Superior short-term outcomes of FNS in combination with a cannulated screw in treating femoral neck fractures

BACKGROUND

This study aimed to evaluate the clinical efficacy of the femoral neck system alone or in combination with a cannulated screw compared with other internal fixation methods for treating femoral neck fractures. We further investigated the predictive effects of tip-apex distance (TAD) on clinical efficacy.

METHODS

Data from 129 young adults with femoral neck fractures followed up at The Second Affiliated Hospital of Fujian Medical University between January 2016 and June 2022 were retrospectively collected. The patients were categorized into four groups based on the different internal fixation methods. Analysis and comparisons of the four group were performed according to age, ASA score, operation time, blood loss, fracture classification, fracture healing time, Harris score, TAD value, presence of complications (osteonecrosis of the femoral head, screw failure, and femoral neck shortening), and changes in the neck-shaft angle.

RESULTS

All 129 patients were followed up for at least one year. The group who received treatment with the femoral neck system combined with a cannulated screw exhibited the shortest fracture healing time. Differences were observed in the change of neck-shaft angle among the four groups (P < 0.001), with the smallest change observed in the aforementioned group (0.76 ± 0.54°). The femoral neck shortening was also lower in groups with the femoral neck system or combined with a cannulated screw. At the last follow-up surgery, the combined treatment group achieved the highest HHS score. Subgroup analysis revealed that when the TAD was less than 25 and 49 mm for the femoral neck system and combined groups, respectively, there was less femoral neck shortening, less change in the neck-shaft angle, and a higher HHS score.

CONCLUSIONS

The femoral neck system alone or combined with a cannulated screw demonstrated better short-term efficacy in the treatment of femoral neck fractures. Furthermore, TAD may serve as a predictive indicator of the potential success of femoral neck fracture treatment.

How to place a cephalomedullary screw when visualization is obscured by the jig in peritrochanteric hip fractures using "peek radiographs."

Lag screw positioning can be difficult to discern intraoperatively on lateral fluoroscopic imaging during intramedullary fixation of proximal femur fractures in some nailing systems due to the drill guide handle obstructing the view. We have described a method of obtaining non-obstructed lateral-oblique "peek" views that reliably assist in obtaining adequate tip-apex distance (TAD) measurements when using intramedullary fixation for these fractures. The purpose of this study was (1) to describe an intraoperative radiographic technique to obtain non-obscured views for appropriate center-center placement of the lag screw(s) within the femoral head during jig-aided cephalomedullary nailing of peritrochanteric hip fractures and (2) to present a case series detailing the radiographic results using this technique. This clinical series of sixty-five patients with intertrochanteric or subtrochanteric proximal femur fractures stabilized with a cephalomedullary nail had an average TAD of 15.1 ± 3.3mm (range: 9.4mm-26.2mm). This suggests that our technical trick of obtaining "peek" radiographs intraoperatively may aid in a precise lag-screw placement.

Risk factors for excessive postoperative sliding of femoral trochanteric fracture in elderly patients: A retrospective multicenter study

INTRODUCTION

The application of a load on the internal fixation of a trochanteric fracture exerts a moment along the lag screw, causing the proximal bone fragment to slide along the lag screw, allowing contact between the proximal and distal bone fragments, which promotes healing. However, excessive sliding is related to poor postoperative outcomes. We aimed to identify the risk factors for excessive sliding.

MATERIALS AND METHODS

We conducted a multicenter retrospective study including 115 trochanteric fractures sustained through low-energy trauma in 19 male and 96 female patients aged 60 years or older (mean age: 82.9 years) between September 2013 and December 2014. We measured the postoperative sliding distance after osteosynthesis using a sliding hip screw or intramedullary nailing, and classified participants with ≥8 mm of sliding into the excessive sliding group (ESG) and with <8 mm into non-ESG. Finally, we investigated the risk factors of excessive postoperative sliding.

RESULTS

Fifty participants were classified into the ESG and 65 participants into the non-ESG. Female sex (p = 0.0264), an A3 fracture type (p = 0.0003), greater tip-apex distance (p = 0.0250), and poor reduction in either the anteroposterior or lateral radiographic views (p = 0.0156) were identified as risk factors for excessive sliding by multivariate regression analysis.

CONCLUSIONS

Female sex, an unstable fracture type, a greater tip-apex distance, and a poor reduction, in either the anteroposterior or lateral views, are associated with excessive postoperative sliding. Therefore, surgery should aim to achieve good reduction and stabilization from both radiographic views.

No difference between lag screw and helical blade for cephalomedullary nail cut-out a systematic review and meta-analysis

INTRODUCTION

Cephalomedullary nail (CMN) cut-out is a severe complication of treatment of intertrochanteric femur fractures. This study aimed to identify modifiable risk factors predictive of implant cut-out including: CMN proximal fixation type (lag screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, screw location, and surgeon fellowship training.

METHODS

A systematic review of the published literature was conducted on Pubmed/MEDLINE and Cochrane Library databases for English language papers (January 1st, 1985-May 10th, 2020), with 21 studies meeting inclusion/exclusion criteria. Studies providing quantitative data comparing factors affecting CMN nail cut-out were included, including fixation type (lag screw vs. helical blade), tip-apex distance (TAD), reduction quality, nail length, and screw location. Twelve studies were included and graded by MINOR and Newcastle-Ottawa Scale to identify potential biases. Meta-analysis and pooled analysis were conducted when possible with forest plots to summarize odds ratios (OR) and associated 95% confidence interval (CI).

RESULTS

There was no difference in implant cut-out rate between lag screws (n = 745) versus helical blade (n = 371) (OR: 1.03; 95% CI: 0.25-4.23). Pooled data analysis revealed TAD > 25 mm (n = 310) was associated with higher odds of increased cut-out rate relative to TAD < 25 mm (n = 730) (OR: 3.72; 95% CI: 2.06-6.72).

CONCLUSION

Our review suggests that cephalomedullary implant type (lag screw vs. helical blade) is not a risk factor for implant cut-out. Consistent with the previous literature, increased tip-apex distance > 25 mm is a reliable predictor of implant cut-out risk. Suboptimal screw location and poor reduction quality are associated with increased risk of screw cut-out.

LEVEL OF EVIDENCE

Level III.

Trochanteric fractures treated by internal fixation using short intramedullary nails: Does the visual intraoperative estimation of the Tip-Apex Distance (TAD) concur with its digital postoperative measurement?

INTRODUCTION

The tip-apex distance (TAD) is the only predictor for mechanical failure after internal fixation of trochanteric fractures. The main objective of our study was to assess whether the intraoperative visual estimation of the TAD concurred with the measurement taken on postoperative digital X-rays. We hypothesized that there was a good concordance between these 2 different methods of measurement.

MATERIALS AND METHODS

Patients with an isolated trochanteric fracture were included in our study. A hardcopy of the intraoperative X-rays were printed, and the TAD was calculated manually. Radiological and clinical follow-ups were scheduled at 6 weeks, 3 months and 6 months during which numerical measurements of the TAD were taken. We also recorded the fracture type (AO/OTA classification), degree of osteoporosis (Singh index), surgeon experience, age and ASA score.

RESULTS

A total of 98 patients were included in our study. Of these, 70 had a 6-month follow-up and interpretable postoperative X-rays. The mean age was 87 years, with 77.14% women and a mean ASA score of 3. The coefficient of concordance between the intra and postoperative TAD was 0.7202 (95% CI=0.4905-0.9499). The secondary displacement rate was 3.28%. The univariate analysis showed no statistically significant association between an intraoperative TAD>25mm and fracture type (p=0.7290), degree of osteoporosis (p=0.5701) and surgeon experience (p=1).

DISCUSSION/CONCLUSIONS

There was a high degree of concordance between intraoperative visual estimation of the TAD and its measurement on postoperative digital X-rays. The treatment of unstable fractures in osteoporotic bone by junior surgeons was not a risk factor for intraoperative TAD>25mm. It is therefore important to educate young surgeons on the concept of TAD and its intraoperative visual estimation technique as it ensures that the cephalic screw is positioned properly during the fixation of trochanteric fractures.

LEVEL OF EVIDENCE

II.

Varus displacement of intertrochanteric femur fractures on injury radiographs is associated with screw cutout

INTRODUCTION

The purpose of this study was to determine if varus displacement of intertrochanteric femur fractures on injury radiographs is associated with screw cutout after fixation.

METHODS

A retrospective review performed at two urban level 1 trauma centers identified 334 patients with intertrochanteric femur fractures treated with either a cephalomedullary nail (CMN) or a sliding hip screw (SHS). Median patient age was 75 years, 69% were female and 46% had unstable fractures. Varus fracture displacement on injury radiographs, defined as the most proximal aspect of the femoral head being at or below the most proximal aspect of the greater trochanter, was present in 38% of patients. Screw cutout was recorded.

RESULTS

Varus displacement was associated with unstable fracture patterns (62% vs. 37%, difference (D) 25%, 95% confidence interval (CI) 15-35%), female gender (77% vs. 64%, D 13%, CI 3-22%) and poor/adequate reductions (54% vs. 41%, D 13%, CI 2-23%). Cutout occurred in 9 (3%) patients, 8 of which had varus displacement. There was no detectable difference, with wide confidence intervals, between patients that did and did not experience cutout in terms of age, gender, unstable fractures, implants, tip-apex distance (TAD) or poor/adequate reductions. On univariate and multivariate analysis, varus displacement was the only variable associated with cutout. Patients with and without varus displacement had a cutout incidence of 6 and 0.5% (Odds ratio 13, CI 1.6-108).

CONCLUSION

Intertrochanteric fractures presenting with varus displacement were more likely to experience cutout. This potential risk factor for cutout warrants further study.

LEVEL OF EVIDENCE

Level 3, retrospective cohort.

A novel lower bound for tip-apex distance

PURPOSE

The cut-out of the cephalomedullary nail is among the most common post-surgery complications for intertrochanteric fractures. As a risk predictor, a tip-apex distance (TAD) below 25 mm, observed from orthogonal fluoroscopic views, is recommended in the literature. This study aims to demonstrate that TAD < 25 mm is a mathematically insufficient risk definition and to complement the TAD upper bound with an appropriate lower bound, with the introduction of a novel distance parameter, TADX, based on the orthogonal projection of the nail tip on the central femoral midline.

METHOD

Through a mathematical simulation software, all the possible points that lie inside the AP and lateral views of the proximal femoral hemisphere are utilized to create a 3D grid that is sorted into geometrically safe and risk-bearing regions. Extending this methodology, TAD < 25 mm, 10 mm < TAD < 25 mm, and the ideal tip position volumes are simulated. Finally, intersection volumes are created by a combination of different candidate lower TADX bounds and TAD < 25 mm upper bound to determine satisfactory TADX limits.

RESULTS

Simulation of TAD-bound zones exposed that TAD is only a mathematically suitable parameter for defining the upper boundary but not the lower boundary for the optimal region. However, using a TADX lower limit creates a 3D volume that is much closer to the optimal tip region volumetrically and can still be as quickly calculated from 2D AP and lateral views.

CONCLUSIONS

According to the mathematical simulations, the use of a TADX lower bound of 9 mm for small, 7.5 mm for medium, and 7 mm for large femoral heads in conjunction with a TAD upper bound of 25 mm is suggested.

Management of Low-Energy Basicervical Proximal Femoral Fractures by Proximal Femoral Nail Anti-Rotation

Objective

To evaluate clinical and radiological outcomes of proximal femoral nail anti‐rotation (PFNA‐II) devices and demonstrate the effectiveness of PFNA‐II for the treatment of basicervical fractures in elderly patients.

Methods

A retrospective review of all patients treated with PFNA‐II for a proximal femoral fracture between January 2013 and February 2017 at three different institutions (Shanghai General Hospital, Shanghai Punan Hospital and Shanghai Seventh People's Hospital) was conducted. The X‐ray films were strictly reviewed by three trauma surgeons and a professional radiology doctor. Patients over 60 years of age who met the following criteria were included: (i) sustained low‐energy trauma; (ii) a two‐part fracture; (iii) fracture line located at the base of the femoral neck and that was medial to the intertrochanteric line and exited above the lesser trochanter but was more lateral than a classic transcervical fracture. Follow‐up time should be longer than 6 months. A total of 52 patients who met the inclusion criteria were selected. The average age at diagnosis was 75.1 years (range, 63–91 years); 13 patients were men and 39 were women. The same proximal femoral nail anti‐rotation devices and the same surgical procedures were applied to all patients. Postoperative radiographic union time and modified Harris hip scores were used as major indicators for evaluating the effectiveness of surgery.

Results

The average follow‐up period was 22.5 months (18.5, 23.9, and 21.2 months, respectively) and radiographic unions were observed at an average of 19.6 weeks (range, 12–28 weeks). The patients were evaluated immediately after surgery, as well as 6 weeks, 3 months, 6 months, 1 year, and 2 years postoperatively. Of the 49 patients, 38 had good reduction qualities (75.5%), 9 acceptable (18.3%), and 3 poor (6.1%). Radiographic union was confirmed in all fractures at an average of 19.6 weeks (range, 12–28 weeks). The mean Harris hip score was 84.9 (range, 65–99): excellent in 9 patients (18.36%), good in 30 (61.22%), medium in 8 (16.32%), and poor in 2 (4.08%). Slight persistent pain occurred in 3 patients, but these patients could still walk with the help of a cane. Two patients had symptoms of excessive telescoping. Eight patients experienced postoperative medical complications, mainly pneumonia and urinary tract infection.

Conclusion

Based on the clinical and radiological outcomes, the PFNA‐II devices provide strong rotational stability and excellent clinical prognosis, and are an appropriate treatment option for basicervical proximal femoral fracture in elderly patients.

Tip-apex distance and other predictors of outcome in cephalomedullary nailing of unstable trochanteric fractures

BACKGROUND

Cephalomedullary nails are presently the gold standard in management of unstable trochanteric fractures. The tip-apex distance (TAD) is one of the most important factors that determines success or failure of fixation, but was described originally in context of an extramedullary hip screw. Cephalomedullary nails use a different biomechanical approach to fixation; and it is hypothesized that the TAD rule may not apply similarly with these. The aim of this study is to assess whether a high TAD correlates with poor outcomes with cephalomedullary nails, and to elucidate other factors that may predict such outcome.

METHODS

We retrospectively reviewed the clinical and radiographic records of patients with intertrochanteric fractures, treated at our institution over a 2-year period. Those with unstable fractures (31.A2 and 31.A3), and who were treated with cephalomedullary nails were included in the study. The TAD and the position of the device in the femoral head (Cleveland index) were assessed. Other factors that could influence outcome like age, gender, AO fracture type, restoration of neck-shaft angle and degree of osteoporosis were analysed. Radiographic records of up-to at-least 3 months post-operatively were assessed for complications.

RESULTS

After applying the exclusion criteria, 75 patients were included in the analysis. The overall rate of complications was 12%. They occurred in two major patterns - varus collapse and cut-out occurred in 5 patients (6.67%), and device migration in 4 patients (5.33%). The average TAD of patients with cut-out was 28.78 mm, compared to 19.44 mm in those without cut-out (p = 0.002). Our data predicted a cut-off TAD >23.56 mm as most significant for cut-out with cephalomedullary nails. On univariate logistic regression, high TAD (p = 0.009), sub-optimal device positioning (p = 0.02) and poor restoration of neck-shaft angle (p = 0.04) were found to be significant for varus collapse and cut-out, but not for complications relating to device migration. On multivariate analysis, none of the above factors reached statistical significance in isolation.

CONCLUSION

As with extramedullary devices, TAD, along with sub-optimal device positioning and poor restoration of neck-shaft angle is a useful predictor of cut-out even with cephalomedullary nails, negating the initial hypothesis. The above factors in combination have a more significant effect than any one factor in isolation to cause varus collapse and implant cut-out. However these do not affect Z effect, reverse Z effect or other types of device migration seen especially with dual-screw nails.

Implant cut-out following cephalomedullary nailing of intertrochanteric femur fractures: Are helical blades to blame?

INTRODUCTION

Implant cut-out remains a common cause of cephalomedullary nail (CMN) failure and patient morbidity following surgical treatment of intertrochanteric femur fractures. Recent studies have suggested an increased rate of CMN cut-out with helical blades as opposed to lag screws. We compared rates of overall cut-out between helical blades and lag screws and used bivariate and multivariate analysis to determine the role of proximal fixation method among other variables on risk for cut-out. Subgroup analysis was performed on the basis of failure mechanism; superior migration (Fig. 2) versus medial perforation (Fig. 3).

METHODS

Three-hundred and thirteen patient charts were retrospectively reviewed over an 8-year period; 245 patients were treated with helical blades and 68 with lag screws. Radiographs were reviewed for fracture pattern, Tip-Apex Distance (TAD), Parker's Ratio (PR) and reduction quality. Rate of implant cut-out was compared between groups and multiple logistic regression was used to analyze the ability of several independent variables to predict implant cut-out.

RESULTS

Twenty cut-outs occurred; 15 with helical blades and 5 with lag screws. No difference in the rate of cut-out was observed between the two groups (p = 0.45). Poor fracture reduction was found to be a significant predictor of implant failure via bivariate and multiple logistic regression analysis (p = <0.01, OR 23.573). Helical blade fixation, fracture instability, TAD ≥ 25, and PR ≥ 0.45 were not predictive of implant cut-out during multivariate analysis. Similarly, patient smoking status and surgeon trauma fellowship training did not significantly increase the odds of implant cut-out. Failure by medial perforation occurred in 12 instances, all involving helical blades. Failure by superior migration occurred at a significantly higher rate with lag screws than helical blades (p = 0.02).

CONCLUSION

CMN cutout is likely multifactorial. A direct association between helical blade fixation and implant cut-out was not observed in our study. Amongst modifiable risk factors for implant failure, poorer fracture reduction was predictive of failure by cut-out. Subgroup analysis highlights differing modes of failure between lag screws and helical blades which warrants further investigation. Ideal TAD during helical blade fixation remains unknown.

Optimising the tip-apex-distance in trochanteric femoral fracture fixation using the ADAPT-navigated technique, a longitudinal matched cohort study

INTRODUCTION

The annual incidence of proximal femoral fractures is 100-150/100,000 and continues to increase with an aging population. Cut-out of hip screws after fracture fixation has been quoted as 8% in the literature. The tip-apex distance (TAD) is the strongest predictor for cut-out after operative fracture stabilisation. The aim of this study was to evaluate the novel ADAPT system (Adaptive Positioning Technology, Stryker, USA), a navigation device for intramedullary nailing of trochanteric fractures and its effect on optimising the TAD. This is the first clinical study to evaluate this new technology.

METHODS

The study group of 36 consecutive patients with a pertrochanteric fracture underwent intramedullary nailing for fracture fixation using ADAPT technology, while the matched control group underwent conventional Gamma-3-nailing. Matching criteria included fracture classification, gender and age. We measured the operative time and the postoperative TAD in anteroposterior (AP) and lateral radiographs of the 72 patients.

RESULTS

The mean TAD using ADAPT was 16.9 mm (range 8.4-33.7 mm) compared with 24.9 mm (range 14.6-40.2 mm) in the reference group treated without ADAPT. Using the ADAPT system significantly improved (p < 0.0005) the accuracy of lag screw placement but had no effect on operating time in fixation of femoral pertrochanteric fractures.

CONCLUSION

Working with the novel ADAPT system for positioning the lag screw using the Gamma-3-nail led to a statistically highly significant reduction of the TAD compared to the reference group (p < 0.001). The ADAPT system proved to be a very useful device in achieving higher surgical standards for the treatment of trochanteric fractures with intramedullary nailing. It enables higher accuracy in screw positioning and therefore better placement of the implant.

Outcomes of Internal Fixation with Compression Hip Screws in Lateral Decubitus Position for Treatment of Femoral Intertrochanteric Fractures

Purpose

Internal fixation using compression hip screws (CHS) and traction tables placing patients in the supine position is a gold standard option for treating intertrochanteric fractures; however, at our institution, we approach this treatment with patients in a lateral decubitus position. Here, the results of 100 consecutive elderly (i.e., ≥45 years of age) patients who underwent internal fixation with CHS in lateral decubitus position are analyzed.

Materials and Methods

Between March 2009 and May 2011, 100 consecutive elderly patients who underwent internal fixation with CHS for femoral intertrochanteric fracture were retrospectively reviewed. Clinical outcomes (i.e., Koval score, Harris hip score [HHS]) and radiographic outcomes (i.e., bone union time, amount of sliding of lag screw, tip-apex distance [TAD]) were evaluated.

Results

Clinical assessments revealed that the average postoperative Koval score decreased from 1.4 to 2.6 (range, 0–5; P<0.05); HHS was 85 (range, 72–90); and mean bone union time was 5.0 (range, 2.0–8.2) months. Radiographic assessments revealed that anteroposterior average TAD was 6.95 (range, 1.27–14.63) mm; lateral average TAD was 7.26 (range, 1.20–18.43) mm; total average TAD was 14.21 (range, 2.47–28.66) mm; average lag screw sliding was 4.63 (range, 0–44.81) mm; and average angulation was varus 0.72°(range, −7.6°−12.7°). There were no cases of screw tip migration or nonunion, however, there were four cases of excessive screw sliding and six cases of varus angulation at more than 5°

Conclusion

CHS fixation in lateral decubitus position provides favorable clinical and radiological outcomes. This technique is advisable for regular CHS fixation of intertrochanteric fractures.

Risk factors for cut-out after internal fixation of trochanteric fractures in elderly subjects

INTRODUCTION

Proximal femoral fracture is associated with severe morbidity and mortality and high socioeconomic costs. The main mechanical complication of internal fixation in trochanteric fracture is lag-screw cut-out through the femoral head. Several factors are involved, but remain controversial. The aim of the present study was to determine risk factors for cut-out in internal fixation of extracapsular proximal femoral fracture.

METHODS

A single-center retrospective study was conducted on a continuous series of 228 patients aged over 75 years, operated on for trochanteric fracture by gamma3 nail or DHS screw plate between July 2009 and December 2014.

RESULTS

Thirteen patients experienced mechanical failure of the internal fixation (5.7%). Tip-apex distance (TAD) differed significantly between the group with cut-out (32.69mm) and the group with consolidation (23.70mm; p-value=0.003052). Cut-out rate was 0.89% in good reduction, versus 9.64% in moderate and 12.12% in poor reduction (p-value=0.002693). In contrast, there were no significant differences according to age, type of fracture, or severity of osteoporosis.

CONCLUSION

To minimize mechanical complications exacerbating morbidity and mortality, great attention should be paid to fracture reduction and lag-screw positioning.

LEVEL OF EVIDENCE

IV, retrospective study.

Intramedullary versus extramedullary internal fixation for unstable intertrochanteric fracture, a meta-analysis

OBJECTIVE

The aim of this meta-analysis was to explore the difference between and compare intramedullary fixation (IF) and extramedullary fixation (EF) for unstable intertrochanteric fractures.

METHODS

We searched Pubmed database and Cochrane library following by including and excluding articles based from inception to December, 2016. All randomized controlled trials (RCTs) comparing IF and EF for unstable intertrochanteric fractures were assessed and selected by two researchers independently. Data were analyzed using Review Manager 5.1 version.

RESULTS

17 RCTs were enrolled in our meta-analysis comparing IF and EF and showed evidence that IF had lower rate of implant failure RR = 0.2695%CI 0.13-0.51, P < 0.0001 and re-operation (RR = 0.60, 95%CI 0.37-0.98, P = 0.04), while there was no statistical differences of cut-out, postoperative infections and other complications. Moreover, PPM scores verified that IF had better postoperative hip mobility recovery (MD = 0.87, 95%CI 0.08-1.66, P = 0.03).

CONCLUSION

IF has lower incidence of failure of implant and reoperation and shows better postoperative functional recovery when treating adult unstable intertrochanteric fracture while the most postoperative complications were not statistically different from EF.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Intraoperative lateral wall fractures during Dynamic Hip Screw fixation for intertrochanteric fractures-Incidence, causative factors and clinical outcome

INTRODUCTION

The intact lateral wall plays a key role in stabilization of trochanteric fracture. Hence extreme precaution should be taken to prevent lateral wall damage during DHS fixation. Present study is aimed at evaluating the determinants of lateral wall fracture and its effect on outcome in intertrochanteric fracture femur treated with DHS.

MATERIAL AND METHODS

This is a prospective study involving intertrochanteric fractures treated with DHS fixation from July 2013 to June 2014. Out of 135 patients 49(36.3%) had stable fractures and 86(63.7%) unstable fractures. Cortical thickness index (CTI) was measured to evaluate osteoporosis. Lateral wall thickness in anteroposterior radiograph was also measured.All patients underwent 135° DHS fixation.Postoperative x-rays are assessed for implant position, intactness of the lateral wall, tip apex distance (TAD) and medialization. Functional outcome was measured at the end of fracture union by modified Harris hip score and Parkers mobility score. Clinical information including age, gender, fracture classification, TAD, lateral wall thickness and functional outcome of the patients were subjected to statistical analysis.

RESULTS

34 (19.5%) patients had lateral wall fractures. Medialization was found in 22 out of these 34 (64.7%) patients. The mean preoperative lateral wall thickness of these patients is 19.2mm, compared with 26.8mm in patients with intact lateral wall (p<0.001). The mean values of CTI and TAD are comparable in both the groups. In patients with intact lateral wall, mean Harris hip score is 73.1 compared to 65.5 in lateral wall fracture group (p<0.001). Preinjury mobility status was achieved in 70.2% of intact lateral wall patients, whereas only 32.3% (11) achieved that in lateral wall fracture group. Threshold for lateral wall thickness that could predict lateral wall fracture was found to be 21mm with 95% sensitivity and 88.2% specificity.

CONCLUSION

Lateral wall fractures during DHS fixation are not uncommon and osteoporosis has no bearing on its occurrence. It alone can lead to poor radiological and functional outcome independent of TAD. Lateral wall thickness is a reliable predictor of intra operative lateral wall fracture during DHS fixation and nailing is a good option especially when lateral wall thickness is <21mm.

Late postoperative analysis of the tip-apex distance (TAD) in pertrochanteric fractures: is there an accommodation of the implant within the bone?

INTRODUCTION

This study measured the tip-apex distance (TAD) values in the immediate postoperative period and following weight-bearing and fracture impaction in patients undergoing osteosynthesis with dynamic hip screw and cephalomedullary nail.

OBJECTIVE

To correlate the Baumgaertner index in the immediate postoperative period with values obtained after impaction of the fracture with the accommodation of the cephalic implant in the femoral head.

PATIENTS AND METHODS

Radiographic TAD measurements were taken with AGFA-VIEW^® of 82 patients with a mean age of 72 years with pertrochanteric fractures who were operated on and the fracture fixed with DHS- Synthes^®, TFN-Synthes^®, or Gamma Nail III-Stryker^® in the immediate postoperative period, and following weight-bearing and fracture impaction (mean 3-8 weeks after surgery).

RESULTS

The overall average TAD decreased from 20.3mm to 18.2mm. Regardless of the instability of the fracture, the age of the patient or the implant used, TAD decreased between the immediate postoperative period and following fracture impaction.

CONCLUSION

The osteosynthesis of pertrochanteric fractures was associated with important accommodation of the cephalic implant in the femoral head with decreased TAD values after weight-bearing.

A six-year retrospective analysis of cut-out risk predictors in cephalomedullary nailing for pertrochanteric fractures: Can the tip-apex distance (TAD) still be considered the best parameter?

Objectives

Intramedullary fixation is considered the most stable treatment for pertrochanteric fractures of the proximal femur and cut-out is one of the most frequent mechanical complications. In order to determine the role of clinical variables and radiological parameters in predicting the risk of this complication, we analysed the data pertaining to a group of patients recruited over the course of six years.

Methods

A total of 571 patients were included in this study, which analysed the incidence of cut-out in relation to several clinical variables: age; gender; the AO Foundation and Orthopaedic Trauma Association classification system (AO/OTA); type of nail; cervical-diaphyseal angle; surgical wait times; anti-osteoporotic medication; complete post-operative weight bearing; and radiological parameters (namely the lag-screw position with respect to the femoral head, the Cleveland system, the tip-apex distance (TAD), and the calcar-referenced tip-apex distance (CalTAD)).

Results

The incidence of cut-out across the sample was 5.6%, with a higher incidence in female patients. A significantly higher risk of this complication was correlated with lag-screw tip positioning in the upper part of the femoral head in the anteroposterior radiological view, posterior in the latero-lateral radiological view, and in the Cleveland peripheral zones. The tip-apex distance and the calcar-referenced tip-apex distance were found to be highly significant predictors of the risk of cut-out at cut-offs of 30.7 mm and 37.3 mm, respectively, but the former appeared more reliable than the latter in predicting the occurrence of this complication.

Conclusion

The tip-apex distance remains the most accurate predictor of cut-out, which is significantly greater above a cut-off of 30.7 mm.

Cite this article: G. Caruso, M. Bonomo, G. Valpiani, G. Salvatori, A. Gildone, V. Lorusso, L. Massari. A six-year retrospective analysis of cut-out risk predictors in cephalomedullary nailing for pertrochanteric fractures: Can the tip-apex distance (TAD) still be considered the best parameter?. Bone Joint Res 2017;6:481–488. DOI: 10.1302/2046-3758.68.BJR-2016-0299.R1.

Prospective randomized study comparing two cephalomedullary nails for elderly intertrochanteric fractures: Zimmer natural nail versus proximal femoral nail antirotation II

OBJECTIVES

Although both clinical and biomechanical studies suggest that cephalomedullary implants have a mechanical advantage over extramedullary implants, a high rate of complications or implant failure remains in elderly patients with osteoporosis. In an attempt to address some of these challenges, new implants with improved designs named proximal femoral nail antirotation II (PFNA II) and Zimmer natural nail (ZNN) were developed for elderly patients. Although the PFNA II reportedly has good clinical outcomes, it is unclear which implant achieves better safety and efficacy for treating intertrochanteric hip fractures. The primary objective of this prospective, randomized trial involved 353 patients was to evaluate Harris Hip Score (HHS). The secondary objective was to compare results associated with clinical outcome such as operation time, fluoroscopy time, lateral hip pain, walking ability, and reoperation rate as well as the incidence of cut-out by using implant position and fracture reduction quality.

METHODS

353 patients with an intertrochanteric fracture amenable to either ZNN implant or PFNA II with a mean age of 77.0 years and a mean follow-up period of 12.3 months were included. We analyzed 353 patients with an intertrochanteric fracture treated using a ZNN implant (n=172, group I) or a PFNA II (n=181, group II) between January 2011 and August 2014.

RESULTS

There were no significant inter-group differences in HHS, walking ability, and reoperation rate were observed. However, operation and fluoroscopy time were significantly different between the two groups as well as group I showed a higher incidence of lateral hip pain than group II. In addition, no significant inter-group differences in cut-out rate determined by implant position and fracture reduction quality. We also found that cut-out was associated with lag screw position in the femoral head measured by Tip-apex distance (TAD) but not with reduction quality.

CONCLUSIONS

Although group I had significant longer operation and fluoroscopy time than group II, both implants are useful tools in the treatment of elderly intertrochanteric fractures as well as only TAD, but not Cleveland zone significantly correlated with lag screw cut-out.

The tip-apex distance in the X-Bolt dynamic plating system

OBJECTIVES

The Sliding Hip Screw (SHS) is commonly used to treat trochanteric hip fractures. Fixation failure is a devastating complication requiring complex revision surgery. One mode of fixation failure is lag screw cut-out which is greatest in unstable fracture patterns and when the tip-apex distance of the lag screw is > 25 mm. The X-Bolt Dynamic Hip Plating System (X-Bolt Orthopaedics, Dublin, Ireland) is a new device which aims to reduce this risk of cut-out. However, some surgeons have reported difficulty minimising the tip-apex distance with subsequent concerns that this may lead to an increased risk of cut-out.

PATIENTS AND METHODS

We measured the tip-apex distance from the intra-operative radiographs of 93 unstable trochanteric hip fractures enrolled in a randomised controlled trial (Warwick Hip Trauma Evaluation, WHiTE One trial). Participants were treated with either the sliding hip screw or the X-Bolt dynamic hip plating system. We also recorded the incidence of cut-out in both groups, at a median follow-up time of 17 months.

RESULTS

There was a significantly increased tip-apex distance with the use of the X-Bolt (mean difference 3.7mm (95% confidence interval 1.58 to 5.73); SHS mean 17.1 mm, X-Bolt mean 20.8; p = 0.001. However, this was not associated with an increased incidence of cut-out at a median follow-up time of 17 months, with three cut-outs (6%) in the SHS group and 0 (0%) in the X-Bolt group.

CONCLUSION

The X-Bolt is a safe implant with no increased risk for cut-out. Concerns about minimising the tip-apex distance may be justified but do not appear to be clinically important.Cite this article: M. A. Fernandez, A. Aquilina, J. Achten, N. Parsons, M. L. Costa, X. L. Griffin. The tip-apex distance in the X-Bolt dynamic plating system. Bone Joint Res 2017;6:-207. DOI: 10.1302/2046-3758.64.BJR-2015-0016.R2.

Risk factors for cut-out of double lag screw fixation in proximal femoral fractures

OBJECTIVE

We assessed factors associated with cut-out after internal fixation of proximal femoral fractures using double lag screw nails.

DESIGN

Retrospective cohort study.

SETTING

A university hospital.

PATIENTS AND METHODS

Patients with non-pathological intertrochanteric femur fractures and a minumum 90days follow-up who underwent internal fixation with dual lag screw nails were included. Potential risk factors for lag screw cut-out investigated by our study were: age, gender, body mass index, comorbidities (American Society of Anesthesiologists [ASA] classification), type of fracture (AO/OTA classification), fracture stability, side, operation time, implant length, reduction quality, tip-apex distance (TAD), and lag screw configuration. Logistic regression was used to investigate potential predictors of screw cut-out.

RESULTS

Eighty-five of the 118 patients with hip fractures treated between February 2010 and November 2013 at our institution met the inclusion criteria for the study. Fifty-eight patients were female (68.2%), mean age was 77.4 (range: 50-95 years), mean follow up was 380days (range: 150days-2.5 years), and cut of was observed in 9 patients (10.5%). The following variables identified through univariate analysis with p<0.2 were included in multivariant logistic regression model: age, side, reduction quality, implant length, TAD and ASA score. Only TAD (p=0.003) was found to be significant in the multivariant model.

CONCLUSIONS

Our study confirmed that risk factors for cut-out with single-lag screw devices are also applicable to dual-lag screw implants. We found that TAD was a significant factor for cut-out in dual-lag screw implants. Thus, screw cut-out can be minimized by optimizing screw position.

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.

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.