Cutting-out of the lag screw after internal fixation with the Asiatic gamma nail

Offset nail fixation for intertrochanteric fractures improves reduction and lag screw position

Background

Surgery for intertrochanteric fractures using intramedullary hip nails (IHNs) is among the most common surgical procedures in the orthopedic field. Although IHNs provide good overall outcomes, they sometimes cause complications, such as loss of reduction and cut-out. Here, we investigated the usefulness of IHNs with an anterior offset (Best Fit Nail® [BFN]) in maintaining fragment reduction and ensuring proper lag screw position compared with conventional non-offset nails (Proximal Femoral Nail Antirotation® [PFNA]), using postoperative computed tomography (CT).

Methods

Fifty consecutive patients with intertrochanteric fractures who underwent surgery with BFNs (BFN group) and 50 patients who underwent surgery with PFNAs (PFNA group) were retrospectively analyzed. Indices evaluated by postoperative CT were displacement distance of proximal fragment relative to distal fragment, reduction status (intramedullary, anatomical, and extramedullary types), lag screw direction, and angle between lag screw and femoral neck axis (deviation angle).

Results

Median [interquartile range] displacement distance was significantly smaller in the BFN group (0 [0, 0] mm) compared with the PFNA group (5.2 [3.6, 7.1] mm) (p<0.001). Reduction status was significantly better in the BFN group (anatomical type, 40 cases; intramedullary type, in 9 cases, and extramedullary type in 1 case) than in the PFNA group (anatomical type, 6 cases; intramedullary type, 43 cases; extramedullary type, 1 case) (p<0.001). Deviation of lag screw direction was observed in significantly fewer cases in the BFN group (20 cases; 40%) compared with the PFNA group (36 cases; 72%). Lag screw deviation angle was significantly smaller in the BFN group (−0.71°±4.0°) compared with the PFNA group (6.9°±7.1°). No adverse events related to surgery were observed in either group.

Conclusions

Intertrochanteric fracture surgery using offset BFNs exhibited significantly smaller displacement distance, better reduction status, and higher frequency of no deviation with central lag screw position, compared with surgery using non-offset PFNAs.

Association between Immediate Postoperative Radiographic Findings and Failed Internal Fixation for Trochanteric Fractures: Systematic Review and Meta-Analysis

Failed internal fixations for trochanteric fractures have a strong negative impact owing to increased postoperative mortality and high medical costs. However, evidence on the prognostic value of postoperative radiographic findings for failed internal fixations is limited. We aimed to clarify the association between comprehensive immediate postoperative radiographic findings and failed internal fixation using relative and absolute risk measures. We followed the meta-analysis of observational studies in epidemiology guidelines and the Cochrane handbook. We searched specific databases in November 2021. The outcomes of interest were failed internal fixation and cut-out. We pooled the odds ratios and 95% confidence intervals using a random-effects model and calculated the number needed to harm for each outcome. Thirty-six studies involving 8938 patients were included. The certainty of evidence in the association between postoperative radiographic findings and failed internal fixation or cut-out was mainly low or very low except for the association between intramedullary malreduction on the anteromedial cortex and failed internal fixation. Moderate certainty of evidence supported that intramedullary malreduction on the anteromedial cortex was associated with failed internal fixation. Most postoperative radiographic findings on immediate postoperative radiographs for trochanteric fractures were uncertain as prognostic factors for failed internal fixations.

Long-term outcomes of distal locking in extracapsular fractures treated with trochanteric Gamma3 nails

BACKGROUND

Few publications have assessed long-term results of distal locking of short endomedullary nails for extracapsular hip fracture. Virtually all of them focus on immediate differences. Criteria for the use of static or dynamic locking are unclear in most nailing systems, and use is advised in unstable fracture patterns or with risk of bell-clapper effect, but often influenced by the "orthopaedic school".

MATERIALS AND METHODS

This is a historical cohort study on patients diagnosed and operated in 2014 and followed up until endpoint, considered as consolidation or major complication, plus evaluation of overall long-term survival. They were categorised as static distal locking (ST) or dynamic distal locking (DN). Both are comparable, except for all stable pre-operative classifications, Fracture Mobility Score (FMS) at discharge, and immediate post-operative loading, all of which were in favour of DN.

RESULTS

Consolidation took place in > 95% of patients, with a non-statistically significant delay trend in ST. Less than 6% in both ST and DN had major complications, with no differences. Most cases suffered early cut-out. Significant fracture collapse was the most frequent minor complication. There were more statistically significant minor and total complications in ST. Infection, without differences, can precede cut-out. Lateral thigh pain was similar and could be related to back-out. In DN, 21.1% of cases were truly dynamised. We did not find differences in mobility or in long-term survival.

CONCLUSIONS

Any type of distal locking seems to be safe for consolidation, despite a slightly longer consolidation time in static locking. Early cut-out was the main complication, while others were very infrequent, which is an advantage over helical blade devices. There was a higher rate of minor and overall mechanical complications in ST, but infection and lateral thigh pain were similar. Most non-traumatic mechanical complications occurred around 5-6 weeks. About one in five of the DN truly dynamised, with all cases occurring before 8 weeks. Mobility until endpoint and overall long-term survival were not influenced by the locking mode used.

LEVEL OF EVIDENCE

Therapeutic study, level 2b.

Outcomes of Wedge Wing in the Lag Screw for Unstable Intertrochanteric Fractures in Elderly Patients

Purpose

To evaluate clinical-functional and radiologic outcomes of elderly patients with an unstable intertrochanteric femur fracture treated with a wedge wing in the lag screw.

Materials and Methods

Forty-eight patients treated with the Dyna Locking Trochanteric nail (DLT nail) to resolve an unstable intertrochanteric femur fracture were reviewed retrospectively. Based on AO/OTA classification, Fracture 31-A2 (34 cases) and 31-A3 (14 cases) were included in the analysis. We measured the femoral neck-shaft angle, tip-apex distance (TAD), Cleveland index, sliding distance of the lag screw, and time to the fracture union. The Harris Hip Score and Paker and Palmer's mobility score for clinical evaluation were used.

Results

The mean follow-up period was 21.4 months (range, 12–34 months). The postoperative state of reduction was good in 28 cases and acceptable in 20 cases. The mean TAD was 20.5 mm. The position of the lag screw was center-center in 30 cases and center-inferior in 18 cases. The mean sliding distance of the lag screw was 3.4 mm at the last follow-up. The mean union time was 4.5 months. Two cases had complications which included a cut-out (1 case) and non-union (1 case). The mean Harris Hip Score was 86.5±8.3 (range, 76–90). Walking ability in 34 of the cases (70.8%) at last follow-up was similar to that prior to fracture.

Conclusion

Functional and radiological outcomes are satisfactory using the DLT nail in the treatment of elderly patients with unstable intertrochanteric fractures; however, wedge wing in the lag screw does not prevent implant-related complications.

Simple guidelines for evaluating intraoperative alignment after the reduction of intertrochanteric fractures

The incidence of intertrochanteric femoral fractures has rapidly increased with the extended lifespan of the elderly population. Surgery enables early ambulation by achieving anatomic reduction and stable internal fixation. However, reduction usually involves postoperative evaluation. Here, we present reliable parameters obtained from analyses of three-dimensional computed tomography images from cadavers to serve as guidelines during the reduction of intertrochanteric fractures. We included 184 three-dimensional modeling samples from cadavers placed in two standardized positions, similar to C-arm imaging. We recorded the level of the orthogonal line from the greater trochanter (GT) tip to the femoral head (GT orthogonal line [GTOL]) in the anteroposterior view and the line along the anterior femoral cortex passing through the femoral head (anterior cortical line) in the axial view. Correlations between these lines and angular alignments were statistically determined. The GTOL passed above the femoral head center at mean 2.36 mm in all patients; 77.17% of such instances were in the upper second quadrant of the femoral head. The anterior cortical line passed under the femoral head center at mean 10.82 mm; 73.37% of such instances were in the inferior one-third of the femoral head. Consistent correlations were found between the GTOL and neck-shaft angle and between the anterior cortical line and anteversion. The GTOL and anterior cortical line passed through a constant level of the femoral head in most samples and were correlated with angular alignments. The intraoperative use of these simple imaginary lines improves the intertrochanteric fracture reduction quality.

Clockwise Torque of Sliding Hip Screws: Is There a Right Side?

OBJECTIVES

This study evaluated whether patients with a left-sided femoral neck fracture (FNF) treated with a sliding hip screw (SHS) had a higher implant failure rate than patients treated for a right-sided FNF. This was performed to determine the clinical relevance of the clockwise rotational torque of the femoral neck lag screw in a SHS, in relation to the rotational stability of left and right-sided FNFs after fixation.

METHODS

Data were derived from the FAITH trial and Dutch Hip Fracture Audit (DHFA). Patients with a FNF, aged ≥50, treated with a SHS, with at least 3-month follow-up data available, were included. Implant failure was analyzed in a multivariable logistic regression model adjusted for age, sex, fracture displacement, prefracture living setting and functional mobility, and American Society for Anesthesiologists Class.

RESULTS

One thousand seven hundred fifty patients were included, of which 944 (53.9%) had a left-sided and 806 (46.1%) a right-sided FNF. Implant failure occurred in 60 cases (3.4%), of which 31 were left-sided and 29 right-sided. No association between fracture side and implant failure was found [odds ratio (OR) for left vs. right 0.89, 95% confidence interval (CI) 0.52-1.52]. Female sex (OR 3.02, CI: 1.62-6.10), using a mobility aid (OR 2.02, CI 1.01-3.96) and a displaced fracture (OR 2.51, CI: 1.44-4.42), were associated with implant failure.

CONCLUSIONS

This study could not substantiate the hypothesis that the biomechanics of the clockwise screw rotation of the SHS contributes to an increased risk of implant failure in left-sided FNFs compared with right-sided fractures.

LEVEL OF EVIDENCE

Therapeutic Level II.See Instructions for Authors for a complete description of levels of evidence.

A mathematical simulation of the tip-apex distance and the calcar-referenced tip-apex distance for intertrochanteric fractures reduced with lag screws

BACKGROUND

As a predictor of the risk of lag screw cutout, it was recommended that keeping tip-apex distance (TAD)<25mm and placing the screw centrally or inferiorly, but positioning the lag screw too inferiorly in the head would produce TAD>25mm. We aim to simulate various positions of the lag screw in the femoral head and identify whether 25mm is a suitable cut-off value that favours all sizes of femoral heads with intertrochanteric fractures of the hip.

METHODS

Using a general mathematical software, the positions of the screw tip points were simulated. The virtual anterior-posterior and lateral views were then visualised, and the locus of the screw tips was projected into a Cartesian coordinate system according to the TAD and calcar-referenced tip-apex distance (CalTAD) formulas. Each original virtual anterior-posterior and lateral image was zoomed and compiled to match a calculated average image. The screw tip points were recorded, traced and compiled into volumes which could be used to visualise the screw's movements and positioning within the femoral head. The extracted volumes were calculated when 10mm<TAD<25mm and 10mm<CalTAD<25mm, and the region where these two volumes overlapped was also calculated. Suitable positions for the screw tip were then assessed.

RESULTS

For the TAD calculation, the shape of the traced screw tip points had a pancake-like appearance, while the CalTAD plot produced a teardrop-shaped region. The volume ratios of TAD, CalTAD and overlapping region relative to the femoral head volume were respectively 3.51±1.30%, 5.19±1.62% and 2.64±1.32%. The volumes of the traced TAD, CalTAD and overlapping regions increased slower than the volume of an idealised sphere.

CONCLUSION

Positioning the lag screw should address geometrical effects of both tip-apex distance and femoral head size, with an emphasis on measuring the position of the screw tip for the suitable zone by volume ratio. The previous 25mm TAD cut-off value should be adjusted according to the individual femoral head size.

Analysis of trabecular bone microstructure in osteoporotic femoral heads in human patients: in vivo study using multidetector row computed tomography

BACKGROUND

Lag screw position is very important in the treatment of intertrochanteric femoral fracture to prevent complications such as screw cut-out. Current studies recommend central or inferior placement of the lag screw on the anteroposterior radiograph, and central placement on the lateral radiographs. These reports are based on radiographic evaluation, but few studies have investigated the importance of bone quality at the site of lag screw placement. In this study, we used multidetector row computed tomography (MDCT) to perform in vivo evaluation of the bone microstructure of the femoral head in patients with intertrochanteric femoral fractures.

METHODS

This study was approved by the Ethics Committee of Okanami General Hospital. MDCT images were obtained in our hospital from ten patients who had sustained intertrochanteric femoral fracture. Patients who needed computed tomography to confirm fracture morphology were included. We defined six areas as regions of interest (ROI): ROI 1-3 were defined as the femoral head apex area, and ROI 4-6 were defined as the femoral neck area. Trabecular microstructure parameters, including mean bone volume to total volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), and structure model index (SMI), were evaluated with bone analysis software (TRI/3D-BON). Statistical analyses were performed using EZR software; each parameter among the ROIs was statistically evaluated by analysis of variance (ANOVA) and Tukey's test. Statistical significance was established at p < 0.05.

RESULTS

In the apical area, all parameters indicated that ROI 1 (superior) had the highest bone quality and ROI 2 (central) was higher in bone quality than ROI 3 (inferior). In the femoral neck, all parameters indicated that bone quality was significantly greater in ROI 6 (inferior) than ROI 5 (central).

DISCUSSION AND CONCLUSIONS

We could evaluate bone quality with clinical MDCT in vivo. Bone quality in the central area of the femoral head apical was greater than in the inferior area, and bone quality in the inferior area of the femoral neck was greater than in the central area. Recognizing which area of femoral head has greater bone quality may lead to a better clinical result in treating intertrochanteric femoral fracture.

How evolution of the nailing system improves results and reduces orthopedic complications: more than 2000 cases of trochanteric fractures treated with the Gamma Nail System

PURPOSE

The incidence of trochanteric fractures has increased significantly during the last few decades, especially in elderly patients with osteoporosis. The dynamic/sliding hip screw and the cephalomedullary nail are the most commonly used fixation methods to treat trochanteric fractures. The improvements in the Gamma Nail System (GNS) associated with a correct surgical technique reduced the postoperative orthopedic complications. The purpose of this study was to compare the results of the different Gamma Nails.

METHODS

The present study is a retrospective analysis of 2144 patients treated with GNS between January 1997 and December 2011 for trochanteric fractures, classified according to AO classification method. The patients were divided into three groups according to the nailing system: 525 were treated with Standard Gamma Nail (SGN), 422 with Trochanteric Gamma Nail (TGN) and 1197 with Gamma3 Nail.

RESULTS

The overall incidence of intra-operative complications was 1.21 %; the incidence of intra-operative complications for each group was 1.71 % for SGN group, 0.47 % for TGN group and 1.25 % for Gamma3 Nail group. The overall incidence of postoperative complications was 5.48 %, and the incidence for each group was 10.73 % for SGN group, 9.92 % for TGN group and 2.92 % for Gamma3 Nail group.

CONCLUSION

The GNS is a safe device with a low rate of intra-operative complications. The evolution of this nail system reduces postoperative complications, thus improving the results at follow-up and confirming that the Gamma3 Nail is a safe and predictable device to fix trochanteric fracture.

Precise placement of lag screws in operative treatment of trochanteric femoral fractures with a new guide system

PURPOSE

We assessed the accuracy of a new guide system that we developed to place lag screws in the proper position with the minimum number of attempts for operative treatment of trochanteric femoral fractures.

METHODS

A total of 55 consecutive trochanteric femoral fractures were treated with a cephalomedullary nail. The first 27 consecutive patients were treated with the standard operation (group A), while the new guide system was used in the last 28 consecutive patients (group B). The numbers of attempts to place K wires and the duration of surgery were noted. Accuracy of lag screw placement was evaluated by measuring the angle of deviation from the central axis of the femoral head.

RESULTS

Deviation values ranged from -11̊ to +15̊ for the 27 cases in group A, with a median absolute deviation of 8̊±6̊. That in the 28 cases after the introduction of the new guide system (group B) ranged from -5̊ to +6̊, with a median absolute deviation of 0.5̊±3̊ (P<0.001). The total numbers of attempts to place lag screws and mean operation time decreased significantly after introduction of the new guide system (P<0.001).

CONCLUSIONS

With this new guide system, we are able to insert lag screws successfully in the optimal position even in most unstable fractures. The present study indicated that this new guide system and nail facilitate accurate placement of lag screws in the appropriate position with the minimum number of attempts.

Changes in Tip-Apex Distance by Position and Film Distance Measured by Picture Archiving and Communication System (PACS)

PURPOSE

The tip-apex distance (TAD) is used to predict the clinical outcome of intertrochanteric fracture fixation. We aimed to measure the changes in TAD by position and film distance using Picture Archiving and Communication System (PACS).

MATERIALS AND METHODS

We used a femur replica with a 10° femoral neck anteversion and a 130° neck shaft angle. Proximal femoral nail antirotation nail and a helical blade were inserted into the replica. Radiographs were taken at the neutral position and after applying 10°, 20°, 30°, 40° internal/external rotation, 10° abduction, and 10° and 40° adduction to the mechanical axis. Radiographs were taken at the replica-film distance of 10 cm and 20 cm under the same conditions, mimicking the differences in Focus-film distance (FFD), which reflect the patient's contour in clinical settings. A radiologist and an orthopedic surgeon measured the TAD twice using PACS. The average error was 2 mm (4.5%) and the standard error was ±3.04. TADs in the neutral position constituted the standard values to measure the relative errors.

RESULTS

TADs increased with an increase in the external rotation and abduction of the replica. TADs decreased with an increase in the internal rotation and adduction of the replica. For comparable measurements, relative errors were higher at FFDs of 20 cm compared to FFDs of 10 cm.

CONCLUSION

Since the femur is internally rotated and adducted for reduction, orthopedic surgeons would assess the lag screw to be closer to the apex of femur on intraoperative radiographs. To have a correct measurement of the TAD after fixation of intertrochanteric fractures, radiographs should be taken in neutral position and measurement errors should be considered based on the patient's size.

Early Complications in Proximal Femoral Nailing Done for Treatment of Subtrochanteric Fractures

ABSTRACT

AIM

To analyse the early complications following the use of PFN in subtrochanteric fractures.

BACKGROUND

Osteosynthesis with PFN in subtrochanteric fracture features the advantages of high rotational stability of the head-neck fragment, an unreamed implantation technique and the possibility of static or dynamic distal locking. However, the use of the nail requires technical expertise and is accompanied by some risks of error which can lead to osteosynthesis failure.

METHODS

Between May 2009 and May 2011, 50 consecutive patients with PFN fixations for subtrochanteric fractures were observed for intraoperative and postoperative complications.

RESULTS

We identified intraoperative technical difficulties in four patients and six patients showed postoperative complications.

CONCLUSION

When subtrochanteric fractures are to be stabilised with a PFN, the precise and expert technical performance of implantation is the basic surgical requirement. Good reduction with minimal dissection and the use of an appropriate implant is necessary to avoid treatment failure.

KEY WORDS

Subtrochanteric fractures, trochanteric fractures, proximal femoral nail, PFN.

Improved lag screw positioning in the treatment of proximal femur fractures using a novel computer assisted surgery method: a cadaveric study

Background

The importance of the tip-apex distance (TAD) to predict the cut-out risk of fixed angle hip implants has been widely discussed in the scientific literature. Intra-operative determination of TAD is difficult and can be hampered by image quality, body habitus, and image projection. The purpose of this paper is to evaluate, through a cadaveric study, a novel computer assisted surgery system (ADAPT), which is intended for intraoperative optimisation of lag screw positioning during antegrade femoral nailing. A 3D measure for optimal lag screw position, the tip-to-head-surface distance (TSD), is introduced.

Methods

45 intra-medullary hip screw procedures were performed by experienced and less experienced surgeons in a cadaveric test series: in 23 surgeries the ADAPT system was used, and in 22 it was not used. The position of the lag screw within the femoral head and neck was evaluated using post-operative CT scans. TAD, TSD, fluoroscopy as well as procedure time and variability were assessed.

Results

The use of the ADAPT system increased accuracy in TSD values (i.e. smaller variability around the target value) for both groups of surgeons (interquartile range (IQR) of experienced surgeons: 4.10 mm (Conventional) vs. 1.35 mm (ADAPT) (p = 0.004)/IQR of less experienced surgeons: 3.60 mm (Conventional) vs. 0.85 mm (ADAPT) (p = 0.002)). The accuracy gain in TAD values did not prove to be significant in the grouped analysis (p = 0.269 for experienced surgeons; p = 0.066 for less experienced surgeons); however, the overall analysis showed a significant increase in accuracy (IQR: 4.50 mm (Conventional) vs. 2.00 mm (ADAPT) (p = 0.042)). The fluoroscopy time was significantly decreased by the use of the ADAPT system with a median value of 29.00 seconds (Conventional) vs. 17.00 seconds (ADAPT) for the less experienced surgeons (p = 0.046). There was no statistically significant impact on the procedure time (p = 0.739).

Conclusions

The ADAPT system improved the position of the lag screw within the femoral head, regardless of the surgeon’s level of clinical experience, and at the same time decreased overall fluoroscopy usage. These positive effects are achieved without increasing procedure time.

Malpositioning of the lag screws by 1- or 2-screw nailing systems for pertrochanteric femoral fractures: a biomechanical comparison of gamma 3 and intertan

OBJECTIVES

The aim of this investigation was to perform a biomechanical comparison between 1- and 2-screw systems used for the treatment of intertrochanteric fractures for centralized and decentralized placement of femoral neck screws of failure loads, stiffness, survival rates, tip apex distance (TAD), and failure mode.

METHODS

As fracture model, an AO 31A2.3 fracture was used. Twelve pairs of human cadaver femora were tested. Femoral neck screws were implanted in the femoral head in center/center, posterior/central, and anterior/superior position in axial/frontal plane. A single-screw system (Gamma 3 Locking Nail; Stryker GmbH & Co. KG) and a 2-screw system (Trigen-Intertan; Smith & Nephew GmbH) were used. To simulate the load in situ, a cyclic load was carried for 10,000 cycles in a material testing machine. If no cyclic failure occurred, femora were loaded until the failure. The systems were compared according to the stiffness, survivability through 10 k cycles, TAD, and load to failure.

RESULTS

None of the tested bones failed at center/center location in the decentralized positions 3 Gamma Nail and 2 Intertan specimens failed during cyclic testing. The 2-screw system resisted higher forces in all positions (Gamma: 5370N ± 1924, Intertan: 7650N ± 2043; P = 0.014).

CONCLUSIONS

Based on these data, it is clear that both the nail systems showed a higher biomechanical stability with a lower TAD. The 2 specimens that failed with the Intertan in the cyclic tests had a TAD ≥49 mm. The cutout failures that we detected during cyclic testing in the Gamma system had a TAD ≥30 mm. Thus, it is clear that the TAD affects failure independent of the implant used. With a less than ideal lag screw placement, however, the Intertan system with 2 integrated screws was able to withstand higher loads in this study.

How to prevent cut-out and cut-through in biaxial proximal femoral nails: is there anything beyond lag screw positioning and tip-apex distance?

PURPOSE

Hip perforation is a major complication in proximal femoral nailing. For biaxial nails, knowledge of their biomechanics is limited. Besides re-evaluation of accepted risk factors like the tip-apex distance (TAD), we analysed the influence of anti-rotational pin length.

METHODS

We compared 22 hip perforation cases to 50 randomly chosen controls. TAD, lag-screw position, angle between lag-screw and femoral neck axis, lag-screw gliding capacity, displacement and anti-rotational pin length were investigated.

RESULTS

Hip perforation was associated with a higher angle of deviation between lag-screw and femoral neck axis (p = 0.001), a lower telescoping capacity of the lag screw (p = 0.02), and higher TAD (p = 0.048). If the anti-rotational pin exceeded a line connecting the tip of the nail and the lag screw (NS line), hip perforation incidence was increased (p = 0.009). Inadequate pin length resulted in an odds ratio of 10.8 for hip perforation (p = 0.001).

CONCLUSIONS

In biaxial nails anti-rotational element positioning is underestimated, however, crucial.

Critical factors in cut-out complication after Gamma Nail treatment of proximal femoral fractures

BACKGROUND

The most common mechanical failure in the internal fixation of trochanteric hip fractures is the cut-out of the sliding screw through the femoral head. Several factors that influence this complication have been suggested, but there is no consensus as to the relative importance of each factor. The purpose of this study was to analyse the cut-out complication with respect to the following variables: patients' age, fracture type, fracture reduction, implant positioning and implant design.

METHODS

3066 consecutive patients were treated for trochanteric fractures with Gamma Nails between 1990 and 2002 at the Centre de Traumatologie et de l'Orthopedie (CTO), Strasbourg, France. Cut-out complications were identified by reviewing all available case notes and radiographs. Subsequently, the data were analysed by a single reviewer (AJB) with focus on the studied factors.

RESULTS

Seventy-one cut-out complications were found (2.3%) of the 3066 trochanteric fractures. Cut-out failure associated with avascular head necrosis, pathologic fracture, deep infection or secondary to prior failure of other implants were excluded from the study (14 cases). The remaining 57 cases (1.85%, median age 82.6, 79% females) were believed to have a biomechanical explanation for the cut-out failure. 41 patients had a basicervical or complex fracture type. A majority of cut-outs (43 hips, 75%) had a combination of the critical factors studied; non-anatomical reduction, non-optimal lag screw position and the characteristic fracture pattern found.

CONCLUSIONS

The primary cut-out rate of 1.85% was low compared with the literature. A typical cut-out complication in our study is represented by an unstable fracture involving the trochanteric and cervical regions or the combination of both, non-anatomical reduction and non-optimal screw position. Surgeons confronted with proximal femoral fractures should carefully scrutinize preoperative radiographs to assess the primary fracture geometry and fracture classification. To reduce the risk of a cut-out it is important to achieve both anatomical reduction and optimal lag screw position as these are the only two factors that can be controlled by the surgeon.

Central head perforation, or "cut through," caused by the helical blade of the proximal femoral nail antirotation

OBJECTIVE

This study was designed to investigate the specific type and incidence of implant failure in patients with a proximal femur fracture treated with a proximal femoral nail antirotation. This device has a helical-shaped blade as a neck-head holding device, instead of the lag screw used in other intramedullary nails. The advantage of the blade is believed to originate from bone impaction and a larger bone-implant interface in comparison with the lag screw design, with consequential greater mechanical resistance to torsion in the cancellous bone.

PATIENTS AND METHODS

This is a retrospective cohort study conducted at the state hospital of Winterthur, Switzerland. From December 2006 until November 2008, 210 consecutive patients were treated with a pertrochanteric femur fracture (OTA type 31-A1, 31-A2, and 31-A3) using a proximal femoral nail antirotation. One hundred and twelve patients were followed up clinically for a minimum of 12 months after discharge. Clinical and radiologic assessment of fracture healing and/or implant failure was investigated.

RESULTS

We report 7 cases of implant failure with a "Cut Through," defined as a postoperative central perforation of the spiral blade into the hip joint, without any displacement of the neck-head fragment.

CONCLUSIONS

Cut through needs to be distinguished from the well-known anterocranial perforation combined with a varus displacement of the neck-head fragment, known as "Cut Out," seen with intramedullary nails utilizing lag screws.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Is proximal femoral nailing a good procedure for teaching in orthogeriatrics?

BACKGROUND

Proximal femoral nailing is a common operation in orthogeriatrics and a highly standardized procedure. For teaching purposes, this operation is often performed by residents and supervised by attending physicians. The objective of this study is to investigate if teaching this operation influences the surgical in-house complication rate.

PATIENTS AND METHODS

All patients who received a proximal femoral Targon PF nail (Aesculap AG, Tuttlingen, Germany) for trochanteric fractures were included in a cohort at our urban academic teaching hospital between 1998 and 2010. To evaluate potential effects of patient age, we separately analyzed several age groups. Complications including wound infection, hematoma, intraoperative malreduction or implant malpositioning causing revision, pain, cut-out and readmission due to nonunion were recorded.

RESULTS

Our collective consists of 1,516 patients (m/f: 410/1,106). The mean age was 78.7 years (range: 19-103 years). The overall complication rate was 7.9 %. In 857 cases operated by attending physicians, the complication rate was 6.9 %. However in the 659 operations performed by residents, we found a higher complication rate of 9.3 %. Further investigating this difference by χ(2) test, we found no significance (p = 0.09). Whilst analyzing the complication rates for the different age groups, we did not find a statistically significant difference except in the age group between 71 and 80 years, for which the odds ratio indicated a 2.6-fold increased complication risk for operations performed by residents (p = 0.01). Further analysis revealed that this increased complication rate was mainly due to increased numbers of cut-out.

CONCLUSION

We conclude that proximal femoral nailing is an operation suitable for teaching purposes. However, patients between 71 and 80 years of age seem to be at an increased risk for cut-out if operated by a resident.

Occurrence of secondary fracture around intramedullary nails used for trochanteric hip fractures: a systematic review of 13,568 patients

INTRODUCTION

A sliding hip screw (SHS) is currently the treatment of choice for trochanteric hip fractures, largely due to the low incidence of complications. An alternative treatment is the use of intramedullary proximal femoral nails. Unfortunately these implants have been associated with a risk of later fracture around the implant. The aim of this study was to see if any improvements have been made to the current intramedullary nails, to reduce the incidence of secondary fracture around the distal tip of the nail.

METHODS

We analysed data related to 13,568 patients from 89 studies, focusing on the incidence of post operative secondary femoral shaft fracture following the use of intramedullary nails in the fixation of trochanteric hip fractures.

RESULTS

The overall reported incidence of secondary fracture around the nail was 1.7%. The incidence of fracture has reduced in the 3rd generation Gamma nails when compared to the older Gamma nail (1.7% versus 2.6%, p value 0.03). However, the incidence of secondary fracture in the 3rd generation Gamma nails is still significantly higher than the other brands of short nail (1.7% versus 0.7%, p value 0.0005). Long nails had a slight tendency towards a lower risk of fracture although the difference was not statistically significant (1.1% versus 1.7%, p value 0.28). There was a significantly lower risk of fracture for those nails with a biaxial fixation as opposed to uniaxial fixation (0.6% versus 1.9%, p value <0.0001).

CONCLUSION

Secondary fracture around a proximal femoral nail is one of the most significant of fracture healing complications, and this study suggests that continuing design changes to this method of fixation has reduced the risk of this complication occurring.

Clinical results of trochanteric fractures treated with the TARGON® proximal femur intramedullary nailing fixation system

The aim of this study was to investigate the outcome of 352 (71 males) patients with trochanteric fractures that were treated with the TARGON® PF nail. The mean age was 83 years. According to the Jensen classification, there were 35 cases in type 1,94 cases in type 2,75 in type 3,63 in type 4 and 85 in type 5. Postoperative all patients were allowed to fully weight bear from the first postoperative day. Clinical and radiological data were collected at regular time intervals. The average waiting time to surgical reconstruction for the 352 cases was 3.5 days (1-7). The mean length of hospital stay was 14 days (5-22). The operative times ranged from 11 to 125 minutes with an average time of 32 minutes. Fifty percent of the patients regained their mobility to their pre-injury level at the final follow up. Out of 310 patients (88%) who were available for radiographie assessment, all fractures united except one case. 300 (85%) of the lag screws were placed in the inferior area in the anteroposterior view and in the central area in the lateral view (IM), which is regarded as the optimal position. The lag screws back-slided between 0 and 19 mms with an average of 6 mm. Sliding distance of the lag screw for over 10 mm was seen in 42 cases (13%). Varus collapse of the femoral head-and-neck greater than 10° was observed in 6 cases. Postoperative complications developed in 6 cases (1.7%), including wound infection in two cases, and secondary fracture at the subtrochanteric region, nonunion, back-out of the guiding sleeve and medial perforation of the lag screw, each in one case. The presented case series indicates that the TARGON® PF system is an effective and safe internal fixation device for trochanteric proximal femoral fractures. Further, prospective comparative evidence regarding the use of this system is needed to analyse and validate the presented clinical impression of our centre.

Predictive factors for cutting-out in femoral intramedullary nailing

BACKGROUND

Femoral intramedullary nailing is currently one of the most frequent surgical treatments for extracapsular hip-fracture fixation. Cutting-out of the lag screw is the main complication of this technique, but only few studies have approached the cutting-out focussed on femoral nailing. The aim of this study was to confirm in patients treated with intramedullary nailing not only with regard to previous reports about the association of cutting-out with technical factors, but also with regard to clinical factors not previously studied.

METHODS

Case-control study of all patients sustaining a cut-out of the femoral nail was carried out and a control sample was randomly selected among all extracapsular hip-fracture patients during the study period (2005-2008). All clinical and technical variables were collected from medical records. Orthopaedic Trauma Association (AO/OTA) fracture classification, Singh Osteoporosis Index of the contralateral hip and the American Society of Anaesthesiology (ASA) criteria for preoperative clinical status were used. Statistical assessment included bivariant analysis and multivariant logistic regression analysis.

RESULTS

A total of 916 hip-fracture cases were treated in the study period: 33 of them (3.6%) were identified as suffering cutting-out, and 315 controls fulfilling inclusion criteria were also recruited. No statistical differences were found in age, sex or other socio-demographic variables between the two groups. Bivariant analysis showed significant differences between groups in technical variables (tip-apex distance, suboptimal placement of lag screw, fracture diastasis, inadequate fixation quality and distal static locking) and in clinical variables (osteoporosis severity, right hip affected, better previous ability for walking and better preoperative ASA status). Multivariant logistic regression analysis showed significant association only for tip-apex distance and inadequate fixation quality. Differences in distal static locking were close to statistical significance.

CONCLUSIONS

The strongest predictor of cutting-out in femoral nailing is tip-apex distance. This study suggests that distal static locking and other clinical conditions play an important role in this fixation failure.

The new technique of precise insertion of lag screw in an operative treatment of trochanteric femoral fractures with a short intramedullary nail

In order to reduce the incidence of cut-out, which is one of the serious postoperative complications of trochanteric femoral fractures, we paid special attention to the placement of lag screw in the femoral head. As a result, we devised a new technique that allows insertion of the lag screw at the first attempt into the optimal position on both planes, inferior half on the antero-posterior view and exactly central on the lateral view, without the need for any special devices other than the basic original set, using a trochanteric nail. For this technique, we have evaluated the proximal femoral profile under image intensifier, on the true lateral view projected parallel to the axis of the femoral neck and not on the conventional lateral view (Lauenstein view) with the projection parallel to the axis of the femoral shaft in a coronal plane. With the X-ray beam lying in the same plane with the targeting device including the nail and the guide sleeve, the guide pin is intended to pass through the guide sleeve and the middle of shadow of the proximal end of the targeting device, so that it can be inserted in the optimal position without fail, aligned with the middle axis of the femoral head. The deviation angle between the axes of the lag screw and the femoral head was measured on every postoperative lateral radiograph. The mean deviation angle of 1.6 degrees in the 39 fractures after the introduction of the new insertion technique was compared with 4.8 degrees in the 44 fractures before the introduction, which showed a significant difference between these groups (p<0.0001, Welch's t-test). When the lag screw can be placed exactly in the centre of the femoral head on the true lateral view, it can be set forward as closest to articular surfaces as possible on the postero-anterior view without a risk of penetration, so that the tip-apex distance could be easily achieved under 20mm, which leads to a reduction of postoperative cut-outs. This technique can be applied in other similar trochanteric nails, which gives them an advantage over the sliding hip screws.

Accuracy of lag screw placement for the dynamic hip screw and the cephalomedullary nail

The outcome of peritrochanteric fracture fixation is dependent on lag screw placement in the femoral head. The dynamic hip screw technique permits initial, independent lag screw placement, while the cephalomedullary nail dictates its positioning. The objective of this study was to compare the accuracy of lag screw placement for both implant types. A retrospective review of 200 consecutive patients with peritrochanteric fractures stabilized with a dynamic hip screw or cephalomedullary nail was performed. Postoperative biplanar radiographs were used to determine the lag screw tip-apex distance and femoral head zone placement. The study inclusion criteria were met by 137 patients (66 dynamic hip screw; 71 cephalomedullary nail). The patients included 56% women and 44% men with an average age of 73 years. The tip-apex distance and femoral head zone placement demonstrated no statistically significant difference between the 2 implant groups. The lag screw of a cephalomedullary nail was 3.25 times more likely placed in the antero-center zone compared to the dynamic hip screw, and this was statistically significant when compared to other zones. There was a trend toward a more favorable tip-apex distance in women for both implants. The accurate placement of the lag screw can be routinely achieved for both dynamic hip screw and cephalomedullary nail implants, and therefore should not a factor in the selection of these implants for adequate peritrochanteric fracture stabilization. These results represent the immediate postoperative setting, and a follow-up is warranted to establish their long-term clinical relevance.

Influence of osteoporosis on fracture fixation--a systematic literature review

The goal of our systematic literature search was to prove whether the experimentally shown influence of osteoporosis on fracture fixation could be confirmed in clinical studies. Despite significant effects in several studies, this is not supported by pooled data due to lack of accurate osteoporosis assessment and complication definitions.

INTRODUCTION

The fact that osteoporosis causes fractures is well-known; the assumption that it aggravates their orthopaedic treatment has not been proven. The goal of our systematic literature search was to find out whether the experimentally proven influence of osteoporosis on fracture fixation could be confirmed in clinical studies.

METHODS

A systematic electronic database search was performed identifying articles that evaluated complications after fracture fixation among patients suspected of having osteoporosis as measured by BMD or surrogates including Singh index or risk factors. To determine complications risks (relative risk within 95% confidence interval) data were pooled across studies, weighted by sample size and stratified by treatment type.

RESULTS

Ten studies out of 77 randomized controlled trials (51 hip, 23 distal radius and three proximal humerus studies) and three systematic reviews finally met eligibility criteria. Despite significant differences of the relative complication risk between osteoporotic and non-osteoporotic patients in several studies, this could not be proven in the pooled data.

CONCLUSIONS

In contrast to biomechanical evidence that local osteoporosis affects anchorage of implants, this could not be reproduced in clinical studies, due to the lack of accurate osteoporosis assessment, missing complication definitions and heterogeneous inclusion criteria in these studies. Prospective studies are required that address specifically the correlation between local bone status and the risk of fixation failure.

Proximal femoral nail for treatment of trochanteric femoral fractures

PURPOSE

To report outcomes of 87 consecutive patients treated with a proximal femoral nail (PFN) for trochanteric femoral fractures.

METHODS

17 men and 70 women aged 58 to 95 (mean, 85) years with trochanteric femoral fractures underwent PFN fixation using an intramedullary nail, a lag screw, and a hip pin. Fractures were classified according to the AO system; the most common fracture type was A2 (n=45), followed by A1 (n=36) and A3 (n=6). The position of the lag screw within the femoral head was measured. The lateral slide of the lag screw after fracture consolidation was measured by comparing the immediate postoperative and final anteroposterior radiographs.

RESULTS

90% of lag screws were placed in an optimal position. The length of lateral slide of the lag screw in stable A1 fractures was significantly less than that in unstable A2 fractures; it was over 10 mm in 7 of 45 patients with A2 fractures. Cut-out of lag screw did not occur, suggesting that free sliding of the lag screw facilitates direct impaction between fragments.

CONCLUSION

A PFN is useful for the treatment of trochanteric femoral fractures.

Measurement of local strains induced into the femur by trochanteric Gamma nail implants with one or two distal screws

This study aims to evaluate experimentally the behaviour after fracture consolidation of two intramedullary Gamma nail implants, having one (G1) or two (G2) distal screws, respectively. Nails have been implanted into standardized synthetic femora, instrumented with strain gauges. Strains measurements, supported by finite element numerical modelling, showed that the G2 implant, although ensuring higher flexional and torsional stiffness, can lead to localized contacts that occur between the tip of the nail and the femoral endosteum. This might be one of the reasons of the complications associated with pain in the mid-portion of the thigh after implantation which has been reported in several clinical studies when Gamma nails with two distal screws are used.

Finite element study of the proximal femur with retained trochanteric gamma nail and after removal of nail

This study aims to evaluate the stress and strain distributions in the healed proximal femur after fixation with a trochanteric gamma nail (TGN) and after TGN removal, using the finite element method. The stress distributions in the proximal femur with retained TGN and after TGN removal were very similar. The strain and the strain energy density in the femoral neck region with retained TGN were much higher than in the lag screw hole at the subtrochanter and the distal locking screw hole at the proximal femur, and even higher after TGN removal. Stair climbing resulted in higher strain and higher strain energy density at the femoral neck than normal walking. The conclusion can be drawn that removal of the TGN may result in high risk of femoral neck fracture.

Comparison of accuracy of lag screw placement in cephalocondylic nails and sliding hip screw plate fixation for extracapsular fractures of the neck of femur

This study compared the accuracy of lag screw placement between extracapsular femoral fractures fixed with sliding hip screw plate systems and those fixed with cephalocondylic nails. It involved 75 retrospective radiographs of fractures fixed with either a cephalocondylic nail (32) or a sliding hip screw plate system (43). Postoperative anteroposterior and lateral radiographs of the hip were scanned using a digital X-ray scanner and measured using computer software. Measurements were conducted by two independent observers, and the radiographs were calibrated to correct for magnification. Accuracy of lag screw placement was determined by "tip apex distance," described by Baumgaertner et al., and by the ratio method described by Parker. The mean tip apex distance was 24.0 mm in sliding hip screw plate systems and 21.1 mm in cephalocondylic nails. This was found to be statistically significant. Lag screw placement through cephalocondylic nails is more accurate and therefore has less chance of cut-out compared with sliding hip screw plate systems. There was no statistically significant difference using Parker's ratio method because this method quantifies the direction of the screw rather than the depth of penetration.

Treatment of intertrochanteric fractures in geriatric patients with a modified external fixator

Forty-two geriatric patients who had an intertrochanteric fracture were treated with a semicircular modification of the Ilizarov frame designed by Cattaneo and Catagni between January 1997 and September 2001. Twenty-five of the patients were female, 17 male. The average age of the patients was 77.5 years (range, 63-99). No intraoperative complication occurred. Deep pin-track infection was found in four patients and varus deformity was observed in two patients and shortening of less than 2 cm in 10 patients. Fixator removal was achieved in a mean time of 12 weeks (range, 10-18). No implant failure, refracture or stiffness of knee and hip joint movements was recorded. We concluded that the treatment of intertrochanteric fractures of the elderly patients with our modification provides significant advantages such as minimal operative and anaesthetic risks, no blood loss, early weight-bearing, short hospitalisation time and rapid union time.

Treatment strategies for proximal femur fractures in osteoporotic patients

Fractures of the proximal end of the femur, together with vertebral fractures, are greatly exacerbated by osteoporosis and can be regarded as the most typical and most serious complications of this disease. The demand for prompt mobilisation with full loading of the affected limb, combined with a desire for the gentlest of treatments, becomes increasingly difficult to meet in ageing patients with advanced osteoporosis. The advantages of osteosynthesis in respect to these demands when operating on elderly patients with fractures do not apply due to the inability of the osteoporotic bone to hold the osteosynthetic components sufficiently until fracture healing occurs. This inability is related to the anatomy of the proximal end of the femur and its loading patterns. Under eccentric loading, high bending loads occur, leading to failure of the osteosynthetic anchorage at the center of the femoral head. This leads subsequently to stressful revision operations for the patient. The prosthetic replacement is a good option in cases of dislocated intracapsular fractures, but in cases of trochanteric fractures it is still debated. Therefore, it is vital for the trauma surgeon to have specific knowledge of the patient's bone quality in order to optimise the result of the preferred procedure. With reference to our own experimental research and a study of the current literature, this knowledge can be summarised as follows: the most stable anchorage for the implant is achieved by placing the implant through the midpoint of the femoral head (highest bone mineral density) or just below ("best backing"). Anchoring femoral head implants so that they are stable in rotation within the head-neck fragment will significantly raise their load bearing capacity. This is also true for intramedullary load bearing devices in trochanteric fractures. The distance between the load-bearing device in the femoral neck and the articular surface is inversely correlated to the stability at yield, as other studies have already shown. There seems to be a limit for a successful realisation of an osteosynthesis that lies at a femoral head bone mineral density of 250 mg/cm(3) calcium-hydroxyapatite (CaHAp). Nevertheless, high precision surgery in regard to fracture reduction and implant placement is a essential requirement for a successful osteosynthesis. Reproducible local measurements of bone mineral density and trabecular alterations, as well as quick screening methods, are very much desired by the authors.

Treatment of intertrochanteric hip fractures with the AO trochanteric fixation nail

Further biomechanical and clinical studies are necessary to validate the efficacy of the Trochanteric Fixation Nail, but in our experience this is an improvement over the currently available devices.

A laboratory model to evaluate cutout resistance of implants for pertrochanteric fracture fixation

OBJECTIVES

To establish a laboratory model of implant cutout, which can evaluate the effect of implant design on cutout resistance in a clinically realistic "worst case" scenario.

SETTING

Orthopaedic biomechanics laboratory.

DESIGN

Implant cutout was simulated in an unstable pertrochanteric fracture model, which accounted for dynamic loading, osteoporotic bone, and a defined implant offset. For model characterization, lag screw cutout was simulated in human cadaveric specimens and in polyurethane foam surrogates. Subsequently, foam surrogates were used to determine differences in cutout resistance between 2 common lag screws (dynamic hip screw, Gamma) and 2 novel blade-type implant designs (dynamic helical hip system, trochanteric fixation nail).

MAIN OUTCOME MEASURES

Implant migration was continuously recorded with a spatial motion tracking system as a function of the applied loading cycles. In addition, the total number of loading cycles to cutout failure was determined for specific load amplitudes.

RESULTS

Implant migration in polyurethane surrogates closely correlated with that in cadaveric specimens, but yielded higher reproducibility and consistent cutout failure. The cutout model was able to delineate significant differences in cutout resistance between specific implant designs. At any of 4 load amplitudes (0.8 kN, 1.0 kN, 1.2 kN, 1.4 kN) dynamic hip screw lag screws failed earliest. The gamma nail lag screw could sustain significantly more loading cycles than the dynamic hip screw. Of all implants, trochanteric fixation nail implants demonstrated the highest cutout resistance.

CONCLUSIONS

Implant design can significantly affect the fixation strength and cutout resistance of implants for pertrochanteric fracture fixation. The novel cutout model can predict differences in cutout resistance between distinct implant designs.

Intramedullary nails: some design features of the distal end

Intramedullary nails are used to stabilise fractures of the proximal femur. The nail acts by transferring loads from the proximal fraction to the rest of the femoral shaft. The way in which this occurs depends to a large extent on the design of the distal end of the nail. This is not dissimilar to the situation with regard to load shedding (or load transfer) from the femoral component of a total hip replacement. A finite element model of a fractured femur with either a neck or a subtrochanteric fracture is set up to investigate the effects of nail length, nail distal stiffness and material stiffness on the structural behaviour of the system. Specifically what is considered is the influence of these parameters on the stress across the fracture and the normal pressure that the nail exerts on the endosteum of the femoral diaphysis. It is found that a longer nail could produce higher contact stress between the tip of the nail and the endosteum. Also, this contact stress is reduced when the distal region of the nail is made more flexible either by incorporating longitudinal slots or by using a material with a lower modulus of elasticity.

Finite element study of trochanteric gamma nail for trochanteric fracture

A three-dimensional finite element study of trochanteric fracture fixation by a trochanteric gamma nail (TGN) was investigated in this study. The analyses were performed under one-legged stance load boundary conditions to study the stress distribution and displacements. The influence of material properties (E-modulus) of the implant, the bone and contact condition in the fracture zone was determined. The results show that the stresses in the implant were lower in case of titanium alloy implant material but at the same time higher displacements occurred. The results also indicate that the stresses in the TGN gradually reduced throughout the healing process of the bone in the fracture zone.

Necrosis of the femoral head after fixation of trochanteric fractures with Gamma Locking Nail. A cause of late mechanical failure

Cut-out of the lag screw after fixation of trochanteric fractures with intramedullary devices like the Gamma Locking Nail is a well documented cause of late mechanical failure. Avascular necrosis of the femoral head after trochanteric fractures is an uncommon complication and several causes have been described. As far as we know, the relation of the mechanical failure of fracture fixation and avascular necrosis of the femoral head in trochanteric fractures has never been described. We present a study of six consecutive patients who underwent arthroplasty after cut-out of the lag screw fixation of a trochanteric fracture with Gamma Locking Nail. All six femoral heads were studied histologically and a clinical retrospective study was also performed. In all cases, we found homogeneous avascular necrosis of the femoral head; in all but one, revascularisation was present in every area examined. We suggest that after fixation of these trochanteric fractures with the Gamma Locking Nail, there is a transitory ischaemia, if the revascularisation is not enough to provide a strong support for the lag screw, it may result in late mechanical failure in these fractures.

Prospective randomized comparison between a dynamic hip screw and a mini-invasive static nail in fractures of the trochanteric area: preliminary results

OBJECTIVES

This study aimed at comparing the results obtained with a sliding screw plate and an experimental device including a small-diameter nail that can be placed with a mini-invasive approach and provides a stable fixation.

DESIGN

Randomized prospective study.

SETTING

University hospital.

PATIENTS

The study included two groups with thirty fractures of the trochanteric area.

INTERVENTIONS

In both groups, the surgical procedure was carried out on patients placed on a traction table in a supine position, under an x-ray amplifier. Sliding screw plates (THS) were set in place according to the usual open technique. Nails were placed through a twenty-millimeter supratrochanteric cutaneous incision. This experimental system comprised a locked intramedullary nail with two nonparallel seven-millimeter cervicocephalic screws.

MAIN OUTCOME MEASURES

The comparison between the two groups was based on the surgical procedure (time, duration of x-ray irradiation, and total blood loss); the initial postoperative period (complications, duration of hospital stay, and the time before returning home); the time before full weight bearing became effective; the functional and social recovery; mortality; and the quality of immediate and final anatomic restitution and healing.

RESULTS

Operating time (p < 0.001) and blood loss (p < 0.001) were lower in the nail group, and no blood transfusion was required. Postoperative pain (p < 0.01), time necessary to support full weight bearing (p < 0.02), and time before returning home (p < 0.05) were reduced in the nail group. All fractures healed in the same amount of time, with good anatomic results in the nail group, whereas ten impactions beyond ten millimeters occurred in the plate group. No difference was found between the two groups in walking ability and autonomy recovery, but hip function (p < 0.05) was better in the nail group.

CONCLUSION

This preliminary clinical study has shown the advantages of this mini-invasive technique. It could not evaluate all the possible disadvantages inherent in the method. These points will be evaluated in a multicenter study justified by these preliminary results.

Prospective randomized controlled trial of an intramedullary nail versus dynamic screw and plate for intertrochanteric fractures of the femur

OBJECTIVES

To compare the surgical complications and functional outcome of the Gamma nail intramedullary fixation device versus the Richards sliding hip screw and plate device in intertrochanteric femoral fractures.

DESIGN

A prospective, randomised controlled clinical trial with observer blinding.

SETTING

A regional teaching hospital in the United Kingdom.

PATIENTS

All patients admitted from the local population with intertrochanteric fractured femurs were included. There were 400 patients entered into the study and 399 followed-up to one year or death.

INTERVENTION

The devices were assigned by randomization to either a short-type Gamma nail (203 patients) or a Richard's-type sliding hip screw and plate (197 patients).

MAIN OUTCOME MEASUREMENTS

The main surgical outcome measurements were fixation failure and reoperation. A functional outcome of pain, mobility status, and range of movement were assessed until one year.

RESULTS

The requirement for revision in the Gamma nail group was twelve (6%); for Richard's group, eight (4%). This was not statistically different (p = 0.29; odds ratio, 1.48 [0.59-3.7]). A subcapital femoral fracture occurred in the Richard's group. Femoral shaft fractures occurred with four in the Gamma nail group (2%) and none in the Richard's group (p = 0.13). Three required revision to another implant. Lag-screw cut-out occurred in eight patients in the gamma nail group (4%) and four in the Richard's group (2%). This was not statistically significant (p = 0.37; odds ratio, 2.29 [0.6-9.0]). The development of other postoperative complications was the same in both groups. There was no difference between the two groups in terms of early or long-term functional status at one year.

CONCLUSIONS

The use of an intramedullary device in the treatment of intertrochanteric femoral fractures is still associated with a higher but nonsignificant risk of postoperative complications. Routine use of the Gamma nail in this type of fracture cannot be recommended over the current standard treatment of dynamic hip screw and plate.

Intramedullary femoral nails: one or two lag screws? A preliminary study

Failures of proximal femoral nails that treat unstable femoral fractures have been reported. In this communication, a finite element model to include a proximal femoral nail within a fractured femur was used to carry out preliminary investigations into configurations of single or double lag screws. The effects of the different types of fracture were investigated. The results show that in order to share the load evenly between two lag screws, a good configuration seems to be to have a slightly larger screw above the lower screw. This also ameliorates stresses in the nail at the lag screw insertion holes. However, using two screws in this way can lead to large stresses in the cancellous bone in the femoral head, and these stresses may be significant in the initiation of cut-out.