Acetabular Revision with McMinn Cup: Development and Application of a Patient-Specific Targeting Device.

BACKGROUND: Surgeries of severe periacetabular bone defects (Paprosky ≥ 2B) are a major challenge in current practice. Although solutions are available for this serious clinical problem, they all have their disadvantages as well as their advantages. An alternative method of reconstructing such extensive defects was the use of a cup with a stem to solve these revision situations. As the instrumentation offered is typically designed for scenarios where a significant bone defect is not present, our unique technique has been developed for implantation in cases where reference points are missing. Our hypothesis was that a targeting device designed based on the CT scan of a patient's pelvis could facilitate the safe insertion of the guiding wire. METHODS: Briefly, our surgical solution consists of a two-step operation. If periacetabular bone loss was found to be more significant during revision surgery, all implants were removed, and two titanium marker screws in the anterior iliac crest were percutaneously inserted. Next, by applying the metal artifact removal (MAR) algorithm, a CT scan of the pelvis was performed. Based on that, the dimensions and positioning of the cup to be inserted were determined, and a patient-specific 3D printed targeting device made of biocompatible material was created to safely insert the guidewire, which is essential to the implantation process. RESULTS: In this study, medical, engineering, and technical tasks related to the design, the surgical technique, and experiences from 17 surgical cases between February 2018 and July 2021 are reported. There were no surgical complications in any cases. The implant had to be removed due to septic reasons (independently from the technique) in a single case, consistent with the septic statistics for this type of surgery. There was not any perforation of the linea terminalis of the pelvis due to the guiding method. The wound healing of patients was uneventful, and the implant was fixed securely. Following rehabilitation, the joints were able to bear weight again. After one to four years of follow-up, the patient satisfaction level was high, and the gait function of the patients improved a lot in all cases. CONCLUSIONS: Our results show that CT-based virtual surgical planning and, based on it, the use of a patient-specific 3D printed aiming device is a reliable method for major hip surgeries with significant bone loss. This technique has also made it possible to perform these operations with minimal X-ray exposure.

Custom-made 3D printing-based cranioplasty using a silicone mould and PMMA.

All types of cranioplasty techniques restore the morphology of the skull and affect patient aesthetics. Safe and easy techniques are required to enhance patients' recovery and the rehabilitation process. We propose a new method of cranioplasty. The 3-dimensional (3D) reconstruction of a thin-layer computed tomography (CT) scan of the skull was used to reflect the intact side onto the defect and subtract the overlapping points from one another. In this way, a 3D model of the planned implant can be built in the required shape and size. The precise fit of the implant can be checked by printing the defective part of the skull in case it can be modified. A sterilisable silicone mould based on the finalized model was created afterwards. Polymethyl methacrylate implants were prepared directly in an aseptic environment in the operating room during surgery. Between 2005 and 2020, we performed 54 cranioplasties on 52 patients whose craniotomies were performed previously for indications of traumatic brain injury, stroke or tumour surgeries. No technical problems were noted during the operations. In 2 cases, septic complications that occurred were not connected to the technique itself, and the implants were removed and later replaced. Our proposed technique based on 3D-printed individual silicone moulds is a reliable, safe, easily reproducible and low-cost method to repair different skull defects.

Comparative Analysis of Bone Ingrowth in 3D-Printed Titanium Lattice Structures with Different Patterns.

In this study, metal 3D printing technology was used to create lattice-shaped test specimens of orthopedic implants to determine the effect of different lattice shapes on bone ingrowth. Six different lattice shapes were used: gyroid, cube, cylinder, tetrahedron, double pyramid, and Voronoi. The lattice-structured implants were produced from Ti6Al4V alloy using direct metal laser sintering 3D printing technology with an EOS M290 printer. The implants were implanted into the femoral condyles of sheep, and the animals were euthanized 8 and 12 weeks after surgery. To determine the degree of bone ingrowth for different lattice-shaped implants, mechanical, histological, and image processing tests on ground samples and optical microscopic images were performed. In the mechanical test, the force required to compress the different lattice-shaped implants and the force required for a solid implant were compared, and significant differences were found in several instances. Statistically evaluating the results of our image processing algorithm, it was found that the digitally segmented areas clearly consisted of ingrown bone tissue; this finding is also supported by the results of classical histological processing. Our main goal was realized, so the bone ingrowth efficiencies of the six lattice shapes were ranked. It was found that the gyroid, double pyramid, and cube-shaped lattice implants had the highest degree of bone tissue growth per unit time. This ranking of the three lattice shapes remained the same at both 8 and 12 weeks after euthanasia. In accordance with the study, as a side project, a new image processing algorithm was developed that proved suitable for determining the degree of bone ingrowth in lattice implants from optical microscopic images. Along with the cube lattice shape, whose high bone ingrowth values have been previously reported in many studies, it was found that the gyroid and double pyramid lattice shapes produced similarly good results.

The roof step cut: A novel technique for bony reconstruction of acetabular roof deficiency during total hip replacement.

OBJECTIVES: This study aims to present a new technique, the roof step cut (RSC), for acetabular augmentation of hip dysplasia. PATIENTS AND METHODS: Between December 2008 and March 2020, we applied the RSC technique in a total of 48 hips of 41 patients (2 males, 39 females; mean age: 50.1±9.5 years; range, 30 to 75 years) with Hartofilakidis type A, B, C hip dysplasia. The RSC technique uses a L-shaped graft cut from the femoral head. The graft is partially inside the acetabulum and partially on the lateral aspect of the ilium. It is fixed with two screws at a 45° angle allowing simultaneous distalization and lateral covering of the cementless cup. Follow-up was done at six weeks, three months, and annually thereafter using standard pelvis anteroposterior X-ray and function scores. The 99mTc bone scintigraphy examination was also performed at around two weeks, six months, and 12 months postoperatively to evaluate the healing process of the graft. RESULTS: The mean follow-up time was 59.6±25.6 (range, 12 to 109) months. No significant center-edge angle changes and no contiguous radiolucent zones at the bone prosthesis interface were observed at the final follow-up. The single-photon emission tomography (SPECT) showed the activity of the bone graft gradually increased after surgery and became almost the same as the reference area after 12 months. Functional evaluation showed a significant improvement after the operation. No complication directly related to the technique was observed. CONCLUSION: In the short-term follow-up, the RSC technique is a reliable procedure for acetabular augmentation of hip dysplasia, providing enough coverage for the cementless cup and assuring proper stability.

Critical analysis of in vitro stability testing of spinal implants and proposal for standardization.

BACKGROUND: The American Society for Testing and Materials (ASTM), considered the gold standard worldwide, requires only testing in physiological saline solution to simulate in vivo conditions in standard testing of spinal implants. RESEARCH DESIGN AND METHODS: We conducted an in vitro study to identify an industrial lubricant with characteristics that are most similar to those of biologically lubricating fat, blood, and tissue fluids. The use of such a material could standardize the results of in vitro mechanical tests for better clinical applications. RESULTS: Our study has shown that the lubricity of physiological saline was well below that of human soft tissues and tissue fluids, and among the motor oils, Castrol GTX3 provided a testing environment similar to that of a living organism. CONCLUSIONS: With the intention of standardizing and preventing a biological hazard, we have developed a reproducible mechanical testing proposal based on our experiments, which, in addition, would allow us to avoid many misunderstandings and contingencies.

The Effect of Pharmacist-Led Intervention on Surgical Antibacterial Prophylaxis (SAP) at an Orthopedic Unit.

Perioperative antibiotic use is a common reason for antibiotic misuse. Evidence suggests that adherence to SAP guidelines may improve outcomes. The purpose of this study was to analyze the impact of pharmacist-led antibiotic stewardship interventions on SAP guideline compliance. The study was conducted at an Orthopedic Department of a tertiary care medical center. SAP compliance and antibiotic exposure in the pre-intervention and intervention period was compared using chi-square, Fisher exact, and Mann-Whitney tests, as appropriate. Prophylactic antibiotic use in orthopedic joint arthroplasties (overall guideline adherence: agent, dose, frequency, duration), clinical outcomes (length of stay-LOS, number of surgical site infections-SSIs), antibiotic exposure and direct antibiotic costs were compared between pre-intervention and intervention periods. Significant improvement in mean SAP duration (by 42.9%, 4.08 ± 2.08 vs. 2.08 ± 1.90 days, p ˂ 0.001), and overall guideline adherence regarding antibiotic use (by 56.2%, from 2% to 58.2%, p ˂ 0.001) were observed. A significant decrease was observed in antibiotic exposure in SAP (by 41%, from 6.07 ± 0.05 to 3.58 ± 4.33 DDD/patient, p ˂ 0.001), average prophylactic antibiotic cost (by 54.8%, 9278.79 ± 6094.29 vs. 3598.16 ± 3354.55 HUF/patient), and mean LOS (by 37.2%, from 11.22 ± 6.96 to 7.62 ± 3.02 days, p < 0.001); and a slight decrease in the number of confirmed SSIs was found between the two periods (by 1.8%, from 3% to 1.2%, p = 0.21). Continuous presence of the clinical pharmacist led to significant improvement in SAP guideline adherence, which was accompanied by decreased antibiotic exposure and cost.

Heme-Induced Oxidation of Cysteine Groups of Myofilament Proteins Leads to Contractile Dysfunction of Permeabilized Human Skeletal Muscle Fibres.

Heme released from red blood cells targets a number of cell components including the cytoskeleton. The purpose of the present study was to determine the impact of free heme (20-300 µM) on human skeletal muscle fibres made available during orthopedic surgery. Isometric force production and oxidative protein modifications were monitored in permeabilized skeletal muscle fibre segments. A single heme exposure (20 µM) to muscle fibres decreased Ca2+-activated maximal (active) force (Fo) by about 50% and evoked an approximately 3-fold increase in Ca2+-independent (passive) force (Fpassive). Oxidation of sulfhydryl (SH) groups was detected in structural proteins (e.g., nebulin, α-actinin, meromyosin 2) and in contractile proteins (e.g., myosin heavy chain and myosin-binding protein C) as well as in titin in the presence of 300 µM heme. This SH oxidation was not reversed by dithiothreitol (50 mM). Sulfenic acid (SOH) formation was also detected in the structural proteins (nebulin, α-actinin, meromyosin). Heme effects on SH oxidation and SOH formation were prevented by hemopexin (Hpx) and α1-microglobulin (A1M). These data suggest that free heme has a significant impact on human skeletal muscle fibres, whereby oxidative alterations in structural and contractile proteins limit contractile function. This may explain and or contribute to the weakness and increase of skeletal muscle stiffness in chronic heart failure, rhabdomyolysis, and other hemolytic diseases. Therefore, therapeutic use of Hpx and A1M supplementation might be effective in preventing heme-induced skeletal muscle alterations.

[Effects of therapeutic suggestions on the recovery of patients undergoing major orthopaedic surgery]. / Az ortopédiai nagymutétek során alkalmazott terápiás szuggesztiók hatása a beteg gyógyulására.

INTRODUCTION AND AIM: Hip and knee replacement surgery is very demanding for patients. Medication consumption is further increased by perioperative anxiety. Besides pain killer and anxiolytic medications, patients' recovery can be enhanced by applying therapeutic suggestions, which are easily applicable during the patient-physician communication. METHOD: In our prospective, randomized, controlled study we examined the effects of positive suggestions on patients undergoing hip or knee arthroplasty in spinal anaesthesia. Members of the suggestion group received the therapeutic suggestions during a pre-surgery physician visit, and by listening to an audio recording during surgery. RESULTS: Compared to the control group (n = 50), in the suggestion group (n = 45) the need of medication (pain killer and adjuvant pain medication) during the surgery was lower (p = 0.037), the mean change from baseline in the well-being of the patients was better on the 2nd [1.31 (0.57; 2.04); p<0.001] and 4th [0.97 (0.23; 1.7); p = 0.011] postoperative day and less transfusion had to be administered (OR: 2.37; p = 0.004). However, there was no difference between the two groups in the postoperative need of medications, in the length of hospitalisation and in the frequency of complications. Conslusion: Our results indicate that the administration of therapeutic suggestions in the perioperative period may be beneficial for orthopaedic surgery patients. Orv Hetil. 2018; 159(48): 2011-2020.

The Use of Adjunct Psychosocial Interventions Can Decrease Postoperative Pain and Improve the Quality of Clinical Care in Orthopedic Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

This study aims to assess the effectiveness of psychosocial techniques to decrease postoperative pain and improve perioperative clinical care in orthopedic surgery. A systematic review and meta-analysis was performed to evaluate the effects of psychosocial methods among adults undergoing orthopedic surgeries. The systematic review included both randomized and nonrandomized trials, but only randomized controlled clinical trials (RCTs) were included in the meta-analysis. Key outcomes were postoperative pain, analgesic requirement, perioperative anxiety, quality of life, and recovery. After searching the databases from January 1980 to September 2016, a total of 62 RCTs were included with a pooled sample size of 4,908. Psychosocial interventions significantly reduced postoperative pain (Hedges' g = 0.31 [95% confidence interval = 0.14, 0.48]), and preoperative and postoperative anxiety (g = 0.26 [0.11, 0.42] and g = 0.4 [0.21, 0.59], respectively). Furthermore, psychosocial interventions improved recovery (g = 0.38 [0.22, 0.54]). However, no significant effects were found for postoperative analgesic use (g = 0.16 [-0.01, 0.32]) and quality of life (g = 0.14 [-0.05, 0.33]). Patient education and relaxation techniques produced the most consistent positive effects, showing benefits on pain, anxiety, and recovery. Cognitive or behavioral techniques improved recovery. Furthermore, larger effects were found for studies that included acute surgeries compared to elective surgeries. The results indicate that psychosocial interventions, especially patient education and relaxation training, may reduce perioperative side effects and improve recovery in patients undergoing orthopedic procedures, but the quality of evidence is generally low. More well-powered, high-quality studies are needed to increase confidence. PERSPECTIVE: In this meta-analysis of RCTs in orthopedic surgeries, significant benefits in postoperative pain, perioperative anxiety, and recovery were found, suggesting that psychosocial interventions, especially patient education and relaxation techniques, are useful in improving clinical care.

The Effectiveness of Psychosocial Interventions as Adjuncts to Orthopaedic Surgery: A Systematic Review Protocol.

AIMS: Pain and anxiety are commonly reported among those undergoing orthopaedic surgery. Improvement in anxiety and pain control might be achieved by supplementing standard care with psychological interventions. However, the effectiveness of adjunctive psychosocial interventions in anxiety and pain control have not been addressed sufficiently by previous systematic reviews in orthopaedic surgeries. The present study aimed to assess the effectiveness of adjunctive psychosocial techniques to improve perioperative clinical care in orthopaedic surgery, to identify the most effective intervention types and to evaluate potential moderators. METHODS: We will perform a systematic review and meta-analysis to address the study aims. PubMed, PsycINFO, CINAHL and ProQuest Dissertations & Theses will be searched between 1980 and 2015. Prospective controlled clinical trials completed in adults, contrasting standard care and standard care supplemented with psychosocial methods, will be eligible for inclusion. Effectiveness will be assessed through the outcomes of postoperative pain intensity, analgesic requirement, perioperative anxiety, quality of life and postoperative recovery. The results of a random-effect meta-analysis will be reported. To aid implementation of best practice, moderating effects of the type and timing of psychosocial intervention, type of surgical intervention and type of anaesthesia will be evaluated through meta-regression. Sensitivity analyses and subgroup contrasts will follow as necessary. DISCUSSION: Recommendations will be made to improve medical care in orthopaedic procedures. The quality of evidence will be rated using GRADE criteria. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of Positive Suggestions on the Need for Red Blood Cell Transfusion in Orthopedic Surgery.

This study examined whether positive suggestions applied without a hypnotic induction in the perioperative period reduces the need for red blood cell transfusions in patients who underwent total hip or knee arthroplasties with spinal anesthesia. No hypnotic assessment was performed. Ninety-five patients were randomly assigned to the suggestion group (n = 45) and to the control group (n = 50). Patients in the suggestion group received verbal suggestions before and audiotaped suggestions during the surgery for reducing blood loss, anxiety, postoperative pain, and fast recovery. Our study showed that using positive suggestions in the perioperative period significantly decreases the necessity for transfusion.

HMGB1 expression and muscle regeneration in idiopathic inflammatory myopathies and degenerative joint diseases.

The High-Mobility Group Box 1 protein (HMGB1) is a known nuclear protein which may be released from the nucleus into the cytoplasm and the extracellular space. It is believed that the mobilized HMGB1 plays role in the autoimmune processes as an alarmin, stimulating the immune response. In addition, muscle regeneration and differentiation may also be altered in the inflammatory surroundings. Biopsy specimens derived from patients with idiopathic inflammatory myopathies (IIM) such as polymyositis or dermatomyositis were compared to muscle samples from patients undergoing surgical interventions for coxarthrosis. The biopsy and surgery specimens were used for Western blot analysis, for immunohistochemical detection of HMGB1 in histological preparations and for cell culturing to examine cell proliferation and differentiation. Our data show lower HMGB1 expression, impaired proliferation and slightly altered fusion capacity in the primary cell cultures started from IIM specimens than in cultures of coxarthrotic muscles. The ratio of regenerating muscle fibres with centralised nuclei (myotubes) is lower in the IIM samples than in the coxarthrotic ones but corticosteroid treatment shifts the ratio towards the coxarthrotic value. Our data suggest that the impaired regeneration capacity should also be considered to be behind the muscle weakness in IIM patients. The role of HMGB1 as a pathogenic signal requires further investigation.

Application of a vibrating device for the prevention of flexion contracture after total knee arthroplasty.

Our research team developed a new, heel support-based static and vibrating complementary treatment method for the prevention of flexion contractures often arising after total knee arthroplasty. We examined the efficiency of the method performing a randomized clinical trial with 144 patients undergoing total knee replacement. Seventy-nine patients were treated for 1 week with a generally used continuous passive motion (CPM) device complemented with our new method, which was based on the application of a static and an alternating heel support. The 65 patients in the control group were treated with only a CPM device as in usual clinical practice. The femoro-tibial angle was measured immediately following surgery, and after 1 week of treatment. At the end of the 1 week treatment, the target extension angle (0° ± 5°) was achieved by significantly more patients with the new combined method. This way the elevated heel rest and the vibrating device proved to be a good adjunct treatment along with the CPM used in routine clinical practice in the first place for the prevention of flexion contractures.

Albumin-coated structural lyophilized bone allografts: a clinical report of 10 cases.

Bone replacement and the use of bone supplementary biological substances have become widespread in clinical practice. Although autografts have excellent properties, their limited availability, difficulties with shaping and donor site morbidity have made allografts a viable and increasingly preferred alternative. The main drawback of allografts is that the preparation destroys osteogenic cells and results in denaturation of osteoinductive proteins. Serum albumin is a well-known constituent of stem cell culture media and we found that lyophilizing albumin onto bone allografts markedly improves stem-cell attachment and bone healing in animal models thus replacing some of the osteoinductive potential. As a first step in the clinical introduction of albumin coated grafts, we aimed to test surgical handling and early incorporation in aseptic revision arthroplasty in humans. We selected patients who needed large structural allografts and the current operation was the last attempt at preserving a moving joint. In a series of 10 cases of hip and knee revision surgery we did not experience any drawbacks of the albumin-coated grafts during handling and implantation. Twelve months radiographic and SPECT-CT follow-up showed that the graft was well received by the host and active remodelling was observed. The lack of graft-related complications and the good 1-year results indicate that controlled trials may be initiated in more common bone grafting indications where long-term effectiveness can be evaluated.

The biological and biomechanical comparison of two bulk bone graft techniques used in case of dysplastic acetabulum.

BACKGROUND: The incorporation of bulk bone grafts in the replacement of dysplastic acetabulum is determined by the biological environment of the recipient site, the size of the contact surface, and the stability of the osteosynthesis used. Based on these, the present study compares the Harris acetabular plasty used routinely by us with the Radojevic L-shaped graft technique. METHODS: For our measurements, we used 20 hemi-pelvises removed from 10 cadavers. In 10 cases, acetabular plasty according to Harris, in 10 cases Radojevic L-plasty, was performed. The biological environment was analyzed; with geometric calculations, the contact surface was determined, and with a material testing apparatus, the primary stability of the osetosynthesis was measured. For the measurements, a new method was developed. RESULTS: The Radojevic technique provides a better biological environment for graft ingrowth. The contact surface is nearly twice as much as in Harris plasty. No significant difference was found in the primary stability of the osteosynthesis used. The deviation on the value of the stability measurements is explained by the differences in the bone quality of the cadavers used. CONCLUSIONS: Based on the 3 aspects examined, the Radojevic L-shaped graft technique has similar stability when compared to the Harris acetabular plasty, but provides better biological circumstances and larger graft host bone contact. Based on this, we started using the L-shaped technique in our department.

Examples of positive suggestions given to patients undergoing orthopaedic surgeries.

In the Department of Orthopaedic Surgery in the University of Debrecen, Debrecen, Hungary, we examined the effectiveness of positive suggestions used in the perioperative period in hip and knee arthroplasties performed under spinal anaesthesia. The goal of the suggestions was to reduce the need for red blood cell transfusion and for analgesics, and to increase the patients' satisfaction. The objective of this article is to present our method with concrete examples of positive suggestions which were given first before the surgery (via personal conversation), then during the operation as well (via audiotaped method). We hope that our article will contribute to the wide-spread awareness of this relatively easy to learn communication method.

Our experience and early results with a complementary implant for the correction of major thoracic curves.

PURPOSE: In our article, we would like to introduce a new auxiliary implant called the CAB hook, for use in posterior approach scoliosis surgery. METHODS: Since 2007, we operated 42 patients with the CAB hook with an average preoperative Cobb angle of 59.3° (28°-92°). In three cases, the posterior approach was preceded by ventral release and Halo traction. In four cases, besides the CAB hooks, SCS hooks and pedicular screws, in three cases both CAB and SCS hooks, in nine cases CAB hooks with SCS pedicular screws, and in 23 cases, only CAB were used. The average follow-up time was 21.6 month (2-51). RESULTS: All the patients are satisfied with the results. No reoperation was needed due to the loss of correction, pain, implant failure, or infection. The average postoperative Cobb angle decreased to 24.7° (4°-60°). Based on this we calculated the Cincinnati Correction Index (CCI), which was 1.53 (0.7-4.8), which means that our correction exceeded the flexibility of the spine based on the lateral bending X-ray by 53 %. CONCLUSION: As with all new surgical techniques and implants after the short learning curve, we were able to improve the degree of correction and decrease the time of surgery. One of the advantages of the CAB hook is that besides a few implant-specific instruments, no special instrumentation is required for insertion, and image intensifier need not be used.

Long-term follow-up of DDH patients who underwent open reduction without a postoperative cast.

We present the results - assessed after bony maturation - of an early anterior approach open reduction performed using our modified technique on 49 hips at 6-24 months of age. We start postoperative functional treatment using a Pavlik harness and an abduction splint, abandoning plaster cast. Secondary surgeries were performed in 11 hips (22.4%) at 3-7 years of age. Our results were 'satisfactory' (Severin Grade I, II) in 96% of the cases. According to the joints' Severin Grade, the total hip replacement probability at an early age is 8.16% in our series. Our principles and practice, introduced in 1980 in terms of secondary surgeries, are in total harmony with the recent literature.

Biomechanical comparison of two stabilization techniques for unstable sacral fractures.

AIM: The purpose of the study was to assess the stability provided by an ilio-iliac dorsal plate fixation technique using an AO narrow DCP on the pelvic brim in vertically and rotationally unstable type-C pelvic ring injuries. MATERIALS AND METHODS: We examined 12 fresh cadaver pelvises in a single limb stance load. A type-C pelvic ring injury (a type I lateral sacral fracture in the classification of Denis with symphysis pubis rupture) was performed on the cadaver specimen and fixed with a four-hole narrow dynamic compression plate to stabilize the symphysis pubis rupture; the sacrum fracture was stabilized either anteriorly with two 3-hole reconstruction plates ("anterior plate osteosynthesis") or with a posterior fixation using a 12-hole narrow DCP. A cyclic load of between 100 and 250 N was applied to the fifth lumbar vertebra of the specimen. An extensometer was attached to both sides of the sacrum fracture to detect movements at the fracture site. RESULTS: We were able to achieve usable measurements in nine specimens. Three measurements were performed on each specimen, and the movements recorded at the fracture gap in trans-sacral plate fixation were higher than or similar to those observed for anterior plate synthesis in 23 out of 27 cases. CONCLUSION: Dorsal ilio-iliac bridge plate fixation provides somewhat reduced stability compared to anterior plate fixation, but the difference is not significant.

Biomechanical examination of the thoracic spine--the axial rotation moment and vertical loading capacity of the transverse process.

Our objective was to examine the load-bearing capacity of the transverse processes of human cadaveric thoracic vertebrae to vertical loads and axial rotation moments (i.e., moment applied in the transverse plane). A secondary objective was to examine the effect of the attached rib stumps. We wanted to demonstrate that the transverse process is durable enough to support the CAB hook--a complementary hook to the CD system--and can handle the vertical load or axial rotation moment during correction of scoliosis. We used 107 thoracic vertebrae removed from 10 cadavers. They were prepared in vertebral pairs, and were fixed into a material testing apparatus. Superoinferior vertical loads and axial rotation moments were applied to the transverse process using the CAB hooks at a rate of 30 mm/min and 8.5°/s respectively until it fractured. We recorded 142 measurements, 99 were for vertical load and 43 for axial rotation moment. The average ultimate vertical load was 338 (SD = 128) N and the average ultimate axial rotation moment was 14.4 (SD = 4.52) Nm. The ultimate axial rotation moment for specimens with rib stumps attached was significantly greater than for specimens without rib stumps 15.9 (SD = 4.1) Nm versus 12.5 (SD = 4.4) Nm. Our results showed that both the vertical and axial rotation loading capability of the transverse process are large enough to withstand significant correctional forces, without fracture, through the CAB hooks.