Posterolateral plate fixation with Pantalarlock® is more stable than nail fixation in tibiotalocalcaneal arthrodesis in a biomechanical cadaver study

BackgroundDespite the promising results of ankle joint arthroplasty, the tibiotalocalcaneal (TTC) arthrodesis remains an established procedure in treatment of combined pathology of the ankle and subtalar joint. Despite the promising results in biomechanical investigations, nonunion rates of up to 24% are described in recent studies. The objective of this work was a comparative study of the biomechanical properties of the posterolateral plate fixation with retrograde intramedullary nail fixation.MethodsTwenty four fresh-frozen human lower leg specimens (12 pairs) were used for the comparative biomechanical testing. Every specimen was preconditioned with 100 N over 200 cycles. After every 250 cycles the force was increased by 50 N from 200 to 600 N. This was followed by cyclic loading in dorsi-/plantiflexion with 800 N for 3000 cycles. All specimens were subjected to bone densitometry (DXA) and computed tomography.ResultsSignificantly higher number of spacimens with nails (4) failed during the cycling testing in dorsi-/plantarflexion and futher two during the cyclic testing with 800 N. Two specimens with plates failed during the cyclic testing with 800 N. Statistical analysis showed that the specimens with the plate were significantly more stable in each test direction. The Pearson correlation demonstrated for the specimens with plate a linear relationship between the stiffness and the determined bone density.ConclusionsThe results demonstrate a significantly superior stiffness of the Pantalarlock®-plate in all testing directions compared with the HAN nail. Probably the position of the plate on the tension side of the joint and the combination of locking and lag screws provide the higher stiffness of the plate system. The correlation of the stiffness with bone density leads to more predictable results of the plate arthrodesis. We hope for a reduction of the pseudarthrosis rate and shorten the postoperative treatment phase. The authors expect advantages in the treatment of high risk patients with severe deformity of the ankle, bone defects, neuropathic deformity, poor bone quality and osteoporosis.     

Prospective continuous study comparing intrafocal cross-pinning HK2® with a locking plate in distal radius fracture fixation

The fixation of distal radius fractures by pinning or locking plates remains controversial. The aim of this prospective continuous study was to compare the results of 28 anterior locking plates with 23 intrafocal cross-pinning HK2^® systems. The mean age of group I (SVP^®, SBI™ plate) was 61 years. There were 15 extra-articular and 13 articular fractures. The mean age of group II (HK2^®, Arex™) was 63 years, with 13 extra-articular and 10 articular fractures. Twelve clinical variables were measured: pain, wrist strength, supination strength, pronation strength, quick DASH score, range of wrist motion in flexion, extension, pronation, and supination, ulnar variance, radial slope, and radial volar tilt. At 40 weeks follow-up, there was no difference between the two groups for 10 variables; two variables showed differences between the two groups: mean quick DASH score was 10.7 for group I, 19.7 for group II, and mean ulnar variance was −0.95 mm for group I, and 1.16 mm for group II. Six transient complications were noted for group I: five tenosynovitis, and one carpal tunnel syndrome. We noted 12 complications in group II: four superficial infections, two secondary displacements, one pin migration, two CRPS type II, two tendon ruptures and one nerve irritation. Generally, plates provided a more stable fixation associated with less complications while the HK2^® system was quicker and less costly. The indications for its use need to be refined with a larger series and longer follow-up.     

Cement-augmented sacroiliac screw fixation with cannulated versus perforated screws – A biomechanical study in an osteoporotic hemipelvis model

IntroductionCement-augmentation is a well-established way to improve the stability of sacroiliac screw fixation in osteoporosis-associated fragility fractures of the posterior pelvic ring. However, to date little is known about the influence of different techniques of cement augmentation on construct stability. The aim of this study was to evaluate the primary stability of cement-augmented sacroiliac screw fixation with cannulated versus perforated screws under cyclic loading.Materials and MethodsA total of eight fresh-frozen human cadaveric hemipelvis specimens with osteoporosis were used. After generating ventral osteotomies on both sides of the sacrum, each specimen was treated using a cement-augmented cannulated screw on one side and a cement-augmented perforated screw on the other side. Afterwards, axial cyclic loading was performed.ResultsNo statistically significant difference was found between cannulated and perforated screws concerning maximum load (356.25 N versus 368.75 N, p = 0.749), plastic deformation (1.95 mm versus 1.43 mm, p = 0.798) and stiffness (27.04 N/mm versus 40.40 N/mm, p = 0.645).ConclusionsConsidering the at least equivalent results for perforated screws, cement augmentation via perforated screws might be an interesting option in clinical practice because of potential advantages, e.g. radiological control before cement application, reduced risk of cement displacement and time saving.     

Single column plate plus other column lag screw fixation vs. both column plate fixation for anterior column with posterior hemitransverse acetabular fractures – a biomechanical analysis using different loading protocols

ObjectivesOpen reduction and internal fixation of both columns is considered the treatment of choice for displaced anterior column with posterior hemitransverse (ACPHT) fractures in non-geriatric patients. Plate fixation of one column combined with lag screw fixation of the other column allows to decrease operative time and approach-related morbidity compared to conventional both column plating. The aim of this biomechanical study was to evaluate whether single column plate plus other column lag screw fixation confers similar stability to both column plate fixation. Physiological loads were simulated using both the single-leg stance (SLS) as well as the sit-to-stand (STS) loading protocols.MethodsA clinically relevant ACPHT fracture model was created using fourth-generation composite hemipelves. Fractures were stabilized with three different fixation constructs: (1) anterior column plate plus posterior column screw fixation (AP+PCS), posterior column plate plus anterior column screw fixation (PP+ACS) and anterior column plate plus posterior column plate fixation (AP+PP).Specimens were loaded from 50 to 750 N with a ramp of 100 N/s. Fracture gap motion (FGM) and relative interfragmentary rotation (RIFR) between the three main fracture fragments were assessed under loads of 750 N using an optical 3D measurement system.ResultsSTS loading generally resulted in higher mean FGM and RIFR than STS loading in the AP+PCS and AP+PP groups, while no significant differences were found in the PP+ACS group. Compared to conventional both column plate fixation (AP+PP), PP+ACS displayed significantly higher FGM and RIFR between the iliac wing and the posterior column during SLS loading. No significant differences in FGM and RIFR were identified between the AP+PCS and the AP+PP group.ConclusionOverall, single column plate plus other column lag screw fixation conferred similar stability to conventional both column plate fixation. From a clinical point of view, AP+PCS appears to be the most attractive alternative to conventional AP+PP for internal fixation of ACPHT fractures.     

Biomechanics of external fixation of distal tibial extra-articular fractures: is spanning the ankle with a foot plate desirable?

OBJECTIVES: To compare the mechanical stability of external fixation with and without spanning of the ankle joint with a foot plate in an in vitro model of extra-articular distal tibia fractures. DESIGN: A laboratory investigation was performed to evaluate the mechanical behavior of external fixation of extra-articular distal tibia fractures using a fixator with and without a foot plate. Ten fresh-frozen lower extremities (5 pairs) with a simulated OTA 43-A3.3 fracture were stabilized with an Ilizarov hybrid fixator with and without a foot plate. SETTING: All mechanical testing was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). MAIN OUTCOME MEASUREMENT: Deformation characteristics as a function of load were compared for an Ilizarov fixator with and without a foot plate under identical conditions of forefoot loading from 0 to 100 N. Relative interfragmentary motions (vertical and horizontal translations and rotation) were measured. RESULTS: There was significantly more vertical translation (2.57 +/- 0.97 mm vs. -0.83 +/- 0.64 mm) and angular displacement (4.49 +/- 0.45 degrees vs. -1.15 +/- 0.61 degrees ) of the distal fragment in the arrangement without a foot plate compared with the construct with a foot plate. The anterior translation of the distal fragment was similar with (1.12 +/- 0.98 mm) and without a foot plate (1.19 +/- 1.23 mm). CONCLUSIONS: This study supports the mechanical importance of spanning of the ankle with a foot plate in most cases of external fixation for unstable extra-articular and periarticular distal tibia fractures. Further studies are needed to validate these results before widespread changes in clinical treatment can be recommended.     

Can tape–screw fixation of a quadrupled semitendinosus graft in a full-length tibial tunnel provide superior fixation compared with a doubled semitendinosus–gracilis held with an interference screw? A matched-pair cadaveric biomechanical comparison

Background

In anterior cruciate ligament reconstruction, quadrupled semitendinosus (Quad ST) grafts have potential advantages over doubled semitendinosus–gracilis (ST/G) including larger diameter and gracilis preservation, however the ideal tibial fixation method of the resultant shorter Quad ST graft remains elusive if a fixed-loop suspensory fixation device is used on the femur. We investigated whether the tibial fixation biomechanical properties of a Quad ST fixed indirectly with polyethylene terephthalate tape tied over a screw in a full outside-in created tunnel was superior to a ST/G graft fixed with an interference screw.

Materials and methods

In a controlled laboratory study, six cadaveric matched pairs of each construct were subjected to cyclic loading to mimic physiologic loading during rehabilitation. This included preconditioning cycling, cyclic loading to 220 N for 500 cycles, then cyclic loading to 500 N for 500 cycles.

Results

High standard deviations across the measured parameters occurred with no significant difference between measured parameters of elongation for the different constructs. Elongation of the Quad-ST construct was greater at 10 and 100 cycles, but not statistically different. Four of the six Quad-ST constructs failed below 100 cycles, compared with two failures below 100 cycles in the ST/G construct. There was a strong correlation between cycles to failure and bone mineral density for the Quad ST-tape constructs.

Conclusions

Tibial fixation of Quad ST with a tied tape–screw construct in a full-length tunnel was not biomechanically superior to ST/G graft fixed with an interference screw, exhibited greater nonsignificant construct elongation with earlier failure, and was more reliant on bone mineral density.

Level of evidence

In vitro laboratory study.

     

Is screw divergence in femoral bone-tendon-bone graft fixation avoidable in anterior cruciate ligament reconstruction using a single-incision technique? A radiographically controlled cadaver study

Summary: Interference screw fixation of patellar tendon bone-tendon-bone grafts for anterior cruciate ligament reconstruction has proven to be a method with high pullout strength if screw divergence is avoided. Twenty-four fresh-frozen cadaveric human knees were used to identify the ideal position for a portal and an optimal knee flexion angle to obtain parallel placement of screw and bone block. On all specimens, anterior cruciate ligament reconstruction was performed using a single-incision technique. In the first part of this study, screw placement was analyzed in the frontal plane. In the second part, screw placement was investigated in the sagittal plane, measuring the additional flexion required between femoral tunnel drilling (at 60° of knee flexion) and screw insertion to obtain parallel screw placement. For both part I and II, image intensification was used. In the third part, femoral screw placement was carried out through a paraligamentous approach and with additional flexion of 10°, 20°, 30°, 40°, 50°, and 60°. This study shows that screw placement with minimal divergence in the frontal and sagittal planes can be achieved by inserting the screw through a nearly central portal and flexing the knee an additional 35° to 40°.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 6 (September), 2000: pp 640–647     

Fewer reoperations after posterolateral plate positioning compared with lateral plate positioning in ankle fractures—a retrospective study on 453 AO/OTA 44-B injuries

IntroductionAnkle fractures are commonly treated by open reduction and internal fixation with plate and screws. Unplanned return to theatre is common, in many cases to extract prominent osteosynthesis material from the lateral malleolus as swelling subsides. We hypothesised that patients operated with a posterolateral plate placement on the lateral malleolus would have fewer reoperations, and fewer complications, compared to patients with a lateral plate placement.Materials and MethodsFrom a prospectively collected database of all orthopaedic surgery performed at our institution, we identified 664 ankle fractures undergoing plate fixation between 2008-01-01 and 2012-04-30. Radiographs were analysed to only include AO/OTA 44-B-fractures (n = 453), and to define study groups based on plate positioning. Hospital files were assessed to identify possible confounding factors, and any unplanned reoperation or complication. Complications were classified according to Dindo-Clavien.ResultsThe risk of reoperation was 13% after posterolateral plating, compared with 24% after lateral plating; absolute risk reduction 10% (95% CI: 2.5–18), p = 0.02. After adjusting for possible confounders, the odds ratio of undergoing reoperation after lateral plating was 2.2 (95% CI: 1.17–4.1), p = 0.01. The two surgical methods did not differ with regard to complication frequency: 31% vs 34%, p = 0.6, but complications following lateral plate fixation were more serious, p = 0.03. Plate positioning depended on surgeon preference.DiscussionThe two studied methods are both considered standard treatment of ankle fractures, and relatively simple surgical procedures. High rates of secondary surgery after plate fixation have been reported, but no study comparing plate positioning has been previously published to our knowledge. AO Sweden has recently switched to teaching posterolateral plating in group exercises during the AO Basic Fracture Surgery course, based on the belief that it may be safer than lateral plating. Our findings support this change in practice.ConclusionsPosterolateral plate positioning on the lateral malleolus in AO/OTA 44-B-fractures may be preferential to lateral plate positioning, due to a large difference in unplanned secondary surgery.     

Percutaneous short-segment pedicle screw placement without fusion in the treatment of thoracolumbar burst fractures: is it effective?: comparative study with open short-segment pedicle screw fixation with posterolateral fusion

Background

Since introduction of the pedicle screw-rod system, short-segment pedicle screw fixation has been widely adopted for thoracolumbar burst fractures (TLBF). Recently, the percutaneous pedicle screw fixation (PPSF) systems have been introduced in spinal surgery; and it has become a popularly used method for the treatment of degenerative spinal disease. However, there are few clinical reports concerning the efficacy of PPSF without fusion in treatment of TLBF. The purpose of this study was to determine the efficacy and safety of short-segment PPSF without fusion in comparison to open short-segment pedicle screw fixation with bony fusion in treatment of TLBF.

Methods

This study included 59 patients, who underwent either percutaneous (n?=?32) or open (n?=?27) short-segment pedicle screw fixation for stabilization of TLBF between December 2003 and October 2009. Radiographs were obtained before surgery, immediately after surgery, and at the final follow-up for assessment of the restoration of the spinal column. For radiologic parameters, Cobb angle, vertebral wedge angle, and vertebral body compression ratio were assessed on a lateral thoracolumbar radiograph. For patient’s pain and functional assessment, the visual analogue scale (VAS), the Frankel grading system, and Low Back Outcome Score (LBOS) were measured. Operation time, and the amount of intraoperative bleeding loss were also evaluated.

Findings

In both groups, regional kyphosis (Cobb angle) showed significant improvement immediately after surgery, which was maintained until the last follow up, compared with preoperative regional kyphosis. Postoperative correction loss showed no significant difference between the two groups at the final follow-up. In the percutaneous surgery group, there were significant declines of intraoperative blood loss, and operation time compared with the open surgery group. Clinical results showed that the percutaneous surgery group had a lower VAS score and a better LBOS at three months and six months after surgery; however, the outcomes were similar in the last follow-up.

Conclusions

Both open and percutaneous short-segment pedicle fixation were safe and effective for treatment of TLBF. Although both groups showed favorable clinical and radiologic outcomes at the final follow-up, PPSF without bone graft provided earlier pain relief and functional improvement, compared with open TPSF with posterolateral bony fusion. Despite several shortcomings in this study, the result suggests that ongoing use of PPSF is recommended for the treatment of TLBF.     

Mesh fixation with fibrin glue (Tissucol/Tisseel®) in hernia repair dependent on the mesh structure—is there an optimum fibrin–mesh combination?—Investigations on a biomechanical model

Background  

Because of its hemostatic and adhesive properties, fibrin glue has been used in many areas of surgical treatment in recent years. One example is hernia repair, where fibrin gluing has become increasingly established as an alternative method for mesh fixation. Clinically, fixation with fibrin glue shows a reduced postoperative complication rate compared to other fixation methods (staples, sutures), particularly with regard to pain.     

How far is the preoperative Kattan nomogram applicable for the prediction of recurrence after prostatectomy in patients presenting with PSA levels of more than 20 ng/ml? A validation study

OBJECTIVE: We present an external validation study investigating the applicability of the preoperative Kattan nomogram for predicting recurrence after prostatectomy in a population of patients with serum prostate-specific antigen (PSA) levels exceeding 20 ng/ml. MATERIALS: In the evaluation of clinical parameters pooled from a total of 191 patients presenting with PSA levels ranging between 20.1 and 100 ng/ml, the PSA-free survival rate 60 months after surgery was calculated according to Kattan nomograms. Subsequently, the results were statistically compared with the corresponding actual survival rates obtained from Kaplan-Meier analysis. For this purpose, the patients were assigned to one of four different risk groups according to predictions derived from the Kattan nomograms, enabling a direct comparison of expected (as predicted by Kattan nomogram) versus actual survival of each patient investigated in our study. RESULTS: Predicted PSA-free survival rates were determined to be as follows: 83% (low risk group); 66% (intermediate risk group); 39% (intermediate-high risk group), and 10% (high risk group) in comparison with the actual survival rates determined to be 63, 62, 40 and 21%, respectively. For PSA levels ranging between 20.1 and 30 ng/ml, 30.1 and 50 ng/ml, and 50.1 and 100 ng/dl, PSA-free survival rates were found to be 57, 37, and 27% (p=0.0017), respectively, during a 5-year post-prostatectomy follow-up. CONCLUSIONS: The Kattan nomogram shows good statistical concordance with actual survival rates in the mean risk quadrants, but considerable differences were demonstrated concerning individuals with either a high or with a low risk of cancer progression.     

Are patients with a nonunion after a femoral neck fracture more osteoporotic than others? BMD measurement before the choice of treatment?: A pilot study of hip BMD and biochemical bone markers in patients with femoral neck fractures

The incidence of nonunion is high after a femoral neck fracture. If reliable predictors were available, fractures that heal well could be subjected to internal fixation while fractures that do not could undergo an arthroplasty. In this pilot study of 28 patients, those with a low hip BMD on admission had a higher risk of developing non-union.     

Do rheumatoid arthritis patients have low back pain or radiological lumbar lesions more frequently than the healthy population? – Cross-sectional analysis in a cohort study with age and sex-matched healthy volunteers

BACKGROUND CONTEXTRheumatoid arthritis (RA) can affect the spine; however, the epidemiology of lumbar lesions and/or low back pain (LBP) in RA patients has not been well-studied.PURPOSEThe purpose of this study was to compare the prevalence of lumbar lesions and LBP in RA patients with that in healthy volunteers, and to elucidate the influence of RA on lumbar disease.STUDY DESIGNCross-sectional analysis in a cohort study with age- and sex-matched healthy volunteers.PATIENT SAMPLEThis study included 185 patients with RA and 188 gender/age-matched healthy volunteers without RA.OUTCOME MEASURESLumbar spondylolisthesis and prevalent vertebral fractures were evaluated using plain lateral X-ray images. Thoraco-lumbar scoliosis was evaluated using dual-energy X-ray absorptiometric images. LBP was assessed using the visual analogue scale (VAS) and Rolland-Morris disability questionnaire (RDQ).METHODSThe prevalence of radiological lumbar lesion and LBP was compared between the RA and control groups. In the RA group, factors associated with lumbar lesion and LBP were analyzed using a multiple logistic regression model.RESULTSThe prevalence rates of spondylolisthesis and prevalent vertebral fracture were significantly higher in the RA group than in the control group; the prevalence of thoraco-lumbar scoliosis tended to be higher in the RA group. There was no significant difference in the average LBP-VAS between the groups. However, the percentage of analgesic drug use was significantly higher, and RDQ scores tended to be worse in the RA group than the control group. Multivariate analysis revealed that age and disease activity score were both related to LBP in the RA group.CONCLUSIONSRA patients are more likely to have radiological lumbar lesions. LBP in RA patients is well controlled, similar to the level in the healthy population; however, disease activity was related to LBP in RA patients. These results suggest that disease control is important for lumbar care in RA patients.     

Repetitive H-Wave? device stimulation and program induces significant increases in the range of motion of post operative rotator cuff reconstruction in a double-blinded randomized placebo controlled human study

Background  

Albeit other prospective randomized controlled clinical trials on H-Wave Device Stimulation (HWDS), this is the first randomized double-blind Placebo controlled prospective study that assessed the effects of HWDS on range of motion and strength testing in patients who underwent rotator cuff reconstruction.     

Rapid closure of midgestational excisional wounds in a fetal mouse model is associated with altered transforming growth factor-β isoform and receptor expression

Background

Many pediatric diseases are characterized by excessive tissue contraction. Because of a poor understanding of contraction, few therapies exist. We developed a murine fetal excisional wound model of contraction and theorize that wound closure is associated with changes in transforming growth factor-β (TGF-β) expression.

Methods

Pregnant FVB mice underwent hysterotomy at midgestational (E15) or late-gestational (E18) ages. Three-millimeter excisional wounds were made in fetuses and harvested at 32 hours. Real-time polymerase chain reaction was performed for TGF-β1, TGF-β2, TGF-β3, TβR-1, and TβR-2 in wounds and normal skin and normalized to glyceraldehyde-3-phosphate dehydrogenase. Data were analyzed by paired t test (P < .05). H&E staining of wounds was performed.

Results

E15 wounds (80.5% ± 4.4%) were smaller than E18 wounds (10.4% ± 10.5%; P < .001) at 32 hours. E15 wounds expressed higher levels of TGF-β1 compared with normal skin (P = .001). TβR-2 levels were elevated in E15 and E18 wounds compared with their respective normal skin (P = .02, P = .01) and in E18 normal skin compared with E15 normal skin (P = .002).

Conclusion

This study demonstrates that rapid midgestational wound closure in a murine model is associated with increased TGF-β1 and TβR-2 expression. Elucidating the role of the TGF-β pathways may lead to an improved understanding of wound contraction.