Comminuted olecranon fractures: biomechanical testing of locked versus minifragment non-locked plate fixation.

INTRODUCTION: Open reduction and internal fixation has long been accepted as optimal treatment for displaced olecranon fractures based on poor results seen with conservative management. With the presence of comminution, tension-band wiring constructs are contraindicated due to tendency to compress through fragments, thereby shortening the articular segment. Therefore, plate fixation is typically employed. Our hypothesis was that in a comminuted fracture model, 2.7 mm reconstruction plating without locking screws will perform equally to 3.5 mm locked plating in terms of fracture displacement and rotation (shear). MATERIALS AND METHODS: A three-part comminuted olecranon fracture pattern was created in nine matched pairs of cadaveric specimen using an oscillating saw in standardized, reproducible fashion. Each matched pair was then randomized to receive either 2.7 mm reconstruction plating or 3.5 mm proximal ulna locked plating. Random allocation software was used to assign the 2.7 mm plate construct to either the right or left side of each pair with the contralateral receiving the 3.5 mm plate construct. Specimens were cyclically loaded simulating passive range of motion exercises commonly performed during rehabilitation. Displacement and rotation in relation to the long axis of the ulna were measured through motion capture. Fragment gapping and rotation was quantified following 100 cycles at 10 N and again following 100 cycles at 500 N. RESULTS: No significant differences were detected between the 2.7 and 3.5 mm plates in fracture rotation or gapping following loads at 10 N (0.5° and 0.7°; 0.6 and 1.2 mm; respectively; p > 0.05) or 500 N (2.3° and 1.6°; 3.8 and 3.1 mm; respectively; p > 0.05) loading. Fragment rotation and gapping were positively correlated within each plate construct (R 2 > 0.445; p < 0.05). CONCLUSIONS: 2.7 mm plating is an alternative to 3.5 mm locked plating with decreased plate prominence without significantly sacrificing displacement and rotational control. This is beneficial in fracture patterns where the traditional dorsal plating does not offer optimal screw trajectory.

Quantitative assessment of patellar vascularity following bone-patellar tendon-bone autograft harvest for ACL reconstruction.

PURPOSE: Recent anatomic studies have suggested that the dominant arterial supply of the patella enters through the inferior pole. Based upon these findings, we hypothesized that bone-patellar tendon-bone graft harvest can significantly diminish patellar vascularity. METHODS: Nine matched pair cadaveric knee specimens (mean age 47.4 years) were dissected and cannulated. A single knee was selected to undergo routine graft harvest, and the contralateral knee was left intact to serve as a control. Gadolinium was injected, and magnetic resonance imaging (MRI) signal enhancement was quantified to determine differences in uptake. Each matched pair was subsequently injected with a urethane polymer compound and dissected to correlate vessel disruption with MRI findings. RESULTS: We identified two predominating patterns of vessel entry. In one pattern, the vessel entered the inferomedial aspect (five o'clock/right, seven o'clock/left) of the patella and was disrupted by graft harvest in 2/9 (22.2 %) pairs. In the second pattern, the vessel entered further medial (four o'clock/right, eight o'clock/left) and was not disrupted (7/9, 78.8 %). The mean decrease in gadolinium uptake following disruption of the predominant vessel measured 56.2 % (range 42.6-69.5 %) compared to an average decrease of 18.3 % (range 7.1-29.1 %) when the dominant arterial supply to the inferior pole remained intact (p < 0.04). CONCLUSION: Medial entry of the predominant vessel precluded vessel disruption. Disruption of the dominant arterial supply can result in a significant decrease in patellar vascularity. Modification of graft harvest techniques and areas of surgical dissection should be explored to minimize vascular insult. Further correlation with clinical studies/outcomes is necessary to determine a potential association between vascular insult and anterior knee pain.

Outcomes of Proximal Humerus Fracture Open Reduction Internal Fixation with Concomitant Ipsilateral Shoulder Girdle Injuries: a Case Control Study.

BACKGROUND: Proximal humerus fractures treated in the face of ipsilateral injuries to the shoulder girdle may be predisposed to worse clinical outcomes. QUESTIONS/PURPOSES: The purpose of this investigation was to examine outcomes of proximal humerus fractures treated with open reduction internal fixation (ORIF) using an endosteal augment in the presence of a concomitant shoulder girdle injury in comparison to isolated proximal humerus fractures treated with ORIF and endosteal augment. METHODS: A prospective database was used to identify proximal humerus fractures with ipsilateral shoulder girdle injuries (glenohumeral and acromioclavicular dislocation, fractures of the acromion, clavicle, scapula, or humeral diaphysis). These were compared to isolated proximal humerus fractures treated in the same fashion (ORIF with endosteal augment). Minimum of 1 year follow-up was required for inclusion. Outcomes assessed included range of motion (ROM), development of avascular necrosis (AVN), hardware-related complications, reoperation, and subjective outcome assessments including the Disabilities of Arm Shoulder and Hand questionnaire (DASH), Constant score, UCLA rating scale, and the Short Form-36 (SF-36). RESULTS: Fifteen ipsilateral injuries were seen in 14 patients. Seventy-seven isolated proximal humerus fractures were available for comparison. The ipsilateral injury group had significantly worse forward flexion (141 vs 156°, p = 0.02), external rotation (56 vs 64°, p = 0.03), higher rates of avascular necrosis (4 of 14, 28.6% vs 1 of 77, 1.3%, p = 0.002), and inferior SF-36 physical health scores (48.5 vs 63.5; p = .04). Despite these differences, no significant differences were seen with hardware-related complications or DASH, Constant score, or UCLA rating scale results. No patients required secondary reconstructive procedures. CONCLUSION: Despite a statistically higher rate of AVN and decreased ROM, patient-based outcomes of proximal humerus fractures with ipsilateral shoulder injuries approached those seen in isolated proximal humerus fractures. This suggests that these injuries can achieve similarly good clinical results provided any associated shoulder pathology is identified and treated appropriately.

Intramedullary allograft fibula as a reduction and fixation tool for treatment of complex proximal humerus fractures with diaphyseal extension.

SUMMARY: In this study, we present a novel technique for reduction and fixation of complex, unstable proximal humerus fractures with diaphyseal extension with the assistance of fibula allograft. We treated 14 patients using this technique since 2009 and found that it improves the reduction and enhances fixation while making the surgical procedure technically more manageable, and allows for early postoperative motion. In the first part of this study, we describe in detail the indications and surgical technique applied to these fractures. In the second part, we review the clinical and radiographic outcomes of these patients. Using this new technique, we have achieved an excellent union rate with minimal incidence of complications when treating these challenging fractures.

Outcomes of Schatzker II tibial plateau fracture open reduction internal fixation using structural bone allograft.

OBJECTIVES: The purpose of this study is to report the rate of anatomic reduction, articular subsidence, and clinical outcomes for Schatzker II tibial plateau fractures treated with structural bone allografts. DESIGN: This is a retrospective case series. SETTING: Academic Level I Trauma Center. PATIENTS/PARTICIPANTS: A trauma registry was used to identify 77 Schatzker II tibial plateau fractures. INTERVENTION: Schatzker II tibial plateau fracture open reduction internal fixation and structural bone graft using either Plexur P (N = 29) or fibular allograft (N = 48). MAIN OUTCOME MEASUREMENT: The primary outcome was articular subsidence. Secondary outcomes included fracture malreduction and clinical outcomes including the Knee Outcome Survey Activities of Daily Living Scale, the Lower Extremity Functional Scale, and the Short Form (SF)-36. RESULTS: No patients experienced subsidence > 2mm. This rate is significantly lower than published rates for autogenous iliac crest (30.3%, P < 0.0001) and calcium phosphate cement (8.7%, P = 0.0099). The rate of fracture malreduction was 11.7% (9/77); only 4 had more than 3 mm of residual incongruity. Average outcome scores were the following: Knee Outcome Survey Activities of Daily Living Scale, 81.7; Lower Extremity Functional Scale, 78.5; SF-36 physical component, 48.3; and SF-36 mental component, 53.1. There was no difference between patients treated with Plexur P or fibula with regard to the primary or secondary outcomes. CONCLUSIONS: The use of structural allograft resulted in a high rate of anatomic reduction and negligible rate of articular subsidence and good clinical outcomes in the treatment of this population of Schatzker II tibial plateau fractures. This compares favorably with historical results using nonstructural grafts. LEVEL OF EVIDENCE: Therapeutic level IV. See instructions for authors for a complete description of levels of evidence.

The impact of preoperative coronal plane deformity on proximal humerus fixation with endosteal augmentation.

OBJECTIVES: To examine the impact of preoperative coronal plane deformity on functional and radiographic outcomes on endosteal strut augmentation of proximal humerus fracture fixation. DESIGN: Single surgeon, retrospective analysis of a prospective database. Case series. SETTING: Academic level 1 trauma center. PATIENTS/PARTICIPANTS: Seventy-two patients with isolated proximal humerus fractures fulfilled all inclusion/exclusion criteria with a minimum follow-up of 12 months. INTERVENTION: Proximal humerus open reduction internal fixation with a laterally placed proximal humeral locking plate and endosteal placement of an allograft fibula treated through the anterolateral approach. MAIN OUTCOME MEASUREMENTS: Global functional outcome as determined by the Disabilities of the Arm, Shoulder and Hand (DASH) score and Short Form 36 physical function. Shoulder-specific functional outcome as determined by the Constant-Murley and the University of California Los Angeles shoulder scores. RESULTS: The mean age was 62 years old (range, 26-90 years). There were 32 varus fractures (neck-shaft angle, 110.8 degrees) and 40 valgus fractures (neck-shaft angle, 168.9 degrees). There was no significant difference in the initial postoperative (varus: 132.5 degrees, valgus: 135.5 degrees) and final (varus: 129.9 degrees, valgus: 132.2 degrees) neck-shaft angles or change in humeral height (varus: 0.94 mm, valgus: 1.48 mm). There were no significant differences in functional outcomes [Constant (varus: 85.2, valgus: 88.7) DASH (varus: 21.4, valgus: 13.9), University of California Los Angeles (28.6, varus 30.4), and Short Form 36 (varus: 66.8, valgus: 59.1)]. There were 2 patients in the valgus group and 3 patients in the varus group with an asymptomatic humeral head screw penetration (mean Constant 84.5, DASH 9.5). There was 1 deep infection in the varus group and 2 in the valgus group necessitating implant removal after fracture union. There was 1 case of avascular necrosis in the valgus group (DASH 19.4, Constant 73). CONCLUSIONS: There were no significant differences in complication rates, radiographic, or clinical outcomes between fractures presenting with preoperative varus coronal displacement compared with those presenting with valgus coronal displacement. The equivalent outcomes may be attributed to the uniform operative technique and fibular strut augmentation used by the primary surgeon. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Articular congruity is associated with short-term clinical outcomes of operatively treated SER IV ankle fractures.

BACKGROUND: With regard to supination-external rotation type-IV (SER IV) ankle fractures, there is no consensus regarding which patient, injury, and treatment variables most strongly influence clinical outcome. The purpose of this investigation was to examine the impact of articular surface congruity on the functional outcomes of operatively treatment of SER IV ankle fractures. METHODS: A prospectively generated database consisting of operatively treated SER IV ankle fractures was reviewed. Postoperative computed tomography (CT) scans were used to assess ankle joint congruity. Ankles were considered incongruent in the presence of >2 mm of articular step-off, intra-articular loose bodies, or an articular surface gap of >2 mm (despite an otherwise anatomic reduction) due to joint impaction and comminution. Patients with at least one year of clinical follow-up were eligible for analysis. The primary and secondary outcome measures were the Foot and Ankle Outcome Score (FAOS) and ankle motion. RESULTS: One hundred and eight SER IV fractures met our inclusion criteria. The average duration of follow-up was twenty-one months. Seventy-two patients (67%) had a congruent ankle joint, and thirty-six (33%) had elements of articular surface incongruity on postoperative CT scanning. These two groups were similar with regard to comorbidities and injury and treatment variables. At the time of the final follow-up, the group with articular incongruity had a significantly worse FAOS with regard to symptoms (p = 0.012), pain (p = 0.004), and activities of daily living (p = 0.038). Those with articular incongruity had worse average scores in the FAOS sport domain as well. No significant differences in ankle motion were found between the two groups. CONCLUSIONS: In this population of patients with an operatively treated SER IV ankle fracture, the presence of postoperative articular incongruity correlated with inferior early clinical outcomes. Orthopaedic surgeons should scrutinize ankle fracture reductions and strive for perfection to allow for the best possible clinical outcome. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Defining the lateral and accessory views of the patella: an anatomic and radiographic study with implications for fracture treatment.

OBJECTIVE: The majority of orthopaedic surgeons rely on a lateral fluoroscopic image to assess reduction during patella fracture osteosynthesis. However, a comprehensive radiographic description of the lateral view of the patella has not been performed previously, and no accessory views to better visualize specific anatomic features have been developed. The purpose of this study was to provide a detailed anatomic description of all radiographic features of the true lateral of the patella, describe reproducible accessory views for assessing specific features of the patella, and demonstrate their utility in a fracture model. METHODS: Twelve cadaver knee specimens free of patellofemoral pathology were used, and imaging was performed using standard C-arm fluoroscopy. For each specimen, a true lateral radiographic projection of the patella was obtained and distinct features were noted. Next, an arthrotomy was made and steel wire was contoured and fixed to various anatomic regions of the patella so as to obliterate the radiographic densities on the true lateral projection, thus confirming their anatomic correlation. Ideal views of the lateral and medial facets themselves were determined using radiographic markers and varying amounts of internal or external rotation of the specimen. Last, a transverse osteotomy was created in each patella and the ability of the true lateral and accessory views to detect malreduction was assessed. RESULTS: The true lateral projection of the patella was obtained with the limb in neutral alignment. Constant radiographic features of the lateral view of the patella include the articular tangent, a secondary articular density of variable length, and a dorsal cortical density. The articular tangent was produced by the central ridge between the medial and lateral facets in all specimens. The secondary articular density was created by a confluence of the edge of the lateral and edge of the medial facets in 5 patellas, a confluence of the edge of the lateral facet and the intersection of the odd and medial facets in 6 patellas, and the edge of the lateral facet alone in 1 patella. The edge of the lateral facet gave a constant contribution to the appearance of the secondary articular density in all cases. A distinct accessory view of the tangent of the lateral facet could be seen with an average of 17 degrees of patella external rotation (range, 12-35 degrees), and the tangent of the medial facet with an average of 26.5 degrees of internal rotation (range, 15-45 degrees). These accessory views were better able to visualize malreduction than the single lateral projection in a fracture model in all specimens. CONCLUSIONS: Described here is a comprehensive description of the true lateral radiographic view of the patella and accessory views. These views can be used in the evaluation of minimally displaced patella fractures if a computerized tomography is not desired to better assess the true amount of displacement and when assessing intraoperative reduction during patella fracture osteosynthesis.

Outcomes after operative fixation of complete articular patellar fractures: assessment of functional impairment.

BACKGROUND: Patellar fractures are debilitating injuries that compromise the knee extensor mechanism and are frequently associated with poor outcomes. The purpose of this study was to quantify the functional outcomes of operative treatment of patellar fractures. METHODS: Functional outcome data on thirty patients with an isolated unilateral patellar fracture were prospectively obtained at three, six, and twelve months postoperatively. RESULTS: All fractures healed. There were two complications (7%) related to the surgery (wound dehiscence and refracture), and eleven patients (37%) underwent removal of symptomatic implants. The tibial plateau-patella angle demonstrated patella baja in seventeen (57%) of the patients. Anterior knee pain during activities of daily living was experienced by twenty-four (80%) of the patients. Clinical improvement occurred over the first six months. However, functional impairment persisted at twelve months, with objective testing demonstrating that the knee extensor mechanism on the injured side had deficits in strength (-41%), power (-47%), and endurance (-34%) as compared with the uninjured side. CONCLUSIONS: Despite advances in surgical protocols and acceptable radiographic outcomes, functional impairment remains common after treatment of patellar fractures. Rehabilitation strategies following surgical stabilization of these injuries will be a fruitful area for future clinical research.

Assessment of femoral head and head-neck junction perfusion following surgical hip dislocation using gadolinium-enhanced magnetic resonance imaging: a cadaveric study.

BACKGROUND: The purpose of the present study was to quantify perfusion to the femoral head and head-neck junction using gadolinium-enhanced magnetic resonance imaging following three surgical dislocations of the hip (trochanteric flip osteotomy, standard posterior approach, and modified posterior approach). METHODS: The medial femoral circumflex artery was cannulated in fifty fresh-frozen cadaveric hips (twenty-five pelvic specimens). One hip on each pelvic specimen was randomly chosen to undergo one of the three surgical dislocations, and the contralateral hip was used as a control. Gadolinium enhancement on the magnetic resonance imaging scan was quantified in both the femoral head and head-neck junction by volumetric analysis using custom magnetic resonance imaging analysis software. A polyurethane compound was then injected, and gross dissection was performed to assess the extraosseous vasculature. RESULTS: Magnetic resonance imaging quantification revealed that the trochanteric flip osteotomy group maintained almost full perfusion (mean, 96% for the femoral head and 98% for the head-neck junction). The standard posterior approach almost completely compromised perfusion (mean, 4% for the femoral head and 8% for the head-neck junction). Six specimens in the modified posterior approach group demonstrated partial perfusion (mean, 32% in the femoral head and 26% in the head-neck junction). Three specimens in the modified posterior approach group demonstrated almost full perfusion (mean, 96% in the femoral head and 97% in the head-neck junction). Gross dissection revealed that all specimens in the standard posterior approach group and seven of ten in the modified posterior approach group sustained disruption of the ascending branch of the medial femoral circumflex artery. All specimens in the standard posterior approach group demonstrated disruption of the inferior retinacular artery. The inferior retinacular artery remained intact in nine of ten specimens in the modified posterior approach group. One specimen in the modified posterior approach group that had disruption of both the ascending medial femoral circumflex artery and inferior retinacular artery demonstrated a substantial decrease in perfusion (7% in the femoral head and 5% in the head-neck junction). CONCLUSIONS: The trochanteric flip osteotomy preserves the vascular supply to the femoral head and head-neck junction. The standard posterior approach disrupts the vascular supply and should be completely abandoned for surgical hip dislocation. Despite reduced enhancement, substantial perfusion of the femoral head and head-neck junction was present in the modified posterior approach group, likely because of the preservation of the inferior retinacular artery. The modified posterior approach produced variable results, indicating that improvement to the modified posterior approach is needed. CLINICAL RELEVANCE: Our study provides previously unreported quantitative magnetic resonance imaging data on the perfusion to the femoral head and head-neck junction during common surgical approaches to the hip.

Effect of computerized tomography on classification and treatment plan for patellar fractures.

OBJECTIVE: To evaluate the impact of computerized tomography (CT) scan on both fracture classification and surgical planning of patellar fractures. DESIGN: Prospective study. SETTING: Academic level I trauma center. PATIENTS AND METHODS: Four fellowship-trained orthopaedic trauma surgeons analyzed radiographs of 41 patellar fractures. Each fracture was classified (OTA/AO classification), and a treatment plan was developed using plain radiographs alone. The process was repeated (4-6 weeks later) with addition of CT scan. After 12 months, the 2-step analysis was repeated and interobserver reliability and intraobserver reproducibility were assessed. RESULTS: Suboptimal intra- and interobserver reliability was found for the surgical plan and classification using the OTA/AO system, despite the addition of a CT scan. After addition of CT, reviewers modified the classification in 66% of cases and treatment plan in 49%. CT frequently demonstrated a distinctive and severely comminuted distal pole fracture; this fracture pattern was present in 88% of cases and was unappreciated on plain radiographs in 44% of those cases. This pattern is unaccounted for by the present OTA/AO classification. CONCLUSIONS: CT facilitates improved delineation of patellar fracture patterns. Understanding the distal pole fracture pattern is fundamental in choosing a fixation construct. A fracture-specific classification system, based on CT scans, should be developed.

Quantitative and qualitative assessment of bone perfusion and arterial contributions in a patellar fracture model using gadolinium-enhanced magnetic resonance imaging: a cadaveric study.

BACKGROUND: The purpose of the present study was to evaluate the anatomy and contribution of the patellar vascular supply and to quantify the effect of a transverse fracture on patellar perfusion. METHODS: In twenty matched pairs of fresh-frozen cadaveric knees, the superficial femoral artery, anterior tibialis artery, and posterior tibialis artery were cannulated. One side of each matched pair was randomly selected to undergo one of two osteotomies: (1) midpatellar osteotomy or (2) distal-pole osteotomy. For volumetric analysis, comparisons were performed between contrast-enhanced magnetic resonance images and precontrast magnetic resonance images as well as between osteotomized patellar bone fragments and the corresponding intact areas on the control side. We then injected a urethane polymer compound and dissected all specimens to examine extraosseous vascularity. RESULTS: Magnetic resonance imaging demonstrated that the largest arterial contribution to the patella entered at the inferior pole in 100% of the specimens; in 80% of these specimens, the artery entered inferomedially. It also revealed an overall decrease in contrast enhancement in both transverse osteotomy groups, with an average reduction in enhancement in the proximal fragment of 36%. CONCLUSIONS: If possible, surgical interventions about the knee should be carefully planned to preserve the peripatellar ring (the source of the entire patellar blood supply), especially the inferior patellar network. Distal-pole patellectomy should be avoided to retain vascularized bone at the reduced fracture site.