Comparison of modern locked plating and antiglide plating for fixation of osteoporotic distal fibular fractures.

BACKGROUND: Fractures in osteoporotic patients can be difficult to treat because of poor bone quality and inability to gain screw purchase. The purpose of this study is to compare modern lateral periarticular distal fibula locked plating to antiglide plating in the setting of an osteoporotic, unstable distal fibula fracture. METHODS: AO/OTA 44-B2 distal fibula fractures were created in sixteen paired fresh frozen cadaveric ankles and fixed with a lateral locking plate and an independent lag screw or an antiglide plate with a lag screw through the plate. The specimens underwent stiffness, cyclic loading, and load to failure testing. The energy absorbed until failure, torque to failure, construct stiffness, angle at failure, and energy at failure was recorded. RESULTS: The lateral locking construct had a higher torque to failure (p=0.02) and construct stiffness (p=0.04). The locking construct showed a trend toward increased angle at failure, but did not reach statistical significance (p=0.07). Seven of the eight lateral locking plate specimens failed through the distal locking screws, while the antiglide plating construct failed with pullout of the distal screws and displacement of the fracture in six of the eight specimens. CONCLUSION: In our study, the newly designed distal fibula periarticular locking plate with increased distal fixation is biomechanically stronger than a non-locking one third tubular plate applied in antiglide fashion for the treatment of AO/OTA 44-B2 osteoporotic distal fibula fractures. LEVEL OF EVIDENCE: V: This is an ex-vivo study performed on cadavers and is not a study performed on live patients. Therefore, this is considered Level V evidence.

Treatment of Acute Jones Fractures Without Weightbearing Restriction.

Jones fractures are reportedly prone to nonunion and generally treated with a period of non-weightbearing or operative treatment. Extended non-weightbearing can have adverse effects, and operative treatment poses various risks. We report the clinical results of patients treated without weightbearing restriction. All patients treated for metatarsal fractures by a single surgeon from January 1, 2000 to December 31, 2009 were identified through the clinical billing records by International Classification of Diseases, ninth revision, code. Through a radiographic and medical record review, 27 consecutive patients with acute Jones fractures treated without weightbearing restriction were identified. The demographic information and clinical and radiographic results were recorded. Of the 27 patients, 24 (89%) had achieved clinical union at a mean of 8.0 ± 2.6 weeks. Complete radiographic union was noted in 13 (48%) patients, and 13 (48%) others had made significant progress toward radiographic union but had not yet reached it. Two (8.3%) patients were lost to follow-up. One patient (4%) developed nonunion. Patients with acute Jones fractures can be treated without weightbearing restriction. This protocol results in rapid clinical union and a low rate of nonunion.

Surgeon preferences regarding antibiotic prophylaxis for ballistic fractures.

BACKGROUND: Scant evidence exists to support antibiotic use for low velocity ballistic fractures (LVBF). We therefore sought to define current practice patterns. We hypothesized that most surgeons prescribe antibiotics for LVBF, prescribing is not driven by institutional protocols, and that decisions are based on protocols utilized for blunt trauma. MATERIALS AND METHODS: A web-based questionnaire was emailed to the membership of the Orthopaedic Trauma Association (OTA). The questionnaire included demographic information and questions about LVBF treatment practices. Two hundred and twenty surgeons responded. One hundred and fifty-four (70 %) respondents worked at a Level-1 trauma center, 176 (80 %) had received fellowship education in orthopaedic trauma and 104 (47 %) treated at least 10 ballistic fractures annually. Responses were analyzed with SAS 9.3 for Windows (SAS Institute Inc, Cary, NC). RESULTS: One hundred eighty-six respondents (86 %) routinely provide antibiotics for LVBF. Those who did not were more apt to do so for intra-articular fractures (8/16, 50 %) and pelvic fractures with visceral injury (10/16, 63 %). Most surgeons (167, 76 %) do not believe the Gustilo-Anderson classification applies to ballistic fractures, and (20/29, 70 %) do not base their antibiotic choice on the classification system. Few institutions (58, 26 %) have protocols guiding antibiotic use for LVBF. CONCLUSIONS: Routine antibiotic use for LVBF is common; however, practice is not dictated by institutional protocol. Although antibiotic use generally follows current blunt trauma guidelines, surgeons do not base their treatment decisions the Gustilo-Anderson classification. Given the high rate of antibiotic use for LVBF, further study should focus on providing evidence-based treatment guidelines.

Gel scaffolds of BMP-2-binding peptide amphiphile nanofibers for spinal arthrodesis.

Peptide amphiphile (PA) nanofibers formed by self-assembly can be customized for specific applications in regenerative medicine through the use of molecules that display bioactive signals on their surfaces. Here, the use of PA nanofibers with binding affinity for the bone promoting growth factor BMP-2 to create a gel scaffold for osteogenesis is reported. With the objective of reducing the amount of BMP-2 used clinically for successful arthrodesis in the spine, amounts of growth factor incorporated in the scaffolds that are 10 to 100 times lower than that those used clinically in collagen scaffolds are used. The efficacy of the bioactive PA system to promote BMP-2-induced osteogenesis in vivo is investigated in a rat posterolateral lumbar intertransverse spinal fusion model. PA nanofiber gels displaying BMP-2-binding segments exhibit superior spinal fusion rates relative to controls, effectively decreasing the required therapeutic dose of BMP-2 by 10-fold. Interestingly, a 42% fusion rate is observed for gels containing the bioactive nanofibers without the use of exogenous BMP-2, suggesting the ability of the nanofiber to recruit endogenous growth factor. Results obtained here demonstrate that bioactive biomaterials with capacity to bind specific growth factors by design are great targets for regenerative medicine.

Clinical and radiographic comparisons of two different radial head implant designs.

BACKGROUND: There is little comparative data to guide implant choice for radial head replacements. The purpose of this study was to evaluate the clinical and radiographic results between patients who received a smooth-stemmed bipolar radial head implant and patients who received an in-growth monopolar prosthesis. METHODS: Twenty-seven patients requiring a metallic radial head implant in the management of acute or chronic elbow trauma were evaluated. Fourteen patients received a smooth-stemmed bipolar prosthesis and 13 patients received a press-fit monopolar prosthesis. Patients returned for follow-up at an average of 33 months (range, 18-57). Outcome assessments included joint motion, elbow stability, grip strength, pain, the Mayo Elbow Performance Index, and the Disability of Arm, Shoulder and Hand questionnaire. Radiographs were reviewed for joint congruence, ectopic bone, periprosthetic osteolysis, degenerative arthritis, and capitellar wear, and selected patients were tested for inflammatory markers and metal ion levels. RESULTS: The differences between patient groups for elbow flexion and forearm pronation averaged 10° or less. There were no other pertinent differences between groups for standardized patient and examiner-determined outcomes. There was a trend for ectopic bone to develop more commonly around the smooth-stemmed implants, while periprosthetic osteolysis was more pronounced in cases with the press-fit design. Inflammatory markers were normal, and metal ion levels did not exceed values reported for a well-functioning hip arthroplasty. CONCLUSION: Outcomes at short- to mid-term follow-up were similar with either implant design. Loosening of a press-fit prosthesis may lead to extensive osteolysis, but of undetermined clinical consequence.

Extra-articular distal tibia fractures: a mechanical evaluation of 4 different treatment methods.

OBJECTIVE: This cadaveric biomechanical study compared the mechanical properties of standard plating (SP), locked plating (LP), intramedullary nailing (IMN), and angular stable intramedullary nailing (ASN) for the treatment of axially unstable distal tibia metaphyseal fractures (OTA type 43.A3) with an intact fibula. METHODS: A distal tibia metaphyseal fracture was created in 30 fresh frozen cadaveric specimens by performing an osteotomy 30 mm above the plafond. The fibula was left intact. Specimens were divided into 4 groups. Specimens underwent fracture fixation with a standard distal tibia plate, a medial locked plate, an intramedullary nail, or an angular stable intramedullary nail. Specimens were loaded vertically along the tibial axis to 700 N, followed by cyclical loading at 700 N for 10,000 cycles, and then to failure. RESULTS: The IMN group demonstrated greater stiffness and load to failure than the LP group, which was greater than the SP group. The ASN group was not different in terms of stiffness and load to failure from the LP group for the number of specimens tested. The IM group required the greatest energy to failure, and all groups were significantly greater than the SP group. CONCLUSIONS: Under axial loading conditions with an intact fibula, both IMN and LP provide stable fixation. There was no advantage to the use of an ASN over a standard IMN. IMN resulted in the highest stiffness, load to failure, and failure energy for OTA type 43.A3 fractures with as little as 3 cm of distal bone stock.

Intra-articular distal femur fracture extending from an expanded femoral tunnel in an anterior cruciate ligament (ACL) reconstructed knee: a case report.

Anterior cruciate ligament (ACL) reconstruction is a popular surgery with overall good results. However, postoperative fracture is a serious, albeit, rare complication. Femoral tunnel lysis may cause a stress riser effect leading to distal femur fractures after ACL reconstruction. We report a case in which a patient who underwent ACL reconstruction surgery 18 months before a low-energy twisting mechanism suffered a distal femur fracture requiring open reduction internal fixation.

Scapulothoracic dissociation with acromioclavicular separation: a case report of a novel fixation method.

We present a case of 39-year-old female with a scapulothoracic dissociation and acromioclavicular (AC) separation and who had fixation of the AC joint with a locking plate, coracoclavicular screw, and transarticular AC screw. The coracoclavicular and AC relationships were maintained during postoperative rehabilitation and after hardware removal. Use of a locking plate can lead to good functional outcome without the complications associated with the use of pin and wire constructs or without violating the subacromial space.

Vertically oriented femoral neck fractures: mechanical analysis of four fixation techniques.

OBJECTIVE: Femoral neck fractures in young individuals are typically high angled shear fractures. These injuries are difficult to stabilize due to a strong varus displacement force across the hip with weight bearing. The purpose of this study was to compare the biomechanical stability of four differing fixation techniques for stabilizing vertical shear femoral neck fractures. METHODS: Vertical femoral neck fracture stability was assessed using 4 surgical constructs in 32 cadaveric femurs: 7.3 mm cannulated screws placed in a triangular configuration (group 1), a 135-degree dynamic hip screw (group 2), a 95-degree dynamic condylar screw (group 3), and a locking proximal femoral plate (group 4). The 4 groups were matched for mean bone density and each specimen was tested under incremental loading, cyclical loading, and loading to failure. The modes of fixation failure were recorded for each specimen and the mean group stiffness, failure loads, and failure energies were calculated. RESULTS: All 8 specimens failed during incremental loading in group 1. Five of 8 constructs failed with incremental loading, and 3 failed with cyclical testing in group 2. The combined 16 specimens in groups 3 and 4 survived both incremental and cyclical loading. The differences in stiffness, failure loads, and failure energies between the 4 groups were statistically significant (P < 0.001). The strongest construct was the locking plate and the weakest construct was the 7.3-mm cannulated screw configuration. The cannulated screw configuration group failed as the screws backed out of the femoral head and by varus collapse of the osteotomy; the fixed angled devices all failed at the bone-implant interface. CONCLUSIONS: The strongest construct for stabilizing a vertical shear femoral neck fracture is the proximal femoral locking plate, followed in descending order by the dynamic condylar screw, the dynamic hip screw, and the 3 cannulated screw configuration.

Dislocation of the proximal tibiofibular joint in association with a tibial shaft fracture: two case reports and a literature review.

Dislocation of the proximal tibiofibular joint (PTFJ) in association with a displaced tibial shaft fracture and an intact fibula is an exceedingly rare injury. We present 2 cases of tibia fractures associated with an intact fibula and a PTFJ dislocation. The first case involves a man who sustained a closed spiral fracture of the distal tibial shaft, with an intact fibula, an anterolaterally dislocated PTFJ, and a partial tear of the lateral collateral ligament. The tibia was percutaneously plated, and the PTFJ was reduced and then stabilized with temporary screw fixation. The second case involves a woman who sustained a closed fracture of the tibia in association with a PTFJ dislocation. The tibia was fixed with an intramedullary nail, and the PTFJ was similarly reduced and fixed with a temporary screw. We also provide a brief literature review focusing on classification of PTFJ dislocations, mechanism of injury, associated injuries, and treatment options.

Two-part surgical neck fractures of the proximal part of the humerus. A biomechanical evaluation of two fixation techniques.

BACKGROUND: Successful internal fixation of fractures of the surgical neck of the humerus can be difficult to achieve because of osteopenia of the proximal aspect of the humerus. The purpose of this study was to compare the biomechanical stability of a proximal humeral intramedullary nail and a locking plate for the treatment of a comminuted two-part fracture of the surgical neck in a human cadaver model. METHODS: Twenty-four cadaveric humeri were instrumented with use of either a titanium proximal humeral nail (PHN) or a 3.5-mm locking compression plate for the proximal part of the humerus (LCP-PH). The specimens were matched by bone mineral density and were separated into four experimental groups with six humeri in each: PHN bending, LCP-PH bending, PHN torsion, or LCP-PH torsion. Comminuted fractures of the surgical neck were simulated by excising a 10-mm wedge of bone. Bending specimens were cyclically loaded from 0 to 7.5 Nm of varus bending moment at the fracture site. Torsion specimens were cyclically loaded to +/-2 Nm of axial torque. The mean and maximum displacement in bending, mean and maximum angular rotation in torsion, and stiffness of the bone-implant constructs were compared. RESULTS: In bending, the LCP-PH group demonstrated significantly less mean displacement of the distal fragment than did the PHN group over 5000 cycles (p = 0.002). In torsion, the LCP-PH group demonstrated significantly less mean angular rotation than did the PHN group over 5000 cycles (p = 0.04). A significant number of specimens in the PHN group failed prior to reaching 5000 cycles (p = 0.04). The LCP-PH implant created a significantly stiffer bone-implant construct than did the PHN implant (p = 0.007). CONCLUSIONS: The LCP proximal humeral plate demonstrated superior biomechanical characteristics compared with the proximal humeral nail when tested cyclically in both cantilevered varus bending and torsion. The rate of early failure of the proximal humeral nail could reflect the high moment transmitted to the locking proximal screw-bone interface in this implant. CLINICAL RELEVANCE: The high failure rate in torsion of the proximal humeral nail-bone construct is concerning, and, with relatively osteoporotic bone and early motion, the results could be poor.

Comparison of lateral locking plate and antiglide plate for fixation of distal fibular fractures in osteoporotic bone: a biomechanical study.

OBJECTIVES: The purpose of this study was to compare the biomechanical properties of posterolateral antiglide plating and lateral locked plating for fixation of displaced short oblique fractures of the fibula in osteoporotic bone. METHODS: Short oblique fractures of the distal fibula at the level of the syndesmosis were simulated with a fibular osteotomy and ligamentous sectioning in 18 paired fresh frozen ankles. The fractures were fixed with either a lateral locking plate with an independent lag screw or a posterolateral antiglide plate with a lag screw through the plate. The specimens were tested under a torsional load to failure. The torque to failure, angular rotation at failure, and construct stiffness of the two groups were compared. RESULTS: The torque to failure and construct stiffness were significantly greater on the side with the posterolateral antiglide plate than on the side with the the lateral locking plate (P = 0.01 and 0.005, respectively). CONCLUSIONS: The posterolateral antiglide plate demonstrated improved biomechanical stability as compared to the lateral locking plate in osteoporotic bone. In situations where fixation needs to be optimized, use of an antiglide plate may be favored over a lateral locking plate construct.

Extracapsular placement of distal tibial transfixation wires.

BACKGROUND: Treatment of tibial plafond fractures with external fixation may involve use of transfixation wires within the periarticular region. Pin track infections that develop along wires placed intracapsularly may lead to joint infection. To our knowledge, there have been no previous investigations assessing the circumferential reflection of the ankle capsule or the potential for communication between the distal tibiofibular joint and the tibiotalar joint. The purpose of this study was to define these anatomic entities to provide guidelines for safe extracapsular placement of distal tibial wires. METHODS: Twelve fresh-frozen cadaveric ankles and three ankles of living human volunteers were utilized for this study. High-resolution magnetic resonance imaging was performed on each ankle after pressurized distention of the joint capsule with gadolinium solution. The perpendicular distance from the subchondral bone at the joint line to the capsular synovial reflection was measured with use of a verified technique. The cadaveric ankles were sectioned, the capsular synovial reflections were measured by investigators who were blinded to the imaging results, and the corresponding measurements were compared. RESULTS: The anterolateral capsular synovial region displayed the most proximal reflection in all specimens (mean, 9.3 mm; maximum, 12.2 mm). The anteromedial region displayed less reflection (mean, 3.3 mm; maximum, 5.5 mm). All posteromedial and posterolateral synovial reflections were 12.2 mm from the subchondral surface of the plafond avoids penetration of the capsule. The distal tibiofibular joint communicates with the tibiotalar joint and thus should not be penetrated, to ensure extracapsular placement of the wires.