Low-profile double plating versus dorsal LCP in stabilization of the olecranon fractures

INTRODUCTION

Proximal ulna fractures are common in orthopaedic surgery. Comminuted fractures require a high primary stability by the osteosynthesis, to allow an early functional rehabilitation as fast as possible, to reduce long-term limitations of range of motion. Classical dorsal plating is related to wound healing problems due to the prominence of the implant. New low-profile double plates are available addressing the soft tissue problems by positioning the plates at the medial and lateral side. This study analysed whether, under high loading conditions, these new double plates provide an equivalent stability as compared to the rigid olecranon locking compression plate (LCP).

MATERIALS AND METHODS

In Sawbones, Mayo Type IIB fractures were simulated and stabilized by plate osteosyntheses: In group one, two low-profile plates were placed. In group two, a single dorsal plate (LCP) was used. The bones was than cyclically loaded simulating flexion grades of 0°, 30°, 60° and 90° of the elbow joint with increasing tension forces (150 , 150 , 300  and 500 N). The displacement and fracture gap movement were recorded. In the end, in load-to-failure tests, load at failure and mode of failure were determined.

RESULTS

No significant differences were found for the displacement and fracture gap widening during cyclic loading. Under maximum loading, the double plates revealed a comparable load at failure like the single dorsal plate (LCP). The double plates failed with a proximal screw pull-out of the plate, whereas in the LCP group, in 10 out of 12 specimens the mode of failure was a diaphyseal shaft fracture at the distal plate peak.

CONCLUSION

Biomechanically, the double plates are a good alternative to the dorsal LCP providing a high stability under high loading conditions and, at the same, time reducing the soft tissue irritation by a lateral plate position.

Clinical implications of fracture-associated vascular damage in extremity and pelvic trauma

BACKGROUND

Vascular damage in polytrauma patients is associated with high mortality and morbidity. Therefore, specific clinical implications of vascular damage with fractures in major trauma patients are reassessed.

METHODS

This comprehensive nine-year retrospective single center cohort study analyzed demography, laboratory, treatment and outcome data from 3689 patients, 64 patients with fracture-associated vascular injuries were identified and were compared to a control group.

RESULTS

Vascular damage occurred in 7% of patients with upper and lower limb and pelvic fractures admitted to the trauma room. Overall survival was 80% in pelvic fracture and 97% in extremity fracture patients and comparable to non-vascular trauma patients. Additional arterial damage required substantial fluid administration and was visible as significantly anemia and disturbed coagulation tests upon admission. Open procedures were done in over 80% of peripheral extremity vascular damage. Endovascular procedures were predominant (87%) in pelvic injury.

CONCLUSION

Vascular damage is associated with high mortality rates especially in combination with pelvic fractures. Initial anemia, disturbed coagulation tests and the need for extensive pre-clinical fluid substitution were observed in the cohort with vascular damage. Therefore, fast diagnosis and early interventional and surgical procedures are necessary to optimize patient-specific outcome.

Grade of retraction and tendon thickness correlates with MR-spectroscopically measured amount of fatty degeneration in full thickness supraspinatus tears

Background

The amount of fatty degeneration (FD) has major impact on the clinical result and cuff integrity after rotator cuff repair. A quantitative analysis with magnet resonance imaging (MRI) spectroscopy was employed to analyze possible correlation of FD with tendon retraction, tendon thickness and patients’ characteristics in full thickness supraspinatus tears.

Methods

Forty-two patients with full-thickness supraspinatus tears underwent shoulder MRI including an experimental spectroscopic sequence allowing quantification of the fat fraction in the supraspinatus muscle belly. The amount of fatty degeneration was correlated with tendon retraction, tendon thickness, patients’ age, gender, smoker status, symptom duration and body mass index (BMI). Patients were divided in to three groups of retraction (A) 0-10 mm (n=), (B) 11-20 mm (n=) and (C) < 21 mm (n=) and the means of FD for each group were calculated.

Results

Tendon retraction (R = 0.6) and symptom duration (R = 0.6) correlated positively, whereas tendon thickness correlated negatively (R = − 0.6) with the amount of FD. The fat fraction increased significantly with tendon retraction: Group (A) showed a mean fat mount of 3.7% (±4%), group (B) of 16.7% (±8.2%) and group (C) of 37.5% (±19%). BMI, age and smoker-status only showed weak to moderate correlation with the amount of FD in this cohort.

Conclusion

MRI spectroscopy revealed significantly higher amount of fat with increasing grade of retraction, symptom duration and decreased tendon thickness. Thus, these parameters may indirectly be associated with the severity of tendon disease.

Quantitative MRI comparison of multifidus muscle degeneration in thoracolumbar fractures treated with open and minimally invasive approach

Background

Minimally invasive pedicle screw fixation has less approach-related morbidity than open screw placement and is allegedly less traumatizing on paravertebral muscles, as there is no requirement to mobilize and retract the adjacent muscle portion. The approach-related long-term effects to the morphology of the paravertebral muscles are unknown. The purpose of this study was to compare the long-term amount of fatty degeneration of the multifidus muscle in patients treated with a classical open or a minimally invasive approach.

Methods

Fourteen Patients meeting inclusion criteria were selected. In all patients a singular fracture of the thoracolumbar spine with a two-level posterior instrumentation was treated, either using an open approach or a minimally invasive approach. All patients underwent quantitative MRI spectroscopy for quantification of the fatty degeneration in the multifidus muscle as a long-term proof for muscle loss after minimum 4-year follow-up. Clinical outcome was assessed using Oswestry Low Back Pain Disability Questionnaire, SF-36 and VA-scale for pain.

Results

The minimally invasive approach group failed to show less muscle degeneration in comparison to the open group. Total amount of fatty degeneration was 14.22% in the MIS group and 12.60% in the open group (p = 0.64). In accordance to MRI quantitative results there was no difference in the clinical outcome after a mean follow up of 5.9 years (±1.8).

Conclusion

As short-term advantages of minimal invasive screw placement have been widely demonstrated, no advantage of the MIS, displaying a significant difference in the amount of fatty degeneration and resulting in a better clinical outcome could be found. Besides the well-known short-term advantage of minimally invasive pedicle screw placement, a long-term advantage, such as less muscle degeneration and thus superior clinical results, compared to the open approach could not be shown.

Six Sesamoid Bones on Both Feet: Report of a Rare Case

There is a variation of the total number of distinct bones in the human in the literature. This difference is mainly caused by the variable existence of sesamoid bones. Sesamoid bones at the first MTP are seen regularly. In contrast additional sesamoid bones at the second to fifth MTP are rare. We report a case of additional sesamoid bones at every metatarsophalangeal joint (MTP) of both feet. A 22-year-old female Caucasian presented with weight-dependent pain of the second MTP of the left foot. In the radiographs of both feet additional sesamoid bones at every MTP could be seen. This case reports a very rare variation in human anatomy. A similar case has not been displayed to the academic society and therefore should be acknowledged.

Surgical adhesive BioGlue™ does not benefit tendon repair strength: an ex vivo study

Surgical adhesives are useful supplements in surgery, but their benefit in tendon repair is uncertain. The purpose of this study was to evaluate the effect of BioGlue™ on strength of flexor tendon repair. A total of 60 porcine flexor tendons were divided into three groups. In group one, a conventional core and peripheral suture repair was used. In group two, a core suture and BioGlue™ were used. In group three, a conventional core and peripheral suture repair and BioGlue™ were used. We performed static and cyclic axial load testing and measured diameter of the repair site. We found that BioGlue™ did not improve the tensile strength when added to a core and peripheral suture and that there was an increase in bulk at the repair site. We conclude that BioGlue™ application cannot replace a peripheral suture as tensile strength significantly decreases without a peripheral suture, and it does not benefit a tendon already repaired with a core and peripheral suture.

LEVEL OF EVIDENCE

n/a.

[Artificial synostosis for traumatic metacarpal defect: a case report]

Reconstruction of traumatic metacarpal defects is still challenging because of the key function of the architecture of the metacarpus for the function of the entire hand. Especially the exact restoration of the rotation for a parallel finger movement plays an important role. There are less information on this topic in the literature. We present a 28-year old patient with a traumatic almost complete defect of the fourth metacarpal. Reconstruction of the metacarpal arch was achieved with an artificial synostosis between the intact head of the 4th metacarpal and the 3rd metacarpal.

Tensile strength of flexor tendon repair using barbed suture material in a dynamic ex vivo model

The purpose of this study was to compare two sutures; a knotted polydioxane with a knotless barbed in a 4-strand Kirchmayr-Kessler suture technique. Human flexor digitorum tendons were separated into four groups. Group 1 - polydioxane; Group 2 - barbed suture; Group 3 and 4 - same as group 1 and 2 with an additional peripheral running suture. In each group the repaired tendons were subjected to linear and cyclical loads. No difference in maximum tensile strength after linear and cyclical force could be detected between the knotted polydioxane suture and the knotless barbed suture. On linear force tests an additional circumferential repair increased the maximum tensile strength of both sutures. Cyclical force loading did not lead to a reduction of maximum strength. Following linear and cyclical loading the 4-strand barbed suture achieved maximum tensile strengths comparable to the 4-strand repair using the polydioxane suture. Barbed suture repair may offer the advantage of knotless suture techniques.

Reconstruction of the thumb tip using palmar neurovascular flaps

OBJECTIVE

Reconstruction of the tip of the thumb using a neurovascular flap.

INDICATIONS

Transverse defects of the thumb's tip or large defects of the palmar pulp (max. 2.0-2.5 cm) with exposure of bone and/or tendons.

CONTRAINDICATIONS

Extensive crush injury, heavy wound contamination, circulatory disorders, acute infection, very large defects (> 2.0-2.5 cm finger length), circumferential soft tissue defects, and previous defects/operations (relative).

SURGICAL TECHNIQUE

Supine position, hand supinated, tourniquet, loupe magnification. Mid-lateral incisions along both sides of the finger running from the defect to the interphalangeal joint (small defect) or proceeding further proximally. Careful elevation of the flap including both neurovascular bundles leaving dorsal branches of the bundles (long fingers only) and the flexor tendon sheath intact. Suture of the flap in either flexion position (i.e., advancement flap) (Moberg) or by creating an island-flap through an additional transverse skin incision along the flap's base (O'Brien). Finally, closure of the defect at the flap's base using a full thickness skin graft, Z plasty, or V-Y plasty.

POSTOPERATIVE MANAGEMENT

Plaster cast (finger slightly flexed) for 2 weeks.

RESULTS

Reliable method. Good functional results with good sensibility and only minor reduction in range of motion.

Experimental fracture model versus osteotomy model in metacarpal bone plate fixation

Introduction. Osteotomy or fracture models can be used to evaluate mechanical properties of fixation techniques of the hand skeleton in vitro. Although many studies make use of osteotomy models, fracture models simulate the clinical situation more realistically. This study investigates monocortical and bicortical plate fixation on metacarpal bones considering both aforementioned models to decide which method is best suited to test fixation techniques. Methods. Porcine metacarpal bones (n = 40) were randomized into 4 groups. In groups I and II bones were fractured with a modified 3-point bending test. The intact bones represented a further control group to which the other groups after fixation were compared. In groups III and IV a standard osteotomy was carried out. Bones were fixated with plates monocortically (group I, III) and bicortically (group II, IV) and tested for failure. Results. Bones fractured at a mean maximum load of 482.8 N ± 104.8 N with a relative standard deviation (RSD) of 21.7%, mean stiffness was 122.3 ± 35 N/mm. In the fracture model, there was a significant difference (P = 0.01) for maximum load of monocortically and bicortically fixed bones in contrast to the osteotomy model (P = 0.9). Discussion. In the fracture model, because one can use the same bone for both measurements in the intact state and the bone-plate construct states, the impact of inter-individual differences is reduced. In contrast to the osteotomy model there are differences between monocortical and bicortical fixations in the fracture model. Thus simulation of the in vivo situation is better and seems to be suitable for the evaluation of mechanical properties of fixation techniques on metacarpals.

[Percutaneous screw osteosynthesis of femoral neck fractures in the elderly. Subtrochanteric fractures as severe complications]

Percutaneous osteosynthesis by cannulated screws is a well established method for the treatment of non-displaced femoral neck fractures, especially in elderly patients with comorbidities due to low operative invasiveness. Optimal screw placement is still under discussion. There are only few literature references concerning the complication of subtrochanteric femoral fractures. We performed a review of the literature and a retrospective analysis of our patients treated by this form of osteosythesis from 01.04.2004 to 30.09.2009 searching for screw placement and the incidence of subtrochanteric femoral fractures. This complication was found in 2 of our 35 patients (5.7%) without adequate trauma, such as a stumble or fall having occurred.

Ist die Behandlung der instabilen distalen Radiusfraktur beim älteren Menschen mittels Fixateur externe nicht mehr indiziert?

BACKGROUND

In recent years there has been an increasingly marked shift in the operative treatment of unstable fractures of the distal radius. The introduction of locking compression plates has made it possible to extend the indications for palmar stabilisation according to the principles of internal fixation to extension fractures even in osteoporotic bone, and since then the new design has been used more and more widely. First clinical results show very good and good clinical and radiological outcomes in over 80% of cases after locking compression plate osteosynthesis. All this raises the question of whether external fixation is no longer indicated for distal radius fractures in the elderly, or is now no more than a second-line treatment.

PATIENTS AND METHODS

Within a 5-year period, 67 patients over 65 years of age were identified among 220 who had had unstable fractures of the distal radius in our hospital with external fixation. The average follow-up period (clinical and radiological examinations) was 37 months. We devoted particular attention to the analysis of complications and problems during the treatment.

RESULTS

Complete bone healing was observed in all patients treated with external fixation. In most cases, complications were minor pin-track infections (10%). The radiological follow-up examination revealed radial shortening by an average of 2 mm and an average radial shift of 0.2 mm. The joint angle was 2.5 degrees with lateral irradiation and 18 degrees with dorso-palmar irradiation. According to the Gartland and Werley score, the functional, radiological and subjective outcome was excellent or good in 87% of these patients.

CONCLUSIONS

Overall, internal fixation with angular fixed plates has definite benefits. The medium- and long-term follow-up and functional outcome still show no benefits over external fixation, however. External fixation is a genuine option, even if as second-line treatment.

[Rupture of the quadriceps tendon. Diagnosis and treatment of a rare injury]

Rupture of the quadriceps tendon is a rare knee injury. In most cases the tendon ruptures spontaneously without adequate trauma in patients older than 40 years with degenerative changes of the tendon. Suture repair is the only treatment option for acute complete, older ruptures and partial ruptures that do not heal after nonoperative treatment. The type of repair depends on the time of diagnosis and localisation of the rupture. The functional outcome depends on timely repair and early initiation of knee movement and strengthening therapy.

Extraoss�re Kalzifikationen bei Dermatomyositis

Juvenile dermatomyositis is rare but still the most common idiopathic inflammatory myopathy of the childhood. Operative treatment may be indicated, whenever joint motion and patients mobility is limited through the manifestation of calcinosis cutis. Although Vitamin K dependent coagulation pathways have been described, the entire pathophysiological mechanism of its occurrence is currently not clarified. Standard therapy includes the systemic application of steroids and cytotoxins, other options involve aluminum-hydroxid or diltiazem. Only in serious functional obstructions operative resection may be indicated. The case of a 39-year-old female with a 24 year history of dermatomyositis involving most areas of the upper and lower extremities like a coat of mail is presented. Surgical resection of the calcification revealed a good functional recovery of the joint but because of a high recurrency rate the operation is only indicated in special cases.

Primary resective shortening followed by distraction osteogenesis for limb reconstruction: a comparison with simple lengthening

Resective distraction osteogenesis is a new approach to treat segmental diaphyseal bone defects by primary limb shortening and secondary distraction osteogenesis from the same site. A rabbit model was introduced to compare the bone-regeneration characteristics of this technique with those of simple lengthening procedures. Twenty-four skeletally mature New Zealand White rabbits were divided into two equal groups. In the test group, limbs were lengthened after a 10-mm segmental diaphyseal bone resection and limb shortening. In the control group, a simple subperiosteal osteotomy for limb lengthening was performed without resection. New bone formation was evaluated mechanically, radiologically, histomorphometrically, and densitometrically. Bone bridging occurred in all animals. Normalized mechanical values for the newly reconstructed tibiae demonstrated similar torsional stiffness (71+/-3.3 compared with 71+/-8.2%; p = 0.95) and strength (64+/-5.3 compared with 68+/-7.3%; p = 0.66) in the two groups. The average normalized callus diameter was significantly greater in the test group than in the control group (p < 0.01). The remodeling index calculated from densitometry, however, showed a significantly less progressed stage of remodeling in the test group (p < 0.05). Histomorphometric analysis of the callus center supported this finding, showing significantly lower values for trabecular thickness (p < 0.05) and total bone volume (p < 0.01) in the test group. The results demonstrated the possibility of new bone formation after resection and monofocal shortening. This suggests a new therapeutic option to treat diaphyseal segmental bone defects.

Distraction osteogenesis after acute limb-shortening for segmental tibial defects. Comparison of a monofocal and a bifocal technique in rabbits

BACKGROUND

Segmental bone defects can be treated with immediate limb-shortening followed by monofocal or bifocal distraction osteogenesis. In the present study, the efficacy of monofocal distraction osteogenesis was compared with that of bifocal distraction osteogenesis in a rabbit model.

METHODS

Twenty-four skeletally mature New Zealand White rabbits were divided into two equal groups: one group had monofocal distraction osteosynthesis, and the other had bifocal distraction osteosynthesis. In both groups, a one-centimeter-long segment of bone was resected from the midpart of the tibial shaft. In the monofocal reconstruction group, the limb was immediately shortened to close the segmental defect and the defect was allowed to heal for ten days. Lengthening was then begun at this site, with use of a specially designed external fixator, at a rate of 0.5 millimeter per twelve hours. In the bifocal reconstruction group, the segmental defect was closed immediately and the fragments were fixed with microplates. A subperiosteal osteotomy was performed proximal to the tibiofibular junction, and lengthening was performed at the site of the osteotomy. The animals in both groups were killed twenty days after the lengthening was completed. New-bone formation then was evaluated with use of radiographs, densitometry, biomechanical testing, and histological and histomorphometric analysis.

RESULTS

Osseous consolidation occurred in all but one of the animals. Biomechanical testing demonstrated that the tibiae that had been treated with use of the simple monofocal reconstruction technique tended to have greater torsional stiffness (p = 0.14) and strength (p = 0.09). Follow-up radiographs revealed that both groups had a significant decrease in radiolucent area (p < 0.05), which occurred at essentially the same rate after lengthening. No significant differences were found between the groups with respect to new-bone mineral density, new-bone area, or the amount of callus. Thus, after resection of a diaphyseal bone segment comprising 10 percent of the original length of the tibia and acute shortening, limb reconstruction was completed successfully through distraction osteogenesis with use of either a monofocal or a bifocal technique in rabbits.

CONCLUSIONS

In the present study, both monofocal and bifocal techniques of shortening and distraction osteogenesis were effective for the reconstruction of segmental bone defects. Under some conditions, the monofocal method may provide a simpler means of treating such defects.

CLINICAL RELEVANCE

Damage to the soft-tissue envelope as well as venous and lymphatic stasis impose limits on the amount of limb-shortening that can be achieved with use of the monofocal method and also influence the indications for this procedure in the clinical setting.

Comparison of two systems for tibial external fixation in rabbits

BACKGROUND AND PURPOSE

Use of rabbits in orthopedic investigations is common. In this study, focus is on factors that influence bone healing and on distraction osteogenesis. Biomechanical characteristics of two external fixator systems (Orthofix device and Hoffmann device) for long bones were tested.

METHODS

Twelve freshly dissected tibiae were obtained from six skeletally mature New Zealand White rabbits, and four-point bending stiffness in two planes (90 and 180 degrees to the fixator pins) and torsional stiffness and strength of the bone-fixator complex were evaluated by use of a material testing machine.

RESULTS

In four-point bending, Orthofix device had higher stiffness and strength, compared with Hoffmann device. When the load was applied 180 degrees to the pins, both devices had higher stiffness, compared with that at 90 degrees. In torsional testing, Orthofix device had significantly higher stiffness and strength.

CONCLUSIONS

Significant differences in structural properties between the two systems were evident. Loading direction and gap conditions were important factors in determining properties of the systems. Therefore, type of external fixation system and fixation technique should be considered when designing experiments, using the rabbit long bone model.

Bundle nailing in nonunion of the distal radius: case report

A previously unreported technique for dealing with severe distal radial nonunion in the presence of marked osteoporosis and deformity in a 65-year-old female is presented. The technique involves temporary ankylosis of the wrist with bundle nails connecting the second and third metacarpal with the distal and proximal fragment of the radius, dorsal to the carpal bones and joints. Union was achieved radiographically after nine months. When the bundle nails were removed, there was some recovery of wrist movement and useful function.