Biomechanical study of a low-cost external fixator for diaphyseal fractures of long bones.

BACKGROUND: External fixation improves open fracture management in emerging countries. However, sophisticated models are often expensive and unavailable. We assessed the biomechanical properties of a low-cost external fixation system in comparison with the Hoffmann® 3 system, as a reference. METHODS: Transversal, oblique, and comminuted fractures were created in the diaphysis of tibia sawbones. Six external fixators were tested in three modes of loading-axial compression, medio-lateral (ML) bending, and torsion-in order to determine construction stiffness. The fixator construct implies two uniplanar (UUEF1, UUEF2) depending the pin-rods fixation system and two biplanar (UBEF1, UBEF2) designs based on different bar to bar connections. The designed low-cost fixators were compared to a Hoffmann® 3 fixator single rod (H3-SR) and double rod (H3-DR). Twenty-seven constructs were stabilized with UUEF1, UUEF2, and H3-SR (nine constructs each). Nine constructs were stabilized with UBEF1, UBEF2, and H3-DR (three constructs each). RESULTS: UUEF2 was significantly stiffer than H3-SR (p < 0.001) in axial compression for oblique fractures and UUEF1 was significantly stiffer than H3-SR (p = 0.009) in ML bending for transversal fractures. Both UUEFs were significantly stiffer than H3-SR in axial compression and torsion (p < 0.05), and inferior to H3-SR in ML bending, for comminuted fractures. In the same fracture pattern, UBEFs were significantly stiffer than H3-DR (p = 0.001) in axial compression and torsion, while only UBEF1 was significantly stiffer than H3-DR in ML bending (p = 0.013). CONCLUSIONS: The results demonstrated that the stiffness of the UUEF and UBEF device compares to the reference fixator and may be helpful in maintaining fracture reduction. Fatigue testing and clinical assessment must be conducted to ensure that the objective of bone healing is achievable with such low-cost devices.

Biomechanical Assessment of Locking Plate Fixation of Comminuted Proximal Olecranon Fractures.

OBJECTIVES: To determine if mean ultimate strength or failure mechanism differed between comminuted olecranon fractures created at the proximal 25% or 50% of the trochlear notch and fixed with precontoured posterior locking plates (PLPs). METHODS: Comminuted osteotomies were created in 10 matched pairs of cadaveric upper extremities at either the proximal 25% or 50% of the trochlear notch after quantitative computed tomography scans were performed to evaluate bone mineral density. Variable-angle olecranon PLPs were fixed to the specimens. The triceps tendon of each specimen was loaded cyclically and then to failure. Comparison of mean force at failure (displacement >2 mm) was performed using the 2-tailed t test. RESULTS: There were no significant differences in specimen bone mineral density within matched pairs. Nineteen specimens failed by olecranon bisection fracture in the sagittal plane. Specimens in the 25% osteotomy group failed at lower ultimate forces of 808 N (SD ± 474 N) versus 1058 N (SD ± 480 N) in the 50% osteotomy group (P = 0.044). CONCLUSIONS: The ultimate strength of comminuted olecranon fracture fixation with a PLP decreases significantly if the fracture is proximal to the midpoint of the trochlear notch. Fractures proximal to the midpoint of the trochlear notch may benefit from supplemental fixation or suture augmentation to prevent failure, particularly at force ranges higher than those experienced during active elbow range of motion.

Biomechanical Assessment of the Dorsal Spanning Bridge Plate in Distal Radius Fracture Fixation: Implications for Immediate Weight-Bearing.

BACKGROUND: The goal of this study was to compare the biomechanical stability of a 2.4-mm dorsal spanning bridge plate with a volar locking plate (VLP) in a distal radius fracture model, during simulated crutch weight-bearing. METHODS: Five paired cadaveric forearms were tested. A 1-cm dorsal wedge osteotomy was created to simulate an unstable distal radius fracture with dorsal comminution. Fractures were fixed with a VLP or a dorsal bridge plate (DBP). Specimens were mounted to a crutch handle, and optical motion-tracking sensors were attached to the proximal and distal segments. Specimens were loaded in compression at 1 mm/s on a servohydraulic test frame until failure, defined as 2 mm of gap site displacement. RESULTS: The VLP construct was significantly more stable to axial load in a crutch weight-bearing model compared with the DBP plate (VLP: 493 N vs DBP: 332 N). Stiffness was higher in the VLP constructs, but this was not statistically significant (VLP: 51.4 N/mm vs DBP: 32.4 N/mm). With the crutch weight-bearing model, DBP failed consistently with wrist flexion and plate bending, whereas VLP failed with axial compression at the fracture site and dorsal collapse. CONCLUSIONS: Dorsal spanning bridge plating is effective as an internal spanning fixator in treating highly comminuted intra-articular distal radius fracture and prevents axial collapse at the radiocarpal joint. However, bridge plating may not offer advantages in early weight-bearing or transfer in polytrauma patients, with less axial stability in our crutch weight-bearing model compared with volar plating. A stiffer 3.5-mm DBP or use of a DBP construct without the central holes may be considered for distal radius fractures if the goal is early crutch weight-bearing through the injured extremity.

Low-Cost Intra-Articular Distraction Technique Using Kirschner Wires and a Toothed Lamina Spreader.

We describe a low-cost (instrument cost) technique for joint distraction using 2 Kirschner wires and a toothed lamina spreader in lieu of a Hintermann distractor. The described technique allows for temporary intra-articular distraction and visualization and preservation of the articular surface with extra-articular instrumentation. The technique can also allow for closed reduction and percutaneous treatment in cases of soft tissue compromise. Additionally, the technique uses common orthopedic surgical instruments, leading to a minimal learning curve for novice surgeons. We have found this distraction technique to be most effective for intra-articular preparation of hindfoot and midfoot arthrodeses and for navicular fracture reduction.

Construct Choice for the Treatment of Displaced, Comminuted Olecranon Fractures: are Locked Plates Cost Effective?

BACKGROUND: Cost effective implant selection in orthopedic trauma is essential in the current era of managed healthcare delivery. Both locking and non-locking plates have been utilized in the treatment of displaced fractures of the olecranon. However, locking plates are often more costly and may not provide superior clinical outcomes. The primary aim of the present study is to assess the clinical and functional outcomes of olecranon fractures treated with locked and non-locking plate and screw constructs while providing insight into the cost of various implants. METHODS: We performed a retrospective chart review of a single institution database identifying Mayo IIB type olecranon fractures treated surgically from 2003 to 2012. All fractures were treated with either a locked plate or a one-third tubular hook plate construct. Clinical and radiographic outcomes were evaluated. Minimum 6-month follow-up was required. Outcomes were compared between fixation constructs, including rate of union, early failure, postoperative range of motion, and complication rates. Statistical analysis included Pearson's Chi-squared and Fisher's exact test for categorical variables, and the Student's ttest for continuous variables. RESULTS: The one-third tubular construct was equivalent to locking plate constructs with respect to union, post-operative range of motion, and rates of complications. There were no early or late failures. Locking plates were associated with a relative cost increase of $1,263.50 compared to the one-third tubular hook plate per case. CONCLUSION: Surgeons should consider the cost of implants when treating Mayo IIB olecranon fracture. In this cohort, one-third tubular plates provided equivalent outcomes to locked plates with a notable decrease in cost.

Proximal Pole Scaphoid Fractures: A Computed Tomographic Assessment of Outcomes.

PURPOSE: To report on union rates and times for a cohort of acute nondisplaced or minimally displaced proximal pole fractures evaluated with serial computed tomography (CT) scans. METHODS: All patients with isolated acute proximal pole scaphoid fractures (< 6 weeks from injury) who presented at our institution between 2006 and 2013 were identified. Each subject's health record, CT scans (performed at initial assessment and serially to document healing), and x-rays were retrospectively reviewed to determine details of injury, treatment course, and treatment outcome. Union incidence and time to union were determined based on CT scan results. The effect that each predictor variable had on union, nonunion, and delayed union was assessed. RESULTS: This cohort consisted of 53 patients with proximal pole scaphoid fractures (47 males and 6 females; mean age, 30 ± 17 years). The overall union incidence with cast treatment was 90% (47 of 52). The study was underpowered to detect any factors that were predictive of developing a nonunion with cast treatment with the exception of a slight delay to seeking treatment. Average time to union was 14 ± 8 weeks for cases treated with surgical fixation (n = 4; cases that failed casting and were subsequently treated surgically) and 14 ± 12 weeks for cases treated with casting alone. Factors found to be correlated to longer union times included fracture translation (r = 0.30) and the presence of cysts or comminution. CONCLUSIONS: The reported union incidence and union times in this study compared favorably with the literature. Risk factors that were associated with a significantly greater time to union included fracture comminution, the presence of cysts, and fracture translation. Our sample size was relatively small, and other limitations inherent in the retrospective design must be considered. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Three-dimensional suitability assessment of three types of osteochondral autograft for ulnar coronoid process reconstruction.

BACKGROUND: Osteochondral autografts with use of the olecranon tip, lateral radial head, or proximal radial head have been employed for coronoid process reconstruction. However, it is unclear which autograft is most suitable for coronoid articular configuration. We assessed 3-dimensional articular facet suitability of 3 osteochondral autografts for coronoid process reconstruction. METHODS: We performed 3-dimensional computed tomography of 20 elbows to compare the articular facet configuration between the coronoid process and the ipsilateral olecranon tip, lateral radial head, and proximal radial head. We measured the area of the proximity region (≤2.0 mm) between the articular facets of the coronoid process and 3 osteochondral autografts, the covering rate defined as the percentage area of the coronoid articular facet occupied by the proximity region, the location of the proximity region center, and the percentage of the removed ulnohumeral articular facet. RESULTS: The covering rate was significantly higher with an olecranon graft than with radial head grafts. The regional center of a proximal radial head graft was significantly medial compared with that of olecranon and lateral radial head grafts. The olecranon graft used an average of 13.8% of the ulnohumeral articular facet. CONCLUSIONS: An olecranon graft was most suitable for defects of the coronoid process involving the tip, and a proximal radial head graft was most suitable for defects of the coronoid process involving the anteromedial rim. The use of an olecranon graft for reconstruction of 50% of the height of the coronoid process does not cause concern for gross elbow instability.

Assessment of the role of fibular fixation in distal-third tibia-fibula fractures and its significance in decreasing malrotation and malalignment.

BACKGROUND: In the treatment of distal-third tibia/fibula fractures treated by interlocking nailing, the role of fibular fixation is not clearly defined. This study aimed to assess the benefits of fibular fixation in such fractures. METHODS: Sixty patients with fractures of the lower third of the leg were enrolled into the study and divided into two groups based on whether the fibula was fixed (group A) or not (group B). Fracture tibia was treated with interlocked intramedullary nailing and fibular fixation was done using a 3.5-mm Limited Contact Dynamic Compression Plate (LC-DCP). The two groups were compared for differences in rotation at ankle, angulation at the fracture site, time of union and complications. Clinical and functional outcomes were assessed regularly. Merchant-Dietz criteria were used to assess ankle function. RESULTS: The demographics of the two groups were similar. Average valgus angulation was significantly less in group A (average 5°) versus group B (average 9°). The degree of rotational malalignment at the ankle in group A was average 7° versus average 15° in group B. The outcome of two groups for clinical ankle score, time of union and complications showed no significant differences. CONCLUSION: Fixation of the fibula along with interlocking nailing of the tibia decreases the malalignment of the tibia and malrotation of the ankle in distal-third fractures of the tibia and fibula as compared with only interlocking nailing.

Digital surgical templates for managing high-energy zygomaticomaxillary complex injuries associated with orbital volume change: a quantitative assessment.

PURPOSE: This study sought to introduce 3-dimensional (3D) virtual surgical planning and digital rapid-prototyping templates for zygomaticomaxillary complex (ZMC) injuries associated with orbital volume change and to evaluate the surgical outcomes quantitatively. PATIENTS AND METHODS: Eight patients who underwent open reduction and fixation for a ZMC injury with orbital volume change were studied. Computed tomographic (CT) scan of the zygomaticomaxillary area was performed before the operation in each case. Scanned data were converted into 3D models using Mimics software (Materialise, Brussels, Belgium) for surgical designs. Virtual surgical reductions and correlated guiding templates were designed using Mimics and Magics software (Materialise). The operations were performed with the help of prefabricated templates to reduce the fractures. A postoperative CT scan of each patient was obtained within 2 weeks after surgery, and quantitative measurements were made to assess the surgical outcomes. Preoperative volumes of the bilateral orbits were compared, and concordance with postoperative volumes of the bilateral orbits was assessed. Twenty-one pairs of distances from 7 marker points to 3 reference planes were measured to assess postoperative facial symmetry. RESULTS: Volumes of the injured orbits were significantly different from volumes of the uninjured orbits preoperatively (P < .05), whereas bilateral orbital volumes showed no statistically significant difference postoperatively (P > .05). In addition, 19 of the 21 pairs of bilateral distances showed no significant difference postoperatively (P > .05). CONCLUSIONS: Quantitative assessment showed that digitally designed, rapid-prototyping templates for ZMC fractures have a positive impact on restoring facial symmetry and concordance of bilateral orbital volumes.

Treatment of large posttraumatic tibial bone defects using the Ilizarov method: a subjective outcome assessment.

BACKGROUND: The treatment of large posttraumatic tibial bone defects using the Ilizarov method was shown to be successful in several studies. These studies, however, typically focus on the radiological and functional outcome using objective parameters only. The aim of the present study was therefore to assess the objective and subjective outcome of a consecutive series of patients with large posttraumatic tibial bone defects using the Ilizarov method. Additionally, it was our goal to assess the physical and mental stress for the patients and their relatives during the long treatment period and the general health status at final follow-up. METHODS: A consecutive series of 15 patients with posttraumatic tibial bone defects of >30 mm after sustaining open tibial fractures and failure of internal fixation was included. The objective outcome was assessed at final follow-up using Paley's criteria. For the assessment of the subjective outcome, all patients were asked to evaluate their satisfaction with the function of the lower leg, the cosmetic appearance and overall outcome as well. The physical and mental stress of the treatment for the patients and the nearest relative of patients were assessed at the time of frame removal using a custom-made questionnaire. The SF-36 was used to evaluate the general health status at final follow-up. RESULTS: Solid bone union with stable soft tissue coverage and eradication of infection was achieved in all patients despite a high complication rate. The functional outcome at final follow-up was excellent or good in all patients. The patients' satisfaction with the overall outcome and the function of the lower extremity was high as well. The fear of amputation and complications was the major subjective burden for both the patients and their relatives. The long external fixation time is another relevant issue. CONCLUSION: The Ilizarov method is a safe option for the treatment of large posttraumatic tibial bone defects after failure of internal fixation despite the high complication rate. It is essential to comment this to the patients and their relatives prior to the application of the frame increase their compliance with the long and emotionally draining treatment. The Ilizarov method is worth the effort only in patients, who will presumably comply with this treatment option and all of its drawbacks.

A novel external fixator of the hand: a practice pearl.

External fixation of comminuted hand fractures, especially those associated with soft-tissue injuries, is a good option and avoids several complications resulting from open surgery. Therefore, many versions of mini external fixators have been developed, including commercially fabricated implants and hand-made implants. However, these devices are costly or associated with serious complications. Through this study we have introduced a cost-effective and easy-to-apply mini external fixator.

Risk of redisplacement after first successful reduction in paediatric distal radius fractures: sensitivity assessment of casting indices.

The aim of this study was to assess the usefulness of currently available indices for casting in distal radius fractures in children and to identify risk factors associated with displacement. A cohort of 14 patients with redisplacement was compared with a cohort of 41 patients with maintenance of reduction. A significant difference (<0.008) was observed in the three-point index, the degree of comminution (<0.01) and the quality of the initial reduction (<0.003). We recommend careful identification of high-risk factors and appropriate stabilization for potentially unstable fractures at first treatment. Assessment of the three-point index is recommended for judging the moulding technique.

Seven-year retrospective clinical study evaluating efficacy of stainless steel mesh in mandibular fractures.

PURPOSE: The use of titanium mesh in communited mandibular fractures has been substantially documented. However, the use of stainless steel mesh for routine fixation in mandibular fractures has not been widely reported. The aim of the present study was to evaluate the efficacy of stainless steel mesh for routine osteosynthesis of mandibular fractures. MATERIALS AND METHODS: A total of 252 patients who had been diagnosed with 287 single or multiple mandibular fractures at Guru Nanak Institute of Dental Science and Research from 2002 to 2009 were selected for the present study. Those with condylar fractures and other maxillofacial injuries were excluded from the study. The patients were evaluated preoperatively, intraoperatively, and postoperatively at 1 day, 6 weeks, and 3 and 6 months. The local complications, occlusion (for static function), and chewing (for dynamic function) were evaluated postoperatively. RESULTS: The intraoperative time taken for implant fixation (from site exposure to fixation of the last screw) was 32 minutes. Of the 252 patients, 40 (15.8%) had local complications and 24 patients required implant removal. Of the 252 patients, 82% had bilaterally satisfactory occlusion according to the surgeon at 6 months postoperatively. Discomfort in chewing unilaterally or bilaterally was reported by 17% of the patients. CONCLUSION: The results of our study have shown that stainless steel mesh has acceptable complication rates and the ability to maintain occlusion and chewing postoperatively compared with the present standards of care of mandibular fractures using miniplates. The lower cost and versatile placement of screws were the principal advantages. However, placement near the mental foramen with an extraoral approach for certain sites is the primary disadvantage.

Incidence, management, and prognosis of early ulnar nerve dysfunction in type C fractures of distal humerus.

BACKGROUND: Displaced comminuted of the distal humerus in adults are among the most complex fractures to be managed effectively. The ulnar nerve is at high risk of impingement secondary to injury, operation, and postoperative rehabilitation in these fractures. In this study we focus on the incidence, management, and prognosis of early ulnar nerve dysfunction in the course of treating type C fractures of distal humerus. METHODS: We examine a patient sample of 117 consecutive AO type C fractures of distal humerus, between June 1998 and October 2005. Twenty-nine patients exhibited preoperative ulnar nerve compression symptoms (incidence 24.8%) and were divided into two groups randomly, which received treatment of anterior subfascial transposition or in situ decompression of the ulnar nerve respectively, in conjunction with internal fixation with medial and lateral plates. RESULTS: The subgroup of 88 patients without preoperative ulnar nerve symptoms remained asymptomatic postoperatively (0% incidence of late ulnar nerve dysfunction). According to Bishop rating system, excellent and good results of ulnar nerve function were achieved in 13 of 15 patients (86.7%) in the transposition group, 8 of 14 patients (57.1%) in the in situ decompression group. The results difference is statistically significant (p < 0.05). CONCLUSIONS: We conclude that neurolysis and anterior subfascial transposition of vascularized ulnar nerve during open reduction and internal fixation of type C fractures of the distal humerus is beneficial in cases of early ulnat nerve dysfunction.

Clinical implementation of a multidirectional, angular stable osteosynthesis system in maxillofacial traumatology.

AIM: To investigate whether a multidirectional, angular stable osteosynthesis system is suitable for the treatment of mandibular fractures and to compare it with well established available systems. MATERIAL AND METHODS: Following preliminary testing in an animal model, the multidirectional angular stable system TiFix 2.3 obtained from Litos (Hamburg, Germany) was utilised for internal fixation of 39 mandibular fractures. These involved four symphyseal fractures, 17 parasymphyseal, 16 of the angle of the mandible and two comminuted fractures. The surgical and postoperative course was closely scrutinised. Radiographs were taken after 6 months and all plates removed under local anaesthesia. Photographs were taken intraoperatively and the plates and surrounding soft tissues were salvaged for histological analysis. Additionally, these operations were compared with treatment of equivalent fractures which were treated with conventional, non-angular stable systems. The relative costs have also been evaluated. RESULTS: In 33 of the 39 fractures one TiFix plate sufficed for osteosynthesis. The plate most often used was a 2-hole plate which was applied in 25 (55.5%) fractures, followed by the 4-hole plates used in 16 (35.5%) fractures. In two comminuted fractures, four 6-hole plates were used (9%). In 17 patients the operation lasted less than 30 min, in 20 patients less than 60 min, in two less than 120 min. In all cases, the operations were shorter, and due to the plates' dimensions fewer screws had to be used, thus reducing the costs. DISCUSSION: This angular stable system enabled reduction of the amount of the implant material. Also reduced were the operation time and the cost of the procedure. Furthermore, in the future it will allow smaller access incisions and better preservation of the soft tissue integrity.

Assessment of patients treated for intracapsular fractures of the mandibular condyle by closed techniques.

PURPOSE: The goals to study different lines of intracapsular fractures of the mandibular condyle and to evaluate their influence on the prognosis after closed treatment. PATIENTS AND METHODS: Clinical, radiologic, and axiographic follow-up of 40 patients with 50 intracapsular fractures of the mandibular condyle was carried out after closed treatment. The examinations were performed an average of 22 weeks after treatment. Three types of intracapsular fractures were distinguished: type A, or fractures through the medial condylar pole; type B, or fractures through the lateral condylar pole with loss of vertical height of mandibular ramus, and type M, multiple fragments, comminuted fractures. RESULTS: Moderate to serious dysfunction was observed in 33% of the cases. Radiologic examination of fracture types B and M revealed a reduction in the height of the mandibular ramus of up to 13% compared with the contralateral side. These 2 fracture types also resulted in the most prominent deformations of the condylar head. Axiography revealed irregular excursions and a limitation of condylar movement in comminuted fractures of up to 74% compared with the nonfractured side. CONCLUSION: Lesions to the osseodiscoligamentous complex of the temporomandibular joint caused by intracapsular fractures of the mandibular condyle can be severe. The poor functional and radiologic results encountered in the fracture types B and M showed the limitations of closed functional treatment.

Pilon fractures: assessment and treatment.

The treatment of high-energy intra-articular fractures of the tibial plafond involves many potential complications. A protocol has been developed. This protocol recognizes the importance of the surrounding soft tissues and is based on sound principles and thorough clinical experience. This article discusses this protocol and its use and explains why it is now more widely accepted.

Open reduction and internal fixation in 46 displaced intraarticular calcaneal fractures.

The subject of this report is the evaluation of 46 comminuted displaced intraarticular calcaneal fractures in 40 patients treated by open reduction and internal fixation. The results were validated by a score based on objective findings and a subjective gradation obtained by a visual analyzing score (VAS). The results were excellent or good in 30 treated fractures, while the results in 9 fractures were validated a satisfactory and in 7 as unsatisfactory. The results concerning disability and need for workman's compensation were promising in patients who had suffered fractures known to result in a high disability and compensation rate.

Stereolithography: a historical review and indications for use in the management of trauma.

BACKGROUND: Stereolithography (SL) is a new adjunct for treatment planning in complex maxillofacial trauma. It uses an argon/ion laser to polymerize acrylic resin models of reformatted computerized tomographic radiographs. SL provides superior anatomical detail and translucency, and it can be sterilized and transported to the operative field, if necessary. DISCUSSION: A review of the historical development of SL technology is presented, along with three clinical cases, showing the advantages of SL models in the treatment of patients with complex maxillofacial trauma. CONCLUSION: SL technology provides superior understanding of anatomic relationships, the ability to perform presurgical simulation of the proposed procedure, preoperative adaptation of biomaterials, decreased time in the operating room and associated patient morbidity, and improved residency training and patient education. The primary disadvantages of SL are availability and cost.