Biomechanical comparison of three different surgical methods in the surgical treatment of distal tibial metaphyseal fractures. An animal model study.

BACKGROUND: The aim of this study is to investigate mechanical properties of minimally invasive plate osteosynthesis (MIPO), supracutaneousplating (SP), and unilateral external fixators (UEF) which can be performed for open tibial fractures. METHODS: An unstable diaphysial tibia fracture was created in 60 fresh sheep tibia specimens by performing an osteotomy at the middle of bones. Specimens were divided into 3 groups. Specimens underwent fracture fixation with a standard MIPO technique, im-planting the plate 15 mm from the bone for SP group. Unilateral uniplanar external fixators were achieved for UEF group. First, thirty specimens (10 specimen for each group) were loaded vertically along the tibial axis to 1800 N. Second, other 30 preperated bones were used for cyclical loading to avoid metal fatigue. For dynamic tests, a 350 N force was applied for 10,000 cycles. RESULTS: In compression testing (vertical loading up to 1800 N) of the three fixation instruments; construct stiffness was highest in MIPO group when compared with SP and UEF groups. While the stiffness of the MIPO group was similar to SP group, it was statistically higher than UEF group (P=0.08 and P=0.002, respectively). SP group was significantly stiffer than UEF group (P=0.0021). The mean peak load was highest in SP group and lowest in UEF group. The peak load in SP group was similar to the MIPO group, it was statistically higher than the UEF group (P=0.743 and P=0.002, respectively). CONCLUSION: Based on the biomechanical properties from this in vitro animal model study, SP technique was biomechanically stronger than UEF and has similar biomechanical properties with MIPO in terms of axial loading.

A new modified pararectus approach and visualization: an anatomical study.

INTRODUCTION: The aim of our study was to visualize all the windows used in the pararectus approach with detailed cadaver images to facilitate better understanding of orthopedic surgeons and, in addition, was to modify the incision used in the pararectus approach to a more cosmetic bikini incision. MATERIALS AND METHODS: In total, 20 cadavers fixed in 10% formalin were used in this study. Of these cadavers, 14 were male and six were female, with a mean age at death of 57 (42-82 years). The four windows were defined as follows in all the cadavers: pubic, quadrilateral, sacroiliac, and iliac windows. RESULTS: The most important structure at risk in the pubic window was the corona mortis, as it was observed in 12 (60%) cadavers. In men, the spermatic cord was an important structure at risk in the pubic window. The obturator vessels and nerves were the structures at most risk in the quadrilateral window due to their close location with the quadrilateral surface. The obturator nerve on the medial side and at the entrance of the pelvis through the linea terminalis and lumbosacral truncus were the structures at most risk close to the sacroiliac joint in the sacroiliac window. CONCLUSION: This anatomical study includes highly instructive visual shapes and cadaver images for the acetabulum and pelvis, whose anatomical structures are quite complex. We have found that this modified pararectus approach provides excellent access to the internal pelvic rim. CLINICAL RELEVANCE: The anatomical data regarding the modified pararectus approach in this study will assist orthopedic surgeons in the surgical management of acetabular and pelvic fractures.

Effects of proximal fibular partial excision on medial compartment knee osteoarthritis.

BACKGROUND: This study aimed to investigate the clinical and radiological progression of the patients who underwent proximal fibular partial excision (PFPE) for medial compartment knee osteoarthritis. METHODS: Patients with medial compartment knee osteoarthritis who did not benefit from conservative treatment and accepted the PFPE surgery were involved in this study. Patients with traumatic arthritis, inflammatory arthritis, previous lower extremity fractures, valgus malalignment of the knee, and infection at the planned surgical site, however, were kept apart. Patients were assessed both clinically by Visual Analog Scale (VAS) and American Knee Society Score (AKSS), radiologically by Kellgren Lawrence classification, tibiofemoral angle, and joint-line convergence angle (JLCA). The patients were systematically assessed especially in the sixth month and first, second, and third years of the post-operative period. RESULTS: A total of 35 patients (mean age: 56.5, min: 45, max: 79) were involved in this study. The mean follow-up period was 22.4 months (min: 6, max: 36). It has been observed that: Statistically significant decrease in VAS and increase in AKSS after PFPE (p < 0.001) No statistically significant improvement in preoperative and postoperative tibiofemoral angle and JLCA measurements CONCLUSIONS: The PFPE is a safe and effective surgical treatment for pain relief and functional improvement in medial compartment knee osteoarthritis. More studies are needed on its mechanism of action, long-term effects, and comparison with other treatment options.

EFFECT OF TRANEXAMIC ACID ON FRACTURE HEALING IN RATS.

Introduction: In this study we investigated the effect of tranexamic acid (TXA) on fracture healing in an established animal model, when used to stop bleeding in orthopedic trauma surgery. Materials and Methods: This study was a randomized, controlled, laboratory study. Eighteen Sprague-Dawley rats were randomly assigned to three groups, either receiving TXA intravenously (Group 1), TXA topically (Group 2), or isotonic TXA intravenously and TXA topically in the same amounts for the control group (Group 3). First, a Kirschner wire was inserted retrogradely into the femoral intramedullary canal. Then the femurs were fractured at the midshaft region with blunt guillotine. After 4 weeks, the rats were sacrified and the femurs harvested. Cortical bone volume, callus volume, and bone mineral density were calculated using computer tomography scans. Torsion tests were performed. Groups were compared by maximum torque to failure and callus stiffness. Results: There were no statistical differences in torque to failure and stiffness between the 3 groups. There were no differences in mean total bone volume, callus volume, percent bone volume, or callus density between the groups. Conclusions: A single dose of topical or intravenous TXA has no negative effect on fracture healing when used in traumatic femur fracture surgery in an animal model. Evidence level II; Randomized controlled experimental study.

Introdução: Neste estudo, investigamos o efeito do ácido tranexâmico (TXA) sobre a consolidação de fraturas em um modelo animal estabelecido, quando é usado para estancar o sangramento em cirurgias de trauma ortopédico. Materiais e Métodos: Trata-se de estudo de laboratório randomizado e controlado. Dezoito ratos Sprague-Dawley foram atribuídos randomicamente em três grupos, que receberam TXA por via intravenosa (Grupo 1), TXA tópico (Grupo 2) ou isotônico por via intravenosa e tópico na mesma quantidade como grupo controle (Grupo 3). Primeiro, foi inserido um fio de Kirschner por via retrógrada no canal intramedular femoral. Em seguida, o fêmur dos animais foi fraturado na região média do corpo do fêmur com guilhotina romba. Depois de quatro semanas, os ratos foram sacrificados e os fêmures foram retirados. O volume do osso cortical, o volume do calo e a densidade mineral óssea foram calculados por meio de tomografia computadorizada e foram realizados testes de torção. Os grupos foram comparados de acordo com o torque máximo até a falha e a rigidez do calo. Resultados: Não houve diferença estatística no torque até a falha e rigidez entre os três grupos nem diferenças entre os grupos quanto ao volume médio total do osso, volume e densidade do calo e percentual de volume ósseo. Conclusões: Uma dose única de TXA tópico ou intravenoso não tem efeito negativo sobre a consolidação da fratura quando usada em cirurgia de fratura traumática de fêmur em modelo animal. Nível de evidência II; Estudo experimental controlado randomizado.

Comparison of extension block pinning technique versus pin orthosis-extension block pinning technique for acute mallet fractures: a prospective randomized clinical trial.

INTRODUCTION: The extension block pinning technique (EBPT) is a popular surgical treatment for mallet fractures; however, it has several drawbacks. The purpose of this randomized clinical trial was to compare EBPT to the pin orthosis-extension block pinning method (PO-EBPT) in the treatment of mallet fractures involving more than one-third of the joint surface but without primary joint dislocation. MATERIALS AND METHODS: Sixty-five patients with mallet fractures were randomized into two groups between June 2017 and January 2020: Group I (33 patients) was treated with EBPT and group II (32 patients) was treated with PO-EBPT. Five patients were lost to follow up due to lack of follow-up and death. There were no significant differences in the clinical and demographic characteristics of both groups. Patients were evaluated according to fracture union, extension lag, distal interphalangeal (DIP) joint range of motion, Crawford's criteria, and complication rates. The patients were followed-up post-operatively at 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and annually thereafter. RESULTS: A total of 60 patients were randomized into two groups: one (30 patients) was treated with EBPT and the second (30 patients) with PO-EBPT. There were no significant differences between the two groups in terms of fracture union and active DIP joint flexion (P = 0.743 and P = 0.059, respectively). The mean extension lag of the DIP joint in the EBPT group was significantly greater than the PO-EBPT group (10° ± 9.47° vs. 4.17° ± 7.2°, P = 0.009). According to the Crawford criteria, the PO-EBPT group showed significantly better outcomes (P = 0.005). The complication rates were similar between groups (P = 0.45). CONCLUSION: In comparison to the EBPT technique, the group of patients operated with PO-EBPT had superior clinical outcomes and less loss of extension at the DIP joint according to the Crawford's criteria.

An oblique osteotomy is better for subtrochanteric shortening in total hip arthroplasty for high hip dislocation: a mechanical comparison of four techniques.

BACKGROUND: Subtrochanteric femoral shortening is used during total hip arthroplasty for high hip dislocation in developmental dysplasia of hip patients. METHODS: We mechanically tested the stability of various commonly used subtrochanteric osteotomy techniques. As the equivalent of a femoral stem placed in a shortened femur without any stable fixation at the osteotomy line, 2 polyvinylchloride pipes were loosely intertwined. 4 different osteotomies (Z-subtrochanteric osteotomy, oblique-45° osteotomy, double Chevron-90° and 120° subtrochanteric osteotomy) were simulated. Torsional and axial loads were applied, and torsional stiffness was calculated for each test model. RESULTS: Z, double Chevron-90° and 120° subtrochanteric osteotomy models demonstrated lower mean torsional stiffness than oblique-45° osteotomy. With the highest torsional stiffness oblique-45° provides the best stability for treatment of high dislocation hips when a subtrochanteric osteotomy is added. CONCLUSIONS: This matches our previous clinical experience. Oblique osteotomy may also provide higher contact surfaces in the osteotomy lines to promote bone healing.

Evaluation of bilateral acromiohumeral distance on magnetic resonance imaging and radiography in patients with unilateral rotator cuff tears.

INTRODUCTION: The aim of this study was to evaluate the difference in the acromiohumeral distance (AHD) between the shoulders with full-thickness rotator cuff tear and contralateral healthy shoulders of the same patients on magnetic resonance imaging (MRI) and radiograph. MATERIALS AND METHODS: We included 49 patients with unilateral full-thickness rotator cuff tears. The mean age of the patients (29 women and 20 men) was 54.57 ± 7.10 years. The shoulders were divided into those with a full-thickness rotator cuff tear and healthy shoulders. The mean AHDs on radiograph and MRI were calculated by two radiologists experienced in the musculoskeletal system. Shoulders with rotator cuff tears on coronal plane and sagittal MRI were divided into 3 (Patte I, II, III) and 4 subgroups (S: superior, AS: anterosuperior, PS: posterosuperior, APS: anteroposterosuperior), respectively. The relationship between the groups and the subgroups was statistically investigated. RESULTS: The mean AHDs on radiograph were 6.93 and 9.11 mm and on MRI were 5.94 and 7.46 mm in the patient and control groups, respectively. The mean AHDs were 6.47, 6.03, and 4.95 mm in Patte I, II, and III, respectively. The difference between the subgroups was statistically significant. According to the sagittal plane topography, the mean AHDs (mm) were 6.39, 6.44, 5.8, and 4.6 mm in the superiorly, anterosuperiorly, posterosuperiorly, and anteroposterosuperiorly localized lesions, respectively. The relationship between S and AS was not statistically significant, and those between S and PS, AS and PS, S and APS, and PS and APS were significant. CONCLUSIONS: In patients with unilateral full-thickness rotator cuff tear, AHD narrowing was observed on the törnekler side after evaluating the bilateral acromiohumeral distance on MRI and radiograph. AHD was significantly reduced by increasing the degree of supraspinatus tendon retraction in the coronal plane MRI and by the posterosuperior and anteroposterosuperior location of the rotator cuff tear in the sagittal plane MRI.

Effect of tranexamic acid on fracture healing in rats / Efeito do ácido tranexâmico na cura de fratura em ratos

ABSTRACT Introduction In this study we investigated the effect of tranexamic acid (TXA) on fracture healing in an established animal model, when used to stop bleeding in orthopedic trauma surgery. Materials and Methods This study was a randomized, controlled, laboratory study. Eighteen Sprague-Dawley rats were randomly assigned to three groups, either receiving TXA intravenously (Group 1), TXA topically (Group 2), or isotonic TXA intravenously and TXA topically in the same amounts for the control group (Group 3). First, a Kirschner wire was inserted retrogradely into the femoral intramedullary canal. Then the femurs were fractured at the midshaft region with blunt guillotine. After 4 weeks, the rats were sacrified and the femurs harvested. Cortical bone volume, callus volume, and bone mineral density were calculated using computer tomography scans. Torsion tests were performed. Groups were compared by maximum torque to failure and callus stiffness. Results There were no statistical differences in torque to failure and stiffness between the 3 groups. There were no differences in mean total bone volume, callus volume, percent bone volume, or callus density between the groups. Conclusions A single dose of topical or intravenous TXA has no negative effect on fracture healing when used in traumatic femur fracture surgery in an animal model. Evidence level II; Randomized controlled experimental study.

RESUMO Introdução Neste estudo, investigamos o efeito do ácido tranexâmico (TXA) sobre a consolidação de fraturas em um modelo animal estabelecido, quando é usado para estancar o sangramento em cirurgias de trauma ortopédico. Materiais e Métodos Trata-se de estudo de laboratório randomizado e controlado. Dezoito ratos Sprague-Dawley foram atribuídos randomicamente em três grupos, que receberam TXA por via intravenosa (Grupo 1), TXA tópico (Grupo 2) ou isotônico por via intravenosa e tópico na mesma quantidade como grupo controle (Grupo 3). Primeiro, foi inserido um fio de Kirschner por via retrógrada no canal intramedular femoral. Em seguida, o fêmur dos animais foi fraturado na região média do corpo do fêmur com guilhotina romba. Depois de quatro semanas, os ratos foram sacrificados e os fêmures foram retirados. O volume do osso cortical, o volume do calo e a densidade mineral óssea foram calculados por meio de tomografia computadorizada e foram realizados testes de torção. Os grupos foram comparados de acordo com o torque máximo até a falha e a rigidez do calo. Resultados Não houve diferença estatística no torque até a falha e rigidez entre os três grupos nem diferenças entre os grupos quanto ao volume médio total do osso, volume e densidade do calo e percentual de volume ósseo. Conclusões Uma dose única de TXA tópico ou intravenoso não tem efeito negativo sobre a consolidação da fratura quando usada em cirurgia de fratura traumática de fêmur em modelo animal. Nível de evidência II; Estudo experimental controlado randomizado.

Comparison of the efficacy of irrigation with epinephrine or tranexamic acid on visual clarity during arthroscopic rotator cuff repair: A double-blind, randomized-controlled study.

OBJECTIVES: This study aims to investigate whether there was a difference between epinephrine (EPN) and tranexamic acid (TXA) in providing visual clarity during arthroscopic rotator cuff tear repair. PATIENTS AND METHODS: This double-blind, prospective, randomized-controlled clinical study included a total of 90 patients (42 males, 48 females; mean age: 55.6±8.3 years; range, 18 to 69 years) in whom either EPN (EPN group, n=47) or TXA-diluted irrigation solutions (TXA group, n=43) were used during rotator cuff tear arthroscopy between December 2017 and November 2019. Arthroscopy was performed using irrigation fluid containing 0.33 mg of EPN per 1 L of saline in the EPN group and 0.42 mg of TXA per 1 L of saline in the TXA group. All procedures were performed by two specialized shoulder surgeons. Visual clarity (primary endpoint) was rated by the operating surgeon using the Visual Analog Scale (VAS) in the immediate postoperative period. Secondary endpoints included total operating time (TOT), potential thrombotic or thromboembolic side effects, mean arterial pressure (MAP), and total amount of irrigation fluid used. RESULTS: There was no significant difference in the surgeon rated- VAS scores between the groups. The mean VAS score was 7.6±1.62 (range, 4 to 10) in the EPN group and 7.1±1.74 (range, 3 to 10) in the TXA group (p=0.59). No cardiac, thrombotic, or thromboembolic complications were observed in any of the groups. CONCLUSION: Adding TXA to the irrigation fluid during the arthroscopic rotator cuff repair may provide similar visual quality to the EPN, as measured by VAS.

Extension-block pinning to treat bony mallet finger: Is a transfixation pin necessary?

BACKGROUND: Extension-block pinning is a popular treatment for mallet fractures, but it is associated with several pitfalls. Of note, transfixation Kirschner wires used to fix the distal interphalangeal (DIP) joint may cause iatrogenic nail bed injury, bone fragment rotation, chondral damage, or osteoarthritis. The objective of this study was to determine whether a transfixation pin was necessary for extension-block pinning in the treatment of bony mallet fracture. METHODS: Patients were treated with a pin-orthosis extension-block technique if they had been diagnosed with a type IVB mallet fracture according to Doyle's classification. Radiological outcomes were evaluated based on postoperative X-ray results, and functional outcomes were evaluated using Crawford's criteria. RESULTS: Thirteen patients (9 males and 4 females) with a mean age of 26 years were included. The mean time between the injury and surgery was 3.3 days, and the mean follow-up period was 8.2 months (range: 4-12 months). Radiographic bone union was achieved in all patients within an average of 5.1 weeks (range: 5-6 weeks). At the final follow-up, the DIP joint had an average degree of flexion of 76.1° (range: 65°-80°) and an average extension deficit of 3.84° (range: 0°-15°). According to Crawford's criteria, 8 patients had excellent results, 4 patients had good results, and 1 patient had a fair result. No patient reported pain at the final follow-up. CONCLUSION: Satisfactory clinical and radiological outcomes were obtained with the pin-orthosis extension-block technique. Future prospective and randomized studies are justified to confirm the efficacy of this technique.

Treatment of clubfoot with the Ponseti method: should we begin casting in the newborn period or later?

The Ponseti method has become accepted worldwide as the treatment of choice for nonoperative management of clubfoot. However, there has been no research on whether casting should begin in the newborn period (< or = 30 days old) or later (> 30 days but < 1 year old) or on whether the length of the foot at the beginning of casting is predictive of the outcome of therapy. Therefore, we conducted an investigation to compare outcomes in patients started on casting therapy in the newborn period or later. Outcomes were based on Pirani and Diméglio scores. The study population was comprised of 40 clubfeet in 29 consecutive infants with no associated neuromuscular disease, who underwent Ponseti treatment. The median follow-up was 34 months (range, 20-47 months). Casting began in the newborn period on 26 feet of 18 patients (newborn group), and after 1 month of age on 14 feet of 11 patients (older infant group). Final Diméglio scores were significantly worse for the patients whose casts were applied in the newborn period, compared with those who had the first cast applied at a time >30 days postpartum (P = .04). Infants with feet > or =8 cm in length at the start of cast treatment had better final Diméglio scores than those with feet <8 cm. Our findings suggest that casting according to the Ponseti method should begin in infants older than 1 month of age, or with an involved foot > or =8 cm in length.

Factors affecting the fracture healing in treatment of tibial shaft fractures with circular external fixator.

This study aims to analyse the contribution of various risk factors for the delay of tibial shaft fractures treated by circular external fixator and predicting the high risk fractures for delayed union. 32 extraarticular tibial shaft fractures of 31 adult patients treated with circular external fixator were included. The patients were analysed according to age, energy of trauma, having an open fracture or not, AO classification, obliquity, use of supplementary fixation techniques in surgery, distance of fracture line to neighbouring rings, having a pin-track infection or not, reduction score, and smoking. There were eight delayed unions and two non-unions in our study. Consolidation time was significantly shorter (p=0.01) between the supplementary fixation group and the others. There was a significant difference in fracture healing time between pin-track-infected patients and the patients who did not have pin-track infection (p=0.037). In conclusion, our results indicate that non-union infection and not using supplementary fixation techniques are the major factors that delay the healing time. Supplementary fixation enhances the reduction rate and a low reduction score is related with the occurrence of a pin-track infection.

Early results of arthroscopic lateral retinacular release in patellofemoral osteoarthritis.

The aim of this study was to define the postoperative course of middle-aged and elderly patients with patellar chondral lesions after lateral retinacular release and joint debridement. Thirty-five patients in their fifth to seventh decades with Grades 2-4 chondral lesions of the patellofemoral joint, with no patellar instability or severe malalignment, underwent lateral retinacular release and patellofemoral joint debridement by bipolar radiofrequency. Both VAS and WOMAC scores in all three lesion grades were significantly reduced postoperatively. The greatest decrease was observed in the first visit at 3 months, and the pain level continued at about the same level over the next 24 months without significant changes. There were no significant differences between the three lesion grades with respect to changes in VAS scores at each visit. Thermal lateral retinacular release improves the subjective condition of the patient by reducing pain, especially in the postoperative first 3 months.

Risk factors in redisplacement of distal radial fractures in children.

BACKGROUND: The causes of redisplacement following closed treatment of distal metaphyseal radial fractures in children are still controversial. Various risk factors and radiographic indices have been suggested to predict redisplacement. The aims of this study were to prospectively identify the causes of redisplacement and to test the accuracy of previously described radiographic indices and our new method, the "three-point index." METHODS: This prospective study included seventy-five displaced or severely angulated distal radial fractures in seventy-four children under the age of fifteen years. Age, gender, initial complete displacement of the radius, an associated ulnar fracture, the accuracy of the reduction, the maximum degree of obliquity of the fracture line in the sagittal or coronal plane, and the distance to the physis were examined as possible risk factors. Logistic regression analysis was utilized to search for risk factors. We also calculated the cast index, padding index, Canterbury index, gap index, and three-point index on the radiographs of each reduction. The sensitivity, specificity, negative predictive value, and positive predictive value were calculated for each test. RESULTS: Initial complete displacement and the degree of obliquity of the fracture were the most important risk factors for redisplacement. Fractures that were completely displaced initially were 11.7 times more likely to redisplace than were angulated but incompletely displaced fractures. A 20 degree oblique fracture was 4.9 times more likely to redisplace and a 30 degree oblique fracture was 10.9 times more likely to redisplace than was a 0 degree true transverse fracture. The three-point index was superior to the other radiographic indices for predicting redisplacement, with a sensitivity of 94.7%, a specificity of 95.2%, a negative predictive value of 98.4%, and a positive predictive value of 85.7%. The gap index was the next-best measure, but it had a sensitivity of 63.2%, a specificity of 76.2%, a negative predictive value of 87.3%, and a positive predictive value of 44.4%. CONCLUSIONS: Initial complete displacement and the degree of obliquity of the fracture line are the dominant factors affecting redisplacement. Our new radiographic index, the three-point index, should be used to predict redisplacement and assess the quality of the cast treatment of these fractures.

Morphometric effects of acute shortening of the spine: the kinking and the sliding of the cord, response of the spinal nerves.

Spinal shortening is performed for a wide spectrum of diseases. This study was designed to investigate the morphologic effects of shortening on the spinal cord, to enlighten the amount and direction of the sliding of the cord, the alteration of the angles of the roots, and to identify the appropriate laminectomy length. Total vertebrectomy of T12 was applied to ten sheep models after spinal instrumentation. Gradual shortening was applied to five sheep; then, the degree and direction of the sliding of the spinal cord and the angles of the adjacent roots were measured. On five other sheep, additional sagittal sectioning was performed via excision of the pedicles. Measurements were taken at different laminectomy lengths to record kinking of the spinal cord with gradual shortening. The mean sliding of the spinal cord was 9 mm cranially and 7.8 mm caudally. T11 spinal nerves became more vertical caudally, and T12 spinal nerves achieved an ascending position with gradual shortening. Both T11 and T12 spinal nerves were sharply bent in the foramen and on the pedicle of T13, respectively. In full-length shortening, the mean kink of the spine in the sagittal plane was 92.4 degrees for two levels of hemi-laminectomies, 24.6 degrees for complete laminectomy of T11 with hemilaminectomy of T13, and 20.2 degrees for two levels of complete laminectomies. The slippage of the cord is dominant in the earlier stages and kinking is dominant in later stages of shortening. Increasing the laminectomy length by only a half or one level prevents excessive kinking and compressions at the upper and lower margins of the laminectomy. In the later stages of shortening, the spinal nerves near the vertebrectomy site are at risk because of the sharp bending of the nerves. This study describes the mechanism of the sliding and kinking of the cord due to gradual shortening of the spine, which might be useful in spinal surgery procedures. It also states that it is possible to avoid excessive kinking by planning the appropriate technique of laminectomy style in full-length shortening.

Anatomy of the posterior iliac crest as a reference to sacral bar insertion.

There are no detailed anatomic studies focusing on the posterior iliac crest although it frequently is used for posterior stabilization of unstable pelvic fractures. Anatomic dissections were done to evaluate the size of the extraarticular region of the posterior iliac crest and its relationship to the lumbosacral lamina and to show on cadavers the level of sacral bar placement that offers safe and solid fixation. Sixty cadavers were dissected bilaterally. Fifty-one were male and nine were female. The distance between the posterior wall of the sacral canal and the tip of the iliac crest was measured at various levels between the level of the upper border of L5 lamina to the level of the posterosuperior iliac spine. In all the dissections the greatest distances were at the level of the L5-S1 junction, which consequently is the safest level for good bony purchase. The entire length of the posterior iliac crest from the level of the upper border of L5 lamina to the posterosuperior iliac spine was shown to be appropriate for safe and solid bar fixation because all of the distance measurements were greater than 13 mm, which is the smallest safe distance. Below the posterosuperior iliac spine level, insertion of the sacral bars was dangerous because the average measured distance was only 10.38 mm.