Between January 2009 and September 2010, we treated 130 patients with unstable fractures of the proximal part of the femur (31A2, 31A3). The first 72 patients were treated with PFNA; this nail was replaced by PFNA II in our practice for the next 58 cases between February 2010 and September 2010 because we were asked by Synthes (Solothurn, Switzerland) to test the new nail design (PFNA II) regarding the occurrence of lateral cortex impingement, major complications, and fracture healing in unstable fracture types. We excluded 13 patients because of the presence of one or more of the following exclusion criteria: age younger than 60 years, multiple trauma, open injuries, pathological fracture, or a severe medical condition. Another nine patients died or were lost to followup. Of the remaining 108 patients, 58 were treated with PFNA and 50 with PFNA II. Sixty-one were women and 47 were men. The mean age was 78.2 years (range, 60–93 years). The right hip was involved in 59 of the 108 patients. Each fracture was classified using the AO/ASIF classification [25
]. The minimum followup was 12 months (mean, 13 months; range, 12–18 months). No patients were recalled specifically for this study; all data were obtained from medical records and radiographs.
Details of all patients were retrieved from their files, operative reports, and regular followup visits. We recorded demographic data and comorbid medical conditions (Table ) and type of injury (Table ). The two groups had similar demographics and comorbidities (Table ).
Demographics and comorbidities
Fracture and operation variables
Operations were performed by one of three experienced orthopaedic trauma surgeons (GAM, SDK, SAP) familiar with the technique of extra- and intramedullary nailing of the proximal femur. All patients had spinal anesthesia. All operations were performed on a radiolucent traction table where closed reduction of the fracture was carried out under image intensification. When closed reduction failed, a limited open reduction was performed and a retractor was used for the elevation of the distal fragment with particular emphasis on the posteromedial wall reconstruction. In 13 cases, open reduction was necessary, eight in the PFNA group and five in the PFNA II group. A standard operative technique recommended by the manufacturer, as described in detail in instruction manuals, was used. The nail was inserted after a minimal approach proximally to the tip of the greater trochanter without canal reaming except from proximal 17-mm reaming. The blade was inserted without drilling. Distal interlocking was performed in a static manner in all cases. The nails used were 200 mm or 240 mm in length and 10 mm or 11 mm in diameter. Suction drains were not used in either of the PFNA groups. Bone grafting was not used in any of the 108 cases.
All patients received three doses of a prophylactic antibiotic regimen starting 2 hours before the operation. Suction drains were not used in any patients. The length of the operation from skin incision to skin closure and total radiation time were recorded. Criteria for transfusion were constant throughout the study period: hemoglobin value below 8 g/dL or below 10 g/dL in patients with coronary artery disease.
Low-molecular-weight heparin was routinely administered in all patients starting from admission and for a 6-week period. The rehabilitation protocol was uniform regardless of the fracture pattern and the type of fixation. Patients were encouraged to walk with a frame, allowing full weightbearing as tolerated, starting from the first postoperative day when capable. They were all encouraged to perform hip and knee exercises. We recorded time to mobilization, number of units of blood transfused, and length of hospitalization.
All patients were followed up at 1, 3, and 6 months and 1 year with physical examination of the affected limb. Plain AP and lateral radiographs were taken at each visit, incorporated into the patient’s medical file, and reviewed for fracture union or implant failure. We classified walking ability into three categories: able to walk independently without aids or with a stick, walking independently with the help of aids (crutches or frame), and walking only when assisted by another person. Additionally, peri- and postoperative complications, need for transfusion, duration of surgery, fluoroscopy time, time to mobilization, time to discharge, and plain radiography data were all collected and recorded in detail. Potential complications were distinguished as (1) major: cutout, breakage, or migration of the implant, reoperation for any reason, pulmonary embolism, acute coronary infract, acute respiratory distress; and (2) minor, including wound healing disturbances, superficial wound infection, urinary tract infection, and superficial vein thrombosis [13
]. Hip function was estimated with the Harris hip score [16
]. There were no missing data through the followup period.
Plain AP and lateral radiographs were obtained on the first postoperative day and were retrospectively examined by one of us (GAM) specifically for this review for reduction of the fracture and position of the implant. One of us (GAM) evaluated all radiographs for quality of reduction and implant positioning, presence of impingement between the nail and lateral cortex, implant migration, cutout, and presence of callus on AP and lateral radiographs. The reduction was regarded as excellent if it was anatomical, good if it was up to 5° of varus–valgus on the AP view or 5° of ante- or retroversion on the lateral view and up to 5 mm of translation between the main fragments, acceptable if it was up to 10° of varus–valgus on the AP view or 10° of ante- or retroversion on the lateral view, and up to 10 mm of translation between the main fragments and unacceptable beyond those limits. Positioning of the nail into the femoral canal was evaluated, identifying cases in which impingement on the lateral cortex occurred on the AP view. We determined whether the blade was centrally located on both AP and lateral views. Fracture union was determined radiographically as the appearance of a bridging callus on three or four cortices on the AP and lateral views and clinically as a lack of pain sensation around the fracture site [15
The quantitative and qualitative variables are represented by the number of patients (N), mean value (mean), SD, median, interquartile range (IQR), and the frequencies (n) and percentages, respectively. The Kolmogorov-Smirnov test was used for normality analysis of the quantitative data. We determined differences in nail impingement to the lateral cortex, lateral wall fragment, loss of reduction, union, complications related to fixation, and systematic complication using the Fisher’s exact test. The Mann-Whitney test was used to determine differences in the operative time between the two groups. We determined differences in mobility status, quality of reduction, and type using the chi square test. Fisher’s exact test was also used to compare sex, concomitant diseases, and means of reduction. The differences in age, Harris hip score, and blood units transfused were determined using the independent samples t-test. The Mann-Whitney test was also used to compare time to operation, time to mobilization, and hospital stay. The Welch test was used in case of violation of equal variances (fluoroscopy time). All tests were two-tailed. All analyses were carried out using the statistical package SPSS Version 16 (Statistical Package for the Social Sciences, SPSS Inc, Chicago, IL, USA).