Lionel E. Lazaro

Catastrophic failure after open reduction internal fixation of femoral neck fractures with a novel locking plate implant.

Objectives: To determine if the use of a novel proximal femoral locking plate could reduce the incidence of femoral neck shortening and improve clinical outcomes after open reduction internal fixation (ORIF) for femoral neck fractures as compared with historical controls. Design: Single surgeon, retrospective case–control study. Setting: Academic level I trauma center. Patients/Participants: Twenty-one femoral neck fractures treated with the posterolateral femoral locking plate (Synthes, Inc, Paoli, PA) were eligible for inclusion. Eighteen met inclusion/exclusion criteria with a mean follow-up of 16 months. Intervention: ORIF of femoral neck fracture with the posterolateral femoral locking plate. This consists of a side plate with multiple locking screws directed into the femoral head at converging/diverging angles and a single shaft screw. Intraoperative compression was achieved with partially threaded screws before locking screw insertion. Main Outcome Measurements: Maintenance of reduction was assessed by comparing immediate postoperative and final follow-up radiographs. Clinical outcome was assessed with Harris Hip Scores after 1 year. Complications and secondary operations were noted. Results: Seven (36.8%) of 18 patients experienced catastrophic failure. Five of these patients required total hip replacement, whereas the remaining 2 died before further treatment. The remaining 11 patients (61.1%) achieved bony union; the average displacement of the center of the head did not differ when compared with historical controls (0.78 mm inferiorly, 1.62 mm medially, and 2.4 degrees of increased varus vs. 0.86 mm, 1.23 mm, and 0.6 degree). Complications in this group include 1 instance of screw fracture, 2 total hip replacements, and a peri-implant subtrochanteric femur fracture. The average patient age and proportion of displaced fractures did not differ between the historical control and experimental groups. Fracture displacement was strongly associated with catastrophic failure in the experimental group only. Average Harris Hip Scores was significantly worse compared with that of historical controls (67.9 vs. 84.7, P = 0.05). Conclusions: ORIF of femoral neck fractures using a locking plate construct yielded unacceptably poor outcomes in this patient population. We hypothesize that the stiffness of this construct prevents any fracture site micromotion, placing the mechanical burden on the implant, which can result in failure at the bone–screw interface or fatigue failure of the implant itself. Level of Evidence: Therapeutic Level III. 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.

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.

Vascular anatomy of the patella: Implications for total knee arthroplasty surgical approaches

BACKGROUND Iatrogenic disruption of the patellar vascular supply has been identified as a possible contributing factor to the commonly reported patellofemoral complications following total knee arthroplasty (TKA). We performed an anatomic cadaveric study evaluating the extra-osseous vascular anatomy of the patella, and correlated our findings to routine TKA surgical dissection to determine how to better preserve patellar vascularity. METHODS AND MATERIALS In twenty-one cadaveric knees arterial cannulas were placed proximally and distally to the patella. A polyurethane compound was then injected producing a visible arterial network. Specimens underwent gross dissection. RESULTS In all 21 specimens, the supreme genicular (SGA), medial/lateral superior genicular (MSGA/LSGA), medial/lateral inferior genicular and anterior tibial recurrent arteries communicate forming a peripatellar anastomotic ring supplying the intraosseous patellar system. Both the SGA (24%) and MSGA (76%) demonstrated dual medial ring contribution. Relating the arterial location to common TKA exposures suggested severe compromise of patellar vascularity. CONCLUSION The medial sided vessels seem to contribute more significantly to the peripatellar anastomotic ring when compared to the lateral sided vessels. Careful soft tissue management has the potential to preserve key vascular structures that could maintain the intraosseous vascular supply to the patella. Understanding the anatomic locations of major arterial systems around the knee joint can potentially help during hemostasis, and can minimize blood loss during TKA. CLINICAL RELEVANCE Recognition of major arterial systems around the knee joint has the potential to minimize iatrogenic disruption of the vascular supply and the complications that can follow (patella devascularization and blood lost).

Complications Following Treatment of Supination External Rotation Ankle Fractures Through the Posterolateral Approach

Background: The posterolateral approach to the ankle is a valuable approach for the treatment of ankle fractures (SER) ankle fractures. The purpose of this study was to determine the complication rate for ankle fractures treated through the posterolateral approach. We hypothesized that this approach would be associated with a low incidence of complications and good clinical outcomes. Methods: A total of 112 patients with SER ankle fractures treated through a posterolateral approach met inclusion criteria. Prospectively collected data were examined retrospectively from chart review, preoperative plain radiographs, and MRI as well as postoperative radiographs. The mean age was 51.5 (range, 18 to 86) years. The primary outcome of the study was major (surgical debridement, flap, or split thickness skin graft) and minor (epidermolysis requiring local wound care) wound complications. The secondary outcomes included infection, symptomatic hardware, reoperation, loss of reduction, malreduction, nonunion, Foot and Ankle Outcome Scores, range of motion, and other perioperative complications. Results: There were 11 minor wound related complications (9.8%) and 3 major wound complications (2.7%), 1 of which required a split thickness skin graft. The overall postoperative wound infection rate was 4.4% (5 of 112); 2 patients required hardware removal due to deep infection. Of patients, 7% (8 of 112) reported symptomatic lateral sided hardware and thus underwent removal of implants. The overall reoperation rate was 12.5%. The complication rate was 23%. No patients experienced loss of reduction. Conclusions: The posterolateral approach to the ankle was a valuable approach for SER ankle fractures. This series demonstrated many key aspects of this approach including access to the apex of the fibula fracture for posterior antiglide plating, access to the posterior malleolus for fixation, access to the posterior inferior tibiofibular ligament for repair, minimal major wound complications, good functional outcomes, and minimal need for reoperation. Level of Evidence: Level IV, retrospective evaluation of prospectively collected data.

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.

Geriatric proximal humeral fracture patients show similar clinical outcomes to non-geriatric patients after osteosynthesis with endosteal fibular strut allograft augmentation

BACKGROUND Osteosynthesis of proximal humeral fractures is challenging in geriatric patients. The purpose of this investigation was to compare postoperative clinical outcomes between cohorts of geriatric (aged ≥65 years) and non-geriatric proximal humeral fracture patients treated via locked plating with endosteal fibular strut allograft augmentation. METHODS From March 2007 to January 2013, 71 adult patients with 2-, 3-, and 4-part proximal humeral fractures according to the Neer classification underwent osteosynthesis with locked plating and fibular allograft augmentation and had at least 12 months of clinical follow-up. All patients followed the same postoperative rehabilitation protocol. We compared the following between geriatric and non-geriatric patients: Disabilities of the Arm, Shoulder and Hand scores; University of California, Los Angeles shoulder ratings; Constant-Murley scores; and range of motion; as well as injury characteristics and radiographic outcomes. RESULTS Geriatric patients comprised 48% of the study cohort (34 of 71 patients). The mean age of the geriatric and non-geriatric cohorts was 74 years and 53 years, respectively. Geriatric patients showed significantly reduced forward flexion (147° vs 159°, P = .04) when compared with non-geriatric patients. There were no significant differences in functional scores, radiographic outcomes, or complication rates between the 2 cohorts, although in 1 geriatric patient, osteonecrosis developed and screw penetration through the collapsed head was present 3 years after surgery. CONCLUSIONS Osteosynthesis of proximal humeral fractures via locked plating with fibular strut allograft augmentation results in similar clinical outcomes between geriatric and non-geriatric patients. We believe that enhanced stability provided by this fixation construct allows early intensive postoperative therapy and results in excellent outcomes despite patient age.

Risk Factors for Posttraumatic Synostosis and Outcomes Following Operative Treatment of Ankle Fractures

Background: Distal tibiofibular synostosis is a known but poorly described complication of ankle fractures. The objective of this study was to evaluate the relationship between ankle fracture fixation method and other risk factors in the development of synostosis in posttraumatic operative ankle fractures. Outcomes of patients with no synostosis, incomplete bony bridging, or complete synostosis also were compared. Methods: All operative ankle fractures from a single surgeon’s prospectively collected clinical database were evaluated for the presence of distal tibiofibular synostosis not earlier than 3 months postoperatively. All fractures were treated in a fracture-specific and ligament-specific fashion. Syndesmotic screws, when used, were routinely removed no sooner than 4 months after operation. Patient demographic and medical history data as well as injury and fixation profile were evaluated. Incidence of complications was also reviewed. Foot and Ankle Outcome Score (FAOS) and range of motion (ROM) were compared between the groups. Results: Of the 564 ankle fractures included in the study, 91 demonstrated complete synostosis and 46 demonstrated incomplete bony bridging. Multivariate analysis revealed male sex (odds ratio [OR] = 2.82, P < .001), syndesmotic screw fixation (OR = 2.46, P < .001), and tibiotalar dislocation (OR = 1.74, P = .032) to remain significant independent risk factors for the development of incomplete bony bridging or complete synostosis while adjusting for confounding risk factors. Ankles with synostosis also demonstrated significant reduction in dorsiflexion (P = .017), plantarflexion (P = .024), and inversion (P < .001), though patient-reported outcome measures were equivalent with patients without synostosis. Conclusion: Syndesmotic screw fixation, male sex, and tibiotalar dislocation were significant risk factors in the formation of postoperative distal tibiofibular synostosis, though patient-reported outcome measures seemed equivalent among patients with and without synostosis. Level of Evidence: Level III, case control study of prospectively collected registry data.

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.

Comparison of Clinical Outcome of Pronation External Rotation versus Supination External Rotation Ankle Fractures

Background: A pronation external rotation (PER) ankle fracture is a relatively uncommon injury. The purpose of this study was to examine the immediate and short-term clinical outcomes of operatively treated PER IV ankle fractures and compare them with a similarly treated cohort of supination external rotation IV (SER IV) fractures. Methods: 22 PER IV and 108 SER IV fractures were identified from a single surgeon’s prospectively collected database from 2004 to 2010. All patients were treated with fracture fragment and ligament specific fixation during the same time period by the same surgeon. Postoperative radiographs and bilateral ankle computed tomography (CT) scans were reviewed for articular incongruity, syndesmotic malreduction, and loss of reduction. Clinical outcome measures, including the Foot and Ankle Outcome Score (FAOS) and ankle range of motion (ROM), were collected at latest follow-up visit. Results: There was no difference in the rate of wound complications, fracture nonunion, or loss of reduction between the PER IV and SER IV groups. There was no significant difference in the incidence of postoperative articular incongruity (19% vs 8%, P = .23); however, the PER IV cohort was found to have a significantly higher rate of syndesmotic malreduction (40% vs 18%, P = .04). No clinically or statistically significant differences were detected between the 2 groups in regard to all FAOS domains. Conclusion: In a cohort of operatively treated PER IV fractures, fracture fragment and ligament specific fixation resulted in good short-term outcomes that were comparable to those seen in similarly treated patients with an SER IV fracture pattern. However, a notably greater number of syndesmotic malreductions were noted in the PER IV cohort, and therefore heightened scrutiny is recommended in treating this particular injury pattern. Level of Evidence: Level III, retrospective comparative study.