detected in the Y plate model with axial loading: in case of anterior gap 58.5% and especially at radially formed gap 60.9%. Similarly, at axial loading, displacement at the analyzed point on fracture gap most signifi cantly decreased in Y plate model (by 49.4%) at posterior bony contact. Moreover, the latter showed displacement decrease by 68.5% at ulnar bone contact. Furthermore, if a longer radial plate than the ulnar one was used, varus stress could have been avoided. Study results suggested that suffi cient stability could be ensured with the newly designed Y shape plate.
Injury-international Journal of The Care of The Injured, Sep 1, 2021
Introduction: The aim of this study was to describe a surgical technique and report on patient-ba... more Introduction: The aim of this study was to describe a surgical technique and report on patient-based functional outcomes and complications following open reduction and internal fixation in patients with scapular fractures. Methods: The study comprised 14 patients who were treated with open reduction and internal fixation (ORIF) of a scapular fractures between September 2010 and July 2018. Surgical indications were as follows: medial/lateral displacement greater than 20 mm; shortening greater than 25 mm; angular deformity greater than 40 °; intra-articular step-off greater than 4 mm; and double shoulder suspensory injuries (including fracture of the clavicle, coracoid or acromion with displacement greater than 10 mm). All patients underwent X-ray examination (true AP, Y scapular view) and computed tomography (CT) scans. Fractures were classified according to the revised (AO/OTA) classification system. Functional outcomes were measured using Constant-Murley scores. Results: Seven patients had glenoid fossa fractures, six patients had scapular body fractures and one patient had an acromion process fracture. All glenoid fossa and scapular body fractures were exposed via the Judet approach. Eleven of 14 patients were given Constant-Murley scores at the final follow-up examination; three patients were lost to follow-up. The mean follow-up after injury was 44 months (range, 6-92 months). We found infraspinatus muscle hypotrophy in four patients. The mean Constant-Murley score was 93.45 (±8.93) for the injured arm and 98.36 (±2.91) for the uninjured arm. The mean score between the injured and uninjured arm was 4.91(±6.49), which is an excellent functional outcome according to the Constant-Murley score. Conclusions: Open reduction and internal fixation of displaced scapular fractures is a safe and effective treatment option that results in a reliable union rate and good-to-excellent functional outcome.
Injury-international Journal of The Care of The Injured, Sep 1, 2021
Introduction: The aim of this study was to evaluate the clinical and radiological results of adul... more Introduction: The aim of this study was to evaluate the clinical and radiological results of adult forearm fractures treated with interlocking intramedullary nailing. Methods: This retrospective study included 21 patients who were treated with intramedullary interlocking nailing for forearm fractures between January 2010 and September 2017. All patients were treated with intramedullary forearm nails designed to allow interfragmentary compression. The medical records and radiographs of all patients were evaluated. Fractures were classified according to the AO/OTA classification system by analyzing the radiographs. Union time, union rate, clinical outcome, and complications were evaluated. Results: Primary intramedullary osteosynthesis was performed in 17 patients with forearm shaft fractures. The average union time was 10 weeks (range, 8-16 weeks) in the primary osteosynthesis cohort. Secondary intramedullary osteosynthesis was performed in four patients following the removal of plates and screws due to nonunions. For this group of patients, bone union took an average of 17 weeks (range 8-24 weeks). The overall union rate was 95.24% in the 21 forearm fractures which were treated with an intramedullary interlocking nail with a compression screw that allows interfragmentary compression to be obtained. Overall complications included one nonunion, one postoperative rupture of the extensor pollicis longus tendon, and 1 postoperative transitory radial nerve palsy. Conclusions: Intramedullary interlocking nailing with a compression screw is an alternative method of fixation for treating adult forearm fractures and provides good clinical outcomes with reliable union rates.
![Research paper thumbnail of [Comparison of open and laparoscopic cholecystectomy in the treatment of acute cholecystitis]](https://attachments.academia-assets.com/108272090/thumbnails/1.jpg)
](PubMed, Jan 5, 2005
The paper analyses and compares the results of the treatment of acute cholecystitis with open and... more The paper analyses and compares the results of the treatment of acute cholecystitis with open and laparoscopic approach in a seven-year period. From 1994 to 2000, 311 patients with clinical picture of acute cholecystitis were operated. Open cholecystectomy was done in 162 (52.09%) patients, and laparoscopy in 149 (47.91%). In both patient groups the time from the onset of clinical symptoms to the surgery, and preoperative workup and preparation, were the same. In patients with open surgery the procedure lasted 93 (+/-SD) minutes, and in those with laparoscopic surgery 114 (+/-SD) minutes. Those operated with open method received 5.83 (+/-SD) ampules and 3.75 (+/-SD) tablets of analgesics, and those with laparoscopic surgery 3.2 (+/-SD) ampules and 2.1 (+/-SD) tablets per patient. Antibiotics were administered to 149 patients with open surgery for 4.9 (+/-SD) days and to 68 of those with laparoscopic surgery for 2.29 (+/-SD) days. Patients with open surgery stayed in the hospital 9.55 (+/-SD) days and were on sick leave 43 (+/-SD) days, and those with laparoscopy spent 4.35 (+/-SD) days in hospital and were 16 (+/-SD) days on sick leave. In conclusion, better clinical results and faster return to everyday activities point to the significant advantage of laparoscopic cholecystectomy. Analysis of the results shows that total costs of treatment of working patients are significantly lower than of those with laparoscopic surgery, due to shorter hospital stay, shorter sick leave, and faster recovery.
Journal of Orthopaedic Surgery and Research, Jan 11, 2022
Background: Good clinical outcomes for locking plates as an external fixator to treat tibial frac... more Background: Good clinical outcomes for locking plates as an external fixator to treat tibial fractures have been reported. However, external locking plate fixation is still generally rarely performed. This study aimed to compare the stability of an external locking plate fixator with that of a conventional external fixator for extraarticular proximal tibial fractures using finite element analysis. Methods: Three models were constructed: (1) external locking plate fixation of proximal tibial fracture with lateral proximal tibial locking plate and 5-mm screws (ELP), (2) conventional external fixation of proximal tibial fracture with an 11-mm rod and 5-mm Schanz screws (EF-11), and (3) conventional external fixation of a proximal tibial fracture with a 7-mm rod and 5-mm Schanz screws (EF-7). The stress distribution, displacement at the fracture gap, and stiffness of the three finite element models at 30-, 40-, 50-, and 60-mm plate-rod offsets from the lateral surface of the lateral condyle of the tibia were determined. Results: The conventional external fixator showed higher stiffness than the external locking plate fixator. In all models, the stiffness decreased as the distance of the plate-rod from the bone surface increased. The maximum stiffness was 121.06 N/mm in the EF-11 model with 30-mm tibia-rod offset. In the EF-7 model group, the maximum stiffness was 40.00 N/mm in the model with 30-mm tibia-rod offset. In the ELP model group, the maximum stiffness was 35.79 N/mm in the model with 30-mm tibia-plate offset. Conclusions: Finite element analysis indicated that external locking plate fixation is more flexible than conventional external fixation and can influence secondary bone healing. External locking plate fixation requires the placement of the plate as close as possible to the skin, which allows for a low-profile design because the increased distance from the plate to the bone can be too flexible for bone healing. Further experimental mechanical model tests are necessary to validate these finite element models, and further biological analysis is necessary to evaluate the effect of external locking plate fixation on fracture healing.
Medical & Biological Engineering & Computing
Injury-international Journal of The Care of The Injured, Nov 1, 2015
OBJECTIVES All acetabular fractures are difficult to treat surgically, but there are four types i... more OBJECTIVES All acetabular fractures are difficult to treat surgically, but there are four types involving two columns that are particularly challenging. The choice of surgical approach is crucial. The purpose of the study was to determine and evaluate the factors influencing the choice of surgical approach for two-column acetabular fractures. We hypothesised that more accurate preoperative planning, sophisticated technical capabilities, and evolution of surgeon experience will result in more consistent use of non-extensile single surgical approaches. We also evaluated the outcomes of surgical treatment and the correlation with the surgical approach used. DESIGN Retrospective cohort study. PATIENTS AND METHODS A total of 156 patients with 157 acetabular fractures involving two columns (Letournel T-types and both-column) treated surgically in a 25-year period (1988-2013) were included in the study. The acetabular fractures in this study were divided into two groups according to the date of surgery: 81 in Group 1 (1998-2002) and 76 in Group 2 (2003-2013). All fractures were classified preoperatively according to the Judet and Letournel classification system and Matta's categorisation of surgical approach. Four surgical approaches were used: single Kocher-Langenbeck (KL), single ilioinguinal (II), combined Kocher-Langenbeck and ilioinguinal (KL+II), and extended iliofemoral (EIF). The efficacy of the surgical approach utilised was assessed using three parameters: anatomical reduction, surgical time and intraoperative complications. RESULTS There was no statistical difference between Group 1 and Group 2 in the distribution of T-type (p=0.424) and both-column (p=0.425) fractures. In Group 2 more acetabular fractures were treated through single non-extensile approaches compared with Group 1 (90.8% vs. 54.3%, p<0.001). Increase in single approach surgery resulted in shorter mean surgical time (p<0.001) and significant increase in anatomical reduction (p=0.039). The frequency of intraoperative complications was not statistically different (p=0.07) between the two groups, but there was a trend to fewer complications in Group 2. CONCLUSIONS The surgical approaches chosen for acetabular fractures that involve two columns (Letournel T-types and both-column) should become more consistent. The results of this study indicate that the majority of such acetabular fractures can be treated successfully through single surgical approaches.
Medical & Biological Engineering & Computing, Aug 3, 2023
Acta Clinica Croatica, 2020
In recent years, there has been increased interest in the cost of treatment for revision interven... more In recent years, there has been increased interest in the cost of treatment for revision interventions for hip and knee prostheses. In all publications so far, the authors note the high cost of treatment for revision interventions, especially if infection is present. The aim of this study was to compare the cost of treatment and health insurance reimbursements between revision total hip arthroplasty (THA) for infection and revision for aseptic indications (aseptic instability and periprosthetic fracture). Hospital data on 168 patients having undergone revision THA between 2010 and 2018 at the Department of Traumatology, Sestre milosrdnice University Hospital Centre from Zagreb were analyzed. Financial data were collected from the Hospital Information System. Financial analysis included total cost per patient, Croatian Health Insurance Fund reimbursements, cost of implants, and length of hospital stay. The difference between the mean total cost per patient and the mean Croatian Health Insurance Fund reimbursements was-262.83 € (-6.08%) for aseptic instability,-1694.94 € (-17.25%) for infection and-916.49 € (-17.33%) for periprosthetic fracture. The Croatian Health Insurance Fund does not recognize differences in the cost of revision THA for aseptic instability, infection and periprosthetic fracture. Health insurance reimbursement is inadequate for centers that offer revision hip surgery.
Croatian Medical Journal, Jun 1, 2022
Aim To expand our previous findings by increasing the number of patients in a study characterizin... more Aim To expand our previous findings by increasing the number of patients in a study characterizing medicinal signaling cells (MSC) of stromal vascular fraction from lipoaspirate (SVF-LA) and from microfragmented lipoaspirate (SVF-MLA) applied for the treatment of osteoarthritis (OA). Methods Twenty OA patients, including 8 new patients, acquiring autologous microfragmented adipose tissue were enrolled. In-parallel immunophenotyping of SVF-LA and SVF-MLA was performed. The samples were incubated in a DuraClone SC prototype tube targeting the CD31, CD34, CD45, CD73, CD90, CD105, and CD146 surface markers, stained with the DRAQ7 cell nuclear dye and Live/Dead Yellow Fixable Stain, and analyzed by flow cytometry. Results The population phenotypes in SVF-LA and SVF-MLA samples included CD31 + CD34 + CD73 ± CD90 ± CD1 05 ± CD146 ± endothelial progenitors (EP), CD31 + CD34-CD73 ± CD90 ± CD105-CD146 ± mature endothelial cells, CD31-CD34-CD73 ± CD90 + CD105-CD146 + pericytes, CD31-CD34 + CD73 ± CD90 + CD105-CD146 + transitional pericytes, and CD31-CD34 + CD73 high CD90 + CD105-CD146supra-adventitial-adipose stromal cells. Compared with the autologous SVF-LA samples, the prevailing cell type in SVF-MLA were EP, which outnumbered leukocytes and supra-adventitial-adipose stromal cells (SA-ASC). The ratio of progenitor cells in SVF-MLA samples differed between female and male patients, showing a higher EP-pericyte and pericyte-SA-ASC ratio in men. Conclusion Our results, hallmarked by EP-enriched antiinflammatory features and indicating a possible sex-specific impact, contribute to defining the cellular composition of the clinically applied MSC serving as a regenerative cell therapy in OA.
Acta Clinica Croatica, 2016
-Th e aim of the study was to assess the infl uence of gap shape on biomechanical results in extr... more -Th e aim of the study was to assess the infl uence of gap shape on biomechanical results in extra-articular distal humeral fracture: with contact on the posterior part (by anterior gap) and contact on ulnar column (by radial gap). Th e goal was to examine if and to what extent did displacements decrease in comparison with previously examined parallel gap without bony contact. Th e fi nite element analysis on the three diff erent plate constructs was performed, i.e. parallel, perpendicular and newly designed Y shape plate were considered. Displacements were measured on articular surface and gap point. Th e most visible decrease of maximum displacements in the distal part of the model was detected in the Y plate model with axial loading: in case of anterior gap 58.5% and especially at radially formed gap 60.9%. Similarly, at axial loading, displacement at the analyzed point on fracture gap most signifi cantly decreased in Y plate model (by 49.4%) at posterior bony contact. Moreover, the latter showed displacement decrease by 68.5% at ulnar bone contact. Furthermore, if a longer radial plate than the ulnar one was used, varus stress could have been avoided. Study results suggested that suffi cient stability could be ensured with the newly designed Y shape plate.
Injury-international Journal of The Care of The Injured, Sep 1, 2021
Introduction: The aim of this study was to describe a surgical technique and report on patient-ba... more Introduction: The aim of this study was to describe a surgical technique and report on patient-based functional outcomes and complications following open reduction and internal fixation in patients with scapular fractures. Methods: The study comprised 14 patients who were treated with open reduction and internal fixation (ORIF) of a scapular fractures between September 2010 and July 2018. Surgical indications were as follows: medial/lateral displacement greater than 20 mm; shortening greater than 25 mm; angular deformity greater than 40 °; intra-articular step-off greater than 4 mm; and double shoulder suspensory injuries (including fracture of the clavicle, coracoid or acromion with displacement greater than 10 mm). All patients underwent X-ray examination (true AP, Y scapular view) and computed tomography (CT) scans. Fractures were classified according to the revised (AO/OTA) classification system. Functional outcomes were measured using Constant-Murley scores. Results: Seven patients had glenoid fossa fractures, six patients had scapular body fractures and one patient had an acromion process fracture. All glenoid fossa and scapular body fractures were exposed via the Judet approach. Eleven of 14 patients were given Constant-Murley scores at the final follow-up examination; three patients were lost to follow-up. The mean follow-up after injury was 44 months (range, 6-92 months). We found infraspinatus muscle hypotrophy in four patients. The mean Constant-Murley score was 93.45 (±8.93) for the injured arm and 98.36 (±2.91) for the uninjured arm. The mean score between the injured and uninjured arm was 4.91(±6.49), which is an excellent functional outcome according to the Constant-Murley score. Conclusions: Open reduction and internal fixation of displaced scapular fractures is a safe and effective treatment option that results in a reliable union rate and good-to-excellent functional outcome.
Injury-international Journal of The Care of The Injured, Sep 1, 2021
Introduction: The aim of this study was to evaluate the clinical and radiological results of adul... more Introduction: The aim of this study was to evaluate the clinical and radiological results of adult forearm fractures treated with interlocking intramedullary nailing. Methods: This retrospective study included 21 patients who were treated with intramedullary interlocking nailing for forearm fractures between January 2010 and September 2017. All patients were treated with intramedullary forearm nails designed to allow interfragmentary compression. The medical records and radiographs of all patients were evaluated. Fractures were classified according to the AO/OTA classification system by analyzing the radiographs. Union time, union rate, clinical outcome, and complications were evaluated. Results: Primary intramedullary osteosynthesis was performed in 17 patients with forearm shaft fractures. The average union time was 10 weeks (range, 8-16 weeks) in the primary osteosynthesis cohort. Secondary intramedullary osteosynthesis was performed in four patients following the removal of plates and screws due to nonunions. For this group of patients, bone union took an average of 17 weeks (range 8-24 weeks). The overall union rate was 95.24% in the 21 forearm fractures which were treated with an intramedullary interlocking nail with a compression screw that allows interfragmentary compression to be obtained. Overall complications included one nonunion, one postoperative rupture of the extensor pollicis longus tendon, and 1 postoperative transitory radial nerve palsy. Conclusions: Intramedullary interlocking nailing with a compression screw is an alternative method of fixation for treating adult forearm fractures and provides good clinical outcomes with reliable union rates.
PubMed, Jan 5, 2005
The paper analyses and compares the results of the treatment of acute cholecystitis with open and... more The paper analyses and compares the results of the treatment of acute cholecystitis with open and laparoscopic approach in a seven-year period. From 1994 to 2000, 311 patients with clinical picture of acute cholecystitis were operated. Open cholecystectomy was done in 162 (52.09%) patients, and laparoscopy in 149 (47.91%). In both patient groups the time from the onset of clinical symptoms to the surgery, and preoperative workup and preparation, were the same. In patients with open surgery the procedure lasted 93 (+/-SD) minutes, and in those with laparoscopic surgery 114 (+/-SD) minutes. Those operated with open method received 5.83 (+/-SD) ampules and 3.75 (+/-SD) tablets of analgesics, and those with laparoscopic surgery 3.2 (+/-SD) ampules and 2.1 (+/-SD) tablets per patient. Antibiotics were administered to 149 patients with open surgery for 4.9 (+/-SD) days and to 68 of those with laparoscopic surgery for 2.29 (+/-SD) days. Patients with open surgery stayed in the hospital 9.55 (+/-SD) days and were on sick leave 43 (+/-SD) days, and those with laparoscopy spent 4.35 (+/-SD) days in hospital and were 16 (+/-SD) days on sick leave. In conclusion, better clinical results and faster return to everyday activities point to the significant advantage of laparoscopic cholecystectomy. Analysis of the results shows that total costs of treatment of working patients are significantly lower than of those with laparoscopic surgery, due to shorter hospital stay, shorter sick leave, and faster recovery.
Journal of Orthopaedic Surgery and Research, Jan 11, 2022
Background: Good clinical outcomes for locking plates as an external fixator to treat tibial frac... more Background: Good clinical outcomes for locking plates as an external fixator to treat tibial fractures have been reported. However, external locking plate fixation is still generally rarely performed. This study aimed to compare the stability of an external locking plate fixator with that of a conventional external fixator for extraarticular proximal tibial fractures using finite element analysis. Methods: Three models were constructed: (1) external locking plate fixation of proximal tibial fracture with lateral proximal tibial locking plate and 5-mm screws (ELP), (2) conventional external fixation of proximal tibial fracture with an 11-mm rod and 5-mm Schanz screws (EF-11), and (3) conventional external fixation of a proximal tibial fracture with a 7-mm rod and 5-mm Schanz screws (EF-7). The stress distribution, displacement at the fracture gap, and stiffness of the three finite element models at 30-, 40-, 50-, and 60-mm plate-rod offsets from the lateral surface of the lateral condyle of the tibia were determined. Results: The conventional external fixator showed higher stiffness than the external locking plate fixator. In all models, the stiffness decreased as the distance of the plate-rod from the bone surface increased. The maximum stiffness was 121.06 N/mm in the EF-11 model with 30-mm tibia-rod offset. In the EF-7 model group, the maximum stiffness was 40.00 N/mm in the model with 30-mm tibia-rod offset. In the ELP model group, the maximum stiffness was 35.79 N/mm in the model with 30-mm tibia-plate offset. Conclusions: Finite element analysis indicated that external locking plate fixation is more flexible than conventional external fixation and can influence secondary bone healing. External locking plate fixation requires the placement of the plate as close as possible to the skin, which allows for a low-profile design because the increased distance from the plate to the bone can be too flexible for bone healing. Further experimental mechanical model tests are necessary to validate these finite element models, and further biological analysis is necessary to evaluate the effect of external locking plate fixation on fracture healing.
Medical & Biological Engineering & Computing